Purpose: The purpose of this study was to compare the outcomes of cruciate retaining (CR) and cruciate sacrificing (CS) total knee arthroplasty (TKA) in a multi-center randomized clinical trial with greater than 5 year follow-up.
Methods: One hundred and eighty five patients (189 knees) participated in a double-blinded randomized clinical trial. 96 cruciate retaining and 93 cruciate sacrificing total knee arthroplasties (Genesis II, Smith &
Nephew, Memphis, TN) were performed between 1997 and 2000. All surgical procedures were performed by twelve surgeons at twelve medical centers. The average follow-up was 5.8 (5.0–7.3) years. Clinical outcomes (Knee Society Clinical Rating, WOMAC, SF-12, Radiographic Findings) were evaluated preoperatively and at the latest follow-up. Postoperative complications were also examined.
Results: There were no significant differences when comparing cruciate retaining knees to cruciate sacrificing knees in patient demographics and preoperative clinical evaluation. At the latest follow-up, clinical outcomes (CR versus CS) were as follows: Knee Society Clinical Rating (163±26 versus 165±29), knee flexion (114±11&
#12539;versus 118±10&
#12539; p<
0.05), WOMAC (12±7 versus 8±6, p<
0.05), and SF-12 (mental: 52±9 versus 58±4, physical: 41±11 versus 42±10). Radiographic outcomes showed there were no differences in radiolucent lines or loosening, and postoperative complication rate was also not significantly different.
Conclusions: In this randomized clinical trial, both posterior cruciate preserving (CR) and sacrificing (CS) total knee replacements offer excellent clinical outcomes at five or more years follow-up, with the cruciate sacrificing implant studied demonstrating small, but significant improvements in both range of motion, WOMAC, and disease specific outcomes.