Learning curve with a new primary total knee arthroplasty implant: a multicenter perspective with more than 2000 patients

Background: This study provides an example for evaluating learning curve when introducing a new knee system. Methods: Thirty-five investigators across 22 sites prospectively implanted 843 subjects with currently available products (group A). Seventy-seven investigators across 48 sites prospectively implanted 2330 subjects with the ATTUNE Knee System; in which the first 10 subjects for each surgeon were the learning curve cases (group B, N = 611), and the later subjects were designated as group C (N = 1719). Surgical time, rates of intraoperative and early postoperative complications, and patient-reported outcome measures (PROMs) at a minimum of 1 year were compared. Results: Mean (standard deviation) surgical time was 72.0 (21.6) minutes for group A, 83.0 (24.2) for group B, and 72.1 (24.1) for group C (P < .001 for group B vs group C; P = .955 for group C vs group A). Intraoperative, early (<90 day) complication rates, and PROMs were similar for all groups. Conclusions: The new knee system learning curve was characterized by a slightly longer surgical time with no negative impact on complications or PROMs. Level of Evidence: III. Keywords: Total knee arthroplasty, Learning curve, Adverse events, Clinical outcomes, ATTUN