Nerve proximity during bicortical drilling for subpectoral biceps tenodesis: a cadaveric study.

Purpose: The long head of the biceps can develop tendonitis and tendinosis, which can lead to pain in the bicipital groove. The use of bicortical button fixation allows for a smaller defect in the humerus compared with tenodesis screws, reducing the risk of fracture. Our objective is to evaluate the exit location of our bicortical button and its relation to relevant posterior nervous structures.

Methods: We performed anatomic dissection of 6 fresh-frozen cadaveric upper extremities. At the level of the inferior border of the pectoralis major tendon, the musculotendinous junction of the long head of the biceps was identified. At the base of the bicipital groove, a 3.2-mm guidewire was advanced perpendicularly through both the anterior and posterior cortex. Posteriorly, the radial and axillary nerves were carefully dissected. For each dissection, we recorded the closest distance from the posterior cortical hole created by our drill to both the axillary and radial nerves using digital calipers.

Results: The mean distance from the axillary nerve to the posterior drill hole was 25.1 mm (95% confidence interval, 21.6 to 28.6 mm). The mean distance from the radial nerve to the posterior drill hole was 30.3 mm (95% confidence interval, 27.2 to 33.4 mm).

Conclusions: With placement of the tenodesis at the inferior aspect of the bicipital groove in conjunction with the musculotendinous junction, open subpectoral tenodesis of the long head of the biceps can be performed using bicortical button fixation without risk to the posterior nervous structures.

Clinical Relevance: This cadaveric study suggests that posterior proximal humerus nervous structures can be avoided with proper tenodesis placement.