A ETIOLOGY OF THE OSTEOARTHROTIC KNEE JOINT FROM THE VIEW POINT OF NEUROMUSCULAR REACTION
Motoharu Mitta (Department of Orthopaedic Surgery, Kobe Kawasaki Hospital, Kobe City, Japan)
Purpose: To elucidate the disturbance of the neuromuscular integrity in the osteoarthrotic knee joint, proprioception was measured. Furthermore, the response to the proprioceptive exercise was examined.
Method: Normal group, osteoarthrosis group and neurological deficit group were included in this study. Three parameters-reaction time, peak torque time and peak torque value-gained by the muscle training machine (Kawasaki Rehamate-R) were used for evaluation. These parameters were acquired by the eccentric muscular contractions (Ihara's method). Furthermore the change of these parameters in the response to the proprioceptive exercise using a balance board was observed.
Result: All three parameters of osteoarthrotic knees were inferior to normal knees, the extensor muscle group especially, responded poorly to the proprioceptive exercise.
Table 1. Each parameter before the exercise
Conclusion: These results suggested the posibility of the neuromuscular disintegration as the etiology of osteoarthrosis.
An ACL model simulating real strain state; A photoelastic study
Kouji Yamamoto (Kurume Institute of Thecnology, Kurume, Japan)
Shunji Hirokawa (Kyushu University, Fukuoka, Japan)
Takashi Kawada (Kurume University, Kurume, Japan)
Abstract; Using silicone rubber-made anterior cruciate ligament (ACL) and epoxy-resin-made knee bones casted from cadaveric knee and ligament, strain distribution and the principal strain trajetory were obtained by photoelastic coating method. The coating film, a self-setting type of polyurethane, was adhered on a model ligament with thickness from 0.5 to 0.8 mm During angles of flection from 0° to 90° and anterotibial dislocation forecasted by knee-motion simulator, put in the reflectional polar ray field of photoelastic apparatus. Isochromatics and isoclinics appeared on the ACL were observed.
Since the linearlity between isochromatic fringes and strains has been confirmed in a preliminal experiment, the quantitative strain measurement was possible. Being the polyurethane's amorphus, the strain trajectory in the model ligament would possibly coincide to the fiber direction of an actual ligament. This photoelastic coating method is capable to apply to a living tissue.
After the discrepancy of strain behaviors between the model and an actual ligament would be solved, our method would be available for clinical trainings.