App-based rehabilitation program after total knee arthroplasty: a randomized controlled trial

INTRODUCTION: New app-based programs for postoperative rehabilitation have been developed, but no long-term study has been published to date. Thus, a prospective randomized control trial with 2-year follow-up was performed to evaluate the effectiveness of app-based rehabilitation (GenuSport) compared to a control group after total knee arthroplasty (TKA). METHODS: Between April and October 2016, 60 patients were enrolled in the study. Twenty-five patients were lost to follow-up, leaving 35 patients undergoing TKA for inclusion. In this group, twenty patients received app-based exercise program and 15 were randomized to the control group. The mean age was 64.37 ± 9.32 years with a mean follow-up of 23.51 ± 1.63 months. Patients in the app group underwent an app-based knee training starting on the day of surgery; whereas, patients in the control group underwent regular physiotherapy. Functional outcome scores using the Knee Injury and Osteoarthritis Outcome Score (KOOS), Knee Society Score (KSS) and VAS of pain were analyzed. RESULTS: In the short term, significant differences between the app group and control group in time of 10-m walk (19.66 ± 7.80 vs. 27.08 ± 15.46 s; p = 0.029), VAS pain at rest and activity (2.65 ± 0.82 vs. 3.57 ± 1.58, respectively 4.03 ± 1.26 vs. 5.05 ± 1.21; p < 0.05) were observed. In the long term, a variety of different tendencies was found, highest in KSS Function with 76.32 ± 16.49 (app group) vs. 67.67 ± 16.57 (control group) (p = 0.130). Additionally, patients in the app group required less painkillers (10.0% vs. 26.7%) and more likely to participate in sports (65.0% vs. 53.3%). CONCLUSIONS: An app-based knee trainer is a promising tool in improving functional outcomes such as KSS function score and VAS after TKA. LEVEL OF EVIDENCE: Level II, prospective randomized control trial.