ORTHOPEDIC MCQS WITH ANSWER SPINE 03

1.         The transverse diameter of the pedicle is most narrow at which of the following levels?

 

1-         T1

2-         T5

3-         T9

4-         T12

5-         L5

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Of the levels given, T5 has the most narrow pedicle in anatomic studies.  One study in patients with scoliosis did note that T7 on the concave side was more narrow than T5, but T7 is not listed here as a possible answer.

 

REFERENCES: O’Brien MF, Lenke LG, Mardjetko S, et al: Pedicle morphology in thoracic adolescent idiopathic scoliosis: Is pedicle fixation an anatomically viable technique?  Spine 2000;25:2285-2293.

Vaccaro AR, Rizzolo SJ, Allardyce TJ, et al: Placement of pedicle screws in the thoracic spine: Part I. Morphometric analysis of the thoracic vertebrae.  J Bone Joint Surg Am
1995;77:1193-1199.

 

 

2.         Subluxation caused by rheumatoid arthritis is most commonly seen at what level of the cervical spine?

 

1-         Occiput-C1

2-         C1-C2

3-         C2-C3

4-         C3-C4

5-         C4-C5

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Approximately 65% of cervical subluxations occur at C1-C2.  Of these, 50% are anterior, with the remainder being lateral and posterior.  The second most common type is basilar invagination, occurring in 40% of patients.  The third most common type is subaxial, occurring in 20% of patients with rheumatoid arthritis.  Subluxation at more than one level is common.

 

REFERENCES: Boden S, Clark CR: Rheumatoid arthritis of the cervical spine, in Clark CR (ed): The Cervical Spine, ed 3. Philadelphia, PA, Lippincott Raven, 1998, p 693.

Boden SD, Dodge LD, Bohlman HH, Rechtine GR: Rheumatoid arthritis of the cervical spine: A long-term analysis with predictors of paralysis and recovery.  J Bone Joint Surg Am 1993;75:1282-1297.

Koval KJ (ed): Orthopaedic Knowledge Update 7.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 689-701.

 

 

3.         During a transperitoneal approach to the L5-S1 interspace, care must be taken to protect the superior hypogastric plexus from injury.  Which of the following techniques reduces the risk of neurologic injury?

 

1-         Transverse incision across the posterior peritoneum and disk space, reflecting the tissues toward the sacral promontory

2-         Transverse incision across the posterior peritoneum and disk space, reflecting the tissues toward the confluence of the iliac veins

3-         Vertical midline incision of the posterior peritoneum, reflecting the prevertebral tissues beginning at the margin of the left iliac vein and extending toward the right iliac vein

4-         Vertical midline incision of the posterior peritoneum, reflecting the prevertebral tissues beginning at the margin of the right iliac vein extending toward the left iliac vein

5-         Vertical midline incision of the posterior peritoneum, reflecting the prevertebral tissues bilaterally away from the midline

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Retrograde ejaculation is the sequela of superior hypogastric plexus injury.  This structure needs protection, especially during anterior exposure of the L5-S1 disk space.  Only blunt dissection should be used, and use of monopolar electrocautery should be avoided.  If possible, preserve and retract the middle sacral artery.  Once the iliac veins are isolated, blunt dissection is begun along the course of the medial edge of the left iliac vein, reflecting the prevertebral tissues toward the patient’s right side.  The dissection goes from left to right because the parasympathetic plexus is more adherent on the right side.

 

REFERENCE: Transperitoneal midline approach to L4-S1, in Watkins RG (ed): Surgical Approaches to the Spine, ed 1.  New York, NY, Springer Verlag, 1983, pp 123-129.

 

 

 

 

4.         When treating thoracolumbar spine fractures, which of the following is considered the major advantage of using a thoracolumbosacral orthosis (TLSO) when compared to a three-point fixation brace (Jewett)?

 

1-         Patient compliance

2-         Cost

3-         Greater rotational control

4-         Greater flexion and extension control

5-         Less force on the lumbosacral junction

 

PREFERRED RESPONSE: 3

 

DISCUSSION: When treating thoracolumbar spine fractures, the major advantage of using the TLSO is greater rotational control.

 

REFERENCES: Levine AM (ed): Orthopaedic Knowledge Update: Trauma.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1996, pp 347-349.

Krompinger WJ, Fredrickson BE, Mino DE, Yuan HA: Conservative treatment of fractures of the thoracic and lumbar spine.  Orthop Clin North Am 1986;17:161-170.

Stauffer ES (ed): Thoracolumbar Spine Fractures without Neurological Deficit. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1993.

 

 

 

 

5.         Injury to which of the following structures has been reported following iliac crest bone graft harvest?

 

1-         Superior gluteal artery from an anterior crest harvest

2-         Superior cluneal nerve from an anterior crest harvest

3-         Inferior gluteal artery from a posterior crest harvest

4-         Ilioinguinal nerve from a posterior crest harvest

5-         Lateral femoral cutaneous nerve from an anterior crest harvest

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Injury to the lateral femoral cutaneous nerve and the ilioinguinal nerve have both been described with an anterior iliac crest bone graft harvest.  The lateral femoral cutaneous nerve may be injured from retraction after elevating the iliacus muscle or from direct injury when the nerve actually courses over the crest.  A posterior crest harvest can injure the superior gluteal artery if a surgical instrument violates the sciatic notch.  Injury to the inferior gluteal artery has not been described; it leaves the pelvis below the piriformis muscle belly and should not be at risk even with a violation of the sciatic notch.  Injury to the ilioinguinal nerve has been reported from vigorous retraction of the iliacus muscle after exposing the inner table of the anterior ilium.  Cluneal nerve injury may occur with posterior crest harvest, particularly if the skin incision is horizontal or extends more than 8 cm superolateral from the posterior superior iliac spine.

 

REFERENCES: Kurz LT, Garfin SR, Booth RE Jr: Iliac bone grafting: Techniques and complications of harvesting, in Garfin SR (ed): Complications of Spine Surgery.  Baltimore, MD, Williams and Wilkins, 1989, pp 323-341.

Anderson JE: Grant’s Atlas of Anatomy, ed 7.  Baltimore, MD, Williams and Wilkins, 1978,
pp 4-33 to 4-34.

 

 

 

 

6.         A 44-year-old woman has had lower extremity dysesthesias, urinary incontinence, and has been unable to walk for the past 2 days.  She reports no pain or history of trauma.  She notes that 3 weeks ago she missed work for 2 days because of back pain, but it resolved with rest.  Examination shows decreased or absent sensation below the knees, no motor function below the knees, and decreased rectal tone.  Catheterization results in a postvoid residual of 2,000 mL.  Plain radiographs and MRI scans without contrast are shown in Figures 1a through 1d.  What is the next most appropriate step in management?

 

1-         Physical therapy for functional rehabilitation

2-         CT/myelography of the spinal axis

3-         MRI with gadolinium

4-         Psychiatric consultation for possible malingering

5-         Lumbar puncture for analysis of cerebrospinal fluid

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The patient has had a clear and sudden onset of a profound neurologic deficit.  The radiographic studies suggest a lesion in the conus medullaris that appears to be intradural and intramedullary.  MRI, with and without contrast, will best evaluate this mass further.  The addition of gadolinium allows further evaluation of vascularity and the extent of the lesion.

 

REFERENCES: Eichler ME, Dacey RG: Intramedullary spinal cord tumors, in Bridwell KH, Dewald RL (eds): The Textbook of Spine Surgery, ed 2.  Philadelphia, PA, Lippincott-Raven, 1997, vol 2, pp 2089-2116.

Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 81-87.

 

 

 

 

7.         During anterior surgery on the cervical spine, at what level would the lateral dissection of the longus coli muscle most likely cause Horner’s syndrome?

 

1-         C3

2-         C4

3-         C5

4-         C6

5-         C7

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The sympathetic chain approaches the lateral border of the longus coli muscle at C6 and is more vulnerable to injury at this level.  Injury to the chain will cause Horner’s syndrome, usually seen as unilateral ptosis.

 

REFERENCE: Ebraheim NA, Lu J, Yang H, Heck BE, Yeasting RA: Vulnerability of the sympathetic trunk during the anterior approach to the lower cervical spine. 
Spine 2000;25:1603-1606.

 

 

8.         When compared with cobalt-chromium and stainless steel implants, a titanium implant has what biomechanical properties?

 

1-         Lower modulus of elasticity

2-         Improved notch sensitivity

3-         Increased hardness

4-         Increased risk of corrosion

5-         Decreased biocompatibility

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Titanium implants are commonly used in spinal surgery, especially when MRI may be needed after implantation.  Titanium implants have a lower modulus of elasticity when compared with cobalt-chromium and stainless steel implants.  This is felt to allow less stress shielding for these types of implants.  The other properties do not apply to titanium implants.

 

REFERENCE: Buckwalker JA, Einhorn TA, Simon SR (ed): Orthopedic Basic Science: Biology and Biomechanics of the Musculoskeletal System, ed 2.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 182-215.

 

 

 

 

9.         A 22-year-old college basketball player who was hit from behind while going up for a rebound is rendered immediately quadraparetic for approximately 10 minutes, followed by complete resolution of motor loss and return of full sensation.  The radiograph and MRI scan of the cervical spine shown in Figures 2a and 2b reveal a canal diameter of 13 mm, loss of cerebrospinal fluid space about the spinal cord, and no signal change within the cord.  What is the best course of action?

 

1-         Cease participation in all sports.

2-         Allow a return to noncontact sports after surgical decompression and stabilization.

3-         Allow a return to basketball 1 week after resolution of all symptoms.

4-         Discuss the relative risks with the player, parents, and coach regarding participation in the athlete’s sport of choice.

5-         Advise participation in noncontact sports only.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The correct decision on return to sports participation after episodes of transient quadraparesis is controversial.  Cantu and Mueller feel strongly that the loss of cerebrospinal fluid space about the spinal cord signifies an unacceptable risk for future spinal cord injury if the athlete returns to sports.  However, Watkins and Torg and Lasgow have reported no evidence of increased spinal cord injury in athletes with narrow spinal canals, even in football.  These authors suggest judgment be used in advising return to contact or high-energy sports and that the physician’s responsibility is to give accurate and relevant information, allowing the athlete to make his or her own choice regarding return to sports participation.

 

REFERENCES: Cantu R, Mueller FO: Catastrophic spine injuries in football (1977-1989). 
J Spinal Disord 1990;3:227-231.

Watkins RG: Neck injuries in football players.  Clin Sports Med 1986;5:215-246.

Torg JS, Lasgow SG: Criteria for return to contact activities following cervical spine injury.  Clin Sports Med 1991;1:12-26.

Morganti C, Sweeney CA, Albanese SA, Burak C, Hosea T, Connolly PJ: Return to play after cervical spine injury.  Spine 2001;26:1131-1136.

 

 

 

 

10.       A 40-year-old woman has local back pain and intense burning pain in her perianal region after being shot twice in the back.  Motor and sensory examination of her lower extremities reveals no apparent deficit.  She has present but decreased sensation in her perianal region, an intact anal wink, good rectal tone, and an intact bulbocavernosus reflex.  Radiographs and CT scans are shown in Figures 3a through 3d.  What is the next most appropriate step in management?

 

1-         Initiation of spinal cord injury steroid protocol

2-         MRI of the lumbar spine

3-         Immobilization in a thoracolumbosacral orthosis

4-         Removal of the metallic fragments via laminectomy

5-         Removal of the metallic fragments and posterior fusion with instrumentation

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Because the patient has an apparent compressive neuropathy secondary to the metallic fragments, removal of the fragments in this incomplete lesion at the cauda equina level can be expected to improve her sensory dysesthesias and pain.  Steroids are not indicated in a root lesion secondary to a penetrating injury.  MRI will have significant artifact effect and will not provide much additional information.  The posterior bony elements are not significantly injured; therefore, stabilization is not indicated.

 

REFERENCES: Bracken MB, Shepard MJ, Holford TR: Administration of methylprednisolone for 24 or 48 hours or tirilazad mesylate for 48 hours in the treatment of acute spinal cord injury.  JAMA 1997;277:1597-1604.

Waters RL, Adkins RH: The effects of removal of bullet fragments retained in the spinal canal:  A collaborative study by the National Spinal Cord Injury Model Systems.  Spine
1991;16:934-939.

Stauffer ES, Wood RW, Kelly EG: Gunshot wounds of the spine: The effects of laminectomy. 
J Bone Joint Surg Am 1979;61:389-392.

 

 

 

 

11.       A patient who sustained injuries in a motorcycle accident 30 minutes ago has significant motor and sensory deficits corresponding to a C6 level of injury.  A lateral radiograph obtained during the initial on-scene evaluation reveals bilateral jumped facets at C5-C6; this appears to be an isolated injury.  The patient is awake and alert.  The next step in management of the dislocation should consist of

 

1-         immediate posterior surgical reduction and stabilization.

2-         immediate anterior diskectomy and fusion.

3-         MRI.

4-         reduction in Gardner-Wells tongs with serial traction.

5-         rigid collar immobilization until spinal shock resolves.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Surgical open reduction may increase the neurologic deficit if a disk herniation exists.  Evidence from animal studies suggests that rapid decompression of the spinal cord may improve recovery.  Serially increasing traction weight to reduce the dislocation has been shown to be safe when used in patients who are awake.  Indications for MRI include patients who are unable to cooperate with serial examinations, the need for open reduction, and progression of deficit during awake reduction.

 

REFERENCES: Delamarter RB, Sherman J, Carr JB: Pathophysiology of spinal cord injury: Recovery after immediate and delayed decompression.  J Bone Joint Surg Am
1995;77:1042-1049.

Star AM, Jones AA, Cotler JM, Balderston RA, Sinha R: Immediate closed reduction of cervical spine dislocations using traction.  Spine 1990;15:1068-1072.

Eismont FJ, Arena MJ, Green BA: Extrusion of an intervertebral disc associated with traumatic subluxation or dislocation of cervical facets: Case report.  J Bone Joint Surg Am
1991;73:1555-1560.

 

 

 

 

12.       Figure 4 shows the MRI scan of a patient who has had bilateral leg pain, weakness, diffuse numbness, and urinary retention for the past week.  Examination reveals that motor strength is diffusely decreased, although it may be secondary to pain.  The patient is numb throughout both legs, and reflexes in the lower extremities are absent.  Rectal examination shows decreased tone, but voluntary tightening is present.  Management should consist of

 

1-         physical therapy and nonsteroidal anti-inflammatory drugs for 4 to 6 weeks.

2-         physical therapy, nonsteroidal anti-inflammatory drugs for 4 to 6 weeks, and methylprednisolone.

3-         epidural steroid injections.

4-         elective surgery.

5-         urgent surgery.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The patient has a cauda equina syndrome.  The fact that he has decreased rectal tone and urinary retention suggests the need for urgent surgery.  Patients who are left untreated will have a poor prognosis for return of function.  Although most patients who have insidious onset of symptoms with urinary retention will regain normal motor function following decompression, nearly one third will continue to have abnormal voiding patterns or sexual dysfunction of varying degrees.

 

REFERENCES: Kostuik JP, Harrington I, Alexander D, Rand W, Evans D: Cauda equina syndrome and lumbar disc herniation.  J Bone Joint Surg Am 1986;68:386-391.

Wisneski RJ, Garfin SR, Rothman RH, Lutz GE: Lumbar disk disease, in Herkowitz HN, Garfin SR, Balderston RA, et al (eds): The Spine, ed 4.  Philadelphia, PA,WB Saunders, 1992, vol 1,
pp 613-679.

 

 

 

 

13.       A 62-year-old man has cervical myelopathy with no evidence of cervical radiculopathy.  MRI reveals stenosis at C4-5 and C5-6 with severe cord compression.  Examination will most likely reveal which of the following findings?

