English

Abstract

Abstract To investigate the radiographic anatomy characteristics of the bones in fractured calcaneus by using tangential X-rays. Fifty-seven patients (114 sides) with normal calcaneus and thirty patients (42 sides) with fractured calcaneus were radiographed along the line connecting the midpoint of the 4(th) and 5(th) metatarsal heads with the lateral margin of the corpus calcanei. The anatomy characteristics of the calcaneus on the tangential X-rays view including radius and fractal geometry were analysed. On a tangential X-ray view of the fractured calcaneus, the projection of sustentaculum tali resembled a duck beak, which was just under the middle facet of the talocalcaneal joint. The corpus calcanei was oval and was just under the talocalcaneal joint articular surface. The lateral calcaneal wall did not exceed the vertical line extending from the medial of the lateral malleolar fossa (the Z-W line). From the scan, fractured calcaneus seemed to widen as its lateral wall crossed the Z-W line. The longitudinal axis of this oval-shaped projection was 3.52 ± 0.41 cm (a), the horizontal axis was 2.56 ± 0.28 cm (b) and the a/b ratio was 1.40 ± 0.11. In normal calcaneus, the a/b ratio was higher than 1.40, and the differences of the values in these two groups were significant. Therefore, the a/b ratio of the calcaneus' oval-shaped projection can be used to evaluate the degree of its deformity after fracture. These results demonstrated that tangential X-ray view of the calcaneus can be used to evaluate its radiographic anatomy and to measure the radii of oval shape.