Background: There is a lack of data on the functional effect of open hip synovectomy in a large number of patients with juvenile rheumatoid arthritis evaluated with a validated assessment tool.

Methods: Between 1985 and 1997, sixty-seven open hip-joint synovectomies were carried out in fifty-six patients with juvenile rheumatoid arthritis. Fifty-five hips (82%) had radiographic changes that were stage III or higher according to the system of Larsen et al. Hip function was evaluated preoperatively and after a mean of fifty months with the Merle d'Aubigné hip score.

Results: Sixty-five (97%) of the sixty-seven hips were available for follow-up. The mean total Merle d'Aubigné hip score (and standard error of the mean) was significantly improved from 9.5 ± 2.5 points at baseline to 16.3 ± 1.0 points at the time of follow-up (p < 0.001). The individual scores for pain, mobility, and walking ability were significantly increased as well (all p < 0.001). Eighty-five percent of the hips were observed to have a very great or great improvement in function. A concomitant soft-tissue release was performed in seven hips, and nine hips required surgical dislocation. Surgical complications included two superficial wound hematomas that did not require intervention; osteonecrosis of the femoral head was not observed. Five hips required total hip arthroplasty during the follow-up period. Thus, the survival rate for the hips was 94% at a mean of four years following the synovectomy.

Conclusions: Open hip synovectomy in patients with juvenile rheumatoid arthritis is a safe procedure that can improve hip-joint function for up to five years.

Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.