Etsuo Fujimaki

Application of polyvinyl alcohol hydrogel membrane as anti-adhesive interposition after spinal surgery.

Study Design Three inflammatory and adhesive changes inside the spinal canal were analyzed histopathologically in cats. Objective To investigate the usefulness of a polyvinyl alcohol hydrogel sheet as an interposition over the dura to prevent inflammatory and adhesive reaction after laminectomy. Summary of Background Data A major concern after laminectomy is scar tissue formation that may result in extradural compression or make subsequent surgery to the same area difficult and hazardous. Methods Wide laminectomy was performed at L5 in 30 adult cats. The dura was covered with a polyvinyl alcohol hydrogel sheet, free fat graft, or without interposition as a control. Animals were killed at 3 or 12 weeks. Results In the control group, adhesion of the exposed dura was apparent. Thick, fibrous connective tissue was observed between the dura and the peravertebral muscles. In the fat graft group, the dura was separated from the scar tissue by living grafted fat. However, the dura was adherent to the grafted fat and fibroblasts migrated into the interstitial space. In the polyvinyl alcohol hydrogel group, only a thin synovium like layer was formed around the polyvinyl alcohol hydrogel sheet. Conclusions Polyvinyl alcohol hydrogel is made of water and alcohol, and has been shown to be nontoxic to tissues. This is permeable to low molecular weight, but impermeable to large cells such as fibroblasts. Thus, the polyvinyl alcohol hydrogel sheet prevents migration of inflammatory cells and subsequently reduces intraspinal canal scar tissue formation and adhesive reaction. Other beneficial properties are extreme elasticity and low friction, which elimlnate mechanical reaction to the spinal cord. The polyvinyl alcohol hydrogel sheet is believed to be useful in eliminating scar tissue formation and does not interfere with the dynamic gliding movement of the spinal cord and nerve roots.

Anterior dislocation of the shoulder joint sustained through skiing Arthrographic findings and prognosis

Over a period of 10 years we have studied 14,952 cases of skiing injuries. Of these, 660 cases (4.5%) were injuries to the shoulder with 291 cases (44.1 %) being anterior dislocations of the shoulder. One hundred forty-three cases revealed an initial dislocation (49.1 %), and 148 cases were recurrent dislocations (50.9%). We examined the arthrography of the dislo cated shoulder in 89 cases. Of these initial dislocations, one-half of the capsular detachment type were redis located, but no redislocation had occurred in the cap sular tear type. In addition, almost all of the recurrent cases were of the capsular detachment type. Thus, through arthrography of the anterior dislocated shoul der, we have been able to discover the mechanism of the dislocation and decide upon the necessary duration and method of fixation of the shoulder after reduction.

Effect of elcatonin on involutional osteoporosis

A total of 127 patients with involutional osteoporosis were randomly divided into two groups. The elcatonin group consisted of 67 patients who received 20 units of elcatonin per week administered intramuscularly, together with 0.6g calcium lactate (100mg as calcium) given orally three times daily for 24 weeks. The other 60 patients were assigned to a control group receiving 0.6g calcium lactate orally three times daily. Forty patients were withdrawn from the study treatment or dropped out during the study. The other 87 patients (consisting of 45 in the elcatonin group, and 42 in the control group) were measured for lumbar vertebral bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA). The BMD was increased significantly (P < 0.05) by 1.87 ± 0.79% (mean ± standard error) in the elcatonin group and decreased by 0.61 ± 0.93% in the control group at the end of the study. The difference between the two groups was statistically significant (P < 0.05). The results of the present study demonstrated that elcatonin increases the BMD in patients with involutional osteoporosis.

Electrophysiologic Evaluation of Intermittent Sacral Nerve Dysfunction in Lumbar Spinal Canal Stenosis

Intermittent sacral nerve dysfunction, induced by walking In lumbar spinal canal stenosis, may cause symptoms including hyperesthesia and pain in perineum, urinary bladder incontinence, and penile erection. However, it is difficult to objectively document these symptoms. Evoked external urethral sphincter potentials by cones medullaris stimulation were measured bath before walking and after walking in five patients who complained of sexual organ or urinary dysfunction during walking, and were compared with simultaneously induced sacral nerve symptom s. These potentials were al so measured during surgery. Sacral nerve symptoms wore reproduced by talking 80–350 meters (Average 177.5 m]. These potentials disappeared In one patient end were decreased in four patients at the time when the claudicant symptoms disabled the patient during walking. The amplitude subsequently recovered In keeping with relief of those symptoms during rest. Monitoring of these potentials during surgery showed an increase of amplitude shortly after the decompression procedure of the cauda equina. In conclusion, this measuring method was valuable as an objective evaluation of intermittent sacral nerve dysfunction in lumber spinal canal stenosis.

