Premature failure of the polyethylene tibial bearing surface of the Interax knee arthroplasty.

Thirty-four patients (37 knees) were treated with the Interax knee arthroplasty. There were 31 female and 3 male patients with a mean age at surgery of 70 years (range, 53-84 years). Premature failure of the polyethylene tibial bearing surface occurred in 9 patients (9 knees). Eight patients of these required a revision operation because of early wearing out of the tibial surface 20 to 38 months after the operation. The failure was due to inadequate implant design in small component and polyethylene gamma irradiated in the air.