A computer-aided analysis has been carried out on 176 knee replacements performed on 129 patients during the last 12 years. Owing to the variety of knee replacements used, the number of complications seen, and the large quantity of survey data a computer was very helpful in storing this amount of data with facilities for rapid recall of information. The results of the early Shiers knee hinged arthroplasties have been less than 50% good results, and these were followed by many complications. A smaller number of other knee replacements have been analysed, namely, Freeman-Swanson, Gunston, Sheehan, and Attenborough. The best results were obtained using 60 Attenborough knee prostheses, with a low infection rate of 3.3%, a loosening rate of 5%, and good prospects of salvage by fusion of the knee if required.