Purpose: To investigate the effects of including balance training in a preoperative strengthening intervention on balance and functional outcomes in patients undergoing total knee replacement (TKR) and compare these effects to those induced by preoperative strengthening and no intervention.
Methods: Eighty-two subjects scheduled for TKR were randomly allocated into the strengthening (ST, n = 28) group: a preoperative lower limb strengthening intervention; the strengthening + balance (ST + B, n = 28) group: same intervention augmented with balance training; and the control group (n = 26). The Berg Balance Scale (BBS) and the function in daily living subscale of the Knee Injury and Osteoarthritis Outcome Score (KOOS-ADL) were the primary outcomes. The secondary measures included balance and mobility, self-reported status, and knee function. The outcomes were assessed at baseline, 1 week before surgery, and 2, (primary endpoint), 6 and 52 weeks after surgery.
Results: Compared with the controls, the participants in the ST and ST + B groups presented significant improvements from baseline to the end of the preoperative intervention in BBS (p = 0.005) and KOOS-ADL (p < 0.001). At 6 weeks post-surgery, the knee extensor strength values were similar in the two treatment groups and significantly higher than that in the controls. Overall, the participant outcomes in all groups stabilized at 1 year after surgery.
Conclusion: A preoperative strengthening intervention, regardless of whether it is complemented with balance training, enhances strength but not balance or functional outcomes at 6 weeks after surgery. Patients are expected to present similar performance at 1 year postoperatively, but adequately statistically powered trials are needed to confirm the findings.
Level of evidence: II.
Trial registration: NCT02995668.
Keywords: Exercise therapy; Knee osteoarthritis; Muscle strength; Postural balance; Preoperative period; Total knee arthroplasty.