6. Spine MCQs

DISCUSSION: The patient has juvenile scoliosis. MRI has shown an association between juvenile scoliosis and intraspinal abnormalities, most often syringomyelia and Arnold-Chiari malformations. All juvenile curves greater than 20 degrees should be evaluated with MRI despite the absence of neurologic findings.

DISCUSSION: Ankylosing spinal disorders, including ankylosing spondylitis and diffuse idiopathic skeletal hyperostosis, are conditions that make the spine rigid and at risk for 3-column unstable fractures. Spinal fractures in these patients pose high risk for complications and death and patients should be counseled and observed closely. These spine fractures often are not seen at the time of initial evaluation, and a delay in diagnosis can occur in up to 19% of cases. Advanced imaging with a CT scan or MRI should be obtained for patients with ankylosing spinal disorders even when minor injuries occur.

All of the answers except answer 3 are suggestive of vascular claudication. Additional signs and symptoms of vascular claudication include diffuse aching/cramping/tired pain that is worse with exertion, is usually in the calves (also may be in feet, thighs, hips, and buttocks). Neurogenic claudication, on the other hand, usually is sharply painful, occurs in the back, buttocks, thighs, calves; is worse with spine extension and walking; is better/less with spine flexion and lying recumbent; pulses and skin are unaffected.

DISCUSSION: Return to play decisions after traumatic spinal or spinal cord injury are not always clear-cut and often must be made on a patient-by-patient basis. Findings on MRI scans or contrast-enhanced CT scans consistent with stenosis include lack of a significant cerebrospinal fluid signal around the cord, bony or ligament hypertrophy, or disk encroachment. Based on these findings, return to play should be avoided.

DISCUSSION: In children, the main route of infection in skeletal TB is through hematogenous spread from a primary source. The mycobacterium is deposited in the end arterials in the vertebral body adjacent to the anterior aspect of the vertebral end plate. Thus, the anterior portion of the vertebral body is most commonly involved. The lower thoracic region is the most common segment; next in decreasing order of frequency are the lumbar, upper thoracic, cervical, and sacral regions. REFERENCES: Teo HE, Peh WC: Skeletal tuberculosis in children. Pediatric Radiol 2004;34:853-860. Herring JA: Tachdjian’s Pediatric Orthopaedics, ed 3. Philadelphia, PA, WB Saunders, 2002, vol 1, pp 1831-1835.

DISCUSSION: The findings and radiographic appearance are most consistent with osteoid osteoma involving the medial pedicle. Scoliosis is commonly seen with this lesion and usually does not need surgical intervention. Excellent results have been reported with surgical excision as well as with percutaneous thermocoagulation. Nonsurgical treatment also has been described in peripheral osteoid osteoma but is not well described for lesions within the spine. REFERENCES: Cove JA, Taminiau AH, Obermann WR, Vanderschueren GM: Osteoid osteoma of the spine treated with percutaneous computed tomography-guided thermocoagulation. Spine 2000;25:1283-1286. Kneisl JS, Simon MA: Medical management compared with operative treatment for osteoid-osteoma. J Bone Joint Surg Am 1992;74:179-185. Pettine KA, Klassen RA: Osteoid-osteoma and osteoblastoma of the spine. J Bone Joint Surg Am 1986;68:354-361.

DISCUSSION: The vertebral artery traverses through the arcuate foramen after exiting the lateral aspect of C1 and before entering the skull. The foramen usually is not fully formed, but a complete foramen such as this one has been reported in up to 18% of patients. REFERENCES: Stubbs DM: The arcuate foramen: Variability in distribution related to race and sex. Spine 1992;17:1502-1504. Hasan M, Shukla S, Siddiqui MS, et al: Posterolateral tunnels and ponticuli in human atlas vertebrae. J Anat 2001;199:339-343.

