Mapping the axillary nerve within the deltoid muscle

Area of Science:

• Anatomy
• Surgical Anatomy
• Neuroscience

Background:

• Axillary nerve injury occurs in 6% of brachial plexus injuries.
• Accurate anatomical descriptions are vital to prevent iatrogenic damage.
• Variations in axillary nerve branching within the deltoid muscle require detailed study.

Purpose of the Study:

• To investigate the anatomical variations of the axillary nerve within the deltoid muscle.
• To provide detailed descriptions of axillary nerve branching patterns.
• To aid in reducing iatrogenic injuries during surgical procedures.

Main Methods:

• Dissection of 50 human cadavers (100 nerve specimens).
• Identification and measurement of anterior and posterior branches of the axillary nerve.
• Analysis of nerve origin, termination, and branching patterns within the deltoid muscle.

Main Results:

• The axillary nerve split within the quadrangular space in 65% of cases and within the deltoid muscle in 35%.
• The posterior branch consistently supplied the teres minor and superior lateral brachial cutaneous nerve.
• The middle deltoid received dual innervation in 38% of cases, and the posterior deltoid in 8%.

Conclusions:

• Significant anatomical variations exist in the axillary nerve's intra-deltoid branching.
• Detailed anatomical knowledge is essential for surgeons to minimize iatrogenic axillary nerve injury.
• Understanding these variations can improve surgical outcomes and patient safety.