Evaluation of a new decision tree in acetabular fracture adapted to recent evolutions: a retrospective, monocentric observational study before/after

INTRODUCTION: Elderly patients represent the fastest-growing subgroup of acetabular fractures. Numerous studies have highlighted the differences between young and elderly patients. Therefore, treatment strategies must incorporate the specificities of both elderly and young patients. The objective of this study was to evaluate the outcome of internal fixation using a new decision tree, including the geriatric population. HYPOTHESIS: Our hypothesis was that adherence to this decision tree would address recent changes in indications with results at least equivalent to our previous practice. METHODS: A single-center, retrospective, before-and-after cohort study evaluating the radiological outcomes of 82 patients operated on for acetabular fractures between January 2020 and December 2022 using a new decision tree. Epidemiological data, functional outcomes via the Oxford Hip Score (OHS), Postel Merle d'Aubigné (PMA), and Harris Hip Score (HHS), as well as complications were assessed. The quality of reduction was measured using computed tomography (CT) measurements. Failure was defined as poor reduction (gap or step >3 mm) or the need for total hip arthroplasty (THA) within 12 months postoperatively. Data were compared with those from our previous series without a decision tree of 156 patients operated on between January 2005 and December 2014. RESULTS: The mean age was 53.7 years (versus 40.3 years), reflecting the increasing proportion of older adults among patients operated for acetabular fractures (p < 0.001). Fracture patterns evolved from predominantly transverse and posterior wall fractures (34/156, 21.8% vs. 4/82, 4.9%; p = 0.0006) toward a predominance of anterior column with posterior hemitransverse fractures (25/82, 30.5% vs. 28/156, 17.9%; p = 0.03) and both-column fractures (25/82, 30.5% vs. 25/156, 16.0%; p = 0.009). The most used approach was the modified Stoppa approach (33 fractures, 40%) with quadrilateral surface-supported plates. Reduction was significantly improved, with only 13 poor reductions (16%) versus 52 poor reductions (37%), p = 0.004. The rate of early THA was significantly reduced (3/82, 3.7% versus 20/156, 12.8%, p = 0.02). Functional outcomes were excellent or good in 83% (68/82) for OHS, 70% (57/82) for HHS and PMA. Early resumption of weight-bearing in elderly patients did not alter functional outcomes. CONCLUSION: Adherence to our decision algorithm, which includes the specific characteristics of geriatric patients, results in satisfying reduction and a low rate of conversion to early THA, with satisfactory functional outcomes. These results could be explained by the generalization of the modified Stoppa approach and plates adapted to geriatric fracture patterns with quadrilateral surface support allowing early reloading. This study has shown the need for an improvement of this decision tree including new percutaneous surgery techniques. LEVEL OF EVIDENCE: III; retrospective comparative study.