Resistance exercise training to improve post-operative rehabilitation in knee arthroplasty patients: A narrative review

Knee osteoarthritis is associated with deficits in muscle strength, muscle mass, and physical functioning. These muscle-related deficits are acutely exacerbated following total knee arthroplasty (TKA) and persist long after surgery, despite the application of standardized rehabilitation programs that include physical/functional training. Resistance exercise training (RET) has been shown to be a highly effective strategy to improve muscle-related outcomes in healthy as well as clinical populations. However, the use of RET in traditional rehabilitation programs after TKA is limited. In this narrative review, we provide an updated view on whether adding RET to the standard rehabilitation (SR) in the recovery period (up to 1 year) after TKA leads to greater improvements in muscle-related outcomes when compared to SR alone. Overall, research findings clearly indicate that both muscle strength and muscle mass can be improved to a greater extent with RET-based rehabilitation compared to SR. Additionally, measures of physical functioning that rely on quadriceps strength and balance (e.g., stair climbing, chair standing, etc.) also appear to benefit more from a RET-based program compared to SR, especially in patients with low levels of physical functioning. Importantly though, for RET to be optimally effective, it should be performed at 70%-80% of the one-repetition maximum, with 3-4 sets per exercise, with a minimum of 3 times per week for 8 weeks. Based upon this narrative review, we recommend that such high-intensity progressive RET should be incorporated into standard programs during rehabilitation after TKA. Schematic summary of this narrative review. Osteoarthritis is associated with a decline in muscle strength, mass, and function (1). After total knee replacement a further decline in muscle strength, mass, and function is observed (2). Although standard rehabilitation results in a partial or (sometimes) full recovery in these outcomes (3a), rehabilitation involving high-intensity resistance exercise training leads to greater improvements in muscle strength, muscle mass, and physical functioning compared to standard rehabilitation (3b). image Following standard rehabilitation (SR) protocols, patients recovering from total knee replacement still have deficits in muscle strength, muscle mass, and physical functioning compared to their healthy counterparts. Rehabilitation involving high-intensity resistance exercise training (RET) following total knee replacement leads to greater improvements in muscle strength, muscle mass, and physical functioning compared to SR. We recommend incorporating high intensity RET in the SR following total knee arthroplasty.