The diagnosis of capsular retraction of the hip is based on measuremen
t 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 vi
sible 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. T
he 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 ch
ondromatosis 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 wi
th 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 barbitur
ate abuse. It is subacute and resolves within several months to two ye
ars. Fluoroscopic intra- articular injection of corticosteroids, repea
ted as required by pain, constitutes the best treatment.