Summary

This randomized controlled trial evaluating outcomes 5 years after TKA using either PS or BCR prostheses showed equivalent patient-reported outcomes in both groups at the last follow-up but an overall implant survivorship superior in the PS group.

Abstract

Background

High rates of chronic pain and dissatisfaction are still being reported following total knee arthroplasty (TKA). Bicruciate retaining (BCR) prostheses have been identified as one promising avenue to improve patient satisfaction by optimizing the restoration of normal knee kinematics. The purpose of this prospective was to investigate whether BCR prostheses provide better clinical and radiologic outcomes compared to traditional posterior-stabilized (PS) prostheses.

Material And Methods

This single-blind randomized controlled trial enrolled a total of 79 patients (96 knees) who underwent TKA between 2011 and 2019. Eligible patients were randomized intra-operatively and followed for 5 years. Radiologic, clinical and patient-reported outcomes were recorded at each follow-up. KOOS, WOMAC and IKS scores (old version) were analyzed and compared between groups. Statistical analyses were performed using Chi2 test, student t-test and Kaplan-Meier.

Results

A total of 60 patients (77 knees) were randomized, with 38 knees and 39 knees assigned in the PS and BCR groups respectively. No statistically significant differences were noted in KOOS, WOMAC or SF-12 scores within the 5 years of observation. At 6 weeks, 6 months and 12 months, knee flexion was significantly higher in the PS group compared to BCR group (p=0.002). At 5 years, the overall implant survivorship was 87.2% in the BCR group compared to 100% in the PS group (p=0.053).

Discussion And Conclusion

PS and BCR prostheses were associated with similar clinical and patient-reported outcomes. Despite superior flexion in the PS group, both techniques yielded equivalent improvements of pain, function and range of motion at 5 years. Further research is warranted to determine whether or not BCR prostheses can yield significant advantages compared to other designs on the market.

Level of evidence: I. Randomized control trial.

Keywords: Total knee arthroplasty, bicruciate-retaining, posterior-stabilized, knee,