INTRACAPSULAR PRESSURE AND PAIN IN COXARTHROSIS

Intracapsular hip pressure was measured before surgery in 17 patients (18 hips) with coxarthrosis. The results were correlated to pain as re gistered on a visual analog scale. With the hip in extension, the pres sure was 49.5 mmHg (SD, 40.2); in 45 degrees of flexion, it was 21.3 m mHg (SD, 14.6); in extension and inward rotation, it was 105.7 mmHg (S D, 76.0); and in extension and outward rotation, it was 40.8 mmHg (SD, 32.0). A small amount, 0.7 mt (SD, 1.14), of joint fluid was aspirate d following pressure registration. Pressure correlated significantly t o pain at night, when starting to walk, and on walking. It is suggeste d that the increase in intracapsular hip pressure is a cause of pain i n coxarthrosis, with subsequent limitation of movement and joint contr acture.