[Flexion contracture in haemophilic knee arthropathy--10-year follow-up after hamstring release and dorsal capsulotomy].

INTRODUCTION: The aim of this study was to evaluate the long term results of joint preserving surgery with hamstring release and dorsal capsulotomy for the treatment of therapy resistant knee flexion contracture in patients with severe haemophilia.

METHODS: 16 patients having undergone hamstring release and dorsal capsulotomy were prospectively observed and clinically evaluated over a period of at least 10 years. Follow-up was on average 16.6 (10-26) years. The average age at the time of surgery was 29.4 (15-40) years and at the last follow-up 43.0 (29-65) years. Clinical assessment of the patients was performed at least twice per year and outcome was evaluated by using the Score of the Orthopaedic Advisory Committee of the World Federation of Haemophilia (WFH).

RESULTS: The preoperative extension deficit of 21.1+/-1.82 degrees (10-40 degrees) was improved to 16+/-3.6 degrees (5-30 degrees; p=0.54) at the last follow-up. In the first 4 years after surgery there was a noticeable and continuous improvement of the preoperative extension deficit. The clinical score improved from 7.6+/-0.4 preoperatively to 3.8+/-0.4 one year after surgery. 14 years after surgery a significant difference to preoperative values was no longer evident for the remaining 10 patients. The first 4 years after surgery average range of movement (ROM) improved, yet these differences were not statistically significant. Based on the clinical outcomes as described by Rodriguez-Merchan, last follow-up showed one patient with a good, 11 patients with a moderate and 4 patients with a poor postoperative result. The Petterson score showed a marked and significant deterioration from 7 (5-10) to 9 (7-12) points at final follow-up.

DISCUSSION: The joint preserving method of hamstring release and dorsal capsulotomy for the treatment of therapy resistant knee flexion contracture in patients with severe hemophilia does not prevent the progression of haemophilic arthropathy. Despite this, improvement of the flexion contracture leads to a better joint function over a number of years postoperatively. Especially for the younger patient suffering from manifest haemarthropathic changes of the knee joint, this management option is a feasible alternative to at least postpone joint replacement.