ORTHOPEDIC MCQS WITH ANSWERS ONLINE SPINE 06

 

1.      Figures 1a and 1b show the sagittal T₂- and T₁-weighted MRI scans of a 25-year-old intravenous drug abuser who has low back pain that is increasing in intensity.  Laboratory studies show a WBC count of 10,000/mm³ and an erythrocyte sedimentation rate of
80 mm/h.  Blood culture is negative. Initial management consist of

 

1-         CT-guided closed biopsy.

2-         open surgical biopsy.

3-         antibiotic coverage for Staphylococcus aureus.

4-         broad-spectrum antibiotic coverage.

5-         a follow-up MRI scan in 8 weeks.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The MRI scans show vertebral diskitis/osteomyelitis.  The treatment of spinal infection in adults should be organism specific; therefore, initial management should consist of CT-guided closed biopsy prior to administration of antibiotic coverage.  An open biopsy is indicated for a failed closed biopsy or failure of nonsurgical management.  Although Staphylococcus aureus is the most common bacteria, a history of intravenous drug abuse raises suspicion for other organisms, including Pseudomonas.

 

REFERENCES: Tay BK, Deckey J, Hu SS: Spinal Infections.  J Am Acad Orthop Surg 2002;10:188-197.

Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 431-439.

 

2.      A 27-year-old man sustained a gunshot wound to the lumbar spine and undergoes an exploratory laparotomy.  An injury to the cecum is identified and treated.  Management should now include

 

1-         no antibiotics.

2-         oral broad-spectrum antibiotics for 7 days.

3-         intravenous broad-spectrum antibiotics for 48 hours.

4-         intravenous broad-spectrum antibiotics for 7 days.

5-         intravenous antibiotics specific for Staphylococcus for 7 days.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Gunshot wounds to the spine present relatively little risk of infection in most cases.  When there has been an injury to the colon, the risk of infection can be minimized with
a 7-day course of broad-spectrum antibiotics.  Fragment removal is not indicated.

 

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.

 

3.      A 68-year-old man reports a 1-year history of debilitating neck pain without neurologic symptoms.  History reveals a C5-6 anterior diskectomy and bone grafting 10 years ago that provided good relief of arm and neck pain.  Radiographs show evidence of fibrous union at C5-6, spondylotic disk narrowing at C4-5 and C6-7, and a fixed 2-mm subluxation at C3-4.  Examination reveals cervical stiffness and discomfort at the extremes of movement.  His neurologic examination is normal.  Treatment should now consist of

 

1-         posterior fusion at C3-C7.

2-         anterior fusion at C3-7 with plate fixation through the same scar.

3-         anterior fusion at C3-7 with plate fixation through a right-sided incision.

4-         an epidural steroid injection.

5-         patient education, exercise, and nonnarcotic medication.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Axial pain can be difficult to manage.  Pain management is not always successful, and surgical approaches may provide disappointing results unless there is discrete pathology.  Whereas planning of a surgical approach should consider prior approaches and preexisting laryngeal dysfunction, no compelling case for surgical intervention can be made for this patient.  Therefore, management should consist of patient education, exercise, and nonnarcotic medication.

 

REFERENCES: Ahn NU, Ahn UM, Andersson GB, et al: Operative treatment of the patient with neck pain.  Phys Med Rehabil Clin N Am 2003;14:675-692.

Algers G, Pettersson K, Hildingsson C, et al: Surgery for chronic symptoms after whiplash injury: Follow-up of 20 cases.  Acta Orthop Scand 1993;64:654-656.

Rao R: Neck pain, cervical radiculopathy, and cervical myelopathy: Pathophysiology, natural history, and clinical evaluation.  Instr Course Lect 2003;52:479-488.

 

4.      Which of the following is considered the lowest level that a standard thoracolumbosacral orthosis (TLSO) can immobilize?

 

1-         L1-2

2-         L3-4

3-         L5-S1

4-         T9-10

5-         T11-12

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Without more distal immobilization such as a thigh extension, the lower two lumbar segments generally show the same or even increased mobility with a TLSO.

 

REFERENCES: White AA, Panjabi MM: Clinical Biomechanics of the Spine, ed 2.  Philadelphia, PA, JB Lippincott, 1990, pp 475-509.

Norton PL, Brown T: The immobilizing efficiency of back braces.  J Bone Joint Surg Am 1957;39:111-139.

 

5.      A 65-year-old man with ankylosing spondylitis has neck pain after falling back over his lawnmower, striking his thoracic spine, and forcing his neck into extension.  Examination reveals subtle weakness of the intrinsics and finger flexors at approximately 4+/5.  Initial management consists of immobilization in a rigid collar, and placing his head in the anatomic position.  Radiographs reveal a subtle extension fracture of the lower cervical spine.  Approximately 6 hours after the injury, he reports increasing paresthesias in his upper and lower extremities, and examination now shows his intrinsics are 2/5, finger flexors are 3/5, and his triceps are now weak at 4/5 on manual motor testing.  In addition, his lower extremities now show weakness in both dorsal and plantar flexion of the ankle in the range of 4/5.  Repeat radiographs appear unchanged.  An MRI scan is shown in Figure 2.  Management should now consist of

 

1-         methylprednisolone and observation.

2-         posterior laminectomy and spinal fusion.

3-         anterior spinal fusion.

4-         halo vest immobilization.

5-         posterior laminectomy followed by halo vest immobilization.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: It is not uncommon for patients with ankylosing spondylitis to sustain extension-type fractures, most typically of the cervicothoracic junction.  These fractures can appear nondisplaced or minimally displaced initially, making them difficult to diagnose.  Because there is no mobility between vertebrae, fractures tend to occur more like those of a transverse fracture of a long bone.  In addition, the vertebral bodies are vascular and their canals are relatively enclosed, making them vulnerable to epidural bleeding.  The MRI scan reveals an epidural hematoma located posteriorly on the cord; therefore, the treatment of choice is surgical evacuation and a posterior laminectomy.  Because of the intrinsic instability of such fractures at the time of the laminectomy, internal fixation and stabilization with a posterior fusion is warranted.  A simple laminectomy will only increase instability, and control is unlikely with halo vest immobilization.  An anterior procedure will not effectively treat the problem given the location of the hematoma.  Consideration can be given to methylprednisolone and observation; however, this will not eradicate the problem.

 

REFERENCES: Bohlman HH: Acute fractures and dislocations of the cervical spine.  J Bone Joint Surg Am 1979;61:1119-1142.

Weinstein PR, Karpman RR, Gall EP, et al: Spinal cord injury, spine fracture and spinal stenosis in ankylosing spondylitis.  J Neurosurg 1982;57:609-616.

 

6.      Figures 3a and 3b show the MRI scans of a patient with neck pain.  What is the most likely diagnosis?

 

1-         Neurofibromatosis

2-         Multiple sclerosis

3-         Cervical spondylotic myelopathy

4-         Acute poliomyelitis

5-         Gaucher’s disease

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Muliple neurofibromas result in marked foraminal enlargement as seen on the sagittal MRI scan. Collagen disorders leading to dural ectasia may show similar enlargement, but none of these is listed as a possible answer.

 

REFERENCES: Kim HW, Weinstein SL: Spine update: The management of scoliosis in neurofibromatosis.  Spine 1997;22:2770-2776.

Funasaki H, Winter RB, Lonstein JB, et al: Pathophysiology of spinal deformities in neurofibromatosis: An analysis of seventy-one patients who had curves associated with dystrophic changes.  J Bone Joint Surg Am 1994;76:692-700.

 

7.      A Trendelenburg gait is most likely to be seen in association with

 

1-         a central disk herniation at L3-L4.

2-         an ipsilateral paracentral disk herniation at L3-L4.

3-         an ipsilateral paracentral disk herniation at L4-L5.

4-         an ipsilateral paracentral disk herniation at L5-S1.

5-         an ipsilateral far lateral disk herniation at L4-L5.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: A Trendelenburg gait results from weakness of the gluteus medius, which is innervated by the L5 nerve root.  A paracentral disk herniation at L4-L5 most commonly results in an L5 radiculopathy and thus weakness of the gluteus medius.  A paracentral herniation at L5-S1 most commonly affects the S1 nerve root.  A paracentral herniation at L3-L4, a central herniation at L3-L4, and a far lateral herniation at L4-L5 all affect the L4 root.

 

REFERENCES: Fardon DF, Garfin SR, Abitbol J, et al (eds): Orthopedic Knowledge Update: Spine 2.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 323-332.

Andersson GB, Deyo RA: History and physical examination in patients with herniated lumbar discs.  Spine 1996;21:10S-18S.

 

8.      An otherwise healthy 70-year-old man has back and bilateral leg pain in an L5 distribution that is aggravated by standing more than 10 minutes or walking more than 100 feet.  He has to sit to get relief.  Neurologic and pulse examinations are normal.  A radiograph and MRI scan are shown in Figures 4a and 4b.  Treatment should consist of

 

1-         laminectomy.

2-         hemilaminectomy.

3-         laminectomy and posterolateral fusion.

4-         anterior interbody fusion.

5-         posterolateral fusion.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The patient has a degenerative spondylolisthesis at L4-5 with associated spinal stenosis.  His symptoms are consistent with neurogenic claudication.  Based on these findings, the surgical treatment of choice is decompression and posterolateral fusion.  Use of instrumentation is controversial.  Laminectomy alone is reserved for the patient who is frail medically.  There is no role for an anterior approach or for fusion alone without decompression.

 

REFERENCES: Fischgrund JS, Mackay M, Herkowitz HN, et al: Degenerative lumbar spondylolisthesis with spinal stenosis: A prospective, randomized study comparing decompressive laminectomy and arthrodesis with and without spinal instrumentation.  Spine 1997;22:2807-2812.

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.

 

9.      Figures 5a and 5b show the radiograph and MRI scan of a patient who has severe mechanical neck pain but no neurologic problems.  Biopsy and work-up show the lesion to be a solitary plasmacytoma.  Treatment should consist of

 

1-         radiation therapy alone.

2-         en bloc resection and anterior fusion.

3-         chemotherapy and bone marrow transplant.

4-         posterior occipitocervical fusion and radiation therapy.

5-         en bloc anterior resection followed by posterior occipitocervical fusion.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Plasmacytoma is very sensitive to radiation therapy and given the complexity of the resection and complications of surgery in the given location, radiation therapy is preferred.  However, the patient has clear loss of bony structural integrity, and resultant instability would persist even with tumor irradiation; therefore, posterior stabilization is warranted.  Chemotherapy and bone marrow transplant are reserved for systemic disease with multiple myeloma.

 

REFERENCES: Corwin J, Lindberg RD: Solitary plasmacytoma of bone vs. extramedullary plasmacytoma and their relationship to multiple myeloma.  Cancer 1979;43:1007-1013.

Durr HR, Wegener B, Krodel A, et al: Multiple myeloma: Surgery of the spine.  Retrospective analysis of 27 patients.  Spine 2002;27:320-324.

 

10.    A 71-year-old woman undergoes a posterior lumbar decompression and fusion from L4-S1.  Thirty-six hours after the procedure, she reports severe right-sided chest pain and shortness of breath.  Doppler ultrasound reveals a clot proximal to the knee within the femoral vein.  A large pulmonary embolus is confirmed by CT angiography.  The next most appropriate step in management should consist of

 

1-         pneumatic compression stockings.

2-         subcutaneous heparin administration.

3-         a heparin bolus followed by therapeutic heparin anticoagulation.

4-         warfarin anticoagulation.

5-         placement of a vena cava filter.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: In a review of 13,000 spinal procedures, nine patients were treated with heparin following development of pulmonary emboli.  Of these patients, six had serious complications ranging from wound drainage to paralysis.  Heparin therapy instituted within 10 days of the surgical procedure resulted in a 100% complication rate.  Vena cava filter placement has a complication rate of 0.12% to 10.1%.  Removable filters are currently in clinical trials.

 

REFERENCES: Cain JE Jr, Major MR, Lauerman WC, et al: The morbidity of heparin therapy after development of pulmonary embolus in patients undergoing thoracolumbar or lumbar spinal fusion.  Spine 1995;20:1600-1603.

Roberts AC: Venous imaging and inferior vena cava filters.  Curr Opin Radiol 1992;4:88-96.

Becker DM, Philbrick JT, Selby JB: Inferior vena cava filters.  Arch Intern Med

1992;152:1985-1994.

 

11.     Figure 6 shows the lateral radiograph of a 22-year-old woman who has painful Scheuermanns’s kyphosis in the middle and lower thoracic spine.  When planning surgical correction using instrumentation, the distal aspect of the instrumentation should ideally extend to the

 

1-         first lordotic segment of the lumbar spine.

2-         distal aspect of the curve as measured by the Cobb technique.

3-         lower thoracic spine.

4-         lower lumbar spine.

5-         sacrum.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Posterior constructs for Scheuermann’s kyphosis ideally should extend from the most superior to the most inferior aspect of the Cobb angulation.  However, the most distal fusion level must be in a stable or lordotic position to avoid the development of junctional kyphosis.  Lowe reported that failure to incorporate the first lordotic segment of the lumbar spine is associated with a higher risk of junctional kyphosis.  The first lordotic segment of the lumbar spine is typically at least one level below the distal aspect of the curve as measured by the Cobb technique and most commonly is in the upper part of the lumbar spine.

 

REFERENCES: Lowe TG: Scheuermann’s disease.  Orthop Clin North Am 1999;30:475-487.

Lenke LG: Kyphosis of the thoracic and thoracolumbar spine in the pediatric patients: Prevention and treatment of surgical complications.  Instr Course Lect 2004;53:501-510.

 

12.     Figure 7 shows the radiograph of a 64-year-old man who has neck pain and weakness of the upper and lower extremities following a motor vehicle accident.  Examination reveals 3/5 quadriceps and 4/5 hip flexors but no ankle dorsiflexion or plantar flexion.  His intrinsics are 1/5, with finger flexors of 3/5.  He is awake, alert, and cooperative.  Management should consist of

 

1-         halo vest immobilization.

2-         MRI.

3-         Gardner-Wells tongs and closed reduction.

4-         posterior open reduction and fusion.

5-         observation until the patient’s general medical status improves, followed by closed reduction via Gardner-Wells tongs.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: In patients with facet dislocations and an incomplete neurologic deficit, early decompression of the canal via reduction of the dislocation generally is considered safe if the patient is alert and can cooperate.  However, patients who cannot cooperate with serial neurologic examinations during the reduction are at risk for increased deficit secondary to herniated nucleus pulposus, and MRI should be performed prior to either closed or

open reduction.

 

REFERENCES: Star AM, Jones AA, Cotler JM, et al: Immediate closed reduction of cervical spine dislocations using traction.  Spine 1990;15:1068-1072.

Cotler JM, Herbison GJ, Nasuti JF, et al: Closed reduction of traumatic cervical spine dislocations using traction weight up to 140 pounds.  Spine 1993;18:386-390.

