Case 25: Shoulder Injury
Tuesday, August 23rd, 2011Author: Dr Danielle Coleman
This shoulder x-ray is from a 34yr old female knocked off her bicycle at low speed onto her right shoulder. The contour of her shoulder looks odd, and she cannot abduct the arm.
There is a widely used classification of these injuries (relating to the mechanism).
1. What is this classification?
Click to see the answerThe xray shows a fracture of the distal end of the right clavicle.
These fractures are divided into types A, B and C.
This shows a fracture of the distal clavicle, therefore this is a type B.
Type A involves the middle 1/3 of the clavicle and is by far the commonest type that occurs and represents 80% of clavicular fractures. These tend to result from a fall directly onto the shoulder.
Type B fractures affect the lateral 1/3 of the clavicle and account for 15% of these fractures. These tend to occur when there is a direct blow to the tip of the shoulder.
Type C fractures occur the least frequently, about 5%, and involve the medial 1/3 of the clavicle. These mainly occur with blows to the anterior chest wall.
2. Displacement of this fracture can occur with disruption to which ligaments?
Click to see the answerCoraco-clavicular ligements. The proximal fragment of the clavicle is then pulled superiorly by the strong action of the sternocleidomastoid muscle. This may cause tenting of the skin overlying the clavicle and should be looked for on examination.
3. If the patient develops shortness of breath following an injury like this, what complication may have occurred?
Click to see the answerPneumothorax. The sharp end of the fracture may cause an injury to the underlying lung causing a pneumothorax and therefore these symptoms. Other complications can include neurological injury to the brachial plexus or vascular injury to the subclavian artery, and these should be examined for.