Epidemiology and Risk Factors of Humerus Fractures Among Skiers and Snowboarders

Derek Chase, Surgical Senior Major, Class of 2008

Advisors:  Benjamin Bissell, Robert J. Johnson, Adam Shafritz, Carl Ettlinger

University of Vermont Department of Orthopaedic Surgery and Rehabilitation

 Abstract

 Background: The incidence of humerus fractures while participating in snowboarding and skiing is undefined. Very little is known about the risk factors associated with these fractures.

Hypothesis: Snowboarders are at increased risk for sustaining humerus fractures when compared to skiers. In addition, the types of fractures, laterality and risk factors differ between the two groups.

Study Design: Case-control study.

Methods: At a major ski area clinic, 318 humerus fractures were evaluated over 34 seasons.  Radiographs were classified according to the AO and Neer systems. Patient data were analyzed and compared to a control population of uninjured skiers and snowboarders to determine incidence and risk factors.

Results: The incidence of humerus fractures among snowboarders (0.062 per 1000 snowboarders days) was significantly higher than that of skiers (0.041 per 1000, p<0.05).  Skiers were more likely to sustain proximal fractures, and snowboarders were relatively more likely to sustain diaphyseal and distal fractures (p<0.05).  6.56% of glenohumeral dislocations were associated with proximal humerus fractures among skiers (1.7% among snowboarders). Snowboarders who lead with their left foot were more likely to fracture their left humerus (p=0.023). Helmet use and gender were not risk factors for humerus fractures among both skiers and snowboarders.  Jumping was involved in 28.3% of humerus fractures among snowboarders and in 5.4% among skiers. Skiers with humerus fractures were more skilled, older, and fell less frequently than controls. Snowboarders were less skilled, younger and fell at a similar rate compared to controls.

Conclusions: Snowboarders are at significantly higher risk of sustaining humerus fractures compared to skiers.  In skiers, humerus fractures show no laterality and most often involve the proximal humerus.  In contrast, snowboarders more often fracture their left humerus at the diaphysis.