Gait kinematics and knee stability 10‐years following posterior‐stabilised total knee arthroplasty comparable to healthy adults >55

Purpose The purpose of this study was to compare the long‐term objective biomechanical and functional parameters of a high‐flexion total knee arthroplasty (TKA) design against healthy older adults to determine whether knee biomechanics are comparable in both populations. Methods One cohort of patients with a primary TKA, and a cohort of healthy adults over 55 years old with no musculoskeletal deficits or arthritis participated. Bilateral knee range of motion (RoM) was assessed with a goniometer, and gait patterns were analysed with a three‐dimensional‐motion capture system. An arthrometer quantified the anterior‐posterior laxity of each knee. Statistical analyses were performed in SPSS software (α = 0.05). Results Twenty‐three knees were replaced in 20 patients. At 9.8 ± 3.1 years postoperatively, patients' knees had a statistically significantly poorer RoM than healthy controls' knees (n = 23) due to limited flexion; p 7 mm; a known risk factor of instability. However, the knee flexion range was poorer. This likely led to bilateral pathological knee flexion patterns during downhill gait. Level of Evidence: Level III.