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6. Spine MCQs

Practice Set 148 of 379

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 2941

Topic: 6. Spine

Figures 21a and 21b show the radiographs of a 12-year-old patient with an L4-level myelomeningocele who has scoliosis that has been slowly progressing for the past several years. There has been no loss of motor function. An MRI scan shows no syringomyelia or increased hydrocephalus. Management should consist of

. follow-up with repeat radiographs in 6 months.
. brace treatment.
. posterior spinal fusion with instrumentation.
. anterior and posterior spinal fusion with instrumentation.
. anterior spinal fusion with instrumentation.

Correct Answer & Explanation

. anterior and posterior spinal fusion with instrumentation.

Explanation

Scoliosis is a common occurrence in children with myelomeningocele, with the incidence increasing as the neurologic level moves cephalad. The rate of pseudarthrosis for isolated anterior or posterior fusions has been reported as high as 75%. The combination of anterior and posterior fusions with some type of instrumentation has been shown to decrease the rate of pseudarthrosis to 20%. Brace treatment in smaller curves can be used as a temporizing measure to delay surgery, but as with idiopathic scoliosis, the brace is ineffective for larger curves. Observation is not indicated with a curve of this magnitude. Ward WT, Wenger DR, Roach JW: Surgical correction of myelomeningocele scoliosis: A critical appraisal of various spinal instrumentation systems. J Pediatr Orthop 1989;9:262-268.

Question 2942

Topic: 6. Spine

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?

Spine Surgery 2006 Practice Questions: Set 1 (Solved) - Figure 20

. Multilevel anterior cervical diskectomy with fusion
. Anterior and posterior decompression with fusion
. Anterior corpectomy and fusion with a fibula strut
. Laminectomy and bilateral foraminotomies
. Laminectomy and posterior fusion with lateral mass plating

Correct Answer & Explanation

. Anterior corpectomy and fusion with a fibula strut

Explanation

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. 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.

Question 2943

Topic: 6. Spine

A 32-year-old man sustained an L1 burst fracture with 90% canal compromise, intact posterior elements, and kyphosis of 25% at the L1 level. He has an incomplete neurologic injury. Definitive management should consist of

Trauma 2000 Practice Questions: Set 1 (Solved) - Figure 22

. bed rest for 8 weeks, followed by mobilization in a total contact thoracolumbosacral orthosis.
. immediate laminectomy only.
. anterior decompression, vertebral body reconstruction, and stabilization.
. in situ posterior fusion.
. short segment posterior fixation and fusion.

Correct Answer & Explanation

. anterior decompression, vertebral body reconstruction, and stabilization.

Explanation

With an incomplete injury, the best chance for recovery occurs when the canal is cleared and the neural structures are decompressed. Anterior decompression, vertebral body reconstruction, and anterior stabilization have been shown to be highly effective in the treatment of burst-type injuries. Laminectomy alone is contraindicated because it increases the instability. Short segment posterior fixation has a high rate of failure in this type of injury at this level. Kaneda K, Abumi K: Burst fractures with neurologic deficits of the thoracolumbar spine. J Bone Joint Surg Am 1997;79:69-83.

Question 2944

Topic: 6. Spine
A 12-year-old girl has had lower back pain for the past 6 months that interferes with her ability to participate in sports. She denies any history of radicular symptoms, sensory changes, or bowel or bladder dysfunction. Examination reveals a shuffling gait, restriction of forward bending, and tight hamstrings. Radiographs show a grade III spondylolisthesis of L5 on S1, with a slip angle of 20 degrees. Management should consist of
. brace treatment.
. laminectomy, nerve root decompression, and in situ fusion of L4 to the sacrum.
. in situ fusion of L4 to the sacrum.
. excision of the L5 lamina.
. physical therapy.

Correct Answer & Explanation

. laminectomy, nerve root decompression, and in situ fusion of L4 to the sacrum.

Explanation

Indications for surgical treatment of spondylolisthesis include pain and/or progression of deformity. Specifically, surgery is necessary when there is persistent pain or a neurologic deficit that fails to respond to nonsurgical therapy, there is significant slip progression, or the slip is greater than 50%. For patients with mild spondylolisthesis, in situ posterolateral L5-S1 fusion is adequate. In patients with more severe slips (greater than 50%), extension of the fusion to L4 offers better mechanical advantage. Postoperative immobilization may be achieved with instrumentation, casting, or both. In patients with a slip angle of greater than 45 degrees, reduction of the lumbosacral kyphosis with instrumentation or casting is desirable to prevent slip progression. Laminectomy alone is contraindicated in a child. Nerve root decompression is indicated if radiculopathy is present clinically.

