Lateral rectus abdominis approach fixation of a high-energy both-column acetabular fracture after total hip arthroplasty with retention of a stable acetabular cup: a case report.

Background: Acetabular fractures are intra-articular injuries with complex anatomy and demanding reduction requirements. Traumatic periprosthetic acetabular fractures after total hip arthroplasty (THA) are rare and particularly challenging because treatment must simultaneously address fracture stability and acetabular component stability. Case presentation: A 72-year-old woman sustained a high-energy road-traffic injury from an outside vehicle 10 years after left THA. Computed tomography (CT) demonstrated a comminuted both-column acetabular fracture with medial displacement of the quadrilateral surface and compromised periacetabular bone continuity, raising concern for cup instability. Open reduction and internal fixation (ORIF) was performed in the supine position through a lateral rectus abdominis approach (LRAA). Intraoperative direct visualization and fluoroscopy confirmed a well-fixed, osseointegrated acetabular cup, which was therefore retained. The anterior and posterior columns and quadrilateral surface were reconstructed using two contoured reconstruction plates, with careful screw trajectory planning to avoid the cup. Conclusion: For traumatic periprosthetic both-column acetabular fractures after THA, intraoperative assessment of acetabular component stability is pivotal. When the cup is stable, LRAA can provide direct intrapelvic exposure enabling anatomic reduction and robust buttress fixation of the quadrilateral surface while avoiding revision arthroplasty.