6. Spine MCQs

Discussion: The sympathetic chain approaches the lateral border of the longus colli muscle at C6 and is more vulnerable to injury at this level. Injury to the chain will cause Horner’s syndrome, usually seen as unilateral ptosis.

Discussion: The great medullary artery originates as a direct or indirect branch of the left posterior intercostal artery, usually between T8 and T12. It becomes intradural and crosses over one to three disk spaces before turning to the midline where it anastomoses with the anterior spinal artery.

Discussion: The lateral radiograph shows 8 mm of atlantoaxial translation. In the absence of a bony injury, this represents rupture of the transverse atlantal ligament. These injuries require arthrodesis because nonsurgical measures will not provide stability.

Kondrashov and associates noted stable good outcomes at 4 years in 14 of 18 patients treated with X-STOP interspinous process decompression as defined as an improvement over preoperative Oswestry scores of 15 points or more. Similar results were seen after 1 year in a European study by Siddiqui and associates. Exclusion and inclusion criteria for these studies varied somewhat, but cauda equina syndrome was the only exclusion criteria listed in both studies. All of the other choices did not represent exclusion criteria in either study.

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

The MRI findings reveal age-related degenerative changes in the cervical spine, which is a very common finding in the adult population. Boden and associates evaluated cervical spine MRI findings on 63 asymptomatic subjects, and found that the prevalence of having at least one degenerative disk was approximately 57% in those older than age 40 years.

Surgical and nonsurgical treatment have been shown to be equivalent in terms of clinical outcome in a prospective randomized trial of stable burst fractures. There is relatively limited risk of neurologic injury with careful mobilization in appropriate bracing of patients with this injury pattern. There is only infrequent symptomatic late stenosis, with many patients experiencing resorption of the intra-canal fragments. The status of the adjacent disks has not been shown to be a prognostically important factor. The complication rates of surgical and nonsurgical treatments appear to be similar if not less for nonsurgical treatment.

During lumbar laminectomy and instrumented fusion, patients are in prone position with padded rests near the iliac crest. The lateral femoral cutaenous nerve (LFCN) is at risk of compression during surgery due to positioning.Careful patient position during orthopaedic surgery is of the utmost importance to prevent nerve injury. When patients are placed lateral for hip procedures, adequate positioning and padding of bony prominences and nerves is necessary to prevent complications. During prone position for spine surgery, the lateral femoral cutaneous nerve can be compressed under the iliac crest padded rest leading to meralgia parasthetica (MP). Numbness and tingling over the lateral thigh are usually temporary. The ulnar nerve at the elbow can also be at risk due to pressure from the positioning of the arms and the brachial plexus can be compromised by possible stretch.Cho et al. review the literature regarding development of paresthesia due to compression of the LFCN after prone positioning for spinal surgery. They reported up to 24% incidence of after surgery. Surgery longer than 3.5 hours and shorter distance between the pelvic posts were implicated in development of MP. They recommened the patient should be positioned symmetrically, with smaller bolsters under the ASIS and adequate distance between the two pelvic posts.Labrom et al. examined the use of SSEPs during scoliosis surgery to evaluate positional-related brachial plexopathy. They found that 27 of 434 patients had 30 percent or greater loss of SSEP during surgery. There was a significant association with prone versus supine positioning (p<0.01).Schwartz et al. used neurological monitoring to identify the incidence and location of position-induced nerve injury in anterior cervical spine surgery. 1.8% of 3806 patients showed evidence of impending neurological injury. The majority of these cases wereat the brachial plexus during shoulder taping and application of counter traction.Figure A is an AP lumbar spine radiograph showing intact hardware from L4-L5 laminectomy and fusion.Incorrect

With a diagnosis of neurofibromatosis and severe kyphosis, anterior and posterior treatment is needed to achieve correction and fusion. In situ fusion has a high failure rate with the kyphotic deformity and even with traction, correction of the kyphosis is not expected. Anterior treatment alone may achieve correction, but in neurofibromatosis only circumferential treatment has been shown to provide long-term stability.

DISCUSSION: Central cord syndrome is characterized by greater neurologic involvement of the upper extremities than the lower extremities. This is typically seen in older patients with cervical spondylosis without associated bony injury or joint subluxation. The prognosis for recovery is fair. Patients with Brown-Sequard syndrome have an ipsilateral motor deficit and contralateral loss of pain and temperature. Prognosis for recovery depends on the mechanism of injury, which is often of a penetrating nature. Anterior cord syndrome results from anterior compression such as occurs with a burst or teardrop fracture of the vertebral body; patients have bilateral motor loss, pain, and temperature loss with preservation of proprioception and vibratory sensation (posterior column function). The prognosis for recovery is generally poor. Posterior cord syndrome is rare and is associated with loss of posterior column function (proprioception and vibration). REFERENCES: Northrup BE: Evaluation and early treatment of acute injuries to the spine and spinal cord, in Clark CR (ed): The Cervical Spine, ed 3. Philadelphia, PA, Lippincott-Raven, 1998, pp 541-549. Schneider RC, Thompson JM, Rebin J: The syndrome of acute central cervical spinal cord injury. J Neurol Neurosurg Psychiatry 1958;21:216-227.

