Scapula

Scapula

Type - 

Flat

Quantity -

2 in numbers

Location 

• It is posterolateral aspect of the thorax, against 2-7th rib.

Side Determination

• Glenoid cavity looks laterally.
• Coracoid process is directed forwards anteriorly.
• Spinous process always posteriorly.

Features

Surfaces 

1. Costal Surface

2. Dorsal Surface

Costal Surface

• It is also called as subscapular fossa.
• It is concave.

Costal surface of right scapula

Dorsal Surface

A spine divide it (Dorsal Surface) into two parts...

1. Supra Spinous fossa or Surface.

2. Infra Spinous fossa or Surface.

Dorsal surface of right scapula

Borders

1. Superior Border.

2. Lateral Border.

3. Medial Border

Superior Border

• It is thin and shortest  border.
• Suprascapular notch present on it.

Lateral Border

It is the thickest border.

Medial Border

It is also called as vertebral border.

Angles

1. Superior Angle.

2. Inferior Angle.

3. Lateral Angle.

Superior Angle

It covered by trapizeus muscle.

Inferior Angle

It covered by latissimus dorsi.

Lateral Angle

• It bears glenoid cavity.
• It is also called as glenoid angle.
• It is also called as head of scapula.

Process

1. Spinus Process.

2. Acromial Process.

3. Coracoid Process.

Spinus Process

• It is also called as spine of scapula, which is divides dorsal surface into supra spinus fossa and infra spinus fossa.
• It has two surfaces (Superior and Inferior).

Acromial Process

• It projects forwards from lateral end of spine.
• It over hence the glenoid cavity.

Coracoid Process

• It is directed forwards and slightly lateraly.
• It arise from upper part of glenoid cavity.
• Pectoralis major insert on it.

Attachment

1. Subscapularis arise from the medial two-third of the subscapular fossa.

2. Supraspinatus arises from the medial two-third of the supraspinous fossa.

3. Infraspinatus arise from the medial two-third of the infraspinous fossa.

Costal aspect muscle attachment

4. Deltoid arise from the lower border of the crest of the spine.

5. Trapezius is inserted into the upper border of the crest of the spine.

6. Serratus anterior is inserted along the medial border of the costal surface.

7. Long head of the biceps brachii arises from the supraglenoid tubercle, and short head from the lateral part of the tip of the coracoid process.

8. Coracobrachialis arises from the medial part of the tip of the coracoid process.

9. Pectoralis minor insert on coracoid process.

Dorsal aspect muscle attachment

10. Long head of the triceps brachii arises from the infraglenoid tubercle.

11. Teres minor arises by two slips on the dorsal surface along the lateral border. Circumflex scapular artery lies between the two slips.

12. Teres major arises from the dorsal aspect of the lateral border.

13. Levator scapulae is inserted along the dorsal aspect of the medial border.

14. Rhomboid minor and rhomboid major inserted into the medial border.

Superior aspect of the right scapula

15. Interior belly of the omohyoid arises from the upper border near the scapular notch.

16. Glenoidal labrum attached to the margin of the glenoid cavity.

17. Capsule of the acromioclavicular joint attached margin of the facet on the medial aspect of the acromion.

18. Coracoacromial ligament is attached to the coracoid process and acromion process.

19. Coracohumeral ligament is attached to the root of the coracoid process.

20. Coracoclavicular ligament is attached to the coracoid process.

Ossification

• One primary center appear during 8th week of intrauterine life.
• Seven secondary center appear for scapula.
• All center fused up to age of 20 years.
• Scapula's fusion are membranous. 

Ossification of scapula

Applied

• Paralysis of the serratus anterior causes 'winging' of the scapular.