Osteology of scapula, clavicle + humerus

Question 1

What is the joint between the scapula + humerus?

Answer 1

Glenohumeral joint

Question 2

What is the joint between the scapula + clavicle?

Answer 2

Acromioclavicular joint

Question 3

What is the concave depression on the costal/anterior surface of the scapula?

Answer 3

Subscapular fossa

Question 4

What is the hook-like projection under the clavicle?

Answer 4

Coracoid process (pec. minor inserts, coracobrachialis + short head of biceps brachii originate)

Question 5

What is the glenoid fossa?

Answer 5

Shallow cavity on scapula, articulates with glenohumeral joint

Question 6

What are the supraglenoid tubercle + infraglenoid tubercle?

Answer 6

Roughening superior/inferior to glenoid fossa, origin of long head biceps brachii or long head triceps brachii

Question 7

What is the acromion of the scapula?

Answer 7

Projection @ lateral end of scapula = acromioclavicular joint

Question 8

What are the supraspinous/infraspinous fossa?

Answer 8

Above/below spine of scapula, origin of supraspinatus/infraspinatus

Question 9

What is the scapulothoracic ‘joint’?

Answer 9

Anterior scapula + rib cage = not a true joint

Question 10

Cause of scapula fracture + why they don’t need fixation

Answer 10

Severe chest trauma = crushing/RTA/high-impact sports injuries
Tone of surrounding muscles holds fragments in place whilst healing occurs

Question 11

Where does the clavicle extend between?

Answer 11

Manubrium of sternum + acromion

Question 12

3 functions of clavicle

Answer 12

Attach upper limb to trunk
Transmit force from upper limb to axial skeleton
Protect neurovascular structures of upper limb

Question 13

What is the shape of the clavicle?

Answer 13

Medial (sternal end) = convex anteriorly

Lateral (acromial end) = concave

Question 14

What forms the coracoclavicular ligament?

Answer 14

Conoid ligament (medial) on conoid tubercle
Trapezoid ligament (lateral) on trapezoid line

Question 15

What are the 2 atypical features of the acromioclavicular (AC) joint?

Answer 15

Articular surfaces lined with fibrocartilage

Joint cavity partially divided by articular disc

Question 16

What 3 ligaments strengthen the AC joint?

Answer 16

AC ligament = horizontal from acromion to lateral clavicle, reinforces superior aspect

Conoid + trapezoid = extrinsic, both from coracoid process

Question 17

What movements are at the AC joint?

Answer 17

Passive as no muscles
Axial rotation
Anteroposterior movement

Question 18

Where is the sternoclavicular joint?

Answer 18

Clavicle + manubrium of sternum, upper 1st costal cartilage

Question 19

Why is the sternoclavicular joint in 2 compartments by a fibrocartilaginous articular disc?

Answer 19

Allow clavicle + manubrium to slide freely over each other

Rotation in 3rd axis

Question 20

What movements of the shoulder also require movement @ the sternoclavicular joint?

Answer 20

Elevation/depression of shoulder joint
Protraction/retraction
Rotation

Question 21

Where do 3 of the rotator cuff muscles insert?

Answer 21

Greater tubercle

Question 22

What inserts onto the lesser tubercle?

Answer 22

Subscapularis

Question 23

How to remember the insertion of muscles @ intertubercular sulcus

Answer 23

“Lady between 2 majors”

Latissimus dorsi between pec. major (lateral lip) + teres major (medial lip)

Question 24

What is in close proximity to the surgical neck of the humerus?

Answer 24

Axillary nerve

Circumflex humeral vessels

Question 25

What lies in the radial groove on posterior humerus?

Answer 25

Radial nerve

Profunda brachii artery