The Proximity of the Axillary Nerve During Keyhole Tenodesis of the Long Head of the Biceps Tendon: A Cadaveric Study.

Background: Over time, surgical management for conditions involving the long head of the biceps tendon (LHBT) has evolved. Some techniques, such as keyhole tenodesis proposes bicortical drilling, however, carries an axillary nerve injury risk. The goal of our cadaveric study was to see if we could keep a safe zone between the point of exit of keyhole tenodesis of biceps and axillary nerve.

Methodology: The study was performed on ten shoulders from five fresh frozen cadavers. Between the lower border of the transverse humeral ligament (THL) and the superior margin of the pectoralis major insertion at the lowest limit of the bicipital groove, a beath pin was driven through with the help of the modified tip aimer tibial jig procured from the anterior cruciate ligament reconstruction (ACL) set, which was fixed at an arc of 45°. The distance between the axillary nerve and beath pin at the exit point was measured.

Results: The biceps tendon musculotendinous junction was followed all the way to the inferiorly and biceps tendon was found in the groove. The average distance from the axillary nerve to the exit point of the beath pin was 17.7 mm (range 14.4-20.9 mm, 95% CI).

Conclusion: The axillary nerve is not injured during bicortical drilling when keyhole tenodesis of biceps is performed at the distal limit of the groove of biceps. The area in the biciptal groove between inferior margin of THL and superior border of pectoralis major insertion is safe area for biceps tenodesis.