Evaluation of the Effect of Cement Viscosity on Cement Mantle in Total Knee Arthroplasty

Aseptic loosening of the tibial implant remains one of the major reasons of failure in Total Knee Arthroplasty (TKA). The cement viscosity at the time of application to the bone is of great importance to ensure a long-term success of the arthroplasty, as it influences the cement penetration and stability of the prosthesis. Currently, there are number of cements available with a wide range of viscosities and set times. High viscosity faster-setting cements may significantly reduce operating room times. However, the concern is that this positive feature may be at the expense of decreased penetration into the bone, and hence reduced stability of the construct. The use of four cement types ((DePuy II (DePuy Inc. Warsaw, IN), Endurance (DePuy Inc. Warsaw, IN), Simplex-P (Stryker Corp Kalamazoo, MI), and Palacos (Zimmer, Inc, Warsaw, IN)) were compared and evaluated during TKA using surrogate tibiae, with respect to the depth of cement penetration according to the Knee Society Total Knee Arthroplasty Roentgenographic Evaluation System. On radiographic analysis of the implanted surrogate tibiae, it was found that Simplex had the maximum commulative penetration of 19.2 mm in seven zones in Mediolateral view, and 12.7 mm in three zones in anteroposterior view. In zone seven, the difference was statistically significant when comparing Simplex with Palacos (11 mm vs 4.6 mm, two-tailed P value = 0.035), somewhat significant with Depuy 2 (11 mm vs 6 mm, two tailed P value = 0.08), but the different was not significant when compared with Endurance (11 mm vs 10 mm, two-tailed P value = 0.6345). In Zone 5, the difference was statistically significant with Simplex vs Endurance (0.3 mm vs 2.2 mm, P = 0.028), and with Simplex vs Depuy 2 (0.3 mm vs 2.17 mm, P = 0.012). This study enhances the understanding of the relation between cement viscosities and cement penetration into cancellous bone during TKA.