Morphometric analysis of safe distance for axillary nerve in deltoid splitting surgeries in South Indian population: A cadaveric study

Abstract

Background: The axillary nerve is one of the important nerve around shoulder which branches off from posterior cord of brachial plexus (C5, C6). Risk of injuring it during shoulder joint surgery or proximal humerus surgeries involving deltoid splitting concern the orthopaedic an the most. To prevent such iatrogenic nerve damage and to improve treatment outcomes, proper anatomical knowledge is of the utmost significance. Axillary nerve exit axilla through the quadrangular space and muscles gets its innervations are deltoid muscle, teres minor, skin over the lateral aspect of shoulder. Materials and Methods: 50 shoulders of 25 adult fresh cadavers were taken for dissection as per standard dissection methods. Position of axillary nerve beneath deltoid muscle from anterolateral edge of acromion process was measured along with the arm length which were tabulated and analysed.Results: The average acromio-axillary nerve distance (AA) was 6.84±0.89 cm and mean arm length 32.19±1.37 cm. AA distance and arm length shows a positive correlation. The minimum acromio-axillary nerve distance was 4.78 cm, which is safe length for deltoid splitting.Conclusion: The safe distance to avoid axillary nerve injury is identified by with a distance of 4.78 cm from tip of acromion process, and depends on arm length. Which will be useful during surgical procedures to avoid injury to the same.