Trajectories of pain and function in the first five years after total hip and knee arthroplasty

Aims To determine the trajectories of patient reported pain and functional disability over five years following total hip arthroplasty (THA) or knee (TKA). Methods A prospective, longitudinal cohort sub-study within National Joint Registry (NJR) was undertaken. In all, 20,089 patients who underwent primary THA 22,489 TKA between 2009 2010 were sent Oxford Hip Score (OHS) Knee (OKS) questionnaires at six months, one, three, postoperatively. OHS OKS disaggregated into function subscales. k-means clustering procedure assigned each to a trajectory group for function. Ordinal regression used predict membership using baseline score, age, BMI, index multiple deprivation, sex, ethnicity, geographical location, American Society Anesthesiologists grade. Results Data described two discrete function: ‘level 1’ responders (around 70% cases) in whom high level improvement is sustained years, 2’ had improvement, but lower level. Baseline variables only weak predictors modest trajectory. Those with worse tended show greater likelihood Six-month patient-reported outcome measures data reliably predicted class five-year both Conclusion The available preoperative not reliable postoperative after TKA. Reviewing outcomes months postoperatively indicator years. Cite this article: Bone J 2021;103-B(6):1111–1118.