Shoulder

Question 1

Name all AC joint ligaments

Answer 1

anterior, posterior, superior, inferior

Question 2

What direction do AC ligaments provide stability?

Answer 2

anterior posterior direction

Question 3

Name all coracoclavicular ligament portions

Answer 3

conoid(medially) and trapezoid(laterally)

Question 4

What direction do CC ligaments provide stability?

Answer 4

superior inferior direction
-conoid > trapezoid

Question 5

When does middle GH ligament most contribute to shoulder stability?

Answer 5

shoulder abducted 45* and externally rotated

Question 6

Name both bands and relative positions of inferior GH ligament

Answer 6

anterior band (2 to 4 o clock)
-resists anterior translation when shoulder abducted 90 degrees and externally rotated

posterior band (7 to 9 o clock)
-resists posterior translation when shoulder flexed and internally rotated

Question 7

What does inferior GH ligament mainly stabilize?

Answer 7

primarily inferior GH joint translation

Question 8

Force couples at GH joint

Answer 8

subscapularis and infraspinatus provide dynamic stability
-compressive force in transverse plane
-infraspinatus prevents superior and anterior translation
-subscapularis involved w/ forward flexion

all rotator cuff muscles and deltoid muscles
-compression to offset force of deltoid and pec muscles

Question 9

Greatest predictors for failed surgical repair of rotator cuff tear

Answer 9

Fat infiltration OR=9.3
Multiple tendon involvement OR=6.0
Larger tear size OR=4.3
Lower pre-op muscle strength OR=4.0
Older age OR=2.8