Quality of Reduction of Displaced Intra-articular Calcaneal Fractures Using a Sinus Tarsi Versus Extensile Lateral Approach

Objective: To evaluate the difference in the quality of fracture reduction between the sinus tarsi approach (STA) and extensile lateral approach (ELA) using postoperative Computed Tomography (CT) scans in displaced intra-articular calcaneal fractures (DIACFs). Design: Retrospective. Setting: Level 1 and level 2 academic centers. Patients: Consecutive patients undergoing operative fixation of DIACFs with postoperative CT scans and standard radiographs. Methods: Patients were identified based on Current Procedural Terminology code and chart review. All operative calcaneal fractures treated between 2012 and 2018 by fellowship-trained orthopaedic trauma surgeons were evaluated. Those with both postoperative CT scans and radiographs were included. Exclusion criteria included extra-articular fractures, malunions, percutaneous fixation, ORIF and primary fusion, and those patients without a postoperative CT scan. The Sanders classification was used. Cases were divided into 2 groups based on ELA versus STA. Bohler angle and Gissane angle were evaluated on plain radiographs. CT reduction quality grading included articular step off/gap within the posterior facet, and varus angulation of the tuberosity: CT reduction grading included: excellent (E): no gap, no step, and no angulation; good (G): <1 mm step, <5 mm gap, and/or <5 degrees of angulation, fair (F): 1-3 mm step, 5-10 mm gap, and/or 5-15 degrees angulation; and poor (P): >3 mm step, >10 mm gap, and/or >15 degrees angulation. Results: Seventy-seven patients with 83 fractures were included. Average age was 42 years (range, 18-74 years), with 57 men. Four fractures were open. There were 37 Sanders II and 46 Sanders III fractures; 36 fractures were fixed using the STA, whereas 47 used the ELA. Average days to surgery were 5 for STA and 14 for ELA (P < 0.001). A normal Bohler angle was achieved more often with the ELA (91.5%) than with STA (77.8%) (P < 0.001). There was no difference by approach for Gissane angle (P = 0.5). ELA had better overall reduction quality (P = 0.02). For Sanders II, there was no difference in reduction quality with STA versus ELA (P = 0.51). For Sanders III, ELA trended toward better reduction quality (P = 0.06). Conclusions: The ELA had a better overall reduction of Bohler angle on plain radiographs and of the posterior facet and tuberosity on postoperative CT scans. For Sanders type II DIACFs, there was no difference between STA and ELA. Importantly, for Sanders III DIACFs, ELA trended toward better reduction quality. In addition to fracture reduction, surgeon learning curve, early wound complications, and long-term outcomes must be considered in future studies comparing the ELA and STA.