[Limitations of replacing the semilunar with a Swanson's implant]

Nineteen patients have had an arthroplasty of the semilunar by Swanson's prosthesis at stage III of Kienbock's disease. They have been reviewed after an average period of 4 years. The clinical evaluation finds 14 good and excellent results, two fair and 3 poor ones. Its analysis shows a persistence of a non limiting pain 15 times; a fair muscular strength which reaches 65 per cent of the strength of the healthy side and articular amplitudes reduced by 36 per cent of the normal amplitude. Radiologically, the study of the wrist as a whole shows that the prosthetic implantation avoids the aggravation of the collapse of the wrist, whereas its cubital sliding increases by about 15 per cent. The analysis of the evolutive mode of the wrist shows a subluxation of the scaphoid which leads 15 times to a scaphoradial arthrosis; 17 times were observed lytic signs which in 4 cases have evoked a synovitis. It seems therefore that the clinical results are favourable more than 3 times out of 4, but radiological signs of osteoarticular degeneration show the necessity to stabilize the external column of the wrist, in order to avoid the deterioration of the Swanson's implants.