Kazuo Hiroshima

Morphometry of the cervical spinal cord and its relation to pathology in cases with compression myelopathy.

The purpose of this study was to determine whether or not computerized tomography myelography (CTM) gave an actual size and shape of the cervical spinal cord, and whether such dimensions reflected pathology of the spinal cord in cases suffering from compression myelopathy. Spinal cord transverse area and compression ratio (sagittal diameter divided by transverse diameter) were measured as indicators of spinal cord morphology. As a basis for this study, we first performed CTM of cadaveric cervical columns and compared the actual dimensions of the spinal cord of the cadaveric specimens with the CTM image. Second, the correlations between these dimensions and pathology of the affected spinal cord were investigated. The results showed that CTM provided a precise image of the actual cross-section of the spinal cord. In 12 cadaveric specimens of cervical myelopathy examined, the transverse area and compression ratio were in good correlation with the severity of observed pathological changes.

Gadolinium-DTPA--enhanced magnetic resonance imaging of a sequestered lumbar intervertebral disc and its correlation with pathologic findings.

A 37-year-old man developed spinal nerve root compression caused by a sequestered lumbar intervertebral disc that migrated caudally away from the L5-S1 interspace of origin. Magnetic resonance imaging (MRI) scans of the lumbosacral spine after administration of gadolinium-DTPA (Gd-DTPA) revealed intense peripheral, but not entire, enhancement of an extradural defect. The result of examination using Gd-DTPA-enhanced MRI increased the certainty of preoperative diagnosis of sequestered disc. Pathologic examination of the resected specimen showed that the extradural defect was sequestered disc material covered with vascularized granulation tissue, and indicated that the intense peripheral enhancement of the extradural defect in Gd-DTPA-enhanced MRI was related to the accumulation of contrast material within the vascularized granulation tissue surrounding the avascular sequestered disc material.

Five-year outcomes of surgical treatment for degenerative lumbar spinal stenosis: a prospective observational study of symptom severity at standard intervals after surgery.

Study Design. A prospective observational study of patients undergoing surgery for degenerative lumbar spinal stenosis. Objective. To determine whether the long-term outcomes differ as a function of age and gender. Summary of Background Data. The long-term results of surgery for lumbar spinal stenosis are not well understood, and the patient characteristics that predispose patients to worse outcomes are unknown. Methods. Seventy patients who underwent decompressive laminotomy with or without arthrodesis for degenerative lumbar spinal stenosis were prospectively studied at standard intervals after surgery with respect to symptom severity rated on a visual analog scale (VAS). Results. The VAS scores for younger patients improved steadily for 3 or 6 months, after which the improvement was maintained until 60 months. The VAS scores for older patients showed a similar time course until 36 months, after which the VAS scores were worse compared with those for younger patients. The VAS scores for females were worse than those for males, in three symptoms queried, at one or more of the evaluation time points. Conclusion. In patients undergoing surgery for degenerative lumbar spinal stenosis, older age predicts a greater risk of late recurrence of symptoms, and women have higher VAS scores than men after surgery.

Correlation of Patient Satisfaction with Symptom Severity and Walking Ability after Surgical Treatment for Degenerative Lumbar Spinal Stenosis

Study Design. Prospective follow-up of 83 patients who had decompressive laminotomy with or without fusion for degenerative lumbar spinal stenosis between September 1992 and September 1998. Objective. To evaluate the significance of the correlation between patient satisfaction and both the severity of postoperative symptoms and walking ability. Summary of Background Data. In clinical studies of surgery for degenerative lumbar spinal stenosis, patient satisfaction often is an item in the outcome questionnaire. However, little is known about the relationship of patient satisfaction to postoperative symptoms or functioning. Methods. Patients completed standardized preoperative and follow-up questionnaires about symptom severity, walking ability, and their satisfaction with the results of surgical treatment. The significance of the correlation of patient satisfaction with the severity of postoperative symptoms and walking ability was evaluated. Results. The mean length of follow-up was 39 months (range 12–84 months). The final questionnaire of a series was answered by 77 patients (93% of the cohort). By univariate analysis, the correlations of patient satisfaction with postoperative back pain, leg pain, numbness, subjective difficulty in walking, and walking ability were statistically significant (Spearman rank-order correlation coefficient: 0.58, 0.57, 0.53, 0.64, and 0.43, respectively). Postoperative walking ability was a weaker correlate of patient satisfaction than the severity of postoperative symptoms. By multivariate regression analysis, the only independent correlate was subjective difficulty in walking. Conclusions. In the evaluation of patient satisfaction as an outcome in patients operated on for degenerative lumbar spinal stenosis, we should keep in mind that postoperative functioning is a weak correlate of satisfaction.

The lumbar spine in spastic diplegia. A radiographic study

Some radiological features of the lumbar spine of 84 patients with spastic diplegia were compared with 50 control subjects. The average age of the patients was 20.1 years (3 to 39). Spondylolysis of the fifth lumbar vertebra was found in 21%, four times more frequently than in normal subjects. No patient under nine years of age had spondylolysis and the frequency increased with age. The average angle of lumbar lordosis in spastic patients in the standing position was greater than in normal subjects, and increased with age. The patients had a decreased sacrofemoral angle which caused an increase in Fergusons angle and explained the increased angle of lumbar lordosis.

