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 2301
Topic: 6. Spine
What is the most common non-anesthetic-related reversible cause of sustained changes in intraoperative neurophysiologic monitoring signals during spinal surgery? Review Topic
Correct Answer & Explanation
. Pedicle screw misplacement
Explanation
Patient positioning that results in local nerve compression, plexus traction, or improper neck alignment is the most common non-anesthetic-related cause of changes in intraoperative neurophysiologic monitoring data during spinal surgery. Pedicle screw malpositioning, spinal cord ischemia, and retractor placement are all less common causes. Hypotension, not hypertension, can be a cause of intraoperative neurophysiologic changes.
Question 2302
Topic: 6. Spine
A comparison of dural tears repaired with suture alone and those treated by suture with fibrin glue supplementation will reveal which of the following findings?
Correct Answer & Explanation
. A more marked inflammatory response with fibrin glue supplementation
Explanation
Animal studies assessing the influence of fibrin glue supplementation have detected a markedly greater inflammatory response at the site of application. An increased incidence of infection and delays in healing were not noted.
Question 2303
Topic: 6. Spine
A 14-year-old boy has failed physical therapy management for Scheuermann kyphosis, and an extension thoracolumbosacral orthosis brace is recommended. The boy and his parents are told that the brace will force his thoracic spine into normal sagittal alignment and put the anterior vertebral bodies of the thoracic segment into tension, which will induce bone growth and normalization of wedge-shaped vertebrae. What name is associated with this process?
Correct Answer & Explanation
. Hooke's law
Explanation
The Heuter-Volkmann principle shows that bone placed in longitudinal tension will tend to stimulate longitudinal growth, and that compressive longitudinal forces inhibit longitudinal growth, making this response the best choice. Hooke's law relates to stress being proportional to strain and is not directly related to bone growth. Kirchhoff's laws apply to electrical circuit design. Wolff's law states that boneremodels in response to mechanical stress, with the correlate that increased stress causes increased growth, and decreased stress leads to bone loss.
Question 2304
Topic: 6. Spine
The illustration shown in Figure 19 shows a Chamberlain line. What is the most likely diagnosis?
Correct Answer & Explanation
. Basilar invagination
Explanation
Basilar invagination is best defined as vertical or compressive instability at the occiput-C1 joint. Such invaginations most commonly occur in patients with rheumatoid arthritis but also can occur secondary to trauma or tumor. A Chamberlain line is used as a method to determine basilar invagination. The odontoid tip should not be more than 5 mm above a Chamberlain line.
Question 2305
Topic: 6. Spine
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
Correct Answer & Explanation
. MRI.
Explanation
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.
Question 2306
Topic: 6. Spine
A 29-year-old man reports a 2-week history of severe neck pain after being struck sharply on the back of the head and neck while moving a refrigerator down a flight of stairs. Initial evaluation in the emergency department revealed no obvious fracture and he was discharged in a soft collar. Neurologic examination is within normal limits, and radiographs taken in the office are shown in Figures 21a through 21c. Subsequent MRI scans show intra-substance rupture of the transverse atlantal ligament. What is the most appropriate treatment option at this time? Review Topic
Correct Answer & Explanation
. Discontinue use of the soft collar and encourage range of motion
Explanation
Dickman and associates classified injuries of the transverse atlantal ligament into two categories. Type I injuries are disruptions through the substance of the ligament itself. Type II injuries render the transverse ligament physiologically incompetent through fractures and avulsions involving the tubercle of insertion of the transverse ligament on the C1 lateral mass. Type I injuries are incapable of healing without supplemental internal fixation. Type II injuries can be treated with a rigid cervical orthosis with a success rate of 74%. Surgery may be required for type II injures that fail to heal with 3 to 4 months of nonsurgical management.(SBQ13PE.82) A renal ultrasound should be obtained in a patient with which of the following diagnoses?Review TopicCongenital pseudoarthrosis of the clavicleAccessory navicularCongenital scoliosisCharcot-Marie-Tooth DiseaseCongenital curly toeA renal ultrasound should be obtained in a patient with congenital scoliosis.Congenitial scoliosis has a prevalence that is estimated at 1% to 4% in general population. It is associated with systemic anomalies in up to 61% of cases. The most common anomalies are cardiac defects, genitourinary defects and spinal cord malformations. As such, additional imaging of these systems should be considered in the initial work-up of these patients.Ruf et al. retrospectively investigated 56 consecutive operative cases of congenital scoliosis. The average age at surgery was 9.9 years (1.5–17 years). There was one wound complication, 2 hardware failures, 1 revision and no neurological complications. They concluded that one-stage posterior hemivertebra resection and instrumentation was safe in this population.Xu et al. examined the efficacy of selective partial hemivertebra excision via posterior-only approach in 17 adolescent patients with congenital kyphoscoliosis. There were no postoperative infections and no neurological complications. They concluded that this approach may be most successful in patients aged 9 to 14 years old, with the Risser sign grades from 0–3 and Cobb angles <60°.Illustration A from Erol et al (UPOJ, Vol 15, 2002;37-42) shows a diagram of 'types' of congenital scoliosis based on the morphology of the vertebrae.Incorrect Answers:
Question 2307
Topic: 6. Spine
A patient has a large T11-T12 disk herniation that is causing substantial compression of the spinal cord. The patient reports walking imbalance over the past few weeks. Examination of the patient's reflexes is likely to show Review Topic
Correct Answer & Explanation
. normal reflexes in the upper extremities and hyperreflexia in the lower extremities.