 

13.     What is the recommended insertion torque for halo pins in adults?

 

1-         4 in-lb

2-         5 in-lb

3-         6 in-lb

4-         8 in-lb

5-         10 in-lb

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Garfin and associates have shown that halo pins inserted with 8 in-lb of insertion torque results in significantly less loosening with cyclical loading than pins inserted with 6 in-lb of torque.  Moreover, Botte and associates reported that 8 in-lb of torque is clinically safe and effective in lowering the incidence of pin loosening and infection. 

 

REFERENCES: Botte MJ, Byrne TP, Garfin SR: Application of the halo device for immobilization of the cervical spine utilizing an increased torque pressure.  J Bone Joint Surg Am 1987;69:750-752. 

Garfin SR, Lee TO, Roux RD, et al: Structural behavior of the halo orthosis pin-bone interface: Biomechanical evaluation of standard and newly designed stainless steel halo fixation pins.  Spine 1986;11:977-981. 

Vaccaro AR, Botte MD, Bengt IL, et al: Cervical orthotics including traction and halo devices, in Clark CR (ed): The Cervical Spine, ed 3.  Philadelphia, PA, Lippincott Raven, 1998, pp 113-140.

 

14.     A 55-year-old woman with a history of untreated idiopathic scoliosis has had neurogenic claudication for the past several months.  MRI reveals spinal stenosis at L2-L3, L3-L4, and L4-L5.  Radiographs show a 45° lumbar curve from T10 to L4, with a degenerative spondylolisthesis at L4-L5.  Laminectomy at the stenotic levels and stabilization of the deformity are planned.  Which of the following is NOT considered an absolute indication for extending the fusion to the sacrum, rather than stopping at L5?

 

1-         Advanced degenerative disk disease with facet arthrosis at L5-S1

2-         Decreased T2 signal in the L5-S1 disk with normal facet joints

3-         Previous laminectomy at L5-S1

4-         Fixed tilt of L5 with severe unilateral facet arthrosis

5-         Spondylolysis bilaterally at L5

 

PREFERRED RESPONSE: 2

 

DISCUSSION: There are several indications for extending adult scoliosis fusions to the sacrum, rather than stopping in the lower lumbar spine.  These indications include posterior column deficiencies at L5-S1, such as spondylolysis and laminectomy, and deformities extending to the sacrum, such as fixed tilt of L5-S1 or sagittal imbalance.  MRI signal changes in the L5-S1 disk do not preclude stopping the fusion at L5.  Some surgeons use diskography or diagnostic facet blocks to evaluate the integrity of the L5-S1 level prior to stopping the fusion at L5.  Long scoliosis fusions stopping at L5 have a significant risk of failure, highlighting the importance of careful selection of fusion levels.

 

REFERENCES: Bradford DS, Tay BK, Hu SS: Adult scoliosis: Surgical indications, operative management, complications, and outcomes.  Spine 1999;24:2617-2629.   

Bridwell KH: Where to stop the fusion distally in adult scoliosis: L4, L5, or the sacrum?  Instr Course Lect 1996;45:101-107.

Edwards CC II, Bridwell KH, Patel A, et al: Long adult deformity fusions to L5 and the sacrum: A matched cohort analysis.  Spine 2004;29:1996-2005.

 

15.     Which of the following findings is considered a contraindication for posterior decompression (with or without fusion) for myelopathy?

 

1-         Subluxation of more than 3.5 mm at one or more motion segments

2-         Dynamic angulation of more than 11° at one or more motion segments

3-         Subaxial cervical lordosis of more than 25° (as measured from C2 to C7)

4-         Fixed kyphosis of more than 10°

5-         Anteroposterior spinal canal diameter of less than 8 mm

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Although cervical instability is a contraindication to posterior decompression alone, segmental instability in the myelopathic cervical spine can be addressed with concomitant posterior fusion with instrumentation.  Cervical lordosis represents the ideal scenario for posterior decompressive procedures for myelopathy (laminectomy and laminoplasty) because compression from anterior osteophytes, if present, is relieved as the spinal cord migrates posteriorly.  The anteroposterior diameter of the spinal canal does not have an impact on the selection of surgical approach.  Posterior unroofing-type procedures in kyphotic cervical spines, however, are ineffective because anterior impingement on the spinal cord will remain; therefore, kyphosis of more than 10° is considered a contraindication for posterior decompression.

 

REFERENCES: Emery SE: Cervical spondylotic myelopathy: Diagnosis and treatment.  J Am Acad Orthop Surg 2001;9:376-388.

Malone DG, Benzel 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 817-823.

 

16.     A patient reports progessive bilateral hand clumsiness and ataxia.  Examination reveals a positive Hoffmann’s sign and intrinsic atrophy.  MRI reveals multilevel cervical spondylosis, and lateral flexion and extension radiographs show cervical kyphosis in the neutral position, with restoration of lordosis on extension.  Which of the following procedures is most likely to result in poor long-term results?

 

1-         Multilevel anterior cervical diskectomy with fusion

2-         Anterior and posterior decompression with fusion

3-         Anterior corpectomy and fusion with a fibula strut

4-         Laminectomy and bilateral foraminotomies

5-         Laminectomy and posterior fusion with lateral mass plating

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Adequate decompression of the cervical cord can be achieved in a variety of ways depending on the pathoanatomy of the compression, but kyphosis is a relative contraindication to laminectomy alone.  For laminectomy to be effective, the lordosis must be maintained so the cord can displace posteriorly away from the anterior structures.  In addition, removing the posterior tension band increases the probability that the kyphosis will progress, therefore increasing the force against the front of the cord as it tents across the kyphosis.

 

REFERENCES: Albert TJ, Vaccaro A: Postlaminectomy kyphosis.  Spine 1998;23:2738-2745.

Truumees E, Herkowitz HN: Cervical spondylotic myelopathy and radiculopthy.  Instr Course Lect 2000;49:339-360.

Emery SE: Cervical spondylotic myelopathy: Diagnosis and treatment.  J Am Acad Orthop Surg 2001;9:376-388.

 

17.    A 45-year-old man seen in the emergency department reports a 1-week history of worsening low back pain and a progressive neurologic deficit in the S1 distribution.  Examination reveals 2/5 strength in the gastrocnemius.  Laboratory studies show a WBC count of 13,500/mm³ and an erythrocyte sedimentation rate of 74 mm/h.  Radiographs of the lumbosacral spine show narrowing of the L5-S1 disk space, with irregularity of the end plates. A sagittal T₂-weighted MRI scan is shown in Figure 8.  Definitive management should consist of

 

1-         physical therapy that includes a program of centralization of his leg pain.

2-         a thoracolumbosacral brace to include one thigh.

3-         L5-S1 laminectomy.

4-         interbody cage fusion with allograft bone.

5-         anterior debridement and decompression with posterior stabilization.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The history, physical examination, laboratory, and radiographic findings are most consistent with an infectious process.  When there are signs of neurologic compromise, surgery is generally recommended.  This is an anterior process, and anterior column debridement is necessary, followed by stabilization.  Anterior or posterior stabilization is a reasonable option, but posterior decompression alone is unlikely to adequately reverse the process and may lead to segmental kyphosis.

 

REFERENCES: Frymoyer JW, Wiesel SW (eds): The Adult and Pediatric Spine, ed 3.  Philadelphia, PA, Lippincott Williams and Wilkins, 2003, pp 165-189.

Modic MT, Feiglin DH, Piraino DW, et al: Vertebral osteomyelitis: Assessment using MR.  Radiology 1985;157;157-166.

 

18.    In a retroperitoneal approach to the lumbar spine, what structure runs along the medial aspect of the psoas and along the lateral border of the spine?

 

1-         Ilioinguinal nerve

2-         Genitofemoral nerve

3-         Sympathetic trunk

4-         Ureter

5-         Aorta

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The sympathetic trunk runs longitudinally along the medial border of the psoas.  The ilioinguinal nerve emerges along the upper lateral border of the psoas and travels to the quadratus lumborium, and the genitofemoral nerve lies more laterally on the psoas.  The ureter is adherent to the posterior peritoneum and falls away from the psoas and the spine in the dissection, as does the aorta.

 

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

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

 

19.    What is the most likely primary cause of decreased success rates of bony fusion in smokers undergoing lumbar arthrodesis?

 

1-         Chronic obstructive pulmonary disease

2-         Inhibition of bone formation by nicotine

3-         Poor compliance with postoperative treatment recommendations

4-         Lower general nutritional status

5-         Peripheral vascular disease

 

PREFERRED RESPONSE: 2

 

DISCUSSION: A number of studies have shown a lower success rate of arthrodesis in smokers.  Animal models also have shown that administration of nicotine can markedly decrease the rate of arthrodesis.  Although it may not be possible to completely eliminate some of the other associated factors that contribute to the failure of arthrodesis, it does appear that nicotine is the primary factor.

 

REFERENCES: Andersen T, Christensen FB, Laursen M, et al: Smoking as a predictor of negative outcome in lumbar spinal fusion.  Spine 2001;26:2623-2628.

Silcox DH III, Daftari T, Boden SD, et al: The effect of nicotine on spinal fusion.  Spine 1995;20:1549-1553.

 

20.    Flexion-distraction injuries of the thoracolumbar spine are most frequently associated with injury to what organ system?

 

1-         Neurologic

2-         Pulmonary

3-         Gastrointestinal

4-         Vascular

5-         Lymphatic

 

PREFERRED RESPONSE: 3

 

DISCUSSION: In patients with flexion-distraction injuries of the thoracolumbar spine, 50% have associated, potentially life-threatening, visceral injuries that occasionally are diagnosed hours or even days after admission.  Based on these findings, consultation with a general surgeon is recommended.  Blunt and penetrating injuries to the cardiopulmonary system or aorta sometimes can be seen with this type of injury, but they are no more common than with other types of thoracolumbar fractures because of the relatively mild bony injury anteriorly.  Neurologic trauma with this type of fracture is also somewhat rare.

 

REFERENCES: Levine AM (ed): Orthopaedic Knowledge Update: Trauma.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1996, pp 351-360.

Inaba K, Kirkpatrick AW, Finkelstein J, et al: Blunt abdominal aortic trauma in association with thoracolumbar spine fractures.  Injury 2001;32:201-207.

 

21.     What is the most common adverse postoperative complication of laminoplasty for multilevel cervical spondylotic myelopathy?

 

1-         Loss of cervical range of motion

2-         Inadvertent closure of the laminoplasty postoperatively

3-         Progressive cervical kyphosis

4-         C5 nerve root palsy

5-         Inadequate decompression of the spinal cord

 

PREFERRED RESPONSE: 1

 

DISCUSSION: A 30% to 50% loss of cervical range of motion is reported postoperatively in most patients following cervical laminoplasty.  Inadvertent closure of the laminoplasty does occur but is rare.  Laminoplasty is advocated in lieu of laminectomy to prevent progressive kyphosis and can effectively decompress the spinal cord.  C5 nerve root palsies are a poorly understood but rare complication of surgical decompression for cervical spondylotic myelopathy.

 

REFERENCES: Emery SE: Cervical spondylotic myelopathy: Diagnosis and treatment.  J Am Acad Orthop Surg 2001;9:376-388. 

Edwards CC II, Riew KD, Anderson PA, et al: Cervical myelopathy: Current diagnostic and treatment strategies.  Spine J 2003;3:68-81.

 

22.    The thickest bone in the occiput is located

 

1-         in no predictable pattern.

2-         at the level of the foramen magnum.

3-         at the level of the external occipital protuberance.

4-         4 cm below the external occipital protuberance.

5-         4 cm lateral to the external occipital protuberance.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Anatomic studies have shown that the thickest bone of the occiput is at the level of the external occipital protuberance.  It ranges from 11.5 mm to 15.1 mm in men and from 9.7 mm to 12 mm in women.  In general, the bone thins as it extends distally from the external occipital protuberance and it also moves laterally from the midline.  The structures at risk during screw placement include the venous sinuses.

 

REFERENCES: Nadim Y, Lu J, Sabry FF, et al: Occipital screws in occipitocervical fusion and their relation to the venous sinuses: An anatomic and radiographic study.  Orthopedics 2000;23:717-719.

Ebraheim N, Lu J, Biyani A, et al: An anatomic study of the thickness of the occipital bone: Implications for occipitocervical instrumentation.  Spine 1996;21:1725-1729.

 

23.     A patient who underwent an L5-S1 diskectomy 18 months ago has persistent pain in the left leg.  Figures 9a and 9b show postoperative axial T₁-weighted MRI scans at the L5-S1 level without and with gadolinium.  What is the most likely diagnosis?

 

1-         Epidural abscess

2-         Neurilemmoma of the left S1 root

3-         L5-S1 diskitis

4-         Recurrent left L5-S1 disk herniation

5-         Left S1 perineural fibrosis

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Persistent or recurrent symptoms after lumbar diskectomy are troublesome and can be difficult to assess.  Gadolinium-enhanced MRI scans may be helpful.  The images show enhancement about the left S1 root, a finding that is most consistent with perineural (epidural) fibrosis.  The root itself does not enhance.  Root enhancement has been associated with compressive radicular symptoms.  A disk herniation does not enhance with gadolinium.  A neurilemmoma enhances with gadolinium, but the involved root would be enlarged.  There is no evidence of a fluid collection which would be consistent with an epidural abscess.

 

REFERENCES: Babar S, Saifuddin A: MRI of the post-discectomy lumbar spine.  Clin Radiol 2002;57:969-981.

Kikkawa I, Sugimoto H, Saita K, et al: The role of Gd-enhanced three-dimensional MRI fast low-angle shot (FLASH) in the evaluation of symptomatic lumbosacral nerve roots.  J Orthop Sci 2001;6:101-109.

Vroomen PC, Van Hapert SJ, Van Acker RE, et al: The clinical significance of gadolinium enhancement of lumbar disc herniations and nerve roots on preoperative MRI.  Neuroradiology 1998;40:800-806.

 

24.    Which of the following factors is most closely associated with early postoperative migration of “stand-alone” lumbar interbody fusion cages?

 

1-         Pseudarthrosis

2-         Placement of the cage through a posterior approach

3-         Placement of the cage laparoscopically through an anterior approach

4-         Use of tapered rather than cylindrical cages

5-         Use of BMP-2 rather than autograft in the cage

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Postoperative migration of lumbar interbody fusion cages is a rare complication.  It is most commonly seen after placement of the cages through a posterior approach, with instability of the final construct.  It is not associated with the design of the cage, the type of graft used, or a resultant pseudarthrosis.

 

REFERENCES: McAfee PC: Interbody fusion cages in reconstructive operations on the spine.  J Bone Joint Surg Am 1999;81:859-880.

McAfee PC, Cunningham BW, Lee GA, et al: Revision strategies for salvaging or improving failed cylindrical cages.  Spine 1999;24:2147-2153.

 

25.    If a laminectomy for spinal stenosis is performed, which of the following is an indication for concomitant arthrodesis at that level?

