[Involvement of the hip in systemic-onset forms of juvenile chronic arthritis. Retrospective study of 28 cases].

The objective of this work was to evaluate the course of hip disease in patients with systemic-onset juvenile chronic arthritis. 59 patients with systemic-onset juvenile chronic arthritis followed-up for a mean of 15 years (+/- 6 years) were studied retrospectively. 28 patients (47.5%) had involvement of the hip. Mean age at onset of symptoms of hip disease was 9.5 years (+/- 5 years). Hip arthritis was always preceded by other manifestations of the disease, including arthritis of other lower limb joints. Mean time interval between onset of the disease and onset of hip symptoms was 6.3 years (+/- 3 years). In 66% of cases, symptoms occurred simultaneously in both hips. Eight of nine patients with initially unilateral hip arthritis subsequently developed arthritis of the other hip; in four patients, less than one year elapsed between involvement of the two hips. Roentgenographic changes were variable and included acetabular protrusion (25%), complex cervico-cephalic and acetabular growth disorders (21%), subdislocation (18%), a short femoral neck with varus deformity (14%), and a long femoral neck with valgus deformity (14%). Avascular necrosis of the femoral head occurred in three patients. Roentgenographic evidence of repair was seen in one patient. Among the ten patients who required surgery, two had corrective osteotomy with adductor tenotomy and eight had total hip arthroplasty (of both hips in six patients) with good short- and medium-term outcomes. After arthroplasty, a single patient required reoperation in the short term, for persistent flexion contracture. Loosening of the acetabular arthroplasty required revision in two patients 5 and 10 years, respectively, after the initial procedure.(ABSTRACT TRUNCATED AT 250 WORDS)