The Diagnostic Accuracy of Böhler’s Angle in Fractures of the Calcaneus

• Published in: The Journal of emergency medicine Vol. 45; no. 6; pp. 879 - 884
• Main Authors: Isaacs, Joseph D., MD, Baba, Mohammed, MD, Huang, Phil, MD, Symes, Michael, MD, Guzman, Maurice, MD, Nandapalan, Haren, MD, Moopanar, Terence, MD, Marchalleck, Steve, MD, Szomor, Zoltan, PhD, MD, FRACS
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2013
• Subjects: Adult; Böhler; Böhler 's angle; calcaneus; Calcaneus - injuries; diagnostic accuracy; Emergency; Female; fracture; Fractures, Bone - diagnostic imaging; Humans; Male; Middle Aged; orthopedic surgery; os calcis; Predictive Value of Tests; Radiography; Retrospective Studies; screening tool; Sensitivity and Specificity; Böhler 's angle; diagnostic accuracy; calcaneus; orthopedic surgery; os calcis; screening tool; Böhler; fracture
• ISSN: 0736-4679; 2352-5029
• DOI: 10.1016/j.jemermed.2013.04.055

Abstract Background Böhler's historical tuber-joint angle of the calcaneus has been used since 1931. Surprisingly, there is a paucity of literature on its use. Objectives To confirm the normal range for Böhler's angle and determine the angle with the highest accuracy in the diagnosis of calcaneal fractures. Methods A retrospective cohort study was performed. The study cohort comprised 424 patients spanning a 5-year period from April 2005 to March 2010. Böhler's angle was measured by two independent observers on lateral x-ray study using the digital angle tool from the Picture Archival and Communication System. Data were analyzed using Stata 8 statistical software package. Results The mean Böhler's angle in patients without calcaneal fracture was 29.4°. In this group there was no difference in Böhler's angle between male and female patients, left and right feet, or across age. In those patients with calcaneal fractures, a Böhler's angle below 25° was moderately predictive of calcaneal fracture (sensitivity = 100%, specificity = 82%), an angle below 23° was highly predictive of calcaneal fracture (sensitivity = 100%, specificity = 89%), and an angle below 21° was strongly suggestive of calcaneal fracture (sensitivity = 99%, specificity = 99%). A Böhler's angle of ≤ 20° had the highest diagnostic accuracy. Conclusion A Böhler's angle of 20° or less is highly accurate in determining the presence or absence of calcaneal fracture. Böhler’s angle serves as a useful screening tool in fracture diagnosis.