Disc Space Level Research Articles

Wrong disc space level surgery: medicolegal implications

Background Operating the wrong disc level for herniated disc disease is a rarely reported complication. However, it is considered by many a breach in the standard of care. It is not unusual for litigation to result. Sixty-nine cases of wrong disc space level surgery were identified; 68 cases were the subject of lawsuits. Methods Sixty-five lawsuit outcomes were published in a national monthly newsletter of malpractice cases, Medical Malpractice Verdicts, Settlements and Experts. Two cases came from medicolegal review, one case from a news article, and one case for which no claim was made. Results Thirty-seven cases were settled. A plaintiff verdict was rendered in 18 cases and a defense verdict in 13 cases (42% of the cases that were decided by a jury). Conclusions The authors summarize steps to reduce the incidence of this misadventure. The authors recommend that the patient be advised of this potential and the patient be informed of the risk factors when special circumstances exist.

Three-dimensional reconstruction of the knee from biplanar X-rays: Clinical evaluation: a review of seven pathological cases

Retrospective.The authors hypothesized that cervical lordosis (CL) would decrease with aging and increasing degeneration.It is theorized that with age and degeneration, the cervical spine loses lordosis and becomes progressively more kyphotic; however, no studies support these conclusions in patients with various spinal deformities.The authors performed a radiographic analysis of asymptomatic adults (referring to their cervical spine) of varying ages, with differing forms of spinal deformity to the thoracic/lumbar spine to see how cervical lordosis changes with increasing age. A total of 104 total spine EOS X-rays of adult (aged >18 years) spinal deformity patients without documented neck pain, prior neck surgery, or cervical deformity were reviewed. The researchers only reviewed EOS X-rays because they allow complete visualization from occiput to feet. Cervical lordosis, standard Cobb measurements, sagittal balance parameters, and cervical degeneration were quantified radiographically by the method previously described by Gore et al. Statistical analysis was performed with 1-way analysis of variance to compare significant differences between groups aged <40, 40–60 and >60 years as well as changes in sagittal balance. A p-value < .05 was considered significant.Average CL actually increased with increasing age (10.3 ± 14.7, 15.4 ± 15.1, and 23.3 ± 1.6.7 for age < 40, 40–60, and > 60 years, respectively; p < .05). Average cervical degeneration score increased at all disc space levels from C2 to C7 across age groups (0.7 ± 1.2, 9.9 ± 69, and 16.3 ± 8.9 for age <40, 40–60, and >60 years, respectively; p < .01), with the highest degeneration at the C5–6 and C6–7 disc spaces (3.7 ± 3.3 and 3.2 ± 2.9, respectively; p < .01). This increase did not correlate with the increase in CL seen with aging (r = 0.02; p = .84).Cervical lordosis increased with aging in adult spinal deformity patients. There was no relationship between cervical degeneration and lordosis despite the strong relationship seen between increasing CL in older age groups.

Symptoms of thoracolumbar junction disc herniation.

