6. Spine MCQs

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.

The structure shown is the exiting nerve root at the L3-4 disk, which is the right L3 root.

The patient has symptoms that are more consistent with vascular claudication than with the pseudoclaudication anticipated from lumbar spinal stenosis. Therefore, the patient is a candidate for further vascular work-up. The radiographs reveal early spinal stenosis and spondylolisthesis at L4-5 but also show significant calcification of the iliac arteries, suggestive of peripheral vascular disease. Vascular claudication is a manifestation of peripheral vascular disease and presents with crampy leg pain that is exacerbated by physical exertion. The pain is easily relieved by standing still or sitting. Unlike pseudoclaudication, a forward-flexed posture and/or sitting does not improve the symptoms. Night pain is common in vascular claudication due to the elevation of the extremities and patients often report pain improvement by hanging their extremities in a dependent position. In evaluation of a patient with suspected vascular claudication, the five “P’s” of vascular insufficiency should be monitored, including pulselessness, paralysis, paresthesia, pallor, and pain. While pain and paresthesias can be common in both vascular claudication and pseudoclaudication, the presence of any of the remaining symptoms is suggestive of vascular disease.

The ligaments shown are the components of the lateral collateral ligament complex, and the structure indicated by the letter “A” is the radial collateral ligament. The lateral ulnar collateral ligament is the structure indicated by the letter “C” and the annular ligament is indicated by the letter “B.” The transverse ligament is a component of the medial collateral ligament complex.

Humphreys and associates in a retrospective review of TLIF vs PLIF found fusion rates, surgical time, and length of hospital stay were similar with both procedures. The only benefits associated with TLIF were less blood loss and preservation of the paraspinal muscle sleeve. Manos and associates in a cadaver study found no difference in the volume of disk material evacuated or the area of endplate exposed in either procedure.

Jehovah’s Witnesses will not accept the transfusion of blood or blood products such as packed red or white cells, platelets, or plasma. However, many Jehovah’s Witnesses will accept the use of a cell saver in a closed circuit.

This injury pattern represents a flexion distraction injury, or a Chance fracture. The imaging hallmark of this injury is the axial split of the pedicle seen on the sagittal CT scan. This injury necessitates surgical intervention to prevent progressive deformity and pain. A rotation mechanism results in a dislocation with a rotational deformity at the level of injury. An extension force causes failure of the anterior column in tension with compression of the posterior column. An axial load force would result in a burst fracture.

DISCUSSION: In approximately 15% of children with Down syndrome, atlantoaxial instability develops because of ligament laxity, making them susceptible to spinal cord injury with relatively minor trauma. The American Academy of Pediatrics recommends lateral flexion-extension views of the cervical spine in any patient with Down syndrome who wishes to participate in sports. A normal ADI is up to 4 mm. Patients with Down syndrome with an ADI of more than 5 mm should not participate in contact sports or sports with a high risk for neck injury, such as diving, gymnastics, high jump, or butterfly stroke. Cervical fusion has a very high rate of complications in patients with Down syndrome and is recommended only for patients who have myelopathic signs or symptoms.

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.

DISCUSSION: Ligamentous laxity and muscle hypotonia seen in Down syndrome contribute to the incidence of hip subluxation and dislocation. These factors can be progressive and lead to degenerative arthritis in adults with Down syndrome. Because this patient has a progressive limp and decreased endurance, observation and a shoe lift are not options. Bracing may be an option in the younger child before significant bony changes occur. Surgical intervention is the treatment of choice in this patient; however, all components of the deformity need to be addressed. Because of the increased capsular laxity, there is a high likelihood of recurrence if capsulorrhaphy is not included with the pelvic and femoral osteotomies. Surgery in these patients is associated with a high rate of complications.

DISCUSSION: Slip angle has been shown to be highly predictive of the risk for increased slippage in patients with spondylolisthesis. None of the other radiographic parameters listed has been shown to be predictive of the risk for increased slippage.

