S3001 THE RHEUMATOID WRIST

Abstract

The wrist is one of the main targets of rheumatoid arthritis. The classic pattern of deformity and destruction shows involvement of the radio-carpal and the radio-ulnar joint with destabilization of the carpus, resulting in a ulnar sliding of the wrist. With ongoing disease a radial tilting and a carpal supination is observed. Although considered as a uniform systemic disease of immunogenetical background the patients show various courses of this disease. The recognition of the pattern of progression may have implications on the management and also on the surgical treatment of the patients. Most currently used classifications of wrist deformity include mainly the actual destruction of the carpal joints but do not include the different possible pattern of progression. For optimal surgical treatment of rheumatoid wrists it seems mandatory to recognize the type of destruction if possible already at early stages of the disease. Based on radiological long-term analysis, Simmen et al. proposed a new classification of rheumatoid wrist involvement considering the type of destruction and possible future development with direct consequences for surgical decisions. Three pattern of destruction are distinguished, based on the morphology of destruction and the course over the duration of the disease. Serial radiographs allow the classification in either type I, II or III wrists. Type I rheumatoid wrists show a spontaneous tendency for ankylosis type II wrists remain stable and show a destruction pattern which resembles osteoarthritic changes and type III wrists show a disintegration with progressive destruction and loss of alignment. Type II is further subtyped in III a with more ligamentous destabilization and type III b shows bony destruction with finally complete loss of the wrist architecture. The classification into the different types of the natural course of the disease at wrist level is based on serial radiographs and measurement of carpal height ratio and ulnar translation. A change in the carpal height ratio of more than 0.015 and/or an increase of ulnar translation of more than 1.5 mm per year classifies a wrist in the type III category. Type I and II wrists have a low probability undergoing radiocarpal dislocation.

Therefore surgical treatment including wrist and tendon synovectomy and usually ulnar head resection, gives satisfactory results also in the long-term. In contrast type III wrists, because of ligamentous and/or bony destruction, require a procedure which provides realignment and stability.