Question 2945

Topic: 6. Spine

Figures 19a through 19c show radiographs of the cervical spine of an asymptomatic patient with Down syndrome who wants to participate in a Special Olympics running event. The neurologic examination is normal. Management should consist of

. an MRI scan.
. fusion from the occiput to C2.
. fusion of C1-C2.
. application of a cervical collar and no participation in any sports.
. periodic follow-up examinations and no contact sports.

Correct Answer & Explanation

. periodic follow-up examinations and no contact sports.

Explanation

An atlanto-dens interval (ADI) of up to 4 mm in children is considered normal. Children with Down syndrome have increased ligamentous laxity, with atlantoaxial instability occurring in as many as 15% to 20% of patients. These patients are at risk for catastrophic injury following minor trauma and should be routinely screened for instability, generally beginning when the patient starts to walk. Patients with an ADI of greater than 5 mm should avoid contact sports and high-risk activities such as gymnastics, diving, the high jump, and the butterfly stroke. The American Academy of Pediatrics Committee of Sports Medicine and Fitness guidelines recommend that lateral views of the cervical spine in neutral, flexion, and extension should be obtained in all children with Down syndrome who wish to participate in sports. Patients with normal radiographs and examinations do not need repeat radiographs, although some authors suggest that instability increases with age, and therefore recommend repeat radiographs every 5 years. Cervical spine fusion in patients with Down syndrome has a high rate of complications and should be performed only on patients with symptoms and evidence of myelopathy. American Academy of Pediatrics Committee of Sports Medicine and Fitness: Atlantoaxial instability in Down syndrome. Pediatrics 1995;96:151-154. Copley LA, Dormans JP: Cervical spine disorders in infants and children. J Am Acad Orthop Surg 1998;6:204-214.

Question 2946

Topic: 6. Spine

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

Spine Surgery 2006 Practice Questions: Set 1 (Solved) - Figure 3

. no antibiotics.
. oral broad-spectrum antibiotics for 7 days.
. intravenous broad-spectrum antibiotics for 48 hours.
. intravenous broad-spectrum antibiotics for 7 days.
. intravenous antibiotics specific for Staphylococcus for 7 days.

Correct Answer & Explanation

. intravenous broad-spectrum antibiotics for 7 days.

Explanation

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

Question 2947

Topic: 6. Spine

A 45-year-old man undergoes an anterior cervical diskectomy and fusion at C5-6 and C6-7 with instrumentation. During the first postoperative visit at 1 week, the patient reports difficulty swallowing and mild anterior cervical tightness. The anterior wound is benign and the patient denies any dyspnea or shortness of breath. A postoperative radiograph is seen in Figure 25. What is the most appropriate management at this time?

Spine Surgery 2009 Practice Questions: Set 3 (Solved) - Figure 12

. Admit for observation and reassurance
. Surgical exploration and removal of the anterior instrumentation
. Esophageal swallowing study
. Soft cervical collar and early range-of-motion exercises
. CT of the cervical spine

Correct Answer & Explanation

. Admit for observation and reassurance

Explanation

The radiograph shows significant prevertebral soft-tissue swelling following a two-level anterior cervical diskectomy and fusion. The incidence of dysphagia 2 years after anterior cervical spine surgery is 13.6%. Risk factors for long-term dysphagia after anterior cervical spine surgery include gender, revision surgeries, and multilevel surgeries. The use of instrumentation, higher levels, or corpectomy versus diskectomy did not significantly increase the prevalence of dysphagia. Lee and associates demonstrated that while dysphagia after anterior cervical spine surgery is a common early finding, it generally decreases significantly by 6 months with nonsurgical management. A minority of patients experience moderate or severe symptoms by 6 months after the procedure. Female gender and multiple surgical levels have been identified as risk factors for the development of postoperative dysphagia. Lee MJ, Bazaz R, Furey CG, et al: Risk factors for dysphagia after anterior cervical spine surgery: A two-year prospective cohort study. Spine J 2007;7:141-147.

