MSK Shoulder

Question 1

Rotator cuff tendons

Answer 1

Counterclockwise from posteroinferior:

1. Teres minor
2. Infraspinatous
3. Supraspinatous
4. Subscapularis

Question 2

Infraspinatus tendon course & insertion

Answer 2

runs superolaterally and inserts on greater tuberosity of humerus

Question 3

Supraspinatus tendon course & insertion

Answer 3

• mm runs horizontally w musculotendinous junction just lateral to AC joint
• tendon continues btw acromion & humeral head, and inserts on greater tuberosity of humerus w broad footprint

Question 4

Deltoid course & proximal insertion

Answer 4

inserts on acromion, extends laterally over humerus most superficial(?)

Question 5

Long head of biceps tendon course & insertion

Answer 5

-attaches to superior labrum and runs deep to supraspinatus

Question 6

Subscapularis tendon course and insertion

Answer 6

runs anterior to shoulder deep to coracoid process, attaches to lesser tuberosity of humerus and blends with transverse humeral ligament to cover bicipital grove (secures biceps tendon)

Question 7

Rotator interval

Answer 7

distance btw supraspinatus and subscapularis tendons

Question 8

Subdeltoid bursa location

aka subacromial

Answer 8

btw acromion & supraspinatus/infraspinatus

Question 9

Coracoacromial arch

Answer 9

Space btw coracoid, coracoacromial ligament, acromion, and humeral head

Question 10

Causes of shoulder impingement syndrome

Answer 10

Any condition that limits space within coracoacromial arch:

1. Abnormal acromion shape
   
   • type III, inf hook
2. Abnormal acromion orientation
   
   • ant downslope (sag)
   • inferolat tilt (cor)
   • low-lying
3. AC degen
4. Os acromiale
5. Thick CoAc ligament
6. p-traumatic osseous deformity
7. instability
8. Muscle hypertrophy

Question 11

Sequelae of shoulder impingement syndrome

Answer 11

• supraspinatus tendon degen/tear
• long head biceps tendon degen/tear
• degen cysts/sclerosis of greater tuberosity
• subdeltoid/subacromial bursitis

Question 12

Posterosuperior impingement syndrome & MR findings

Answer 12

• impingement of supraspinatus and infraspinatus btw humeral head and posterosuperior labrum
• occurs w maximal ABER

MRI findings:

• humeral cysts adj to infra insertion
• supra & infra undersurface tears
• p-sup labral tear

Question 13

Required views for trauma series

Answer 13

.

Question 13

Glenohumeral ligaments & attachments (there are 3)

Answer 13

• SGHL & MGHL: supraglenoid tubercle to lesser tuberosity
• IGHL: 2 bands from inf glenoid labrum to neck of humerus (ant & post)
• “Z” configuration on coronal

Question 14

Biceps pulley components

Answer 14

Medial limb of CHL

SGHL

Question 15

Pulley injuries & subtypes

Answer 15

Def: interrupted sheath around LHBT with intact rotator cuff

Type 1- isolated pulley tear (CHL-SGHL sling)
Type 2- Type 1 + articular-sided tearing of SUPRA + mild medial subluxation LHBT
Type 3- Type 1 + articular-sided tearing of SUBSCAP + mild medial subluxation LHBT
Type 4- Type 1 + articular-sided tearing of SUPRA & SUBSCAP + DISLOCATED LHBT