Three dimensional morphological evaluation of calcaneal fracture malunionand its clinical relevance

Abstract

Objective To analyze 3D morphological evaluation of calcaneal fracture malunion based on CT post-processing techniques. Methods Eighteen patients with 19 calcaneal fracture malunion treated in our hospital from May 2010 to June 2015 were analyzed. The average age was 43.3 years (range, 23 to 62 years). There were 12 males (13 feet) and 6 females(6 feet). According to Stephens-Sanders classification, 3 feet were of type Ⅰ, 7 feet type Ⅱ and 9 feet type Ⅲ. Depending on the type of malunion and the preoperative evaluation of 3D morphology, the operation for the calcaneal fracture malunion was performed. The 3D structure of the calcaneus after shaded surface display reconstruction was extracted by interactive and automatic segmentation. The morphological measurements were achieved by means of a 3D measurement method. The data were analyzed using SPSS 18.0 software. The quantitative data were compared by paired t test. Results Making the telephone appointment for outpatient follow-up, all patients were followed up with an average time of 19.1 months. The mean AOFAS ankle-hindfoot score increased from (31.4 ± 6.1) point operatively to (77.4 ± 7.6) at final follow-up. The length of the calcaneal axis, the height of the posterior facet and the length of the posterior facet at final follow-up were significantly restored than those before operation (P<0.001). The mean Bohler′s angle and the mean Gissane′s angle were improved from (17.5° ± 5.6°) and (96.6° ± 9.9°) before operation to (34.2° ± 3.2°) and (124.1° ± 8.9°) at final follow-up respectively (P<0.001). Conclusion Three dimensional morphological evaluation of calcaneus was useful to access the postoperative outcome for calcaneal fracture malunion. The current data will be helpfulfor the reduction of calcaneal malunion. Key words: Calcaneus; Fracture, malunited; Image processing, computer-assisted; Imaging, three-dimensional