This practice set contains high-yield board review questions covering key concepts in 6. Spine. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.
Question 2081
Topic: 6. Spine
Retrograde ejaculation is most commonly associated with what surgical approach?
Correct Answer & Explanation
. Anterior transperitoneal approach to L5-S1
Explanation
DISCUSSION: Retrograde ejaculation is the sequela of an injury to the superior hypogastric plexus. This structure needs protection, especially during anterior exposure of the lumbosacral junction. Although the superior hypogastric plexus can be injured with anterior or anterolateral spine surgery at any lumbar level, it is most at risk with anterior transperitoneal approaches to the lumbosacral junction. To avoid this complication, the use of monopolar electrocautery should be avoided during deep dissection in this region. The ideal anterior 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. 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. 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.
Question 2082
Topic: 6. Spine
When compared to smokers who do not quit, an improvement in the rate of lumbar fusion is seen in patients who cease smoking for at least how many months postoperatively? Review Topic
Correct Answer & Explanation
. 1 month
Explanation
The effects of cigarette smoking and smoking cessation on spinal fusion have been studied extensively. Although permanent smoking cessation is ideal, significant improvements in fusion rates are seen in patients who avoid smoking for greater than 6 months postoperatively.
Question 2083
Topic: 6. Spine
A 55-year-old woman with a long history of low back and left lower extremity pain has failed to respond to exhaustive nonsurgical management. MRI scans show bulging and degeneration at L3-4 and L4-5 as well as a normal disk at L2-3 and L5-S1. She undergoes provocative lumbar diskography at L3-4, L4-5, and L5-S1. Post-diskography axial CT images of L3-4 and L4-5 are shown in Figures 6a and 6b, respectively. The injections at L3-4 and L4-5 produce no pain. The injection at L5-S1 produces 10/10 concordant back pain with radiation to the lower extremity. What is the most appropriate recommendation at this time?
Correct Answer & Explanation
. Consider fusion surgery
Explanation
DISCUSSION: The results of this patient’s lumbar diskography are equivocal at best. The two disks most likely to be her pain generators, based on their MRI appearance, produced 10/10 pain, however it was nonconcordant and did not reproduce any of her typical left-sided radicular symptoms. The only disk that produced concordant back pain was the normal disk at the L5-S1 level and it reproduced radicular symptoms on the side opposite of her typical pain. Based on these findings, it would be difficult to select a level or levels to include in a lumbar fusion. As such, continued nonsurgical management is the safest treatment option at the current time. Brox and associates reported on a randomized clinical trial comparing lumbar fusion to cognitive intervention and exercise and found similar results in both groups, with significantly less risk in the latter.REFERENCES: Brox JI, Sorensen R, Friis A, et al: Randomized clinical trial of lumbar instrumented fusion and cognitive intervention and exercises in patients with chronic low back pain and disc degeneration. Spine 2003;28:1913-1921.Carragee EJ: Clinical practice: Persistent low back pain. N Engl J Med 2005;352:1891-1898.
Question 2084
Topic: 6. Spine
The MRI scan shown in Figure 24 reveals a right-sided herniated nucleus pulposus at L4-5 in a patient with pain in the right leg. Administration of a caudal epidural steroid injection provides immediate relief. Over the next week he notes generalized weakness of the lower extremities and has one episode of urinary incontinence. What is the next most appropriate step in management?
Correct Answer & Explanation
. Nonsteroidal anti-inflammatory drugs and reassurance that this is a steroid flare reaction that should subside within 2 to 3 days
Explanation
DISCUSSION: Whenever a patient’s condition changes following a test or a procedure, the physician must determine the cause. A steroid flare reaction will not cause incontinence or weakness of the lower extremities. An L4-5 diskectomy may alleviate the problem if the right-sided L4-5 disk herniation is the etiology of the symptoms. However, it is unlikely that a right-sided disk herniation alone will cause a cauda equina syndrome. Possible etiologies include a further extrusion of a disk fragment at L4-5 that now obliterates the spinal canal, a disk herniation at another level, or an epidural abscess following injection of corticosteroids through a caudal approach. In the presence of a possible infection, myelography should not be performed from a lumbar puncture. The fastest and least invasive way to make an appropriate diagnosis is to obtain an MRI of the lumbar spine. In this patient, the MRI revealed an epidural abscess that was compressing the cauda equina. Because of the large dose of steroids that were injected, the patient did not manifest symptoms such as fevers and chills until late in the course.REFERENCES: Knight JW, Cordingley JJ, Palazzo MG: Epidural abscess following epidural steroid and local anaesthetic injection. Anaesthesia 1997;52:576-578.Abram SE, O’Connor TC: Complications associated with epidural steroid injections. Reg Anesth 1996;21:149-162.