 

1-         Spastic gait and a positive Hoffman’s sign

2-         Severe arm pain with upper extremity hyporeflexia

3-         Normal neurologic findings

4-         Hyperactive jaw jerk reflex with extremity numbness

5-         Flaccid paraparesis

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Cervical myelopathy involves compression of the spinal cord and presents as an upper motor neuron disorder.  Patients commonly have extremity spasticity and problems with ambulation and balance.  Hoffman’s sign is often present and is elicited by suddenly extending the distal interphalangeal joint of the middle finger; reflexive finger flexion represents a positive finding.  The extremities are usually hyperreflexic with myelopathy.  With cervical radiculopathy (lower motor neuron disorder), reflexes are hyporeflexic, and patients report pain along a dermatomal distribution.  A hyperactive jaw jerk reflex indicates pathology above the foramen magnum or in some cases, systemic disease.  Flaccid paraparesis suggests a lower motor neuron problem.

 

REFERENCES: Sachs BL: Differential diagnosis of neck pain, arm pain and myelopathy, in Clark CR (ed): The Cervical Spine, ed 3.  Philadelphia, PA, Lippincott Raven, 1998, pp 741-742.

Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 673-680.

 

 

 

 

14.       A patient who has had neck pain radiating down the arm for the past 4 weeks reports that the pain was excruciating during the first week.  Management consisting of anti-inflammatory drugs and physical therapy has decreased the neck and arm symptoms from 10/10 to 3/10.  He remains neurologically intact.  MRI and CT scans are shown in Figures 5a and 5b.  The best course of action should be

 

1-         immediate hospital admission and surgery because of the risk of paralysis.

2-         surgery within 24 hours.

3-         surgery within the next several days.

4-         elective surgery at the next available surgical date.

5-         additional nonsurgical management.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Although the patient has a large herniated nucleus pulposus, the pain has decreased from 10/10 to 3/10 over a 4-week period and the patient is now free of any neurologic symptoms.  It is quite likely that further nonsurgical management will continue to resolve his symptoms.  In the absence of any neurologic deficits, there is no evidence that the patient is at significant risk for paralysis.

 

REFERENCES: Saal JS, Saal JA, Yurth EF: Nonoperative management of herniated cervical intervertebral disc with radiculopathy.  Spine 1996;21:1877-1883.

Komori H, Shinomiya K, Nakai O, Yamaura I, Takeda S, Furuya K: The natural history of herniated nucleus pulposus with radiculopathy.  Spine 1996;21:225-229.

 

 

 

 

15.       Examination of a supine patient in which the hip is abducted, externally rotated, and flexed is referred to as

 

1-         Beevor’s sign.

2-         Lasegue’s sign.

3-         Kernig’s sign.

4-         femoral stretch test.

5-         Patrick’s test.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: During Patrick’s test, also known as the FABER test, the flexed, abducted, and externally rotated hip is positioned to isolate sacroiliac pathology.  Back pain with this test is not considered diagnostic.  With Kernig’s sign, the spinal cord is placed on stretch, eliciting root or meningeal irritation by forcibly flexing the patient’s head and neck with his or her hands clasped behind the head.  For Lasegue’s sign, the patient performs a straight leg raise with the immobile hip already held in flexion.  The femoral stretch test can be performed in the prone position or side lying, but the hip is held in extension while the knee is flexed, testing for femoral neuritis.

 

REFERENCES: Watkins RG: History, physical examination, and diagnostic tests for back and lower extremity problems, in Watkins RG (ed): The Spine in Sports.  St Louis, MO, Mosby, 1996, Chapter 7.

Hoppenfeld S: Physical Examination of the Spine and Extremities.  East Norwalk, CT, Appleton-Century-Crofts, 1976, Chapter 9.

 

 

 

 

16.       During the evaluation of a patient suspected of having a lumbar disk herniation, T1- and T2-weighted MRI scans reveal a hyperintence lobular, well-defined lesion in the L2 vertebral body.  What is the most likely diagnosis?

 

1-         Metastatic focus

2-         Bony island

3-         Intravertebral disk herniation

4-         Osteoporosis

5-         Hemangioma

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The findings are characteristic of hemangioma. When the hemangioma is large enough, vertical striations may be visible on plain radiographs. Axial CT scans commonly reveal a speckled appearance. Metastatic lesions are typically hypointense on T1-weighted images because they replace the fatty marrow. Bony islands, like cortical bone, are dark on T1- and T2-weighted images. Intravertebral disk herniation would have characteristics similar to the disk and be in continuity with the disk. Osteoporosis is more diffuse. 

 

REFERENCES: Ross JS, Masaryk TJ, Modic MT, Carter JR, Mapstone T, Dengel FH: Vertebral hemangiomas: MR imaging.  Radiology 1987;165:165-169.

Garfin SR, Vaccaro AR(eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 235-256.

 

 

 

 

17.       A 32-year-old man notes increasing back pain and progressive paraparesis over the past few weeks.  He is febrile, and laboratory studies show a WBC of 12,500/mm3.  MRI scans are shown in Figures 6a and 6b.  Management should consist of

 

1-         CT-guided needle aspiration and organism-appropriate antibiotics.

2-         laminectomy and postoperative bracing.

3-         posterior fusion with instrumentation and IV antibiotics.

4-         anterior debridement and strut graft, with possible posterior instrumentation.

5-         posterior extracavitary decompression alone.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Indications for surgery in spinal infections include progressive destruction despite antibiotic treatment, an abscess requiring drainage, neurologic deficit, need for diagnosis, and/or instability.  This patient has a progressive neurologic deficit.  Debridement performed at the site of the abscess should effect canal decompression. Once the debridement is complete back to viable bone, the defect can be reconstructed with a strut graft.  Additional posterior stabilization is used as deemed necessary by the degree of anterior destruction.  CT-guided needle aspiration, while occasionally useful in the earliest phases of an infection, produces frequent false-negative results and would provide little useful information in the management of this patient. 

 

REFERENCES: Emery SE, Chan DP, Woodward HR: Treatment of hematogenous pyogenic vertebral osteomyelitis with anterior debridement and primary bone grafting.  Spine 1989;14:284-291.

Lifeso RM: Pyogenic spinal sepsis in adults.  Spine 1990;15:1265-1271.

Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 713-721.

 

 

 

 

18.       A 21-year-old woman with Marfan syndrome is seeking evaluation of her scoliosis.  She reports no back or leg pain, and the neurologic examination is normal.  Lateral and bending radiographs are shown in Figures 7a through 7e.  Management should consist of

 

1-         observation and regular follow-up.

2-         a custom-molded thoracolumbar orthosis.

3-         anterior spinal fusion from T10 to L4.

4-         anterior and posterior spinal fusion from T10 to L4.

5-         posterior spinal fusion from T4 to L4.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Because the patient’s thoracolumbar scoliosis is of a large enough magnitude, observation or bracing is not recommended.  The thoracolumbar curve is flexible enough and L4 corrects well enough to the pelvis to consider anterior spinal fusion from T10 to L4.

 

REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 161-171.

Turi M, Johnston CE II, Richards BS: Anterior correction of idiopathic scoliosis using TSRH instrumentation.  Spine 1993;18:417-422.

Moskowitz A, Trommanhauser S: Surgical and clinical results of scoliosis surgery using Zielke instrumentation.  Spine 1993;18:2444-2451.

 

 

 

 

19.       Which of the following substances is least likely to affect the success of bone union after lumbar arthrodesis?

 

1-         Ketorolac

2-         Indomethacin

3-         Oxycodone hydrochloride

4-         Ibuprofen

5-         Nicotine

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Much attention has been given to the use of supplemental postoperative analgesia with nonsteroidal anti-inflammatory drugs (NSAIDs), and a significant reduction in narcotic use has been recorded.  However, a high failure rate of arthrodesis has been associated with the use of postoperative NSAIDs.  Glassman and associates reported 29 cases of pseudarthrosis in 167 patients when ketorolac was used as a postoperative analgesic, whereas only five fusion failures were noted in 121 patients not using ketorolac.  Indomethacin and ibuprofen have been shown to adversely affect bone formation in clinical and animal trials.  Nicotine has also been shown in a number of studies to decrease the fusion rate.  Oxycodone hydrochloride is a synthetic morphine and does not affect the fusion process.

 

REFERENCES: Glassman SD, Rose SM, Dimar JR, Puno RM, Campbell MJ, Johnson JR: The effect of postoperative nonsteroidal anti-inflammatory drug administration on spinal fusion.  Spine 1998;23:834-838.

Deguchi M, Rapoff AJ, Zdeblick TA: Posterolateral fusion for isthmic spondylolisthesis in adults: Analysis of fusion rate and clinical results.  J Spinal Disord 1998;11:459-464.

Dimar JR II, Ante WA, Zhang YP, Glassman SD: The effect of nonsteroidal anti-inflammatory drugs on posterior spinal fusions in the rat.  Spine 1996;21:1870-1876.

 

 

 

 

20.       A 33-year-old woman sustains a C6 burst fracture diving into a swimming pool, resulting in a complete spinal cord injury.  The canal compromise is shown in Figures 8a and 8b.  Functional recovery would be maximized with

 

1-         anterior corpectomy followed by strut grafting and instrumentation.

2-         halo vest immobilization.

3-         laminectomy and posterior wiring.

4-         laminectomy followed by halo vest immobilization.

5-         posterior lateral mass plating and fusion.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Although the patient has sustained a complete spinal cord injury, an anterior decompression, even performed late, can gain an additional level of root function.  In the quadriplegic patient, this can mean the difference between dependent and independent function.  Posterior procedures do not afford adequate access to the retropulsed bony fragments compromising the canal.

 

REFERENCES: Bohlman HH, Anderson PA: Anterior decompression and arthrodesis of the cervical spine: Long-term motor improvement.  Part I: Improvement in incomplete traumatic quadriparesis.  J Bone Joint Surg Am 1992;74:671-682.

Benz R, Abitbol JJ, Ozanne S, Garfin SR: Cervical burst fractures, in Levine AM, Eismont FJ, Garfin SR, Zigler JE (eds): Spine Trauma.  Philadelphia, PA, WB Saunders, 1998, pp 300-330.

 

 

 

 

21.       In the upright standing position, approximately what percent of the vertical load is borne by the lumbar spine facet joints?

 

1-         0%

2-         20%

3-         40%

4-         60%

5-         80%

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Direct measurement and finite element modeling results show that
approximately 20% of the vertical load is borne by the posterior structures of the lumbar
spine in the upright position.

 

REFERENCES: Adams MA, Hutton WC: The effect of posture on the role of the apophyseal joints in resisting intervertebral compressive forces.  J Bone Joint Surg Br 1980;62:358-362.

Goel VK, Kong W, Han JS, Weinstein JN, Gilbertson LG: A combined finite element and optimization investigation of lumbar spine mechanics with and without muscles.  Spine 1993;18:1531-1541.

 

 

 

 

22.       A 40-year-old patient who has a type II odontoid fracture is placed in  a halo vest for 12 weeks; however, current radiographs show no evidence of healing.  The next most appropriate step in management should consist of

 

1-         removal of the halo vest, followed by observation if the patient remains asymptomatic.

2-         use of the halo vest for an additional 4 weeks, followed by repeat radiographs.

3-         placement of one odontoid screw and the addition of bone graft.

4-         placement of two odontoid screws.

5-         posterior fusion at C1-2.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Because nonsurgical managment has failed and a significant number of type II odontoid fractures will go on to a nonunion, the salvage treatment of choice is posterior fusion at C1-2.  Odontoid screws are contraindicated in patients with a chronic nonunion, which this patient has at the end of 3 months.

REFERENCES: Montesano PX: Anterior and posterior screw and plate techniques used in the cervical spine, in Bridwell KH, DeWald RL (eds): The Textbook of Spinal Surgery, ed 2.  Philadelphia, PA, Lippincott-Raven, 1996, vol 2, pp 1743-1761.

Bohler J: Anterior stabilization for acute fractures and non-unions of the dens.  J Bone Joint Surg Am 1982;64:18-27.

Anderson PA, Steinmann JC: Internal fixation of the cervical spine, in Frymoyer JW (ed): The Adult Spine, Principles and Practice, ed 2.  Philadelphia, PA, Lippincott Raven, 1997, pp 1119-1147.

 

 

 

 

23.       In the initial evaluation of acute low back pain (duration of less than 4 weeks), plain radiographs are recommended in which of the following situations?

 

1-         Prolonged use of steroids

2-         Prolonged use of nonsteroidal anti-inflammatory drugs

3-         History of back pain as a child

4-         Family history of back pain

5-         Recent viral infection

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Prolonged use of steroids is associated with compression fractures with minimal trauma. Indications for radiography with acute low back pain include possible tumor, fracture, infection, or cauda equina syndrome.

 

REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, Appendix A15.

Helfgott SM: Sensible approach to low back pain.  Bull Rheum Dis 2001;3:50.

 

 

 

 

24.       Figure 9 shows a cross-sectional view of the spinal cord at the lower cervical level.  Injury to the structure indicated by the black arrow will lead to what neurologic deficit?

 

1-         Complete paraplegia

2-         Contralateral weakness below the level of the injury

3-         Ipsilateral weakness below the level of the injury

4-         Unilateral loss of position sense, proprioception, and vibratory sense below the level of the injury

5-         Loss of pain and temperature sensation below the level of the injury

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The arrow is pointing to the posterior columns of the spinal cord that transmit position sense, vibratory sense, and proprioception. There are no motor tracts in the posterior columns.

 

REFERENCES: Bohlman H, Ducker T, Levine A: Spine trauma in adults, in Herkowitz HH (ed): The Spine, ed 4.  Philadelphia, PA, WB Saunders, 1992, p 911.

Northrup B: Evaluation and early treatment of acute injuries to the spine and spinal cord, in Clark CR (ed): The Cervical Spine, ed 3.  Philadelphia, PA, Lippincott Raven, 1998, p 545.

 

 

 

 

25.       A 26-year-old woman who noted right-sided lumbosacral pain 10 days ago while vacuuming now reports that the pain has intensified.  She denies any history of back problems.  No radicular component is present, and her neurologic examination is normal.  The next most appropriate step in management should consist of

 

1-         a brief (2 to 3 days) period of bed rest and nonsteroidal anti-inflammatory drugs.

2-         bed rest for 2 weeks and nonsteroidal anti-inflamatory drugs, followed by physical therapy.

3-         epidural steroid injections.

4-         lumbar radiographs and MRI of the lumbar spine.

5-         electromyography.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The initial management of a lumbar strain should consist of 2 to 3 days of bed rest when symptoms are severe, activity restrictions, and nonsteroidal anti-inflammatory drugs.  It has been estimated that 60% to 80% of the adult population experiences back pain, with 2% to 5% affected yearly.  Spontaneous improvement generally will occur within 4 weeks.  Further study is indicated by the presence of radiculopathy, weakness, trauma, or suspicion of malignancy.

 

REFERENCES: Bigos S, Boyer O, Braen GR, et al: Acute low back pain in adults: Clinical practice guideline No. 14. AHCPR Publication No. 95-0642. Rockville, MD, Agency for Health Care Policy and Research, Public Health Service, US Department of Health and Human Services, December, 1994.

Deyo RA: Conservative therapy for low back pain: Distinguishing useful from useless therapy. JAMA 1983;250:1057-1062.

 

 

 

26.       A patient with myelopathy underwent a one-level corpectomy 1 day ago and is now home.  In the middle of the night he calls to report markedly increased difficulty in swallowing, diaphoresis, a change in his voice, and difficulty lying flat.  What is the best course of action?

 

1-         Reassure the patient that the symptoms should subside gradually and that he should remain as upright as possible and loosen his cervical collar.

2-         Prescribe methylprednisolone and diazepam.

3-         Admit the patient for observation.

4-         Advise the patient to come to the office first thing in the morning for a lateral radiograph of the cervical spine.

5-         Advise immediate transport to the emergency department for evaluation of the airway, possible intubation, and possible cricothyroidotomy.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The patient has respiratory distress as manifested by his difficulty in lying flat.  In addition, the diaphoresis and the change in his voice indicate retropharyngeal edema or hematoma that is compressing his larynx.  The only appropriate treatment is hospital admission and elective intubation.  During intubation it is possible to cause laryngospasm in a patient with a hyperacute airway; therefore, the surgeon should be prepared to perform a cricothyroidotomy.  Often a fiberoptically guided intubation is the only way to find the airway in the presence of retropharyngeal edema or hematoma.