 

1-         Prior laminectomy at an adjacent level

2-         Ten degrees of degenerative scoliosis

3-         Removal of 25% of each facet joint at surgery

4-         Degenerative spondylolisthesis at the level of the laminectomy

5-         Foraminal stenosis at the level of the laminectomy

 

PREFERRED RESPONSE: 4

 

DISCUSSION: A prospective randomized study of patients with degenerative spondylolisthesis and spinal stenosis by Herkowitz and Kurz showed significantly improved clinical outcomes in patients who also received a lumbar arthrodesis.  Patients with a laminectomy at an adjacent level do not have improved outcomes with an arthrodesis.  Minimal lumbar scoliosis does not require arthrodesis.  Arthrodesis is indicated in cases where there is removal of more than 50% of the facets bilaterally but not with an associated foraminal stenosis.

 

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;73:802-807.

Garfin SR, Rauschning W: Spinal stenosis. Instr Course Lect 2001;50:145-152.

 

26.    Figure 10 shows the MRI scan of a 56-year-old woman with metastatic breast cancer who now reports progressive paraparesis.  Her general health remains good.  Treatment should consist of

 

1-         posterior spinal fusion for stabilization, followed by radiation therapy of the anterior tumor.

2-         radiation therapy and a brace.

3-         chemotherapy, then reevaluation.

4-         anterior corpectomy and stabilization.

5-         laminectomy.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: If the patient’s medical condition and prognosis remain good in the presence of significant and progressive neurologic deficit from cord compression, then the most reliable means of restoring function is via surgical decompression and fusion.  Decompression should be directed toward the compressing structure (eg, anteriorly if the compression is from the anterior side).  This procedure can be done via a posterolateral technique, such as costotransversectomy in some cases.

 

REFERENCE: Fardin DF, Garfin SR, Abitbol J, et al (eds): Orthopaedic Knowledge Update: Spine 2.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 123-133.

 

27.    When 6 weeks of noninvasive nonsurgical management fails to provide relief for a lumbar disk herniation, a trial of epidural steroid injections is likely to yield which of the following results?

 

1-         Eighty percent to ninety percent of patients report rapid and long-lasting relief of symptoms.

2-         Patients with extruded disk herniations report greater relief of symptoms than patients with contained herniations.

3-         Patients with less hydrated disk herniations report the most rapid relief of symptoms.

4-         Patients may experience temporary relief that lasts a maximum of 6 months.

5-         The percentage of patients who report significant improvement is similar to that of patients undergoing diskectomy.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Lumbar epidural steroid injections appear to play a role in management of a lumbar disk herniation that has failed to respond to at least 6 weeks of nonsurgical treatment.  Approximately 42% to 56% of patients report significant pain relief compared with 92% to 98% of those patients treated with diskectomy.  Patients with extruded or sequestered herniations report the greatest and most rapid relief.  Similarly, those with well-hydrated disk fragments report rapid relief of symptoms.  A smaller percentage of patients report symptom relief compared with those having surgery, but the degree of improvement is similar for both groups and the improvement lasts up to 3 years.

 

REFERENCES: Butterman GR: Treatment of lumbar disc herniation: Epidural steroid injection compares with discectomy: A prospective, randomized study.  J Bone Joint Surg Am 2004;86:670-679.

Butterman GR: Lumbar disc herniation regression after successful epidural steroid injection. 
J Spinal Disord Tech 2002;15:469-476. 

 

28.    Which of the following anatomic changes is observed as part of the normal aging process of the adult spine?

 

1-         Overall kyphosis gradually decreases.

2-         Overall lumbar lordosis gradually decreases.

3-         The sagittal vertical line dropped from C7 gradually moves posteriorly relative to the sacrum.

4-         Cervical scoliosis develops.

5-         Coronal balance shifts laterally from the midsacrum.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The primary change that takes place in the aging spine is degeneration of the lumbar disks and loss of the overall lumbar lordosis. This also may be associated with osteopenic-related compression fractures.  With these changes, the sagittal vertical line moves anteriorly relative to the sacrum; cervical scoliosis is uncommon and not part of the normal aging process.  Overall kyphosis in the thoracic spine gradually increases, but the coronal balance remains essentially the same unless scoliosis develops.

 

REFERENCES: Gelb DE, Lenke LG, Bridwell KH, et al: An analysis of sagittal spinal alignment in 100 asymptomatic middle and older aged volunteers.  Spine 1995;20:1351-1358.

Vedantam R, Lenke LG, Keeney JA, et al: Comparison of standing sagittal spinal alignment in asymptomatic adolescents and adults.  Spine 1998;23:211-215.

 

29.    A previously healthy 30-year-old woman has neck pain and bilateral hand and lower extremity tingling with weakness after falling down stairs.  She is alert and oriented.  Examination reveals incomplete quadriplegia at the C6 level that remains unchanged throughout her evaluation and initial treatment.  Radiographs show a bilateral facet dislocation of C6 on C7 without fracture.  Attempts at reduction with halo cervical traction up to her body weight are unsuccessful.  What is the next most appropriate step?

 

1-         Posterior open reduction and fusion with fixation

2-         Anterior open reduction and fusion with fixation

3-         Technetium Tc 99m bone scan

4-         Closed manipulation

5-         MRI

 

PREFERRED RESPONSE: 5

 

DISCUSSION: A facet dislocation that cannot be reduced in an alert, awake patient with some preservation of cord function requires MRI to evaluate the disk prior to a reduction under anesthesia.  The presence or absence of a disk herniation must be assessed, as this factor may influence the method of reduction.

 

REFERENCES: Vaccaro AR, Falatyn SP, Flanders AE, et al: Magnetic resonance evaluation of the intervertebral disc, spinal ligaments, and spinal cord before and after closed traction reduction of cervical spine dislocations.  Spine 1999;24:1210-1217.

Fardon DF, Garfin SR, Abitbol J (eds): Orthopaedic Knowledge Update: Spine 2.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 247-262.

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

Cotler JM, Herbison GJ, Nasuti JF, et al: Closed reduction of traumatic cervical spine dislocation using traction weights up to 140 pounds.  Spine 1993;18:386-390.

 

30.    Which of the following findings is the best radiographic indicator of segmental instability at L4-L5?

 

1-         Anterior marginal osteophytes

2-         Modic end plate changes on MRI

3-         Disk space narrowing

4-         More than 3.5 mm of translation or 11° of angulation compared with adjacent levels on flexion/extension radiographs

5-         More than 4 mm of translation or 10° of angulation compared with adjacent levels on flexion/extension radiographs

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Motion segments that demonstrate more than 4 mm of translation or 10° of angulation compared with adjacent motion segments on flexion-extension radiographs have excessive motion and instability.  Anterior marginal osteophytes form at the insertion of the annulus from increased forces but do not indicate increased motion.  A spondylolisthesis or lateral listhesis is often static without increased motion.  More than 3.5 mm of translation or
11° of angulation is considered instability criteria for the cervical spine.  Internal disk disruption does not denote instability.

 

REFERENCES: Boden SD, Wiesel SW: Lumbosacral segmental motion in normal individuals.  Have we been measuring instability properly?  Spine 1990;15:571-576.

Garfin SR, Rauschning W: Spinal stenosis.  Instr Course Lect 2001;50:145-152.

 

31.     In a patient who has undergone fusion with instrumentation from T4 to the sacrum for adult scoliosis, at which site is a pseudarthrosis most likely to be discovered? 

 

1-         T4-T5

2-         T7-T8

3-         L2-L3

4-         L4-L5

5-         L5-S1

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Although pseudarthrosis can be found anywhere within the spine that has been fused using long multisegmental fixation to the sacrum, it most commonly occurs at the lumbosacral junction.  The thoracolumbar junction is another common site of potential pseudarthrosis.  In this location, the anatomy changes from lumbar transverse processes to thoracic through the transition zone, and overlying instrumentation often makes it difficult to obtain enough sound bone on decorticated bone to achieve a successful fusion.

 

REFERENCES: Saer EH III, Winter RB, Lonstein JE: Long scoliosis fusion to the sacrum in adults with nonparalytic scoliosis: An improved method.  Spine 1990;15;650-653.

Kostuik JP, Hall BB: Spinal fusions to the sacrum in adults with scoliosis.  Spine
1983;8:489-500.

Balderston RA, Winter RB, Moe JH, et al: Fusion to the sacrum for nonparalytic scoliosis in the adult.  Spine 1986;11:824-829.

 

32.     The afferent pain innervation of the L3-L4 facet joint arises from the medial branch
nerve of

 

1-         L2.

2-         L3.

3-         L4.

4-         L2 and L3.

5-         L3 and L4.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Afferent pain fibers to the lumbar facet joints arise from the medial branch nerves originating from the next two cephalad levels.  Therefore, innervation of the L3-L4 facet joint arises from the L2 and L3 medial branch nerves.  This effect should be taken into account when considering a medial branch block or facet denervation.  The medial branch nerve arises from the dorsal ramus of the exiting nerve root.

 

REFERENCES: Nade SL, Bell E, Wyke BD: The innervation of the lumbar spinal joint and its significance.  J Bone Joint Surg Br 1980;62:255-261

Kornick C, Kramarich SS, Lamer TJ, et al: Complications of lumbar facet radiofrequency denervation.  Spine 2004;29:1352-1354.

 

33.     When posterior fusion with instrumentation to the sacrum is used to treat adult
scoliosis, what instrumentation technique best increases the chance of a successful lumbosacral fusion?

 

1-         Addition of sublaminar wires to the midlumbar spine

2-         Cross-linking of the longitudinal rods

3-         Use of multiple claw hook fixation in the upper thoracic spine

4-         Use of large-diameter rods and pedicle screws

5-         Fixation into both the ilium and the sacrum

 

PREFERRED RESPONSE: 5

 

DISCUSSION: As the chance of success of lumbosacral fusion increases with the stiffness and rigidity of the construct, fixation and stiffness improve with fixation into both the upper sacrum and the ilium.  In a review of individuals treated with long constructs to the pelvis for adult scoliosis, Islam and associates reported that the rate of pseudarthrosis was significantly lower with sacral and iliac fixation compared with sacral fixation alone or iliac fixation alone.  Iliac screws provide significant fixation anterior to the instantaneous axis of rotation for flexion and extension, as well as provides resistance to lateral bending and rotational forces.  Numerous biomechanical studies support the concept of increasing biomechanical stabilization with increased fixation from the sacrum to the ilium.

 

REFERENCES: Islam NC, Wood KB, Transfeldt EE, et al: Extension of fusions to the pelvis in idiopathic scoliosis.  Spine 2001;26:166-173.

O’Brien N, et al: Sacral pelvic fixation and spinal deformity, in DeWald RL (ed): Spinal Deformities: A Comprehensive Text.  New York, NY, Thieme, 2003, pp 601-614.

McCord DH, Cunningham BW, Shono Y, et al: Biomechanical analysis of lumbosacral fixation.  Spine 1992;17:S235-S243.

 

34.     Which of the following structures runs through the site indicated by the arrow in
Figure 11?

 

1-         Vertebral artery

2-         Posterior occipital artery

3-         Hypoglossal nerve

4-         Greater occipital nerve

5-         Tectorial membrane

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The vertebral artery traverses through the arcuate foramen after exiting the lateral aspect of C1 and before entering the skull.  The foramen usually is not fully formed, but a complete foramen such as this one has been reported in up to 18% of patients.

 

REFERENCES: Stubbs DM: The arcuate foramen: Variability in distribution related to race and sex.  Spine 1992;17:1502-1504.

Hasan M, Shukla S, Siddiqui MS, et al: Posterolateral tunnels and ponticuli in human atlas vertebrae.  J Anat 2001;199:339-343.

 

35.     A 42-year-old man has had left lower extremity pain in an L5 radicular pattern for the past 6 weeks.  He denies significant axial low back pain.  History reveals that he underwent an L4-5 diskectomy with successful relief of similar pain 5 years ago.  Which of the following imaging studies would offer the greatest amount of information?

 

1-         Lumbar MRI with gadolinium

2-         CT

3-         CT with contrast myelography

4-         Lumbar lateral flexion-extension radiographs

5-         Bone scan with CT correlation

 

PREFERRED RESPONSE: 1

 

DISCUSSION: MRI with gadolinium will best identify recurrent herniated nucleus pulposus or other root compression and distinguish scar from recurrent disk.  CT is unable to distinguish scar from recurrent disk density, and the addition of myelogram dye can reveal compromise of the thecal sac but cannot distinguish the scar from recurrent disk as the source of compression.  Although lateral flexion-extension radiographs may be important to rule out any instability, much of that information can be inferred from the associated disk and adjacent bony changes on MRI.  Bone scan techniques may identify subtle stress fractures resulting from previous aggressive facet resection, but low back pain also would be expected.

 

REFERENCES: Mirowitz SA, Shady KL: Gadopentetate dimeglumine-enhanced MR imaging of the postoperative lumbar spine: Comparison of fat-suppressed and conventional T₁-weighted images.  Am J Roentgenol 1992;159:385-389.

Fardin DF, Garfin SR, Abitbol J, et al (eds): Orthopaedic Knowledge Update: Spine 2.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 63-79.

 

36.     Figure 12 shows the radiograph of an 80-year-old woman who has had an 8-month history of back pain after a fall.  What is the most likely diagnosis based on the radiographic findings at the fractured vertebrae?

 

1-         A healing osteoporotic compression fracture

2-         A pathologic fracture that is the result of an underlying neoplasm

3-         Nonunion of the fracture with osteonecrosis

4-         Vertebral osteomyelitis

5-         Degeneration of the adjacent intervertebral disk

 

PREFERRED RESPONSE: 3

 

DISCUSSION: An intravertebral vacuum cleft suggests nonunion of the vertebral fracture with osteonecrosis and is not seen in routine healing fractures.  MRI characteristically shows a high T2 signal in the cleft.  The cleft is not indicative of an infectious or neoplastic lesion.  A vacuum disk phenomenon is associated with end-stage degenerative disk disease, but those findings are not found in the vertebral body.

 

REFERENCES: Murakami H, Kawahara N, Gabata T, et al: Vertebral body osteonecrosis without vertebral collapse.  Spine 2003;28:E323-E328.

Jang JS, Kim DY, Lee SH: Efficacy of percutaneous vertebroplasty in the treatment of intravertebral pseudarthrosis associated with noninfected avascular necrosis of the vertebral body.  Spine 2003;28:1588-1592.

 

37.    Which of the following complications is uniquely associated with an anterior approach to the lumbosacral junction? 

 

1-         Nerve root injury

2-         Erectile dysfunction

3-         Dural tear

4-         Pulmonary embolism

5-         Retrograde ejaculation

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Retrograde ejaculation is a sequela of injury to the superior hypogastric plexus.  The structure needs protection, especially during anterior exposure of the lumbosacral junction.  The use of monopolar electrocautery should be avoided in this region.  The ideal exposure starts with blunt dissection just to the medial aspect of the left common iliac vein, sweeping the prevertebral tissues toward the patient’s right side.  Although erectile dysfunction can be seen after spinal surgery, it is not typically related to the surgical exposure because erectile function is regulated by parasympathetic fibers derived from the second, third, and fourth sacral segments that are deep in the pelvis and are not at risk with the anterior approach.  The other choices are complications of spinal surgery but are not uniquely associated with an anterior L5-S1 exposure.

