千田 益生

We report herein the results of anterior or posterior neural decompression with spinal stabilization in 16 patients with spinal metastases. Intractable back pain was relieved in 14 patients (87.5%) and 4 had complete pain relief. Neurologic recovery was observed in 8 out of 13 patients (61.5%) who had some neurologic deficits before surgery. The activities of daily living improved in 7 of 9 (77.7%), and 5 out of 8 patients (62.5%) who had been unable to walk before surgery became ambulatory after surgery. The average operation time was 3h 15 min with an average blood loss of 2150 ml. No patient died within 1 month after surgery and the median survival was 19.1 months. The results indicated that, if properly indicated, anterior or posterior neural decompression and spinal stabilization is a safe and effective treatment for patients with spinal metastases to improve the quality of life for the patients' remaining years.

<P>In this study, 42 cases of spinal schwannomas are reviewed. We analyzed the therapeutic results of patients with spinal schwannomas in order to investigate the factors which affect the clinical outcomes. Early diagnosis and treatment could help procure a good result for the patient. The delay in diagnosis and the subsequent duration of symptoms was significantly longer in cases of lumbar lesions compared to cervical and thoracic lesions. Tumor recurrence was rare, but in some cases where complete resection was not possible, close follow-up of the patients postoperatively with MRI was indicated.</P>

To study the pathology of muscle atrophy in rheumatoid arthritis (RA), we examined the vastus medialis in rheumatoid patients histologically. The relationship of the findings to their ambulatory ability and long-term steroid therapy was investigated. The muscles of the RA patients were also compared with those of patients with osteoarthritis (OA). Specimens of the vastus medialis were collected from 29 knees of 23 patients with RA and 16 knees of 13 patients with OA during total knee arthroplasty. Muscle fibers were classified according to their type, and the ratio between the area of single type I and type II fibers as well as the ratio between the total area of these fibers was calculated. The total area of type II fibers in the RA group was significantly greater than in the OA group (P < 0.05). In the RA group, the mean proportion of the type II fibers relative to the total muscle fiber area tended to increase with the decline of ambulatory ability, while there was no such increase in the OA group. The proportion of type II fibers was increased significantly in RA patients on long-term steroid therapy when compared to those without therapy. In the ratio of the area of a single fiber, there was no clear relationship to ambulatory ability and long-term steroid therapy. It is considered that muscle atrophy in RA is not solely disuse atrophy, but also has a close relationship to steroid therapy and the pathology of the disease itself.

We observed differences in the capillary architecture of the skeletal muscles that have different fiber metabolism. The soleus, the vastus intermedius and the tibialis anterior muscles of adult Wistar rats were prepared using two different techniques. Samples for adenosine triphosphatase (ATPase) staining were prepared following Dubovitz's method, and the distributions of fiber type, Types 1, 2A and 2B, were analyzed. Then, corrosion casts of capillary architecture of these muscles prepared following Murakami's method were observed with a scanning electron microscope (SEM) and compared with the fiber distribution. The fiber type composition of the soleus muscle showed Type 1 (slow-twitch) dominance and that of the vastus intermedius and the tibialis anterior muscle showed Type 2 (fast-twitch) dominance. The capillaries of the soleus muscle were tortuous, and this was thought to be advantageous for blood supply. In contrast, the capillaries of the vastus intermedius and tibialis anterior muscles had a relatively parallel pattern. Additionally, two different patterns of capillary architecture that appeared to correspond to certain metabolic characteristic of different muscle fiber types were preserved with corrosion casting. In conclusion, comparative studies on capillary architecture of the skeletal muscles are useful for analyses of its function.