Question 2085
Topic: 6. Spine
4 mg/kg for 48 hours
Correct Answer & Explanation
. Administration of naloxone with an initial bolus of 30 mg/kg followed by 5.4 mg/kg for 24 hours
Explanation
The standard practice in the pharmacologic treatment of a spinal cord injury in the United States has been the administration of methylprednisolone with an initial bolus of 30 mg/kg followed by 5.4 mg/kg for 24 hours, in accordance with the findings of the second and third National Acute Spinal Cord Injury Studies (NASCIS). Although the studies have subsequently drawn criticism for their methodology and outcomes, it has been generally accepted that beneficial neurologic outcomes were anticipated in patients who were able to start the protocol within 8 hours of their initial injury. Further improvement was noted in patients receiving the methylprednisolone within 3 hours of their injury and continuing an infusion for 48 hours. In this patient, who is outside the 8-hour treatment window, no studies have supported starting the methylprednisolone protocol at this time.
Question 2086
Topic: 6. Spine
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
Correct Answer & Explanation
. laminectomy.
Explanation
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.
Question 2087
Topic: 6. Spine
Figure 42 shows the radiograph of a patient with spinal muscular atrophy. Examination reveals good upper extremity function, and she can tie her shoes and propel a manual wheelchair. Posterior instrumentation and fusion may result in
Correct Answer & Explanation
. decreased longevity.
Explanation
DISCUSSION: Spinal muscular atrophy is caused by an abnormal survival motor neuron gene that prevents apoptosis of the motor nerves. Spinal fusion results in better sitting balance, stabilized or improved pulmonary function, and high parental satisfaction, but it may result in at least temporary loss of upper extremity function.REFERENCES: Bentley G, Haddad F, Bull TM, Seingry D: The treatment of scoliosis in muscular dystrophy using modified Luque and Harrington-Luque instrumentation. J Bone Joint Surg Br 2001;83:22-28.Furumasu J, Swank SM, Brown JC, Gilgoff I, Warath S, Zeller J: Functional activities in spinal muscular atrophy patients after spinal fusion. Spine 1989;14:771-775.Granata C, Cervellati S, Ballestrazzi A, Corbascio M, Merlini L: Spine surgery in spinal muscular atrophy: Long-term results. Neuromuscul Disord 1993;3:207-215.
Question 2088
Topic: 6. Spine
A 78-year-old woman undergoes her third lumbar decompression and fusion from L3 to L5 without complication. On the morning of postoperative day 3, examination reveals painless, flaccid weakness of both lower extremities. She also has an absent bulbocavernous reflex and a mild saddle paresthesia. MRI scans of the lumbar spine are shown in Figures 26a and 26b. What is the most appropriate management at this time?
Correct Answer & Explanation
. Continued serial neurologic examinations
Explanation
DISCUSSION: The MRI scans reveal a large postoperative hematoma causing significant thecal compression. An epidural hematoma with neurologic deficit is a surgical emergency requiring immediate evacuation of the hematoma. Although the incidence of postoperative epidural hematomas is rare, the consequences of a missed diagnosis can be catastrophic. Early recognition and evacuation are essential in preserving or restoring neurologic function. Uribe and associates attributed delayed postoperative hematomas to previous multiple lumbar surgeries as a possible contributing factor.REFERENCES: Yi S, Yoon do H, Kim KN, et al: Postoperative spinal epidural hematoma: Risk factor and clinical outcome. Yonsei Med J 2006;47:326-332.Uribe J, Moza K, Jimenez O, et al: Delayed postoperative spinal epidural hematomas. Spine J 2003;3:125-129.
Question 2089
Topic: 6. Spine
A 25-year-old man is unresponsive at the scene of a high-speed motor vehicle accident and remains obtunded. Initial evaluation in the emergency department reveals a left-sided femoral shaft fracture and a right-sided humeral shaft fracture. The cervical spine remains immobilized in a semi-rigid cervical collar, and the initial AP and lateral radiographs obtained in the emergency department are unremarkable. What is the most appropriate management at this time? Review Topic
Correct Answer & Explanation
. Lateral radiographs with passive flexion/extension views
Explanation
Clearance of the cervical spine can be difficult in the obtunded or unresponsive patient. Various trauma series have been reported to detect up to 95% of cervical fractures but only when ideal imaging views have been obtained, which is not often possible in the unresponsive or uncooperative patient. Passively performed cervical flexion-extension under live fluoroscopy has been suggested but is not without inherent risk in the potentially unstable cervical spine. CT of the cervical spine has gained acceptance for the evaluation of these patients given the excellent evaluation of the osseous anatomy and for the common availability in most emergency departments. Sanchez and associates, using a protocol to evaluate for cervical spine injuries after blunt trauma, were able to detect 99% of cervical fractures with 100% specificity.