A retrospective clinical review of patients with thoracolumbar junction disc herniation. To evaluate the clinical features of thoracolumbar junction disc herniation and to prepare a chart for the level diagnosis in the neurologic findings and symptoms. Thoracolumbar junction disc herniations show a variety of signs and symptoms because of the complexity of the upper and lower neurons of the spinal cord, cauda equina, and nerve roots. Furthermore, much is still unknown about thoracolumbar junction disc herniations because of their rare frequency. The clinical features of 26 patients who had undergone operations for single disc herniations at T10-T11 through L2-L3 were investigated. Affected levels were as follows: 2 patients with disc herniation at T10-T11 disc, 4 patients at T11-T12, 3 patients at T12-L1, 6 patients at L1-L2, and 11 patients at L2-L3. The level of disc space of interest was confirmed with whole-spine plain roentgenograms. The caudal end of the cord was judged by magnetic resonance imaging and computed tomographic myelogram. Two patients with T10-T11 disc herniation showed moderate lower extremity weakness, increased patellar tendon reflex, and sensory disturbance of the entire lower extremities. Three of four patients with T11-T12 disc herniation experienced lower extremity weakness, and three patients had accentuated patellar tendon reflex. Sensory disturbance was observed in the anterolateral aspect of the thigh in one patient and on the entire leg in three patients. Bowel and bladder dysfunction was noted in three patients. In the T12-L1 disc herniation group (n = 3), muscle weakness and atrophy below the leg were advanced, and bowel and bladder dysfunction were also noted. Two of these three patients had bilateral drop foot, and one patient had unilateral drop foot; sensory disturbance was noted in the sole or foot and around the circumference of the anus, and the patellar tendon reflex and Achilles tendon reflex were absent. All six patients with L1-L2 disc herniation showed severe thigh pain and sensory disturbance at the anterior aspect or lateral aspect of the thigh. On the other hand, there were no clear signs of lower extremity weakness, muscle atrophy, deep tendon reflex, or bowel and bladder dysfunction in these patients. In the L2-L3 disc herniation group (n = 11), all patients had severe thigh pain and sensory disturbance of the anterior aspect or the lateral aspect of the thigh. Weakness in the quadriceps was noted in five patients and weakness in the tibialis anterior in two patients. Decreased or absence of patellar tendon reflex was observed in nine patients. Five patients had positive straight leg raising test results, and eight patients showed positive femoral nerve stretch test results. Among thoracolumbar junction disc herniations, T10-T11 and T11-T12 disc herniations were considered upper neuron disorders, T12-L1 disc herniations were considered lower neuron disorders, L1-L2 disc herniations were considered mild disorders of the cauda equina and radiculopathy, and L2-L3 disc herniations were considered radiculopathy. These findings had relatively distinct differences among herniated disc levels.

Clinical Significance of Cervicomedullary Deformity in Chiari II Malformation

Objective: The purpose of this study was to determine if there is a difference in the caudal extent of brain stem herniation and the degree of cervicomedullary deformity between symptomatic and asymptomatic Chiari II patients. Methods: Magnetic resonance imaging and the clinical presentation of 14 symptomatic and 59 asymptomatic patients were analyzed. The level of the cervicomedullary deformity below the foramen magnum was measured in both groups. The level of the deformity was identified by the cervical vertebral body or disc space level. Results and Conclusion: Review of our results shows no obvious relationship between the level of cervicomedullary deformity and the presenting symptoms or the outcome after surgical decompression. We conclude that the level of herniation and the cervicomedullary deformity is not a reliable marker to determine which patients may become symptomatic and require decompression or to determine prognosis.

Evaluation of the role of magnetic resonance myelography in lumbar spine imaging.

The purpose of our study was to evaluate the accuracy of MR myelography in depicting disc herniation in the lumbar spine when compared with conventional MRI in patients presenting with clinical evidence of disc herniation. One hundred patients referred for conventional MR imaging of the lumbar spine also had coronal MR (TR 9000 ms, TE 272 ms eff, NEX 3, echo train length 32) myelography performed. Three experienced observers compared magnetic resonance myelography (MRM) with conventional lumbar spine MR using the following variables: visibility of thecal sac and nerve roots, and the presence, location and severity of disc herniation. Disc protrusions were seen at 110 disc space levels on conventional MR images as opposed to 93 on MRM. However, only 72 % of lesions seen on conventional MR were diagnosed by MRM. Similarly, only 63.8 % of nerve root compression abnormalities seen at conventional MR were visualized when compared with conventional MRM. The sensitivity, specificity and accuracy of MRM when compared with conventional MR was 72, 93 and 85 %, respectively. The MRM technique yields images that resemble conventional myelography and may be used to help confirm abnormalities seen on conventional MR in selected cases; however, the large number of false-positive and false-negative examinations indicates that caution should be used in interpreting MRM images.

