This cadaveric study of 19 fresh-frozen shoulders maps the surgical anatomy of the posterior branch of the axillary nerve. It defines where the nerve to the teres minor and the superior-lateral brachial cutaneous nerve arise and how they relate to the glenoid, capsule, and deltoid. The goal is to guide safe posterior and arthroscopic shoulder surgery.
When you plan posteroinferior capsular plication or thermal shrinkage, remember the posterior branch of the axillary nerve sits directly on the capsule at the glenoid rim. Because there are no tethering articular branches, an open surgeon can lift the nerve off the capsule, but arthroscopically you cannot see it, so posteroinferior capsular work carries real motor risk to the teres minor.
The shared origin of the teres minor motor branch and the lateral deltoid sensory branch gives you a bedside pearl: numbness over the lateral deltoid after posterior shoulder surgery or instability may signal teres minor denervation, not just a benign sensory injury.
For a posterior deltoid-splitting approach, keep dissection within about 50 mm below the posterolateral corner of the acromion to protect deltoid motor supply. The teres minor matters most when the superior cuff is torn or the suprascapular nerve is out, so preserving its innervation is not trivial.
This cadaveric study of 19 fresh-frozen shoulders maps the surgical anatomy of the posterior branch of the axillary nerve. It defines where the nerve to the teres minor and the superior-lateral brachial cutaneous nerve arise and how they relate to the glenoid, capsule, and deltoid. The goal is to guide safe posterior and arthroscopic shoulder surgery.
When you plan posteroinferior capsular plication or thermal shrinkage, remember the posterior branch of the axillary nerve sits directly on the capsule at the glenoid rim. Because there are no tethering articular branches, an open surgeon can lift the nerve off the capsule, but arthroscopically you cannot see it, so posteroinferior capsular work carries real motor risk to the teres minor.
The shared origin of the teres minor motor branch and the lateral deltoid sensory branch gives you a bedside pearl: numbness over the lateral deltoid after posterior shoulder surgery or instability may signal teres minor denervation, not just a benign sensory injury.
For a posterior deltoid-splitting approach, keep dissection within about 50 mm below the posterolateral corner of the acromion to protect deltoid motor supply. The teres minor matters most when the superior cuff is torn or the suprascapular nerve is out, so preserving its innervation is not trivial.