[CT-based classification aid for acetabular fractures: evaluation and clinical testing].

BACKGROUND

The basis for the classification of acetabular fractures depends on accurate radiological diagnostics. The use of conventional X-rays alone implicates a low intrapersonal reproducibility and interpersonal reliability. By applying computed tomography (CT) at an early stage in the emergency room, the typical diagonal X-rays of ala and obturator, on which the classification is based, are no longer recommended. The aim of this study was to develop a new reliable classification system based on standardized CT slices according to the system of Judet and Letournel without using diagonal X-rays.

MATERIALS AND METHODS

In this study 12 select cases with acetabular fractures were peer reviewed. In each case eight characteristic CT slices (five axial, two coronal and one sagittal) were selected as well as the conventional anteroposterior X-ray of the pelvis. All cases were peer reviewed by 14 members of the "AG Becken" (working group pelvis). The classification of the acetabular fractures was based on Judet and Letournel and the results were compared with the reference classification. The results were scaled according to differences to the original classification and the relevance to the approach as well as the medical qualification of the member.

RESULTS

A total of 167 out of 168 possible classifications were conducted, 90 cases (54 %) were in accordance with the reference classification. In 69 cases (41 %) the outcome was different, which would have had no influence on the choice of the surgical approach. A wrong classification was present eight times (5 %). According to the medical qualification status the senior physicians were right in 54%, the residents in 53 %. Within the group of senior physicians 7.5 % of the classifications were completely wrong and 93 % of the participating members would have preferred to have more CT slices.

CONCLUSION

The CT-based classification developed represents an adaption to the current standard of diagnostics of acetabular fractures and represents a step towards simplification of the classification. It is suitable to estimate the correct surgical approach and the behavior of the fracture. For an accurate classification and the association to one of the fracture types in the system of Judet and Letournel more slices and 3D reconstructions (MPR) are necessary.