Acetabular Posterior Wall Morphology. A CT-based Method to Distinguish Two Acetabular Posterior Wall Types

Background: The anatomy of the posterior wall of the acetabulum is important for the hip stability. We wanted to know whether differences can be observed. Material and methods: On lateral 3D pelvic CT reconstruction of the pelvis two types were identified. On axial CT-images acetabular angles were determined. Results: We observed 35 type I acetabular and 61 type II acetabular. Posterior acetabular sector angle was 114 degrees in type I and 94 degrees in type II acetabular (p < 0.01). At an cut-off angle of 100 degrees we could predict the type of acetabulum. Conclusions: We could describe reference values for the posterior wall to distinguish two morphological types.