Question 2948

Topic: Thoracolumbar Spine & Deformity

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?

. Anterior pseudarthrosis
. Prior laminectomy at the osteotomy level
. Sagittal decompensation of more than 20 cm on standing lateral radiographs
. Kyphosis at the thoracolumbar junction
. Vascular calcification at the osteotomy site

Correct Answer & Explanation

. Anterior pseudarthrosis

Explanation

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

Question 2949

Topic: 6. Spine

A 35-year-old man sustained a 10% compression fracture of the C5 vertebra in a diving accident. Radiographs show good alignment, and examination reveals no neurologic compromise. An MRI scan reveals no significant soft-tissue disruption posteriorly. Management should consist of

. observation.
. a rigid collar for 6 weeks.
. halo vest application.
. open reduction and posterior stabilization.
. open reduction, diskectomy, grafting, and anterior plate stabilization.

Correct Answer & Explanation

. a rigid collar for 6 weeks.

Explanation

The patient has a stable flexion-compression injury of the cervical spine. The fracture occurs as a result of compression failure of the vertebral body. If the force continues, a tension failure of the posterior structures occurs, leading to potential dislocation. Immobilization in a rigid cervical orthosis will allow this fracture to heal. Clark CR (ed): The Cervical Spine, ed 3. Philadelphia, PA, Lippincott-Raven, 1998, pp 457-464.

Question 2950

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?

Spine Surgery 2000 Practice Questions: Set 3 (Solved) - Figure 11

. Nonsteroidal anti-inflammatory drugs and reassurance that this is a steroid flare reaction that should subside within 2 to 3 days
. Emergent L4-5 diskectomy
. Repeat epidural steroid injection at L4-5 under fluoroscopy
. MRI of the lumbar spine
. Myelography and CT

Correct Answer & Explanation

. MRI of the lumbar spine

Explanation

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

Question 2951

Topic: Cervical Spine

A 51-year-old woman with no preoperative neurologic deficit is undergoing elective anterior cervical diskectomy and fusion (ACDF) with plating and fusion for a C5-6 disk herniation with right-sided neck pain. Thirty minutes into the surgery the neurophysiologic monitoring shows a rapid drop and then loss of amplitude in the right cortical somatosensory-evoked potential waveform. All other waveforms remained normal and unchanged, including right-sided cervical (subcortical) and peripheral (Erb's point), and those from the left-sided upper extremity and both lower extremities. What is the most likely cause of the change?

Spine Surgery 2009 Practice Questions: Set 1 (Solved) - Figure 25

. Electrode placement
. Stimulation failure
. Anesthetic effect
. Cord ischemia from retraction
. Cerebral ischemia from retraction

Correct Answer & Explanation

. Cerebral ischemia from retraction

Explanation

The change noted is focal and confined to the cortex, sparing the opposite side, both lower extremities, and the subcortical waveforms, making all the choices unlikely with the exception of carotid compression with focal cortical ischemia. This may be associated with poor collateral flow from the opposite hemisphere due to an incomplete circle of Willis. Drummond JC, Englander RN, Gallo CJ: Cerebral ischemia as an apparent complication of anterior cervical discectomy in a patient with an incomplete circle of Willis. Anesth Analg 2006;102:896-899.

Question 2952

Topic: 6. Spine

Posterior spinal fusion for scoliosis should be performed on a patient with Duchenne muscular dystrophy when

. the patient is still ambulatory.
. lordotic posture is present.
. the forced vital capacity (FVC) is less than 30% of the predicted value.
. curve magnitude measures 25 degrees or greater.
. orthotic management fails.

Correct Answer & Explanation

. curve magnitude measures 25 degrees or greater.

Explanation

Progressive scoliosis develops in most patients with Duchenne muscular dystrophy. The onset of spinal deformity typically follows the cessation of walking, and curves can be expected to progress about 10 degrees per year. Posterior spinal fusion with instrumentation should be performed as soon as a curve of 25 degrees or greater is documented and before deterioration of pulmonary function (a FVC of less than 30%) precludes surgery. Patients with kyphotic posture tend to progress more rapidly than those with lordotic posture. Brace treatment is contraindicated because it is not definitive and it may mask curve progression while pulmonary function is concomitantly worsening. Beaty JH (ed): Orthopaedic Knowledge Update 6. Rosemont, Ill, American Academy of Orthopaedic Surgeons, 1999, pp 635-651.

