Fractures of the coracoid process: a systematic review.

Background: Although fracture of the coracoid process (CF) used to be considered rare, it is now more commonly encountered due to increased awareness and advances in imaging methods. This review aimed to analyze reported cases of CF to determine its mechanism and appropriate treatment. Methods: PubMed and Scopus were searched using the terms "scapula fracture" and "coracoid fracture." The inclusion criteria were English full-text articles concerning CF that described patient characteristics with appropriate images. The exclusion criteria included cases without appropriate images and those with physeal injury or nonunion. Citation tracking was conducted to find additional articles and notable full-text articles in other languages. Fractures were mainly classified using Ogawa's classification. Results: Ninety-seven studies were identified, including 197 patients (131 men, 33 women; average age 37.0±16.9 years). CF was classified as type I in 77%, type II in 19%, and avulsion fracture at the angle in 5%. Concurrent shoulder girdle injuries included acromioclavicular injury in 33%, clavicular fracture in 17%, acromion or lateral scapular spine fracture in 15%, and anterior shoulder instability in 11%. Among patients with type I CF, 69% had multiple disruptions of the superior shoulder suspensory complex. Conservative treatment was applied in 71% of isolated type I CF, while surgical treatment was applied in 76% of type I CF with multiple disruptions. Although the evaluation methods varied, 60% of patients were followed up for more than 6 months, and the outcomes were generally satisfactory for both conservative and surgical treatments. Conclusion: CF occurred commonly in the age group with higher social activity. The most common fracture type was type I. The possible mechanism of CF is violent traction of the attached muscles, except for avulsion fracture at the angle. Type I CF with multiple disruptions of the superior shoulder suspensory complex requires surgical treatment, whereas conservative care is recommended for isolated type I and type II CFs.