The patient has symptoms and examination findings of acute brachial neuritis which is often a diagnosis of exclusion. The recent viral flu-like symptoms have shown a correlation with the development of this disorder. The acute, severe shoulder weakness excludes calcific tendinitis, impingement, and poliomyelitis. A normal cervical spine examination makes cervical disk disease unlikely.

DISCUSSION: The patient has previously undiagnosed ankylosing spondylitis. Radiographs reveal nonmarginal syndesmophytes throughout the lumbar spine. The CT scan reveals a nondisplaced 3-column fracture. In patients with ankylosing spondylitis, this represents an unstable injury and a high likelihood of displacement with nonsurgical treatment. Surgical treatment in the form of a posterior spinal fusion is indicated. Because the fracture is nondisplaced and the patient is neurologically intact, decompression via an anterior approach is not indicated. Bracing either with a TLSO brace or a soft corset will not provide sufficient stability for this fracture pattern.

The CT scans show a burst fracture of L1. In distinction from a fracture-dislocation, the levels above and below the injury (T12 and L2) are reasonably well-aligned, although there is a marked amount of kyphosis. The axial image displays retropulsed bone fragments from the posterior vertebral body that are causing nearly 100% canal compromise. As the patient has an incomplete neurologic injury (evidenced by some motor [toe flexion, S2] and sensory [perianal sensation, S3-5] function below the level of the injury), a decompressive procedure should be strongly considered. Studies have demonstrated that an anterior corpectomy achieves the most complete spinal canal decompression after a burst fracture, and is best performed in concert with a stabilization procedure. Posterior stabilization and fusion without laminectomy could restore alignment and provide stability, but it is unlikely to provide adequate spinal canal decompression. Anterior stabilization and fusion, without decompression, would not maximize neurologic recovery. Nonsurgical treatment in a patient with an incomplete neurologic injury should be considered only for those who are medically unfit for surgery. Multilevel laminectomy will cause further destabilization of the spine and will not adequately decompress the spinal canal because the dural sac is being compressed along its anterior aspect by retropulsed bone fragments.(SBQ12SP.25) A 63-year-old female undergoes lumbar decompression and instrumented fusion for the condition shown in Figure A and B. Which of the following factors are associated with increased risk of early post-operative complications?Review TopicIncreasing AgeIntraoperative blood lossNumber of levels fusedAll of the aboveAge, intraoperative blood loss, and number of spinal levels fused are associated with increased rates of inpatient complication following lumbar decompression and fusion for degenerative spondylolisthesis. Older age correlates with the highest risk for complications.Lumbar decompression and fusion is well supported in the literature to be effective in the treatment of degenerative spondylolithesis when nonoperative modalities fail. Common complications associated with lumbar decompression and fusion include asymptomatic or symptomatic pseudarthroses (estimated 5-30%), surgical site infection (0.10-2%),and adjacent level degeneration (2-3%). Age, intraoperative blood loss, longer operative times, number of levels fused are associated with increased risk of complication. Smoking is associated with worse outcome after surgery.Kalanithi et al. reviewed the Nationwide Inpatient Sample adminstrative data on sixty six thousand patients undergoing lumbar laminectomy and fusion. They found the increased age and having 3 or more medical comorbidities was associated with increased risk of complication.Carreon et al. reviewed cases of ninety eight patients who underwent laminectomy and fusion for lumbar degenerative disease. They found that rates of major and minor complication increased with older age, increased blood loss, longer operative time, number of levels fused.Figure A is a AP lumbar spine radiograph. Figure B is a lateral lumbar spine radiograph showing degenerative spondylolisthesis at L4-L5. Illustration A shows the postoperative images of the patient treated with an L4-5 fusion with an interbody device.Incorrect

Laminoplasty or any posterior decompressive procedure is contraindicated in patients with cervical spondylotic myelopathy and cervical kyphosis. The residual kyphotic posture of the cervical spine results in persistent spinal cord compression. The other choices are not contraindications for laminoplasty. Concomitant cervical radiculopathy can be addressed at the time of laminoplasty with a keyhole foraminotomy.