 

REFERENCES: Emery SE, Smith MD, Bohlman HH: Upper-airway obstruction after multilevel cervical corpectomy for myelopathy.  J Bone Joint Surg Am 1991;73:544-551. 

McAfee PC, Bohlman HH, Riley LH Jr, Robinson RA, Southwick WO, Nachlas NE: The anterior retropharyngeal approach to the upper part of the cervical spine.  J Bone Joint Surg Am 1987;69:1371-1383.

 

 

 

 

27.       Figure 10 shows the radiograph of an 18-year-old woman who sustained a spinal cord injury in a motor vehicle accident.  Based on the radiographic findings, her injury is best described as

 

1-         distractive extension.

2-         compressive extension.

3-         lateral flexion.

4-         distractive flexion.

5-         compressive flexion.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The Allen and Ferguson mechanistic classification system is a useful tool for evaluating cervical spine injuries.  Cervical fractures are classified as compressive extension, distractive extension, compressive flexion, distractive flexion, vertical compression, and lateral flexion.  The patient has a distractive flexion injury.

 

REFERENCE: Allen BL Jr, Ferguson RL, Lehmann TR, O’Brien RP: A mechanistic classification of closed, indirect fractures and dislocations of the lower cervical spine.  Spine 1982;7:1-27.

 

 

 

 

28.       Examination of a 30-year-old professional singer who has persistent neck and shoulder pain reveals a positive Hoffman’s sign and clonus because of anterior C2-3 cord compression.  The MRI scan shown in Figure 11a and the cervical CT scan shown in Figure 11b reveal focal anterior cord compression at the C2-3 level.  Which of the following surgical approaches would least affect her professional career?

 

1-         Transoral, transmucosal direct anterior approach to C2-3

2-         Left-sided anterior approach to C2-3 (Smith-Robinson)

3-         Right-sided posterior retropharyngeal approach to C2-3 (Whitesides)

4-         Right-sided anterior approach to C2-3 (Smith-Robinson)

5-         Right-sided anterior retropharyngeal approach with extended vertical incision (superior extension Smith-Robinson)

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Protection of the superior laryngeal nerve is critical in a professional singer.  The nerve is easily injured with retraction when using vertical extension of common anterior surgical approaches to gain exposure to the C2-3 level.  McAfee and associates reported on 17 patients with C1-2 and C2-3 pathology.  They used a modified submandibular approach as an anterior retropharyngeal exposure with modification of the superior extension of the Smith-Robinson technique that allows visualization of the superior laryngeal nerve and surrounding structures.  No incidences of superior laryngeal nerve injury were recorded.  The transoral approach should be avoided because of the high rate of infection and limited exposure.

 

REFERENCES: McAfee PC, Bohlman HH, Reilly LH Jr, Robinson RA, Southwick WO, Nachlas NE: The anterior retropharyngeal approach to the upper part of the cervical spine.  J Bone Joint Surgery Am 1987;69:1371-1383.

Lu J, Ebraheim NA, Nadim Y, Huntoon M: Anterior approach to the cervical spine: Surgical anatomy.  Orthopedics 2000;23:841-845.

 

 

 

 

29.       Figure 12 shows the lumbar CT scan of a 24-year-old man who was injured in a snowmobile accident.  What is the mechanism of injury?

 

1-         Flexion extension

2-         Flexion distraction

3-         Vertical compression

4-         Extension compression

5-         Extension distraction

 

PREFERRED RESPONSE: 3

 

DISCUSSION: A true compression fracture is a single-column injury that does not create canal compromise.  A burst fracture is a two- or three-column injury that disrupts the middle column and thereby narrows the spinal canal.  This patient has a burst fracture.  The mechanism of injury is usually vertical compression or flexion compression.

 

REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 197-217.

Spivak JM, Vaccaro AR, Cotler JM: Thoracolumbar spine trauma: Principles of management.  J Am Acad Orthop Surg 1995;3:353-360.

 

 

 

 

30.       Which of the following changes occur in the spinal cord and the spinal canal when the cervical spine moves from neutral to full flexion?

 

1-         The spinal cord relaxes and the spinal canal shortens.

2-         The spinal cord undergoes elastic deformation and the spinal canal lengthens.

3-         The spinal cord remains unchanged and the spinal canal lengthens.

4-         The spinal cord remains unchanged and the spinal canal shortens.

5-         Neither structure shows any predictable pattern of changes.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The spinal cord and spinal canal undergo dynamic changes during neck flexion and extension.  In neck flexion, the spinal cord initially unfolds and then undergoes elastic deformation with full flexion; the spinal canal lengthens.  This may explain the presence of Lhermitte’s sign as the cord is pulled anteriorly over an anterior osteophyte or disk, generating a compressive force on the spinal cord.  During neck extension, the spinal cord relaxes (folding like an accordion) and the spinal canal shortens.

 

REFERENCES: Breig A: Biomechanics of the Central Nervous System: Some Basic Normal and Pathologic Phenomena.  Stockholm, Sweden, Almquist and Wiksell, 1960.

Ghanayem AJ, Zdeblick TA, Panjabi MM: Biomechanics of nonacute cervical spine trauma, in Clark CR (ed): The Cervical Spine, ed 3.  Philadelphia, PA, Lippincott Raven, 1998, pp 103-105.

 

 

 

 

31.       A patient who was involved in a motor vehicle accident 2 days ago now reports neck pain.  He denies any other symptoms.  Radiographs reveal a type II odontoid fracture that is 2 mm anteriorly displaced.  Management consists of halo vest immobilization in extension, and repeat radiographs reveal that the fracture is completely reduced.  The patient is discharged to home, but later that evening he notes difficulty swallowing while trying to eat dinner.  What is the most likely cause of this difficulty?

 

1-         Injury to the recurrent laryngeal nerve

2-         Injury to the superior laryngeal nerve

3-         Esophageal trauma at the time of the fracture or at the time of the reduction

4-         Retropharyngeal edema or hematoma from the fracture

5-         Halo vest placement

 

PREFERRED RESPONSE: 5

 

DISCUSSION: If the neck is immobilized in excessive extension, it can be difficult for the patient to swallow.  If the patient had injured the recurrent or superior laryngeal nerve at the time of the accident, it is likely to have manifested itself earlier on.  Esophageal trauma or retropharyngeal edema or hematoma from the fracture also should have manifested itself earlier.  Because the fracture was completely reduced, it is unlikely that moving the small fragment posteriorly would have injured the esophagus.

 

REFERENCES: Garfin SR, Botte MJ, Waters RL, Nickel VL: Complications in the use of halo fixation device.  J Bone Joint Surg Am 1986;68:320-325.

Glaser JA, Whitehill R, Stamp WG, Jane JA: Complications associated with the halo-vest: A review of 245 cases.  J Neurosurg 1986;65:762-769.

 

 

 

 

32.       A 64-year-old man who underwent an L4-5 decompression approximately 1 year ago reported relief of his claudicatory leg pain initially, but he now has increasing low back pain and recurrent neurogenic claudication despite nonsurgical management.  Radiographs show new asymmetric collapse and spondylolisthesis at the decompressed segment, and MRI scans show lateral recess stenosis.  The next most appropriate step in management should consist of

 

1-         L4-5 diskectomy.

2-         L4-5 diskectomy and lateral recess decompression.

3-         revision posterior decompression.

4-         revision posterior decompression and posterolateral fusion.

5-         anterior lumbar interbody fusion with cages.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: When radiographic findings reveal postlaminectomy instability, procedures that do not include some type of fusion will fail to solve the problem.  In fact, wider decompression or diskectomy alone will only further destabilize the segment.  Because there is radiographic evidence of recurrent lateral recess stenosis and symptomatic neurogenic claudication, a revision decompression should be included.  Since access to the canal involves a posterior approach, the stabilization should be performed through that same approach.

 

REFERENCES: Herkowitz HN, Kurz LT: Degenerative lumbar spondylolisthesis with spinal stenosis: A prospective study comparing decompression with decompression and intertransverse process arthrodesis.  J Bone Joint Surg Am 1991;73:802-808.

Hansraj KK, O’Leary PF, Cammisa FP Jr, et al: Decompression, fusion, and instrumentation surgery for complex lumbar spinal stenosis.  Clin Orthop 2001;384:18-25.

 

 

 

 

33.       A patient who was involved in a motor vehicle accident 2 weeks ago now reports neck pain. Work-up reveals no evidence of nerve root involvement or acute radiographic abnormality. The patient appears to have a hyperextension soft-tissue injury of the neck (whiplash). What is the best course of treatment at this time?

 

1-         No immobilization, no time off from work, and instructions to go about normal activities

2-         Part-time soft collar immobilization and modified duty at work for 1 to 2 weeks

3-         Full-time soft collar immobilization and modified duty at work for 1 to 2 weeks

4-         Full-time rigid collar immobilization and time off from work for 1 to 2 weeks

5-         Repeat MRI to assess for occult disk or ligamentous injury

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Early mobilization and resumption of normal activities immediately after neck sprain has been shown to improve functional outcome and decrease subjective symptoms as measured 6 months after injury.

 

REFERENCES: Borchgrevink GE, Kaasa A, McDonagh D, Stiles TC, Haraldseth O, Lereim I: Acute treatment of whiplash neck injuries: A randomized trial during the first 14 days after a car accident.  Spine 1998;23:25-31.

Mealy K, Brennan H, Fenelon GC: Early mobilization of acute whiplash injuries.  Br Med J 1986;292:656-657.

 

 

 

 

34.       A 19-year-old man has had back pain with activity, especially running in soccer and baseball, for the past 4 months.  He denies any history of trauma.  Examination reveals no motor weakness or sensory changes in the lower extremities.  Range of motion shows increased pain with extension and mild limitation with flexion.  A sitting straight leg raising test is limited at approximately 60 degrees bilaterally by back and buttocks pain.  Plain radiographs are normal.  MRI scans are shown in Figures 13a through 13e.  What is the most likely diagnosis?

 

1-         Isthmic spondylolysis

2-         Herniated nucleus pulposus at L5-S1

3-         Lumbar sprain

4-         Limbus fracture

5-         Aseptic diskitis

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The patient has an isthmic spondylolysis.  The plain radiographs are normal, but the MRI scans show increased marrow edema and signal at the L5 pars interarticularis.  Findings of bilateral hamstring tightness and increased pain with extension over flexion suggests spondylolysis.  The MRI scans do not show any signs of the other conditions.

 

REFERENCES: Wiltse LL, Rothman SL: Spondylolisthesis: Classification, diagnosis and natural history.  Sem Spine Surg 1993;5:264-280.

Richards BS (ed): Orthopaedic Knowledge Update: Pediatrics.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1996, pp 129-137.

 

 

 

 

35.       A neurologic injury at T11-L2 with loss of bowel and bladder control is best described as what syndrome?

 

1-         Anterior cord

2-         Central cord

3-         Posterior cord

4-         Conus medullaris

5-         Cauda equina

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Conus medullaris syndrome describes isolated loss of bowel and bladder function, usually at T12-L1 but can include T11-L2.  In central cord syndrome, lower extremity motor function is better than upper extremity function.  Cauda equina syndrome generally involves injury at the lumbar levels, with some degree of lower extremity motor loss.  Posterior cord syndrome is characterized by preservation of motor function below the level of injury and position/vibratory sensory loss.  In anterior cord syndrome, the lower extremity findings include loss of light touch, sharp/dull, and temperature sensations below the level of injury, as well as motor function.

 

REFERENCES: Apple DF Jr: Spinal cord injury rehabilitation, in Rothman RH, Simeone FA (eds): The Spine, ed 3.  Philadelphia, PA, WB Saunders, 1992, Chapter 31.

Weisberg LA: Neurologic localization: Lesions below foramen magnum, in Weisberg LA, Strub RL, Garcia CA (eds): Adult Neurology, ed 2.  St. Louis, MO, Mosby, 1993.

 

 

 

36.       The space available for the cord is an important determinant in neurologic recovery.  Recent analysis suggests that the most reliable radiographic predictor for neurologic recovery after surgery in patients with rheumatoid arthritis and paralysis is a preoperative

 

1-         anterior alanto-odontoid interval of less than 9 mm.

2-         anterior alanto-odontoid interval of greater than 9 mm.

3-         posterior alanto-odontoid interval of greater than 10 mm.

4-         posterior alanto-odontoid interval of greater than 12 mm.

5-         posterior alanto-odontoid interval of greater than 14 mm.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Boden and associates’ recent article presents significant evidence that patients with rheumatoid arthritis, neurologic deterioration, and C1-2 instability are more likely to improve after surgery if the posterior alanto-odontoid interval is greater than 10 mm preoperatively.  The accepted safe range for the posterior atlanto-odontoid interval is 14 mm.  This measurement is believed to better represent the space available for the cord than the anterior alanto-odontoid interval.

 

REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 273-279.

Boden SD, Dodge LD, Bohlman HH, Rechtine GR: Rheumatoid arthritis of the cervical spine: A long-term analysis with predictors of paralysis and recovery.  J Bone Joint Surg Am 1993;75:1282-1297.

Wattenmaker I, Concepcion M, Hibberd P, Lipson S: Upper airway obstruction and perioperative management of the airway in patients managed with posterior operations on the cervical spine for rheumatoid arthritis.  J Bone Joint Surg Am 1994;76:360-365.

 

 

 

37.       A 21-year-old woman with scoliosis reports no pain, and her examination is unremarkable except for the scoliosis.  Preoperative radiographs, including bending views, are shown in Figures 14a through 14e.  The thoracic curve measures 62 degrees.  Treatment should consist of

 

1-         posterior fusion from T2 to L3.

2-         posterior fusion from T4 to L1.

3-         posterior fusion from T4 to L4.

4-         anterior fusion from T6 to L1.

5-         anterior fusion from T9 to T11.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The patient has a King type III curve with a very flexible lumbar spine that derotates and levels well on side bending.  The fractional upper thoracic curve is also quite flexible and will not need to be addressed; therefore, treatment should consist of posterior spinal fusion from T4 to L1.  An anterior spinal fusion at the very apex of the curve will not address the curve satisfactorily, and an approach across the diaphragm provides little benefit in this patient.

 

REFERENCES: King HA, Moe JH, Bradford DS, Winter RB: The selection of fusion levels in thoracic idiopathic scoliosis.  J Bone Joint Surg Am 1983;65:1302-1313.

Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 161-171.

 

 

 

 

38.       Figure 15 shows possible locations of anterior pin sites for halo fixation.  What location is considered most ideal?

 

1-         A

2-         B

3-         C

4-         D

5-         E

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The anterior pin should be placed just above and lateral to the eyebrow at the site labeled A.  At site B, the supraorbital nerve can be damaged.  At site C, the supratrochlear nerve or the frontal sinus can be damaged.  The site labeled D is over the temporalis muscle; in this location the temple bone is thin and there is the risk of perforation.  Site E is above the equator of the forehead; at this location there is a risk that the halo ring will slip off the head altogether.

 

REFERENCES: Garfin SR, Botte MJ, Waters RL, Nickel VL: Complications in the use of halo fixation device.  J Bone Joint Surg Am 1986;68:320-325.

Garfin SR, Botte MJ, Centeno RS, Nickel VL: Osteology of the skull as it affects halo pin placement.  Spine 1985;10:696-698.

 

 

 

 

39.       A 30-year-old man requires surgical stabilization of a hypermobile spondylolisthesis of L5 on S1.  History reveals that he has smoked one pack of cigarettes a day for 15 years.  During preoperative counseling, the patient should be advised to

 

1-         stop smoking immediately preoperatively and for at least 6 months postoperatively.

2-         stop smoking at least 3 months preoperatively and for 6 months postoperatively with the assistance of nicotine patches or gum.

3-         stop smoking postoperatively with the assistance of nicotine patches or gum.

4-         delay surgery to allow the patient to stop smoking for at least 6 months prior to surgery and for 6 months postoperatively.