Accurate assessment of elbow function is important to determine the total ability of the arm. The purpose of this study was to clarify the relationship between isometric muscle strength of the elbows of patients with rheumatoid arthritis (RA) and Larsen's X-ray evaluation. Fifty-six elbows of 45 RA patients aged 47 to 77 years (mean age, 63 years) were tested. Muscle strength was measured with an isometric torque-cell dynamometer. Test-retest reliability of the dynamometer was proven by measuring 12 elbows of 6 healthy young men. In RA patients, elbow flexion and extension strength decreased in proportion to increases in the severity of Larsen's grades from Grade 1 to 4. However, Grade 5 elbows had greater muscle strength than those in Grade 4. Forearm pronation and supination strength also decreased in proportion to increases in the severity of Larsen's grades from Grade 1 to 5. This quantitative study made it clear that the muscle strength of RA patients' elbows almost completely correlates to X-ray finding according to the grade of Larsen's evaluation based on X-rays. With regard to muscle strength of postoperative elbows, both flexion strength and supination strength after total elbow replacement (TER) were about two times greater than before TER, and after synovectomy it was as great as those in non-operative RA patients of Grade 2.

Lumbar X-ray findings and clinical manifestations were investigated in 10 patients who underwent posterior fusion with or without Harrington instrumentation for idiopathic scoliosis between 1965 and 1975. The subjects were 4 men and 6 women, who ranged from 10 to 17 years of age at the time of surgery (mean, 12 years and 9 months). The postoperative follow-up period ranged from 20 to 30 years (mean, 24 years and 7 months). All patients were followed-up at our institution. Three patients received posterior fusion without instrumentation, and Harrington instrumentation was used in 7 from 1967 onwards. The distal end of the fusion was L2 in 4, L3 in 4, and L4 in 2 patients. Pain, evaluated by Moskowitz's criteria, was stage 1 in 5 and stage II in 5 patients (none of them had stage III or IV). In X-ray evaluation, graded according to Lawrence's classification, grade III changes were noted in 2 patients; one with thoracolumbar fusion with Harrington instrumentation to the L4 vertebra and the other patient was assessed at 30 years post-surgery. According to White-Panjabi's criteria, instability was noted in 1 patient with Harrington fixation including the L4 vertebra. Clinical manifestations and X-ray abnormalities were less severe than anticipated at 20 years plus post-surgery, although a tendency for deterioration was observed in patients with fusion including the L4 or patients followed up for more than 30 years post-surgery.

We investigated the degree of local heat and swelling of the thigh muscles produced by exercise. Eleven university athletes aged from 19 to 23 years old performed isokinetic exercise of the right knee on a Cybex II. Then serial determination of thigh circumference and thigh temperature (up to 120 min after exercise) as well as serial magnetic resonance (MR) imaging (up to 60 min after exercise) was performed on both thighs. The circumference of the right thigh peaked at 5.6 +/- 2.1 min after exercise and returned to normal at 38.6 +/- 9.2 min. The temperature of the right thigh peaked at 14.2 +/- 5.7 min after exercise and was not normalized after 120 min except in two subjects. T2-weighted MR images showed a marked increase in the signal intensity of the right knee flexor and extensor muscles. The signal intensity peaked immediately after exercise and subsequently decreased gradually but did not return to normal after 60 min in some muscles. Changes in the thigh circumference were closely correlated with changes in the MR findings. The changes in the thigh muscles after knee exercise could be demonstrated using MR imaging, thigh circumference, and thigh temperature data. These parameters may provide indicators for managing muscle fatigue and recovery.

We studied the magnetic resonance imaging (MRI) of 120 knees in 86 rheumatoid arthritis (RA) patients and of 14 unaffected knees in 12 control cases. We also developed a scoring system as a quantitative analysis method. We divided the MRI into 10 items, and classified the severity of the symptoms into 4 grades (score 0 to 3). The average total score increased according to the radiographic grade. Soft tissue lesions were clearly detected, even in the early stages of RA. Items such as synovial proliferation showed a high score even in the early stages, suggesting that it was the initial symptom of RA. The score also showed a correlation with the inflammatory signs. These results suggest that this scoring system is very sensitive and yields a good reflection of RA activity. We demonstrated that this system is simple and convenient for routine diagnostic use. We further demonstrated that it is useful for following the advancement of RA and for evaluating the response to treatment.

