clavicle & scapul OSTEOLOGY BY TERANCE

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