Yasuhisa Tanaka

APOPTOSIS AND PROLIFERATION OF GROWTH PLATE CHONDROCYTES IN RABBITS

The growth plates of the femoral head of Japanese white rabbits aged 5, 10, 15 and 20 weeks were stained for apoptotic and proliferating chondrocytes using the TUNEL and PCNA antibody staining techniques. Both TUNEL- and PCNA-positive chondrocytes were detected in all of the specimens. The positive ratios of both stainings were calculated for the whole plate and for the resting, proliferating and hypertrophic zones. The highest ratios in both stainings occurred in the hypertrophic zone in all age groups. With growth, the TUNEL-positive ratio increased whereas the proliferating ratio decreased. We suggest that the increase in chondrocytic death by apoptosis and the decrease in cell proliferation potential led to closure of the growth plate.

Surgical results and related factors for ossification of posterior longitudinal ligament of the thoracic spine: A multi-institutional retrospective study

Study Design. Retrospective multi-institutional study Objective. To describe the surgical outcomes in patients with ossification of the posterior longitudinal ligament in the thoracic spine (T-OPLL) and to clarify factors related to the surgical outcomes. Summary of Background Data. Detailed analyses of surgical outcomes of T-OPLL have been difficult because of the rarity of this disease. Methods. The subjects were 154 patients with T-OPLL who were surgically treated at 34 institutions between 1998 and 2002. The surgical procedures were laminectomy in 36, laminoplasty in 51, anterior decompression via anterior approach in 25 and via posterior approach in 29, combined anterior and posterior fusion in 8, and sternum splitting approach in 5 patients. Instrumentation was conducted in 52 patients. Assessments were made on (1) The Japanese Orthopedic Association (JOA) scores (full score, 11 points), its recovery rates, (2) factors related to surgical results, and (3) complications and their consequences. Results. (1) The mean JOA score before surgery was 4.6 ± 2.0 and, 7.1 ± 2.5 after surgery. The mean recovery rate was 36.8% ± 47.4%. (2) The recovery rate was 50% or higher in 72 patients (46.8%). Factors significantly related to this were location of the maximum ossification (T1–T4) (odds ratio, 2.43–4.17) and the use of instrumentation (odds ratio, 3.37). (3) The frequent complications were deterioration of myelopathy immediately after surgery in 18 (11.7%) and dural injury in 34 (22.1%) patients. Conclusion. The factors significantly associated with favorable surgical results were maximum ossification located at the upper thoracic spine and use of instrumentation. T-OPLL at the nonkyphotic upper thoracic spine can be treated by laminoplasty that is relatively a safe surgical procedure for neural elements. The use of instrumentation allows correction of kyphosis or prevention of progression of kyphosis, thereby, enhancing and maintaining decompression effect, and its use should be considered with posterior decompression.

Cervical myelopathy in the Japanese.

Surgeries (1155 cases) for cervical myelopathy in a northeastern prefecture (population, 2.26 million) and surrounding areas were reviewed. The annual operation rate per 100,000 residents in the prefecture was 5.7. Most of the patients were in their sixth or seventh decade of life (27% each), but the annual operation rate per 100,000 people of each decade of age was the highest in the eighth decade (16.5 per 100,000 people). At the largest spine center, 41% of 306 patients had a preoperative disease period of more than 1 year, and 65% had severe disabilities. Anterior and posterior decompression were about equally chosen. The former, mainly indicated for younger adults and single- or 2-level spinal cord compression, led to better functional improvement. Laminoplasty (93%) was predominant over laminectomy. Forty percent of the patients had developmental stenosis; 48%, dynamic stenosis; 27%, disc herniation; 11%, segmental ossification of the posterior longitudinal ligament; 9%, continuous ossification of the posterior longitudinal ligament; 8%, posterior spur; and 4%, calcification of the ligamentum flavum. Fifty-two percent had more than 1 of these spinal diseases.

