Comparison of Conversion and Primary Total Hip Arthroplasty in a Retrospective Study of 140 Patients: Recommendations for Tailored Interventions.

PURPOSE: Proximal femur fractures are commonly treated with cephalomedullary nails (CMN), dynamic hip screws (DHS), or closed reduction with percutaneous pinning (CRPP). Conversion total hip arthroplasty (cTHA) may be required for complications of these procedures. We compared cTHA outcomes with primary THA (pTHA). MATERIALS AND METHODS: This retrospective study included 140 patients (70 cTHA, 70 pTHA) at Brown University Health Hospitals between September 2022 and February 2024. cTHA patients had prior failed DHS, CMN, or CRPP fixation. pTHA patients underwent surgery for degenerative joint disease rather than trauma. Demographics, perioperative data, and postoperative outcomes were compared, and logistic regression identified predictors of complications. RESULTS: cTHA patients were older (71.6 vs. 66.3 years, P<0.01), more often female (75.7% vs. 55.7%, P=0.01), with longer surgical times (140.7 vs. 79.2 minutes, P<0.01), higher estimated blood loss (EBL) (378.1 vs. 224.3 mL, P<0.01), longer hospital stays (3.6 vs. 1.8 days, P<0.01), and higher complication rates (40.0% vs. 15.7%, P<0.01). Transfusions (14.3% vs. 2.9%, P=0.02) and skilled nursing facility discharges (42.9% vs. 17.1%, P<0.01) were also higher. Ninety-day emergency department visits, readmissions, reoperations, and dislocations were similar. High American Society of Anesthesiologists score (odds ratio [OR] 4.03, P=0.04), longer length of stay (OR 1.57, P<0.01), older age (OR 1.09, P<0.01), and higher EBL (OR 1.00, P=0.04) were independently associated with adverse outcomes. CONCLUSION: cTHA is associated with higher perioperative morbidity and greater resource utilization than pTHA, despite similar short-term reoperation and readmission rates. These findings support risk stratification and tailored perioperative management for cTHA patients.