Radiographic assessment of calcaneal fractures; A new approach to Böhler’s angle using computed tomography

Background

Böhler’s angle (BA) is used for identifying calcaneal fractures and evaluating calcaneal collapse after reconstruction. This study investigates whether it is possible to determine BA with the help of Computed Tomography (CT).

Methods

A retrospective study was performed to compare the BA on conventional radiograph (Gold Standard, GS) versus measurements on CT. Two groups were studied: one group consisted of 11 subjects with a diagnosed calcaneal fracture, the other group of 11 subjects with a fracture of the lower extremities but no calcaneal fracture. A lateral Böhler angle (LBA), central Böhler angle (CBA) and a medial Böhler angle (MBA) were defined on CT. Furthermore, BA was reconstructed out of a 3D reconstruction (3DBA).

Results

CBA approached the GS with a mean difference of 3.78° (95 %CI: 2.82–4.75) with no significant difference in variance (p = 1.000). 3DBA approached the GS with a mean difference of 2.14° (95 %CI: 1.57–2.70) with a significant difference in variance (p = 0.014). No relevant correlations were found between LBA/MBA and the GS. ICC between raters was considered as good or excellent for both CBA and 3DBA.

Conclusion

Giving the high accuracy and better capability to visualize the anatomy in the case of severe injury, measuring BA on 3D reconstruction is a suggested alternative to the traditional technique.

Level of evidence

III, Retrospective