Management and outcome of displaced acetabular fractures in the oldest-old: a retrospective analysis of orif and acute total hip arthroplasty

PURPOSE: The optimal surgical management of geriatric acetabular fractures remains controversial. This study compared short-term outcomes following open reduction and internal fixation (ORIF) or acute total hip arthroplasty (THA) with or without additional osteosynthesis (THA ± ORIF) and evaluated the impact of a new treatment algorithm (standard operative procedure, SOP) that favors the use of THA in elderly and medically comorbid patients. METHODS: In this retrospective cohort study, patients aged ≥ 70 years with isolated trauma-associated unilateral displaced acetabular fractures who underwent surgical treatment at a single Level I trauma center between January 2016-March 2019 (old SOP) and January 2022-December 2025 (new SOP) were included. Patients underwent either ORIF or THA ± ORIF. The transitional implementation phase of the new SOP was excluded. The primary outcome was postoperative time to gait mobilization. Secondary outcomes included pain at discharge, functional mobility, complications, mortality, quality of fracture reduction, and conversion to THA following initial ORIF. Because treatment allocation followed different institutional algorithms across the study periods, the study primarily evaluates an evolving treatment strategy rather than directly comparing ORIF and THA. RESULTS: Sixty patients (median age 82 years, IQR 78-87; median Charlson Comorbidity Index 5, IQR 4-7) were included. The most common fracture pattern according to the Letournel classification was the anterior column with posterior hemitransverse fracture (n = 35). Thirty-five patients underwent ORIF and 25 underwent THA ± ORIF. Compared with ORIF, THA ± ORIF was associated with significantly faster remobilization (median 3 vs. 6 days, IQR 2-3 vs. 4-7; p < 0.05), lower pain levels at discharge (VAS 1-3: 96% vs. 37.1%; p < 0.05), and superior functional mobility at discharge. Complication rates, readmissions, length of stay, and in-hospital mortality did not differ significantly between groups. These findings remained consistent after implementation and refinement of the newly introduced SOP despite the increasing use of THA ± ORIF in older and more comorbid patients. CONCLUSION: A structured treatment algorithm incorporating THA ± ORIF was associated with earlier remobilization and lower pain levels at discharge without increasing complication rates compared with ORIF in geriatric patients with displaced acetabular fractures. These findings support differentiated treatment allocation and the safe use of acute THA in carefully selected elderly patients.