抄録
The criteria of indications for high tibial osteotomy include 1) pain which is not alleviated by conservative treatment, 2) a medial (lateral) space of the knee joint on weight bearing which has a less than 3mm narrowing, 3) a femorotibial angle of 180-200°, 4) a joint space on the weight shifting side in the same knee joint which has a very limited narrowing, 5) a knee flextion-contracture of less than 20°, 6) a bone defect on the knee joint surface which causes a narrowing to less than 5mm, and 7) a patello-femoral joint which has undergone a slight osteochondral change.
A total of 23 cases receiving high tibial osteotomy, in which 1 to 10 postoperative years had passed were examined. All cases suffered from osteoarthritis deformities. According to the proposition for functional estimation of the knee joint by the J.O.A, pain, range of motion, stability, walking ability, and progress of osseous changes on X-P were examined.
The dynamic changes of gait were also studied for each case by a gait analysis system.
Preoperatively, heel contact power was weak, and loading was tardive and small. The toe-off power was great, but the stance phase was short, and the braking power was weak. There were few zero-moment points while walking on the hind foot, and the weight shifting from the mid-foot to the fore-foot was unstable. A stick picture revealed that the preoperative knee angular change while walking was small and knee joint angular velocity was decreased. For those cases with a good postoperative course, knee angular change improved comparatively early, but knee joint angular velocity was recovered very slowly and its peak was low.