Sex steroid receptors in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a disease characterized primarily by chronic inflammatory synovitis and is well-known to be associated with significant sex differences in its prevalence and clinical features. Sex steroids have been proposed to be involved in the pathogenesis of RA, but details pertaining to the expression of sex steroid receptors in RA synovial tissue have yet to be fully characterized. In the present study, we examined oestrogen receptor (ER) alpha, ERbeta, progesterone receptor (PR) and androgen receptor (AR) mRNA expression using real-time reverse transcriptase-PCR (RT-PCR) in eight female RA synovial tissues and six female synovial tissues without inflammation, and determined immunolocalization of ERalpha, ERbeta, PR-A, PR-B and AR using immunohistochemistry in synovial tissues obtained from 22 RA patients. Real-time RT-PCR analysis demonstrated the expression of ER, PR and AR mRNAs in both RA and non-inflamed synovial tissues. Relative abundance of ER mRNAs was significantly higher in RA synovial tissue than non-inflamed synovial tissue (P<0.05). In addition, the relative ERalpha/ERbeta mRNA expression ratio was significantly lower in RA than non-inflamed synovial tissue (RA, 2.34 +/- 1.60; and non-inflamed, 20.7 +/- 19.1; P<0.05). There were no significant differences in relative abundance of PR mRNA. Relative abundance of AR mRNA was significantly lower in RA (P<0.05). Immunoreactivity for ERalpha, ERbeta, PR-B and AR was detected in the lining cells, inflammatory cells and fibroblasts in all the patients examined. The labelling indices for ERbeta and PR-B were more abundant in both lining cells (ERbeta, 54.2 +/- 12.2%; PR-B, 73.6 +/- 18.9%) and inflammatory cells (ERbeta, 74.6 +/- 16.2%; PR-B, 75.9 +/- 16.1%) than in fibroblasts (ERbeta, 36.5 +/- 15.6%; PR-B, 49.4 +/- 18.0%). Labelling indices for ERalpha and AR were significantly higher in lining cells (ERalpha, 14.4 +/- 8.6%; AR, 31.2 +/- 11.3%) and fibroblasts (ERalpha, 12.1 +/- 7.5%; AR, 20.1 +/- 9.6%) than those in inflammatory cells (ERalpha, 5.7 +/- 3.3%; AR, 9.2 +/- 4.4%). There were significant differences (P<0.05) in the labelling indices for ERalpha, ERbeta and PR-B between men and women under 50 years of age in fibroblasts of RA synovial tissues. These results indicate that sex steroid receptors are present in RA and non-inflamed synovial tissues, including inflammatory cells in RA, and suggest that sex steroids may play important roles in the regulation of inflammation of RA synovial tissue.

Idiopathic herniation of the thoracic spinal cord: report of three cases.

Study Design. Cases are reported and the literature is reviewed. Objective. To present three cases involving idiopathic herniation of the thoracic cord. Summary of Background Data. Idiopathic spinal cord herniation is a very rare condition. Only 20 cases have been reported. The radiographic and intraoperative findings concerning this herniation remain insufficient, and its pathophysiology is less understood. Methods. Idiopathic herniation of the thoracic spine was managed operatively in the three cases. The clinical, radiologic, and intraoperative features in these cases are described, and the pathophysiology of this disorder is discussed from a review of the literature. Results. Two of the three patients had a defect in the inner layer of the duplicated ventral dura mater through which the spinal cord was herniated. The third patient had a ventral epidural cyst into which the spinal cord had protruded. Operative reduction of the spinal cord improved motor power in all three patients, although sensory disturbance remained unchanged. Conclusions. There should be several types of idiopathic spinal cord herniation. This is the first report of this herniation that focuses the abnormalities of the ventral dura mater, together with image and intraoperative findings.

A diagnostic support tool for lumbar spinal stenosis: a self-administered, self-reported history questionnaire

BackgroundThere is no validated gold-standard diagnostic support tool for LSS, and therefore an accurate diagnosis depends on clinical assessment. Assessment of the diagnostic value of the history of the patient requires an evaluation of the differences and overlap of symptoms of the radicular and cauda equina types; however, no tool is available for evaluation of the LSS category. We attempted to develop a self-administered, self-reported history questionnaire as a diagnostic support tool for LSS using a clinical epidemiological approach. The aim of the present study was to use this tool to assess the diagnostic value of the history of the patient for categorization of LSS.MethodsThe initial derivation study included 137 patients with LSS and 97 with lumbar disc herniation who successfully recovered following surgical treatment. The LSS patients were categorized into radicular and cauda equina types based on history, physical examinations, and MRI. Predictive factors for overlapping symptoms between the two types and for cauda equina symptoms in LSS were derived by univariate analysis. A self-administered, self-reported history questionnaire (SSHQ) was developed based on these findings. A prospective derivation study was then performed in a series of 115 patients with LSS who completed the SSHQ before surgery. All these patients recovered following surgical treatment. The sensitivity of the SSHQ was calculated and clinical prediction rules for LSS were developed. A validation study was subsequently performed on 250 outpatients who complained of lower back pain with or without leg symptoms. The sensitivity and specificity of the SSHQ were calculated, and the test-retest reliability over two weeks was investigated in 217 patients whose symptoms remained unchanged.ResultsThe key predictive factors for overlapping symptoms between the two categories of LSS were age > 50, lower-extremity pain or numbness, increased pain when walking, increased pain when standing, and relief of symptoms on bending forward (odds ratio ≥ 2, p < 0.05). The key predictive factors for cauda equina type symptoms were numbness around the buttocks, walking almost causes urination, a burning sensation around the buttocks, numbness in the soles of both feet, numbness in both legs, and numbness without pain (odds ratio ≥ 2, p < 0.05). The sensitivity and specificity of the SSHQ were 84% and 78%, respectively, in the validation data set. The area under the receiver operating characteristic curve was 0.797 in the derivation set and 0.782 in the validation data set. In the test-retest analysis, the intraclass correlation coefficient for the first and second tests was 85%.ConclusionA new self-administered, self-reported history questionnaire was developed successfully as a diagnostic support tool for LSS.

