Comparative Studies on the Muscle Strength of the Legs of the Patients with Unilateral Femoral Head Necrosis before and after Operation

The authors investigated the muscle strength about the knee and hip joints in patients with unilateral femoral head necrosis, preoperatively and postoperatively. Results of preoperative (8 cases) and postoperative (7 cases) patients were also compared with those of normal and osteoarthritis groups using Cybex-II. The results were as follows;1) Strength of all muscles except abductor and adductor both in the affected and the intact limbs of the two groups with femoral head necrosis was significantly less than that in normal group.2) The muscle strength of lateral rotation in the affected limbs in the two groups was significantly less than that in the intact limbs. However, the distribution of the hip joint muscle strength was similar to that of the normal group, although the distribution-in the osteoarthritis group was poor.3) It was suggested that muscle training for all joint muscles, especially extensor muscle strengthening in the prone position, both preoperatively and postoperatively is crucial to maintaining satisfactory joint function.