Predicting loss of height in surgically treated displaced intra-articular fractures of the calcaneus

The goal of calcaneal fracture surgery is to restore its anatomy and good foot function. However, loss of height of the subtalar joint can occur post-operatively, as expressed by a decrease in Böhler's angle (BA). The aim of this study was to identify potential factors associated with a post-operative decrease in BA.All consecutive adult patients treated with open reduction and internal fixation (ORIF) by an extended lateral approach (ELA) between 2000 and 2013 were retrospectively included. Primary outcome was the occurrence of a calcaneal collapse, defined as a postoperative decrease of ≥10° in BA. The BA was measured pre-operatively, directly following surgery and at one year follow-up. Patient characteristics (body mass index, diabetes mellitus, smoking/alcohol/substance abuse, American Society of Anaesthesiologist classification), fracture classification and treatment characteristics: per-operative increase in BA and occurrence of post-operative wound infection (POWI) were collected.A total of 262 patients with 276 calcaneal fractures were included. A calcaneal collapse occurred in 46 cases (17%). The median preoperative BA, per-operative increase in BA and post-operative decrease in BA were, respectively, 2°, 27° and 4°. A calcaneal collapse was seen more often following a per-operative increase of >25° in BA, but no significant association was found (p = 0.056). Uni- and multivariate analysis showed that patients with substance abuse and those with POWI had significantly more calcaneal collapse (p < 0.05). No association was found between substance abuse and the occurrence of POWI (p = 0.293).In nearly one in six patients with an intra-articular calcaneal fracture treated with ORIF by an ELA, a post-operative collapse of ≥10° was found during follow-up. Calcaneal collapse was correlated with the occurrence of a POWI and substance abuse.