The objective of his study was to model change in lower extremity functional status of patients 1-year post total hip arthroplasty (THA) using the Lower Extremity Functional Scale (LEFS) and 6-minute Walk Test (6MWT); secondarily to provide clinicians with useful data to guide practice. Given the prevalence of THA and current resource pressures, standardized outcome measures play an important role in providing physical therapists with objective knowledge about postoperative recovery and prognosis.Seventy-five patients with a mean age of 61 and a diagnosis of hip osteoarthritis consented to participate in the study. Assessments were conducted preoperatively and at multiple time points up to 65-weeks after surgery. Recovery was modeled using a nonlinear robust regression analysis for clustered data. The predictive ability of age, body mass index, and preoperative score were explored. Gender based recovery curves were generated depicting the rate and amount of change in LEFS scores and 6MWT distances over the first year. Preoperative baseline 6MWT distance was the only covariate predictive of postarthroplasty 6MWT distances for both males and females. None of the covariates examined were significantly associated with postarthroplasty LEFS scores.
Although there were variations in the recovery curves by measure, general patterns were noted. A rapid increase in both self-reported and physical performance measure scores occurred up to 12-15 weeks with a slowing of recovery thereafter and a plateau observed around the 30-35 week mark for the 6MWT and later for the LEFS. The data can be used to make evidence-based decisions about prognosis and guide setting measurable treatment goals.