History:  49-year-old man falls from a step ladder and injures his L shoulder.  He did not strike his head.  The patient is unable to move his shoulder without considerable pain and now has a “bump” in the area of his L shoulder that wasn’t previously there.  Medical history is unremarkable except for a prior Anterior Cervical Discectomy and Fusion many years ago.

Physical Examination:  Vitals are normal, and the patient is not in mild to moderate distress.  Neurologic exam is normal.  Exam of the L shoulder shows some mild swelling, a palpable deformity at the AC joint area.  On testing, the patient has considerable pain in trying to reach his hand on the side of the affected shoulder across his body to touch his other shoulder. 

Radiography demonstrates abnormal elevation of the clavicle most significant at the AC joint and prior ACDF.

Diagnosis:  Acromioclavicular dislocation

Pathology:  Complete disruption of the Acromioclavicular ligament/capsule and the Coracoclavicular ligament. 

Classification of AC separations by the Rockwood criteria:

Type 1 AC joint capsule is stretched and partially disrupted

Type 2 AC joint capsule and Coracoclavicular ligaments are stretched and partially disrupted

Type 3 AC joint capsule and Coracoclavicular ligaments are both completely disrupted, and clavicle is elevated superiorly

Type 4 AC joint capsule and Coracoclavicular ligaments are both completely disrupted plus avulsion of the Coracoclavicular ligament from the clavicle and clavicle is displaced posteriorly

Type 5 Clavicle markedly elevated and Coracoclavicular distance more than double normal.  Deltoid and Trapezius detached

Type 6 Inferolateral dislocation of lateral end of the clavicle

(Types 4,5, and 6, are variants of type 3. 

Courtesy Radiopaedia.org

 Treatment:

Type’s 1 and 2 AC joint separations require NSAIDS, sling, rest followed by physical therapy, if needed.  They are non-surgical.

Type 3 AC separations can be treated either medically or surgically, depending on occupation (secretary vs manual laborer), or sport (soccer player vs football or ice hockey player).  Many will do fine medically but need to individualize treatment based on circumstances.

Type’s 4-6 all require surgery. 

Of note:  The above x ray is only an AP view and would need an axillary lateral view to help determine whether the separation is type 3 or 4.  

Hook plate and claw s/p surgical correction of AC joint separation

All X-rays courtesy of Open Access Radiopaedia.org and Hugh M. Dainer MD