Index Procedure Length of Stay and Achievement of Patient Acceptable Symptom State Predict Outcomes of Contralateral Total Hip Arthroplasty Within 1-Year.
BACKGROUND Many patients who have bilateral hip osteoarthritis eventually undergo contralateral total hip arthroplasty (THA), yet limited data exist on how recovery differs between staged procedures performed within one year. This study evaluated differences in patient-reported outcomes and healthcare utilization following staged bilateral THA and identified predictors of suboptimal outcomes after the second surgery. METHODS We retrospectively reviewed a prospective institutional registry to identify patients who underwent staged bilateral primary THA within one year (n = 680) and completed one-year postoperative patient-reported outcome measures (PROMs) for both procedures. The primary outcomes included discharge disposition, prolonged lengths of stay (LOS ≥ three days), 90-day readmission, and one-year reoperation. The secondary outcomes included Hip Disability and Osteoarthritis Outcome Score (HOOS) Pain, HOOS Physical Function Shortform (PS), and Joint Replacement subscale (JR) scores. Minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) thresholds were applied. Logistic regression identified predictors of suboptimal second-side outcomes. RESULTS Readmission (4.9 versus 2.8%, P = 0.045) and reoperation (3.1 versus 0.6%, P = 0.001) were more frequent after the second THA. Patients who had a prolonged LOS after the first THA had 20-fold greater odds of prolonged LOS after the second. The one-year PROM scores were similar across surgeries, but symptom improvement was consistently lower after the second THA (HOOS Pain: 58 versus 50, P < 0.001; PS: 43 versus 34, P < 0.001; JR: 46 versus 38, P < 0.001). Failure to achieve MCID was more common after the second THA, while PASS rates remained stable. Failure to reach PASS thresholds after the first THA strongly predicted failure after the second (ORs [odds ratios] 7.7 to 14.8). CONCLUSION Patients experienced diminished improvement and greater healthcare utilization rates after their second surgery. Poor recovery following the first THA was highly predictive of second-side failure. These findings support individualized surgical timing and counseling strategies based on early recovery trajectories.