Summary

Implementing a digital and interactive knee brace improves range of motion after total knee arthroplasty

Abstract

**Introduction:** Restoring range of motion (ROM) after total knee arthroplasty (TKA) is essential for improving the quality of life in severe gonarthrosis. The use of telerehabilitation tools has gained prominence post-COVID-19 as a supplement to standard protocols.
**Objective:** To determine the effect on ROM during the first 8 weeks post-TKA by adding a device that enables telerehabilitation.
**Method:** Cohort study. A knee brace with motion sensors was developed, which connects to a mobile device screen, allowing for remote, playful, and guided rehabilitation. The calculated sample size was 30 KA per group. The control group did not use the brace, while the experimental group had free access to the brace for 8 weeks. Patients eligible for TKA over 60 years old were included. Exclusions were constrained TKA and dementia. Weekly follow-ups were conducted to supervise, adjust exercises, and measure ROM for 8 weeks post-TKA. A longitudinal data model with random effects was estimated, adjusting for covariates such as age, sex, and other significant variables at baseline comparison.
**Results:** Baseline comparisons show a higher proportion of independent patients (Barthel scale), less preoperative pain (visual analog scale), lower baseline flexion, and poorer physical performance in the control group. The longitudinal data model with random effects and covariates showed that the use of the brace significantly improved active flexion (7.67, p=0.002), passive flexion (6.81, p=0.037), and passive extension (3.39, p=0.035).
**Discussion/Conclusion:** Increasing exercise volume with the brace, due to its availability and usability, significantly improves ROM in the first 8 weeks post-TKA, adjusting for age, sex, prior ROM, pain, and level of dependence and physical performance.