 

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

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

An HS, Riley LH III: An Atlas of Surgery of the Spine.  New York, NY, Lippincott Raven, 1998, p 263.

 

38.    A 68-year-old woman with a history of rheumatoid arthritis has had neck pain and weakness in all four extremities that has become worse in the past 6 months.  She has gone from a community to a household ambulator and uses a wheelchair outside of the home.  Examination of the extremities reveals poor coordination, diffuse weakness, hyperactive reflexes, and bilateral sustained clonus.  She has a broad-based and unsteady gait.  The posterior atlanto-dens interval is 12 mm.  Based on these findings and the radiograph and MRI scan shown in Figures 13a and 13b, the treatment of choice is surgical decompression and stabilization.  However, the patient inquires about the prognosis with surgery compared to nonsurgical management.  Assuming there are no complications from surgery, the patient should be informed that, with surgery, she will most likely

 

1-         live longer and have stable neurologic function.

2-         live longer and have improved neurologic function.

3-         not live longer and deteriorate neurologically.

4-         not live longer but will have improved neurologic function.

5-         not live longer but will have stable neurologic function.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The patient has a cervical myelopathy with more than 10 mm of space available for the cord; therefore, she has a reasonable chance of improved neurologic function following surgery.  If not treated with surgery, however, her neurologic condition likely will worsen and she will die earlier than if she had surgery.

 

REFERENCES: Matsunaga S, Sakou T, Onishi T, et al: Prognosis of patients with upper cervical lesions caused by rheumatoid arthritis: Comparison of occipitocervical fusion between C1 laminectomy and nonsurgical management.  Spine 2003;28:1581-1587.

Boden SD, Dodge LD, Bohlman HH, et al: 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.

 

39.    Five weeks after undergoing a successful L4-L5 diskectomy, with complete relief of his preoperative sciatica, a 36-year-old man has severe, relentless back and buttock pain.  Examination and laboratory studies are unremarkable with the exception of an erythrocyte sedimentation rate (ESR) of 90 mm/h.  What is the next most appropriate step in management?

 

1-         Broad-spectrum intravenous antibiotics

2-         AP, lateral, and flexion-extension lateral radiographs

3-         MRI with gadolinium

4-         Open biopsy of the surgical disk space

5-         Anterior debridement and interbody fusion

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The patient’s history, including the timing and type of symptoms, is typical for postoperative diskitis.  The elevated ESR, 5 weeks after surgery, is also consistent with infection; a normal WBC count is not unusual.  Management should consist of MRI with gadolinium; if positive, this should be followed by percutaneous biopsy to confirm the organism.  Open biopsy may be considered if the percutaneous biopsy is unsuccessful.  Anterior debridement and interbody fusion is reserved for the occasional patient that fails to respond to intravenous antibiotics, bed rest, and immobilization.

 

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

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

 

40.    An 18-year-old man sustained a knife injury to his midback, with the entry wound 2 cm to the left of the midline.  He has been diagnosed with a hemicord transection.  Neurologic examination will most likely reveal left-sided loss of

 

1-         vibratory and light touch sensation and motor function, and right-sided loss of pain and temperature sensation.

2-         pain and temperature sensation and motor function, and right-sided loss of vibratory and light touch sensation.

3-         pain, temperature, vibratory, and light touch sensation and motor function.

4-         motor function, and right-sided loss of pain, temperature, vibratory, and light touch sensation.

5-         light touch and pain sensation and motor function, and right-sided loss of vibratory and temperature sensation.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Brown-Sequard syndrome results from an injury to one half of the spinal cord and is characteristically seen in penetrating injuries.  The spinothalamic fibers cross the midline below the level of the lesion, resulting in contralateral loss of pain and temperature sensation.  The posterior columns and corticospinal tracts carry vibratory, position, and light touch sensation, as well as motor function from the ipsilateral side of the body.  This results in the characteristic neurologic findings seen with Brown-Sequard syndrome.

 

REFERENCES: 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 541-549.

Collins RD: Illustrated Manual of Neurologic Diagnosis.  Philadelphia, PA, JB Lippincott, 1962, p 71.

 

41.     When using surgery extending to the pelvis to treat long spinal deformity in adults, the addition of anterior interbody structural support at the lumbosacral junction serves what biomechanical function?

 

1-         Improves the bone mineral density of the vertebral bodies

2-         Reduces the strain at the adjacent intervertebral disk

3-         Reduces the stiffness of the posterior instrumentation

4-         Reduces the strain on posterior instrumentation

5-         Increases the strength of the posterior instrumentation

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Shufflebarger and others have reported that the placement of anterior interbody structural support at the lumbosacral junction increases the overall construct stiffness and reduces the strain on posterior instrumentation, thereby reducing the risk of screw pull-out or fracture.  The stiffness of the posterior instrumentation actually increases, whereas the actual strength of the instrumentation remains the same.  Actual strain measured at an adjacent intervertebral disk to a fusion construct is expected to increase.

 

REFERENCES: Shufflebarger HL: Moss-Miami spinal instrumentation system: Methods of fixation of the spondylopelvic junction, in Margulies JI, Floman Y, Farcy JPC, et al (eds): Lumbosacral and Spinal Pelvic Fixation.  Philadelphia, PA, Lippincott-Raven, 1996, pp 381-393.

Cunningham BW: A biomechanical approach to posterior spinal instrumentation: principles and applications, in DeWald RL (ed): Spinal Deformities: A Comprehensive Text.  New York, NY, Thieme, 2003, pp 588-600.

Kostuik JP, Valdevit A, Chang HG, et al: Biomechanical testing of the lumbosacral spine.  Spine 1998;23:1721-1728.

 

42.    A 40-year-old woman has had sciatic pain on the left side for the past 8 weeks.  She reports that the pain radiates to her posterior thigh, lateral calf, and into the dorsum of her left foot.  Neurologic examination shows weakness of the left extensor hallucis longus.  Axial T₂-weighted MRI scans through L4-L5 are shown in Figure 14.  Management should consist of

 

1-         CT-guided needle biopsy at L4-L5.

2-         a bone survey.

3-         anterior interbody fusion.

4-         left L4-L5 microdiskectomy.

5-         left L4-L5 hemilaminectomy and partial facetectomy.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The MRI scans show hypertrophy of the left L4-L5 facet joint and ligamentum flavum, with a synovial cyst.  Appropriate surgical management consists of a hemilaminectomy and direct decompression of the neural elements.  Fusion, in addition to the decompression, may be considered, particularly in patients with an associated spondylolisthesis.

 

REFERENCES: Epstein NE: Lumbar laminectomy for the resection of synovial cysts and coexisting lumbar spinal stenosis or degenerative spondylolisthesis: An outcome study.  Spine 2004;29:1049-1055.

Shah RV, Lutz GE: Lumbar intraspinal synovial cysts: Conservative management and review of the world’s literature.  Spine J 2003;3:479-488. 

 

43.     During C1-C2 transarticular screw fixation, screw misplacement is most likely to result in injury to the

 

1-         spinal cord if the screw is angled too medial.

2-         occiput-C1 joint if the screw is angled too cephalad.

3-         occiput-C1 joint if the screw is angled too lateral.

4-         vertebral artery if the screw is angled too cephalad.

5-         vertebral artery if the screw is angled too caudally.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: With C1-C2 transarticular screw fixation, the following structures are potentially at risk: vertebral artery, spinal cord, occiput-C1 joint, and hypoglossal nerve.  The vertebral artery is most vulnerable to injury with drill misdirection or anatomic variations in the vertebral foramen.  The hypoglossal nerve may be injured if the drill, tap, or screw passes too far anterior to the lateral mass of C1.  This complication is extremely rare.  The occiput-C1 joint may be injured if the screw trajectory is too cephalad or cranially directed; however,this scenario is very unlikely because the exposure tends to direct the screw into a caudally inclined direction.  This caudal orientation has the potential to cause vertebral artery injury, especially in patients who have a large vertebral foramen in the lateral mass of C2 because of erosions (rheumatoid arthritis) or anatomic variation.  CT of the vertebral foramen is recommended when C1-C2 transarticular fixation is being considered.  Spinal cord injury is extremely unlikely because of the very large size of the spinal canal in the upper cervical spine; the spinal cord lies far away from the lateral masses of C1 and C2.

 

REFERENCES: Mueller ME, Allgower M, et al: Manual of Internal Fixation, ed 3.  New York, NY, Springer-Verlag, 1991, pp 634-636.

Gebhard JS, Schimmer RC, Jeanneret B: Safety and accuracy of transarticular screw fixation C1-C2 using an aiming device: An anatomic study.  Spine 1998;23:2185-2189.

 

44.    A 27-year-old professional soccer player sustained an injury to his cervical spine
in a collision with another player.  Initially he was diagnosed with a right C6 radiculopathy that resolved with rest, anti-inflammatory medications, and physical therapy.  Following a fall in a game, he noted a recurrence of neck pain without radicular signs or symptoms.  Additional nonsurgical management over the past few months has failed to provide relief.  A cervical MRI scan shows a right-sided C5-6 herniation without any evidence of disk disease at other cervical levels.  The patient desires to continue his career as a professional soccer player.  What treatment offers the best long-term option for return to play?

 

1-         Right-sided posterior keyhole foraminotomy at C5-6 

2-         Transforaminal epidural steroid injection at C5-6 

3-         Single-level C5-6 anterior cervical fusion

4-         Posterior C5-6 fusion

5-         Continued nonsurgical management and counseling that his career as a professional athlete is over

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The patient has chronic neck pain that is affecting his career as a professional soccer player.  Although he had signs and symptoms of a right C6 radiculopathy, neck pain is his only current symptom.  Therefore, procedures to address the relief of radiculopathy (keyhole foraminotomy and transforaminal epidural steroid injection) are likely to be ineffective.  Although Watkins and others have described continuing nonsurgical management for symptomatic herniated disks and return to play only when asymptomatic, the patient has not found relief with these modalities.  A single-level cervical fusion (either postoperative or congenital) generally is not considered a contraindication for return to play in collision or
contact sports.  Therefore, anterior cervical fusion at C5-6 offers the best long-term option for return to play.

 

REFERENCES: Watkins RG: Cervical spine injuries in athletes, in Clark CR (ed): The Cervical Spine, ed 3.  Philadelphia, PA, Lippincott Raven, 1998, pp 373-386.

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

Morganti C, Sweeney CA, Albanese SA, et al: Return to play after cervical spine injury.  Spine 2001;26:1131-1136.

Garvey T, Transfeldt EE, Malcolm JR, et al: Outcome of anterior cervical discectomy and fusion as perceived by patients treated for dominant axial-mechanical cervical spine pain.  Spine 2002;27:1887-1895.

 

45.    A collegiate football player who sustained an injury to his neck has significant neck pain and weakness in his extremities.  Following immobilization, which of the following steps should be taken prior to transport?

 

1-         His helmet should be removed.

2-         His helmet and shoulder pads should be removed.

3-         His face mask should be removed.

4-         All equipment should be removed.

5-         No equipment should be removed.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Prior to transport, the face mask should be removed so that the airway can be easily accessible.  If serious injury is suspected, the helmet and shoulder pads should be left in place until he is assessed at the hospital and radiographs are obtained.  Leaving the helmet and shoulder pads in place helps to keep the spine in the most neutral alignment.  Removal of the helmet will result in extension of the neck, whereas removal of the shoulder pads will most likely result in flexion of the neck.

 

REFERENCES: Clark CR (ed): The Cervical Spine, ed 3.  Philadelphia, PA, Lippincott Williams & Wilkins, 1998, p 376.

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

Waninger KN, Richards JG, Pan WT, et al: An evaluation of head movement in backboard-immobilized helmeted football, lacrosse, and ice hockey players.  Clin J Sport Med
2001;11:82-86.

Donaldson WF III, Lauerman WC, Heil B, et al: Helmet and shoulder pad removal from a player with suspected cervical spine injury: A cadaveric model.  Spine 1998;23:1729-1732.

Peris MD, Donaldson WF III, Towers J, et al: Helmet and shoulder pad removal in suspected cervical spine injury: Human control model.  Spine 2002;27:995-998.

 

46.    What is the most common complication following total disk arthroplasty in the
lumbar spine?

 

1-         Implant migration

2-         Deep venous thrombosis

3-         Transient retrograde ejaculation

4-         Transient radicular leg pain

5-         Incisional hernia

 

PREFERRED RESPONSE: 4

 

DISCUSSION: In a midterm (7 to 11 years) follow-up study of lumbar total disk arthroplasty, 5 of 55 patients had transient radicular leg pain without evidence of nerve root compression.  Implant migration is rare.  Deep venous thrombosis, incisional hernia, and retrograde ejaculation are less common complications of disk arthroplasty.

 

REFERENCE: Tropiano P, Huang RC, Girardi FP, et al: Lumbar total disc replacement: Seven to eleven-year follow-up.  J Bone Joint Surg Am 2005;87:490-496.

 

47.    A 42-year-old woman has cervical stenosis and radicular deficits at the C5-6 and C6-7 levels.  History reveals that she has smoked one pack of cigarettes a day for 25 years.  Because nonsurgical management has failed to provide relief, she is now seeking surgical treatment.  After preoperative counseling, it becomes clear that she is not likely to stop smoking.  Which of the following surgical procedures should be used?

 

1-         Anterior diskectomy and interbody fusion with autograft at C5-6 and C6-7

2-         Anterior diskectomy at C5-6 and C6-7, subtotal corpectomy at C6, and iliac strut autograft at C5 to C7

3-         Anterior diskectomy at C5-6 and C6-7 without fusion

4-         Anterior diskectomy at C5-6 and C6-7, subtotal corpectomy at C6, and allograft strut at C5 to C7

5-         Multilevel diskectomy and allograft interbody fusion

 

PREFERRED RESPONSE: 2

 

DISCUSSION: In a review of 190 anterior cervical fusions, Hilibrand and associates reported that only 20 of 40 patients who smoked had solid fusion at all levels, whereas 64 of 91 nonsmokers had solid fusions at all levels when treated with multilevel interbody technique (Smith-Robinson).  When fused with strut grafts, 14 of 15 smokers and 41 of 44 nonsmokers had solid fusions with a fusion rate of 93% in the same series.  Multilevel allografts have a lower fusion rate than autografts, and diskectomy without fusion has an increased rate of residual
neck pain.

 

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

Zdeblick TA, Ducker TB: The use of freeze-dried allograft bone for anterior cervical fusions.  Spine 1991;16:726-729.

 

48.    An otherwise healthy 54-year-old man who underwent a successful multilevel lumbar decompression and fusion 4 years ago now reports increasingly severe bilateral thigh claudication with paresthesia and severe back pain for the past 12 months.  Physical therapy, bracing, and epidural steroids have failed to provide relief.  A radiograph and MRI scans are shown in Figures 15a through 15c.  He is afebrile, and laboratory studies show an erythrocyte sedimentation rate of 5 mm/h and a normal WBC count.  What is the best course of action?

