12-Year clinical and radiological results of a double-blind randomized controlled trial comparing posterior cruciate-retaining versus posterior-stabilized total knee arthroplasty

BackgroundA subject of ongoing debate among orthopedic surgeons is the importance of preserving the posterior cruciate ligament in total knee arthroplasty (TKA), but long-term survival studies are scarce. The aim of this study was to compare long-term survival rates, and clinical and radiological follow up of a double-blind randomized controlled trial comparing posterior cruciate-retaining (PCR) versus posterior-stabilizing (PS) implant design of an AGC TKA.MethodsA total of 114 patients were included in the survival analysis (PCR n = 61; PS n = 53). Forty-five patients (PCR n = 25; PS n = 20) participated in the long-term follow up using patient-reported outcome measures (Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short-Form Health Survey (SF-36) and Kujala score (measuring anterior knee pain)). Thirty-one patients were assessed with a physical test (Knee Society Score (KSS)) and radiographs.ResultsOverall survival rate was 95.6% (PCR 98.4% vs. PS 92.5%), with five patients having a major revision (PCR n = 1 vs. PS n = 4, respectively). Satisfying outcome scores for both groups were described at on average 12-year follow up with no significant differences in KSS knee and function scores, WOMAC, SF-36, or Kujala scores between groups. Radiographically, there were no findings of femoral or tibial loosening or polyethylene wear in either group.ConclusionsGood long-term survival rates were described for the PCR and the PS design of an AGC TKA. There were no significant differences in clinical and radiological outcomes between a PCR and a PS design 12 years postoperatively.