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AAAC27 21/5/05 10:45 AM Page 63
Spinoglenoid notch
Suprascapular notch
Spine Head Greater tubercle
Lesser
tubercle Anatomical
Supraspinous
fossa Intertubercular neck
sulcus Surgical
Infraspinous neck
Acromion fossa
Medial border
Deltoid
tuberosity
Spiral
groove

Coracoid process
Superior angle
Acromion Medial
supracondylar
Glenoid fossa ridge Olecranon
fossa
Medial
epicondyle
Subscapular fossa Capitulum
Trochlea
Fig.27.4
Lateral border
Anterior and posterior views of the left humerus

Fig.27.3
Posterior and anterior views of the left scapula

The scapula (Fig. 27.3) • The greater and lesser tubercles provide attachment for the rotator
• The scapula is triangular in shape. It provides an attachment for cuff muscles. The tubercles are separated by the intertubercular sulcus
numerous muscles. in which the long head of biceps tendon courses.
• The glenoid fossa articulates with the humeral head (gleno-humeral • A faint spiral groove is visible on the posterior aspect of the humeral
joint), and the acromion process with the clavicle (acromioclavicular shaft traversing obliquely downwards and laterally. The medial and lat-
joint). eral heads of triceps originate on either side of this groove. The radial
nerve passes between the two heads.
The humerus (Fig. 27.4) • The ulnar nerve winds forwards in a groove behind the medial
• The humeral head consists of one third of a sphere. The rounded head epicondyle.
articulates with the shallow glenoid. This arrangement permits a wide • At the elbow joint: the trochlea articulates with the trochlear notch of
range of shoulder movement. the ulna; and the rounded capitulum with the radial head. The medial
• The anatomical neck separates the head from the greater and lesser border of the trochlea projects inferiorly a little further than the lateral
tubercles. The surgical neck lies below the anatomical neck between border. This accounts for the carrying angle, i.e. the slight lateral angle
the upper end of the humerus and shaft. The axillary nerve and cir- made between the arm and forearm when the elbow is extended.
cumflex vessels wind around the surgical neck of the humerus. These
are at risk of injury in shoulder dislocations and humeral neck fractures
(see Fig. 34.3).

The osteology of the upper limb 63