Recovery Curves for Patient Reported Outcomes and Physical Function After Total Hip Arthroplasty

Abstract

Background: Patient-reported outcome measures (PROMs) are frequently used for evaluating patient satisfaction and function following total hip arthroplasty (THA). Functional measures along with chronologic modeling may help set expectations perioperatively. Our goal was to define the trajectory of recovery and function in the first year following THA.

Methods: Prospective data from 1,898 patients in a multicenter study was analyzed. The PROMs included the Hip disability and Osteoarthritis Score for Joint Replacement and EuroQol-5 dimension. Physical activity was recorded on a wearable technology. Data was collected preoperatively and at 1, 3, 6, and 12 months postoperatively. Generalized estimating equations were used to evaluate outcomes over time.

Results: Significant improvement occurred between preoperative and postoperative time points for all PROMs. The PROMs showed the greatest proportional recovery within the first month postoperatively, each improving by at least 1 minimal clinically important difference (MCID). Daily steps and flights of stairs took longer to reach at least 1 MCID (3 months and 1 year, respectively). Gait speed and walking asymmetry returned to baseline by 3 months, but did not reach a MCID of improvement by 1 year.

Conclusion: Patients can be counseled that the greatest proportional improvement in PROMs is within 1 month after THA, while function surpasses preoperative baselines by 3 months, and gait quality may not improve until after 1 year. This can help set realistic expectations and target interventions toward patients deviating from the norm.

Keywords: patient reported outcome measures; physical function; recovery curves; total hip arthroplasty; wearable technology.