Question 2953

Topic: 6. Spine

A 44-year-old man reports persistent left leg pain following a L5-S1 hemilaminotomy and partial diskectomy. Examination shows a grade 4 weakness of the left extensor hallucis longus and a positive left straight leg raise. A radiograph is shown in Figure 1a, and sagittal and axial MRI scans are shown in Figures 1b and 1c. Nonsurgical management consisting of medication, physical therapy, and injections has failed to provide relief. Surgical management should consist of

. revision L5-S1 hemilaminotomy.
. L5-S1 total disk arthroplasty.
. L5 Gill laminectomy.
. posterior foraminal decompression and fusion at L5-S1 with instrumentation and bone graft.
. stand-alone posterior lumbar interbody fusion.

Correct Answer & Explanation

. posterior foraminal decompression and fusion at L5-S1 with instrumentation and bone graft.

Explanation

The patient has a grade I isthmic spondylolisthesis at L5-S1. He has an L5 radiculopathy with foraminal stenosis. Any further treatment needs to include an arthrodesis and foraminal decompression. Isolated interbody fusion is contraindicated in patients with spondylolisthesis, as is total disk arthroplasty. Therefore, the best procedure is a posterior fusion with instrumentation and bone graft along with a foraminal decompression. Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 311-317.

Question 2954

Topic: 6. Spine

A 55-year-old man reports increasing weakness in his arms that has progressed to his lower limbs, resulting in frequent tripping and falling. Examination reveals weakness in shoulder abduction and external and internal rotation bilaterally. Fasciculation is noted. He also has weakness in elbow flexion and extension bilaterally, and his grip strength is diminished. An electromyogram and nerve conduction velocity studies show decreased amplitude of compound motor action potential, slightly slowed motor conduction velocity, and denervation signs with decreased recruitment in all extremities. The sensory study is normal. Based on these findings, what is the most likely diagnosis?

Upper Extremity Board Review 2005: High-Yield MCQs (Set 2) - Figure 27

. Syrinx of the cervical spine
. Intracranial mass
. Myasthenia gravis
. Amyotrophic lateral sclerosis (ALS)
. Fascioscapulohumeral dystrophy

Correct Answer & Explanation

. Amyotrophic lateral sclerosis (ALS)

Explanation

The major determinant of ALS (Lou Gehrig disease) is progressive loss of motor neurons. The loss usually begins in one area, is asymmetrical, and later becomes evident in other areas. The first signs of ALS may include either upper or lower motor neuron loss. Recognition of upper motor neuron involvement depends on clinical signs, but electromyography and nerve conduction velocity studies can help identify lower motor neuron involvement. Electrodiagnostic abnormalities in three or more areas are required to make a definitive diagnosis. The motor unit potentials (MUPs) changes in ALS include impaired MUPs recruitment, unstable MUPs, and abnormal MUPs size and configuration. A number of abnormal spontaneous discharges can occur with ALS, especially fibrillation potentials and fasciculation potentials. In ALS, the motor nerve conduction study will be abnormal, but a co-existing normal sensory study is definitive for this disease. de Carvalho M, Johnsen B, Fuglsang-Frederiksen A: Medical technology assessment: Electrodiagnosis in motor neuron diseases and amyotrophic lateral sclerosis. Neurophysiol Clin 2001;31:341-348. Daube JR: Electrodiagnostic studies in amyotrophic lateral sclerosis and other motor neuron disorders. Muscle Nerve 2000;23:1488-1502.

Question 2955

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

. laminectomy.
. hemilaminectomy.
. laminectomy and posterolateral fusion.
. anterior interbody fusion.
. posterolateral fusion.

Correct Answer & Explanation

. laminectomy and posterolateral fusion.

Explanation

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. 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.

Question 2956

Topic: Thoracolumbar Spine & Deformity

Figure 45 shows the lateral radiograph of a 19-year-old swimmer who has had back pain for the past 2 months. What is the most likely diagnosis?

