Contribution of Surface Polishing and Sterilization Method to Backside Wear in Total Knee Arthroplasty

The purpose of this study was to compare the relative contributions of backside wear from polished and roughened tibial baseplates and different sterilization methods. Three groups of tibial inserts of the same design were matched: roughened gamma-air (RGA), polished gamma-air (PGA), and polished gas-plasma (PGP). Visual damage scoring and micro-CT deviation maps were used for evaluation. Total backside damage was higher (P = 0.045) in RGA (13.8 ± 3.4) compared to PGA (8.7 ± 3.4) and PGP (8.2 ± 4.8). Backside wear rates were greatest (P = 0.02) in RGA (0.038 mm/year), followed by PGA (0.012 mm/year), and lowest in PGP (0.009 mm/year). Use of a roughened tibial baseplate had a greater effect on wear magnitude than sterilization method.