The results of modified distraction arthroplasty for degenerated osteoarthritis of the ankle

Abstract

Purpose: In the treatment of degenerated osteoarthritis of the ankle, we obtained good results in terms of preserving the joint functions and relieving pain by performing a procedure to reconstruct the anatomical structure of the ankle, accompanied by ROM exercises undertaken with the joint space kept pulled apart with a conventionally used external fixator. Methods: A total of 43 patients (45 ankles; 28 ankles in 28 male patients and 17 ankles in 15 female patients) who underwent the procedure from 1998 to 2012 were enrolled in the study. The patients were 18-72 years old, with a mean age of 56 years at the time of the procedure. In regard toTakakura’s classification, 6 ankles were classified as Stage 2, 21 as Stage 3a, 12 as Stage 3b, and 6 as Stage 4. The patients underwent debridement by the conventional method, including removal of bone spurs and synovectomy, combined with low tibial osteotomy, osteochondral graft, drilling and/or reconstruction of ankle lateral ligaments. As post-treatment, patients were started on active ROM exercises from the day after the surgery and started partial weight bearing at 6-8 weeks after the surgery. The external fixation device was removed to allow total weight bearing at 3 months. Follow-ups were performed for 1-8 years, with a mean of 4 years and 7 months. Results: The pain severity did not change in 2 ankles. For the remaining 43 ankles in which the pain improved, no problems in daily life activities, but inability to undertake sports activities were observed for 31 ankles, while no problems in either physical work or sporting activities for 12 ankles. None of the patients took painkiller. Improvements of the ROMwere seen in 10 ankles, while no change of the ROMwas observed in the remaining 35 ankles. There were no patients who needed additional operations such as arthrodesis during the follow-up period. Conclusions: Procedures such as arthrodesis, total ankle replacement and low tibial osteotomy are performed to treat degenerated osteoarthritis of the ankle, but each of these is associated with problems, including those related to the qualifying age, durability, and range of motion. It is difficult to select a proper treatment option, especially for relatively young patients. In contrast, there is no age requirement for the procedure described in this study, because joint functions are preserved by restoring the patients’ own tissue and the patients suffered only mild postoperative limitation of the ADL. As demerits, this procedure is less effective for pain relief than arthrodesis and more abundant experience is required, because several kinds of surgical procedures have to be performed. However, it can be indicated for young patients in whom preservation of the joint functions and higher activity potential are required. In addition it is well applicable to degenerated osteoarthritis of the ankle that arises at a relatively early age, because future joint replacement or arthrodesis will not be difficult in patients who undergo this procedure.