Explanation
The patient has a large thoracic disk herniation that is causing spinal cord compression. The history of gait imbalance suggests that the patient has thoracic level myelopathy. Assuming that the patient does not have lumbar stenosis, compression of the spinal cord at the T11-T12 level will cause upper motor neuron findings distal to it. Hyperreflexia of the upper extremities would suggest that the patient has cervical spinal cord compression. In this patient, the upper extremity reflexes should be normal. Most likely, the patient will exhibit hyperreflexia in the lower extremities, which is an upper motor tract sign.
Question 2308
Topic: 6. Spine
A 28-year-old man has had a 2-week history of right posterior leg pain, with numbness and tingling in the same distribution. He denies any problems with bowel or bladder function. Examination shows intact motor strength in his bilateral lower extremities, with numbness to light touch in the lateral border of his right foot. Over the past 2 weeks, his leg pain has improved significantly. MRI scans are shown in Figures 57a and 57b. What is the most appropriate course of management?
Correct Answer & Explanation
. Activity modification and anti-inflammatory medications
Explanation
The patient has an L5-S1 disk herniation, which has a favorable prognosis without surgical intervention. Most acute lumbar disk herniations resolve with nonsurgical management. The most appropriate course of initial treatment should be analgesics and activity modification, followed by rehabilitation as the symptoms allow. Although the MRI scan indicates a large disk herniation, he has no symptoms or signs that would warrant urgent surgical decompression. Planned elective diskectomy should be considered only if nonsurgical management fails to provide relief. Epidural injections could be considered if the initial course of treatment fails to give the patient significant relief. Posterior laminectomy and fusion is not indicated without the presence of instability.
Question 2309
Topic: 6. Spine
What clinical scenario is most consistent with the MR image of the L4-L5 disk level shown in Figure 14? Review Topic
Correct Answer & Explanation
. Left L4 nerve root radiculopathy
Explanation
The MRI scan reveals a foraminal disk herniation originating from the L4-L5 disk space that has migrated into the foramen compressing the left L4 nerve root. There is no evidence of compression of the right L5 nerve root. Bowel and bladder dysfunction are not associated with L4-mediated nerve function. There is no evidence of arachnoiditis or pseudomeningocele.
