[Atypical cause of scapular winging due to exostosis of the scapula].

The most common cause of winging of the scapula is paralysis of the anterior serratus muscle, predominantly because of damage to the long thoracicus nerve. We present a case with a 12 year-old boy, who experienced increasing winging of the scapula over the latest four years. He suffered from minor pain especially when exercising sports. The condition was caused by an osteochondroma on the ventral side of the scapula. We discuss the different causes of winging of the scapula.