DISCUSSION: Surgery is indicated for congenital kyphosis once the deformity reaches a certain size or if significant progression is documented. In a young patient with a relatively small deformity, the treatment of choice is isolated in situ posterior fusion and postoperative immobilization. If an adequate posterior fusion can be obtained, an epiphyseodesis effect can be generated, allowing the remaining anterior growth to cause some correction. Because there is no evidence of neurologic compression and the deformity is less than 50 degrees, anterior surgery is not indicated. There is no role for bracing in the management of congenital kyphosis. REFERENCES: Winter RB: Congenital Deformities of the Spine. New York, NY, Thieme-Stratton, 1983, pp 229-261. Winter RB, Moe JH: The results of spinal arthrodesis for congenital spinal deformity in patients younger than five years old. J Bone Joint Surg Am 1982;64:419-432.

Treatment is based on the probability of curve progression. Major factors that influence curve progression are skeletal maturity, curve magnitude and curve type. Candidates for bracing are Risser 0, 1, or 2 and have a curve in the range of 20-40 degrees. Patients who present with curves between 30-40 degrees should be braced on presentation. Acceptable frequency of follow-up visits are at 4-6 month intervals. MRI scan would be indicated to evaluate a patient with atypical scoliosis, the patient described is a fairly typical scoliosis patient. Scoliosis treatment by electrical stimulation or physical therapy has not been shown to be effective.

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.

Several studies have shown that sitting ability by age 2 years is highly prognostic of walking. Molnar and Gordon reported that children not sitting independently by age 2 years had a poor prognosis for walking. Wu and associates reported that children sitting without support by age 2 years had an odds ratio of 26:1 of walking compared with those unable to sit. This was far higher than the odds ratios for cerebral palsy location, motor dysfunction, crawling, creeping, scooting, or rolling.(SBQ13PE.27) A 15-year-old male patient presents requesting clearance to perform in the Special Olympics. He has had abnormal facies, has had mental developmental delay and cytogenetic analysis confirmed abnormalities on chromosome 21. Orthopaedically, he has been treated in the past for an elbow dislocation as well as bilateral patellar dislocation. He has already visited his cardiologist and endocrinologist and has been cleared. He has no complaints, denies any pain, difficulties with walking and reports that his training has been going well. What is the next best step?Review TopicWith a normal physical exam, patient can be cleared for participationMRI bilateral knees and elbow to ensure no ligamentous injuryReferral to a neurologist for clearanceLateral cervical spine flexion and extension radiographsAP pelvis radiographRuling-out C1-C2 instability with flexion/extension radiographs is necessary prior to any spine surgery or participation in sports in patients with Down's Syndrome.Patients with Down's Syndrome typically present with generalized ligamentous laxity and decreased tone. Thus, dislocations (elbow or patella) along with asymptomatic instability in the cervical spine can commonly occur. Imaging analysis is necessary prior to sports participation.McKay et al. performed a systematic review to summarize all congenital causes of cervical instability. They found in Down's patients, cervical instability due to ligamentous laxity is found mostly at C1-2. They recommend asymptomatic patientswith an ADI <4.5mm can resume unrestricted activities, while asymptomatic patients between 4.5-10mm should not participate in contact sports. With ADI >10mm OR symptoms/cord changes on MRI, surgery is recommended. Symptomatic patients with ADI between 4.5-10mm should be observed with activity restriction.Dedlow et al. outlines the most recent 2011 update and guidelines for cervical instability in Down's syndrome patients. One of the major highlighted changes is the emphasis placed on radiographic re-examination, regardless of prior clearance. Re-examination should occur prior to participation in sports and/or the onset of new symptoms.Illustrations A, B and C highlight the C1-2 instability on flexion-extension lateral radiographs. Careful attention can be placed on the relationship of the anterior arch of C1 and the dens (Illustration C). This allows for the measurements of ADI and the space available for the cord (SAC), which is highlighted in Illustration D.Incorrect answers: