In rheumatoid arthritis (RA), non constrained or semi-constrained prostheses can be used. The authors used the Kudo III, IV or V or iBP prostheses 54 times from 1994 to 2003. After initial satisfactory results, they had to change one or both implants for several reasons: humeral stem fracture (5 cases), unipolar humeral loosening (1 case), ulnar loosening without laxity (8 cases), polyethylene wear (11 cases), due to progressive ulnar collateral ligament lengthening and progressive valgus deformity, without or with metallosis, due to contact between Cr-Co humeral component and titanium alloy ulnar component, chronic infection (1 case). When the local conditions were satisfactory (bone stock, ligament balance), the fractured or loosened component was changed. When the conditions were bad (poor bone stock, ligament misbalance, metallosis), both implants were removed; posterior humeral and/or medial or lateral ulnar window were used to removed the uncemented stems still osteointegrated. All the bipolar operations used the Coonrad-Morrey prosthesis, but the last case a Discovery prosthesis. The operative tricks are described, the management of the extensor apparatus is discussed, the clinical outcomes (especially the extensor apparatus function, most often weak) and the radiographic outcomes are presented

We undertook a radiological analysis of 186 standard Souter implants to determine survivorship and to analyse the pattern of failure in those needing revision. The implants had been inserted as a primary procedure in patients with rheumatoid arthritis of the elbow at our hospital over the last 12 years. Taking revision as an endpoint, the survivorship after 12 years was 87%. If, however, revision and loosening, defined as the Hindex value equivalent to demarcation of 1 mm around the whole implant, are also included, the survivorship falls to 80%. Of the 24 implants revised, 18 (75%) were for problems with the humeral component, three (12.5%) with the ulnar component and three (12.5%) for instability. Loosening of the humeral component occurred when the implant extended into the humerus, with the tip moving anteriorly on to the anterior humeral cortex. Our study indicates that loosening can be predicted by the rate of change in this angle of extension of the prosthesis