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Correspondence to Author: Helder Rocha da Silva Araújo, Andrei Machado Viegas da Trindade, Davi de Souza Garcia, Enio Chaves de Oliveira, Fernanda Grazielle da Silva Azevedo Nora. 

Department of Orthopedics and Traumatology HC/UFG – Hospital das Clínicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil.
Department of Orthopedics and Traumatology HMAP – Hospital Municipal de Aparecida de Goiânia, Aparecida de Goiânia, Goiás, Brazil.
AMPLITUDE LATAM – Amplitude Surgical Latam, Rio Claro, São Paulo, Brazil.
Department of Surgery HC/UFG – Hospital das Clínicas, Universidade Federal de Goiás, Goiânia, Goiás, Brazil.
LAM – Movement Architecture Laboratory UFG – Universidade Federal de Goiás, Goiânia, Goiás, Brazil Avenida Esperança s/n, Campus Samambaia, Goiânia, Goiás, Brazil.

DOI: 10.52338/tjop.2026.5560

Abstract:

Objective: To quantify the influence of surgeon experience on dynamic tibiofemoral contact mechanics and gait kinematics after navigationassisted total knee arthroplasty (TKA) using a finite element–inspired gait simulation framework.
Methods: A retrospective observational study was conducted using prospectively collected intraoperative navigation datasets from primary unilateral TKA performed with the SCORE® mobile-bearing prosthesis and Amplivision® optical navigation system (Amplitude Surgical, Valence, France). Surgeons were stratified into E1 (beginner; ≤15 procedures; 32 surgeons, 279 cases) and E2 (experienced; >21 procedures; 11 surgeons, 349 cases). A reduced-order finite element–inspired proxy model implemented in Python simulated continuous gait (0–100%) to estimate femoral and tibial contact pressures, polyethylene inserts contact stress (10–20 mm), knee range of motion, dynamic ligament balance (GAP), and coronal-plane angles. Intergroup comparisons used the Mann–Whitney U test; effect sizes (Cohen’s d and Cliff’s δ) with 95% bootstrap confidence intervals (2,000 iterations) were computed.
Results: Across all contact mechanics outcomes, E1 reconstructions demonstrated higher loading than E2, including mean femoral contact pressure (26.74 ± 21.59 vs 22.44 ± 17.34 MPa; p = 0.083) and mean tibial contact pressure (26.21 ± 21.16 vs 21.99 ± 17.00 MPa; p = 0.079). Peak pressures followed the same pattern (femoral: 0.44 ± 0.36 vs 0.37 ± 0.29 MPa; tibial: 0.43 ± 0.35 vs 0.36 ± 0.28 MPa; p = 0.083). Polyethylene insert stress decreased with increasing thickness (10→20 mm) in both cohorts yet remained consistently higher in E1. Kinematic variables were also greater in E1, including range of motion (74.1 ± 3.8 vs 72.9 ± 3.5°; p = 0.088), mean GAP (2.21 ± 0.90 vs 0.67 ± 0.32 mm; p = 0.081), mean varus angle (1.12 ± 0.46 vs 0.98 ± 0.39°; p = 0.087), and mean valgus angle (2.01 ± 0.62 vs 1.82 ± 0.55°; p = 0.090). Effect sizes were uniformly small-to-moderate (Cohen’s d ≈ 0.22–0.24; Cliff’s δ ≈ 0.10–0.12).
Conclusion: Surgeon experience was associated with a systematically more favorable biomechanical profile during simulated gait after navigation-assisted TKA, characterized by reduced tibiofemoral contact loading, lower polyethylene stresses across insert thicknesses, and more constrained dynamic joint behavior.

Keywords: Arthroplasty, Replacement, Knee; Finite Element Analysis; Gait; Computer-Assisted Surgery; Biomechanical Phenomena.

Citation:

Dr. Fernanda Grazielle da Silva Azevedo Nora, Surgeon Proficiency Determines Tibiofemoral Contact Pressures, Dynamic Ligament Laxity, And Polyethylene Wear Risk In Navigation-Assisted Total Knee Arthroplasty: A Finite Element. The Journal of Orthopaedics 2026.