Abstract
Introduction
Previous studies comparing cruciate retaining (CR) and cruciate sacrificing - posterior stabilised (PS) TKRs have failed to demonstrate a difference in outcomes based on numbers of patients recruited.
This large study compares clinical outcomes in groups having PS and CR TKR and reports the results at 1 and 2 years post-operatively.
Methods
A total of 683 patients undergoing TKR were consecutively enrolled in a prospective multi-centre study with 2 arms. In the first arm patients receiving a PS component were randomised to receive either a mobile bearing (176 patients) or fixed bearing (176 patients) implant. In the second arm, patients receiving a CR component were randomised to receive either a mobile bearing (161 patients) or fixed bearing (170 patients) implant. All patients were assessed preoperatively and at one and two years postoperatively using standard tools (Oxford, AKSS, Patellar Score) by independent nurse specialists. The data from the 2 arms of the trial were then analysed to compare differences between PS and CR implants.
Results
Patients with a PS component showed a greater improvement in the pain component of the AKSS at 1 year (p=0.0003) and at 2 years (p=0.0085) post-op.
Patients with a PS also showed a greater improvement in the AKSS knee score at 1 (p=0.0001) and 2 (p=0.001) years.
Range of motion (ROM) improvement was also greater in the PS group at 1 (p=0.0001) and 2 (p=0.0170) years.
PS knees also achieved better outcomes in these variables in both mobile and fixed subgroups.
There were no other significant differences in the scores between the two groups at any stage.
Conclusion
Improvements in pain and knee components of the AKSS score and ROM at both 1 and 2 years follow-up were greater in PS knees. Although this difference was statistically significant, differences in real terms were relatively small.