Long term observation of micturition by spinal cord transected rabbits

Neurogenic bladder was observed in chronic spinalized animals. Since these animals are difficult to maintain for long periods, there are few reports of systemic study of these preparations. We have recently observed micturition by spinalized rabbits over a period of 4 weeks. In thoracic or lumbar spinalized rabbits, urinary bladder contraction and external urethral sphincter activity were initially recorded from 1-2 days postoperative. Contraction coincided with appearance of hind-limb spasticity. This micturition was the so-called detrusor-external urethral sphincter dyssynergy with residual urine. In sacral spinalized rabbits, no micturition reflex, external urethral sphincter activity, or hind-limb spasticity were observed and the flaccid state continued for 4 weeks. It is suggested that a segmental micturition reflex pathway exists initially in the rabbit sacral cord, because reappearance of the micturition reflex was extremely quick (1-2 days) compared to that of cats (2-3 weeks). Animal hypnosis enabled immobilization during measurement without anesthetic or decerebration. Chronic spinalized rabbits, which are very intolerant to spinal damage, can be maintained alive by intensive care at and post operation and are useful for systemic study of spinal cord injury.

Regional lung perfusion and ventilation with radioisotopes in cervical cord-injured patients.

In general, cervical cord-injured patients present with restrictive pulmonary dysfunction resulting from paralysis of the intercostal muscles. Vital capacity frequently decreases below 50% of that in normal subjects, and their respiratory pattern frequently includes paradoxical movement in which the intercostal spaces sink and the abdomen distends at inspiration. Ventilation scintigraphy using Xe-133 and pulmonary perfusion scintigraphy using Tc-99m macroaggregated albumin (MAA) were performed on nine cervical cord-injured patients and four normal subjects to investigate regional lung functions in the cervical cord-injured patients. 1) Pulmonary perfusion scintigraphy, in which measurement was made in the supine position, revealed no differences between the patients and the normal subjects. 2) The inhomogeneous ventilation/ perfusion distribution was presumed to have resulted from change in regional intrapleural pressure due to paradoxical movement of the thoracic cage. 3) Washin and washout times were prolonged by paralysis of the intercostal muscles. These phenomena were particularly apparent in the upper and middle lung regions where compensating action by movement of the diaphragm is small.

Long-term morphology of spastic or flaccid muscles in spinal cord-transected rabbits

Despite difficulty in long-term maintenance of spinalized rabbits, muscular pathologic changes in chronic spinalized rabbits could be observed for a period of four weeks. Rabbits were prepared by spinal cord transection at T10 (spastic paralysis) or by spinal cord removal below L7 (flaccid paralysis). Spastic preparations showed hind-limb spasticity and reflex incontinence one to two days after operation. Hypertrophic fibers began to appear in spastic muscles after two weeks. This hypertrophy, thought to be caused by phasic repetitive contraction, was verified by electron microscopy to be different from normal exercise hypertrophy. Flaccid preparations maintained hind-limb flaccidity and overflow incontinence. In flaccid muscle, marked muscle fiber necrosis indicated rapid atrophy. Spinal deformity and joint contracture inactivate spinalized rabbits, and cause pressure sores. However, feeding assistance and avoidance of complications make long-term maintenance possible.

A CASE REPORT OF CONGENITAL ABSENCE OF THE PATELLA ANALYZED WITH MAGNETIC RESONANCE IMAGING

Congenital absence of the patella is extremely rare, and there are very few reports on this condition. We describe our experience of congenital, bilateral absence of the patella in a 17-year-old girl. Her chief complaint was an inability to run, jump, or extend her back in the standing position. Plain X-rays showed complete absence of the patella, but bones involving the pubis were present and intact. Magnetic resonance (MR) images were acquired, and this report focuses on our MR-based analysis. MR T2-weighted and proton-enhanced imaging showed a dark, low-signal band, between the quadriceps tendon and the patellar tendon with cartilaginous tissue surrounded by tendon at the junction of both tendons, 2 mm thick and 18 mm long, in place of the patella. On T1-weighted axial images, a hypoplastic patellar groove was observed, and the patella was absent. A low-signal band involved with a relatively high-signal band was noted. We concluded this to be cartilaginous tissue that may indicate cartilaginous patellar dysplasia, allowing for non-rupture of the patellar tendon.