5-         consider a different treatment because the rate of pseudarthrosis and clinical failure following fusion is unacceptable in smokers.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Many studies have shown the negative effects of cigarette smoking on the success of lumbar arthrodesis.  Some have suggested preoperative cessation is a significant factor for good results.  However, Deguchi and associates, in a review of spondylolisthesis fusions, and Glassman and associates, in a review of scoliosis fusions, showed no significant benefit from preoperative cessation of smoking.  In every report, however, postoperative smoking correlated with a significantly increased rate of pseudarthrosis.  Cessation of smoking with the use of nicotine substitutes would not be beneficial because animal studies and human clinical trials have shown that nicotine is a major factor in failure of fusion in patients who continue to smoke.

 

REFERENCES: Silcox DH III, Daftari T, Boden SD, Schimandle JH, Hutton WC, Whitesides TE Jr: The effect of nicotine on spinal fusion.  Spine 1995;20:1549-1553.

Deguchi M, Rapoff AJ, Zdeblick TA: Posterolateral fusion for isthmic spondylolisthesis in adults: Analysis of fusion rate and clinical results.  J Spinal Disord 1998;11:459-464.

Glassman SD, Anagnost SC, Parker A, Burke D, Johnson JR, Dimar JR: The effect of cigarette smoking and smoking cessation on spinal fusion.  Spine 2000;25:2608-2615.

 

 

 

 

40.       What is the most likely type of pathology seen in Figure 16?

 

1-         Tumor

2-         Infection

3-         Inflammatory

4-         Congenital

5-         Trauma

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The figure shows the missing pedicle or “winking owl” sign that is characteristic of tumor involvement of the cortical bone of the pedicle.  None of the other pathologic processes commonly gives this radiographic picture.  Thinned, but not missing pedicles, have been described as a normal variant.

 

REFERENCES: McLain R, Weinstein J: Tumors of the spine, in Herkowitz HH (ed): The Spine, ed 4.  Philadelphia, PA, WB Saunders, 1992, p 1173.

Charlton OP, Martinez S, Gehweiler JA Jr: Pedicle thinning at the thoracolumbar junction: A normal variant.  Am J Roentgenol 1980;134:825-826.

 

 

 

 

41.       In a retroperitoneal approach to the lumbar spine, what nerve is commonly found on the psoas muscle?

 

1-         Ilioinguinal

2-         Iliohypogastric

3-         Genitofemoral

4-         Obturator

5-         Femoral

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The genitofemoral nerve and the sympathetic plexus consistently lie on the ventral surface of the psoas muscle. The ilioinguinal and iliohypogastric nerves are the most superior branches of the lumbar plexus and emerge along the upper lateral border of the psoas muscle traveling toward the quadratus lumborum. Both the obturator and femoral nerves are deep and lateral to the psoas muscle.

 

REFERENCES: Watkins RG (ed): Surgical Approaches to the Spine, ed 1.  New York, NY,  Springer-Verlag, 1983, p 107.

Johnson R, Murphy M, Southwick W: Surgical approaches to the spine, in Herkowitz HH (ed): The Spine, ed 4.  Philadelphia, PA, WB Saunders, 1992, p 1559.

Gray’s Anatomy. New York, NY, Bounty Books, 1977, pp 1226-1227.

 

 

 

 

42.       A 21-year-old man has had posterior neck discomfort for the past 6 months.  Radiographs, an MRI scan, and a photomicrograph of the biopsy specimen are shown in Figures 17a through 17d.  What is the most likely diagnosis?

 

1-         Fibrous dysplasia

2-         Osteochondroma

3-         Osteoblastoma

4-         Giant cell tumor

5-         Hemangioma

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Forty percent of osteoblastomas occur in the spine, and they can become large and locally aggressive lesions.  They generally occur in the posterior elements but can occur in the ribs and transverse processes.  Microscopic analysis of the lesion will reveal hyperchromatic osteoblasts separated by incompletely mineralized bars of bone.  Recommended treatment is en bloc excision.  Fibrous dysplasia, giant cell tumor, and hemangioma can have similar radiographic appearances; therefore, biopsy may be required to differentiate them from more aggressive lesions.  Osteochondromas are characterized by an osteocartilaginous growth arising from the cortex.

 

REFERENCES: Bridwell KH, Ogilvie JW: Primary tumors of the spine, in Bridwell KH, DeWald RL (eds): The Textbook of Spinal Surgery.  Philadelphia, PA, JB Lippincott, 1991,
vol 2, pp 1143-1174.

Enneking WF: Musculoskeletal Tumor Surgery.  New York, NY, Churchill Livingstone, 1983, pp 1043-1053.

 

 

 

 

43.       An otherwise healthy 16-year-old boy who has had thoracolumbar pain with an increasingly worse deformity for the past 2 years now reports that the pain is worse at night.  He responded well to nonsteroidal anti-inflammatory drugs initially, but they have become less effective.  He denies any neurologic or constitutional symptoms.  Examination is consistent with a mild thoracolumbar scoliosis and is otherwise normal.  Laboratory studies show a normal CBC, erythrocyte sedimentation rate, and C-reactive protein.  Standing radiographs show a 20 degrees left thoracolumbar scoliosis, and he has a Risser stage of 4.  A bone scan shows increased uptake at L2; a CT scan through this level is shown in Figure 18.  Management should now consist of

 

1-         percutaneous aspiration and appropriate antibiotic therapy.

2-         an underarm Boston brace for 23 hours per day.

3-         a referral for radiation therapy.

4-         posterior instrumented arthrodesis from one level above to one level below the deformity.

5-         removal of the lesion and local arthrodesis if necessary.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The findings and radiographic appearance are most consistent with osteoid osteoma involving the medial pedicle.  Scoliosis is commonly seen with this lesion and usually does not need surgical intervention.  Excellent results have been reported with surgical excision as well as with percutaneous thermocoagulation.  Nonsurgical treatment also has been described in peripheral osteoid osteoma but is not well described for lesions within the spine.

 

REFERENCES: Cove JA, Taminiau AH, Obermann WR, Vanderschueren GM: Osteoid osteoma of the spine treated with percutaneous computed tomography-guided thermocoagulation.  Spine 2000;25:1283-1286.

Kneisl JS, Simon MA: Medical management compared with operative treatment for osteoid-osteoma.  J Bone Joint Surg Am 1992;74:179-185.

Pettine KA, Klassen RA: Osteoid-osteoma and osteoblastoma of the spine.  J Bone Joint Surg Am 1986;68:354-361.

 

 

 

 

44.       Which of the following assessment tools most accurately reflects outcomes of well-being, daily function, and general health in a patient treated for cervical myelopathy?

 

1-         Short-form 36

2-         Japanese Orthopaedic Association score

3-         Nurick criteria

4-         Odom criteria

5-         Neck disability index

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The short-form 36 is an excellent tool for measuring the patient’s perception of treatment outcome because it is a patient-generated, validated assessment of physical, social, and role function, emotional and mental health, energy/fatigue, pain, health perception, and health change.  The Nurick criteria is an evaluation of physical function with gradations of ambulation and daily function.  The Japanese Orthopaedic Association score gives points for function in activities of daily living but does not assess perception of general health.  The neck disability index assesses the impact of neck pain on daily life, and the Odom criteria are the surgeon’s evaluations of degree of radicular pain and deficit.

 

REFERENCES: Albert TJ, Mesa JJ, Eng K, McIntosh TC, Balderston RA: Health outcome assessment before and after lumbar laminectomy for radiculopathy.  Spine 1996;21:960-963.

Swiontkowski MF, Buckwalter JA, Keller RB, Haralson R: The outcomes movement in orthopaedic surgery: Where we are and where we should go.  J Bone Joint Surgery Am 1999;81:732-740.

Ludwig SC, Albert TJ: Measuring outcomes in cervical myelopathy and radiculopathy. 
Instr Course Lect 1999;48:417-421.

 

 

 

 

45.       A 54-year-old man undergoes uneventful anterior cervical diskectomy and interbody fusion at C4-5 for focal disk herniation and C5 radiculopathy.  At the 3-week follow-up examination, the patient reports a persistent cough.  Pulmonary evaluation reveals a mild but persistent aspiration.  Laryngoscopy reveals partial paralysis of the left vocal cord, most likely caused by

 

1-         entrapment of the superior laryngeal nerve during ligation of the superior thyroid artery.

2-         stretch of the recurrent laryngeal as it enters the esophageal-tracheal groove.

3-         injury to the vocal cord during endotracheal intubation.

4-         displacement of the larynx against the endotracheal tube by retraction.

5-         retractor pressure on the laryngeal nerve in the esophageal groove.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The exact anatomic event responsible for vocal cord paralysis associated with anterior cervical surgery remains a question.  Apfelbaum and associates, in an excellent review of 900 anterior cervical surgeries, identified 30 patients with vocal cord paralysis, 3 of which were permanent.  They showed that retractors placed under the longus coli for anterior cervical exposures can compress the laryngeal-tracheal branches within the larynx against the tented endotracheal tube rather than the recurrent laryngeal nerve, which is extrinsic to the larynx.  By releasing the endotracheal cuff and allowing the tube to recenter itself after placement of the retractors, they were able to decrease vocal cord injury from 6.4% to 1.7%.  Jewett and associates suggested that a left-sided approach may result in a lower incidence of injury.  Endotracheal intubation is the second most common cause of vocal cord injury, with an incidence of approximately 2%.

 

REFERENCES: Apfelbaum RI, Kriskovich MD, Haller JR: On the incidence, cause, and prevention of recurrent laryngeal nerve paralysis during anterior cervical spine surgery.  Spine 2000;25:2906-2912.

Jewett BA, Menico GA, Spengler DM, Coleman SC, Netterville JL: Vocal Cord Paralysis Following Anterior Cervical Spine Surgery.  Paper presented at the annual meeting or the Cervical Spine Research Society, December 2000, Charleston SC, Paper #7.

 

 

 

46.       A 32-year-old professional football player has disabling left arm pain in the C7 dermatome that has been increasing in severity for the past 2 months.  Examination shows a positive Spurling test on the left side, but no changes in motor, sensory, or deep tendon reflexes.  Because nonsurgical management has failed to provide relief, he has chosen surgery to allow him to complete his season.  The MRI scan and myelogram shown in Figures 19a and 19b show minimal disk bulge, but a root cutoff is noted at the left C7 foramen.  Electromyography demonstrates C7 nerve root irritation.  Which of the following procedures will best optimize his chances for completing the season?

 

1-         Posterior keyhole foraminotomy on the left side at C6-7

2-         Posterior laminoplasty at C6-7

3-         Posterior laminectomy at C6 and C7 and bilateral foraminotomies at C6-7

4-         Anterior diskectomy and interbody fusion at C6-7

5-         Anterior limited diskectomy and foraminotomy without fusion

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Because the patient has chronic pain, a possible lateral recess stenosis of the C7 root, and no neurologic deficits, keyhole foraminotomy is the treatment of choice for decompressing the exiting nerve root and offering an early return to play, especially when using a muscle-splitting posterior approach.  Henderson and associates reported excellent results with posterolateral foraminotomy in patients with radicular symptoms.  Although anterior cervical diskectomy and fusion is equally effective in the long term, a period of 6 to 12 weeks is required to allow the anterior fusion to heal prior to a return to play.  Chen and associates reported that keyhole foraminotomy maintains cervical motion segment dynamics better than compared to anterior limited diskectomy and foraminotomy or anterior diskectomy with fusion.

 

REFERENCES: Henderson, CM, Hennessy RG, Shuey HM Jr, Shackelford EG: Posterior-lateral foraminotomy as an exclusive operative technique for cervical radiculopathy: A review of 846 consecutively operated cases.  Neurosurgery 1983;13:504-512.

Dillin W, Booth R, Cuckler J, Balderston R, Simeone F, Rothman R: Cervical radiculopathy: A review.  Spine 1986;11:988-991.

Chen BH, Natarajan RN, An H, Andersson GB: Comparison of biomechanical response to surgical procedures used for cervical radiculopathy:  Posterior keyhole foraminotomy versus anterior foraminotomy and discectomy versus anterior discectomy with fusion.  J Spinal Disord 2001;14:17-20.

 

 

 

 

47.       The majority of severe cervical spine injuries occurring in contact sports evolve during axial loading and flexion of the cervical spine.  At what minimum degree of flexion does axial loading place the cervical spine at risk during contact sports?

 

1-         15 degrees

2-         30 degrees

3-         45 degrees

4-         60 degrees

5-         75 degrees

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The paravertebral musculature, the intervertebral disks, and the normal lordotic curvature of the cervical spine can absorb much of the imparted energy of collision.  However, when the neck is flexed approximately 30 degrees, the normal lordotic curvature is flattened and the forces applied to the vertex of the head are directed at a straight segmented column.  In this situation, the cervical spine is less able to absorb the applied force.  With mounting axial load, compressive deformation occurs within the intervertebral disks, causing angular deformation and buckling.  The spine will fail in flexion, with resultant fracture, subluxation, or dislocation.  A rotatory component added to axial compression can cause concomitant extension, rotation, and shear injury patterns.  The National Football Head and Neck Injury Registry has made two recommendations to the NCAA Football Rules Committee to minimize the risk of such injuries:  (1) No player should intentionally strike an opponent with the crown or top of the helmet; and (2) No player should deliberately use his helmet to butt or ram an opponent.

 

REFERENCES: Thomas BE, McCullen GM, Yuan HA: Cervical spine injuries in football players.  J Am Acad Orthop Surg 1999;7:338-347.

Torg JS, Truex R Jr, Quedenfeld TC, Burstein A, Spealman A, Nichols C III: The National Football Head and Neck Injury Registry: Report and conclusions 1978.  JAMA 1979;241:1477-1479.

 

 

 

 

48.       According to the Third National Acute Spinal Cord Injury Study (NASCIS 3), what is the recommended protocol for a patient who sustained a spinal cord injury 7 hours ago?

 

1-         Methylprednisolone 30 mg/kg initial bolus, followed by 5.4 mg/kg/h for 23 hours

2-         Methylprednisolone 30 mg/kg initial bolus, followed by 5.4 mg/kg/h for 48 hours

3-         Dexamethasone 10 mg bolus, followed by 6 mg every 6 hours for 24 hours

4-         Dexamethasone 10 mg bolus, followed by 6 mg every 6 hours for 48 hours

5-         No treatment

 

PREFERRED RESPONSE: 2

 

DISCUSSION: NASCIS 2 established the recommended doses of methylprednisolone for spinal cord injury.  This included an initial bolus of 30 mg/kg over 1 hour, followed by an infusion of 5.4 mg/kg/h for an additional 23 hours.  If the injury was more than 8 hours old, the methylprednisolone was not recommended.  NASCIS 3 changed the dosing schedule based on the time from injury.  If the time from injury to treatment was less than 3 hours, the standard protocol was followed (30 mg/kg bolus followed by 5.4 mg/kg/h for 23 hours).  If the time from injury to treatment was between 3 and 8 hours, the infusion was continued at 5.4 mg/kg for an additional 23 hours (48 hours total).  In this situation with a time of injury 7 hours ago, treatment should consist of a bolus and further steroid therapy for 48 hours.

 

REFERENCES: Bracken MB, Shepard MJ, Holford TR, et al: Administration of methylprednisolone for 24 or 48 hours or tirilazad mesylate for 48 hours in the treatment of acute spinal cord injury: Results of the Third National Acute Spinal Cord Injury Randomized Controlled Trial.  National Acute Spinal Cord Injury Study.  JAMA 1997;277:1597-1604.

Bracken MB, Shepard MJ, Collins WF, et al: A randomized, controlled trial of methylprednisolone or naloxone in the treatment of acute spinal-cord injury: Results of the Second National Acute Spinal Cord Injury Study.  N Engl J Med 1990;322:1405-1411.

 

 

 

 

49.       Lumbar instability may be surgically induced by

 

1-         removing the interspinous ligament and spinous process.

2-         removing the interspinous ligament and spinous process, followed by excessive debridement of the ligamentum flavum.

