Proximity of Axillary Nerve During Cortical Button Repair of Pectoralis Major Tendon Rupture

Abstract

Background Rupture of the pectoralis major (PM) tendon is a rare but severe injury. Several techniques have been described for PM fixation, including a transosseus technique, placing cortical buttons at the superior, middle and inferior PM tendon insertion points. The present cadaveric study investigates the proximity of the posterior branch of the axillary nerve to the drill positions for transosseus PM tendon repair. Methods Twelve cadaveric shoulders were used. The axillary nerve was marked during a preparatory dissection. Drills were passed through the humerus at the superior, middle and inferior insertions of the PM tendon and the drill bits were left in situ. The distance between these and each axillary nerve was measured using computed tomography. Results The superior drill position was in closest proximity to the axillary nerve (three-dimensional distance range 0-18.01 mm, mean 10.74 mm, 95% confidence interval 7.24 mm to 14.24 mm). The middle PM insertion point was also very close to the nerve. Conclusions Caution should be used when performing bicortical drilling of the humerus, especially when drilling at the superior border of the PM insertion. We describe 'safe' and 'danger' zones for the positioning of cortical buttons through the humerus reflecting the risk posed to the axillary nerve.

Insertion anatomy of the pectoralis major tendon

“…13 A knowledge of the insertion anatomy will avoid any complications such as posterior axillary nerve injury because a recent study described that the nerve is at risk and at close proximity when the drill is passed at the superior border of the tendon. 14 Pectoralis major tendon insertion has also been found to be an important factor in deciding the height of the…”