This paper summarises our experience of twenty one patients with degenerative arthritis treated by bilateral simultaneous total knee replacement (BSTKR) in Tawakal Hospital in a period of twenty two months vis. January 1994 to November 1995. The results were analysed according to the scoring system of Hospital for Special Surgery. The preliminary observations were encouraging, 90% excellent, 8% good and 2% fair results. The benefits, safety and cost effectiveness of the procedure as compared to the unilateral staged knee replacement are discussed. We recommend that BSTKR be routinely practised for appropriate situations in all institutions where the expertise and facilities are available.
The total replacement of wrists affected by rheumatoid arthritis (RA) has had mixed outcomes in terms of failure rates. This study was therefore conducted to analyse the biomechanics of wrist arthroplasty using recently reported implants that have shown encouraging results with the aim of providing some insights for the future development of wrist implants. A model of a healthy wrist was developed using computed tomography images from a healthy volunteer. An RA model was simulated based on all ten general characteristics of the disease. The ReMotion ™ total wrist system was then modelled to simulate total wrist arthroplasty (TWA). Finite element analysis was performed with loads simulating the static hand grip action. The results show that the RA model produced distorted patterns of stress distribution with tenfold higher contact pressure than the healthy model. For the TWA model, contact pressure was found to be approximately fivefold lower than the RA model. Compared to the healthy model, significant improvements were observed for the TWA model with minor variations in the stress distribution. In conclusion, the modelled TWA reduced contact pressure between bones but did not restore the stress distribution to the normal healthy condition.