Effects of preoperative maximal strength training on muscle strength and function in total knee arthroplasty: A randomized controlled trial.

BACKGROUND

The efficacy of prehabilitation through preoperative strength training for individuals undergoing total knee arthroplasty (TKA) remains inconclusive.

OBJECTIVE

The present study aimed to evaluate the effects of maximal strength training (MST) before operation on muscle strength and physical function 3 weeks following TKA.

METHODS

48 individuals scheduled for fast-track unilateral primary TKA were randomized to MST (n = 24), performing 4 sets at 4 repetition maximum in seated leg press 3 times per week for 8 weeks, or control usual care (CON, n = 24). The primary outcome was bilateral leg press maximal strength. Secondary outcomes were performance-based physical function, including 10-step stair climbing, 30 s sit-to-stand, 40 m fast-paced walking, and unipedal stance tests, and self-reported physical function as knee injury and osteoarthritis outcome score-physical function short form (KOOS-PS), European quality of life 5 dimension, 5 Level, and forgotten joint score.

RESULTS

MST improved bilateral leg press 1RM relative to body weight after intervention (mean change 0.45, P < 0.0001), and there were between-group differences in the delta changes from baseline to preoperation (mean difference 0.43, P < 0.0001) and postoperation (mean difference 0.27, P < 0.001), favoring MST. MST also led to better maintenance of postoperative stair climbing (mean difference -3.38 s, P = 0.0013). Although the MST group experienced a significant preoperative improvement in sit-to-stand (mean change 2 repetitions, P = 0.0019), walking ability (mean change -2.28 s, P < 0.001), and KOOS-PS (mean change 8, P < 0.0001), these effects did not extend to postoperative outcomes.

CONCLUSIONS

The findings indicate that preoperative MST is safe and effective in improving muscle strength and preserving stair-climbing ability for individuals undergoing TKA, positioning MST as a pragmatic prehabilitation strategy.

CLINICAL TRIAL REGISTRATION: NCT05892133.