Question 2310
Topic: 6. Spine
A 68-year-old male presents with gait instability, clumsiness of the hands, and the MRI images shown in Figure A. You decide to proceed with surgical decompression. When planning your surgical treatment, it is important to note that compared to a posterior approach, the anterior procedure has: Review Topic
Correct Answer & Explanation
. Higher risk of infection
Explanation
Surgical decompression of cervical myelopathy via an anterior procedure has lower reported blood loss compared to a posterior procedure.Cervical myelopathy has a progressive course and therefore if there is evidence of functional impairment surgical decompression is indicated. Either an anterior decompression or posterior decompression can be used depending on a variety of factors including number of levels involved and sagittal alignment of the cervical spine. In general, a posterior approach is used when three or more levels are involved and the spine is in neutral or lordotic alignment.Fehlings et al. did a prospective study on the risks of complications associated with surgical treatment of cervical myelopathy. They found that combined anterior and posterior procedures had a significantly higher rate of complication than either anterior-only or posterior-only procedures. Posterior procedures had a higher rate of wound infections compared to anterior. They found no statistical difference in the over-all complication rate, incidence of C5 radiculopathy, or dysphagia between an anterior-only or posterior-only procedure.Fehlings et al. did a prospective study on outcomes following surgical treatment of cervical myelopathy. At one year follow-up they found a significant improvement in mJOA score, Nurick grade, NDI score, and all SF-36v2 dimensions. With the exception of mJOA scores, these improvements were not statistically related to severity of disease.Liu et al. performed a meta-analysis of outcomes following surgical decompression of cervical myelopathy. They found outcomes following anterior procedures were better than those for posterior procedures when there were less than 3 affected levels. With 3 or greater levels, no statistical difference in outcomes could be found between the two approaches. They note none of their reviewed publications represent high-quality prospective randomized trials.Figure A is a sagittal MR image of the cervical spine showing multi-level degenerative disease with cord compression consistent with cervical myelopathy.Incorrect Answers:
Question 2311
Topic: 6. Spine
Which of the following is the strongest contraindication for expansive open door laminoplasty for cervical myelopathy? Review Topic
Correct Answer & Explanation
. Multi-level cervical spondylosis
Explanation
Expansive open door laminoplasty is a method of posterior cervical decompression. It is contra-indicated for patients with cervical kyphosis unless the surgical plan includes concomitant correction of deformity.Open door laminoplasty allows decompression direct posterior decompression of the neural elements, as well as an indirect anterior decompression by allowing the cord to drift posteriorly. Posterior drift of the cord relies upon the presence of natural cervical lordosis. In the setting of kyphosis, the cord is tensioned ventrally over the vertebral bodies and discs, and does not have the redundancy to drift backward. Patients without lordosis would therefore be expected to show less post-operative improvement than those with normal cervical curvature.Chiba et al. performed a retrospective review of patients treated with expansive open door laminoplasty for cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament (OPLL). They found that for patients with OPLL, cervical kyphosis was associated with lower recovery rates than those patients with pre-operative lordosis. The authors recommended against posterior decompression for CSM in the setting of OPLL with concomitant cervical kyphosis.Suda et al. performed a retrospective review of 114 patients who underwent expansiveopen door laminoplasty for cervical myelopathy in order to evaluate clinical outcomes and effects on cervical alignment. They found patients with C2-C7 kyphosis >13° had much lower rates of improvement compared with those patients with less kyphosis. The authors suggest an anterior decompression be used for patients with kyphosis greater than 13°, unless kyphotic correction was planned in addition to a laminoplasty.Illustrations:Illustration A demonstrates a lateral cervical spine x-ray which shows focal kyphosis at C4-5 and C5-6. Illustration B demonstrates the C7-sagittal vertical axis. Illustration C demonstrates the compression ratio.Incorrect<0.4 implies a poor prognosis.
Question 2312
Topic: 6. Spine
A 65-year-old woman undergoes a lumbar laminectomy for spinal stenosis at the L3-L4 level. The surgery and postsurgical course are uncomplicated. Eight weeks after surgery she has severe left anterior thigh, groin, and knee pain with ambulation and standing. Which condition is the most likely cause of her symptoms?
Correct Answer & Explanation
. Osteoarthritis of the hip
Explanation
Disorders of the hip can mimic and/or coexist with lumbar spine disorders. Osteoarthritis of the hip typically causes groin and anterior thigh pain. Meralgia paraesthetica is more likely to manifest immediately after surgery. Facet joint pain causes low-back pain that can be referred to the gluteal region. Epidural hematoma 6 weeks after surgery is highly unlikely.
Question 2313
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?
Correct Answer & Explanation
. Complete cord syndrome
Explanation
DISCUSSION: 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. REFERENCES: Spivak JM, Connolly PJ (eds): Orthopaedic Knowledge Update: Spine 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2006, pp 179-187. Herkowitz HN, Garfin SR, Eismont FJ: Rothman-Simone The Spine, ed 5. Philadelphia, PA, Saunders Elsevier, 2006, pp 1132-1133.
Question 2314
Topic: 6. Spine
A 12-year-old girl who is Risser stage 3 has had intermittent mild midback pain for the past 4 weeks. The pain is worse after prolonged sitting and after carrying a heavy backpack at school. She occasionally takes acetaminophen, but the pain does not limit sport activities. Examination reveals a mild right rib prominence during forward bending. Neurologic examination is normal. Radiographs show a 20-degree right thoracic scoliosis with no congenital anomalies or lytic lesions. Management should consist of Review Topic
Correct Answer & Explanation
. back muscle stretching and reduced weight in the backpack.
