The spherocentric knee prosthesis (long term results in 18 cases).

The authors report the clinical and radiographic results at from six months to two years after the insertion of spherocentric knee prostheses in fourteen patients with rheumatoid arthritis and four patients with arthrosis of the knee. The results were satisfactory and there were no complications. This type of prosthesis has therefore become the treatment of choice in cases of varus or valgus deformity in excess of 30 degrees and those involving extreme instability. It is also an alternative after failures with other types of prosthesis.