3-         removing the interspinous ligament, spinous process, and ligamentum flavum, and unilateral sacrifice of 35% of a medial facet.

4-         removing the interspinous ligament, spinous process, and ligamentum flavum, and bilateral sacrifice of 35% of the medial facets.

5-         unilateral facetectomy.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: In cadaveric studies, unilateral facetectomy, or excision of 50% or more of both facets, significantly decreases the biomechanic integrity of the motion segment and may increase the risk of iatrogenic instability.  Sacrifice of the spinous process, interspinous ligaments, and ligamentum flavum weakens the motion segment but does not increase the risk for instability.  Facetectomy, even unilateral, predisposes the patient toward lumbar instability.

 

REFERENCE: Abumi K, Panjabi MM, Kramer KM, Duranceau J, Oxland T, Crisco JJ: Biomechanical evaluation of lumbar spinal stability after graded facetectomies.  Spine 1990;15:1142-1147.

 

 

 

 

50.       A 19-year-old man who sustained a spinal cord injury in a motor vehicle accident 3 days ago has 5/5 full strength in the deltoids and biceps bilaterally, 4/5 strength in wrist extension bilaterally, 1/5 triceps function on the right side, and 2/5 triceps function on the left side.  The patient has no detectable lower extremity motor function.  Based on the American Spinal Injury Association’s classification, what is the patient’s functional level?

 

1-         C4

2-         C5

3-         C6

4-         C7

5-         C8

 

PREFERRED RESPONSE: 3

 

DISCUSSION: By convention when determining the motor level, the key muscle must be at least 3/5.  The next most rostral level must be 4/5.  Therefore, this patient’s functional level is C6.

 

REFERENCE: International Standards for Neurological and Functional Classification of Spinal Cord Injury.  Chicago, IL, American Spinal Injury Association Publication, 1996.

 

 

 

 

51.       What is the most common complication of halo vest immobilization in adults?

 

1-         Neurologic deterioration

2-         Pin loosening

3-         Pressure sores under the vest

4-         Psychosis

5-         Dural puncture

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Although pin loosening generally has not been considered a major problem, it has been cited as the most common complication in two published series of halo vest complications.  The other possible complications are all significantly less common.

 

REFERENCES: Baum JA, Hanley EN Jr, Pullekines J: Comparison of halo complications in adults and children.  Spine 1989;14:251-252.

Garfin SR, Botte MJ, Waters RL, Nickel VL: Complications in the use of the halo fixation device.  J Bone Joint Surg Am 1986;68:320-325.

Nemeth JA, Mattingly LG: Six-pin halo fixation and the resulting prevalence of pin-site complications.  J Bone Joint Surg Am 2001;83:377-382.

 

 

 

 

52.       What is the most common neurologic complication following an anterior cervical diskectomy and fusion?

 

1-         Spinal cord injury

2-         Nerve root injury

3-         Vagus nerve injury

4-         Recurrent laryngeal nerve injury

5-         Horner’s syndrome

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The recurrent laryngeal nerve provides innervation to the vocal cords and was the most common neurologic injury reported in a series of 36,000 patients.  The nerve is felt to be more vulnerable during a right-sided approach because of its anatomic course.  A recent study has also suggested a role for increased endotracheal cuff pressures in this nerve injury.

 

REFERENCES: Flynn TB: Neurologic complications of anterior cervical interbody fusion.  Spine 1982;7:536-539.

Apfelbaum RI, Kriskovich MD, Haller JR: On the incidence, cause, and prevention of recurrent laryngeal nerve palsies during anterior cervical spine surgery.  Spine 2000;25:2906-2912.

 

 

 

 

53.       An otherwise healthy 45-year-old woman reports the onset of severe right leg pain.  Figure 20a shows an axial MRI scan of the L4-5 level, and Figure 20b shows a sagittal view with the arrow at the L4-5 level.  What nerve root is the most likely source of her pain?

 

1-         L3

2-         L4

3-         L5

4-         S1

5-         S2

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The scans show a disk herniation in the far lateral region of the disk.  In particular, the sagittal view shows the herniation adjacent to the exiting L4 nerve root.  Disk herniations in this area that cause symptoms are more likely to compress the nerve exiting at the same level rather than the next most caudal level.

 

REFERENCES: McCulloch JA: Microdiscectomy, in Frymoyer JW (ed): The Adult Spine: Principles and Practice.  New York, NY, Raven Press, 1991, vol 2, pp 1765-1783. 

Hodges SD, Humphreys SC, Eck JC, Covington LA: The surgical treatment of far lateral L3-L4 and L4-L5 disc herniations: A modified technique and outcomes analysis of 25 patients.  Spine 1999;24:1243-1246.

 

 

54.       Which of the following forms of nonsurgical management is considered best for acute low back pain without radiculopathy?

 

1-         Acupuncture

2-         Epidural steroid injections

3-         Facet joint injections

4-         Sclerosant injections

5-         Bed rest

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Temporary bed rest (less than 4 days) with gradual resumption of activities can be efficacious.  Epidural steroid injections may be indicated for acute low back pain with radiculopathy.  Acupuncture, facet joint injections, or ligamentous (sclerosant) injections are not indicated.

 

REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, Appendix A15.

Helfgott SM: Sensible approach to low back pain.  Bull Rheum Dis 2001;3:50.

 

 

 

 

55.       A type 2A hangman’s fracture, which has the potential to overdistract with traction, has which of the following hallmark findings?

 

1-         Anterior translation of greater than 3 mm

2-         Severe angulation with minimal translation

3-         Extension at the fracture site

4-         Associated C1 ring fracture

5-         Associated C2-3 facet dislocation

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Type 2A hangman’s fractures are thought to have a flexion mechanism rather than extension and axial loading.  This allows them to rotate around the anterior longitudinal ligament into flexion.  Anterior translation of greater than 3 mm and angulation distinguish type 2 fractures from type 1 fractures.  Although there is an association between C1 ring fractures and C2 fractures, this does not factor into the classification.  If a C2-3 facet dislocation exists in combination with a C2 pars fracture, it is considered a type 3 fracture.

 

REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine. Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 197-217.

Levine AM, Edwards CC: The management of traumatic spondylolisthesis of the axis.  J Bone Joint Surg Am 1985;67:217-226.

 

 

 

 

56.       Figures 21a and 21b show the radiographs of a 22-year-old man who was shot through the abdomen the previous evening.  An exploratory laparotomy performed at the time of admission revealed a colon injury.  Current examination reveals no neurologic deficits.  Management for the spinal injury should include

 

1-         oral antibiotics for staphylococcus for 48 hours.

2-         oral broad-spectrum antibiotics for 7 days.

3-         IV antibiotics for staphylococcus for 48 hours.

4-         IV broad-spectrum antibiotics for 48 hours.

5-         IV broad-spectrum antibiotics for 7 days.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: IV broad-spectrum antibiotics should be administered for 7 days.  This regimen, when compared to fragment removal or other antibiotic regimens, has been shown to reduce the incidence of spinal infections and reduce the need for metallic fragment removal with perforation of a viscus.

 

REFERENCES: Roffi RP, Waters RL, Adkins RH: Gunshot wounds to the spine associated with a perforated viscus.  Spine 1989;14:808-811. 

Velmahoos GC, Demetriades D: Gunshot wounds of the spine: Should retained bullets be removed to prevent infection?  Ann R Coll Surg Engl 1976;94:85-87.

 

 

 

 

57.       Stability at the atlanto-occipital joint is provided mainly by

 

1-         inherent stability secondary to the shape of the bones.

2-         the apical ligament and the anterior atlanto-occipital ligament.

3-         the transverse ligament.

4-         the tectorial membrane and the alar ligaments.

5-         the accessory ligaments.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The atlanto-occipital joint is inherently unstable and would easily dislocate without the supporting ligaments.  The apical ligament attaches to the basion and tip of the dens but does not provide adequate stability to the joint.  Werne demonstrated that dividing the tectorial membrane and the alar ligaments resulted in gross joint instability.  The anterior longitudinal ligament turns into the anterior atlanto-occipital membrane.  This is called a membrane rather than a ligament because it is not strong enough to support these two structures.

 

REFERENCES: Werne S: Studies in spontaneous atlas dislocation.  Acta Orthopaedica Scandinavica 1977;23(supplement).

Jarrett PJ, Whitesides TE Jr: Injuries of the cervicocranium, in Browner BD, Jupiter JB, Levine AM, Trafton PG (eds): Skeletal Trauma.  Philadelphia, PA, WB Saunders, 1992, pp 665-697.

 

 

58.       Which of the following are considered characteristic features of degeneration of a disk?

 

1-         Reduced water and glycosaminoglycan content and increased noncollagen glycoprotein

2-         Reduced water and glycosaminoglycan content and reduced noncollagen glycoprotein

3-         Reduced water content, increased glycosaminoglycan content, and increased noncollagen glycoprotein

4-         Increased water and glycosaminoglycan content and increased noncollagen glycoprotein

5-         Increased water and glycosaminoglycan content and reduced noncollagen glycoprotein

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Gradual dessication of the disk begins in the third decade as glycosaminoglycan levels within the nucleus begin to decline.  The original water content of 88% decreases to 70% in the sixth decade and beyond.  As glycosaminoglycan content decreases, there is a corresponding increase in noncollagen glycoprotein.

 

REFERENCES: Happey F, Weissman A, Naylor A: Polysaccharide content of the prolapsed nucleus pulposus of the human intervertebral disc.  Nature 1961;192:868.

Naylor A, Shentall R: Biomechanical aspects of intervertebral discs in aging and disease, in Jayson M (ed): The Lumbar Spine and Back Pain.  New York, NY, Grune and Stratton Inc, 1976, pp 317-326.

Watkins RG, Collis JS: Lumbar Discectomy and Laminectomy.  Rockville, MD, Aspen, 1987, pp 2-3.

 

 

 

 

59.       What spinal nerves in the cauda equina are primarily responsible for innervation of the bladder?

 

1-         L1, L2, and L3

2-         L4 and L5

3-         L5 and S1

4-         S2, S3, and S4

5-         Filum terminale

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The spinal nerves primarily responsible for bladder function are the S2, S3, and S4 nerve roots.  With significant compression of the cauda equina by either disk herniation, tumor, or degenerative stenosis, bladder dysfunction may result.

 

REFERENCES: Hoppenfeld S: Physical Examination of the Spine and Extremities.  Norwalk, CT, Appleton-Century-Crofts, 1976, p 254.

Pick TP, Howden R (edS): Gray’s Anatomy.  New York, NY, Bounty Books, 1977, p 1004.

 

60.       Figures 22a and 22b show the radiograph and sagittal MRI scan of the upper cervical spine of a 62-year-old woman who has had a long history of rheumatoid arthritis.  Following hospitalization and skeletal traction, her symptoms improve significantly, her neurologic examination returns to normal, and repeat radiographs show a normal occiput and C1-C2 relationship.  Treatment should now include

 

1-         C1 laminectomy.

2-         transoral removal of the odontoid.

3-         occipitocervical stabilization.

4-         cervical laminoplasty.

5-         foramen magnum decompression.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Although opinions differ on whether a decompression is indicated in a patient with symptomatic basilar invagination, it is generally agreed that occipitocervical stabilization is indicated.  This has been done with and without concomitant arthrodesis.

 

REFERENCES: Crockard HA, Grob D: Rheumatoid arthritis upper cervical involvement, in Clark CR (ed): The Cervical Spine, ed 3.  Philadelphia, PA, Lippincott Raven, 1998, p 701.

Crockard HA, Calder I, Ransford AO: One-stage transoral decompression and posterior fixation in rheumatoid atlanto-axial subluxation.  J Bone Joint Surg Br 1990;72:682-685.

 

 

 

 

61.       What is the prognosis for ambulation, from best to worst, for patients with an incomplete spinal cord injury?

 

1-         Central cord syndrome, anterior cord syndrome, Brown-Sequard syndrome

2-         Central cord syndrome, Brown-Sequard syndrome, anterior cord syndrome

3-         Brown-Sequard syndrome, anterior cord syndrome, central cord syndrome

4-         Brown-Sequard syndrome, central cord syndrome, anterior cord syndrome

5-         Anterior cord syndrome, central cord syndrome, Brown-Sequard syndrome

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Of the incomplete spinal cord injuries, Brown-Sequard syndrome has the best prognosis for ambulation.  Central cord syndrome has a variable recovery.  Anterior cord syndrome has the worst prognosis, with motor recovery rare below the level of the injury.

 

REFERENCES: Apple DF: Spinal cord injury rehabilitation, in Herkowitz HN, Garfin SR, Balderston RA, Eismont FJ, Bell GR, Wiesel SW (eds): Rothman-Simeone The Spine, ed 4.  Philadelphia, PA, WB Saunders, 1999, pp 1130-1131.

Northrup BE: Evaluation and early treatment of acute injuries to the spine and spinal cord, in Clark CR (ed): The Cervical Spine, ed 3.  Philadelphia, PA, Lippincott Raven, 1998, pp 544-545.

 

 

 

62.       A skeletally mature 15-year-old girl who was thrown from the car in a rollover accident sustained the injuries shown in Figures 23a through 23d.  Examination reveals no neurologic deficit, but the patient has moderate posterior spinal tenderness at the level of the injury.  What is the most appropriate treatment?

 

1-         Chairback brace

2-         Thoracolumbosacral orthosis (TLSO) molded in extension

3-         Posterior stabilization of the fracture with segmental fixation and iliac crest bone grafting

4-         Anterior corpectomy, strut grafting, and plating

5-         Combined anterior corpectomy, structural grafting and plating, and posterior stabilization and fusion

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The majority of patients with thoracolumbar burst fractures without neurologic deficit can be effectively treated with a TLSO or a hyperextension body cast.  Indications for surgery are neurologic deficit and/or significant deformity (greater than 50% loss of anterior vertebral body height or marked kyphosis).

 

REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 197-217.

Chow GH, Nelson BJ, Gebhard JS, Brugman JL, Brown CW, Donaldson DH: Functional outcome of thoracolumbar burst fractures managed with hyperextension casting or bracing and early mobilization.  Spine 1996;21:2170-2175.

 

 

 

 

63.       The MRI scan shown in Figure 24 reveals a right-sided herniated nucleus pulposus at L4-5 in a patient with pain in the right leg.  Administration of a caudal epidural steroid injection provides immediate relief.  Over the next week he notes generalized weakness of the lower extremities and has one episode of urinary incontinence.  What is the next most appropriate step in management?

 

1-         Nonsteroidal anti-inflammatory drugs and reassurance that this is a steroid flare reaction that should subside within 2 to 3 days

2-         Emergent L4-5 diskectomy

3-         Repeat epidural steroid injection at L4-5 under fluoroscopy

4-         MRI of the lumbar spine

5-         Myelography and CT

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Whenever a patient’s condition changes following a test or a procedure, the physician must determine the cause.  A steroid flare reaction will not cause incontinence or weakness of the lower extremities.  An L4-5 diskectomy may alleviate the problem if the right-sided L4-5 disk herniation is the etiology of the symptoms.  However, it is unlikely that a right-sided disk herniation alone will cause a cauda equina syndrome.  Possible etiologies include a further extrusion of a disk fragment at L4-5 that now obliterates the spinal canal, a disk herniation at another level, or an epidural abscess following injection of corticosteroids through a caudal approach.  In the presence of a possible infection, myelography should not be performed from a lumbar puncture.  The fastest and least invasive way to make an appropriate diagnosis is to obtain an MRI of the lumbar spine.  In this patient, the MRI revealed an epidural abscess that was compressing the cauda equina.  Because of the large dose of steroids that were injected, the patient did not manifest symptoms such as fevers and chills until late in the course.

 

REFERENCES: Knight JW, Cordingley JJ, Palazzo MG: Epidural abscess following epidural steroid and local anaesthetic injection.  Anaesthesia 1997;52:576-578.

Abram SE, O’Connor TC: Complications associated with epidural steroid injections.  Reg Anesth 1996;21:149-162.

