Ortho Hors D'oeuvres (Answer):
To review, this is a 5 year-old boy with right shoulder pain after a fall from height with tenderness to palpation over the distal right clavicle.
Questions and answers:
1) What is the injury? What is the most common cause of this type of injury?
Pain at the distal end of the clavicle with radiographs that are negative for clavicular fracture is concerning for an AC separation, also known as a shoulder separation. This injury is often caused by direct blunt force direct to the superior or lateral aspect of the shoulder with the arm adducted, such as a direct blow or falling directly onto the shoulder. They are common injuries in motorcycle and bicycling accidents. In the above radiograph, you can see the clavicle is significantly displaced from the acromion (blue arrows), which clinches the diagnosis.
2) What other testing or imaging is needed?
As you can see in the above image, the clavicle is stabilized by multiple ligaments. The pertinent ligaments in shoulder separation are the AC ligament (between the acromion and the clavicle) and the CC ligament (between the coronoid and the clavicle).
There are 5 types of shoulder separations. Type I separations are characterized by AC tenderness with normal radiographs (including AC and CC distances). Type II separations are characterized by rupture of the AC joint with clavicular elevation to 25-50% above the acromion with minimal CC joint involvement. Patients with type III-VI separations have complete rupture of all supporting structures with varying degrees and types of deformity. Type IV is characterized posterior displacement of the clavicle, type V requires 200-300% increase in the coracoclavicular interspace, and type VI requires inferior clavicular displacement.
In patients with radiographically visible AC separations, an axillary x-ray is required to identify posterior clavicular displacement (and therefore a type IV shoulder separation). Other more advanced types of clavicle displacement (inferior and severe CC disruption) should be visible on normal AP/lateral x-rays of the shoulder.
3) What is the appropriate initial management of this patient’s injury?
Initial management is the same for all types of shoulder separation. The patient should be placed in a sling and given good analgesics. For type I and II separations, patients can begin range of motion exercises after 7 to 14 days and are likely to return to normal activity after 12 weeks. For type III separations and above, the patient should follow-up with orthopedics within 3-5 days to discuss operative management. They can generally return to full activity after 6 months.
References:
Mazzocca AD, Arciero RA, Bicos J. Evaluation and Treatment of Acromioclavicular joint injuries. Am J Sports Med. 2007 Feb;35(2):316-29.
Montellese P, Dancy T. The acromioclavicular joint. Prim Care 2004; 31:857.
Rudzinski, JP, Pittman LM, Uehara DT. “Shoulder and Humerus Injuries.” In: Tintinalli JE, Stapczynski JS. Tintinalli’s Emergency Medicine. 7th ed. New York: McGraw-Hill; 2011.