Question 2090
Topic: 6. Spine
-Figures a and b are the MRI scans of the cervical spine without contrast of a 38-year-old man with neck pain radiating into the right upper extremity for the past 4 weeks. He denies numbness or weakness.Examination was significant for reproduction of pain going down the right arm with neck extension and right lateral rotation. What is the next treatment step?
Correct Answer & Explanation
. Physical therapy
Explanation
Question 2091
Topic: Thoracolumbar Spine & Deformity
Which of the following clinical scenarios represents an appropriate indication for convex hemiepiphysiodesis/hemiarthrodesis in the treatment of a child with a congenital spinal deformity?
Correct Answer & Explanation
. A 3-year-old child with a hemivertebra opposite a contralateral bar and thoracic scoliosis that measures 53°
Explanation
DISCUSSION: Convex hemiarthrodesis and hemiepiphysiodesis are procedures designed to gradually reduce curve magnitude in congenital scoliosis because of hemivertebrae. They are used to surgically create an anterior and posterior bar to arrest growth on the convexity of the existing deformity. Success of the technique is predicated on continued growth on the concave side of the deformity. Prerequisites for this procedure include curves of limited length (less than or equal to five vertebrae), curves of reasonable magnitude (less than 70°), absence of kyphosis, concave growth potential, and appropriate age (younger than age 5 years).REFERENCE: Winter RB, Lonstein JE, Denis F, Sta-Ana de la Rosa H: Convex growth arrest for progressive congenital scoliosis due to hemivertebrae. J Pediatr Orthop 1988;8:633-638.
Question 2092
Topic: 6. Spine
Which of the following is a true statement regarding thoracic disk herniations?
Correct Answer & Explanation
. Are most commonly discovered during the fifth to seventh decades of life
Explanation
DISCUSSION: Symptomatic herniations of the thoracic spine are much less common than those of the cervical or lumbar region. They tend to occur most commonly during the third to fifth decades of life and although they can be found at all levels, they are most common in the lower third near the thoracolumbar region. Posterior laminectomy and disk excision has the highest rate of neurologic deterioration and is not recommended. Multiple studies have shown that herniated thoracic disks can be found at one or more levels in 40% of asymptomatic individuals.REFERENCES: Shah RP, Grauer JN: Thoracoscopic excision of thoracic herniated disc, in Vaccaro AR, Bono CM (eds): Minimally Invasive Spine Surgery. New York, NY, Informa Healthcare, 2007, pp 73-80.Bohlman HH, Zdeblick TA: Anterior excision of herniated thoracic discs. J Bone Joint Surg Am 1988;70:1038-1047.
Question 2093
Topic: 6. Spine
A Trendelenburg gait is most likely to be seen in association with
Correct Answer & Explanation
. a central disk herniation at L3-L4.
Explanation
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.
Question 2094
Topic: 6. Spine
A 32-year-old woman is ejected from her vehicle in a motor vehicle accident. She has a distant history of pacemaker implantation for an unknown arrthymia. She complains of neck pain. Examination reveals midline cervical tenderness but no neurological deficit. CT scans of her cervical spine are shown in Figures A and B. She requires an emergency laparotomy for a splenic injury. Regarding her cervical spine, what is the next best step? Review Topic
Correct Answer & Explanation
. This Type I traumatic spondylolisthesis of the axis requires rigid collar immobilization.
