[Capsular retraction of the hip].

The diagnosis of capsular retraction of the hip is based on measurement of the capacity of the joint cavity on arthrography: it is reduced by at least 25% (normally 15 ml +/- 2 ml). The opaque area is only visible reduced in the more severe forms with a capacity of 5 ml or less. The arthrographic image is therefore not the key to the diagnosis. The major clinical sign is restriction of joint movement, especially in abduction and rotation. Secondary, "surgical" capsular retraction of the hip is the most common form. It is associated with synovial chondromatosis in more than one half of cases. The mean capacity is 6.8 ml (range: 0 to 12 ml). Irreducible flexion deformity and limitation of movement are of variable severity. Capsulectomy must be combined with joint debridement (systematically including the depth of the socket). "Medical" capsular retraction of the hip is the rarest form. It may be either idiopathic or secondary to diabetes or chronic barbiturate abuse. It is subacute and resolves within several months to two years. Fluoroscopic intra-articular injection of corticosteroids, repeated as required by pain, constitutes the best treatment.