gms | German Medical Science

Introduction: Spiral fractures of the humerus in ball throwers are rare clinical entities and were given the name “ball-thrower's fractures”. Ball-thrower's fractures have never been reported in dodgeball players. We present two cases of spiral fractures of the humerus in two male dodgeball players.

Material and methods: 2 Case Reports

Results: Case No. 1: Our first patient is 35 year old right handed real estate broker. He felt his right arm break while performing a sidearm throw with full effort.The radiographs showed a moderately displaced spiral fracture of the middle third of his right humerus. The patient was treated conservatively with a cast. Follow-up radiographs taken four months after the injury showed good bone union in near anatomical position with callus formation.

Case No. 2: The second patient is a 35 year old right handed accountant. He experienced increasing pain in his dominant arm while performing multiple full effort throws in two consecutive dodgeball matches. At the beginning of the third game, he heard a loud snapping sound when he was trying a hard sidearm throw. The radiographs showed a displaced spiral fracture of the middle third of his right humerus.

Conclusion: With regards to the etiology of ball thrower’s fractures, several theories have been published. Chao et al. highlighted an excessive torsional moment. Since a sidearm throw is performed with an abducted and externally rotated arm this theory might apply to our patients. Polu et al. saw a strong correlation between ball thrower’s fractures and repetitive stress. At least one of our patients also suffered from repetitive stress after having already played two dodgeball matches before fracturing his humerus during the third match on the same day.

In our experience both factors seem to contribute to the development of a spiral fracture of the humerus and therefore dodegball can be a dangerous sport for relatively untrained amateurs that attempt full effort sidearm throws repetitively.