Anatomy Board Review 2002: High-Yield MCQs (Set 4) - Figure 7

. Disk degeneration
. Limbus fracture
. Degenerative retrolisthesis of L4-5
. Spondylolysis
. Osteoid osteoma

Correct Answer & Explanation

. Spondylolysis

Explanation

The patient has a pars interarticularis defect of L5 without apparent listhesis. The other diagnoses are not present. Papanicolaou N, Wilkinson RH, Emmans JB, Treves S, Micheli LJ: Bone scintigraphy and radiography in young athletes with low back pain. Am J Roentgenol 1985;145:1039-1044.

Question 2957

Topic: 6. Spine

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?

. Referral to the pain clinic to consider insertion of a morphine pump
. L1-2 laminectomy
. L1-2 anterior lumbar interbody fusion via a minimally invasive technique
. Posterior laminectomy and uninstrumented fusion
. Posterior decompression and instrumented fusion

Correct Answer & Explanation

. Posterior decompression and instrumented fusion

Explanation

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.

Question 2958

Topic: 6. Spine

A 22-year-old woman injures her neck in a motor vehicle accident. Examination reveals no sensory or motor function below T8. Radiographs and an MRI scan show a burst fracture at T7. Forty-eight hours later, the bulbocavernosus reflex is present but there is no evidence of motor or sensory recovery in the lower extremities. What is the most likely diagnosis?

Trauma 2009 Practice Questions: Set 1 (Solved) - Figure 25

. Spinal shock
. Anterior cord syndrome
. Cauda equina syndrome
. Complete cord syndrome
. Brown-Sequard syndrome

Correct Answer & Explanation

. Complete cord syndrome

Explanation

Spinal shock typically ends after 48 hours with the return of reflexes, including the bulbocavernosus reflex. Lack of motor or sensory recovery in the lower extremities with the return of reflexes generally indicates a complete cord syndrome. Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 179-187.

Question 2959

Topic: 6. Spine

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

Spine Surgery 2000 Practice Questions: Set 1 (Solved) - Figure 20

. Spastic gait and a positive Hoffman's sign
. Severe arm pain with upper extremity hyporeflexia
. Normal neurologic findings
. Hyperactive jaw jerk reflex with extremity numbness
. Flaccid paraparesis

Correct Answer & Explanation

. Spastic gait and a positive Hoffman's sign

Explanation

Cervical myelopathy involves compression of the spinal cord and presents as an upper motor neuron disorder. Patients commonly have extremity spasticity and problems with ambulation and balance. Hoffman's sign is often present and is elicited by suddenly extending the distal interphalangeal joint of the middle finger; reflexive finger flexion represents a positive finding. The extremities are usually hyperreflexic with myelopathy. With cervical radiculopathy (lower motor neuron disorder), reflexes are hyporeflexic, and patients report pain along a dermatomal distribution. A hyperactive jaw jerk reflex indicates pathology above the foramen magnum or in some cases, systemic disease. Flaccid paraparesis suggests a lower motor neuron problem. Sachs BL: Differential diagnosis of neck pain, arm pain and myelopathy, in Clark CR (ed): The Cervical Spine, ed 3. Philadelphia, PA, Lippincott Raven, 1998, pp 741-742.

Question 2960

Topic: 6. Spine

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

. CT-guided needle aspiration and organism-appropriate antibiotics.
. laminectomy and postoperative bracing.
. posterior fusion with instrumentation and IV antibiotics.
. anterior debridement and strut graft, with possible posterior instrumentation.
. posterior extracavitary decompression alone.

Correct Answer & Explanation

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

Explanation

Indications for surgery in spinal infections include progressive destruction despite antibiotic treatment, an abscess requiring drainage, neurologic deficit, need for diagnosis, and/or instability. This patient has a progressive neurologic deficit. Debridement performed at the site of the abscess should effect canal decompression. Once the debridement is complete back to viable bone, the defect can be reconstructed with a strut graft. Additional posterior stabilization is used as deemed necessary by the degree of anterior destruction. CT-guided needle aspiration, while occasionally useful in the earliest phases of an infection, produces frequent false-negative results and would provide little useful information in the management of this patient. Emery SE, Chan DP, Woodward HR: Treatment of hematogenous pyogenic vertebral osteomyelitis with anterior debridement and primary bone grafting. Spine 1989;14:284-291. Lifeso RM: Pyogenic spinal sepsis in adults. Spine 1990;15:1265-1271.

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