Clinically Relevant Gait Biomechanics Improvements After Total Knee Arthroplasty

Improved joint function is a primary goal of total knee arthroplasty (TKA), yet persistent postoperative deficits in joint biomechanics are common, and the link between these and other clinical outcomes is poorly understood. Evidence on clinically meaningful gait outcomes after arthroplasty is limited, hindering their uptake in clinical trials and technological innovations in arthroplasty. This paper examined the associations between gait outcomes and satisfaction after TKA and defined minimal detectable and clinically meaningful thresholds for gait outcome changes. Thirty-one patients underwent instrumented gait analysis immediately before and 1 year after TKA and were categorized as high (>90) and lower (≤90) satisfaction with their joint replacement after surgery. Sixteen (51.6%) patients self-reported high satisfaction, and 15 (48.4%) reported lower satisfaction. There were no pre-TKA gait differences between the groups, but higher satisfaction postarthroplasty was associated with more a biphasic pattern improvement of the knee flexion/extension moment during stance from presurgery to postsurgery (r = .59, P = .001). Most patients, however, did not achieve minimal detectable or meaningful clinically important improvements in knee biomechanics from pre-TKA to post-TKA. The established thresholds for meaningful improvement in biomechanical variables may be used in future studies to relate measures of patient satisfaction to objective gait outcomes.