The effect of cement viscosity in total knee arthroplasty

Abstract

Aseptic loosening of the tibial implant remains one of the major reasons of failure in Total Knee Arthroplasty (TKA). Currently, there is no consensus on the role that cement viscosity at the time of application to the bone plays in ensuring the long-term success of the arthroplasty. The purpose of this study was to investigate the relationship between cement viscosity and aseptic loosening of tibial implants. Three cements (Depuy 2, Palacos R (high viscosity cements) and Simplex-P, a medium viscosity cement) were compared during TKA through radiographic analysis and mechanical loading tests using surrogate tibia. Cement penetration was measured from radiographs of the constructs and analyzed according to the Knee Society Total Knee Arthroplasty Roentgenographic Evaluation System. Simplex-P had the maximum cumulative penetration in seven zones in the mediolateral view, and three zones in antero-posterior view. Simplex exhibited maximum penetration in zone 7 in the antero-posterior view, and in zone 3 in the lateral view. For the mechanical tests the TKA constructs were subjected to cyclic compressive loading in the sagittal plane. Simplex-P had the smallest micro-motion in sagittal plane, the results were significant when compared to Palacos R. The consistently superior performance of Simplex-P suggests that cement viscosity does indeed play a role in arthroplasty success. These results have direct clinical relevance for TKA patients suffering from aseptic loosening.