Three-dimensional mapping study of pure transverse acetabular fractures

Area of Science:

• Orthopedic Surgery
• Radiology
• Biomechanics

Background:

• Pure transverse acetabular fractures are complex injuries requiring detailed analysis.
• Understanding fracture line morphology is crucial for treatment planning and outcomes.

Purpose of the Study:

• To map and quantitatively analyze the morphological characteristics, location, and frequency of pure transverse acetabular fracture lines.

Main Methods:

• Retrospective analysis of computed tomography (CT) data from 49 transverse acetabular fractures.
• 3D reconstruction and manual reduction of fracture fragments.
• Fracture lines mapped onto a 3D hemipelvis template to create 3D fracture maps and heatmaps.
• Classification into infratectal (62-B1.1), juxtatectal (62-B1.2), and transtectal (62-B1.3) types (AO/OTA).

Main Results:

• Analysis of 49 fractures (32 male, 17 female; mean age 42 years).
• Anterior rim fracture angles averaged 70.0°, with 81.6% between 63°-80°.
• Heatmap analysis revealed 'hot zones' on the superior cotyloid fossa and narrowed region, and a 'cold zone' on the inferior articular surface.
• Significant differences in posterior rim fracture angle and posterior height among subtypes (P < 0.01).
• Posterior intra-articular fracture lines were longer than anterior ones in types 62-B1.1 and 62-B1.2 (P < 0.01).

Conclusions:

• Anterior rim fracture lines concentrate on the narrowed zone; posterior lines are diffusely distributed.
• Intra-articular fracture lines predominantly involve the superior and middle thirds of the joint surface.
• Weight-bearing dome involvement converges on the posterior acetabular roof.