Efficacy of preoperative progressive resistance training in patients undergoing total knee arthroplasty: 12-month follow-up data from a randomized controlled trial

Abstract

Objective: The aim of this study was to investigate the effect of adding four weeks preoperative progressive resistance training (PRT) to four weeks postoperative PRT on patient function, muscle strength, and other outcomes 12 months after total knee arthroplasty (TKA). Design: Twelve-month follow-up data from a previously published randomized controlled trial. Setting: Aarhus University Hospital, Silkeborg Regional Hospital, and Aarhus University. Subjects: A total of 59 patients scheduled for TKA were enrolled in a single-blinded, clinical randomized controlled trial. Interventions: Participants were randomized to preoperative PRT (intervention group) or to a control group who “lived as usual” the last four weeks before TKA. The intervention group completed four weeks preoperative and four weeks postoperative PRT, whereas the control group only completed four weeks postoperative PRT. Main follow-up measures were as follows: the 30-second Chair Stand Test (primary outcome), Timed Up and Go Test, walk tests, knee extensor, and knee flexor muscle strength and patient-reported outcomes. Statistical analyses were performed according to the intention-to-treat principle. Results: No significant group differences were observed for the primary outcome 30-second Chair Stand Test (4.0 repetitions versus 2.4 repetitions, P = 0.067) or for other functional performance outcomes. The intervention group had significantly higher weight-normalized knee extensor muscle strength (0.5 Nm/kg versus 0.2 Nm/kg, P = 0.002) and knee flexor muscle strength (0.3 Nm/kg versus 0.2 Nm/kg, P = 0.042) in the operated leg when compared to the control group. No significant group differences for patient-reported outcomes. Conclusion: The study supports the use of short-term high-intensity resistance training before TKA as it induces a long-lasting effect on muscle strength, while it may have no discernible effect on functional performance.