Exam 2 Lecture 2 Talar Neck Fractures Dr. Dayton

Question 1

What three joints is the talus a part of?

Answer 1

STJ
TN
Ankle

Question 2

What are the four arteries that feed the talus?

Answer 2

Artery of the tarsal canal from both the perforating peroneal artery and the lateral tarsal artery of the dorsalis pedis

Artery of the tarsal sinus from both the anterior tib and perforating tib.

The dorsal neck vessels from the anterior tibial artery.

The deltoid branches from the posterior tibial artery.

Question 3

Which artery supplies most of the talar body?

Answer 3

The artery of the tarsal canal from the perforating peroneal and the posterior tibial arteries.

Question 4

What is the general mechanism of injury to the talar talus?

Answer 4

Hyper dorsiflexion of the foot on the tibia.

Neck of the talus impinges against the anterior distal tibial leading to a neck fracture!

Question 5

Describe a Hawkins 1 deformity.

What is the risk of AVN?

Answer 5

Non displaced talar neck fracture.

0-13% AVN chance

Question 6

Describe a Hawkins 2 deformity.

What risk of AVN does Hawkins 2 have?

Answer 6

Displaced talar neck fracture with subtalar subluxation.

AVN 20-50%

Question 7

Describe a Hawkins 3 deformity.

what risk of AVN does hawkins 3 have?

Answer 7

Subtalar and Ankle joint dislocated with talar neck fracture.
The talar body is normally tethered around the detoid ligament.

AVN 83-100%

Question 8

What are the two radiographic hallmarks of AVN?

Answer 8

Ischemia resulting from arterial interruption.

Leads to sclerosis and collapse seen radiograpically.

Question 9

Which imaging modality is extremely sensitive to avascular necrosis?

Answer 9

MRI’s.

Plain radiographs will however show sclerosis as seen in AVN.

Question 10

How do you treat AVN precollapse?

Answer 10

Modified WB with PTB cast.

Question 11

How do you treat AVN post collapse?

Answer 11

Observation and Blair fusion if symptomatic.

Question 12

What is the Hawkins Classification used for?

Answer 12

Classification of Talar neck fractures.

Question 13

When do you see osteochondral defects of the talar dome?

Answer 13

typically with recurrent sprains and instability.

Question 14

What does the Berndt and Hardy Classification describe?

Answer 14

Osteochondral defects of the talar dome.

Question 15

Describe a Class 1 Berndt and Hardy Classification

Answer 15

Small area of compression within the talar dome (OCD)

Question 16

Describe a Class 2 Berndt and Hardy Classification

Answer 16

Partially detached Osteo Chondral defect of the talar dome

Question 17

Describe a Class 3 Berndt and Hardy Classification

Answer 17

Fully detached OCD that remains in a crater

Question 18

Describe a Class 4 Berndt and Hardy Classification

Answer 18

Fully displaced osteochondral defect.

Question 19

Medial osteochondrial defects are commonly found….

Answer 19

Posteriorly and are most commonly deeper.

Question 20

Lateral osteochondral defects of the talar dome are commonly found….

Answer 20

Commonly found more anteriorly and are generally shallower.

Question 21

Which two classification levels of the Berndt and Hardy Classification have the possibility to heal on there own?

Answer 21

1 and 2

1 is a shallow area of compression.

2 is a partially detached OCD