Acromioclavicular Joint Injuries

Question 1

What makes the AC joint vulnerable to injury from direct trauma?

Answer 1

Its location

Question 2

What are AC joint injuries sometimes referred to as?

Answer 2

Shoulder sprains or separations

Question 3

The AC ligaments primarily resist what types of forces?

Answer 3

anterior and posterior

Question 4

The coracoclavicular ligaments primarily resist what types of forces?

Answer 4

superior and axial

Question 5

The AC joint is involved in -% of shoulder girdle injuries

Answer 5

9-12

Question 6

How do AC joint injuries tend to occur?

Answer 6

A direct blow or falling onto a adducted shoulder

Question 7

How many types of AC joint injury classifications are there?

Answer 7

6 (I-VI)

Question 8

Describe a type I AC joint injury

Answer 8

The AC joint is still intact and this type of injury is referred to as an AC ligament strain

Question 9

What will the x-ray findings be for a type I AC joint injury?

Answer 9

Normal

Question 10

Describe a type II AC joint injury

Answer 10

The AC ligament is torn, but the coracoclavicualr ligament is intact which results in subluxation of the AC joint.

Question 11

What will the x-ray findings be for a type II AC joint injury?

Answer 11

Slight widening of the AC joint, the clavicle will be elevated 25-50% above the acromion, and the coracoclavicular interspace will be slightly widened

Question 12

Describe a type III AC joint injury

Answer 12

Both the AC and CC ligaments are torn which results in complete dislocation of the AC joint

Question 13

What will the x-ray findings be for a type III AC joint injury?

Answer 13

AC joint dislocated 100% and the coracoclavicular interspace widened 25-100%

Question 14

Describe a type IV AC joint injury

Answer 14

There is complete dislocation with posterior displacement of the distal clavicle into or through the trapezius muscle

Question 15

What will the x-ray findings be for a type IV AC joint injury?

Answer 15

May appear similar to type II and II, however the axillary radiograph will demonstrate posterior dislocation

Question 16

Describe a type V AC joint injury

Answer 16

There is superior dislocation of the joint 1-3 times the size of the normal spacing, which increases the CC ligament distance 2-3 times normal and causes disruption of the deltotrapezial fascia

Question 17

What will the x-ray findings be for a type V AC joint injury?

Answer 17

AC joint dislocated and generally 200-300% disparity of the coracoclavicular interspace compared to the normal shoulder

Question 18

Describe a type VI AC joint injury

Answer 18

There is complete dislocation of the AC joint with inferior displacement of the distal clavicle into a subacromial or subcoracoid position

Question 19

What will the x-ray findings be for a type VI AC joint injury?

Answer 19

AC joint dislocation and the clavicle displaced inferiorly

Question 20

What x-ray view is most useful to diagnose AC joint injuries?

Answer 20

Zanca view

Question 21

How are type I and II injuries treated?

Answer 21

Rest, ice, analgesics, and immobilization, followed by early range of motion exercises

Question 22

How are type III injuries treated?

Answer 22

Treatment is controversial, the trend over the last several decades for the initial treatment of type III injuries has moved from operative to nonoperative in the majority of cases

Question 23

How are type IV, V, and VI injuries treated?

Answer 23

surgery