Men and Women Demonstrate Differences in Early Functional Recovery After Total Knee Arthroplasty

Abstract Objective To investigate whether sex affects the trajectory of functional recovery after total knee arthroplasty (TKA). Design Retrospective analysis from a historical database containing data from 3 prospective clinical trials and a pilot study. Setting Clinical laboratory setting. Participants Recruitment across studies was restricted to patients who underwent an elective unilateral TKA for the treatment of osteoarthritis and were between 50 and 85 years of age (N=301). Interventions Across all 4 studies, patients received a TKA and physical therapy intervention. Measures of physical function and strength were assessed before TKA and 1, 3, and 6 months after TKA. Main Outcome Measures Using a repeated-measures maximum likelihood model, statistical inference was made to estimate the changes in outcomes from before surgery to 1, 3, and 6 months after TKA that were stratified by sex. Muscle strength was assessed during maximal isometric quadriceps and hamstrings contractions. Muscle activation was assessed in the quadriceps muscle. Physical function outcomes included timed Up and Go (TUG) test, stair climbing test, and 6-minute walk test (6MWT). Results Women demonstrated less decline in quadriceps strength than did men at 1, 3, and 6 months after TKA ( P