Management of tight filum terminale syndrome: With special emphasis on normal level conus medullaris (NLCM)

BACKGROUND Tethered cord syndrome is classically defined as having the tip of the conus medullaris below the body of L2, instead of at the normal L1-2 disc space level. The syndrome presents most commonly with urinary incontinence. In a patient with urinary incontinence and a low-lying conus medullaris, tethered cord syndrome can be diagnosed without difficulty. However, in a patient with urinary incontinence and a hyperreflexive type of neurogenic bladder, in whom the conus medullaris is found to be at the normal level on magnetic resonance imaging, diagnosing a tethered cord can be challenging. We hypothesized that patients with hyperreflexive neurogenic bladders have a neurologic basis for their bladder dysfunction, probably secondary to tethering by a tight filum terminale, despite having a normally positioned conus medullaris. METHODS We investigated 13 patients with tethered cord syndrome with urinary incontinence. All patients underwent urodynamic tests, somatosensory-evoked potentials (SSEPs), and magnetic resonance imaging. All had normal neurologic exams including lower extremity motor, sensory, and reflex functions. To minimize disturbance of the normal anatomy, we used a flavotomy approach and transected the tight filum terminale to release the tethered conus medullaris. RESULTS We show that urodynamic studies appear to be more predictive of a tight filum terminale than SSEPs. However, pathological SSEP results seem to correlate with poor surgical outcomes. Ninety-three percent of operated patients were continent by the first post-surgical day. However, disappointingly, almost half lost continence within the first month after surgery. CONCLUSION In cases of incontinence with a normal level conus medullaris, but urodynamic studies showing a hyperreflexic neurogenic bladder, we believe that sectioning of the filum terminale often improves continence.

SPINAL CORD TUMOR WITH SCALLOPING OF THE VERTEBRAL BODIES : TWO CASE REPORTS

We present two patients with spinal cord tumors that caused scalloping of the vertebral bodies.One patient had multiple cystic tumors in the thoraco-lumbosacral region associated with von Recklinghausen's disease, and the other had multiple tumors in the thoracolumbar region.Both patients showed dural ectasia, probably due to chronic intraspinal hypertension.According to Hadley, scalloping is visualized as erosion of the posterior surfaces of the vertebral bodies on conventional lateral X-ray films.In case one, scalloping of the vertebral bodies was combined with erosion of the articular processes and laminae with no evidence of discal destruction, and dural ectasia was also noted at the disc space level.

Clinical and radiological evaluation of lumbosacral motion below fusion levels in idiopathic scoliosis.

The purpose of this study was to evaluate the unfused segments of the lumbar spine in patients who had Harrington instrumentation and fusion for idiopathic scoliosis. Forty-eight patients, with an average follow-up of 11 years, were evaluated. The translational motion in the unfused segments below the instrumented levels was measured, using lateral flexion and extension radiographs of the lumbar spine. This motion was compared with values obtained from an earlier study of asymptomatic nonscoliotic individuals. The amount of disc space narrowing, retrolisthesis, length and level of the fusion, and the presence of traction spurs also were recorded. The incidence of low-back pain was highest in those patients fused to L4 (62%). Individuals instrumented and fused to L3 or L4 had significantly more translational motion in the adjacent lower interspace when compared with the control group (P = 0.05 and P = 0.001, respectively). Increased translational motion correlated with the presence of low-back pain in patients fused to L4. Retrolisthesis occurred in 81% of patients instrumented to L4, in 40% of those fused to L3, and was not found in patients fused to high levels. Its presence was strongly associated with low-back pain. There was no relationship between low-back pain and traction spurs, length of the fusion mass, lumbar lordosis, or width of the disc space in the unfused lower levels. The authors conclude that retrolisthesis and increased translational motion are important factors in determining low-back pain following surgery for idiopathic scoliosis. Instrumentation to L4 should be avoided if possible.