Use of Sensors in Rehabilitation of Patients Undergoing Knee Arthroplasty: A Systematic Review

Abstract

Aims: To characterize the use of inertial sensors for assessing mobility, function, and gait in patients undergoing unilateral knee arthroplasty for advanced osteoarthritis. Study Design: Systematic review. Place and Duration of Study: Searches were performed in PubMed, Embase, Scopus and Web of Science databases with no restrictions on date, language, or disease severity. Study selection was completed in 2025. Searches were last performed in 2025. Methodology: This review was registered with PROSPERO (CRD420251002284) and conducted according to PRISMA guidelines. Two independent reviewers screened titles, abstracts, and full texts using predefined inclusion and exclusion criteria. Risk of bias was assessed using a 10-item adapted Downs & Black scale. Data on study populations, experimental protocols, and gait parameters were extracted and synthesized descriptively. Results: Twenty-one cross-sectional studies were included, comprising 758 patients post-TKA and approximately 210 healthy controls. Inertial sensors ranged from 1 to 15 units, most placed on the lower back or pelvis. Walking protocols spanned 6–40 m courses, treadmill tests, oval circuits, and "free-living" monitoring. The primary parameters collected were spatiotemporal (speed, cadence, step length, phase durations) and kinematic (knee joint angles and pelvis/trunk movements). Studies demonstrated good reliability (ICC > 0.85) and accuracy (< 5° angular error). None explicitly investigated differences by prosthesis type. Findings reveal persistent spatiotemporal deficits and kinematic alterations following TKA. Conclusion: Wearable inertial sensors appear to be valid and feasible tools for capturing mobility, function, and gait outcomes after knee arthroplasty. However, substantial methodological heterogeneity (e.g., sensor placement, sampling rates, assessment protocols, and outcome definitions) limits cross-study comparability and precluded meta-analysis. Standardization of protocols and improved reporting, together with higher-quality comparative studies (including evaluation of implant design effects), are priorities to support clinical implementation.