Abstract
INTRODUCTION
Early postoperative strength loss is pronounced following total knee arthroplasty (TKA) and is largely the result of reduced muscular activation. High-intensity progressive rehabilitation may limit postoperative weakness and improve long-term outcomes, but no randomized controlled trials have examined its use after TKA. The purpose of this trial was to examine the efficacy of a high-intensity progressive rehabilitation protocol (HI) compared to a lower intensity (LI) rehabilitation protocol after TKA.
METHODS
One hundred and sixty-two subjects (aged 63±7 years, 89 females) were randomized to either the HI group or LI groups after TKA. The HI intervention consisted of an early initiation of intensive rehabilitation using progressive resistance exercise. The LI intervention was based on a synthesis of previously published standard TKA rehabilitation programs. Both groups were treated 2–3 times per week for 12 weeks. Outcomes included the stair climbing test, timed-up-and-go test, five-times sit-to-stand test, 6-minute walk test, isometric quadriceps and hamstring strength, quadriceps activation, surgical knee range of motion, and WOMAC. Secondary analysis evaluated whether outcomes differed depending on post-operative quadriceps activation. Outcomes were assessed preoperatively and at 1, 2, 3, 6, and 12 months postoperatively.
RESULTS
There were no significant differences between groups at any time point in functional performance, strength, activation, knee ROM, or WOMAC; or differences in adverse events. A planned secondary analysis indicated that there were differential effects of the HI intervention depending on postoperative quadriceps activation. Individuals in the HI group with higher postoperative activation demonstrated improved functional performance at one month compared to those individuals with lower activation in the HI group or all individuals in the LI group regardless of postoperative activation levels.
DISCUSSION
High-intensity progressive rehabilitation is safe for individuals after TKA, does not compromise ROM recovery following TKA, but may not lead to clinically significant earlier functional recovery.
