The Value of Traction During Roentgenography of the Hip

Abstract

Traction on the lower extremity during radiography of the hip usually produces subluxation accompanied by a “vacuum phenomenon” in both normal and abnormal cases. The traction causes spontaneous intra-articular release of gas, and the resultant pneumoarthrogram clearly portrays the articular cartilage. Increased interosseous space without concomitant intra-articular gas is indicative of joint disease with effusion. Its simplicity and apparent reliability make it useful, especially in joints such as the hip in which effusion is difficult to diagnose clinically. It is a potentially valuable technique for radiologic investigation of various hip diseases.