Short term patient outcomes after total knee arthroplasty: Does the implant matter?

BACKGROUND: Newer implants for total knee arthroplasty (TKA) often gain market share at higher cost with little patient-reported and long-term clinical data. We compared outcomes after TKA using two different implants: DePuy PFC Sigma and Attune.

METHODS: Using a prospective data repository from an academic tertiary medical center, we analyzed 2116 TKAs (1603 Sigma and 513 Attune) from April 2011 through July 2016. Outcomes included length of surgery, length of stay, facility discharge, 90-day reoperation, range of motion (ROM) change, and patient-reported physical function (PCS).

RESULTS: There was no difference in length of surgery (Attune -2.87 min, P = 0.143). Implant type was not associated with extended LOS (>3 days) (OR 0.80, P = 0.439). There was no difference in facility discharge (OR 0.65, P = 0.103). Unadjusted 90-day reoperations were 0.3% for Sigma and 1.0% for Attune cohorts (P = 0.158). Sigma implants were associated with more ROM improvement in unadjusted analyses (+2.1 degree improvement P = 0.031). Fifty nine percent of the Sigma cohort and 49% of the Attune cohort achieved the minimal clinically important (MCID) change for PCS improvement, although there was no adjusted difference in achieving MCID (Attune OR 0.84, P = 0.435). There was no adjusted difference in absolute PCS improvement (Attune +0.12 score, P = 0.864).

CONCLUSIONS: Our data show no difference in physical function and most outcomes between Sigma and Attune. Attune implants had shorter absolute LOS, but there were no differences in extended LOS.