 

1-         Referral to the pain clinic to consider insertion of a morphine pump

2-         L1-2 laminectomy

3-         L1-2 anterior lumbar interbody fusion via a minimally invasive technique

4-         Posterior laminectomy and uninstrumented fusion

5-         Posterior decompression and instrumented fusion

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The patient has degeneration of an adjacent segment with resultant
kyphosis and stenosis.  Because he is healthy, has responded well to previous surgery,
|and has a potentially correctable lesion, he is not a good candidate for an end-stage failed
back procedure such as a morphine pump.  The stenosis is exacerbated by the deformity; therefore, a simple decompression will contribute to instability.  Because of the kyphosis and the patient’s relatively young age, the treatment of choice is restoration of sagittal alignment and posterior decompression.

 

REFERENCE: Eck JC, Humphreys SC, Hodges SD: Adjacent-segment degeneration after lumbar fusion: A review of clinical, biomechanical, and radiographic studies.  Am J Orthop 1999;28:336-340.

 

49.    Which of the following is considered a risk factor for the development of low back pain?

 

1-         Gender

2-         Facet trophism

3-         Vibration exposure

4-         Weight

5-         Transitional vertebrae

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Risk factors associated with low back pain include poor physical fitness, smoking, a history of repetitive bending or stooping on the job, or whole body vibration exposure.  Some radiographic factors such as stenosis, spondyloarthropathy, severe deformity, or instability are also associated with low back pain.  Gender, weight, transitional anatomy, or facet trophism are not associated with low back pain.

 

REFERENCE: Koval KJ (ed): Orthopaedic Knowledge Update 7.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 627-643.

 

50.    A corset-type brace may help reduce symptoms during an episode of acute low back pain as the result of

 

1-         decreased intervertebral motion in the sagittal plane.

2-         decreased intervertebral motion in the coronal plane.

3-         decreased intervertebral motion in the axial plane.

4-         decreased intradiskal pressure.

5-         increased intradiskal temperature.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Although there is no significant alteration in motion with a corset, studies have shown a decrease in intradiskal pressure.

 

REFERENCES: Nachemson A, Morris JM: In vivo measurements of intradiscal pressure: Discometry, a method for determination of pressure in the low lumbar disc.  J Bone Joint Surg Am 1964;46:1077-1092.

Axelsson P, Johnsson R, Stromqvist B: Effect of lumbar orthosis on intervertebral mobility: A roentgen stereophotogrammetric analysis.  Spine 1992;17:678-681.

 

51.     Figure 16 shows the radiograph of a 56-year-old man who has neck pain after a rollover accident on his lawnmower.  The injury appears to be isolated, and he is neurologically intact.  Management of the fracture should consist of

 

1-         posterior C1-2 fusion.

2-         anterior C2-3 fusion.

3-         Gardner-Wells traction for 6 weeks, followed by 6 weeks of halo vest immobilization.

4-         halo vest immobilization.

5-         a hard collar.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The radiograph shows a type IIa Hangman’s fracture, and the classic treatment is halo vest immobilization.  Traction should be avoided in type IIa injuries because of the risk of overdistraction.  A lesser form of immobilization such as a hard collar or a Minerva jacket can be used for nondisplaced (type I) fractures.  Surgery generally is reserved for type III fractures (includes C2-3 facet dislocation), or extenuating circumstances such as multiple trauma or other fractures of the cervical spine that require surgical stabilization.

 

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

Jackson RS, Banit DM, Rhyne AL III, et al: Upper cervical spine injuries.  J Am Acad Orthop Surg 2002;10:271-280.

 

52.    Degenerative spondylolisthesis of the cervical spine is most commonly seen at which of the following levels?

 

1-         C1-2

2-         C3-4

3-         C5-6

4-         C6-7

5-         C7-T1

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Degenerative spondylolisthesis of the cervical spine is seen almost exclusively at C3-4 and C4-5; this is in contrast to degenerative changes, which are most commonly seen at C5-6 and C6-7.

 

REFERENCES: Tani T, Kawasaki M, Taniguchi S, et al: Functional importance of degenerative spondylolisthesis in cervical spondylotic myelopathy in the elderly.  Spine 2003;28:1128-1134.

Fardon DF, Garfin SR, Abitbol J, et al (eds): Orthopedic Knowledge Update: Spine 2.  Rosemont, IL, American Academy of Orthopedic Surgeons, 2002, pp 299-309.

 

53.     Thoracic disk herniations are most frequently found in what area of the spine?

 

1-         C7-T2

2-         T2-T5

3-         T5-T8

4-         T9-T12

5-         T12-L1

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Although thoracic disk herniations have been reported at all levels of the thoracic spine, more than two thirds are found at T9-T12, which is the more mobile lower third of the thoracic region.

 

REFERENCES: Belanger TA, Emery SE: Thoracic disc disease and myelopathy, in Frymoyer JW, Wiesel SW (eds): The Adult and Pediatric Spine.  Philadelphia, PA, Lippincott Williams and Wilkins, 2004, pp 855-864.

Bohlman HH, Zdeblick TA: Anterior excision of herniated thoracic discs.  J Bone Joint Surg Am 1988;70:70-77.

 

54.    In a patient who has had low back pain for less than 2 weeks, which of the following findings is an indication for continued observation and symptomatic treatment rather than more aggressive evaluation and/or treatment?

 

1-         Inability to control urinary function

2-         Inability to participate in athletics

3-         Decreased sphincter tone and function

4-         History of previous malignancy

5-         History of a fall preceding the pain

 

PREFERRED RESPONSE: 2

 

DISCUSSION: An inability to participate in athletics generally is considered an indication for continued symptomatic treatment only.  All of the other answers suggest the possibility of more significant pathology that may require more urgent treatment.

 

REFERENCES: Frymoyer JW: Back pain and sciatica.  N Engl J Med 1988;318:291-300.

McCullough JA, Transfeldt EE: Macnab’s Backache, ed 3.  Baltimore, MD, Williams and Wilkins, 1997, pp 240-357.

 

55.    Radiographs of an 80-year-old woman with back pain reveal a compression fracture.  Which of the following imaging studies best evaluates the acuity of the fracture?

 

1-         Triple phase bone scan

2-      T₁-weighted MRI scan

3-         Short tau inversion recovery (STIR)-weighted MRI scan

4-         CT

5-         Standing lateral radiograph

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The best method of evaluating the acuity of osteoporotic compression fractures is to look for edema in the vertebral body.  This is best accomplished with a STIR-weighted MRI scan.  Bone scans can show increased uptake at the site of fracture for many months after the fracture.  T₁-weighted MRI scans show loss of normal marrow fat that may not necessarily correspond with acuity of the fracture.  CT scans and radiographs show fracture deformity but cannot be used to judge acuity.

 

REFERENCES: Phillips FM: Minimally invasive treatments of osteoporotic vertebral compression fractures.  Spine 2003;28:S45-S53.   

Rao RD, Singrakhia MD: Painful osteoporotic vertebral fracture: Pathogenesis, evaluation, and roles of vertebroplasty and kyphoplasty in its management.  J Bone Joint Surg Am 2003;85:2010-2022.

 

56.    A 24-year-old professional football player underwent surgery for a symptomatic cervical disk herniation with radiculopathy 9 months ago.  A current radiograph is shown in Figure 17.  He has normal neurologic findings, no pain, and full range of motion. 
A CT scan shows a solid fusion.  When can he expect to return to play?

 

1-         Immediately

2-         In three games

3-         After anterior plate removal

4-         Next season

5-         Cannot return

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The radiograph shows that the two-level anterior cervical diskectomy and fusion has healed.  In addition, the patient has good range of motion and the neurologic examination is normal.  Based on these findings, the patient can return to play immediately.  Patients with one- or two-level anterior cervical diskectomies and fusions that have healed fully can return to play. Any loss of motion, persistent neurologic deficit, or significant adjacent segment degeneration may preclude a player from returning.

 

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

Torg JS, Ramsey-Emrhein JA: Management guidelines for participation in collision activities with congenital, developmental, or post-injury lesions involving the cervical spine.  Clin Sports Med 1997;16:501-530.

 

57.    When treating thoracic disk herniations, which of the following surgical approaches has the highest reported rate of neurologic complications?

 

1-         Video-assisted thoracoscopic approach (VATS)

2-         Posterior

3-         Posterior-lateral

4-         Transthoracic

5-         Transpedicular

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Numerous surgical approaches have been used for thoracic diskectomy, including the most recent VATS.  One of the first approaches described, posterior laminectomy, involves manipulation of the spinal cord, which the other approaches avoid.  The posterior approach had dismal results, including further neurologic deterioration and even paralysis. 

 

REFERENCES: Belanger TA, Emery SE: Thoracic disc disease and myelopathy, in Frymoyer JW, Wiesel SW (eds): The Adult and Pediatric Spine.  Philadelphia, PA, Lippincott Williams and Wilkins, 2004, pp 855-864.

Benjamin V: Diagnosis and management of thoracic disc disease.  Clin Neurosurg
1983;30:577-605.

Russell T: Thoracic intervertebral disc protrusion: Experience of 67 cases and review of the literature.  Br J Neurosurg 1989;3:153-160.

Fessler RG, Sturgill M: Review: Complications of surgery for thoracic disc disease.  Surg Neurol 1998;49:609-618.

 

58.    When harvesting iliac crest bone graft during a posterior spinal decompression and fusion, injury to what structure can result in painful neuromas or numbness over the skin of the buttocks?

 

1-         Ilioinguinal nerve

2-         Superior gluteal nerve

3-         Superior cluneal nerves

4-         Iliohypogastric nerves

5-         Lateral femoral cutaneous nerve

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The superior cluneal nerves (L1, L2, and L3) are most at risk when harvesting iliac crest bone graft during a posterior decompression and fusion.  These nerves pierce the lumbodorsal fascia and cross the posterior iliac crest, beginning 8 cm lateral to the posterior superior iliac spine.  The ilioinguinal nerve is more at risk during exposure of the anterior ilium during retraction of the iliacus and abdominal wall muscles.  Iliohypogastric nerve injury may arise in a similar fashion to ilioinguinal neuralgia.  The lateral femoral cutaneous nerve lies in close proximity to the anterior superior iliac spine and is also at risk with anterior iliac crest bone graft harvesting.  The superior gluteal nerve courses through the sciatic notch and supplies motor branches to the gluteus medius, minimus, and tensor fascia lata muscles.  Injury results in hip abduction weakness.

 

REFERENCES: An HS: Principles and Techniques of Spine Surgery.  Baltimore, MD, Williams and Wilkins 1998, pp 770-773.

Kurz LT, Garfin SR, Booth RE Jr: Harvesting autogenous iliac bone grafts: A review of complications and techniques.  Spine 1989;14:1324-1331.

Mrazik J, Amato C, Leban S, et al: The ilium as a source of autogenous bone grafting: Clinical considerations.  J Oral Surg 1980;38:29-32.

 

59.    A 42 year-old-woman who underwent surgery for lumbar scoliosis 2 years ago now has fixed sagittal plane imbalance and severe back pain.  Which of the following is considered a contraindication to isolated pedicle subtraction osteotomy for the treatment of iatrogenic flatback syndrome in this patient?

 

1-         Anterior pseudarthrosis

2-         Prior laminectomy at the osteotomy level

3-         Sagittal decompensation of more than 20 cm on standing lateral radiographs

4-         Kyphosis at the thoracolumbar junction

5-         Vascular calcification at the osteotomy site

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Pedicle subtraction osteotomy is the preferred osteotomy technique for the treatment of many patients with iatrogenic flatback syndrome.  In the presence of an anterior pseudarthrosis, however, it must be done in conjunction with an anterior procedure.  Prior laminectomy is not a contraindication.  Significant correction, usually averaging about 30°, can be obtained through each osteotomy.  Osteotomies should be performed at L2 or below in the presence of kyphosis at the thoracolumbar junction.  The pedicle subtraction technique is preferred with vascular calcifications because it does not lengthen the anterior column, which could risk vascular injury.

 

REFERENCES: Potter BK, Lenke LG, Kuklo TR: Prevention and management of iatrogenic flatback deformity.  J Bone Joint Surg Am 2004;86:1793-1808.

Bridwell KH, Lenke LG, Lewis SJ: Treatment of spinal stenosis and fixed sagittal imbalance.  Clin Orthop 2001;384:35-44.

 

60.    A 42-year-old man sustained a burst fracture at L2 in a motor vehicle accident.  Examination reveals that he is neurologically intact.  Figure 18 shows a cross-sectional CT scan through the fracture.  If the fracture is managed nonsurgically for the next 2 years, the retained fragments can be expected to

 

1-         remain essentially unchanged in size.

2-         result in neurologic deterioration.

3-         gradually resorb and widen the spinal canal.

4-         potentially migrate within the spinal canal.

5-         increase the risk of further injury to the adjacent dural sac.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Numerous articles have reported that both surgical and nonsurgical management of burst fractures are associated with resolution of impingement at long-term follow-up.  If the patient is neurologically intact and appropriately treated at the time of injury, neurologic deterioration is not expected nor is there a risk of injury to the dural sac.  The retained fragments can be expected to gradually resorb and widen the spinal canal.

 

REFERENCES: Mumford J, Weinstein JN, Spratt KF, et al: Thoracolumbar burst fractures: The clinical efficacy and outcome of nonoperative management.  Spine 1993;18:955-970.

Wood KB, Butterman G, Mehbod A, et al: Operative compared with nonoperative treatment of a thoracolumbar burst fracture without neurologic deficit: A prospective, randomized study.  J Bone Joint Surg Am 2003;85:773-781.

 

61.     A 50-year-old man reports the onset of back pain and incapacitating pain radiating down his left leg posterolaterally and into the first dorsal web space of his foot 1 day after doing some yard work.  He denies any history of trauma.  Examination reveals ipsilateral extensor hallucis longus weakness.  MRI scans are shown in Figures 19a through 19c.  What nerve root is affected?

 

1-         Left L4

2-         Right L4

3-         Left L5

4-         Right L5

5-         Left S1

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The MRI scans clearly show an extruded L4-5 disk that is affecting the L5 root on the left side.  In addition, the L5 root has a cutaneous distribution in the first dorsal web space.  S1 affects the lateral foot, and L4 affects the medial calf.

 

REFERENCES: An HS: Principles and Techniques of Spine Surgery.  Baltimore, MD, Williams and Wilkins, 1998, pp 98-100.

Hoppenfeld S: Orthopaedic Neurology.  Philadelphia, PA, JB Lippincott, 1977, pp 7-49.

 

62.    Which of the following pharmacologic agents is most likely to adversely affect the success rate of bony union after lumbar arthrodesis?

