Acetabular fractures: anatomy, evaluation, management

Overview

This StatPearls review by Hoge and Chauvin, last updated in March 2022, covers the evaluation, diagnosis and treatment of acetabular fractures. They occur mainly in young people after high-velocity trauma, at an incidence of about 3 per 100,000 since seatbelt use became mandatory. Fractures from falls of less than 10 feet are increasing, probably because of osteopenia and osteoporosis. Letournel and Judet's work remains the gold standard, and one of the main recent advances is percutaneous fixation of selected fracture types.

Anatomy and associated injuries

The acetabulum divides into an anterior and a posterior column, and the articular surface can be pictured as an inverted Y attached to the sacroiliac joint by the sciatic buttress. These are often high-energy injuries: in one large series half of the patients had associated injuries, most often of the extremities, followed by head, chest and nerve injuries. Even isolated fractures may need blood transfusion, and sciatic nerve injury, usually of the peroneal division with foot drop, must be checked on admission.

Evaluation and classification

Assessment follows standard trauma principles. Plain films (AP pelvis with obturator oblique and iliac oblique Judet views) come first, and six radiographic landmarks help to classify the pattern. CT is more precise and is often needed because of associated injuries. Stress views can test hip stability in posterior wall fracture-dislocations. The Letournel system divides fractures into five elementary types (posterior wall, posterior column, anterior wall, anterior column, transverse) and five associated patterns, of which both-column fractures are the most common.

Management

Most acetabular fractures need open reduction and internal fixation, usually 3 to 5 days after injury, since delays beyond 3 weeks are linked to poorer outcomes. Non-operative treatment suits stable, congruent fractures that spare the superior dome, and follows protected partial weight bearing with weekly radiographs for the first 4 weeks. Emergency surgery is indicated for irreducible or recurrently dislocating hips, progressive sciatic deficit, vascular injury, open fractures and ipsilateral femoral neck fractures. The main approaches are the Kocher-Langenbeck, ilioinguinal and iliofemoral.

Complications and outcome

The quality of reduction is the main determinant of late arthritis, with a goal of within 1 mm. Other complications include infection (about 5%), nerve injury, venous thromboembolism and heterotopic ossification, which is prevented with radiation or indomethacin after extended or posterior approaches. Prognosis is worst for T-type fractures, and findings at one year are the most reliable guide.