This patient has a large cerebral palsy (CP) scoliotic curve with pelvic obliquity. Posterior instrumentation should be from T2 to the pelvis.Scoliosis in CP differs from adolescent idiopathic scoliosis. Curves can be classified into double curves (thoracic and lumbar) with minimal pelvic obliquity (Weinstein Group I) and large curves (lumbar/thoracolumbar) with marked pelvic obliquity (Group II). In the presence of pelvic obliquity (>15°), caudal instrumentation should end at the pelvis to reduce the risk of pseudoarthrosis and late loss of correction. Cephalad instrumentation should end high in the thoracic spine (T2) to decrease proximal junctional kyphosis.Imrie et al. reviewed the management of spinal deformity in CP. They advocate posterior-only pedicle screw fusion for curves <100° that bend down to 50% on traction films, from T2-3 to the pelvis, using iliac screws. They advocate single-stage anterior release and posterior fusion for curves >120° with poor flexibility, or associated severe pelvic obliquity or sagittal deformity.McCarthy et al. reviewed scoliosis in CP. They advocate proximal fixation to the upper thoracic spine (T1-2), and distal fixation to L4-5 (pelvic obliquity <15°) or to the pelvis (pelvic obliquity >15°). They add anterior release for larger, rigid curves that do not bend out to <60°, and in skeletally immature children.Figures A and B are PA and lateral scoliosis radiographs demonstrating 75° of thoracolumbar scoliosis and severe pelvic obliquity, and progressive lumbar hyperlordosis. Illustrations A and B are PA and lateral scoliosis radiographs demonstrating correction of curve and pelvic obliquity using the Galveston Technique with segmental fixation utilizing sublaminar wires.Incorrect Answers:(SBQ12SP.26) Figure A is a lateral cervical spine radiograph of a 70-year-old female who presents with two months of posterior midline neck pain that is worse with motion. She has no history of trauma. She denies any symptoms of arm pain, gait instability, or dexterity problems with her hands. Physical exam of the lower extremities shows 2+ patellar reflexes and flexion of the great toe with a Babinski test. What should the patient be told regarding these radiographic findings?ReviewTopicShe requires surgical decompression to prevent progressive neurologic deterioration85% of individuals over the age of 60 years of age demonstrate these findingsShe is indicated for MRI to rule out cervical radiculopathyShe would benefit from modalities such as heat, cold, and transcutaneous electrical stimulationShe has <10% chance of having symptomatic improvement with non-operative treatmentThe patient has symptomatic cervical spondylosis. She should be told that 85% of asymptomatic individuals over the age of 60 demonstrate these radiographic findings.Cervical spondylosis is defined as age-related degenerative changes within the cervical spinal column. It can present as axial neck pain, cervical radiculopathy, cervical myelopathy, or as a combination of each. Radiographs demonstrate loss of disc height, arthrosis of the facet and uncovertebral joints, and endplate sclerosis. Imaging such as cervical spine radiographs and MRI should be interpreted carefully and correlated with clinical symptoms, as radiographic evidence of spondylosis is frequently seen in asymptomatic patients.Boden et. al. reviewed the cervical MRI of 63 asymptomatic volunteers with no history of cervical spine symptoms. Of those, 19% were interpreted as having an abnormality. These findings included herniated nucleus pulposus, bulging disc, and foraminal stenosis. 60% of patients over 40 years demonstrated disc degeneration or narrowing at one level.Rao et al. reviewed the presentation, pathogenesis, and management of cervical spondylosis. In this review, they report that 85% of patients older than 60 years demonstrate cervical spondylosis on radiography.Figure A is a lateral cervical spine radiograph demonstrating spondylosis at multiple levels. There is disc height loss, facet sclerosis, and anterior osteophyte formation.Incorrect Answers:

DISCUSSION: There is a high incidence of intraspinal anomalies in patients with congenital scoliosis and kyphosis. Bradford and associates reported an incidence rate of 38% in 42 patients. The MRI scan shows that the filum terminale is thickened and adherent distally in the spinal canal. Although the conus is at L1, which may be normal, neurologic dysfunction may occur with further growth. There are no signals of high intensity within the cord that would suggest a syrinx. A Chiari II malformation would be found in the upper cervical region, not shown in this MRI scan. Meningocele and diastematomyelia are not present. REFERENCES: Bradford DS, Heithoff KB, Cohen M: Intraspinal abnormalities and congenital spine deformities: A radiographic and MRI study. J Pediatr Orthop 1991;11:36-41. Mimaston MJ: Occult intraspinal anomalies and congenital scoliosis. J Bone Joint Surg Am 1984;66:588-601.

DISCUSSION: Tuberculosis of the spine is seen in 50% to 60% of skeletal disease and is most commonly found in the lower thoracic or upper lumbar spine. Typically two or more adjacent bodies are involved as seen in this MRI scan. The disk space is narrowed but still relatively preserved as opposed to pyogenic infections (black arrow). Epidural extensions often spread from vertebrae to vertebrae (white arrow); however, the posterior elements are not frequently involved (arrowhead). Tumors rarely spread to adjacent vertebrae. The anterior and posterior spread of the infectious process rules out trauma. REFERENCES: Boachie-Adjei O, Squillante RG: Tuberculosis of the spine. Orthop Clin North Am 1996;27:95-103. Currier BL, Eismont FJ: Infections of the spine, in Rothman RH, Simeone FA (eds): The Spine. Philadelphia, PA, WB Saunders, 1992, p 2614.