Cartilaginous endplate in cervical disc herniation

Study Design Cervical herniated disc tissue obtained at surgery for myelopathy and intervertebral discs from autopsy cases were examined histologically. Objectives To clarify the characteristic histology of cervical disc herniation and the processes by which herniated masses are produced. Summary of Background Data Except for nucleus pulposus or anulus fibrosus, no other disc tissue has been described histologically in the cervical spine. Methods Twenty-one herniated cervical discs from 20 surgical cases (patients aged 37-68 years) and mid-sagittal slabs of 135 cervical discs from 41 autopsy cases (aged 20-85 years) were examined histologically. Results All the surgical specimens had cartilaginous endplate fragments together with nucleus pulposus or anulus fibrosus. Of the autopsy disc specimens, 61% had a horizontal cleft longer than two thirds of the anteroposterior diameter of the disc, and 49% had one or more vertical clefts extending to the cartilaginous endplate. Thirty-three percent showed separation of the cartilaginous endplate, and 15% had a herniated mass including parts of the cartilaginous endplate. These abnormal features increased with aging. The same order of decreasing frequency from horizontal cleft formation through herniation was observed in all decades. Conclusions The cartilaginous endplate-type of herniation is the predominant type of herniation in the cervical spine. It results from horizontal and vertical cleft formations of the disc.

Tumoral calcinosis in the upper cervical spine: a case report.

Study Design An elderly women with tumoral calcinosis between the C1 posterior arch and the C2 lamina is reported. Objectives To describe a rare occurrence of tumoral calcinosis in the spine and discuss its pathomechanism. Summary of Background Data Tumoral calcinosis is a rare condition occurring predominantly in the juxtaarticular regions of the extremities. Involvement of the spine has been reported in only one case in the lumbar spine. The calcium phosphate crystals that have been identified are those of hydroxyapatite. Methods The calcified material was removed, and its crystalline phase was analyzed. Results Neck pain was relieved by removal of the calcified material. Scanning electron microscopy and energy-dispersive x-ray microanalysis revealed that the material consisted of crystals of calcium pyrophosphate dihydrate. Conclusions Tumoral calcinosis should be included among the clinical presentations of calcium pyrophosphate dihydrate crystal deposition disease.

Cervical roots as origin of pain in the neck or scapular regions.

Study Design. A prospective observational study. Objectives. To determine whether the pain in the neck or scapular regions in patients with cervical radiculopathy originates from the compressed root and whether the site of pain is useful for diagnosing the level. Summary of Background Data. The pain has been thought to be caused not by root compression but by instability caused by disc degeneration or zygapophysial joint osteoarthritis because it usually precedes radicular symptoms in the arm/fingers. Methods. The subjects were 50 consecutive patients with pain as well as arm/finger symptoms, who underwent single-root decompression alone. The involved roots were C5 in 9 patients, C6 in 14, C7 in 14, and C8 in 13. Results. The pain preceded the arm/fingers symptoms in 35 patients (70%). Although the pain had lasted for more than 7 months on average before surgery, it was relieved early after surgery in 46 patients (92%). When the painful site was suprascapular, C5 or C6 radiculopathy was frequent (P < 0.01). When it was interscapular, C7 or C8 radiculopathy was frequent (P < 0.001). When it was scapular, C8 radiculopathy was frequent (P < 0.01). Conclusions. Pain in the suprascapular, interscapular, or scapular regions can originate directly in the compressed root. The site of the pain is valuable for determining localization of the involved root.

Adolescent lumbar disc herniation and hamstring tightness: review of 16 cases.

Study Design. Retrospective review. Objectives. To investigate the clinical characteristics and responses to surgical and conservative treatments of lumbar disc herniation in adolescents with hamstring tightness. Summary of Background Data. The incidence of hamstring tightness in adolescent lumbar disc herniation is much higher than that of adults. Hamstring tightness has been reported to result from nerve root or cauda equina irritation. But the clinical characteristics, prognosis, and etiologic mechanism of hamstring tightness has not been clearly investigated. Methods. Sixteen consecutive adolescents (age range, 12–18 years; mean, 15.8 years) with lumbar disc herniation were analyzed. Among them, there were 10 cases with hamstring tightness. Clinical and radiologic findings of the study group were compared with those of the remaining 6 cases. After conservative treatment, 5 cases in the hamstring tightness group were treated with discectomy, and of these, 1 case was treated with shortening osteotomy in the upper part of the bilateral femurs 10 months after the discectomy because of the persisting hamstring tightness. Another 5 discectomies were done in the nonhamstring tightness group. All patients were observed for a mean of 2.7 years (range, 0.8–6 years). Results. In all patients, the neurologic defects were improved shortly after the treatment, but the hamstring tightness continued and remained even after 1 year. The patient who underwent femoral osteotomy showed improvement. Conclusions. The incidence of hamstring tightness in adolescent lumbar disc herniation is high. The physical examination findings and prognoses of patients with hamstring tightness are different from those of simple disc herniation patients. The hamstring tightness appeared to have developed from a different mechanism.