EARLY FAILURE OF ACETABULAR ORIF IN SEVERE OBESITY: RETHINKING SALVAGE STRATEGY IN A YOUNG PATIENT

Abstract

Introduction: Open reduction and internal fixation (ORIF) remains the gold standard for displaced acetabular fractures in young patients. However, severe obesity imposes extreme cyclic mechanical loading that may render ORIF biologically futile regardless of surgical technique. When fixation fails in this setting, salvage arthroplasty presents a formidable challenge,compounded further by concurrent sciatic nerve injury and the inherent tension between joint preservation and mechanical reality in a young patient. We report this case to challenge the default surgical paradigm and propose a framework for rethinking decision-making in this high-risk intersection.

Case Presentation: A 35-year-old male weighing 120 kg sustained a left posterior-superior acetabular fracture following a motor vehicle accident and underwent ORIF at an outside institution two days post-injury. Within weeks, he developed progressive hip pain, wound erythema, systemic chills, and clinical hip subluxation. Plain radiograph and CT 3D reconstruction confirmed implant failure with severe acetabular comminution and loss of femoral head containment. Sciatic nerve palsy and leg length discrepancy were established on examination. After careful pre-operative planning, bipolar hemiarthroplasty via a posterolateral approach was performed at our institution (Bali Royal Hospital). Intraoperatively, the retained posterior column plate provided structural scaffolding for the bipolar articulation. The patient was discharged on post-operative day five with residual lower limb paraesthesias managed conservatively.

Discussion: The failure in this case was not incidental,it was biomechanically foreseeable. In a 120 kg patient, peak hip joint reactive forces may exceed 900 kg per step, subjecting a comminuted posterior acetabular construct to repetitive cantilever bending that promotes fatigue failure at the implant-bone interface before consolidation occurs. A structured counterfactual analysis raises a provocative question: had primary arthroplasty been chosen at the index procedure, would the patient have been spared a second major operation, cumulative sciatic nerve risk from two posterior approaches within three months, and a two-month interval of pain and progressive joint destruction? Current literature supports the durability of modern arthroplasty constructs in this setting, yet the paradigm of ORIF as the default 'joint-preserving' choice in young patients persists,even when the joint, under these mechanical conditions, may not be preservable.

Conclusion: Bipolar hemiarthroplasty is a viable salvage strategy following early ORIF failure in a severely obese young patient with posterior-superior acetabular fracture. The retained posterior column hardware can serve as a structural scaffold for bipolar articulation in cases of compromised acetabular bone stock. Timely recognition of failure and decisive surgical re-intervention are critical to preventing irreversible joint destruction.

Clinical Importance: Severe obesity must be recognised not merely as a comorbidity but as a fundamental biomechanical contraindication to standard ORIF constructs in comminuted acetabular fractures. Surgeons should explicitly discuss primary arthroplasty as an alternative,even in young patients,when the convergence of extreme BMI, posterior wall comminution, and suboptimal bone quality predicts fixation failure. The question is no longer whether we can fix it, but whether fixing it serves the patient.