Chapter 89 - Fractures of the Clavicle, Scapula, and Glenoid

Question 1

Clavicle is the only long bone to form via what form of ossification

Answer 1

intramembranous ossification - no cartilaginous precursor

remodelling occurs via haversian canals

flat bones tend to form via intramembranous ossification

Question 2

primary blood supply to the clavicle

Answer 2

periosteal - there is no nutrient artery

Question 3

surgical indications for a lateral 1/3 clavicle fracture

Answer 3

• non op: type I (lateral to the CC ligaments), III (into the AC joint), IV (pediatric physeal injury mimicking a AC separation)
• opertive: Type IIA (medial to the CC ligaments), type IIB (involving only the conoid ligament) and type V (avulsion of the CC ligaments off the clavicle

Question 4

surgical indications for a middle 1/3 clavicle

Answer 4

open
vascular injury
poly trauma
>20mm shortening

Question 5

what operative fixation technique is better for cantilever bending?

Answer 5

anterior-inferior plating (cantilever bending is the physiologic force felt at the clavicle)

Question 6

what operative fixation technique is better for axial compression?

Answer 6

superior plating

Question 7

what additional injuries should you consider if a clavicle fracture is significantly distracted on XR?

Answer 7

scapulothroacic dissociation or brachial plexus injury

Question 8

displaced lateral third fracture outcomes

Answer 8

inherently unstable and prone to non-union

Question 9

risk factors fo clavicle non-union

Answer 9

smoking, advanced age, distal-fifth fractures, displaced transverse fractures, female sex, comminutionn/displacement

Question 10

what other injuries are seen in scapular fractures?

Answer 10

80% have pneumothroax or hemothorax
50% will have another ipsilateral extremity injury
head injury in 15%

Question 11

coracoid fracture classification

Answer 11

I: proxima to the CC ligaments - associated with other SSC injuries - inherently unstable

II: toward the tip of the coracoid

Question 12

classification of acromion fractures

Answer 12

I: non-displaced
II: displaced but does not impact sub acromial space
III displaced and impacting the sub acromial space

Question 13

surgical indications for coracoid or acromial fx

Answer 13

• painful non-union
• displacement >1cm
• multiple disruptions of the SSSC
• concomitant glenoid or scapular body fx that is already being operated on

Question 14

surgical indications for glenoid fracture fixation

Answer 14

• > 20% involvement
• displacement >4mm

Question 15

scapular body indications for surgery

Answer 15

glenopolar angle <20
lateral border medialization >20mm
angulation >45

Question 16

modified judet approach to the posterior scapula involves what interval?

Answer 16

infra (suprascapular n) and teres (axillary n)
deltoid gets reflected up

best for scapular neck fractures, posterior glenoid fractures