The Distance between the Pectoralis Major Tendon Insertion and the Top of the Humeral Head is a Reliable Landmark: An Anatomic Study

Abstract

<b>Purpose</b> This study aimed to analyze the distance between the superior edge of the pectoralis major and the top of the humeral head and evaluate whether this distance is a consistent measurement. <b>Methods</b> Twenty-two shoulders in eleven cadavers were dissected and the attachment of the pectoralis major tendon was preserved. Two distances were recorded with the help of digital vernier caliper: the distance between the upper edge of pectoralis major and tangent to the top of humeral head (PM-T) and the distance between the superomedial tip of greater tuberosity (GT) and the upper edge of the pectoralis major tendon (PM-G; ± standard error of the means). <b>Results</b> The mean PM-T distance was 53.8 mm (±0.8 mm) and the mean PM-G distance was 46.8 mm (±0.9 mm). The distance between the top of humeral head and tip of the GT was 7 mm. The PM-T distance was a significant outlier in three shoulders as it inserted high on the humerus. <b>Conclusion</b> We can conclude that the PM-T and PM-G distances were a consistent measurement. <b>Clinical Relevance</b> The distance between the pectoralis major tendon and top of the humeral head was measured in this study as a reliable method that can be used intraoperatively to decide the height of the humerus prosthesis in comminuted fractures of the proximal humerus.