Conservative treatment is ineffective for ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine, and surgical treatment is indicated for most cases, while such cases are not often experienced. In the present study, the results of surgical management involving mainly posterior decompression for this disease were evaluated clinically. The study included 9 patients (1 man and 8 women) who underwent surgical treatment for OPLL of the thoracic spine between 1984 and 1993. Laminectomy was performed in 5 patients, and laminectomy plus anterior decompression of the OPLL via the posterior approach based on Otsuka's method was performed in 2 patients. In 1 patient, laminoplasty for OPLL of the cervical spine was combined with laminectomy of the symptomatic lesion in the thoracic spine. One patient underwent anterior decompression and fusion. The results were evaluated using the Japanese Orthopaedic Association score (JOA score) and recovery rate. The postoperative follow-up period ranged from 1 year to 10 years and 3 months (mean, 4 years and 6 months). The mean JOA score was 4.8 before surgery and improved to 7.6 at the final examination. This was a mean recovery rate of 50.1%. Symptoms caused by OPLL in the thoracic spine can be alleviated by posterior decompression where OPLL extends from the upper to the middle thoracic spine or extends from the middle to the lower thoracic spine. It seems, however, that OPLL localized to the middle thoracic spine requires anterior decompression.

Forty-one hands of 37 patients with idiopathic carpal tunnel syndrome treated by endoscopic carpal tunnel release (ECTR) were followed up for more than one year after surgery. Surgical results were evaluated using Kelly's criteria, the Semmes-Weinstein test, the static and moving 2-point discrimination tests, tip-pinch strength, and motor and sensory nerve conduction studies. Clinical results, according to Kelly's criteria three months after surgery, were excellent or good in 36 hands, and fair or poor in five hands. No recovery was evident at six months and 12 months after surgery in fair and poor hands. Based on these findings, we conclude that a neurolysis of the median nerve and release of constriction of the thenar muscle branch should be performed using the conventional open technique for patients with poor results three months after ECTR if the patients are dissatisfied with ECTR results

Seventy-nine shoulders suspected of rotator cuff tears were examined by ultrasonography (US) and forty-three received surgery. Long and short axis scans were performed and findings of each were separately classified according to a five-grade system, and the results were correlated with the actual extent of tear observed during surgery. Internal echogenicity and subacromial impingement were analyzed before and after surgery. A accuracy of US in detecting rotator cuff tears was analyzed. In addition, the correlation between cuff shape observed by US before surgery and actual shape observed during surgery was assessed. It was noted that cuff thinning and abnormalities in shape did not recover to normal after surgery. However, in the cases of discontinuities observed by US before surgery, US findings indicated that the torn cuff was anchored to the greater tuberosity and functional during active motion. Although post-operative US findings were not normal, clinical results were good in most cases. Sensitivity of US for detecting rotator cuff tear was 100% and specificity 94%. US is non-invasive, cost effective and allows the physician to examine the joint while it is in motion. Therefore, at this time, we use US as a screening method for detecting rotator cuff tears. Furthermore, US allows us to check for re-tears while the joint is in motion, which is essential for accurate diagnosis.

The aim of this study was to investigate the relationship between the strength of the foot muscles that control the toes and disorders such as shin splint. In order to this, we designed and built a toe dynamometer to compare the muscle power exerted through the toes in top female marathon runners and age-matched women not involved in sports. The subjects were 12 top-level female marathon runners (Group A) and 37 student nurses who were not involved in sports (Group B). We devised a dynamometer to measure the total power exerted by the flexor muscles of the 5 toes of a single foot (total flexor power) and the combined power of the abductors of the big (1st) and little (5th) toes (abductor power). In Group A, the total flexor power was 14.3 +/- 5.3 kg in the right foot and 15.4 +/- 4.7 kg in the left foot. The abductor power was 1.9 +/- 1.8 kg in the right foot and 2.2 +/- 1.9 kg in the left foot. In Group B, total flexor power was 18.3 +/- 6.7 kg in the right foot, while the abductor power was 1.9 +/- 1.7 kg. The subjects from Group A with an arch index < 1.0 (n = 8) or > 1.0 (n = 4) were respectively classified as Group I and Group II. In Group I, total flexor power was 14.9 +/- 5.3 kg (right) and 15.5 +/- 5.2 kg (left), while the abductor power was 2.6 +/- 1.9 kg (right), and 3.1 +/- 1.7 kg (left). In Group II, the total flexor power was 13.2 +/- 5.8 kg (right) and 15.1 +/- 4.2 kg (left), while the abductor power was 0.7 +/- 0.6 kg (right) and 0.3 +/- 0.2 kg (left). The abductor power of toes was significantly lower in Group II than in Group I. The incidence of posteromedial shin pain was higher in Group II (75.0%) than in Group I (12.5%).

