Evaluating the Correlation Between Markerless Gait Analysis and PROM Scores in Hip and Knee Arthroplasty-A Pilot Cross-Sectional Study.

Several gait parameters have demonstrated associations with PROMs in THA and TKA. However, existing gait-PROMs studies are longitudinal and relied on lab-based or wearable systems. This pilot study aimed to assess cross-sectional associations between gait parameters measured using a portable, markerless gait analysis system and PROMs 12 months following THA and TKA. In this prospective cross-sectional study, 58 patients (32 THA, 26 TKA) were assessed at 12 months postoperatively. PROMs consisted of the Oxford Hip/Knee Scores (OHS/OKS), EQ-5D-5L, and EQ-VAS. Gait analysis was conducted using a Kinect-based markerless motion capture system, and kinematic and spatiotemporal parameters were recorded. Univariate and multivariable linear regressions, subgroup regressions, and correlations analyses were used for the analysis. Greater operated hip flexion in THA patients was significantly associated with better pain and function (OHS; β = 0.335, p = 0.0049) and higher quality of life (EQ-5D-5L; β = 0.006, p = 0.0154). In TKA patients, worse knee extension in both the operated (β = -0.453, p = 0.0231) and non-operated (β = -0.354, p = 0.0134) limbs was associated with lower quality of life (EQ-VAS). Spatiotemporal parameters including operated step length (β = 0.002, p = 0.0447) and non-operated stride length (β = 0.126, p = 0.0492) in THA were associated with higher EQ-5D-5L. This pilot study provides preliminary evidence supporting the clinical relevance, of specific gait parameters as cross-sectional measures at 12 months, adding to longitudinal evidence. In addition, this is the first study to demonstrate these associations using a portable, markerless system well-suited for widespread clinical use. Together, portable markerless gait analysis may serve as a promising objective complement to PROMs for routine postoperative assessment.