Epidemiology and Risk Factors of Humerus Fractures among Skiers and Snowboarders

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 with skiers. In addition, the types of fractures, laterality, and risk factors differ between the 2 groups. Study Design Case-control study; Level of evidence, 3. 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 with that of 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 snowboarder days) was significantly higher than that of skiers (0.041 per 1000, P < .05). Skiers were more likely to sustain proximal fractures, and snowboarders were relatively more likely to sustain diaphyseal and distal fractures (P < .05). Of glenohumeral dislocations, 6.56% 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 = .023). Helmet use and gender were not risk factors for humerus fractures among either skiers or 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 with controls. Conclusion Snowboarders are at significantly higher risk of sustaining humerus fractures than skiers. In skiers, humerus fractures show no laterality and most often involve the proximal humerus. In contrast, snowboarders more often fracture the left humerus at the diaphysis.