Three-dimensional morphological characteristics of calcaneal lateral facet and calcaneal anatomical plate

Abstract

Objective To explore the three-dimensional (3-D) morphological characteristics of the calcaneal lateral facet using CT image post-processing technique and the match of the calcaneal anatomic plate to the characteristics. Methods We collected the thin-slice CT data of 100 patients with normal calcaneus (50 males and 50 females) who had undergone 16-slice spiral CT scanning from December 2009 to January 2012.Surface shaded display (SSD) technique was used to reconstruct 3-D images of the calcaneus and its associated bony structures.The calcaneus was isolated by 3-D topological narrow division technique.The parameters of point,line and surface concerning the calcaneal lateral facet were measured.The fixations with conventional calcaneal anatomic plates were simulated and matches of the plates to the 3-D morphology of the calcaneus were observed. Results The mean length and height of the lateral facet,the mean height of the anterior part and the mean length of the posterior articular surface were respectively 80.4 ±3.8 mm,45.4 ± 3.0 mm,24.2 ± 2.2 mm and 29.3 ± 3.1 mm in male group and 69.5 ± 4.2 mm,36.2 ± 3.1 mm,21.1 ± 1.1 mm and 23.5 ±2.5 mm in female group.There were significant differences between the 2 groups in all the above parameters ( P ＜ 0.05).There was no significant difference in the length of anterior part between the 2 groups (male:21.3 ± 1.5 mm versus female:21.1 ± 1.1 mm) ( P ＞ 0.05).The Gissane's angle and the B(6)hler's angle were respectively 128.4° ± 11.7° and 51.2° ± 6.1 ° in male group while 124.3° ±8.6° and 58.3° ± 6.7° in female group,with significant differences between the 2 groups ( P ＜ 0.05).Match observations revealed that the plates of all kinds attached the bon facet well but some plates still needed cutting or bending. Conclusions The present study provides a series of scientific and objective data for operative protocols planned before anatomic reduction of the calcaneal fractures and orthomorphia for the malunion.A better understanding of how the calcaneal anatomic plate matches the calcaneal morphology may help orthopoedists select and locate the implant correctly. Key words: Calcaneus; Imaging, three-dimensional; Tomography, X-ray computed; Bone plates