RESULTS OF THE DUROM-CUP SURFACE REPLACEMENT OF THE HUMERAL HEAD IN RHEUMATOID ARTHRITIS: A PROSPECTIVE ANALYSIS

Abstract

Introduction: Rheumatoid arthritis often leads to severe destruction of the glenohumeral joint including synovitis and inflammation induced alterations of the rotator cuff. Cup arthroplasty, or surface replacement of the shoulder was introduced in the 1980s. The aim of this study was to confirm or withdraw the very promising results of the DUROM-Cup surface replacement for patients with rheumatoid arthritis.

Patients an Methods: From 1997 to 2000 a cohort of 42 DUROM-Cup hemiprotheses were implanted in 35 patients. The patients were evaluated preoperatively and after 3,12 and more than 60 month postoperatively. 7 patients were lost to follow up. A total of 35 DUROM-Cups (29 patients) could be examined prospectively after an average follow up period of 73.1 (+/− 12.1) month (Average age 61.4y, female n=21, male n=68). Rotator cuff defects were classified intraoperatively.

Results: Three revisions occured: One due to a too large implant, one due to glenoid erosion and one due to loosening of the implant. The constant score increased from preoperatively 20.8 points to 64.3 points at a mean follow up of 73.1 month. No differences were seen in patients with massive cuff tears. In these cases the cup was implanted in a more valgic position, so that articulation with the acromion could be achieved. The radiographic results did not show any changing of the parameters for the position of the cup. No further endo-prosthetic loosening was observed. The proximal migration increased in 66% and the glenoid depht increased in 37% of the cups.

Discussion: The results of the cemented DUROM-Cup surface replacement for patients with advanced rheumatoid arthritis of the shoulder are very encouraging, especially in patients with massive tearing of the rotator cuff. The advantages of cup arthroplasty are to be found in the reduced level of invasive surgery and the simpler technique with bone saving fixation. In the event of failure of the implant good further treatment options for salvage procedures remain.