Prostheses for joints including flexural elements

Abstract

Replacement of joints in the hand poses certain problems because of the fine movements demanded by the fingers. Unlike the requirements at other sites, artificial finger joints are used to restore function, rather than to get rid of pain or deformity. We now have three types of joint but none is entirely satisfactory; there are also other methods of management for the hand with rheumatoid arthritis, such as synovectomy, arthrodesis and simple spacers which may provide equal benefit to the patient. The problem is one of selection and measurement. It is now possible to measure the power of individual fingers before and after joint replacement (using a cybernometer) and to monitor the recovery of function; it is also possible to estimate the remineralization of bones which so often accompanies such improvement (by using a t. v. colour image analyser).