BONES OF UPPER LIMB
Conoid and trapezoid parts
of coracoclavicular ligament
Suprascapular notch and ligament
Omohyoid (inferior belly)
short head of biceps brachii
Biceps brachii, long head
Capsule of acromioclavicular
Fig.2.10: Right scapula: Superior aspect
16 The inferior belly of the omohy oid arises from the upper
border near the suprascapular notch (Fig. 2.8).
17 The margin of the glenoid cavity gives attachment
to the capsule of the shoulder joint and to the
glenoidal labrum (Latin lip) (Fig.2.8).
f8fle margin of the facet on the medial aspect of the
-acromion gives attachment to the cnpsule of the
scromioclnoicular joint (Fig. 2.10).
19 The coracoacromial ligament is attached (a) to the
lateral border of the coracoid process, and (b) to the
medial side of the tip of the acromion process (Figs
2.10 and 6.7).
20 The coracohumeral ligament is attached to the root of
the coracoid process (Fig. 2.10).
21 The coracoclavicular ligament is attached to the
coracoid process: The trapezoid part on the superior
aspect, and the conoid part near the root (Fig. 2.10).
22 The transaerse ligament bridges across the
suprascapular notch and converts it into a foramen
which transmits the suprascapular nerve. The
suprascapular vessels lie above the ligament (Fig. 2.10).
23 The spinoglenoid ligament may bridge the
spinoglenoid notch. The suprascapular vessels and
nerve pass deep to it (Fig. 10.3).
The scapula ossifies from one primary centre and
seven secondary centres. The primary centre appears
near the glenoid cavity during the eighth week of
development. The first secondary centre appears in
the middle of the coracoid process during the first
year and fuses by the 15th year. The subcoracoid
centre appears in the root of the coracoid process
during the 10th year and fuses by the 16th to l8th
years (Fig. 2.11). The other centres, including two for
the acromion, one for the lower two-thirds of the
margin of the glenoid cavity, one for the medial
border and one for the inferior angle, appear at
puberty and fuse by the 25thyear.
The fact of practical importance is concerned with
the acromion. If the two centres appearing for
acromion fail to unite, it may be interpreted as a
fracture on radiological examination. In such cases,
a radiograph of the opposite acromion will mostly
reveal similar failure of union.
r Paralysis of the serrafus anterior causes 'winging'
of the scapula. The medial border of the bone
becomes unduly prominent, and the arm cannot
be abducted beyond 90 degrees (Fi9,2.12).
. The scaphoid scapula is a developmental anomaly,
in which the medial border is concave.
The humerus is the bone of the arm. It is the longest
bone of the upper limb. It has an upper end, a lower
end and a shaft (Figs 2.13 and2.1.4).
1 The upper end is rounded to form the head. The
lower end is expanded from side to side and flattened
from before backwards.
2 The head is directed medially, upwards and
3 The lesser tubercle projects from the front of the
upper end and is limited laterally by the
intertubercular sulcus or bicipital groove.