We attempt to evaluate the significance of calcaneal posterior tuberosity fragment reduction when treated with surgical open reduction in displaced intra-articular calcaneal fractures.

A total of 90 patients with displaced intra-articular calcaneal fracture, between January 2010 and December 2015, treated with open reduction and internal fixation were enrolled in this study. At postoperative 3 months, we evaluated the reduction state of calcaneal posterior tuberosity fragment by measuring the degree of lateral displacement of the posterior tuberosity fragment on the calcaneal axial view. Moreover, we also evaluated the difference in the calcaneal length and height with the uninjured side on the lateral view of both sides. In addition, we estimated the reduction state of the posterior facet by measuring the degree of gap and step-off on the semi-coronal view of postoperative computed tomography and estimated the restoration of calcaneal angle by measuring the difference in Böhler's and Gissane angle with the uninjured side on the lateral view of both sides.

The correlation coefficient with 3 components for evaluating the reduction state of posterior tuberosity fragment and gap and step-off of posterior facet was r=0.538, 0.467, r=0.505, 0.456, r=0.518, and 0.493, respectively, and restoration of Böhler's and Gissane angle was r=0.647, 0.579, r=0.684, 0.630, r=0.670, and 0.628, respectively. The relationship of each component shows a significant correlation as all p-values were <0.01.

The precise reduction of calcaneal posterior tuberosity fragment developed by the primary fracture line was considered as an important process of anatomical reduction of calcaneal body, including the posterior facet and calcaneal angle restoration.