Explanation
This patient has a Levine-Edwards Type I hangman's fracture. Rigid cervical collar immobilization is usually successful.Traditional hangman's fractures (execution by hanging) are hyperextension-distraction injuries, severing the spinal cord. Motor vehicle accidents/falls are caused by hyperextension-compression, and neurologic injury is uncommon because the fracture fragments separate, decompressing the spinal canal. The Levine-Edwards classification is most commonly used. Type II fractures have disruption of the posterior longitudinal ligament, and Type III have bilateral facet joint dislocation.Pryputniewicz et al. reviewed axis fractures. They advocate rigid collar or halo immobilization as initial treatment for hangman's fractures, and surgery for fusion failures or irreducible fractures or repeatedly unstable fractures during initial bracing. For unstable fractures or failure of external immobilization, surgical options include C2-C3 ACDF and dorsal C1-C3 fusion.Jackson et al. reviewed upper cervical spine injuries. They advocate collar immobilization for Types I and IA fractures, gentle reduction and halo vest immobilization for 6-8weeks for Types II and IIA fractures, and open reduction and wiring/plating (depending on the integrity of the facets/lamina) for Type III fractures.Li et al. performed a systematic review of hangman fractures. They advocate nonrigid external immobilization for stable Type I and Type II injuries, rigid immobilization for Type IIa and III fractures, and surgery for Levine-Edwards Type IIA and III fractures with significant dislocation or possibility for late instability.Figure A is a composite of sagittal CT scan images through left facet and pars, dens, and right facet and pars. There is no facet dislocation. Figure B is a composite of sequential axial CT scan images showing bilateral pars interarticularis fracture. Illustration A is the Effendi classification. Illustration B is the Levine-Edwards classification.Incorrect Answers:
Question 2095
Topic: 6. Spine
Figure 5 is a T2-weighted MR image of a 26-year-old man who has had left leg pain for 3 months that has failed nonsurgical treatment. Surgical decompression is planned. Which approach would provide the most direct ability to perform surgical decompression?
Correct Answer & Explanation
. Posterior midline approach
Explanation
DISCUSSIONThe MR image shows a far lateral disk herniation impinging on the exiting nerve root lateral to the exiting foramen. This is reached most directly with a far lateral (Wiltse) approach. This is a posterior paramedian approach that uses the interval between the paraspinal muscles (multifidus and longissimus) and arrives onto the facet joints. The intertransverse membrane can then be released, exposing the far lateral disk herniation. A posterior midline approach will allow easy access to the spinal canal, which is medial to the disk herniation, and will not allow for easy disk removal without the need for a facetectomy, which would destabilize the level. An anterior approach would not allow for access to the far lateral disk herniation, nor would a traditional retroperitoneal or newer transpsoas approach.RECOMMENDED READINGSWiltse LL, Spencer CW. New uses and refinements of the paraspinal approach to the lumbar spine. Spine (Phila Pa 1976). 1988 Jun;13(6):696-706. PubMed PMID: 3175760.ViewAbstract at PubMedEpstein NE. Evaluation of varied surgical approaches used in the management of 170 far-lateral lumbar disc herniations: indications and results. J Neurosurg. 1995 Oct;83(4):648-56. PubMed PMID: 7674015.View Abstract at PubMed
Question 2096
Topic: 6. Spine
A 68-year-old man reports a 4-week history of progressive left-sided lower back and hip pain. The pain is in the posterior buttock region with radiation to the groin and to the left anterior knee region. The pain is aggravated with walking and improves with rest. There is no history of previous trauma. Radiographs are seen in Figures 14a and 14b, and MRI scans are seen in Figures 14c through 14e. What is the most appropriate treatment option at this time?
Correct Answer & Explanation
. Epidural steroid injection at L4-5
Explanation
DISCUSSION: Although the imaging reveals generalized lumbar spondylosis and stenosis, in particular at L4-5, the MRI scan of the left hip clearly reveals a stress fracture of the femoral neck. Therefore, the treatment of choice is non-weight-bearing of the left lower extremity. During the evaluation of acute back pain, clinicians must include other possibilities within the differential diagnosis that may mimic mechanical axial back pain; thus, potential complications from a missed diagnosis can be avoided.REFERENCES: Wong DA, Transfeldt E: Macnab’s Backache, ed 4. Philadelphia, PA, Lippincott Williams and Wilkins, 2007, pp 339-361.Spivak JM, Connolly PJ (ed): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 43-56.
Question 2097
Topic: 6. Spine
A 3-year-old child sustains a T2/T3 fracture-dislocation with complete paraplegia secondary to a car accident in which the child was an unrestrained passenger. What is the likelihood that this child will develop subsequent spinal deformity in the future?
Correct Answer & Explanation
. 0% if bracing is used
Explanation
DISCUSSION: More than than 90% of preadolescent children who sustain a significant spinal cord injury subsequently develop scoliosis. Conversely, progressive paralytic spinal deformity is uncommon in the postadolescent patient. Bracing has not been shown to be effective in the prevention of scoliosis in the preadolescent patient with spinal cord injury.REFERENCES: Mayfield JK, Erkkila JC, Winter RB: Spine deformity subsequent to acquired childhood spinal cord injury. J Bone Joint Surg Am 1981;63:1401-1411.Dearolf WW III, Betz RR. Vogl LC, et al: Scoliosis in pediatric spinal cord-injured patients. J Pediatr Orthop 1990;10:214-218.Mehta S, Betz RR. Mulcahey MJ, et al: Effect of bracing on paralytic scoliosis secondary to spinal cord injury. J Spinal Cord Med 2004;27:S88-S92.
