The coracoid process serves as a crucial anchor for multiple tendon and ligamentous attachments in the shoulder. While glenohumeral and labral pathology are more commonly implicated in shoulder injuries, the coracoid process can also be a primary pain generator within the shoulder. This educational poster will address normal coracoid anatomy and development, as well as pathologic conditions affecting the coracoid in the pediatric population, including fractures, infection, and neoplasm. The coracoid is a beak-like projection that extends anteriorly from the ventral scapula. It serves as the origin for the pectoralis minor, coracobrachialis, and short head of the biceps. Ligamentous attachments extend from the coracoid to the clavicle (coracoclavicular ligaments), acromion (coracoacromial ligament), and humerus (coracohumeral ligament). Additionally, the transverse scapular ligament attaches to the coracoid base. The growth plate at the coracoid base is considered a “bipolar growth plate” and is made up of the primary ossification centers of the coracoid and the adjacent ventral scapula, similar to the tri-radiate cartilage of the acetabulum. The coracoid appears within the first year of life with fusion of the coracoid base growth plate occurring by age 14 to 15. Physeal injuries occur at the base of the coracoid with imaging characteristics similar to other more typical locations (i.e. the proximal humerus in Little Leaguer’s shoulder). Key features include physeal widening with irregular bony margins, thought to be secondary to chronic repetitive pull from the attached musculature. Additionally, coracoid fractures occur in acute trauma and can be easily overlooked as they are frequently associated with other fractures. Direct blunt trauma by either an external object or the humeral head are associated with fractures of the base of the coracoid. Avulsions of the coracoid tip are seen with acromioclavicular separations with injury to the cocacoclavicular ligaments, more commonly seen in the pediatric population as the ligaments are relatively stronger than their osseous attachments. While tumors of the coracoid are rare and more commonly occur in adults, primary tumors of the coracoid are seen in the pediatric population with case reports of osteoid osteomas, osteoblastomas, giant cell tumors, and aneurysmal bone cysts. Awareness of pathology affecting the coracoid process is helpful to the radiologist and clinician caring for the child with shoulder pain.
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Meeting name:
SPR 2018 Annual Meeting & Postgraduate Course
, 2018
Authors:
Sharp Paige,
Braithwaite Kiery,
Marshall Kelley
Keywords:
Physis,
Fracture,
Osteoid osteoma