Intermediate term evaluation of the Eclypse distal radio-ulnar prosthesis for rheumatoid arthritis. A report of five cases.

Hypothesis: Early medical management of rheumatoid arthritis with biotherapy has changed the traditional musculoskeletal damage from this disease. When the distal radio-ulnar joint (DRUJ) is involved, classic procedures may be inappropriate. We chose a hemi-arthroplasty of the DRUJ joint (Eclypse™) in patients with persistent synovitis and chondrolysis with a stable joint. The aim of this study was to assess the intermediate term results of this approach in these specific cases.

Materials And Methods: We report a retrospective study of 5 Eclypse arthropasties implanted between March 2005 and March 2011. There were 4 women and 1 man, mean age: 58.4years old (54-62) with RA that had been present for 21.6years (15-33). This hemi-arthroplasty replaced the ulnar head with a pyrocarbon component. Patients were evaluated by an independent observer for pain by VAS, range of motion, grip strength in the neutral position by Jamar dynamometer, pronation and supination strengths with a pronosupinator, DASH score and wrist X-rays.

Results: One patient was lost to follow-up and the 4 others underwent a follow-up evaluation at 64 months (43-90). There were no intra-operative or postoperative complications. The pain score at the final follow-up was 1.5/10 (0-4), pronation was 70° (60-80) and supination was 80° (80-80). Grip strength was 148% compared to the contralateral side (73-200%). Pronation and supination strengths were 1.7kg (1.5-2) and 2.1kg (2-2.5) respectively. The DASH score was 55.9 points (42.6 to 79.3). X-rays did not show any changes in the ulnar notch.

Conclusion: This distal radio-ulnar arthroplasty is less invasive and preserves the bone and ligaments. Clinical results are rapid, remain stable over time and are well tolerated. This arthroplasty, which was initially developed for osteoarthritis and traumatic lesions of the DRUJ, is promising for specific cases of rheumatoid arthritis.