Osamu Kameyama

Newly designed computer controlled knee-ankle-foot orthosis (Intelligent Orthosis)

The authors have developed a knee-ankle-foot orthosis with a joint unit that controls knee movements using a microcomputer (Intelligent Orthosis). The Intelligent Orthosis was applied to normal subjects and patients, and gait analysis was performed. In the gait cycle, the ratio of the stance phase to the swing phase was less in gait with the knee locked using a knee-ankle-foot orthosis than in gait without an orthosis or gait with the knee controlled by a microcomputer. The ratio of the stance phase to the swing phase between controlled gait and normal gait was similar. For normal subjects the activity of the tibialis anterior was markedly increased from the heel-off phase to the swing phase in locked gait. The muscle activities of the lower limb were lower in controlled force in locked gait showed spikes immediately after heel-contact in the vertical at heel-contact in the sagittal to locked gait, gait with the Intelligent Orthosis is smooth and close to normal gait from the viewpoint of biomechanics. Even in patients with muscle weakness of the quadriceps, control of the knee joint using the Intelligent Orthosis resulted in a more smooth gait with low muscle discharge.

Transcranial magnetic stimulation of the motor cortex in cervical spondylosis and spinal canal stenosis

Study Design. This study investigated the clinical usefulness of motor evoked potentials and a silent period after motor evoked potentials produced by transcranial magnetic stimulation of the brain. Objective. The results were correlated with the clinical state of the patients with myelopathy, whereas no abnormality of the conduction time was observed in the patients with spinal canal stenosis. Summary of Background Data. Magnetic stimulation has been widely used for examination of the descending excitatory motor pathways in the central nervous system, but little attention has been paid to cervical spondylosis and spinal canal stenosis. Methods. Motor evoked potentials were examined in 35 normal subjects, 67 patients with cervical spondylotic myelopathy, and 24 patients with spinal canal stenosis. Motor evoked potentials were evoked by transcranial brain stimulation during relaxation and during maximum voluntary contraction of the target muscle. Results. The central motor conduction time was found to correlate with the clinical state of the myelopathy patients, whereas no abnormality of the conduction time was observed in the patients with spinal canal stenosis. During maximum voluntary contraction of the target muscle, a silent period was always observed after the motor evoked potentials in the normal subjects, and its duration was markedly shortened in the myelopathy patients. Conclusions. In cervical myelopathy patients, the central motor conduction time was correlated with clinical evaluation and the silent period was significantly shortened. These findings about duration of the central motor conduction time and the silent period might be a useful parameter of spinal pathology.

Pseudarthrosis of the radius associated with neurofibromatosis: report of a case and review of the literature.

An 11-year-old child with pseudarthrosis of the radius associated with neurofibromatosis was treated by conventional bone graft. Five years after the operation, the pseudarthrosis united, but the grafted bone was slightly sclerotic and bowed. This article describes the clinical findings and postoperative results, and discusses the current surgical approaches in the treatment of pseudarthrosis of the radius.

Activity of rheumatoid arthritis and urinary pyridinoline and deoxypyridinoline

Abstract The aims of this study were to examine levels of the crosslinking components of collagen, pyridinoline (Pyr) and deoxypyridinoline (D-Pyr) which are bone resorption markers, in patients with rheumatoid arthritis (RA), and to determine their association with disease activity and bone mineral density (BMD). These bone resorption markers were measured in 35 postmenopausal women with RA, 30 age-matched female patients with osteoarthritis of the knee (controls), and 47 patients with bone fracture. The mean BMD in the RA patients was lower than that in the control group, and the Z-score (number of standard deviations above and below the normal mean after comparison with age and sex matched normal control values) was significantly lower. Mean levels of Pyr and D-Pyr were significantly higher in the RA patients than in the control group, and the Pyr/D-Pyr ratio was also higher in the RA patients than in the other groups. Regarding the relationship between the bone resorption markers and RA activity, Pyr increased as the Lansburys joint score (number of swollen joints corrected for joint size according Lansbury) rose, showing a normal correlation; D-Pyr also showed a normal correlation. Pyr and D-Pyr were high in patients with a high erythrocyte sedimentation rate, showing a normal correlation. Only Pyr increased with increases in C-reactive protein (CRP), showing a normal correlation. These findings suggested that a high value for Pyr (which includes a large amount of collagen type II) indicated that RA activity was affected more by synovitis, rather than by systemic osteoporosis.

Avulsion fracture of the iliac spine during sporting activity: Report of 30 fractures and their outcome

Avulsion fractures of the pelvis were analyzed in 30 adolescents (29 males and 1 female). The average age at injury was 14.4 years, and the average follow-up period was 2.6 years. We treated 20 fractures of the anterior superior iliac spine and 10 of the anterior inferior iliac spine. Eleven patients were treated by open reduction and internal fixation, and conservative treatment was selected for the remainder. The outcome was good whether the fractures were treated surgically or conservatively, and none of the patients had pain during daily activities. In 8 of the patients treated conservatively, hypertrophic deformity of the avulsed fragment was seen. However, 6 of these patients had no symptoms, while 2 noted excessive fatigue during long-distance walking. Surgical treatment may be necessary only when the displacement of a large fragment is more than 20 mm or when the patient desires to be a professional athlete. Careful observation for at least 6 months, especially of those conservatively treated, is necessary for patients who have had avulsion fracture of the iliac spine.