Polycentric total knee arthroplasty.

Polycentric total knee arthroplasty was first performed by Frank Gunston,2 who designed the polycentric components during his tenure at Wrightington, England, with Sir John Charnley . He presented the early results to the Canadian Orthopaedic Association in 1969, where the report was heard by one of us (L.F.A.P.). The interest aroused by this presentation prompted a visit by the second author (R.S.B.) in December 1969 to Doctor Gunston in Winnipeg to observe the procedure and to examine patients postoperatively. Because the functional results in these patients were better than those we had observed in patients with other types of arthroplasty, immediate enthusiasm was aroused. Doctor Gunston manufactured his own prostheses and agreed to furnish prostheses to us, but later he was unable to do so. With his permission, we developed modified versions of his prostheses in our engineering department, and the first 81 prostheses inserted in patients at the Mayo Clinic were manufactured here. We in-