Purpose After a total knee arthroplasty (TKA), ensuring rehabilitation is continued at home is essential for a successful recovery. The aim of this randomized clinical trial (NCT04155957) was to demonstrate the safety and efficacy of an interactive telerehabilitation system (ReHub®) to guide and provide feedback during exercise in the postoperative period of a fast-track TKA program. Methods Fifty-two patients who underwent TKA were randomized to intervention (N = 26) or control (N = 26). Upon discharge, they followed a 4-week plan of 5 daily exercises and up to 10 physiotherapy home visits. The intervention group performed exercises with ReHub® autonomously, control did not use any auxiliary device. Data were collected 1) on the day of discharge, 2) after 2 weeks and 3) after 4 weeks. Results Telerehabilitation patients showed higher adherence to exercise (p = 0.002) and greater quadriceps strength (p = 0.028). No significant differences between groups were found in other outcomes. Only 1 adverse event was linked to ReHub®. Patients gave the platform high System Usability Scale scores (83/100). Conclusion Interactive telerehabilitation with ReHub® during a post-TKA exercise program is effective, safe, and well-received by patients. It provides real-time performance feedback and ensures communication. Quadriceps strength and adherence to the exercise plan are improved with ReHub®.