The clavicle and scapula are summarized as follows: 1. The clavicle has a shaft with medial and lateral ends that articulate with the sternum and acromion respectively. It is the first bone to ossify and provides attachments for muscles like the deltoid and pectoralis major. 2. The scapula is a flat, triangular bone with three angles, three processes, and two surfaces. It has attachments for rotator cuff and back muscles. The glenoid fossa articulates with the humerus to form the shoulder joint. 3. Both bones ossify from primary and secondary centers, with the clavicle being the first bone to start

1. OSTEOLOGY OF CLAVICLE &
SCPULA

2. The Clavicle

3. Parts
• Shaft
• Medial end
• Lateral end

4. SHAFT
•Lateral 1/3rd -Two borders; anterior & posterior
• Anterior border, concave forwards
• Posterior border, convex backwards
-Two surfaces; superior & inferior
• Superior surface is subcutaneous
• Inferior surface has,
• Elevation called conoid tubercle for the attachment of conoid ligament
• Ridge called trapezoid ridge for the attachment of trapezoid ligament

5. • Middle 1/3rd -Rounded
-Four surfaces
• Anterior surface, convex forwards
• Posterior surface, smooth
• Superior surface, rough in its medial par
• Inferior surface has rough oval impression, at the medial end
longitudinal subclavian groove, at the lateral half
nutrient foramen, at the lateral end of the groove
• Medial 1/3rd –is round and give raise to the articular surface

6. • Lateral end (acromial end)
-Flattened from above-downwards
-Bears a facet that articulates with the acromion process of the scapula to form
the acromioclavicular joint
• Medial end (sternal end)
-quadrangular
-articulates with clavicular notch of manubrium sterni

7. • Side determination
• Ends: lateral, flattened & medial, quadrilateral
• Curves: convex forwards, medial 2/3 & concave forwards, lateral 1/3
• Trapezoid ridge: inferior surface is grooved longitudinally, in medial 1/3
• Sex determination
• In females, clavicle is;
• Shorter
• Lighter
• Thinner
• Smoother
• Less curved, than in males

8. Peculiarities of the Clavicle
• Only long bone that lies horizontally
• First bone to start ossifying
• Subcutaneous throughout
• Generally, no medullary cavity

9. Attachments on the Clavicle
• Lateral end
-joint capsule at the margin of the articular surface for the
acromioclavicular joint
• Medial end
-joint capsule at the margin of the articular surface for the
sternoclavicular joint
-Interclavicular ligament (superiorly)

10. • Lateral one third of shaft
• Origin of deltoid muscle (anterior border)
• Insertion of trapezius muscle (posterior border)
• Conoid & trapezoid parts of the coracoclavicular ligament (at conoid tubercle &
trapezoid ridge) gets attached
• Medial two thirds of shaft
• Origin of pectoralis major muscle (anterior surface)
• Origin of clavicular head of the sternocleidomastoid muscle (rough superior surface)
• Costoclavicular ligament (oval impression on the inferior surface)
• Insertion of subclavius muscle (subclavian groove)
• Clavipectoral fascia (margins of the subclavian groove)

11. Ossification
• First bone in the body to ossify
• Ossifies in membrane, except for its medial end
• Two primary centres
• Appear in shaft
• During 5-6 weeks of intrauterine life
• Fuse with each other about the 45th day
• One secondary centre
• Appears in medial end
• During 15-17 years after birth
• Fuses with shaft during 21-22 years
• Occasionally there may be a secondary ossification centre for the acromial
end also

12. The Scapula

13. • Anatomy of Scapula
Flat bone, triangular bone
Placed on the posterolateral aspect of the thoracic cage
Has 2 surfaces, 3 borders, 3 angles & 3 processes

14. Surfaces
• Two surfaces
Costal surface (subscapular fossa)
• Concave forwards
• Directed anteromedially
• Marked by three longitudinal ridges
Dorsal surface
• spine of the scapula is attached
• spine divides the surface into;
• smaller supraspinous fossa
• larger infraspinous fossa
• the two fossae are connected by the spinoglenoid notch (situated
lateral to the root of the spine)