 

1-         Oxycodone hydrochloride

2-         Hydrocodone/acetaminophen

3-         Tramadol

4-         Imipramine

5-         Ketorolac

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Glassman and associates reported a significantly higher pseudarthrosis rate when ketorolac was used postoperatively compared to a similar group of patients who were not given ketorolac.  Animal studies from the same institution support these clinical findings.  To reduce narcotic dosage, nonsteroidal anti-inflammatory drugs (NSAIDs) have been promoted as an adjunct for postoperative analgesia in patients undergoing spinal fusion.  However, a high failure rate of arthrodesis has been associated with postoperative use of NSAIDs.  The analgesics oxycodone hydrochloride, hydrocodone/acetaminophen, and tramadol, as well as the tricyclic antidepressant imipramine, have not been shown to inhibit fusion.

 

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

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

 

63.     A 69-year-old woman is seen in the emergency department with a bilateral C5-6 facet dislocation and complete quadriplegia after falling down a flight of stairs.  After initial evaluation and treatment by the trauma service, she is moved to the intensive care unit.  Examination reveals a blood pressure of 90/50 mm/Hg, a pulse rate of 50/min, a respiration rate of 12/min, and urine output of 1 mL/kg/h.  Her hemodynamic status should be addressed by

 

1-         continued fluid bolus.

2-         methylprednisolone.

3-         insertion of a Swan-Ganz catheter.

4-         immediate intubation.

5-         beta blockers to decrease peripheral resistance.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: The patient’s heart rate is not responding to hypotension with tachycardia, as would be expected in the event of hypovolemic shock.  Additionally, the adequate urine
output suggests proper fluid resuscitation.  Instead, she is bradycardic, possibly indicating neurogenic shock and loss of sympathetic tone to the heart.  A Swan-Ganz catheter should be used to help differentiate these problems and guide appropriate fluid resuscitation and use of vasopressor agents.

 

REFERENCES: Hadley MN: Management of acute spinal cord injuries in an intensive care unit or other monitored setting.  Neurosurgery 2002;50:S51-S57.

Vaccaro AR, An HS, Betz RR, et al: The management of acute spinal trauma: Prehospital and in-hospital emergency care.  Instr Course Lect 1997;46:113-125.

 

64.    What region of the spine is most susceptible to changes in the vascular supply to the spinal cord during an anterior approach?

 

1-         C7-T1

2-         T1-T3

3-         T4-T7

4-         T8-T12

5-         L1-L3

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The thoracic spinal cord is characterized by a variable and, at times, complicated blood supply.  The artery of Adamkiewicz, also known as the great anterior medullary artery, most typically arises off the left side of the aorta between T8 and T12.  It represents the sole medullary blood supply to the thoracic spine.  When this artery is divided or injured, the blood supply to the thoracic cord may be interrupted.  It is important to avoid electocautery of blood vessels within or near the thoracic foramen because this is a site of important, albeit limited, collateral circulation. 

 

REFERENCES: Sharma M, Anderson FC: Spinal vascular lesions, in Frymoyer JW, Wiesel SW (eds): The Adult and Pediatric Spine.  Philadelphia, PA, Lippincott Williams and Wilkins, 2004, pp 301-306.

Alleyne CH, Cawley CM, Shenglaia GC, et al: Microsurgical anatomy of Adamkiewicz’s artery.  J Neurosurg 1998;89:791-795.

 

65.    What is the most common presenting sign or symptom in an adult with lumbar
pyogenic infection?

 

1-         Fever

2-         Night sweats

3-         Unexplained weight loss

4-         Foot drop

5-         Back pain

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Pain is very common but is often nonspecific; therefore, the diagnosis of spinal infection is often delayed.  Fever and sepsis can occur but are not common.  Neurologic manifestations also can occur but are absent in most patients.  In findings reported by Carragee, the urinary tract is a common source for hematogenous spinal infection, but the source was found in only 27% of 111 patients.  Direct inoculation during spinal surgery is uncommon.

 

REFERENCES: Carragee EJ: Pyogenic vertebral osteomyelitis.  J Bone Joint Surg Am 1997;79:874-880.

Frazier DD, Campbell DR, Garvey TA, et al: Fungal infections of the spine: Report of eleven patients with long-term follow-up.  J Bone Joint Surg Am 2001;83:560-565.

Hadjipavlou AG, Mader JT, Necessary JT, et al: Hematogenous pyogenic spinal infections and their surgical management.  Spine 2000;25:1668-1679.

 

66.    The natural history of cervical spondylolytic myelopathy is best described as

 

1-         slow, steady deterioration.

2-         rapid deterioration.

3-         stable over time.

4-         stable for long periods with stepwise deterioration.

5-         significant improvement after an initial episode of severe symptoms.

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The natural history of cervical myelopathy has been described by Lees and Turner as exacerbations of symptoms followed by often long periods of static or deteriorating function (or very rarely improvement).  This stepwise pattern of decreasing function has been corroborated by Clarke and Robinson.  These authors described long periods of stable neurologic function, sometimes lasting for years, in about 75% of their patients.  In the majority of the patients, however, the condition deteriorated between quiescent streaks.  About 20% of their patients showed a slow, steady progression of symptoms and signs without a stable period, and 5% had rapid deterioration of neurologic function.

 

REFERENCES: Emery SF: Cervical spondylotic myelopathy: Diagnosis and treatment.  J Am Acad Orthop Surg 2001;9:376-388.

Lees F, Turner JA: The natural history and prognosis of cervical spondylosis.  Brit Med J 1963;2:1607-1610.

Clarke E, Robinson PK: Cervical myelopathy: A complication of cervical spondylosis.  Brain 1956;79:486-510.

 

67.    Figures 20a and 20b show lateral and AP radiographs of a 49-year-old man who sustained a gunshot wound through the left shoulder.  He reports neck pain and examination reveals weakness in all four extremities.  What is the priority of evaluation?

 

1-         Detailed neurologic examination

2-         Direct laryngoscopy

3-         Immediate examination of extremities for other possible injuries

4-         Airway, breathing, and circulation

5-         Hemoglobin, hematocrit, and toxicology screening

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The projectile entered the left shoulder and traveled to the right neck; therefore, a high incidence of suspicion must be directed to the airway, great vessels of the neck, and contents of the mediastinum.  Immediate assessment of airway, breathing, and circulation takes priority, followed by examination of the neurologic status and other systems, as determined by the examination findings.   

 

REFERENCES: Subcommittee on ATLS of the American College of Surgeons Committee on Trauma 1993-1997, Spine and Spinal Cord Trauma; Advanced Trauma Life Support Student Manual, ed 6, 1997.

International Standards for Neurological and Functional Classification of Spinal Cord Injury.  American Spinal Injury Association and International Medical Society of Paraplegia (ASIA/IMSOP).

 

68.    A 35-year-old woman undergoes an L4-5 anterior fusion via a left retroperitoneal approach.  Postoperative examination reveals that her right foot is cool and pale.  Her neurologic examination is normal, and her pedal pulses are asymmetric.  What is the most likely reason for the right foot finding?

 

1-         Injury to the lumbar sympathetic chain

2-         Injury to the parasympathetic nerve

3-         Immune response to the allograft bone

4-         Occlusion of the left iliac vein

5-         Prolonged retraction of the left iliac artery

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The lower extremity symptoms are consistent with a sympathectomy that is the result of an injury to the sympathetic chain, ipsilateral to the approach along the anterior border of the lumbar spine.  This results in a warm, red foot, which creates the appearance that the normal cooler foot may have compromised circulation.  The latter generally attracts greater attention because of the risks associated with limb ischemia.  The condition usually is self-limited and does not require any specific treatment. 

 

REFERENCES: Rothman RH, Simeone FA (eds): The Spine, ed 4.  Philadelphia PA, WB Saunders, 1999, p1550.

Benzel EC (ed): Spine Surgery Techniques, Complication Avoidance and Management.  New York, NY, Churchill Livingstone, 1999, p 190.

 

69.    What type of thoracolumbar spinal injury is associated with an increased risk of neurologic deterioration following admission to the hospital?

 

1-         Burst fracture

2-         Senile osteoporotic compression fracture

3-         Chance (seat belt) fracture

4-         Rotational fracture-dislocation

5-         Traumatic L5-S1 spondylolisthesis

 

PREFERRED RESPONSE: 4

 

DISCUSSION: Gertzbein’s Scoliosis Research Society Morbidity and Mortality report noted that neurologic deterioration developed in approximately 16% of patients who were hospitalized with fracture-dislocations of the thoracolumbar spine, a particular concern with rotational burst fractures (AO type C).  Patients with standard burst fractures and Chance fractures had a markedly lower incidence of neurologic involvement and tended to remain neurologically stable.

 

REFERENCES: Gertzbein SD: Neurologic deterioration in patients with thoracic and lumbar fractures after admission to the hospital.  Spine 1994;19:1723-1725.

Magerl F, Aebi M, Gertzbein SD, et al: A comprehensive classification of thoracic and lumbar injuries.  Eur Spine J  1994;3:184-201. 

 

70.    A 30-year-old man has had a 3-day history of severe, incapacitating lower back pain without radiation.  He reports improvement with rest.  He denies any history of trauma, has no constitutional symptoms, and his neurologic examination is normal.  What is the best course of action?

 

1-         Facet injections

2-         Epidural steroid injection

3-         MRI of the lumbar spine

4-         Bed rest for 2 weeks with continued restrictions

5-         Early return to activities as his symptoms allow

 

PREFERRED RESPONSE: 5

 

DISCUSSION: There are no red flags in the history or examination to warrant MRI.  Limited bed rest (less than 3 days) has been shown to be more beneficial to early recovery compared with prolonged bed rest (more than 7 days).  No data support the use of epidural or facet steroid injections for acute low back pain.

 

REFERENCE: Deyo RA, Diehl AK, Rosenthal M: How many days of bed rest for acute low back pain? A randomized clinical trial.  N Engl J Med 1986;315:1064-1070.

 

71.    Which of the following patient factors is associated with recurrent radicular pain following lumbar diskectomy for sciatica?

 

1-         Initial symptoms of more than 3 months’ duration

2-         Large annular defects seen intraoperatively

3-         Large sequestered disk herniations

4-         Initial treatment with lumbar epidural steroid injections prior to diskectomy

5-         Preoperative reproduction of sciatica with straight leg raising (SLR)

 

PREFERRED RESPONSE: 2

 

DISCUSSION: A large annular defect at the site of a lumbar disk herniation is associated with persistent radicular pain postoperatively.  Large sequestered herniations and a positive SLR preoperatively correlate with good outcomes after diskectomy.  Neither symptoms of more than 3 months’ duration nor preoperative epidural steroid injections correlate with postoperative results after diskectomy.

 

REFERENCES: Carragee EJ, Han MY, Suen PW, et al: Clinical outcomes after lumbar discectomy for sciatica: The effects of fragment type and anular competence.  J Bone Joint Surg Am 2003;85:102-108.

Fardon DF, Garfin SR, Abitbol J, et al (eds): Orthopedic Knowledge Update Spine 2.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 323-332.

 

72.    Figure 21 shows the tomogram of a 26-year-old woman who sustained an axial load injury to her neck in a fall off a horse.  What ligament is injured?

 

1-         Anterior longitudinal

2-         Posterior longitudinal

3-         Alar

4-         Apical

5-         Transverse

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Levine and Edwards, in their description of the classic C1 burst (Jefferson) fracture, noted that spread of the lateral masses of more than 7 mm is indicative of a transverse ligament rupture.  Long-term C1-C2 instability, however, has not been described with this fracture pattern.  Although long-term traction followed by halo vest immobilization has been described as the best technique for achieving an ideal result, treatment of this injury remains somewhat controversial.

 

REFERENCES: Levine AM, Edwards CC: Fractures of the atlas.  J Bone Joint Surg Am 1991;73:680-691.

Kurz LT: Fractures of the first cervical vertebra, in Clark CR (ed): The Cervical Spine, ed 3.  Philadelphia, PA, Lippincott Raven, 1998, pp 409-413.

 

73.    Based on the findings shown in Figures 22a and 22b, corrective surgery to obtain maximal safe correction and optimal instrumentation fixation should be performed at which of the following locations?

 

1-         Lower cervical spine

2-         Midthoracic spine

3-         Thoracolumbar junction

4-         Midlumbar spine

5-         Lumbosacral junction

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The clinical photograph and radiograph show an iatrogenic flatback deformity with loss of the normal lumbar lordosis.  The safest correction for this malalignment typically is performed away from the spinal cord in the midlumbar spine, most commonly at L2 or L3.  The more distal the correction is performed, the more sagittal plane translation of the C7 plumb line with respect to the posterior sacrum.  Performing the osteotomy too distally, however, makes it difficult to obtain adequate distal fixation.

 

REFERENCES: Shufflebarger HL, Clark CE: Thoracolumbar osteotomy for postsurgical sagittal imbalance.  Spine 1992;17:S287-S290.

Murrey DB, Brigham CD, Kiebzak GM, et al: Transpedicular decompression and pedicle subtraction osteotomy (eggshell procedure): A retrospective review of 59 patients.  Spine 2002;27:2338-2345.

 

74.    A 65-year-old woman has significant neck pain after falling and striking her head.  A radiograph and sagittal CT scan are shown in Figures 23a and 23b.  What is the most likely diagnosis?

 

1-         Degenerative spondylolisthesis

2-         Superior facet fracture

3-         Inferior facet fracture

4-         Perched unilateral facet dislocation

5-         Bilateral facet dislocation

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The radiograph shows a displacement of C5 on C6 of approximately 25%.  The CT scan shows a perched facet at C5-6.  There is no evidence of a facet fracture.  A bilateral facet dislocation would show a displacement of more than 50%.

 

REFERENCES: Rothman RH, Simeone FA (eds): The Spine, ed 4.  Philadelphia PA, WB Saunders, 1999, pp 927-937.

Vaccaro AR, Betz RR, Zeidman SM (eds): Principles and Practice of Spine Surgery.  St Louis, MO, Mosby, 2003, pp 455-458.

 

75.    Immediately after undergoing lumbar instrumentation, a patient reports severe right leg pain and has 4+/5 weakness.  Figure 24 shows an axial CT scan of L5.  Exploratory surgery will most likely reveal

 

1-         transection of the L5 root.

2-         displacement of the L5 root.

3-         partial laceration of the L5 root.

4-         segmental artery injury.

5-         spinal fluid leakage.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The most common finding at exploration of an inappropriately placed pedicle screw is displacement of the nerve.  Pedicle breach is common, ranging from 2% to 20%, but most are asymptomatic.  All of the choices are possible, but in a large series conducted by Lonstein and associates, the authors reported that displacement of the root, most often medial, was the most common finding.  Laceration, contusion, or transfixion usually was not seen.  Spinal fluid leakage occurs less frequently and is not expected in the minimal broach illustrated.

 

REFERENCES: Esses SI, Sachs BL, Dreyzin V: Complications associated with the technique of pedicle screw fixation: A selected survey of ABS members.  Spine 1993;18:2231-2238.

Laine T, Lund T, Ylikoski M, et al: Accuracy of pedicle screw insertion with and without computer assistance: A randomised controlled clinical study in 100 consecutive patients.  Eur Spine J 2000;9:235-240.

Lonstein JE, Denis F, Perra JH, et al: Complications associated with pedicle screws.  J Bone Joint Surg Am 1999;81:1519-1528.

