Abstract
Introduction
When introducing new joint replacement designs, it is difficult to predict with any certainty the clinical performance of the new designs. Using roentgen stereophotogrammetric analysis (RSA) to evaluate the first two years of follow-up can serve as a predictor of late mechanical loosening for hip and knee prostheses. This prospectively randomized study was designed to evaluate the clinical performance of the Triathlon total knee system and compare the results between the two versions; posterior stabilized (PS) and cruciate retaining (CR).
Methods
Sixty patients were consecutively randomized (two patients left the study prior to surgery) to receive either the Triathlon total knee PS (30 patients) or the Triathlon total knee CR (28 patients). All components were cemented. The study was approved by the Ethical Committee for Lund University. All patients met the inclusion criteria. There were no statistically significant differences between the demographics for PS and CR. RSA was set to be the principal evaluation parameter. Patient outcome was assessed by the KSS and KOOS questionnaires.
Results
There were no statistically significant differences in rotation or translation around or along the three coordinal axes. Neither were there any differences in the maximal total point motion (MTPM) during the 2-year follow-up (p<0.05).
There were no statistically significant differences between the clinical results of both groups when using the KSS and the KOOS scoring system (p<0.05).
Discussion
There were no clinically significant differences in the RSA 2-year follow-up data, nor in the clinical scores of KSS and KOOS. The results of this study suggest that there is no major differences between the posterior stabilized system and the cruciate retaining system for the Triathlon total knee neither in clinical nor in predictable long term mechanical performance.
