Pectoral Girdle Arthrology

Question 1

Joints of the pectoral girdle

Answer 1

Sternoclavicular joint
Acromioclavicular joint
Glenohumeral joint

Question 2

Sternoclavicular joint classification

Answer 2

Synovial
Saddle
Complex
Multi-axial

Question 3

Articulating surfaces of Sternoclavicular joint

Answer 3

CLAVICLE: larger than sternum artic surface.
Medial end concave vertically, convex AP. Concavity continued inferiorly to allow articulation with the first rib
MANUBRIUM: convex vertically, concave AP
INTRA-ARTIC FIBROCART DISC: improves congruency, facilitates increased ROM, shock absorbance

Provides bony point of contact between pectoral girdle and upper limb
Reciprocally concavoconvex
All covered in fibrocartilage not hyaline

Question 4

Sternoclavicular joint capsule

Answer 4

Surrounds joint like a sleeve
Attaches to articular margins of clavicle and sternum
Inferior aspect passes between clavicle and superior 1st costal cartilage
Strong capsule (except inferiorly)
Strengthened ant/post/sup by thickenings (ant/post/interclavicular ligs)

Question 5

Sternoclavicular synovial membrane/disc

Answer 5

Two separate membranes to account for 2 separate cavities
Lines the capsule from all articular surfaces

Disc separates the joint into 2 synovial cavities
Provides congruency, facilitates ROM and shock absorbance

Question 6

Ligaments of the Sternoclavicular Joint

Answer 6

Anterior Sternoclavicular ligament
Posterior Sternoclavicular ligament
Interclavicular ligament
Costoclavicular ligament

Question 7

Anterior and posterior Sternoclavicular ligaments

Answer 7

Broad band

ANTERIOR: upper anterior aspect of sternal/medial end of clavicle to anterior manubrium
POSTERIOR: upper posterior aspect of sternal/medial end of clavicle to posterior manubrium

Question 8

Interclavicular ligament

Answer 8

Flat band
Attaches from each upper sternal end of clavicles to upper manubrium
Limits superior clavicle movement by producing bilateral pressure

Question 9

Costoclavicular ligament

Answer 9

Short and strong
Attaches to inferior clavicle, to upper medial 1st rib/costal cartilage
Major stabiliser of the sternoclavicular joint
Limits clavicle elevation (and ant/post movements)
Anterior lamina fibres attach to costal cartilage
Posterior lamina fibres attach to 1st rib

Question 10

Movements of the Sternoclavicular joint

Answer 10

(All movements secondary to those of the scapula)
Elevation/depression: elevation limited by costoclavicular, depression limited by interclavicular lig and disc

Pro/retraction: limited by ant/post and costoclavicular ligs

Axial rotation: relatively small, produced by scapula, transmitted by costoclavicular lig