Superior One-year Forgotten Joint Scores with cruciate-retaining mobile bearings versus posterior-stabilized mobile and fixed bearings in a contemporary total knee system.

BACKGROUND

Total knee arthroplasty (TKA) mainly involves the femoral, tibial, and bearing implants. Bearings are categorized by posterior cruciate ligament (PCL) status (cruciate-retaining [CR] vs. posterior-stabilized [PS]) and motion (mobile vs. fixed). This study assessed the impact of three bearing combinations (CR Mobile, PS Mobile, and PS Fixed) on one-year patient-reported outcome measures (PROMs) following TKA.

METHODS

In this retrospective analysis of 486 TKAs using the same prosthesis with varied bearings, patients were grouped as CR Mobile, PS Mobile, and PS Fixed. Patient characteristics, preoperative, and one-year postoperative PROMs (Forgotten Joint Scores [FJS] and Knee Society Scores [KSS], and Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), were collected. Multivariate analysis was conducted to assess the impact of bearing type on one-year PROMs.

RESULTS

The multivariate regression model showed that bearing type significantly impacted the one-year FJS, with CR Mobile showing higher scores than PS Mobile and PS Fixed bearings (p < 0.001). However, bearing type did not significantly influence one-year KSS and WOMAC scores (all p > 0.05).

CONCLUSION

This study was the first to analyze the impact of the combination of PCL status and bearing motion in TKA. Bearing type selection had an impact on the one-year postoperative FJS, particularly favoring CR Mobile bearings. Other PROMs were not affected by the choice of bearing type.