We researched into the classification of X-ray figure and the functional evaluation of hip joints according to Japan Orthopaedic Association. Therefore, we examined the isometric muscle strength of hip abductors, the ratio of its strength to body weight and the quantity of employment for hip abductors in 50 cases which contained 100 cases of the bilateral osteoarthritis of hip joints.
Results:
(1) In relations between the age and the classification of X-ray figures in A group, the unilateral type was III. 1, the contralateral type was III. 4 and the average age was 32.2 years old. In B group, the unilateral type was II, the contralateral type was II. 3 and the average age was 37.9 years old. In C group, the unilateral type was I, the contralateral type was I. 6 and the average age was 49.7 years old. In D group, the unilateral type was O, the contralateral type was I. 4 and the average age was 54.9 years old. According as increases of age, the degeneration of regions in X-ray figures was recognized.
(2) In relations between the classification of X-ray figure and the functional evaluation of hip joints in III. 1 type, the average point of the functional evaluation was 86.1. In II type, it was 82.7 and in I type, it was 53.7 and in O type, it was 50.8.
(3) In relations between the classification of X-ray figures and the strength of hip abductors in III. 1 type, the average of the muscle strength was 137.8 kg. In II type, it was 82.7 kg. In I type, it was 53.7 kg and in O type, 50.8 kg.
(4) In relations between the classification of X-ray figures and the ratio of its strength to body weight in III. 1 type, the ratio was 2.7. In II type, it was 1.66. In I type, it was 1.0 and in O type, it was 0.96.
(5) In relations between the classification of X-ray figures and the quantity of employment for hip abductors in III. 1 type, the quantity was 131.7 kg/mm/sec. In II type, it was 79.7 kg/mm/sec. In I type, it was 50.46 kg/mm/sec. and in O type, it was 48.3 kg/mm/sec.
In results of (2), (3), (4) and (5), there was recognized correlation P<0.05 in each reference.
