Extracorporeal shock wave therapy for avulsion fractures of the sublime tubercle of the ulna in high school baseball players: A report of two cases

Injury to the structures of the medial elbow is common among baseball players. The injury can result from repeated valgus stress of the elbow. Several types of injury to the structures of the medial elbow have been reported.1 These injuries cause valgus instability and pain of medial aspect of the elbow during pitch.2e4 Avulsion fractures of the sublime tubercle of the ulna are rare and generally develop after bone maturation in baseball players.5 To the best of our knowledge, there are only three reports in the English orthopedic literature regarding this type of fracture.5e7 According to these reports, conservative treatment is performed initially. As a secondary treatment, bone fixation or ulnar collateral ligament reconstruction is performed when bone union cannot be achieved.6,7 Additionally, avulsion fractures of the sublime tubercle of the ulna are often overlooked, and therefore, are liable to involve non-union. Ulnar collateral ligament reconstruction results in a high rate of successful return to baseball, as reported in a systematic review,8 but no reports have exclusively studied avulsion fractures of the sublime tubercle of the ulna. If patients receive the surgery for an avulsion fracture of the sublime tubercle of the ulna,