ACL Injury Incidence Among Male and Female Professional Alpine Skiers

abstract & commentary

Synopsis: ACL injury rates are similar in male and female professional alpine skiers.

Source: Viola RW, et al. Anterior cruciate ligament injury incidence among male and female professional alpine skiers. Am J Sports Med 1999;27(6):792-795.

In an effort to further outline gender-based anterior cruciate ligament (ACL) injury rates, Viola and colleagues from the Steadman Hawkins Sports Medicine Clinic retrospectively reviewed knee injury rates in professional alpine skiers. Using a database composed of 7155 ski patrollers or instructors (4537 men, 2618 women), Viola et al followed injury rates based on documentation through workmen’s compensation reporting between 1991 and 1997 at one ski resort. The men skied an average of 110 days per year, with women skiing an average of 89 days per year. The incidence of ACL disruption was 4.2 injuries per 100,000 skier-days in men and 4.4 injuries per 100,000 skier-days in women. A total of 31 ACL injuries were noted, 21 in men and 10 in women. Interestingly, demographics were statistically different for age of the participants, with women averaging 26 years and men averaging 33 years (P = 0.013). Although the number of skier-days between men and women also was significantly different, injury rates were normalized per skier-days to correct for this.

Viola et al hypothesized the similarity in injury rates is related to the mechanism of injury in skiing being valgus with internal rotation, or a direct anterior force generated by the ski boot. Whereas there are well-documented differences in injury rates between NCAA men and women collegiate basketball and soccer players, their mechanism of injury is usually sudden deceleration, twisting, or hyperextension. Although the age differences are significant, Viola et al reference a previous study by Greenwald et al that noted no age-related differences in injury incidence in skiers.1 In that study, however, gender-specific injury rates were different in skiers. Nonetheless, Viola et al report the first gender-specific ACL injury incidence study in a controlled population of alpine skiers revealing relatively similar injury incidence of ACL tears in men and women.

Comment by Robert C. Schenck, Jr., MD

This article is another excellent addition to the knowledge base of gender-specific ACL injury rates. Using the "journeyman" professional skier (ski instructor or patroller) is a unique way to have a captured population where injuries will be accurately reported and documented. Thus, the days of exposure, numbers of participants, and injuries reported will be accurate. In this population, the male skier is older than the female skier but injury rates are equal. Viola et al noted the physical conditioning and skill level of both the men and women was excellent based on preseason evaluations.

The similar injury rates are probably best explained by the level of skiing performed. As Viola et al noted, "Most professional skiers spend a significant amount of their time skiing below their ability level." It would be interesting to evaluate NCAA injury rates between males and females in alpine skiing as performed by Arendt and Dick in soccer and basketball.2 Possibly, during competition, and skiing daily at one’s skill level, injury rates between men and women may differ as seen in previous studies. Further study is needed in this interesting area of sports injury.

References

1. Greenwald RM, et al. Significant gender differences in alpine skiing injuries: A five year study. In: Mote CDJ, Johnson RJ, eds. Skiing Trauma and Safety: Tenth International Symposium. Philadelphia, Pa.: American Society for Testing and Materials; 1996:36-44.

2. Arendt E, Dick R. Knee injury patterns among men and women in collegiate basketball and soccer. NCAA data and review of literature. Am J Sports Med 1995;23:694-701.

The rate of ACL tears in female skiers compared to male skiers was:

a. half less.

b. twice more.

c. equal.

d. sevenfold.