Original Article

The learning curve of novel implant total knee arthroplasty system in high-volume university center

¹ Univ Lyon, Claude Bernard Lyon 1 University, IFSTTAR, LBMC UMR_T9406, 43 boulevard du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
² Orthopaedics Surgery and Sports Medicine Department, FIFA Medical Center of Excellence, Croix-Rousse Hospital, Lyon University Hospital, 103 Grande Rue de la Croix Rousse, 69004 Lyon, France
³ Department of Orthopaedic Surgery, Ghent University Hospital, C. Heymanslaan 10, 9000, Gent, Belgium
⁴ Department of Public Health, Orthopedic Unit, “Federico II” University, Via Pansini 5, 80131 Naples, Italy
⁵ LIBM – EA 7424, Interuniversity Laboratory of Biology of Mobility, Claude Bernard Lyon 1 University, 27-29 Boulevard du 11 Novembre 1918, 69100 Villeurbanne, France
⁶ Hospices Civils de Lyon, Hôpital Lyon Sud, Chirurgie Orthopédique et Traumatologique, 165 Chemin du Grand Revoyet, 69495 Pierre Bénite, France
⁷ University Lyon, Claude Bernard Lyon 1 University, Gustave Eiffel University, IFSTTAR, LBMC UMR_T9406, 25 Avenue François Mitterrand, 69675 Bron Cedex, France

^* Corresponding author: simon.messe@chu-lyon.fr

Received: 6 June 2025
Accepted: 6 July 2025

Abstract

Introduction: The learning curve associated with adopting new surgical systems in total knee arthroplasty (TKA) can significantly impact surgical efficiency and patient outcomes. This study aimed to evaluate the evolution of operative time with the KNEO^® (Groupe Lépine, Genay, France) posterior stabilized knee system and to analyze the learning curve for postoperative complications to achieve surgical proficiency. Method: This retrospective, multicentric study analyzed 481 patients who underwent primary TKA with the KNEO^® implant in a high-volume university center between 2020 and 2024. The evolution of operative time and postoperative complications requiring reoperation surgery were evaluated, with a follow-up period extending until January 2025, during which complications were monitored. The study included 481 patients with a mean age of 71.7 ± 8.0 years and a mean Body Mass Index of 29.0 ± 4.0 kg/m². The cohort comprised 308 female (64%) and 173 male (36%) patients. Results: The mean operative time significantly decreased from 83.5 min in the initial case to 63.0 min after 481 cases (p < 0.001). The learning curve showed an initial learning phase with high variability, followed by stabilization around 150 procedures and subsequent optimization. Postoperative complication rates showed a 31.9% reduction per group of 100 patients (β = −0.3848, p = 0.0075), indicating improved surgical proficiency and patient safety over time. Conclusion: The findings suggest that the KNEO^® system follows a measurable learning curve, with operative efficiency and complication rates improving as case volume increases. These results emphasize the importance of structured training and experience accumulation in optimizing patient outcomes when implementing new implant technologies.