Explanation
Mild scoliosis is not a painful condition, but it usually presents during adolescence. Intermittent back pain is reported by 25% to 30% of adolescents whether or not scoliosis is present. Such pain is often attributed to muscle strain from tight muscles, poor posture, or heavy school backpacks. The clinician must distinguish typical pain (mild, intermittent, nonlimiting) from atypical pain. The latter requires more careful examination and imaging studies (bone scan or MRI) to determine the source of pain. The patient’s age and right thoracic curve pattern are typical for idiopathic scoliosis; therefore, imaging of the neuroaxis is not necessary to look for cord syrinx, tethering,or tumor. Brace treatment is not required for this small curve unless future progression is demonstrated.
Question 2315
Topic: 6. Spine
A 29-year-old man undergoes surgery for a grade I isthmic spondylolisthesis at L5. Following surgery, what type of brace will best immobilize the L5-S1 motion segment?
Correct Answer & Explanation
. Thoracolumbosacral orthosis with thigh extension
Explanation
The thoracolumbosacral orthosis with thigh extension best immobilizes the lumbosacral junction. Fidler and Plasmans have demonstrated increased motion at the lumbosacral junction with the standard chairback-type brace.
Question 2316
Topic: 6. Spine
An adult patient with a grade I isthmic spondylolisthesis at L5-S1 is most likely to have weakness of the:
Correct Answer & Explanation
. extensor hallucis longus.
Explanation
Adult patients with isthmic spondylolisthesis most commonly have neurologic symptoms due to foraminal stenosis at the level of the spondylolisthesis. In this scenario, the patient is most likely to have weakness of the L5 myotome, which would cause weakness of the extensor hallucis longus.
Question 2317
Topic: 6. Spine
What is the most important consideration in the preoperative evaluation of a child with polyarticular or systemic juvenile rheumatoid arthritis (JRA)?
Correct Answer & Explanation
. Cervical spine assessment
Explanation
The cervical spine may be involved in a child with polyarticular or systemic JRA; fusion or instability can occur. Radiographic assessment of the cervical spine should include lateral flexion-extension views. The potential exists for spinal cord injury during intubation or positioning in the presence of an unstable cervical spine. Limitations of the TMJ and micrognathia may affect ease of intubation and administration of anesthesia via a mask. If the TMJ and jaw are involved, some patients may have dental findings such as dental caries and even abscesses which can affect surgery. Some children, particularly those with systemic arthritis, may be taking corticosteroids long-term and may need stress dosing with complex surgeries. Although it is important to routinely check for uveitis and iritis in children with JRA,this usually is not needed preoperatively. Uveitis and iritis are less likely in a child with systemic JRA.
Question 2318
Topic: Thoracolumbar Spine & Deformity
A 45-year-old woman has idiopathic scoliosis. Surgery is to include an anterior thoracic release through an open left thoracotomy. The thoracotomy will have what effect on the patient’s pulmonary function postoperatively? Review Topic
Correct Answer & Explanation
. Unaffected
Explanation
A thoracotomy in an adult with idiopathic scoliosis causes a reduction in pulmonary function that often does not return to preoperative levels. What pulmonary function that does recover, recovers over many months. Long-term improvement in pulmonaryfunction, compared to preoperative function, is rarely seen. This should be considered in planning surgical intervention in adults with scoliosis.
Question 2319
Topic: Cervical Spine
A 29-year-old man reports a 2-week history of severe neck pain after being struck sharply on the back of the head and neck while moving a refrigerator down a flight of stairs. Initial evaluation in the emergency department revealed no obvious fracture and he was discharged in a soft collar. Neurologic examination is within normal limits, and radiographs taken in the office are shown in Figures 21a through 21c. Subsequent MRI scans show intra-substance rupture of the transverse atlantal ligament. What is the most appropriate treatment option at this time?
Correct Answer & Explanation
. Surgical stabilization
Explanation
DISCUSSION: Dickman and associates classified injuries of the transverse atlantal ligament into two categories. Type I injuries are disruptions through the substance of the ligament itself. Type II injuries render the transverse ligament physiologically incompetent through fractures and avulsions involving the tubercle of insertion of the transverse ligament on the C1 lateral mass. Type I injuries are incapable of healing without supplemental internal fixation. Type II injuries can be treated with a rigid cervical orthosis with a success rate of 74%. Surgery may be required for type II injuries that fail to heal with 3 to 4 months of nonsurgical management.
Question 2320
Topic: 6. Spine
Posterior spinal fusion for scoliosis should be performed on a patient with Duchenne muscular dystrophy when
Correct Answer & Explanation
. curve magnitude measures 25° or greater.
Explanation
DISCUSSION: 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° per year. Posterior spinal fusion with instrumentation should be performed as soon as a curve of 25° 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.
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