Medial screws and cement: a possible mechanical augmentation in total knee arthroplasty.

The purpose of this study was to determine whether screws placed beneath the medial tibial plateau in cemented total knee arthroplasty helps prevent collapse of the medial tibia. A previous study found that the AGC all-polyethylene tibial component had a 14% rate of collapse of the medial subchondral region in the first postoperative year. Of 536 implanted AGC all-polyethylene tibial components, 20 had screws inserted beneath the medial tibial plateau. No AGC all-polyethylene tibial components with screws failed because of aseptic loosening or collapse of the medial tibial plateau. The study included 125 cemented metal-backed total knee arthroplasties with screws inserted beneath the medial tibial plateau. We also found 2 cases of collapse of the medial tibial plateau and 1 case of collapse on the lateral side. No revisions were performed. The placement of screws beneath the medial tibial plateau to fill large defects is an excellent precaution against collapse of the medial tibia.