 

76.    Figures 25a and 25b show the radiograph and MRI scan of a 48-year-old man who reports increasing unsteadiness in his gait and hand clumsiness.  Examination reveals a positive Hoffmann’s reflex bilaterally, positive clonus, and a spastic gait.  Management should consist of

 

1-         cervical laminoplasty at C3-C7.

2-         anterior corpectomy at C4, with a C3-C5 fibular strut.

3-         epidural steroids and physical therapy for cervical traction.

4-         multilevel cervical anterior diskectomy and fusion.

5-         observation for progression over the next few months.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The patient has a congenitally small spinal canal with secondary multilevel degenerative changes causing stenosis and cord compression across multiple segments,
including directly posterior to the vertebral bodies.  A multilevel diskectomy may address the cord compression at the disk level, but not posterior to the bodies, and most likely would be inadequate.  The patient has significant stenosis distal to C5, necessitating a more extensive surgical approach than simply C3-C5.  Because the patient’s cervical lordosis is preserved, a posterior procedure such as laminoplasty or laminectomy would allow the cord to fall away
from the anterior pathology and afford decompression.  Cervical myelopathy does not tend to resolve, and there is a significant risk for progression; therefore, surgical management usually
is recommended.

 

REFERENCES: Edwards CC II, Riew KD, Anderson PA, et al: Cervical myelopathy: Current diagnostic and treatment strategies.  Spine J 2003;3:68-81.

Edwards CC II, Heller JG, Murakami H: Corpectomy versus laminoplasty for multilevel cervical myelopathy: An independent matched-cohort analysis.  Spine 2002;27:1168-1175.

 

77.    Lumbar disk replacement has been shown to offer which of the following results?

 

1-         Provides long-term pain relief superior to that achieved with lumbar fusion

2-         Provides long-term pain relief equivalent to that achieved with lumbar fusion

3-         Provides long-term pain relief in patients with symptomatic degenerative disk disease and facet arthropathy

4-         Consistently prevents the development of adjacent segment disease

5-         Consistently restores normal segmental motion

 

PREFERRED RESPONSE: 2

 

DISCUSSION: There is no clear evidence that disk replacement results in pain relief that is superior to fusion.  Pain relief appears to be equivalent with these two procedures.  No study has clearly demonstrated that normal segmental motion has been consistently restored.  Preexisting facet arthropathy is considered to be a contraindication to disk replacement.  Comparative long-term data demonstrating a reduced incidence of adjacent segment disease compared to fusion are not yet available.

 

REFERENCES: Geisler FH, Blumenthal SL, Guyer RD, et al: Neurological complications of lumbar artificial disc replacement and comparison of clinical results with those related to lumbar arthrodesis in the literature.  J Neurosurg Spine 2004;1:143-154.

Tropiano P, Huang RC, Girardi FP, et al: Lumbar total disc replacement:  Seven to eleven-year follow-up.  J Bone Joint Surg Am 2005;87:490-496.

 

78.    When performing the exposure for an anterior approach to the cervical spine, the surgical dissection should not enter the plane between the trachea and the esophagus and excessive retraction should be avoided to prevent injury to the

 

1-         vagus nerve.

2-         recurrent laryngeal nerve.

3-         superior laryngeal nerve.

4-         hypoglossal nerve.

5-         sympathetic trunk.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The recurrent laryngeal nerve lies between the trachea and the esophagus.  The vagus nerve lies in the carotid sheath.  The sympathetic trunk lies anterior to the longus colli muscles.  The hypoglossal and superior laryngeal nerves are both at risk during the exposure but are not located between the trachea and the esophagus.

 

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

Patel CK, Fischgrund JS: Complications of anterior cervical spine surgery.  Instr Course Lect 2003;52:465-469.

 

79.    A 39-year-old man reports low back pain, lower extremity numbness, and urinary retention after being injured in a motor vehicle accident 1 day ago.  He is able to walk but is in pain.  A straight leg raise results in increased back pain, and examination reveals that perianal sensation is decreased.  Placement of a urinary catheter results in 500 mL of urine.  What is the next most appropriate step in management?

 

1-         Emergent MRI

2-         Urology consultation

3-         Pain control with narcotics

4-         Pain control with a lumbar epidural steroid injection

5-         Physical therapy

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Acute cauda equina syndrome, including saddle hypesthesia and bowel/bladder incontinence, is a red flag that demands emergent evaluation with MRI and urgent surgery if compression is confirmed.  Results appear to be improved if surgery is performed within 48 hours.  The other treatment approaches listed are not indicated if a cauda equina syndrome
is present.

 

REFERENCES: Ahn UM, Ahn NU, Buchowski JM, et al: Cauda equina syndrome secondary to lumbar disc herniation: A meta-analysis of surgical outcomes.  Spine 2000;25:1515-1522.

Shapiro S: Medical realities of cauda equina syndrome secondary to lumbar disc herniation.  Spine 2000;25:348-351.

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

 

80.    Figures 26a and 26b show the radiograph and MRI scan of an 18-year-old man who fell from a trampoline.  Examination reveals exquisite local tenderness at the thoracolumbar junction, but he is neurologically intact.  Management should consist of

 

1-         posterior fusion with instrumentation.

2-         posterior instrumentation without fusion.

3-         anterior fusion with instrumentation.

4-         an orthosis.

5-         bed rest with gradual mobilization.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Based on the radiographic findings of marked disruption of the posterior ligamentous complex with a relatively small anterior bony fracture, the patient has a classic Chance-type ligamentous flexion-distraction injury.  The pathology is mostly in soft tissues with limited healing potential.  The treatment of choice is posterior reconstruction of the tension band with a short segment fusion with instrumentation.  Casting or bracing may result in a painful kyphosis with ligamentous insufficiency.  The anterior bony column is mostly intact, so anterior reconstruction is not necessary.

 

REFERENCES: Carl AL: Adult spine trauma, in DeWald RL (ed): Spinal Deformities: A Comprehensive Text.  New York, NY, Thieme, 2003, pp 406-423.

Lewandrowski KU, McLain RF: Thoracolumbar fractures: Evaluation, classification, and treatment, in Frymoyer JW, Wiesel SW (eds): The Adult and Pediatric Spine.  Philadelphia, PA, Lippincott Williams and Wilkins, 2004, pp 817-843. 

 

81.    A 17-year-old high school football player is seen for follow-up after sustaining an injury 3 days ago.  He reports that he tackled a player, felt numbness throughout his body, and could not move for approximately 15 seconds.  A spinal cord injury protocol was initiated on the field.  Evaluation in the emergency department revealed a normal neurologic examination and full painless neck motion.  He states that he has no history of a similar injury.  An MRI scan of the cervical spine is normal.  During counseling, the patient and his family should be informed that he has sustained

 

1-         a spinal cord injury and he cannot participate in contact sports.

2-         no obvious injury and can return to all sports without risk of recurrence.

3-         no obvious injury, but he is at a high risk for breaking his neck in athletic competition.

4-         transient quadriplegia only, but this places him at greater risk for future spinal cord injury and he should refrain from all contact sports.

5-         transient quadriplegia and that there is no evidence of increased risk of permanent spinal cord injury should he return to contact sports.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The long-term effect of transient quadriplegia is unknown.  Based on a history of one brief episode of transient quadriplegia and normal examination and MRI findings, the risk of permanent spinal cord injury with a return to play is low.  There is a risk of recurrent episodes of transient quadriplegia after the initial episode.

 

REFERENCES: Morganti C, Sweeney CA, Albanese SA, et al: Return to play after cervical spine injury.  Spine 2001;26:1131-1136.

Odor JM, Watkins RG, Dillin WH, et al: Incidence of cervical spinal stenosis in professional and rookie football players.  Am J Sports Med 1990;18:507-509.

Torg JS, Naranja RJ Jr, Palov H, et al: The relationship of developmental narrowing of the cervical spinal canal to reversible and irreversible injury of the cervical spinal cord in football players.  J Bone Joint Surg Am 1996;78:1308-1314.

Vaccaro AR, Watkins B, Albert TJ, et al: Cervical spine injuries in athletes: Current return-to-play criteria.  Orthopedics 2001;24:699-703.

 

82.    Which of the following is considered a contraindication to cement injection
techniques, such as kyphoplasty or vertebroplasty, in the treatment of osteoporotic compression fractures?

 

1-         Patient age of more than 85 years

2-         Retropulsion of the posterior vertebral wall

3-         Acute fracture in a hospitalized patient

4-         Prior compression fracture

5-         Fracture age of 4 months

 

PREFERRED RESPONSE: 2

 

DISCUSSION: When retropulsion of the posterior vertebral wall is present, nothing prohibits the cement from following the path of least resistance into the canal or from pushing a bone fragment further into the canal; most clinicians consider it a contraindication to these techniques.  Patient age itself is not a contraindication as long as there are no medical contraindications to surgery.  An acute fracture in a patient who remains immobile and hospitalized because of pain may be a good indication for such a technique.  Prior compression fracture and older compression fractures are not contraindications, but pain relief may be less predictable.

 

REFERENCES: Phillips FM, Pfeifer BA, Leiberman IH, et al: Minimally invasive treatment of osteoporotic vertebral compression fractures: Vertebroplasty and kyphoplasty.  Instr Course Lect 2003;52:559-567.

Truumees E, Hilibrand A, Vaccaro AR: Percutaneous vertebral augmentation.  Spine J 2004;4:218-229.

Rao RD, Singrakhia MD: Painful osteoporotic vertebral fracture: Pathogenesis, evaluation, and roles of vertebroplasty and kyphoplasty in its management.  J Bone Joint Surg Am 2003;85:2010-2022.

 

83.    Chronic anterior donor site pain following the harvest of autologous iliac crest bone graft for use during anterior cervical diskectomy and fusion is reported by approximately what percent of patients?

 

1-         Less than 1%

2-         5%

3-         25%

4-         50%

5-         75%

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Four years after surgery, more than 90% of patients are satisfied with the cosmetic appearance of the iliac donor site scar.  Approximately 25% still have pain and/or functional difficulty, including 12.7% who still report difficulty with ambulation, 11.9% difficulty with recreational activities, 7.5% with sexual intercourse, and 11.2% require pain medication for iliac donor site symptoms.

 

REFERENCES: Silber JS, Anderson DG, Daffner SD, et al: Donor site morbidity after anterior iliac crest bone harvest for single-level anterior cervical discectomy and fusion.  Spine 2003;28:134-139.

Cockin J: Autologous bone-grafting complications at the donor site.  J Bone Joint Surg Br 1971;49:153.

 

84.    When treating osteoporosis with alendronate, what is the most common side effect?

 

1-         Diarrhea

2-         Epigastric distress

3-         Dry mucous membranes

4-         Drowsiness

5-         Insomnia

 

PREFERRED RESPONSE: 2

 

DISCUSSION: Alendronate is a second-generation bisphosphonate, and it can cause epigastric distress in up to 30% of patients.  This side effect can be minimized by gradually building up to therapeutic doses over a period of 4 to 8 weeks.

 

REFERENCES: Marshall JK, Rainsford KD, James C, et al: A randomized controlled trial to assess alendoronate-associated injury of the upper gastrointestinal tract.  Aliment Pharmacol Ther 2000;14:1451-1457.

Lane JM, Sandhu HS: Osteoporosis of the spine, in Garfin SR, Vaccaro AR (eds): Orthopaedic Knowledge Update: Spine.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 1997, pp 227-234.

 

85.    Figures 27a and 27b show the radiographs of a 32-year-old woman who was involved in a high-speed motor vehicle accident.  She is neurologically intact.  After stabilization and assessment, treatment should consist of

 

1-         measurement for a thoracolumbosacral orthosis.

2-         bed rest with gradual mobilization.

3-         anterior corpectomy and interbody fusion with instrumentation.

4-         kyphoplasty.

5-         posterior fusion with instrumentation.

 

PREFERRED RESPONSE: 5

 

DISCUSSION: The radiographs show a fracture-dislocation with translation in both the coronal and sagittal planes, evidence of significant instability requiring surgical stabilization.  Anterior instrumentation is not as effective as posterior instrumentation in restoring stability, and because there is little bony destruction, the anterior column can be successfully reconstructed with simple realignment.  The treatment of choice is multisegment posterior fusion with instrumentation.

 

REFERENCES: Lewandrowski KU, McLain RF: Thoracolumbar fractures: Evaluation, classification, and treatment, in Frymoyer JW, Wiesel SW (eds): The Adult and Pediatric Spine.  Philadelphia, PA, Lippincott Williams and Wilkins, 2004, pp 817-843. 

Carl AL: Adult spine trauma, in DeWald RL (ed): Spinal Deformities: A Comprehensive Text.  New York, NY, Thieme, 2003, pp 406-423.

 

86.    Figures 28a through 28c show the MRI scans of a 30-year-old woman who weighs
290 lb and has low back and left leg pain.  She also reports frequent urinary dribbling, which her gynecologist has advised her may be related to obesity.  Examination will most likely reveal

 

1-         ipsilateral weakness of the tibialis anterior.

2-         ipsilateral weakness of the peroneus longus and brevis.

3-         ipsilateral weakness of the extensor hallucis longus.

4-         a positive Beevor’s sign.

5-         a positive ipsilateral Gaenslen’s sign.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The patient will most likely exhibit ipsilateral weakness of the tibialis anterior.  Gaenslen’s test is designed to detect sacroiliac inflammation as a source of low back pain.  Beevor’s sign tests the innervation of the rectus abdominus and paraspinal musculature (L1 innervation).  The extensor hallucis longus is predominantly innervated by L5.  The peroneals are predominantly innervated by S1.

 

REFERENCES: Hoppenfeld S: Physical Examination of the Spine and Extremities.  Appleton, WI, Century-Crofts, 1976. 

Hollinshead WH (ed): Anatomy for Surgeons: The Back and the Limbs, ed 3.  Philadelphia, PA, Harper & Rowe, 1982.

 

87.    Which of the following statements regarding conus medullaris syndrome is
most accurate?

 

1-         Conus medullaris syndrome most commonly accompanies injuries at the T12-L2 region.

2-         Conus medullaris injury is a lower motor neuron injury, resulting in an excellent prognosis for recovery of bowel and bladder dysfunction.

3-         The conus medullaris houses the motor cell bodies for the lumbar roots.

4-         Lower extremity weakness is a common sign of conus medullaris syndrome.

5-         Autonomic dysreflexia is common.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Conus medullaris syndrome most frequently occurs as a result of trauma or with a disk herniation at L1, resulting in a lower motor neuron syndrome but with a poor prognosis for recovery of bowel and bladder dysfunction.  The conus region, as the termination of the spinal cord, contains the motor cell bodies of the sacral roots.  The syndrome is usually a sacral level neural injury; therefore, lower extremity weakness is uncommon.

 

REFERENCES: Haher TR, Felmly WT, O’Brien M: Thoracic and lumbar fractures: Diagnosis and management, in Bridwell KH, Dewald RL, Hammerberg KW, et al (eds): The Textbook of Spinal Surgery, ed 2.  New York, NY, Lippincott Williams & Wilkins, 1977, pp 1773-1778.

