The prevalence of previous serious knee injuries among World Cup elite freestyle skiers

Descriptions

Serious knee injuries increases the risk of early onset of osteoarthritis of the knee. A previous study has shown that 45% of all injuries in World Cup Freestyle skiing are knee injuries. The number of skiers returning to the sport after major knee injuries is unknown, but a previous study has shown that 31% of alpine Olympic racers have sustained an ACL injury during their carreer.   The purpose of this study was to determine the prevalence of previous serious knee injuries among freestyle World Championship skiers. At the FIS Freestyle World Championship 2001 a questionaire for each skier participating was handed out to the team leaders for each team. The biographicals of the skiers, their nationality, disipline (moguls or aerials) and the number of years world cup skiing was registered. The skiers were further asked whether they had ever sustained a former major knee injury defined as a knee injury leaving them out of regular training activity for at least 3 weeks. Given such an injury, we asked under what circumstances the injury happened, whether the skier had been through an MRI scan or artroscopy, the findings and - given the ACL was torn - whether it was reconstructed. The data are analyzed with SPSS software using Crosstabulation/Chi square test and Comparing means/independent t-test. Level of significance has been defined as 0.05.

Results

Completed questionaires of ninety-five skiers (63% response), 55 men and 40 women, age 1836 (mean 24.7) were collected. Twenty-one men (38%) and 24 women (60%) (p=0.035) reported a total of 74 former major knee injuries, ranging from 1 to 5, during their skiing careers. Thirteen men (23.6%) and 12 women (30.0%) (p=0.49) reported a total of 34 former ACL injuries. Three men and 3 women had sustained bilateral ACL ruptures, whereas 3 skiers had had reruptures in one knee. Four of the 34 torn ACLs were not reconstructed. Nineteen of the 34 ACL injuries were combined with cartilage, meniscal or MCL injuries. Five skiers (5.3%) reported to have had a cartilage injury without an ACL injury, 7 skiers (7.4%) reported meniscal tears without ACL or cartilage injuries and 12 skiers (12.6%) reported isolated MCL injuries.

There were not any significant difference between the genders in the prevalence of any of the specific types of injury. Furthermore, the prevalence of knee injuries as a total, as well as of each specific type of injury, was not significant different for the two disciplines moguls and aerials. The mean number of years World Cup skiing in the group of injured skiers (5.73 years) was significant higher than in the group of non-injured skiers (3.23 y) (p<0.001).

Nearly half of the responding FIS freestyle World Championship skiers had previously sustained one or more major knee injuries and still returned to such a high level of athletic performance. One fourth of the skiers had sustained one or more former ACL ruptures. The prevalence of previous serious knee injuries over all was significantly higher among female than among male skiers, although the prevalence of any specific type of knee injury, such as former ACL injuries, did not show significant difference between genders.