 

 

 

 

64.       At the L4-5 level, what is the location of the S2-5 nerve roots in relationship to the L5 and S1 nerve roots?

 

1-         They are lateral and dorsal to L5 and S1.

2-         They are lateral and ventral to L5 and S1.

3-         They are in the midline and dorsal to L5 and S1.

4-         They are in the midline and ventral to L5 and S1.

5-         There is no clear anatomic arrangement.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The nerve roots of S2-5 are positioned dorsally and in the midline relative to the L5 and S1 nerve roots.  The L5 nerve root is located lateral to S1 as it prepares to exit under the L5 pedicle.  The S1 nerve root is located lateral and ventral to the S2-5 nerve roots.

 

REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 3-17.

Cohen MS, Wall EJ, Olmarker K, Rydevik BL, Garfin SR: Anatomy of the spinal nerve roots in the lumbar and lower thoracic spine, in Herkowitz HN, Garfin SR, Balderston RA, Eismont FJ, Bell GR, Wiesel SW (eds): Rothman and Simeone The Spine, ed 4.  Philadelphia, PA, WB Saunders, 1999, vol 1, pp 84-86.

 

 

 

 

65.       A comparison of dural tears repaired with suture alone and those treated by suture with fibrin glue supplementation will reveal which of the following findings?

 

1-         Delayed arachnoid interposition with fibrin glue supplementation

2-         Delayed primary dural healing with fibrin glue supplementation

3-         A more marked inflammatory response with fibrin glue supplementation

4-         Higher infection rates with fibrin glue supplementation

5-         No significant differences

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Animal studies assessing the influence of fibrin glue supplementation have detected a markedly greater inflammatory response at the site of application.  An increased incidence of infection and delays in healing were not noted.

 

REFERENCES: Cain JE Jr, Rosenthal HG, Broom MJ, Jauch EC, Borek DA, Jacobs RR: Quantification of leakage pressures after durotomy repairs in the canine.  Spine 1990;15:969-970.

Cain JE Jr, Dryer RF, Barton BR: Evaluation of dural closure techniques: Suture methods, fibrin adhesive sealant, and cyanoacrylate polymer.  Spine 1988;13:720-725.

 

 

 

 

66.       A 19-year-old woman reports lower back pain following a motor vehicle accident.  Radiographs obtained immediately after the accident and a bone scan obtained 4 weeks later are shown in Figures 25a through 25c.  The patient asks questions regarding the cause, genetics, and natural history of her condition.  She should be informed that the condition was

 

1-         caused by the accident, exists in 5% of the population, has no familial predisposition, and is unlikely to progress.

2-         caused by the accident, exists in 12% of the population, has no familial predisposition, and is unlikely to progress.

3-         preexisting to her accident, exists in 3% of the population, has no familial predisposition, and should be monitored for progression yearly until age 25 years.

4-         preexisting to her accident, exists in 5% of the population, has a familial predisposition, and is unlikely to progress.

5-         preexisting to her accident, exists in 12% of the population, has a familial predisposition, and is likely to progress throughout adulthood.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The radiographs show L5 spondylolysis without spondylolisthesis (slip).  The bone scan is normal, indicating that the pars interarticularis fractures are not acute.  The incidence of spondylolysis is approximately 5% in the general population.  The lesion generally develops in children age 5 to 6 years, and there is a second peak in the adolescent population.  There is a familial predisposition, with reported rates of 27% to 69% in close relatives.  A recent long-term follow-up study found that 90% of the spondylolisthesis had occurred before the patient’s first visit to the physician.  Spondylolisthesis tends to progress during the initial growth spurt and is similar in some respects to idiopathic scoliosis.  Progression of a lytic spondylolysis to spondylolisthesis in adulthood has been reported; however, this is exceedingly rare.

 

REFERENCES: Lauerman WC, Cain JE: Isthmic spondylolisthesis in the adult.  J Am Acad Orthop Surg 1996;4:201-208.

Hensinger RN: Spondylolysis and spondylolisthesis in children and adolescents.  J Bone Joint Surg Am 1989;71:1098-1107.

Seitsalo S, Osterman K, Hyvarinen H, Tallroth K, Schlenzka D, Poussa M: Progression of spondylolisthesis in children and adolescents: A long-term follow-up of 272 patients.  Spine 1991;16:417-421.

Fredrickson BE, Baker D, McHolik WJ, Yuan HA, Lubicky JP: The natural history of spondylolysis and spondylolisthesis.  J Bone Joint Surg Am 1984;66:699-707.

 

 

 

 

67.       A patient underwent an anterior cervical diskectomy and interbody fusion for a C5-6 herniated nucleus pulposus and left C6 radiculopathy 8 months ago. He now reports new onset of severe neck pain and left C6 radicular pain, with wrist extension weakness.  The radiograph and CT scan shown in Figures 26a and 26b reveal pseudarthrosis at C5-6.  The next step in management should consist of

 

1-         application of a neck brace for 6 to 12 weeks.

2-         revision anterior diskectomy and interbody fusion with autograft at C5-6.

3-         revision anterior diskectomy with interbody autograft and anterior plate fixation at C5-6.

4-         posterior fusion at C5-6.

5-         posterior foraminotomy at left C6 and posterior fusion at C5-6 with stabilization and autograft.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Brodsky and associates reviewed 34 cases of cervical pseudarthrosis after anterior fusion.  Seventeen were treated with revision anterior fusion and 17 with posterior foraminotomy and fusion.  Good results were seen in 75% of patients who underwent revision anterior surgery, but better results (94%) were seen with posterior surgery, including foraminotomy and stabilization.  Tribus and associates reported treatment of 16 patients with pseudarthrosis using revision anterior debridement of the fibrous tissue and fusion with autograft and plates.  There was improvement of the neck in 75% of the patients, nonunion in 19%, continued weakness in 28%, and dysphagia in 5%.  Farey and associates reported on 19 patients treated with posterior foraminotomy, stabilization, and fusion with a fusion rate of 100%, resolution of arm pain in 94%, resolution of weakness in 100%, and resolution of neck pain in 75%.  It would appear that posterior foraminotomy is more effective for relieving arm pain and neurologic deficits associated with pseudarthrosis.  Posterior fusion has the most reliable rate of arthrodesis in this setting.  Dysphagia is reported in some patients undergoing more extensive anterior dissections required for applying plates.  A neck brace is unlikely to aid in healing of pseudarthrosis in a patient who underwent surgery 8 months ago.  A neck brace would be most effective within the first 3 months if a delayed union is identified.

 

REFERENCES: Brodsky AE, Khalil MA, Sassard WR, Neuman BP:  Repair of symptomatic pseudarthrosis of anterior cervical fusion: Posterior versus anterior repair.  Spine
1992;17:1137-1143.

Tribus CB, Corteen DP, Zdeblick TA: The efficacy of anterior cervical plating in the management of symptomatic pseudarthrosis of the cervical spine. Spine 1999;24:860-864.

Farey ID, McAfee PC, Davis RF, Long DM: Pseudarthrosis of the cervical spine after anterior arthrodesis: Treatment by posterior nerve root decompression, stabilization, and arthrodesis. 
J Bone Joint Surgery Am 1990;72:1171-1177.

 

 

 

 

68.       A 44-year-old farmer involved in a rollover accident on his tractor sustained an L1 burst fracture with a 20% loss of anterior vertebral body height, 30% canal compromise, and 15 degrees of kyphosis.  He remains neurologically intact.  The preferred initial course of action should consist of

 

1-         posterior spinal fusion with instrumentation.

2-         a thoracolumbosacral orthosis (TLSO) extension brace and early mobilization.

3-         bed rest for 6 weeks followed by mobilization in a cast.

4-         anterior L1 corpectomy and fusion with instrumentation.

5-         anterior corpectomy followed by posterior fusion with instrumentation.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Surgical decompression is unnecessary in a patient with no neurologic deficit and canal compromise of less than 50%.  A compression deformity of less than 50% and kyphosis of less than 30 degrees may be successfully treated with a TLSO extension brace. Deformity in this range will reliably heal with minimal risk for late deformity or residual pain. Although some studies suggest 6 weeks of bed rest as treatment, early mobilization and bracing is preferred.

 

REFERENCES: Hartman MB, Chrin AM, Rechtine GR: Nonoperative treatment of thoracolumbar fractures.  Paraplegia 1995;33:73-76.

Chow GH, Nelson BJ, Gebhard JS, Brugman JL, Brown CW, Donaldson DH: Functional outcome of thoracolumbar burst fractures managed with hyperextension casting or bracing and early mobilization.  Spine 1996;21:2170-2175.

Kraemer WJ, Schemitsch EH, Lever J, McBroom RJ, McKee MD, Waddel JP: Functional outcome of thoracolumbar burst fractures without neurological deficit.  J Orthop Trauma 1996;10:541-544.

 

 

 

 

69.       A 40-year-old carpenter has a 3-month history of right arm pain and neck pain that now leaves him unable to work.  Examination reveals a positive Spurling test, weakness of the biceps, and a mildly positive Hoffman’s sign on the right side.  Electromyography and nerve conduction velocity studies show a right C6 deficit.  Figures 27a through 27c show MRI scans that reveal two-level spondylotic disease at C5-6 and C6-7, a large herniated nucleus pulposus at C5-6, and a prominent ridge and hard disk at C6-7.  Nonsurgical management fails to provide relief, so the patient elects surgical intervention.  Which of the following surgical options would give the best long-term results?

 

1-         Posterior keyhole foraminotomy, diskectomy, and decompression on the right side at C5-6

2-         Anterior cervical diskectomy with no fusion

3-         Anterior cervical diskectomy with interbody fusion (Smith-Robinson) at C5-6

4-         Anterior cervical diskectomy with interbody fusion (Smith-Robinson) at C6-7

5-         Two-level diskectomy at C5-6 and C6-7, with fusion at C5-7

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The patient has a single-level deficit by clinical examination but an adjacent level that may be pathologic. Hilibrand and associates, in a review of 374 patients with myeloradiculopathy treated with single-level or multilevel anterior cervical diskectomy and fusion, showed that 25% of patients had an occurrence of new radiculopathy or myelopathy at an adjacent level within 10 years after surgery.  Reoperation rates were highest in those patients where the adjacent nonfused segment was C5-6 or C6-7.  Those patients who had multilevel fusions had a lower incidence of adjacent segment disease.  The authors recommended incorporating an adjacent level in the initial procedure in patients with myelopathy or radiculopathy when significant disease was noted.  Posterior keyhole foraminotomy is an excellent procedure for single-level radiculopathy but is not effective in relieving myelopathy.  Anterior cervical diskectomy without fusion has an increased incidence of hypermobility and neck pain on long-term follow-up.  In a later review, these authors reported improved fusion rates and better clinical outcomes with the use of strut fusions instead of multilevel interbody grafts.

 

REFERENCES: Hilibrand AS, Carlson GD, Palumbo MA, Jones PK, Bohlman HH: Radiculopathy and myelopathy at segments adjacent to the site of a previous anterior cervical arthrodesis.  J Bone Joint Surg Am 1999;81:519-528.

Henderson CM, Hennessy RG, Shuey HM Jr, Shackelford EG: Posterior-lateral foraminotomy as an exclusive operative technique for cervical radiculopathy: A review of 846 consecutively operated cases.  Neurosurgery 1983;13:504-512.

Hilibrand AS, Fye MA, Emery SE, Palumbo MA, Bohlman HH: Impact of smoking on the outcome of anterior cervical arthrodesis with interbody or strut grafting.  J Bone Joint Surg Am 2001;83:668-673.

 

 

 

 

70.       A patient with rheumatoid arthritis has an unstable pseudarthrosis after undergoing C1-2 posterior fusion.  No neurologic deficits are noted, and repair with posterior transarticular fixation screws and a posterior wiring technique at C1-2 is planned.  Which of the following preoperative studies offers the best visualization?

 

1-         Lateral flexion-extension radiographs centered over C1-2

2-         Cervical MRI

3-         Thin-cut CT through the C1-2 and C2-3 segments

4-         Vertebral artery angiography

5-         Electromyography of the cervical roots and spinal cord

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Dickman and associates reported a greater than 10% incidence of vertebral artery anomalies at the C1-2 junction that would preclude the use of either unilateral or bilateral transarticular screw placement.  They noted that 13 of 105 patients had a high-riding transverse foramen that precluded bilateral screw placement.  In another series, 17 of 94 patients had unilateral high-riding transverse foramina and three had bilateral anomalies.  Thin-cut CT with sagittal reconstructions offers the best visualization of the anomalous position of the vertebral artery.  They noted that single screw placement in combination with posterior C1-2 fusion was an effective means to secure C1-2 stability.  MRI gives excellent visualization of soft tissues and spinal cord compression but is not as clear as thin-cut CT for visualization of the vertebral artery foramina.  Vertebral artery angiography is an invasive study with an inherent potential for complications.  Electromyography does not correlate with vertebral artery anatomy.

 

REFERENCES: Paramore CG, Dickman CA, Sonntag VK: The anatomic suitability of the C1-2 complex for transarticular screw fixation.  J Neurosurg 1996;85:221-224.

Dickman CA, Sonntag VK: Posterior C1-C2 transarticular screw fixation for atlantoaxial arthrodesis.  Neurosurgery 1998;43:275-280.

Song GS, Theodore N, Dickman CA, Sonntag VK: Unilateral posterior atlantoaxial transarticular Screw fixation.  J Neurosurg 1997;87:851-855.

 

 

 

 

71.       An elderly patient falls and sustains an extension injury to the neck that results in upper extremity weakness, spared perianal sensation, and lower extremity spasticity.  These findings best describe what syndrome?

 

1-         Brown-Sequard 

2-         Cauda equina  

3-         Anterior cord 

4-         Posterior cord 

5-         Central cord 

 

PREFERRED RESPONSE: 5

 

DISCUSSION: These finding indicate central cord syndrome, and injury that is more common in the older population who have some degree of spondylosis.  The physiologic insult can be a central spinal hematoma with resultant hematomyelia.  Bowel and bladder functional return has a good prognosis, unlike the upper extremity motor loss.  Cauda equina syndrome generally involves injury at the lumbar levels, with some degree of lower extremity motor loss.  Posterior cord syndrome is characterized by preservation of motor function below the level of injury and position/vibratory sensory loss.  Brown-Sequard syndrome, which is often produced by a penetrating injury, results in contralateral hypalgesia and ipsilateral weakness.  Anterior cord syndrome has a poor prognosis for functional return; lower extremity findings include loss of light touch, sharp/dull, and temperature sensations below the level of injury, as well as
motor function.

 

REFERENCES: Apple DF Jr: Spinal cord injury rehabilitation, in Rothman RH, Simeone FA (eds): The Spine, ed 3. Philadelphia, PA, WB Saunders, 1992, Chapter 31.

Leventhal MR: Fractures, dislocations and fracture-dislocations of spine, in Crenshaw AH (ed): Campbell’s Operative Orthopaedics, ed 8.  St. Louis, MO, Mosby, 1992.

 

 

 

 

72.       In the treatment of thoracic disk herniations, what approach is associated with the highest risk of iatrogenic paraplegia?

 

1-         Laminectomy

2-         Costotransversectomy

3-         Transpedicular

4-         Transthoracic

5-         Thoracoscopic

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Laminectomy is associated with the highest risk of iatrogenic paraplegia because retraction on the cord is necessary for visualization, but retraction is difficult because of tethering of the intradural dentate ligaments.  All of the other approaches allow for access to the disk herniation through an angle that avoids the cord itself, although other limitations may exist.

 

REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 87-96.

Stillerman CB, Chen TC, Couldwell WT, Zhang W, Weiss MH: Experience in the surgical mangement of 82 symptomatic herniated thoracic discs and review of the literature.  J Neurosurg 1998;88:623-633.

