Although none of the editors of InsideSurgery.com are involved in the care of CBS talk show host Matt Lauer, we have noted news reports of his fall off of a bicycle while attempting to avoid a deer. He suffered a separated shoulder that required surgery.
The technical name for a shoulder separation is an acromioclavicular (AC) dislocation. The shoulder joint is made by the head of the humerus fitting into the acromion with the overlying distal end of the clavice.
There are ligaments holding the humerus in place that run from the coracoid process of the humerus to the both the clavicle and the acromion (part of the scapula) Typically the clavicle is displaced superiorly (up) and posteriorly.
These injuries usually occur when there is a direct force applied to the lateral shoulder. Shoulder separations are common injuries after falls from bicycles.
Patients always complain of pain and are tender when the shoulder is palpated. Plain radiographs required include an anterior/posterior view of both AC joints on one plate for comparison sake, an axillary lateral view, and a 10 to 15 degree cephalic tilt view. Almost all experienced orthopedic surgeons also get an MRI or CT scan to evaluate the injury.
Anterior posterior radiograph showing overlap of glenoid and medial aspect of humeral head.
Shoulder separations are classified into six types.
Type 1 – the AC ligaments (from the humerus to the clavicle) are sprained but not torn, there is no joint space widening on X-ray
Type 2 – the AC ligaments are torn and the coraclavicular ligaments (from the humerus to the clavicle) are sprained but intact. There is joint space widening on X-ray.
Type 3 – the AC and coraclavicular ligaments are both torn, there is joint space widening, the deltoid and trapezius muscles are torn from the clavice and the clavicle is displaced upwards.
Type 4 – type 3 injuries with the clavicle also displaced posteriorly
Type 5 – type 3 injuries with the rupture of the deltoid and trapezius muscles, the clavicle is severely displaced
Type 6 – the AC ligaments are torn, the coracoligaments are intact, the distal clavicle lies inferior to the acromion process. These are rare injuries occuring with the shoulder is abducted and externally rotated. This type of injury might occur if a patient was falling off a ledge and was grabbed by the hand or wrist and yanked upwards to safety.
Type 1 and 2 shoulder separations are treated nonoperatively with a sling, ice, and pain medications. Type 3 injuries can be treated either conservatively or with surgery. Type 4, 5, and 6 injuries are treated operatively, many through arthroscopic minimally invasive approaches.