Neurogenic shock is defined as vascular hypotension with bradycardia as a result of spinal injury. The first few minutes after spinal cord injury are associated with hypertension and tachycardia, with a subsequent drop in pressure and pulse rate.

DISCUSSION: The patient has obvious signs of progressive myelopathy. Based on her significant physical examination findings, nonsurgical management will not significantly impact her outcome. Cervical decompression alone is contraindicated in patients with cervical kyphosis such as seen here. Anterior cervical fusion is the best option. REFERENCES: Emery SE, Bohlman HH, Bolesta MJ, et al: Anterior cervical decompression and arthrodesis for the treatment of cervical spondylotic myelopathy: Two to seventeen-year follow-up. J Bone Joint Surg Am 1998;80:941-951. Ferguson RJ, Caplan LR: Cervical spondylotic myelopathy. Neurol Clin 1985;3:373-382. Herkowitz HN: A comparison of anterior cervical fusion, cervical laminectomy, and cervical laminoplasty for the surgical management of multiple level spondylotic radiculopathy. Spine 1988;13:774-780.

Kayanja and associates, in a number of biomechanical studies, showed that in a kyphotic spine the strain is located at the apex of the deformity, the force is transmitted to the superior adjacent vertebrae, and that realignment and cement augmentation effectively normalize the load transfer.

DISCUSSION: The radiographs show L5 spondylolysis without spondylolisthesis (slip). The bone scan is normal, indicating that the pars interarticularis fractures are not acute. The incidence of spondylolysis is approximately 5% in the general population. The lesion generally develops in children age 5 to 6 years, and there is a second peak in the adolescent population. There is a familial predisposition, with reported rates of 27% to 69% in close relatives. A recent long-term follow-up study found that 90% of the spondylolisthesis had occurred before the patient’s first visit to the physician. Spondylolisthesis tends to progress during the initial growth spurt and is similar in some respects to idiopathic scoliosis. Progression of a lytic spondylolysis to spondylolisthesis in adulthood has been reported; however, this is exceedingly rare. REFERENCES: Lauerman WC, Cain JE: Isthmic spondylolisthesis in the adult. J Am Acad Orthop Surg 1996;4:201-208. Hensinger RN: Spondylolysis and spondylolisthesis in children and adolescents. J Bone Joint Surg Am 1989;71:1098-1107. Seitsalo S, Osterman K, Hyvarinen H, Tallroth K, Schlenzka D, Poussa M: Progression of spondylolisthesis in children and adolescents: A long-term follow-up of 272 patients. Spine 1991;16:417-421. Fredrickson BE, Baker D, McHolik WJ, Yuan HA, Lubicky JP: The natural history of spondylolysis and spondylolisthesis. J Bone Joint Surg Am 1984;66:699-707.

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

The presence of drainage 3 weeks after surgery is a sign of wound infection. This infection most likely involves deep tissues until proven otherwise. Oral or IV antibiotics, in the absence of debridement, are not sufficient. Removal of the hardware would lead to rapid progression of the scoliosis in a spine that has been surgically destabilized by removal of the facet joints. The appropriate treatment is debridement with wound culture, IV antibiotics, and retention of hardware. The wound should be closed over drains.

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

DISCUSSION: The radiographic findings are consistent with a type II Hangman’s fracture or traumatic spondylolisthesis of C2. This occurs with more than 3 mm of displacement according to the classification of Levine and Edwards. Even though the radiograph reveals significant displacement, the overall space available for the neural elements is increased, therefore minimizing the risk of neural compromise. Neurologic injury is most frequently encountered in type III injuries that are associated with bilateral facet dislocations of C2 on C3 but is infrequent in type I (less than 3 mm displacement) and type II traumatic spondylolisthesis. When neurologic deficits are associated with type II injuries, it is usually the result of an associated head injury. Cruciate paralysis occurs as a result of the crossover of the motor and sensory tracts at different levels of the cord at the C1-C2 junction. This results in normal sensation but complete loss of motor function.

DISCUSSION: The patient has a bilateral facet dislocation of C6-C7 with preservation of at least some neurologic function. Urgent reduction is necessary. However, because she is sedated and unable to follow commands, an MRI scan is necessary before any closed or open posterior reduction to look for an associated disk herniation. If a disk herniation is present, it must be removed prior to any reduction maneuver to prevent iatrogenic neurologic injury. It is very unlikely that this injury can be reduced with an open anterior procedure alone.

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