Comparison of cruciate sacrificing and cruciate retaining PFC sigma TKR—minimum 2-year follow-up

Abstract

Introduction

Excellent clinical results have been reported with both cruciate sacrificing; posteriorly stabilised (PS) and cruciate retaining (CR) total knee replacement designs. This study compares clinical outcomes in groups having PS and CR total knee arthroplasty in a large series at 2 years follow-up.

Methods

A total of 683 patients were consecutively enrolled in a prospective multi-centre study with two arms. In the first arm, patients received a PS component and were randomised to receive either a mobile or fixed bearing implant. In the second arm, patients receiving a CR component were similarly randomised. All patients were assessed using standard tools (Oxford Knee Score (OKS), American Knee Society Score (AKSS), 12-Item Short Form Health Survey (SF-12)). As this was a large study with multiple variables analysed, a Bonferroni adjustment was carried out and the level of statistical significance was taken as P < 0.001.

Results

There was no difference between arm 1 and arm 2 in the change in range of motion, OKS, SF-12 or AKSS function scores. The only statistically significant change was an improvement in range of motion in the PS design in stiff knees (a pre-operative range of motion of less than 90 °).

Discussion

This study reports on a large prospective multi-centre series of PS and CR total knee replacements (TKRs). The only statistically significant difference was found in patients with stiff knees pre-operatively who had a significant improvement in the range of motion with the use of a PS design compared with the CR.