Chapter 73 - The Unstable Shoulder

Question 1

position of arm for an anterior dislocation

Answer 1

abduction, external rotation

Question 2

position of arm for a posterior dislocation

Answer 2

posterior force on a forward flexed, adducted arm

Question 3

what is the primary passive restraint to glenohumeral motion?

Answer 3

labrum

Question 4

what is the primary passive restraint to anterior dislocation in a position of vulnerability?

Answer 4

anterior band of the IGHL

Question 5

what is the primary passive restraint to posterior dislocation in the position of vulnerability

Answer 5

posterior band of the IGHL

Question 6

number one predictor of redislocation after first time anterior dislocation?

Answer 6

Age
activity level, males, contact sports

female gender is protective

Question 7

bankhart lesion

Answer 7

detachment of the anteroinferior labrum and the anterior band of the IGHL from the glenoid surface

Question 8

ALPSA lesion

Answer 8

periosteal sleeve injury causing the anteroinferior labrum to ball up medial to the glenoid

Question 9

What is the most common brachial plexus injury following shoulder dislocation

Answer 9

axillary nerve injury in 13% of dislocations
mixed plexus is 2nd most common

Question 10

hill-sachs lesion

Answer 10

compression fracture on the posterosuperior humeral head caused by impaction on the anteriorinferior glenoid rim

Question 11

who should get immediate surgical stabilization following first time dislocation

Answer 11

• patient <25 with high demand/contact athletic participation
• concomitant RC Tear
• large bone loss

Question 12

for an in season athlete - how long until they can return to play with a first time dislocation treated non-op

Answer 12

~2 weeks

Question 13

Arthroscopic vs open bankhart

Answer 13

• large bony piece (arthroscopic bankhart is not the right answer)

Question 14

primary complication following open bankhart

Answer 14

subscap failure

Question 15

presentation of an acute posterior dislocation

Answer 15

• arm locked in internal rotation
• prominent posterior shoulder
• prominent coracoid
• limited ability to externally rotate the shoulder

Question 16

surgical options to treat an engaging hill-sach’s lesion

Answer 16

• lesser tuberosity or subscap transfer into the defect (Mclaughlin/modified mcglaughlin)
• structural allograft to the humeral head

Question 17

most common complication following operative posterior instability tx

Answer 17

re-dislocation
- recurrence rate is highest in overhead athletes

overtightening of the posterior capsule can lead to anterior subluxation

Question 18

pathophysiology of multidirectional instability

Answer 18

1. patulous inferior capsule (contains both the anterior and posterior bands of the IGHL)
2. functional deficiency of the rotator interval