Functional versus patient-reported outcome of the bicruciate and the standard condylar-stabilizing total knee arthroplasty.

INTRODUCTION: The purpose of this retrospective comparative analysis in patients undergoing primary total knee arthroplasty (TKA) was to evaluate whether different TKA implant design would influence patient-rated outcomes, functioning, and range of motion (ROM). A secondary purpose of this study was to test for relationships between the patient-rated outcomes and the passive ROM.
MATERIALS AND METHODS: Thirty-one patients who had a primary bicruciate stabilized TKA performed between May 2010 and November 2012 were retrospectively reviewed and compared with a cohort of 30 patients who had condylar-stabilizing TKA during the same period.
RESULTS: No significant differences were observed between the two groups with respect to preoperative demographic characteristics, ROM and radiographic knee alignment. At a mean follow-up of 37 months (SD 7), the Triathlon group had higher mean Knee Injury and Osteoarthritis Outcome Score (KOOS) score in all subscales and a higher Knee Society Score (KSS) score than the Journey group. This difference was statistically significant for the KOOS subscales of pain (p = 0.0099) and activities of daily living (ADL) (p = 0.0003), as well as the KSS score (p = 0.03846). The ROM was significantly higher in the Journey group when compared to the Triathlon group (p = 0.0013). No significant correlation was observed between the ROM and KOOS pain, QOL and ADL subscores and KSS score.
CONCLUSIONS: Postoperative knee ROM and patient perception of knee function after primary TKA can be affected by the different prosthetic designs. However, functionality afforded by the bicruciate TKA is not equivalent to patient satisfaction. LEVEL OF EVIDENCE: III.