Sixty-one polyethylene bearings from an early design of the 'Minns' meniscal knee prosthesis have been retrieved from 32 patients after an average of 55 months in situ. The knee had traumatically dislocated in 22 cases, five polyethylene components had broken (three with evidence of overstressing and fatiguing of the material), two displayed wear patterns caused by cement debris impingement and five showed damage just below the surface due to cyclic fatigue failure caused by overstressing. Two sizes and shapes of polyethylene debris were seen histologically. The larger debris (> 100 μm) were always associated with delamination seen in the dislocated knees, with the worn surfaces showing some evidence of cement beads released during abrasion with the side of the prosthesis. The smaller debris may be associated with adhesive wear of the polyethylene with the cobalt-chrome alloy of the femoral component.