15. Borders
• Three borders
Superior border
• Thin
• Shorter
• Supraclavicular notch is presents (near the root of the coracoid process)
Lateral border
• Thick
• Acts as a lever for the action of the serratus anterior muscle in overhead abduction of the arm
• Infraglenoid tubercle presents (at the upper end)
• There is a rough stripe on the dorsal surface along the border (origin of teres major & teres
minor muscles)
Medial border
• Thin
• Extends from superior angle to inferior angle

16. Angles
• Three angles
• Superior angle
• Formed by superior border and medial border
• Covered by trapezius muscle
• Inferior angle
• Formed by lateral and medial border
• Covered by latissimus dorsi muscle
• Moves forward round the chest, when the arm is abducted
• Lateral angle (Glenoid angle)
• Broad
• Bears the glenoid fossa (glenoid cavity), which is directed forwards, laterally & slightly
upwards
• Supraglenoid tubercle is presents (superior to the glenoid fossa)
• Infraglenoid tubercle is presents (inferior to the glenoid fossa)

17. Processes
• Three processes
• Spine (spinous process)
• Triangular plate of bone
• Has three borders (anterior[root], posterior[crest] & lateral)
• Crest (posterior border) has a upper lip & a lower lip
• Has two surfaces, which divides the scapular dorsal surface into supraspinous &
infraspinous fossae
• Acromion
• Two borders; medial & lateral
• Two surfaces; superior & inferior
• Forms the facet for the clavicle
• Coracoid process
• Directed forwards & slightly laterally

18. Attachments on the Scapula
• Muscles
Origin of multipennate subscapularis muscle from the medial two-thirds of the subscapular
fossa (costal surface)
Origin of supraspinatus muscle from;
• medial two-thirds of the supraspinous fossa
• superior surface of the spine
Origin of infraspinatus muscle from;
• medial two-thirds of the infraspinous fossa
• inferior surface of the spine
Origin of deltoid muscle from;
• lower lip of the crest
• lateral border of the acromion (acromial fibers are multipennate)
Insertion of trapezius muscle into;
• upper lip of crest
• medial border of the acromion

19. Insertion of serratus anterior ;
Along the medial border of the costal surface
• First digitations, from superior angle to root of spine
• Next two digitations to the medial border
Into the inferior angle
• Last five digitations to the inferior angle
Origin of long head & short head of the biceps brachii ;
long head arises from supraglenoid tubercle
short head arises from the lateral part of the tip of the coracoid process
Origin of coracobrachialis muscle from the medial part of the tip of the coracoid process
Insertion of pectoralis minor muscle into;
Medial border of the coracoid process
Superior surface of the coracoid process
Origin of long head of the triceps from the Infraglenoid tubercle

20. • Origin of teres minor muscle from the upper two-thirds of the rough strip on the dorsal surface
along the lateral border
• Origin of teres major muscle from the lower one-thirds of the rough strip on the dorsal aspect
of the lateral border
• Insertion of levator scapulae muscle along the dorsal aspect of the medial border, from the
superior angle to the root of the spine
• Insertion of rhomboideus minor muscle into the medial border (dorsal aspect) medial to the
root of the spine
• Insertion of rhomboideus major muscle into the medial border (dorsal aspect) between the
root of spine & inferior angle
• Origin of inferior belly of the omohyoid muscle from the medial border of the suprascapular
notch

21. Ligaments
Margins of the facet on the medial aspect of the acromion give attachment to the capsule of
the acromioclavicular joint
The coracoacromial ligament is attached;
• To the lateral borders of the coracoid process
• To the medial side of the tip of the acromion process
The coracohumeral ligament is attached to the root of the coracoid process

22. ossification
• Ossifies by 1 primary and 7 secondary centers
• Primary center appears near the glenoid during 8th week
• First secondary appears in the coracoid process during the 1st year
and fuses by 15 year
• Subcoracoid centers appears in the root of the coracoid process
during the 10th year and fuses by 16 to 18 years
• Other secondary centers including two from acromion appears by
puberty and fuse by 25 years