Hip joint ultrasonography: correlation with intra-articular effusion and synovitis.

The ultrasonographic distance between the collum of the femur and the capsule of the hip joint was measured in 88 hips of 75 patients with chronic inflammatory joint disease and with hip joint symptoms or signs. In addition, 10 other hips were measured before soft tissue operation of the hip joint. The ultrasonographic distance was 7 mm or more in 29 out of 33 hips with synovial fluid in joint puncture and in seven out of nine hips with intra-articular effusion or synovitis in open surgery. Intra-articular injection of corticosteroid resulted in a significant decrease in the enlarged ultrasonographic distance, in joints both with and without synovial fluid. Joints not treated with steroid did not show any change. It is concluded that both joint effusion and synovitis without effusion can increase the anechogenic distance between the bone and the joint capsule.