Abstract
Background
While many studies have investigated long-term outcomes after lower limb arthroplasty, rather less is known about the trajectory of short-term outcomes in the first post-operative year. It is difficult for a surgeon to know when, in terms of disease severity, it is best to operate, or to make an accurate prediction of the patient pattern of post-operative recovery. We explored the trajectory of change in pain and function following primary hip and knee arthroplasty and the influence of pre-operative self-reported symptoms on post-operative improvements.
Methods
A prospective UK cohort study of 164 patients undergoing primary hip (n=80) or knee (n=84) arthroplasty. WOMAC pain and function measures were collected pre-operatively and at 3 and 12 months post-operatively. Hip and knee arthroplasties were analysed separately, and patients were split into two groups: those with high or low symptoms pre-operatively. Multilevel regressions were used for each outcome (pain and function), and the trajectory of change (0–3 months and 3–12 months) charted. The study was approved by Southwest 4 Research Ethics Committee (09/H0102/72) and all patients provided informed, written consent. The authors have no competing interests to disclose.
Results
Most improvement after hip arthroplasty occurred within the first 3 months post-operative. One year after surgery there was no difference in the outcomes between patients with high or low pain/function scores pre-operatively. Similarly, most improvement after knee arthroplasty occurred in the first 3 months. Improvement was greater for those patients with worse pre-operative functional disability and pain, although these patients never ‘caught-up’ with those with less severe pre-operative symptoms.
Conclusions
Earlier intervention may be warranted for patients undergoing knee arthroplasty compared to hip arthroplasty to achieve the best post-operative patient-reported outcomes.
Level of evidence
2b, Individual cohort study.
