Mobile- versus fixed-bearing unicompartmental knee arthroplasty.

Unicompartmental knee arthroplasty using either a mobile- or fixed-bearing technique is an attractive alternative to osteotomy or total knee arthroplasty in selected patients with osteoarthritis. Both techniques appear to yield equivalent early results. Mobile-bearing articulations have the advantage of allowing a metal-backed component to be used with a composite thickness as thin as 6 mm. They also offer the potential for decreased long-term wear complications because of the high conformity of the articulation. The longevity of fixed-bearing components will likely be improved in the future with better prosthetic designs and improved polyethylene to minimize the incidence of late wear complications.