The effect of a tibial baseplate undersurface peripheral lip on cement penetration in total knee arthroplasty

Many total knee arthroplasty (TKA) tibial baseplates have a peripheral lip or cement pecker theoretically to increase cement penetration by decreasing edge escape of the cement squeeze film on baseplate impaction. We reviewed 177 consecutive TKAs (89 nonlipped and 87 lipped baseplates) performed by a single surgeon, using the same third-generation tibial cementation techni ques. Cement penetration patterns of the lateral 12 mm of proximal tibia we re examined by a semiautomatic computerized digital image analysis techniqu e. Penetration in the lipped baseplate was double that of the nonlipped bas eplate at the component's lateral edge (P < .05) and continued to be statis tically significantly greater to 4 mm from edge. From 5 to 7 mm, the differ ence was no longer statistically significant, and from 8 to 12 mm, the pene tration was equal.