[GUEPAR total elbow prosthesis in rheumatoid arthritis. A multicentric retrospective study of 38 cases with an average 4-year follow-up].

PURPOSE OF THE STUDY: We conducted a multicentric retrospective analysis of outcome after implantation of 38 GUEPAR elbow prostheses in 36 patients with rheumatoid polyarthritis.

MATERIAL AND METHODS: The GUEPAR elbow prosthesis is an anatomic prosthesis developed in 1985 by the Groupe pour l'Utilisation et l'Etude des Prothèses Articulaires (GUEPAR). The recommended surgical technique is described. Patients included in this series had moderate to severe persistent elbow pain. Preoperative motion was 113 degrees flexion with a mean 41 degrees extension deficit. The mean global Mayo Clinic score was 32/100; clinically, the overall assessment was poor in 8 and mediocre in 30. Radiographically there were 16 grade III, 16 grade IV and 4 grade V elbows in the Larsen classification. Two cases were arthroplasty revisions.

RESULTS: All patients were seen at a mean 47.6 months follow-up (12 to 97 months). There were two early failures (1 infection and 1 instability) leading to ablation of the prosthesis. Results were analyzed for the 36 remaining arthroplasties. Total pain relief was achieved in 18 cases with only occasional pain in 17 others. Postoperative motion was 132 degrees flexion with a 30 degrees extension deficit, giving a mean 30 degrees gain. The global Mayo Clinic score was 85/100 with 32 excellent, 3 good and 1 mediocre results. Radiography revealed 2 cases of loosening of the humeral component and 1 bipolar loosening that had not required revision at last follow-up. Prosthetic instability was the most frequent among the early and late complications.

DISCUSSION: Total elbow arthroplasty is a useful therapeutic option among the treatments proposed (including chemical or isotopic synoviothesis, synovectomy, arthroplastic resection) for rheumatoid elbows. It is indicated for Larsen grades III, IV and V and provides good functional outcome and nearly constant pain relief with an amplitude greater than the 100 degrees, generally accepted as functionally useful. In light of our experience we propose certain modifications of the current GUEPAR implant: adjunction of a condylar extension to the humeral component in order to reduce rotation stress and thus avoid humeral loosening and a radial head element to limit the risk of instability.