Alumina-on-alumina THA in Patients with Juvenile Idiopathic Arthritis: A 5-year Followup Study

Background THA is a concern in juvenile idiopathic arthritis (JIA) owing to patients’ youth, poor bone stock, and small physical size.

Questions/purposes We asked whether (1) uncemented alumina-on-alumina THAs have good clinical and radiographic results at midterm followup in young patients with inflammatory arthritis and end-stage hip disease secondary to JIA, and (2) the anatomic center of rotation of the hip could be reconstructed in patients with acetabular protrusion. We also assessed the rate of surgical complications.

Patients and Methods We retrospectively reviewed 31 alumina-on-alumina THAs in 21 patients with a mean age of 30.9 years (range, 14-48 years). Minimum followup until the time of revision of any component or the latest evaluation was 16 months. For nonrevised cases, the minimum followup was 60 months (range, 60-108 months). Acetabular protrusion was mild in 17 hips (Group 1) and moderate-severe in 14 (Group 2). Bone autograft was used to reconstruct the acetabulum in Group 2. Acetabular reconstruction was evaluated according to Ranawat et al.

Results One cup was revised owing to aseptic loosening at 16 months; the remaining hips showed good clinical and radiographic results. The mean postoperative horizontal distance and the distance between the center of the head of the prosthesis and the true center of the femoral head improved in Group 2. There were no complications related to alumina.

Conclusions Although THA is a technically demanding procedure in patients with JIA, uncemented alumina-on-alumina THA provides pain relief and improves quality of life. In patients with acetabular protrusion, bone grafts enable anatomic cup positioning. Continued followup will be required to determine whether the alumina-on-alumina bearings in patients with JIA result in less osteolysis and loosening.

Level of Evidence Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.