Acromial apophysitis in a 13-year-old adolescent boy: a common condition in an uncommon location.

OBJECTIVE: Traction apophysitis is a common condition in physically active and skeletally immature adolescents. This case study describes the clinical presentation and plain film imaging of traction apophysitis of the acromion process of the scapula. CLINICAL FEATURES: A physically active 13-year-old adolescent boy presented to a chiropractic physician with an acute onset of moderate shoulder pain. Plain film radiographs of the shoulder were performed that revealed fragmentation, sclerosis, and irregularity of the left acromial apophysis. INTERVENTION AND OUTCOME: The patient was treated with conservative therapy for 10 weeks, with complete resolution of symptoms. Follow-up radiographs 9 weeks later revealed no radiographic change in the appearance of the apophysis; however, clinical symptoms were absent. The apophyseal growth cartilage is the most vulnerable site in the muscle-tendon unit in the skeletally immature patient and is more susceptible to very small avulsion fractures. Repetitive microtrauma following chronic overuse at a tendon insertion site in a skeletally immature patient may result in traction apophysitis.
CONCLUSIONS: Acromial apophysitis should be included in the differential diagnosis when presented with a young active patient with shoulder pain. Early treatment with restriction of activities is important in the prevention of permanent injury to the acromial cartilaginous growth plate. This case demonstrates that a prompt diagnosis can be made with a careful history, physical examination, and conventional imaging.