THE CERVICAL SPINE IN ATHETOID CEREBRAL PALSY: A RADIOLOGICAL STUDY OF 180 PATIENTS

We have reviewed the cervical spine radiographs of 180 patients with athetoid cerebral palsy and compared them with those of 417 control subjects. Disc degeneration occurred earlier and progressed more rapidly in the patients, with advanced disc degeneration in 51%, eight times the frequency in normal subjects. At the C3/4 and C4/5 levels, there was listhetic instability in 17% and 27% of the patients, respectively, again six and eight times more frequently than in the control subjects. Angular instability was seen, particularly at the C3/4, C4/5 and C5/6 levels. We found a significantly higher incidence of narrowing of the cervical canal in the patients, notably at the C4 and C5 levels, where the average was 14.4 mm in the patients and 16.4 mm in normal subjects. The combination of disc degeneration and listhetic instability with a narrow canal predisposes these patients to relatively rapid progression to a devastating neurological deficit.

Patient satisfaction as an outcome measure after surgical treatment for lumbar spinal stenosis : Testing the validity and discriminative ability in terms of symptoms and functional status

Study Design. A prospective observational study of 204 patients treated surgically for lumbar spinal stenosis. Objectives. To validate a measure of patient satisfaction with outcome in terms of symptoms and functional status, investigate the association of satisfaction with treatment effect, and estimate the discriminative ability. Summary of Background Data. The properties of global measures of patient satisfaction with outcome are unknown. Methods. Patients completed preoperative and follow-up questionnaires about symptom severity, walking ability, functional status, and their overall satisfaction with the surgical results. The patients were asked a single-item question rating their satisfaction. Correlations between satisfaction and symptom severity, walking ability, and function measured by back-specific questionnaires were calculated. The associations of satisfaction with the postoperative score and the score change for each outcome measure were determined, and the discriminative ability was evaluated by the receiver-operating characteristic method. Results. The correlations with the postoperative scores were significant. Satisfaction was much more strongly associated with postoperative scores than with score changes. However, patient satisfaction did not correctly discriminate between improved and nonimproved patients. Conclusion. The single-item global measure of satisfaction with outcome was valid, but it did not reflect the treatment effect and did not correctly distinguish between clinically important changes.

Unstable cervical spine in athetoid cerebral palsy

The manifestations and pathomechanism of cervical instability of the athetoid neck in cerebral palsy (CP) patients was clarified in this study by means of static and dynamic x-ray analysis. Instability was defined as follows: 1) listhesis indicating anterior or posterior slip of more than 3 mm and/or 2) sagittal rotation between two vertebrae beyond the normal range measured by Penning. Cervical instability fitting this definition mainly took place in the upper and middle cervical disc levels, such as C3-4, C4-5, and/or occasionally C5-6. These coincide with the disc levels adjacent to the apex of the lordotic curve and/or those around the transitional vertebrae between the two reversed curves that render the cervical spine S-shaped in athetoid CP. A large facet angle at the apex vertebra facilitated anterior and/or posterior listhesis of the vertebrae. Conversely, a sudden decrease in the facet angle around the transitional vertebra in S-shaped curves precipitated deflection of the spine and increased sagittal rotation at this level. In addition to these structural abnormalities, rapid and repetitious neck movements seemed to accelerate the progression of cervical instability in athetoid CP patients.

MRI evaluation of steroid- or alcohol-related osteonecrosis of the femoral condyle

We reviewed 30 patients (46 knees) with steroid- or alcohol-related osteonecrosis of the femoral condyle. Their average age was 35 (14-61) years and the mean observation time was 7 (3-16) years. The medio-lateral extent and the anterior-posterior (AP) location of the necrotic lesion were evaluated on T1-weighted MRI and related to the collapse of the condyle. The size of the lesion was classified into three categories on the mid-coronal MRI of the femoral condyle: there were 44 small, 20 medium, and 9 large lesions. The condyle was divided into 3 zones: anterior, middle, and posterior. The location of the lesion was evaluated on the mid-sagittal image. There were 7 anterior, 9 middle, 29 posterior, 14 middle and posterior and, in 14 cases, all 3 zones were involved. 44 small lesions did not collapse, while 6/20 medium lesions and 5/9 large lesions collapsed. No lesion involving only one zone collapsed, while 4/14 lesions involving the middle and posterior zones and 7/14 lesions involving all three zones progressed to collapse. 4/6 condyles with large necrotic lesions involving all three zones collapsed. We conclude that the extent of the necrotic lesion on both the mid-coronal and mid-sagittal planes is of importance for the prognosis of osteonecrosis of the femoral condyle.

Myelopathy Due to Hypoplasia of the Atlas: A Case Report

The authors report a 73-year-old woman who had spinal cord compression develop because of hypoplasia of the atlas associated with a retroodontoid pseudotumor diagnosed by magnetic resonance imaging. Radiographs of the cervical spine showed narrowing of the spinal canal at the level of the atlas and severe osteoarthrosis of the atlantoaxial joint without atlantoaxial subluxation. A remarkable neurologic recovery followed decompressive laminectomy of the atlas with posterior occipitocervical fusion. Postoperative magnetic resonance imaging showed significant reduction of the retroodontoid pseudotumor by fusion alone. The magnetic resonance imaging finding of spontaneous reduction of retroodontoid pseudotumor after posterior fusion argues against a need for transoral removal, which has a significant complication rate.