Scapula

The scapula (plural: scapulae) is a roughly triangular shaped bone of the pectoral girdle with several articulations connecting to the humerus and clavicle.

Gross anatomy

Osteology

The main part of the scapula, the body, consists of a somewhat triangular-shaped flat blade, with an inferiorly pointing apex, referred to as the inferior angle as well as lateral and superior angles. The scapula is described as having superior, medial, and lateral borders.

Posteriorly, the scapula is divided into a supraspinous fossa and infraspinous fossa by the scapular spine. Anteriorly, on the costal surface, is the shallow subscapular fossa.

Laterally is the glenoid fossa, anteriorly is the coracoid process and superiorly is the acromion that is continuous with the scapular spine and arcs anteriorly over the humeral head. The suprascapular notch lies immediately medial to the base of the coracoid process. The spinoglenoid notch lies posteriorly behind the neck.

Articulations
Attachments
Musculotendinous
Ligamentous

Blood supply

The scapula is surrounded by an arterial anastomosis, the scapular anastomosis which aims to ensure an adequate supply of blood to the upper limb, but has added benefit of adequate supply to the bone itself. It consists of the:

Variant anatomy

Development

See "ossification centers of the pectoral girdle" for information on the scapular ossification centers.

Related pathology

Fun fact

17 muscles attach to the scapula (in alphabetic order):

  • biceps brachii (both heads)
  • coracobrachialis
  • deltoid
  • infraspinatus
  • latissimus dorsi
  • levator scapulae
  • omohyoid inferior belly
  • pectoralis minor
  • rhomboid major
  • rhomboid minor
  • serratus anterior
  • subscapularis
  • supraspinatus
  • teres major
  • teres minor
  • trapezius
  • triceps brachii (long head)