The surgical neck of the humerus is a bony constriction at the proximal end of shaft of humerus. It is situated distal to the
greater tubercle
The greater tubercle of the humerus is the outward part the upper end of that bone, adjacent to the large rounded prominence of the humerus head. It provides attachment points for the supraspinatus, infraspinatus, and teres minor muscles, thre ...
and
lesser tubercle
The lesser tubercle of the humerus, although smaller, is more prominent than the greater tubercle: it is situated in front, and is directed medially and anteriorly.
The projection of the lesser tubercle is anterior from the junction that is found ...
, and proximal to the
deltoid tuberosity
In human anatomy, the deltoid tuberosity is a rough, triangular area on the anterolateral (front-side) surface of the middle of the humerus. It is a site of attachment of deltoid muscle.
Structure
Variation
The deltoid tuberosity has been re ...
.
Clinical significance
The surgical neck is much more frequently fractured than the
anatomical neck of the humerus
The anatomical neck of the humerus is obliquely directed, forming an obtuse angle with the body of the humerus. It represents the fused epiphyseal plate.
Structure
The anatomical neck divides the head of the humerus from the greater and less ...
. This type of fracture takes place when the humerus is forced in one direction while the joint capsule and the rotator cuff muscles remain intact. A fracture in this area is most likely to cause damage to the
axillary nerve
The axillary nerve or the circumflex nerve is a nerve of the human body, that originates from the brachial plexus (upper trunk, posterior division, posterior cord) at the level of the axilla (armpit) and carries nerve fibers from C5 and C6. The a ...
and
posterior circumflex humeral artery
The posterior humeral circumflex artery (posterior circumflex artery, posterior circumflex humeral artery) arises from the third part of axillary artery at the lower border of the subscapularis, and runs posteriorly with the axillary nerve through ...
. Damage to the axillary nerve affects function of the
teres minor
The teres minor (Latin ''teres'' meaning 'rounded') is a narrow, elongated muscle of the rotator cuff. The muscle originates from the lateral border and adjacent posterior surface of the corresponding right or left scapula and inserts at both the ...
and
deltoid muscles, resulting in loss of abduction of arm (from 15-90 degrees), weak flexion, extension, and rotation of shoulder as well as loss of sensation of the skin over a small part of the lateral shoulder.
Additional images
File:Neck-of-Humerus.jpg, The difference between anatomical neck and surgical neck of the humerus
File:Illustrations of Dissections Plate 05 shoulder.jpg, Posterior view of the humerus showing the axillary nerve and posterior circumflex humeral artery at the surgical neck.
See also
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Quadrangular space
The quadrangular space, also known as the quadrilateral space f Velpeau'' and the foramen humerotricipitale, is one of the three spaces in the axillary space. The other two spaces are: triangular space and triangular interval.
Structure
The q ...
*
Anatomical neck of the humerus
The anatomical neck of the humerus is obliquely directed, forming an obtuse angle with the body of the humerus. It represents the fused epiphyseal plate.
Structure
The anatomical neck divides the head of the humerus from the greater and less ...
References
External links
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Humerus
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