Reitman CA (ed): Management of Thoracolumbar Fractures.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 35-45. 

 

88.    Which of the following factors has the greatest effect on the pull-out strength of a lumbar pedicle screw?

 

1-         Depth of vertebral body penetration

2-         Percentage of pedicle filled by the screw

3-         Bone mineral density

4-         Tapping of the pedicle

5-         Screw diameter

 

PREFERRED RESPONSE: 3

 

DISCUSSION: All of the factors listed contribute to some extent to the pull-out strength of lumbar pedicle screws, but bone mineral density correlates most precisely.

 

REFERENCES: Wittenberg RH, Shea M, Swartz DE, et al: 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.

 

89.    An inverted radial reflex is associated with

 

1-         spinal cord compression with myelopathy.

2-         acute cervical radiculopathy.

3-         chronic cervical radiculopathy.

4-         Parsonage-Turner syndrome.

5-         peripheral neuropathy.

 

PREFERRED RESPONSE: 1

 

DISCUSSION: An inverted radial reflex is a hypoactive brachioradialis reflex in combination with involuntary finger flexion.  It is a spinal cord “release” sign and is associated with upper motor neuron pathology as seen in cervical stenosis with myelopathy.  Radiculopathy is characterized by a diminished reflex but no finger flexion.  Peripheral neuropathy is not associated with any reflex change.  Parsonage-Turner syndrome is an idiopathic brachial neuritis.

 

REFERENCES: Clark CR (ed): The Cervical Spine, ed 3.  Philadelphia, PA, Lippincott Williams & Wilkins, 1998, p 762.

Vaccaro AR, Betz RR, Zeidman SM (eds): Principles and Practice of Spine Surgery.  St Louis, MO, Mosby, 2002, p 323.

 

90.    Figures 29a and 29b show the radiograph and CT scan of a 48-year-old man who has diffuse spinal pain.  What is the most likely diagnosis?

 

1-         Rheumatoid arthritis

2-         Diffuse idiopathic skeletal hyperostosis (DISH)

3-         Normal findings

4-         Ankylosing spondylitis

5-         Osteopetrosis

 

PREFERRED RESPONSE: 4

 

DISCUSSION: The studies show marginal syndesmophyte formation characteristic of ankylosing spondylitis.  These patients typically have diffuse ossification of the disk space without large osteophyte formation.  DISH typically presents with large osteophytes, referred to as nonmarginal syndesmophytes.  In this patient, the zygoapophyseal joints are fused rather than degenerative as would be seen in rheumatoid arthritis, and the costovertebral joints are also fused. Osteopetrosis does not normally ankylose the disk space.

 

REFERENCES: McCullough JA, Transfeldt EE: Macnab’s Backache, ed 3.  Baltimore, MD, Williams and Wilkins, 1997, pp 190-194.

Frymoyer JW, Wiesel SW (eds):  The Adult and Pediatric Spine, ed 3.  Philadelphia, PA, Lippincott, Williams and Wilkins, 2003, pp 141-151.

 

91.    The cervical disk herniation shown in the MRI scans in Figures 30a and 30b will most likely create which of the following constellations of symptoms?

 

1-         Right thumb and index finger numbness and triceps weakness

2-         Right thumb and index finger numbness and wrist extensor weakness

3-         Right wrist extensor weakness and diminished triceps reflex

4-         Right middle finger numbness and diminished brachioradialis reflex

5-         Right little and ring finger numbness and diminished brachioradialis reflex

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The MRI scans reveal a right-sided C5-6 herniated nucleus pulposus.  A disk herniation in this region encroaches on the C6 root and is accompanied by a sensory change along the thumb and index finger, alterations in the brachioradialis reflex, and possible wrist extension weakness.  Although the nerve root associated with the vertebral body passes above the pedicles such that the C6 root passes above the C6 pedicle, it is still the C6 root that is encroached on because the herniation affects the exiting root rather than the traversing root as seen in the lumbar spine.

 

REFERENCES: Klein JD, Garfin SR: Clinical evaluation of patients with suspected spine problems, in Frymoyer JW (ed): Adult Spine: Principles and Practice, ed 2.  Philadephia, PA, Lippincott-Raven, 1997, pp 319-330.

Hoppenfeld S: Orthopaedic Neurology.  Philadelphia, PA, JB Lippincott, 1977, pp 7-49.

 

92.    A 21-year-old man has had posterior neck discomfort for the past 6 months.  A whole-body bone scan and a cervical single-photon emission CT reveal increased activity at the C7 spinous process. MRI reveals multifocal involvement of the spinous process lamina and facet of C7.  A CT-directed needle biopsy reveals osteoblastoma.  What is the best course of action?

 

1-         Observation

2-         Radiation therapy

3-         Curettage

4-         En bloc excision with stabilization

5-         En bloc excision followed by radiation therapy

 

PREFERRED RESPONSE: 4

 

DISCUSSION: En bloc excision is the recommended treatment of osteoblastoma. Treatment should consist of en bloc removal of the lamina, facet, and spinous process.  Facet removal would necessitate fusion. Radiation therapy is not recommended. Intralesional curettage has a high rate of recurrence.

 

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.

Ozaki T, Liljenquist U, Hillmann A, et al: Osteoid osteoma and osteoblastoma of the spine: Experience with 22 patients.  Clin Orthop 2002;397:394-402.

 

93.    What is the most likely consequence of a vertebral compression fracture associated
with osteoporosis?

 

1-         The fractured vertebral body gradually becomes more stiff than before the fracture.

2-         Scoliosis develops.

3-         There is an increased risk of more vertebral fractures.

4-         Overall sagittal alignment remains stable because the adjacent segments of the spine are able to compensate.

5-         The extensor musculature will often hypertrophy in an attempt to stabilize the painful fracture.

 

PREFERRED RESPONSE: 3

 

DISCUSSION: After an osteoporotic vertebral compression fracture, the risk of subsequent fractures at adjacent levels increases.  This is felt to be the result of a shifting of the sagittal alignment more anteriorly, putting more stress on the osteopenic vertebral bodies and their anterior cortices.  Pain generally resolves with rest, but this may take weeks or months.  It has been demonstrated experimentally that osteoporotic vertebral bodies are actually less stiff and weaker after a compression fracture; therefore, deformity predisposes to further deformity.  The extensor musculature often fatigues over time and usually does not hypertrophy.  Frontal plane deformity is a rare development.

 

REFERENCES: Heaney RP: The natural history of vertebral osteoporosis: Is low bone mass an epiphenomenon?  Bone 1992;13:S23-S26.

Tohmeh AG, Mathias JM, Fenton DC, et al: Biomechanical efficacy of unipedicular versus bipedicular vertebroplasty for the management of osteoporotic compression fractures.  Spine 1999;24:1772-1776.

 

94.    What is the most appropriate treatment for a chordoma involving the sacrum?

 

1-         Chemotherapy

2-         External beam radiation therapy

3-         En bloc surgical resection with negative margins

4-         Intralesional resection followed by radiation therapy

5-         Intralesional resection followed by chemotherapy

 

 

PREFERRED RESPONSE: 3

 

DISCUSSION: Chordomas are very radio- and chemotherapy resistant; therefore, en bloc resection with a negative margin is the preferred treatment.  Lesions at or below S3 can be resected without compromising pelvis stability, and continence usually is maintained.  The mean survival rate for patients with sacral chordomas is approximately 7 years.  Patients with chordoma of the mobile (cervical, thoracic, or lumbar) spine have a mean survival rate of approximately 5 years.  This difference is most likely the result of an earlier diagnosis.

 

REFERENCES: Fardin DF, Garfin SR, Abitbol J, et al (eds): Orthopaedic Knowledge Update: Spine 2.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 123-133.

Stener B, Gunterberg B: High amputation of the sacrum for extirpation of tumors: Principles and technique.  Spine 1978;3:351-366.

Stener B: Resection of the sacrum for tumors.  Chir Organi Mov 1990;75:S108-S110.

 

95.    A 62-year-old woman has back pain and right L2 radicular pain.  MRI scans suggest a neoplastic lesion at L2, and a bone scan is negative except at L2.  History reveals that she was treated for breast cancer without known metastatic disease 12 years ago and is thought to be free of disease.  What is the next most appropriate step in management?

 

1-         CT-guided biopsy

2-         Anterior intralesional corpectomy and fusion

3-         Anteroposterior fusion with en bloc resection

4-         Radiation therapy

5-         Repeat MRI in 3 months

 

PREFERRED RESPONSE: 1

 

DISCUSSION: Because of the long disease-free interval, it cannot be assumed that this is breast cancer.  The lesion could represent metastasis from a new primary tumor or could itself be a primary tumor.  CT-guided biopsy will most effectively identify the lesion and guide treatment options.  Depending on the specific diagnosis, any of the other options may be appropriate.

 

REFERENCE: Fardin DF, Garfin SR, Abitbol J, et al (eds): Orthopaedic Knowledge Update: Spine 2.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 411-430.

 

96.    A 60-year-old woman with rheumatoid arthritis has atlanto-axial instability and basilar invagination.  What MRI findings would suggest the need for cervical fusion?

 

1-         Cervical medullary angle of 125°

2-         Space available for the cord of 15 mm

3-         Cord diameter in flexion of 10 mm

4-         C3-4 subluxation of 2 mm

5-         Erosion of the tip of the odontoid

 

PREFERRED RESPONSE: 1

 

DISCUSSION: The cervical medullary junction should be 135° or greater.  An angle of 125° suggests compression of the cervical medullary junction.  Other findings supporting surgical intervention include a cord diameter in flexion of less than 6 mm or less than 13 mm of space available for the cord.

 

REFERENCES: Clark CR (ed): The Cervical Spine, ed 3.  Philadelphia, PA, Lippincott Williams & Wilkins, 1998, pp 700-701.

Monsey RB: Rheumatoid arthritis of the cervical spine.  J Am Acad Orthop Surg
1997;5:240-248.

Bundschuh C, Modic MT, Kearney F, et al: Rheumatoid arthritis of the cervical spine: Surface-coil MR imaging.  Am J Roentgenol 1988;151:181-187.

 

97.    Which of the following statements is most accurate regarding undetected intraoperative surgical glove perforation?

 

1-         Undetected intraoperative surgical glove perforation is rare.

2-         The index finger and left hand are the most common sites of surgical
glove perforation.

3-         The primary surgeon is more likely to sustain an undetected surgical
glove perforation, as opposed to the scrub nurse or surgical assistant.

4-         Surgical time is not related to the frequency of surgical glove perforation.

5-         Undetected surgical glove perforation is rare in surgeries lasting 3 hours
or longer.

 

PREFERRED RESPONSE: 2

 

DISCUSSION: The incidence of undetected intraoperative surgical glove perforation has been demonstrated at approximately 8.5%, occurring most frequently on the index finger or left hand of the assistant surgeon.  The frequency of glove perforation is higher in surgeries lasting longer than 3 hours.

 

REFERENCES: Al-Habdan I, Sadat-Ali M: Glove perforation in pediatric orthopaedic practice.  J Pediatr Orthop 2003;23:791-793.

Sadat-Ali M, Al-Othman A: Glove perforations in orthopaedic practice.  Saudi Med J 1996;17:811-813.

 

98.    Which of the following is NOT considered a risk factor for nonunion of a type II odontoid fracture?

 

1-         More than 6 mm of initial displacement

2-         Patient age older than 60 years

3-         Smoking

4-         Inability to achieve reduction

5-         Obesity

 

PREFERRED RESPONSE: 5

 

DISCUSSION: Although obesity can make brace or halo wear difficult, it has not been associated with an increased risk for nonunion.

 

REFERENCES: Carson GD, Heller JG, Abitbol JJ, et al: Odontoid fractures, in Levine AM, Eismont FJ, Garfin SR, et al (eds): Spine Trauma.  Philadelphia, PA, WB Saunders, 1998,
pp 235-238.

Fardin DF, Garfin SR, Abitbol J, et al (eds): Orthopaedic Knowledge Update: Spine 2.  Rosemont, IL, American Academy of Orthopaedic Surgeons, 2002, pp 247-262.

 

99.    A 27-year-old woman has a bilateral C5-C6 facet dislocation and quadriparesis after being involved in a motor vehicle accident.  Initial management consisted of reduction with traction, but she remains a Frankel A quadriplegic.  To facilitate rehabilitation, surgical stabilization and fusion is planned.  From a biomechanical point of view, which of the following techniques is the LEAST stable method of fixation?

 

1-         Anterior cervical plating with interbody bone graft

2-         Posterior cervical plating with lateral mass screw fixation

3-         Posterior sublaminar wiring

4-         Simple posterior interspinous wiring

5-         Bohlman interspinous wiring

 

PREFERRED RESPONSE: 1

 

DISCUSSION: In two different biomechanical studies performed in both bovine and human cadaveric spines, all posterior techniques of stabilization were found to be superior to anterior plating in flexion-distraction injuries of the cervical spine.  These injuries usually have an intact anterior longitudinal ligament that allows posterior fixation to function as a tension band.  Anterior plating with grafting destroys this last remaining stabilizing structure and does not allow for a tension band effect because all of the posterior stabilizing structures have been destroyed with the injury.  In clinical practice, however, anterior plating can be effective in the treatment of this injury with appropriate postoperative orthotic management.

 

REFERENCES: Sutterlin CE III, McAfee PC, Warden KE, et al: A biomechanical evaluation of cervical spine stabilization methods in a bovine model: Static and cyclical loading.  Spine 1988;13:795-802.

Coe JD, Warden KE, Sutterlin CE III, et al: Biomechanical evaluation of cervical spine stabilization methods in a human cadaveric model.  Spine 1989;14:1122-1131.

 

100.  Which of the following findings is considered a poor prognostic factor for postoperative neurologic recovery in patients with rheumatoid arthritis?

 

1-         Anterior atlantoaxial interval of more than 5 mm

2-         Subaxial subluxation of more than 3.5 mm

3-         Subaxial subluxation and space available for the cord equal to 14 mm

4-         Cervicomedullary angle of 135°

5-         Posterior atlantoaxial interval that is less than or equal to 10 mm

 

PREFERRED RESPONSE: 5

 

DISCUSSION: When markedly diminished space available for the cord (demonstrated by a posterior atlantoaxial interval of less than 10 mm) is seen, there is a poor prognosis for recovery (25% of Ranawat class IIIb patients) following surgery.  A posterior atlantoaxial interval of 14 mm or less is a predictor of increased risk of paralysis, but patients with an interval between 10 mm and 14 mm have a greater chance of recovery.  Space available for the cord that is at least 14 mm is not associated with an increased risk of neurologic deficit.

 

REFERENCES: Boden SD, Dodge LD, Bohlman HH, et al: 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.

Casey AT, Crockard HA, Bland JM, et al: Predictors of outcome in the quadriparetic nonambulatory myelopathic patient with rheumatoid arthritis: A prospective study of 55 surgically treated Ranawat Class IIIb patients.  J Neurosurg 1996;85:574-581.

 

 

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