Position of Brachial Artery with Changing Elbow Flexion: Implications for Arthroscopy (SS-49)

Abstract

<h3>Introduction</h3> Arthroscopy of the anterior compartment of the elbow may be performed at various flexion angles depending on the procedure. Since the brachial artery courses near the anterior surface of the distal humerus and proximal ulna, it is important to recognize how the vascular anatomy is related to elbow position in order to minimize risk of arterial injury. The purpose of this study was to determine how close the brachial artery was located to the distal humerus and proximal ulna with varying elbow flexion. <h3>Methods</h3> Eleven fresh-frozen cadaveric elbows were obtained and superficial muscular dissection was performed to identify the brachial artery proximal and anterior to its crossing the elbow. Barium was injected through the lumen of the artery and lateral images of the elbow in the sagittal plane were obtained with a fluoroscan at 5 different elbow flexion angles (0, 30, 60, 90, and 110 degrees). Digital software was used for 2 measurements: 1) the closest distance of the brachial artery from the anterior surface of the distal humerus (at the coronoid fossa), and 2) the closest distance of the brachial artery from the anterior surface of the ulna (15 mm distal to the tip of the coronoid). One-way ANOVA for repeated measures was used to compare the mean distances for each flexion group within each measurement group. A coronal image in full extension was also obtained to examine the medial-lateral course of the brachial artery as it passed the coronoid and fossa. <h3>Results</h3> The mean distances of the brachial artery from the distal humerus for each flexion angle were 12.2 mm, 17.7 mm, 21.2 mm, 21.7 mm, and 21.2 mm at 0, 30, 60, 90, and 110 degrees, respectively. The mean distance away from the distal humerus significantly increased with increasing flexion up to 60 degrees (p<0.001). The mean distances of the brachial artery from the coronoid at each flexion angle were 16.7 mm, 18.7 mm, 21.4 mm, 22.8 mm, and 24.7 mm at 0, 30, 60, 90, and 110 degrees, respectively. The mean distance away from the coronoid significantly increased with increasing flexion (p<0.002). Further, the brachial artery traversed lateral to the coronoid and fossa in 10 of 11 specimens (mean, 4.5 mm lateral). <h3>Conclusion</h3> The results of this study suggest that the brachial artery is located further away from the distal humerus (at the coronoid fossa) and proximal ulna (at the coronoid) with increasing elbow flexion and slightly laterally in the coronal plane. These anatomic landmarks can be used as references during elbow positioning at arthroscopy in order to reduce the risk of brachial artery injury.