We studied eighty-two consecutive spherocentric total knee
arthroplasties with an average follow-up of four years (range, two to six
years). All patients had either severe preoperative instability or
deformity, or both. The over-all functional improvement and symptomatic
relief were excellent. Knees with preoperative instability did as well as
those with preoperative deformity that were stable. The knees with
preoperative valgus deformity were the most likely to have postoperative
wound problems or transient nerve palsy, while those with preoperative
varus deformity were much more likely to have loosening. Postoperative limb
alignment of 7 to 9 degrees of valgus angulation protected against lucency
and loosening. No new cases of lucency or loosening appeared after two and
one-half years. The infection rate was 4 per cent and the rate of failure
due to loosening was 5 per cent. The over-all reoperation rate was 9 per
cent. Nine patients (with eleven arthroplasties) died during the follow-up
period.