After review of the first 209 polycentric total knee arthroplasties (in
159 patients) performed at the Mayo Clinic between July 1970 and November
1971, we found that the calculated probability of the arthroplasty
remaining successful ten years postoperatively was 66 per cent. Actual
results showed 42 per cent of the arthroplasties to be successful in
patients who were still alive at review; another 24 per cent were
successful but were in patients who had died or were lost to follow-up
before ten years postoperatively. In 34 per cent failure occurred, which we
defined as reoperation for any reason, unacceptable pain, or loss of
function. The most common causes of failure were instability or ligament
laxity (13 per cent), loosening of a component (7 per cent), infection (3
per cent), and patellofemoral joint pain (4 per cent). Prior knee surgery
significantly decreased the probability of success, as did axial
malalignment of the prosthetic components at operation.