Value of 3D Reconstructions of CT Scans for Calcaneal Fracture Assessment

Abstract

Background: The interpretation of CT scans for the evaluation of calcaneal fractures is difficult. Three-dimensional (3D) reconstruction (volume rendering technique [VRT]) has been valuable in the evaluation of irregularly shaped bones. However, their value for the analysis of calcaneal fractures is still debated. Therefore, the objective of this study was to assess the effect of additional use of 3D CTs in calcaneal fractures.

Methods: In a prospective multicenter study, the CT data set of 5 different fractures was presented to 57 evaluators. First, the participating surgeons were asked to assess the fractures on the basis of axial, coronal, and sagittal reconstructions using a multiple-choice questionnaire. Second, 3D reconstructions (VRT) were presented. The CT scans were validated by the intraoperative findings and the results were compared to the model solution of 3 foot and ankle surgeons. Intra- and interrater reliabilities were calculated.

Results: The proportion of intraobserver agreement was 82%, with Cohen kappa of κ = 0.748 (P < .001). Interrater agreement varied between 0.772 (P = .006) for the assessment of concomitant fractures and 0.987 (P < .001) for the suggested approach. The evaluation of several items improved after presentation of the 3D CTs (Cochrane Q test, P < .001). The benefit of 3D imaging was higher in inexperienced surgeons and complex fractures (Friedman test P < .001).

Conclusion: The evaluation of CT scans of calcaneal fractures was improved by the additional use of 3D images (VRT).

Level of evidence: Level II, prospective comparative study.

Keywords: 3D reconstruction; CT scan; calcaneal fracture; reliability; validity; volume rendering technique.