Shoulder Instability in Ice Hockey Players Incidence, Mechanism, and MRI Findings Tim Dwyer, MBBS, FRACS, FRCSC a, *, Massimo Petrera, MD a , Robert Bleakney, MD, FRCPC b , John S. Theodoropoulos, MD, MSc, FRCSC a,c INTRODUCTION Ice hockey players are a category of athletes at high risk for traumatic injuries because of the aggressive nature of this contact sport. The most common cause of injury is from body checking or player contact. 1 Furthermore  Reports indicate that players are up to 25 times more likely to be injured in an actual game than during practice. 2–4 Disclosure: The authors listed have identified no professional or financial affiliations for them- selves or their spouse/partner: Tim Dwyer, Massimo Petrera, Robert Bleakney; The authors listed have identified the following professional or financial affiliations for themselves or their spouse/partner: John S. Theodoropoulos is a paid consultant for Smith and Nephew. a Department of Surgery, Women’s College Hospital, University of Toronto Orthopaedic Sports Medicine, 76 Grenville Street, Toronto, Ontario M5S 1B2, Canada; b Department of Medical Im- aging, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario M5G 1X5, Canada; c Department of Surgery, Mount Sinai Hospital, 600 University Avenue, Suite 476C, Toronto, Ontario M5G 1X5, Canada * Corresponding author. E-mail address: tim.dwyer@wchospital.ca KEYWORDS  Ice hockey  Traumatic injury  Hill-Sachs lesions  Magnetic resonance imaging KEY POINTS  The incidence of injury in ice hockey has been shown to increase with the progression from youth hockey, to college, and professional hockey, likely due to increased player contact and body checking.  The reported rate of injury to the shoulder in ice hockey ranges between 8.6% and 21.9%, with 1 prospective study identifying that shoulder sprains and dislocations made up 11% of all injuries.  In this study, 75% of players seen following a traumatic episode of shoulder instability had a Bankart lesion; nearly 80% of these players had a Hill-Sachs lesion.  The high rate of Hill-Sachs lesions may contribute to failure of shoulder stabilization pro- cedures, and may require additional procedures to address the humeral head defect. Clin Sports Med 32 (2013) 803–813 http://dx.doi.org/10.1016/j.csm.2013.07.013 sportsmed.theclinics.com 0278-5919/13/$ – see front matter Ó 2013 Elsevier Inc. All rights reserved.