Functional Mobility Assessment after Unilateral Knee Arthroplasty: A Comparative Study of Two Prosthesis Types

Aims: To evaluate and compare the functional mobility of patients undergoing unilateral knee arthroplasty using two prostheses: fixed tibial plateau and rotating platform. This study addresses a gap in the existing literature by providing detailed insights into functional mobility patterns and prosthesis-specific outcomes.

Study Design: A prospective, observational, and comparative study with assessments conducted at two-time points: 12 to 24 months after surgery.

Place and Duration of Study: Conducted at a tertiary hospital for rehabilitation and readaptation, in partnership with a private university from March 2022 to December 2024.

Methodology: Thirty-six patients who had previously undergone unilateral knee arthroplasty were included, equally divided between fixed and rotating platform prostheses. The Timed Up and Go (TUG) test, performed with the G-WALK inertial sensor, captured 15 functional mobility variables across two time points. Statistical analyses included variance tests and correlations to identify changes between time points and groups.

Results: The mean TUG time increased from 14.47 ± 3.03 seconds to 15.24 ± 3.85 seconds without statistical significance (P=.301). However, the Sit-to-Stand phase significantly reduced duration (P=.036). The turning phase demonstrated significant improvements in both duration (P<.001) and speed (P<.001). No statistically significant differences were observed between prosthesis types in most variables. The comparison between fixed and rotating platform prostheses is clinically important as it provides insights for tailoring postoperative rehabilitation strategies.

Conclusion: Fixed and rotating platform prostheses demonstrated comparable functional performance, with specific improvements noted over time. The findings emphasize the value of inertial sensors in conducting detailed clinical assessments and suggest opportunities for further research to enhance prosthesis selection and rehabilitation protocols. This study contributes to clinical practice by offering evidence that supports personalized rehabilitation strategies.