Fracture lines and comminution zones in acetabular fractures based on three dimensional computed tomography.

Purpose: To characterize the fracture patterns of acetabular fractures and create fracture maps and comminution zones based on three-dimensional (3D) computed tomography (CT) images.

Methods: Sixty-eight computed tomography images of 67 patients (47 male [70.1%] and 20 female [29.9%], mean age: 45.2 ± 17.2 [range, 18-85 years] with the diagnosis of intra-articular acetabulum fracture were analyzed. Individual fracture lines were drawn and superimposed to a healthy acetabular template according to Judet-Letournel and simplified fracture classification systems. Fracture line, comminution zone, and heat maps were created using the computed tomography mapping technique.

Results: Fracture lines were distributed mainly in a horizontal and oblique orientation, which concentrated in the anteroinferior part of the joint in anterior fractures. Posterior fractures mostly had an oblique orientation, which lied between the acetabular dome and middle part of the posterior wall. In complex fractures, fracture lines were concentrated just above the cotyloid fossa, acetabular dome, and posterosuperior part of the acetabulum. The most common comminuted zones were around the central area of the articular surface and the anterior wall in anterior fractures, between the cotyloid fossa and dome in complex fractures, and the upper half posterior wall.

Conclusion: Fracture patterns and comminution zones of acetabular fractures displayed certain characteristics. Some areas had higher comminution zones, and some areas remained intact in repeatable fracture patterns. These results may help surgeons in fixing acetabular fractures, designing new implants, and placement of acetabular component while performing THA after acetabular fractures.