Böhler's Angle-Comparison Between the pre- and Postoperative in Displaced Intra-Articular Calcaneal Fractures

Objective  To compare pre- and postoperative variation of radiographic measurements of the Böhler angle (BA) in fractures with two types of deviations: severe and moderate. Methods  Pre- and postoperative BAs in 31 calcaneal fracture radiographs were retrospectively analyzed. A total of 4 patients were female (6.5%) and 26 were male (83.9%), with age ranging from 23 to 72 years old, and a mean age of 44.5 years old. Results  The results show that the postoperative BA was significantly larger than the preoperative BA ( p  = 0.000). At the intraevaluator and overall assessments, the postoperative BA was, on average, 10.6° higher than the preoperative measure. The postoperative angle was, on average, 108% higher than the preoperative angle. In the global assessment, the agreement between evaluators was excellent, both regarding the estimated point value (0.98) and the intraclass correlation (ICC) confidence interval (CI). Conclusion  In the global analysis, the postoperative BAs were, on average, significantly higher than the preoperative measurements. The farther from the normal range (20° to 40°) the preoperative angle is, the greater the difference after the surgery. When the preoperative angle was normal, the postoperative angle was, on average, 1.28 times the preoperative measurement. If the preoperative BA was abnormal, the postoperative angle was, on average, 17.3 times the preoperative measurement. It was demonstrated that more severe fractures present better anatomic results when compared with moderate fractures. The present study also confirms a good interobserver correlation for the BA.