The influence of mild exercise on skeletal muscle fibers was investigated histochemically to assess the effects of exercise on steroid myopathy and its efficacy for preventing this disease. Twenty male Wistar rats were divided into 4 groups of 5 each: group T, which received exercise alone; group S which received steroid alone; group ST which received both exercise and steroid; and group C, the control group. In groups S and ST, hydrocortisone was administered subcutaneously at a dose of 10 mg/kg/day for 4 weeks. In the exercise groups, the animals were made to run at a speed of 15 m/min for about 1 h/day for 5 days a week on a treadmill. After the completion of treadmill exercise and steroid administration for 4 weeks, the rats were anesthetized with Nembutal, the soleus muscle (SOL) and the extensor digitorum longus muscle (EDL) were removed and prepared for examinations. The area of type I fibers in the SOL was significantly larger in group ST than in group S. The area of type IIa fibers in the EDL was significantly larger in group ST than in group S. In group S, the proportion of type I fibers in the SOL was significantly lower than in the other three groups. There was little difference in fiber type distribution between groups ST and C. These results suggest that steroid myopathy can be prevented by even mild exercise.

In order to examine fatigue of the knee flexor and extensor muscles and to investigate the characteristics of muscular fatigue in different sports, a Cybex machine was used to measure muscle fatigue and recovery during isokinetic knee flexion and extension. Eighteen baseball players, 12 soccer players and 13 marathon runners were studied. Each subject was tested in the sitting position and made to perform 50 consecutive right knee bends and stretches at maximum strength. This was done 3 times with an interval of 10 min between each series. The peak torque to body weight ratio and the fatigue rate were determined in each case. In all subjects, the peak torque to body weight ratio was higher for extensors than flexors. Over the 3 trials, the fatigue rate of extensors showed little change, while that of flexors had a tendency to increase. In each subject, knee extensors showed a high fatigue rate but a quick recovery, while knee flexors showed a low fatigue rate but a slow recovery. As the marathon runners had the smallest fatigue rates for both flexors and extensors, we concluded that marathon runners had more stamina than baseball players and soccer players.

Rheumatoid arthritis (RA) is often associated with deformities of the feet, and foot pain often arises in the talonavicular joint of patients with RA. The object of this study was to assess the relationship between magnetic resonance imaging (MRI) findings of the talonavicular joint and walking ability. The subjects were 35 RA patients (10 feet in 5 males and 56 feet in 30 females) aged 34-87 years (mean: 70 years +/- 12.1), with a disease duration from 1-54 years (mean: 14 years +/- 12.1). MRI findings were classified as follows: Grade 1, almost normal; Grade 2, early articular destruction; Grade 3, moderate articular destruction; Grade 4, severe articular destruction; and Grade 5, bony ankylosis dislocation. Walking ability was classified into one of 9 categories ranging from normal gait to bedridden status according to the system of Fujibayashi. As the grade of MRI images became higher the walking ability decreased, and these parameters showed a correlation by Spearman's rank correlation coefficient analysis (P = 0.003). Thus, in the present cohort group of patients with RA, the deterioration of walking ability increased with the severity of destruction of the talonavicular joint.