Quantitative Analysis of Functional Mobility in Elderly Patients Following Total Knee Arthroplasty via the Transquadriceps Approach

In a context of rising demand for total knee arthroplasty (TKA) in older adults and persistent uncertainty about long-term functional recovery quality, this study evaluated elderly patients’ mobility after unilateral TKA via a transquadriceps approach using instrumented Timed Up and Go (TUG) tests. In this observational, retrospective, descriptive study, 54 patients treated between 2022 and 2024 at a tertiary hospital were invited, and 19 met inclusion criteria (age 50–80, Kellgren–Lawrence ≥4). Participants performed three TUG trials at two postoperative time points (mean 17.3 and 42.8 months), with a G-Walk inertial sensor capturing 15 kinematic variables. Descriptive statistics, Shapiro–Wilk tests, paired t-tests, Wilcoxon signed-rank tests, effect sizes (Cohen’s d, r), and Spearman/Pearson correlations were applied. Total TUG duration remained stable (14.97 ± 3.48 vs. 15.47 ± 2.93 s; p = 0.58), while mid-turning peak velocity increased significantly (106.44 ± 30.96 vs. 132.77 ± 30.82°/s; p = 0.0039; r = 0.88). End-turning velocity and sit-to-stand parameters showed moderate to small effect-size gains without statistical significance. These findings indicate that, beyond the first postoperative year, patients refine movement fluidity and motor control—especially during turning—underscoring the value of segmented, sensor-based assessments and the need for extended rehabilitation protocols emphasizing rotational control and balance.