Question 2098
Topic: 6. Spine
Which of the following radiographic parameters is most predictive of a poor result following multilevel fusion surgery for adult degenerative scoliosis? Review Topic
Correct Answer & Explanation
. An L5-S1 degenerative disk left out of the fusion
Explanation
Sagittal imbalance appears to be the greatest predictor of a poor surgical outcome in multilevel fusions for adult scoliosis. Coronal imbalance is better tolerated as long as it is not excessive. The amount of residual scoliosis does not seem to play a role as long as overall balance is achieved. The issue of including the L5-S1 level in long fusions remains debatable, and some residual foraminal stenosis can be tolerated, particularly when included within the stabilized/fused segments.
Question 2099
Topic: Cervical Spine
A previously healthy 35-year-old man was involved in a rollover motor vehicle accident 2 days ago. He was placed in a semi-rigid cervical orthosis. He now reports mostly axial neck pain with attempted range of motion. Examination reveals the mechanical neck pain but no obvious neurologic deficits. AP, flexion, and extension radiographs are shown in Figures 10a through 10c, and sagittal and coronal CT scans are shown in Figures 10d and 10e. What is the most appropriate management at this time?
Correct Answer & Explanation
. Continued immobilization in a semi-rigid cervical orthosis for 6 to 8 weeks
Explanation
DISCUSSION: Odontoid fractures can be classified based on the anatomic position of the fracture within the dens itself. Type I is an oblique fracture through the upper part of the odontoid process. Type II is a fracture that occurs at the base of the odontoid as it attaches to the body of C2; type III occurs when the fracture line extends through the body of the axis. Type 1 fractures typically can be treated nonsurgically with 6 to 8 weeks of immobilization with a semi-rigid cervical orthosis. Nondisplaced, deep type III fractures generally are treated with skeletal halo fixation. Deep, displaced, and angled type III fractures can be treated with closed reduction and skeletal halo fixation. Shallow type III fractures are sometimes amenable to anterior odontoid screw fixation. Type II fractures can be managed nonsurgically or surgically. Treatment options include halo immobilization, internal fixation (odontoid screw fixation), and posterior atlantoaxial arthrodesis. Management with the halo vest usually is considered if the initial dens displacement is less than 6 mm, the reduction is performed within 1 week of the injury and is able to be maintained, and the patient is younger than age 60 years. Halo vest immobilization can lead to a healing rate of more than 90%. Posterior surgical fusion techniques provide high fusion success rates but do so at the expense of cervical rotation. Up to 50% of rotation is lost with these techniques. Anterior odontoid single screw fixation is often tolerated better than skeletal halo fixation and also is noted to preserve the normal rotation at C1/C2. Studies have shown less of a malunion and nonunion rate in the treatment of type II odontoid fractures with anterior odontoid screw fixation. Osteoporosis, short neck and barrel-chested anatomy, and fractures that are more than 4 weeks old preclude anterior odontoid fixation.REFERENCES: Shilpakar S, McLaughlin MR, Haid RW Jr, et al: Management of acute odontoid fractures: Operative techniques and complication avoidance. Neurosurg Focus 2000;8:e3.Subach BR, Morone MA, Haid RW Jr, et al: Management of acute odontoid fractures with single-screw anterior fixation. Neurosurgery 1999;45:812-819.Fountas KN, Kapsalaki EZ, Karampelas I, et al: Results of long-term follow-up in patients undergoing anterior screw fixation for type II and rostral type III odontoid fractures. Spine 2005;30:661-669.
Question 2100
Topic: 6. Spine
A collegiate lacrosse player is struck on the head by an opposing player’s stick. She is initially unresponsive. She regains consciousness within 2 minutes but remains confused and uncooperative, complaining of head and neck pain. This is her second concussion of the calendar year. Initial management should consist of
Correct Answer & Explanation
. calculation of Glasgow Coma Scale score.
Explanation
This patient has sustained a significant concussion or minor brain injury. Although all answer options reflect important steps in her management, the initial primary concern in any player who is confused or combative is protection of the cervical spine until formal clearance can be performed. This patient requires immediate immobilization, collar placement, and, ultimately, transportation to a hospital. Cervical immobilization should be achieved before transport, given her complaints of neck pain and inability to provide a reliable examination.
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