Discussion: In cadaveric studies, unilateral facetectomy, or excision of 50% or more of both facets, significantly decreases the biomechanic integrity of the motion segment and may increase the risk of iatrogenic instability. Sacrifice of the spinous process, interspinous ligaments, and ligamentum flavum weakens the motion segment but does not increase the risk for instability. Facetectomy, even unilateral, predisposes the patient toward lumbar instability. Reference: Abumi K, Panjabi MM, Kramer KM, Duranceau J, Oxland T, Crisco JJ: Biomechanical evaluation of lumbar spinal stability after graded facetectomies. Spine 1990;15:1142-1147.

The MRI scans reveal advanced degenerative disk disease at L5-S1. Nonsurgical management has failed to provide relief and the patient is quite debilitated as a result of her back pain. Fritzell and associates demonstrated that in a well-informed and selected group of patients with severe low back pain, lumbar fusion can diminish pain and decrease disability more efficiently than commonly used nonsurgical treatments.In a recent updated Cochrane Review of surgery for degenerative lumbar spondylosis, it was noted that while Fritzell and associates appeared to provide strong evidence in favor of fusion, a more recent trial by Brox and associates demonstrated no difference between those patients undergoing lumbar fusion compared to those receiving cognitive intervention and exercise. The Cochrane Review suggests that this may reflect a difference between the control groups. Fritzell and associates compared lumbar fusion to standard 1990s “usual care,” whereas Brox and associates compared lumbar fusion to a “modern rehabilitation program.” Bear in mind that this patient is a certified athletic trainer and runs a hospital health fitness department; therefore, at least for purposes of this question, it can be assumed that she has participated in a “modern rehabilitation program.” The Cochrane Review goes on to state that preliminary results of three small trials of intradiskal electrotherapy suggest that it is ineffective and that preliminary data from three trials of disk arthroplasty do not permit firm conclusions.

DISCUSSION: The patient’s history and physical examination findings are consistent with a lumbar disk herniation at the L4-5 level. Weakness of the extensor hallucis longus and gluteus medius are consistent with an L5 lumbar radiculopathy. Nerve root tension signs are also consistent with sciatica from a lumbar disk herniation. The MRI scans confirm a posterolateral disk herniation at L4-5, which typically affects the exiting L5 nerve root.

This patient has neurogenic claudication with a degenerative spondylolisthesis. Patients with a degenerative spondylolisthesis will have the best longterm outcomes if a wide decompression is accompanied by a solid fusion.Degenerative spondylolisthesis occurs when there is anterior translation of one vertebral body (most commonly L4) on another vertebral body (most commonly L5). When this occurs, there can be compression of the traversing/caudal (L5) nerve root in the lateral recess. Because of the instability associated with this diagnosis, a fusion is needed to preserve longterm outcomes.Kornblum et al., reported on the outcomes of 47 patients with degenerative spondylolisthesis at an average follow-up of 7 years and 8 months. Excellent to good results were reported in 86% of patients with a solid arthrodesis compared to 56% of patients with a pseudarthrosis.Weinstein et al., reported the 4-year data from the SPORT study and found that patients with degenerative spondylolisthesis treated with surgery had statistically significant improvements in health related quality of life scores compared to those treated non-operatively.Figure A is an upright lateral radiograph of the lumbar spine in which a degenerative spondylolisthesis of L4 on L5 is identified. Figure B is a sagittal T2 MRI re-demonstrating the spondylolisthesis as well as spinal stenosis. FIgure C is the axial image through L4/5 demonstrating spinal stenosis; additionally, a left sided facet cyst can be seen.Illustration A and B are the postoperative films from the same patient after he underwent an L4/5 posterior decompression and instrumented fusion.Incorrect(SBQ13PE.7) A 45-year-old HIV-positive homeless man presents with increasing low back pain for the last three weeks. He now reports difficulty ambulating, fever, and loss of appetite. He denies bowel and bladder symptoms. He denies any symptoms radiating into his buttock or legs. On physical exam he has in obvious discomfort with standing which worsens in the forward flexion position. He has a normal motor and sensory exam in his lower extremities. Blood cultures are performed which come back negative. What would be the most next appropriate step in treatment?ReviewTopicBroad spectrum antibioticsIsoniazid, rifampin, and pyrazinamide therapyCT guided biopsy with culturesTechnetium bone scanAnterior corpectomy with a retroperitoneal approach, strut grafting and instrumentationThe clinical presentation is consistent with spondylodiscitis. Although the patient has risk factors for spinal tuberculosis, a CT guided biopsy should be performed to establish a diagnosis.There is an increasing incidence of TB in United States due to increasing immunocompromised population from HIV. 15% of patients with TB will have extrapulmonary involvement. 5% of all TB patients have spine involvement. With any type of spondylodiscitis the infectious organism must be identified with blood cultures or a biopsy prior to initiating treatment.Khoo et al. emphasize with the recent global pandemic of human immunodeficiency virus, the number of tuberculosis and secondary spondylitis cases is again increasing at an alarming rate. They report that medical treatment alone remains the cornerstone of therapy for the majority of Pott disease cases. Surgical intervention should be limited primarily to cases of severe or progressive deformity and/or neurological deficit.Hadjipavlou et al. performed a retrospective study of 101 cases of spondylodiscitis. They found Staphylococcus aureus was the main organism. Infection elsewhere was the most common predisposing factor. Leukocyte counts were elevated in 42.6% of spondylodiscitis cases. The erythrocyte sedimentation rate was elevated in all cases of epidural abscess.Figure A shows lumbar radiograph with a radiolucent lesion in L2 with mild loss of disc height of the L2/3 level. Figure B shows a T2-weighted MRI showing a lesion involving the L2/3 disc spaced and extending into the L2 vertebral body.Incorrect Answers:

DISCUSSION: A large annular defect at the site of a lumbar disk herniation is associated with persistent radicular pain postoperatively. Large sequestered herniations and a positive SLR preoperatively correlate with good outcomes after diskectomy. Neither symptoms of more than 3 months’ duration nor preoperative epidural steroid injections correlate with postoperative results after diskectomy.

This patient has spondylodiscitis of C5-C7 with neurological deficit, acute kyphotic deformity and anterior prevertebral and epidural abscess. The abscess and necrotic tissue need to be drained via an anterior approach, and the deformity needs to be corrected and stabilized both anteriorly and posteriorly.Spinal epidural abscesses are more common in immunodeficient patients and IV drug abusers. They result in verebral body destruction and instability. In addition to draining the abscess and necrotic bone, the instability has to be addressed by instrumentation and fusion, even in the face of infection. Structural support can include cages with morselized bone graft, or structural allograft fixation of anterior and middle column and/or pedicle screw instrumentation of the posterior column.Shousha et al. reviewed the treatment of cervical spondylodiscitis in 30 patients. They found an epidural abscess in 80% of patients, and noncontiguous discitis in 47% of cases. Thus, they recommend MRI of the entire spine in all cases, and surgery for intractable neck pain, septicemia, epidural abscess, neurological compromise, grosskyphotic deformity with extensive destruction, and failure of conservative treatment.Heyde et al. reviewed cervical spondylodiscitis in 20 patients. All cases had postoperative antibiotic therapy for 8–12 weeks. At 37 months (range 24–63), all cases went on to union and there were no recurrences of infection. There was improvement in preoperative neurological status in all cases, leading them to recommend early surgical intervention.Figure A is an MRI scan showing spondylodiscitis C5–C7 with partial destruction of the vertebral bodies and epidural abscess formation. Illustration A shows the lateral xray (left) and MRI (right) of the same patient 9 months postoperatively after corpectomy C5 and C6 and posterior instrumentation.Incorrect

According to NASCIS III, the high-dose steroid protocol involves infusion of 30 mg/kg methylprednisolone followed by 5.4 mg/kg/h for 24 hours if the patient has sustained a spinal cord injury within the last 3 hours. The drip is continued for 48 hours if administration is started between 3 and 8 hours of the onset of neurologic deficit. No benefit has been conclusively demonstrated with steroids administered beginning 8 hours or longer after injury. Steroid use is not indicated for nerve root deficits, brachial plexus deficits, or gunshot wounds.

Near complete correction and rebalancing of the spine can be achieved by hemivertebral resection that may be done as either a simultaneous or a staged procedure in the young patient. This eliminates the problem of future progression and possible development of compensatory curves. Nonsurgical management is not indicated in congenital scoliosis. Convex hemiepiphyseodesis is best suited for patients younger than age 5 years who have a short curve caused by fully segmented hemivertebrae that correct to less than 40 degrees with the patient supine. Hemiepiphyseodesis and isolated posterior fusion are not indicated.

The patient has a burst fracture with probable unilateral entrapment of the cauda equina within the elements of the fractured lamina. A dural tear is likely in this scenario as well. It is recommended that this type of burst fracture be treated surgically with laminectomy, freeing of the entrapped nerve roots, and dural repair followed by stabilization of the fracture by either a posterior or combined approach. The degree of kyphosis and the extent of anterior canal compromise does not warrant corpectomy in this patient. Therefore, after completing the laminectomy and dural repair, posterior fusion and instrumentation should be sufficient to stabilize the fracture.

The thoracic spinal cord is characterized by a variable and, at times, complicated blood supply. The artery of Adamkiewicz, also known as the great anterior medullary artery, most typically arises off the left side of the aorta between T8 and T12. It represents the sole medullary blood supply to the thoracic spine. When this artery is divided or injured, the blood supply to the thoracic cord may be interrupted.