66 – POSTERIOR CRUCIATE PRESERVING VERSUS SACRIFICING TKRS: IS THERE A DIFFERENCE GREATER THAN 10 YEARS FOLLOW-UP?

Abstract

Purpose: There is no consensus whether the posterior cruciate ligament (PCL)should be preserved (CR) or sacrificed (CS) during primary total knee replacement (TKR). The purpose of this study was to compare the greater than 10 year survivorship and health related outcomes of CR and CS TKRs using a single implant system.

Method: Between 1996 and 2000, 478 Genesis II Primary TKRs were inserted in 414 patients. Excluding those with a primary diagnosis other than osteoarthritis, body mass index greater then 40, history of prior patellectomy, fusion or osteotomy, 358 cases in 310 patients were included. 134 (37%) had a PCL preserving (CR) and 224 (63%) had a PCL sacrificing implant (CS). The two patient cohorts were compared for Kaplan-Meier survivorship, health-related outcomes (Knee Society scores, WOMAC, SF-12), range of motion (ROM) and radiographic loosening or wear.

Results: Mean follow-up was 11.87±1.04 years for CR and 10.96±0.87 years for CS (p=0.001). Four cases were revised for infection. No significant differences were noted between the CR and CS Genesis II cohorts at 10 year Kaplan-Meier survivorship excluding infections (CR 0.984±0.011, CS 0.986±0.008, p=0.30). Overall revisions were two for CR (1.5%, no infections) and seven for CS (1.7%, four for infection; 1.3% excluding infections). Revision rates were not significantly different between groups including or excluding infections (p=0.493 and p=1.00 respectively). CS had significantly greater postoperative ROM than CR (CS=114.20±13.60, CR=111.35±12.38, p=0.024). At 10 years, no differences were observed in satisfaction, health-related outcomes or radiographic wear/loosening. Crepitus was reported more frequently in CS design.

Conclusion: Most studies comparing PCL sacrificing (CS) versus retaining (CR) TKRs are short term. In this large, long term, single implant CR versus CS study, no differences were found in Kaplan-Meier survivorship, health-related outcomes or patient satisfaction. The CS design had more range of motion, but also a higher incidence of peripatellar crepitus than the CR design. We conclude that both CR and CS TKR designs can yield excellent long term clinical outcomes.