1 Skeletal Anatomy 19

FIGURE 1.10. A: Illustration of humerus showing centers of

ossification. There are eight ossification centers: one each

for the shaft, the head, the greater tuberosity, the lesser

tuberosity, the capitulum, and the trochlea, and one for

each epicondyle. B: Schematic illustration of proximal and

distal humerus in a young adult showing epiphyseal lines.

The dark lines indicate the attachment of the articular capsule.

A B

tuberosities. The circumference of the anatomic neck provides attachment for the articular capsule of the shoulder

joint. In this area, there are numerous foramina for nutrient

vessels (4).

The surgical neck is located distal to the anatomic neck

(see Figs. 1.11 and 1.12). It is the area of the junction of the

shaft with the proximal end of the humerus, just distal to

the head and tuberosities. As opposed to the anatomic neck,

there is no groove that delineates the surgical neck. Its name

derives from the common occurrence of fractures in this

area, many of which are managed by operative methods.

The greater tuberosity is located lateral to the head and

lateral to the lesser tuberosity (see Figs. 1.11 to 1.13). The

greater tuberosity often is referred to as the greater tubercle

in anatomy textbooks (4,5). The upper surface is rounded

and contains three flat impressions for muscle insertion.

The superiormost portion of the greater tuberosity provides

insertion for the supraspinatus. The middle impression is

for the infraspinatus, and the inferiormost impression for

the teres minor. The insertion site for the teres minor lies

approximately 2.5 cm distal to the insertion of the

supraspinatus, and a portion of the teres minor inserts onto

the shaft.