 

 

 

 

73.       Which of the following factors is the strongest predictor of vertebral fracture in postmenopausal women?

 

1-         Positive family history of vertebral fracture

2-         Menopause before age 40 years

3-         History of two vertebral fractures without significant trauma

4-         Bone mineral density two standard deviations below normal

5-         Positive history for smoking

 

PREFERRED RESPONSE: 3

 

DISCUSSION: If a woman has two or more osteoporotic compression fractures, her risk of another is increased 12 fold.  A decrease of two standard deviations in bone mineral density increases the risk four to six fold, a positive family history 2.7 fold, premature menopause 1.6 fold, and smoking 1.2 fold.  It should be noted that these studies were carried out in Caucasian and Asian women.

 

REFERENCES: Melton LJ III: Epidemiology of spinal osteoporosis.  Spine 1997;22:2S-11S.

Ross PD, Davis JW, Epstein RS, Wasnich RD: Pre-existing fractures and bone mass predict vertebral fracture incidence in women.  Ann Intern Med 1991;114:919-923.

 

 

 

 

74.       A 23-year-old man sustains a unilateral jumped facet with an isolated cervical root injury in a motor vehicle accident.  Acute reduction results in some initial improvement of his motor weakness.  Over the next 48 hours, examination reveals ipsilateral loss of pain and temperature sensation in his face, limbs, and trunk, as well as nystagmus, tinnitus, and diplopia.  What is the most likely etiology for these changes?

 

1-         Intracranial hemorrhage

2-         Epidural hematoma

3-         Unrecognized disk extrusion

4-         Delayed spinal cord hemorrhage

5-         Vertebral artery injury

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The patient is showing signs of vertebral artery stroke.  The signs of Wallenberg syndrome include those listed above, as well as contralateral loss of pain and temperature sensation throughout the body, an ipsilateral Horner’s syndrome, dysphagia, and ataxia.  Vertebral artery injuries are not unusual in significant cervical facet injuries.  A lesion in the cervical spinal cord is not associated with these symptoms, and an intracranial hemorrhage from trauma is unlikely to present in this manner.

 

REFERENCES: Young PA, Young PH: Basic Clinical Neuroanatomy.  Baltimore, MD, Williams and Wilkins, 1997, pp 242-243.

Hauop JS, et al: The cause of neurologic deterioration after acute cervical spinal cord injury.  Spine 2001;26:340-346.

Veras LM, Pedraza-Gutierrez S, Castellanos J, Capellades J, Casamitjana J, Rovira-Canellas A: Vertebral artery occlusion after acute cervical spine trauma.  Spine 2000;25:1171-1177.

 

 

75.       A 60-year-old woman with a history of breast cancer has progressive paraparesis.  The MRI scan is shown in Figure 28.  What form of management is most likely to restore or maintain ambulation?

 

1-         Radiation therapy and a thoracolumbosacral orthosis

2-         Laminectomy alone

3-         Laminectomy and radiation therapy

4-         Laminectomy and posterior fusion

5-         Anterior decompression and stabilization

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Surgical decompression and stabilization have been shown to be the most effective means of improving neurologic function.  Decompression is most reliably done from the side of the compression, which is anterior in this patient.

 

REFERENCES: Harrington KD: Metastatic tumors of the spine: Diagnosis and treatment.  J Am Acad Orthop Surg 1993;1:76-86.

Siegal T, Siegal T: Current considerations in the management of neoplastic spinal cord compression.  Spine 1989;14:223-228.

 

 

 

 

76.       Figures 29a and 29b show the AP and lateral radiographs of a 30-year-old man who has increasingly worse back pain and stiffness.  Examination shows painful, limited spinal range of motion.  There is no neurologic deficit.  What laboratory study would be most helpful in confirming the diagnosis?

 

1-         HLA-B27

2-         Prostate-specific antigen

3-         Rheumatoid factor

4-         Antinuclear antibody

5-         Serum protein electrophoresis

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The radiographs show ankylosing spondylitis with sclerosis of the sacroiliac joints and a “bamboo spine” in the lumbar region.  HLA-B27 is positive in 80% to 90% of patients with ankylosing spondylitis and in about 8% of the general population.  The findings do not represent diffuse idiopathic skeletal hyperostosis (DISH), which is a radiographic diagnosis in which there are three consecutive levels of nonmarginated osteophytes without disk degeneration.

 

REFERENCES: Calin A: Ankylosing spondylitis.  Clin Rheum Dis 1985;11:41-60.

Booth R, Simpson J, Herkowitz H: Arthritis of the spine, in Herkowitz HH (ed): The Spine, ed 4.  Philadelphia, PA, WB Saunders, 1992, p 431.

van der Linden S, Valkenburg H, Cats A: The risk of developing ankylosing spondylitis in HLA-B27 positive individuals: A family and population study.  Br J Rheumatol 1983;22:18-19.

 

 

 

 

77.       A 29-year-old man undergoes surgery for a grade I isthmic spondylolisthesis at L5.  Following surgery, what type of brace will best immobilize the L5-S1 motion segment?

 

1-         Lumbosacral canvas corset

2-         Chairback brace

3-         Thoracolumbosacral orthosis

4-         Thoracolumbosacral orthosis with thigh extension

5-         Sacral extension belt

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The thoracolumbosacral orthosis with thigh extension best immobilizes the lumbosacral junction.  Fidler and Plasmans have demonstrated increased motion at the lumbosacral junction with the standard chairback-type brace.

 

REFERENCES: Connolly PJ, Grob D: Bracing of patients after fusion for degenerative problems of the lumbar spine: Yes or no?  Spine 1998;23:1426-1428.

Fidler MW, Plasmans CM: The effect of four types of support on the segmental mobility of the lumbosacral spine.  J Bone Joint Surg Am 1983;65:943-947.

 

 

78.       When examining a patient with marked hyperreflexia, which of the following findings best suggests that the condition is not caused by a cerivcal spine pathology?

 

1-         Positive finger adduction test and finger escape sign

2-         Positive grip and release test and rapid opening and closing of the hand

3-         Positive jaw jerk reflex

4-         Extensor Babinski response

5-         Loss of proprioception in the great toes

 

PREFERRED RESPONSE: 3

 

DISCUSSION: A positive jaw jerk reflex suggests that the problem is above the level of the pons.  All of the other physical signs are exhibited in patients with cervical myelopathy.  Although these signs also may be present in conditions affecting the brain, they do not help differentiate between a brain etiology and a cervical spine etiology.  A jaw jerk reflex, however, is not present in patients with cervical myelopathy alone.

 

REFERENCES: Montgomery DM, Brower RS: Cervical spondylotic myelopathy: Clinical syndrome and natural history.  Orthop Clin North Am 1992;23:487-493.

Ono K, Ebara S, Fuji T, Yonenobu K, Fujiwara K, Yamashita K: Myelopathy hand: New clinical signs of cervical cord damage.  J Bone Joint Surg Br 1987;69:215-219.

An HS, Simpson JM: Surgery of the Cervical Spine.  Baltimore, MD, Williams and
Wilkins, 1994.

 

 

 

 

79.       The artery of Adamkiewicz (arteria radicularis, arteria magna) is most commonly found on the

 

1-         right side between T5 and T7.

2-         right side between T9 and T11.

3-         left side between T5 and T7.

4-         left side between T9 and T11.

5-         left side between L1 and L3.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Approximately 75% of people have the artery on the left side between T9 and T11.  Its relevance to iatrogenic spinal cord problems is still uncertain.

 

REFERENCES: Stambaugh J, Simeone F: Vascular complication in spine surgery, in Herkowitz HH (ed): The Spine, ed 4.  Philadelphia, PA, WB Saunders, 1992, p 1715.

Lazorthes G: Arterial vascularization of the spinal cord.  J Neurosurg 1971;35:253-262.

 

 

80.       A 62-year-old man with a long history of ankylosing spondylitis has neck pain after lightly bumping his head on the wall.  Examination reveals neck pain with any attempted motion; the neurologic examination is normal.  Plain radiographs show extensive ankylosis of the cervical spine and kyphosis but no fracture.  What is the next most appropriate step in management?

 

1-         Application of a rigid collar and follow-up radiographs in 1 week

2-         Gardner-Wells tongs and in-line traction

3-         Hospital admission and frequent neurologic checks

4-         Immobilization of the neck, followed by CT with reconstruction

5-         Flexion-extension radiographs to evaluate for any occult instability

 

PREFERRED RESPONSE: 4

 

DISCUSSION: A high level of suspicion must be given for a fracture in any patient with ankylosing spondylitis who reports neck pain, even with minimal or no trauma.  The neck should be immobilized in its normal position, which is often kyphotic, and plain radiographs should be obtained.  If no obvious fracture is seen, CT with reconstruction should be obtained.  The placement of in-line traction can have catastrophic effects because it may malalign the spine.

 

REFERENCES: Brigham CD: Ankylosing spondylitis and seronegative spondyloarthropathies, in Clark CR (ed): The Cervical Spine, ed 3.  Philadelphia, PA, Lippincott Raven, 1998,
pp 724-727.

McDowell GS, Cammisa FP, Eismont FJ: Hyperextension injuries of the cervical spine, in Levine AM, Eismont FJ, Garfin SR, Zigler JE (eds): Spine Trauma.  Philadelphia, PA,
WB Saunders, 1998, pp 372-374.

 

 

 

 

81.       A young man sustains a lumbar strain in an on-the-job motor vehicle accident.  Both he and his treating physician feel that he is capable of limited duty with appropriate restrictions shortly after the injury.  What term best describes his work status?

 

1-         Temporary total disability

2-         Temporary partial disability

3-         Temporary partial illness

4-         Permanent total disability

5-         Permanent partial disability

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Because the man is only recently removed from his injury and is judged capable of returning to work with some restrictions, the term that best describes his work status is temporary partial disability.

 

REFERENCE: Beaty JH (ed):  Orthopaedic Knowledge Update 6.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 131-137.

 

82.       Based on the findings seen at C5-6 in Figure 30, the most likely deficit for this patient will be weakness of the

 

1-         deltoid.

2-         wrist flexor.

3-         wrist extensor.

4-         triceps.

5-         grip.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: A herniated cervical disk at C5-6 causes a C6 radiculopathy.  There are eight cervical nerve roots and seven cervical vertebrae, and C8 exits between the C7 and T1 vertebrae.  The C6 nerve root typically innervates the biceps and wrist extensor.  The deltoid is predominantly innervated by C5.  The wrist flexor and triceps are predominantly innervated by C7.  Grip strength is predominantly a function of C8.

 

REFERENCE: Hoppenfeld S: Evaluation of nerve root lesions involving the upper extremity, in Orthopaedic Neurology.  Philadelphia, PA, JB Lippincott, 1977, pp 7-23.

 

 

 

 

83.       A 40-year-old woman with no history of back problems has a symptomatic L4-5 disk herniation with an L5 radiculopathy that has failed to respond to 12 weeks of nonsurgical management.  In the preoperative discussion, the surgeon advises the patient that the chance of recurrence of the herniation after successful diskectomy is what percent?

 

1-         0%

2-         1%

3-         5% to 10%

4-         30% to 40%

5-         70% to 80%

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The incidence of recurrent disk herniation after a successful diskectomy is approximately 5% to 10%.  Indications for surgical diskectomy for a recurrence are the same as for a primary diskectomy.

 

REFERENCES: Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 685-698.

Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 127-139.

 

 

 

 

84.       In the normal adult, the distance between the basion and the tip of the dens with the head in neutral position is how many millimeters?

 

1-         2 to 3

2-         4 to 5

3-         6 to 7

4-         7 to 8

5-         9 to 10

 

PREFERRED RESPONSE: 2

 

DISCUSSION: In the normal adult, the distance between the basion and the tip of the dens is 4 mm to 5 mm.  Any distance greater than 5 mm is considered abnormal. This is one way to detect occipitocervical dissociation other than using the Power’s ratio, which relies on an anterior dislocation.

 

REFERENCES: Wiesel SW, Rothman RH: Occipitoatlantal hypermobility.  Spine 1979;4:187-191.  

Wholey MH, Browner AJ, Baker HL Jr: The lateral roentgenogram of the neck: With comments on the atlanto odontoid-basion relationship.  Radiol 1958;71:350-356.

 

 

 

 

85.       The postoperative neurologic prognosis of a patient who has a tumor that is compressing the spinal cord and causing a neurologic deficit depends primarily on the

 

1-         pretreatment neurologic status.

2-         extent of spinal cord compression.

3-         extent of bony deformity.

4-         MRI findings.

5-         dimension of the spinal canal.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The tumor biology, location, and pretreatment neurologic status are the best predictors of a patient’s postoperative neurologic prognosis.  Between 60% to 90% of patients who are ambulatory at the time of diagnosis will retain this ability after treatment.  Location is important in that less space is available for the cord in the thoracic spine.  Lesions located in vascular watershed regions may disrupt the vascular supply of the cord.

 

REFERENCES: Weinstein JN: Differential diagnosis and surgical treatment of primary benign and malignant neoplasms, in Frymoyer JW (ed): The Adult Spine: Principles and Practice.  New York, NY, Raven Press, 1991, vol 1, pp 829-860.

Siegal T, Siegal T: Current considerations in the management of neoplastic spinal cord compression.  Spine 1989;14:223-228.

 

 

 

 

86.       An otherwise healthy 32-year-old man who underwent an uneventful L5-S1 lumbar microdiskectomy 6 weeks ago now reports increasing and severe back pain that awakens him from sleep.  Examination reveals a benign-appearing wound, and the neurologic examination is normal.  Laboratory studies show an erythrocyte sedimentation rate (ESR) of 90 mm/h and a WBC of 9,000/mm3.  Plain radiographs are normal.  What is the next most appropriate step in management?

 

1-         Oral antibiotics for staphylococcus

2-         Repeat laboratory studies in 1 week to recheck the ESR

3-         MRI with gadolinium

4-         Biopsy of the surgical disk space

5-         Irrigation and debridement of the surgical wound in the operating room

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The patient’s history and laboratory studies are very suspicious for a postoperative diskitis.  The predominant symptom often is back pain.  An ESR of 90 mm/h is considered significantly elevated and normally would be expected to return to near baseline by 2 weeks postoperatively.  A normal WBC result is not unusual with postoperative diskitis.  Management should consist of an MRI with gadolinium to confirm the diagnosis, followed by a biopsy percutaneously to obtain tissues for pathology and microbiology.  Surgical debridement is reserved for patients whose percutaneous biopsy results are negative and a high index of suspicion for diskitis remains, or when management consisting of IV antibiotics, bed rest, and spinal immobilization fails to provide relief.

 

REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 257-271.

Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 713-721.

 

 

 

 

87.       An 81-year-old man with severe low back pain reports right extensor hallucis longus and anterior tibialis weakness and difficulty urinating over the past 24 hours.  He has a temperature of 101 degrees F (38.3 degrees C).  MRI scans are shown in Figures 31a and 31b.  Management should consist of

 

1-         hospital admission for IV antibiotics and observation.

2-         an epidural steroid.

3-         anterior diskectomy and fusion with autologous bone graft.

4-         laminectomy for decompression and debridement.

5-         laminectomy for decompression with an instrumented posterolateral fusion.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: An epidural abscess with neurologic deficit represents a medical and surgical emergency.  The prognosis is related to the timeliness of diagnosis and treatment.  Once identified, the primary treatment is surgical decompression of the abscess, followed by organism-specific antibiotics.  In the absence of a significant anterior process such as diskitis or vertebral osteomyelitis, lumbar epidural abscesses generally can be drained through a posterior approach.  Delayed stabilization usually is not required unless, in the course of decompression, removal of too much of the facets creates an instability; this is an uncommon occurrence.

 

REFERENCES: Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 257-271.

Reihsaus E, Waldbaur H, Seeling W: Spinal epidural abscess: A meta-analysis of 915 patients.  Neurosurg Rev 2000;23:175-204.

 

 

 

 

88.       A 25-year-old man has chronic back pain that has been slowly worsening.  He has no constitutional symptoms, and he denies any previous medical problems.  Examination shows a tall lean build with no objective neurologic findings or skin lesions.  Figure 32 shows a T2-weighted sagittal MRI scan.  What is the most likely diagnosis?

