Acetabular fractures revisited: a new CT-based classification.

The objective of this investigation is to provide a new CT-based classification of acetabular fractures. The axial CT scans of 112 randomly selected acetabular fracture patients admitted to a Level 1 trauma center between January 1998 and December 2000 were analyzed by an experienced orthopedic trauma surgeon and two experienced emergency radiologists. When available, 3D reformatted images were analyzed as well. The fracture pattern for each acetabular fracture with respect to column(s) wall(s) and extension superiorly and/or inferiorly from the acetabulum, when present, was recorded. Fracture comminution was not a defining characteristic. Analysis of the acetabular fracture patterns showed that each fracture fell into one of four broad categories: Category 0--wall only; Category 1--single column; Category 2--both columns, with extension subcategories of (A) no extension, (B) superior extension only, (C) inferior extension only, and (D) both superior and inferior extension; and Category 3--the "floating" acetabulum. The axial CT display of acetabular fracture patterns provides a basis for a classification of acetabular fractures that is simple, unambiguous, readily understood by both radiologists and orthopedic surgeons, and provides clear direction for both diagnosis and surgical treatment planning. Category and subcategory fracture specificity creates a mechanism for intra- and interdepartmental postoperative assessment of any of the individual acetabular fracture types.