 

1-         Marfan syndrome

2-         Ankylosing spondylitis

3-         Lumbar disk herniation

4-         Arnold-Chiari malformation

5-         Ehlers-Danlos syndrome

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The MRI scan shows significant dural ectasia, which is seen in more than 60% of patients with Marfan syndrome.  It is also relatively common in patients with neurofibromatosis, but this patient has no skin lesions.  It has also been described in Ehlers-Danlos syndrome but is less common.

 

REFERENCES: Ahn NU, Sponseller PD, Ahn UM, Nallamshetty L, Kuszyk BS, Zinreich SJ: Dural ectasia is associated with back pain in Marfan’ syndrome.  Spine 2000;25:1562-1568.

Villeirs GM, Van Tongerloo AJ, Verstraete KL, Kunnen MF, De Paepe AM: Widening of the spinal canal and dural ectasia in Marfan’s syndrome: Assessment by CT.  Neuroradiology 1999;41:850-854.

 

 

 

 

89.       Which of the following factors has the most effect on the pullout strength of lumbar transpedicular screw fixation?

 

1-         Depth of vertebral body penetration

2-         Screw diameter

3-         Percentage of pedicle filled by the screw

4-         Presence of osteopenia

5-         Tapping of the pedicle

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Although all of the factors listed contribute to the pullout strength of transpedicular screw fixation, low bone density generally is felt to be the most influential.

 

REFERENCES: Wittenberg RH, Shea M, Swartz DE, Lee KS, White AA III, Hayes WC: Importance of bone mineral density in instrumented spine fusions.  Spine 1991;16:647-652.

Zindrick MR, Wiltse LL, Widell EH, et al: A biomechanical study of intrapeduncular screw fixation in the lumbosacral spine.  Clin Orthop 1986;203:99-112.

 

 

 

 

90.       Examination of a 34-year-old man who has had left leg pain for the past 6 weeks reveals minimal weakness of the left extensor hallucis longus and normal ankle jerk and patellar reflexes.  Figure 33 shows an axial MRI scan of the L4-5 disk.  Based on these findings, the MRI scan results are consistent with compression of the

 

1-         traversing L4 nerve root and the patient’s history and examination.

2-         traversing L4 nerve root but inconsistent with the patient’s history and examination.

3-         traversing L5 nerve root and the patient’s history and examination.

4-         traversing L5 nerve root but inconsistent with the patient’s history and examination.

5-         exiting L5 nerve root and the patient’s history and examination.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The patient has an L5 radiculopathy secondary to an L4-5 disk herniation that is compressing the traversing L5 nerve root.

 

REFERENCE: McCulloch JA, Young PH: Essentials of Spinal Microsurgery.  Philadelphia, PA, Lippincott-Raven, 1998.

 

 

 

 

91.       A 20-year-old college athlete is seen for follow-up after sustaining an injury at football practice 2 days ago.  He reports that he tackled a player and felt neck pain and numbness in both arms.  The numbness resolved within seconds, but his neck remains painful and stiff.  He denies any history of neck pain or injury.  Examination reveals limited neck motion.  The neurologic examination and radiographs are normal.  MRI scans of the cervical spine are shown in Figure 34.  During counseling, the patient, his family, and his coach should be informed that he has an acute cervical disk herniation and cannot play

 

1-         until his symptoms resolve and the MRI findings return to normal.

2-         until his symptoms resolve and his physical examination findings return to normal.

3-         until he undergoes surgical decompression.

4-         until he undergoes surgical decompression and fusion.

5-         again because it is considered a career-ending injury.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: A player who has an acute cervical disk herniation should not be allowed to return to play until the acute phase is over.  Certain players with large herniations may require surgery before returning to play to eliminate the risk of disk-related stenosis and cord compression.

 

REFERENCES: Morganti C, Sweeney CA, Albanese SA, Burak C, Hosea T, Connolly PJ: Return to play after cervical spine injury.  Spine 2001;26:1131-1136.

Vaccaro AR, Watkins B, Albert TJ, Pfaff WL, Klein GR, Silber JS: Cervical spine injuries in athletes: Current return-to-play criteria.  Orthopedics 2001;24:699-705.

 

 

 

 

92.       An Asian 45-year-old man has bilateral upper extremity dysfunction. Figure 35a shows a T2-weighted sagittal MRI scan of the cervical spine, and Figure 35b shows a T2-weighted axial MRI scan at the level of the C3 vertebral body.  What is the most likely pathologic process?

 

1-         Cervical spondylosis

2-         Diffuse idiopathic skeletal hyperostosis (DISH)

3-         Ossification of the posterior longitudinal ligament (OPLL)

4-         Ankylosing spondylitis

5-         Neurofibromatosis

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Although relatively common in people of Asian origin, OPLL has been reported in other races as well.  The radiographic appearance can be variable as there are different types described, but some of the discerning characteristics are seen in these images.  On the sagittal view, the bone posterior to the vertebral body extends along the entire length of C2 and C3.  This is characteristic of OPLL, whereas cervical spondylosis and DISH more commonly are not confluent.  Ankylosing spondylitis more commonly extends significantly into the spinal canal, and neurofibromatosis generally does not cause any bony growth.  The axial view shows a large, oval bony projection into the spinal canal, a typical finding of OPLL.

 

REFERENCES: McAfee PC, Regan JJ, Bohlman HH: Cervical cord compression from ossification of the posterior longitudinal ligament in non-orientals.  J Bone Joint Surg Br 1987;69:569-575.

Kricun R, Kricun ME: MRI and CT of the Spine.  New York, NY, Raven Press, 1994,
pp 126-130.

 

 

 

 

93.       A 36-year-old man has a moderate-sized left paracentral L5-S1 disk herniation with compression of the S1 nerve.  Examination will most likely reveal sensory changes at what location?

 

1-         Anterior thigh stopping at the knee

2-         Lateral border of the foot

3-         Dorsum of the foot and the great toe

4-         Medial side of the leg

5-         Perianal region

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Because the left paracentral L5-S1 disk herniation is compressing the left S1 nerve root, the patient will have numbness along the lateral border and plantar surface of the foot.  Numbness along the anterior thigh stopping at the knee is consistent with an L3 radiculopathy.  Sensory changes at the dorsum of the foot and great toe normally signify an L5 distribution; the medial leg signifies an L4 distribution.  Perianal numbness involves the S2-S5 nerve roots.

 

REFERENCES: Wisneski RJ, Garfin SR, Rothman RH, Lutz GE: Lumbar disk disease, in Herkowitz HN, Garfin SR, Balderston RA, Eismont FJ, Bell GR, Wiesel SW (eds): Rothman and Simeone The Spine, ed 4.  Philadelphia, PA, WB Saunders, 1999, vol 1, pp 629-634.

Hoppenfeld S: Physical Examination of the Spine and Extremities.  Norwalk, CT, Appleton- Century-Crofts, 1976, pp 249-254.

 

 

 

 

94.       In a patient with a C5-6 herniation, the most likely sensory deficit will be in the

 

1-         lateral shoulder.

2-         radial forearm, thumb, and index finger.

3-         dorsal forearm and middle finger.

4-         ulnar forearm, ring finger, and little finger.

5-         volar forearm and palm.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: A C5-6 herniation compresses the C6 root, which innervates the radial forearm, thumb, and index finger.  The lateral shoulder is innervated by C5.  The dorsal forearm and the middle finger typically are innervated by C7.  The ulnar forearm, ring finger, and little finger are innervated by C8.  There is no specific nerve associated with the volar forearm and palm. 

 

REFERENCE: Hoppenfeld S: Evaluation of nerve root lesions involving the upper extremity, in Orthopaedic Neurology.  Philadelphia, PA, JB Lippincott, 1977, pp 7-23.

 

 

 

 

95.       A 78-year-old woman has had activity-limiting cervical pain and occipital headaches for the past 4 years.  Management consisting of injections, analgesics, and part-time collar wear has provided temporary relief.  Examination reveals that her neck pain seems to be primarily located immediately below the skull and is aggravated by long periods of sitting and rotation of her head.  Plain radiographs are shown in Figures 36a through 36c.  What is the best course of action?

 

1-         Posterior atlantoaxial arthrodesis

2-         Placement of a dens screw

3-         Arthrodesis from the posterior occiput to C2

4-         Continued nonsurgical management

5-         Anterior cervical diskectomy and fusion at C2-3

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Posterior atlantoaxial arthrodesis predictably relieves pain associated with arthrosis of the atlantoaxial joints.  Typically, these patients have pain at the base of the occiput and in the most cephalad portion of the posterior aspect of the neck.  Associated headache is common and often severe.  Pain is aggravated by rotation but usually not by flexion and extension.  Diagnostic blocks of the C1-C2 joint and the greater occipital nerve may be helpful to confirm the diagnosis preoperatively.

 

REFERENCES: Ghanayem AJ, Leventhal M, Bohlman HH: Osteoarthrosis of the atlanto-axial joints: Long-term follow-up after treatment with arthrodesis.  J Bone Joint Surg Am 1996;78:1300-1307.

Star MJ, Curd JG, Thorne RP: Atlantoaxial lateral mass osteoarthritis: A frequently overlooked cause of severe occipitocervical pain.  Spine 1992;17:S71-S76.

 

96.       Contraindications to cervical laminectomy as a treatment for cervical spondylotic myelopathy include which of the following findings?

 

1-         Multilevel disease with spinal cord compression

2-         Anterior spinal cord compression

3-         Posterior spinal cord compression

4-         Cervical kyphosis

5-         Ossification of the posterior longitudinal ligament

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Cervical laminectomy is an accepted treatment for multilevel cervical spondylotic myelopathy.  When the compression is posterior, laminectomy addresses it directly; when the compression is anterior, it is addressed indirectly (the spinal cord floats posteriorly away from the anterior compression).  Preexisting kyphosis is a contraindication to laminectomy because the cord is unable to float posteriorly away from the anterior compression, and the risk for increasing kyphosis is significant.  Kyphosis after laminectomy is more likely to develop in younger patients who have fewer degenerative changes to stabilize the spine.

 

REFERENCES: Malone DG, Benzyl EC: Laminotomy and laminectomy for spinal stenosis causing radiculopathy or myelopathy, in Clark CR (ed.): The Cervical Spine, ed 3.  Philadelphia, PA, Lippincott Raven, 1998, pp 817-825.

Beaty JH (ed): Orthopaedic Knowledge Update 6.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1999, pp 673-680.

 

97.       What arterial vessel is most prone to injury during posterior iliac crest bone graft harvest?

 

1-         Superior gluteal

2-         Deep circumflex iliac

3-         Iliolumbar

4-         Ascending branch of the lateral femoral circumflex

5-         Fourth lumbar

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The superior gluteal artery is most at risk with a posterior iliac crest bone graft harvest.  The artery leaves the pelvis through the sciatic notch and can be injured by retractors or other sharp instruments entering the sciatic notch area.  The deep circumflex iliac, iliolumbar, and fourth lumbar arteries supply the iliacus and iliopsoas muscles and can be damaged during anterior bone graft harvest.  The ascending branch of the lateral femoral circumflex artery is at risk during the anterior approach to the hip.

 

REFERENCES: Guyer RD, Delmarter RB, Fulp T, Small SD: Complications of cervical spine surgery, in Herkowitz HN, Garfin SR, Balderston RA, Eismont FJ, Bell GR, Wiesel SW (eds): Rothman-Simeone The Spine, ed 4.  Philadelphia, PA, WB Saunders, 1999, p 547.

Kurz LT, Garfin SR, Booth RE Jr: Iliac bone grafting: Techniques and complications of harvesting, in Garfin SR (ed): Complications of Spine Surgery.  Baltimore, MD, Williams and Wilkins, 1989, pp 330-331.

Hoppenfeld S, deBoer P: Surgical Exposures in Orthopaedics: The Anatomic Approach.  Philadelphia, PA, JB Lippincott, 1984, pp 297, 331-332.

 

 

 

 

98.       A 30-year-old man who underwent an anterior lumbar diskectomy and fusion at L4-5 and L5-S1 through an anterior retroperitoneal approach 1 month ago now reports he is unable to obtain and maintain an erection.  The most likely cause of this condition is

 

1-         disruption of the sympathetic nerves during anterior lumbar exposure.

2-         traction on the parasympathetic nerve at the L4-5 level.

3-         not related to the surgical dissection.

4-         injury to the pudendal nerves in the anterior sacral region during dissection at the L5-S1 level.

5-         sexual dysfunction secondary to retrograde ejaculation.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Sexual dysfunction is a common condition after extensive anterior lumbar surgical dissection.  Erectile dysfunction usually is nonorganic but may be related to parasympathetic injury.  The parasympathetic nerves are deep in the pelvis at the level of S2-3 and S3-4 and usually are not involved in the surgical field for anterior L4-5 and L5-S1 procedures.  Retrograde ejaculation is the result of injury to the sympathetic chain on the anterior surface of the major vessels crossing the L4-5 level and at the L5-S1 interspace.  Erectile function and orgasm are not affected by sympathetic injury.  The pudendal nerve is primarily a somatic nerve and is not located in the surgical field.

 

REFERENCES: Flynn JC, Price CT: Sexual complications of anterior fusion of the lumbar spine.  Spine 1984;9:489-492.

Johnson RM, McGuire EJ: Urogenital complications of anterior approaches to the lumbar spine.  Clin Orthop 1981;154:114-118.

 

 

 

 

99.       Which of the following statements about injury of the anterior vascular structures during lumbar disk surgery is true? 

 

1-         An arteriovenous fistula formation is more likely to form than acute, life-threatening bleeding.

2-         The L5-S1 level is the most common site.

3-         Use of a curette in the disk space is the most common cause.

4-         It is rarely associated with patient death.

5-         Brisk bleeding from the disk space always occurs as a result.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Vascular injury most commonly occurs at L4-L5, followed by L5-S1 and are associated with use of the pituitary rongeur.  Hohf reported that 17 of 58 patients died as a result.  Early recognition and treatment of this complication is vital; unfortunately, intraoperative bleeding from the disk space may occur in up to 50% of these patients.  Some may be first recognized in the recovery room.  Common clinical findings include hypotension, tachycardia, and a rigid abdomen.  Formation of an arteriovenous fistula is the most common vascular injury resulting from lumbar disk surgery but is usually not recognized until months after surgery.  Cardiomegaly and high output cardiac failure are common presenting symptoms.

 

REFERENCES: Hohf RP: Arterial injuries occurring during orthopaedic operations.  Clin Orthop 1963;28:21-37.

Montorsi W, Ghiringhelli C: Genesis, diagnosis and treatment of vascular complications after intervertebral disk surgery.  Int Surg 1973;58:233-235.

Stambough JL, Simeone FA: Vascular complications in spine surgery, in Garfin SR (ed): Complications of Spine Surgery.  Baltimore, MD, Williams and Wilkins, 1989, pp 323-341.

 

 

 

 

100.   The photomicrograph in Figure 37 shows a repaired dural tear 4 days after surgery.  The material interposed between the dural edges (D) is composed of

 

1-         fibroblasts.

2-         dural remnants.

3-         pia-arachnoid membrane.

4-         scar tissue.

5-         neural elements.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: During the initial healing phases of a dural tear, pia and arachnoid from adjacent nerve roots migrate, fill the dural defect, and create a pia-arachnoid plug.  It is this initial plugging of the defect that is believed to prevent further egress of cerebrospinal fluid through the defect.  The plug has been shown to develop by the second postoperative day.  Fibroblastic proliferation occurs within the dura itself and accounts for the bulbous ends of the dura seen in the photomicrograph.  The appearance of the material within the dural edges is inconsistent with the appearance of neural elements, and scar tissue formation occurs later in the healing process.

 

REFERENCES: Cain JE Jr, Dryer RF, Barton BR: Evaluation of dural closure techniques: Suture methods, fibrin adhesive sealant, and cyanoacrylate polymer.  Spine 1988;13:720-725.

Cain JE Jr, Lauerman WC, Rosenthal HG, Broom MJ, Jacobs RR: The histomorphologic sequence of dural repair: Observations in the canine model.  Spine 1991;16:S319-S323.

 

 

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