Epidemiology of Female Youth Ice Hockey Injuries Presenting to United States Emergency Department’s from 2007 to 2016

OBJECTIVES: Female youth ice hockey players are an overlooked population. No national study has established incidence rates for injuries in female youth ice hockey. The objective of this study was to establish incidence rates by injury location, diagnosis, and mechanism of injury using USA Hockey sanctioned age divisions. METHODS: The National Electronic Injury Surveillance System (NEISS) was queried for all ice hockey injuries (product code 1279) from January 1, 2007 to December 31, 2016. Cases involving players over the age of 19 and males were excluded. Each injury’s narrative text field was reviewed to determine mechanism of injury. Data was analyzed using (IBM®, v24). Comparisons of incidence by age were made using student’s two sample t-test with 95% confidence interval. Trend analyses were performed using a linear regression. USA Hockey membership statistics were used to establish population at risk and calculate incidence rates. All incidence rates were reported per 10,000 person-years. RESULTS: A total of 384 patients, representing an estimated 10,398 ice hockey-related injuries, presented to NEISS-participating United States emergency departments. During the study period, female youth ice hockey players increased significantly from 44,678 in 2007 to 57,792 in 2016 (p=3.9x10-5, R-squared=0.89, ß =0.94). The overall number of injuries, however, only slightly increased from 992 in 2007 to 1,042 in 2016 (p=ns). Thus, the incidence rate (IR) of injuries fell from 222.1 to 180.2 during the study period. The most commonly injured body parts were the head (n=3048, IR=554.5), trunk (n=1399, IR=256.4), knee (n=1127, IR=169), shoulder (n=704, IR=153.3) and ankle (n=591, IR=120.2). The most common diagnoses were strain/sprain (n=2002, IR=417.7), contusion (n=1877, IR= 348), internal organ injury (n=1863, IR=320), concussion (n=1112, IR=218) and fracture (n=1255, IR=202). The top mechanisms of injury were player-to-player contact (n= 3016, IR=535), falls (n=2249, IR=380.9), and contact with boards (n=942, IR=165.8). The incidence rate of injuries increased with age; The 0-8, 9-10, 11-12, 13-14, 15-16 and 17-19 age divisions had IR’s of 24, 84, 226, 381, 360, and 750, respectively. The player-to-player mechanism of injury also increased with age. The largest IR gap between ages fell between the 11-12 and 13-14 age groups, similar to what has been observed in male ice hockey studies. Player-to-player contact is the leading mechanism of injury in all age groups except the 0-8 age group. Head injuries increased with age division: 0-8 (n=15, IR=1), 9-10 (n=153, IR=17.4), 11-12 (n=598, IR=67.2), 13-14 (n=885, IR=115.1), 15-16 (n=650, IR=121.6) and 17-19 (n=746, IR=232.2). The two most common diagnoses of head injuries were concussion (36%) and internal organ injury (61%), both of these diagnoses increasing with age. In fact, concussion diagnosis increased significantly between each age group (p<0.01). CONCLUSION: We established the first collection of injury incidence rates for female ice hockey gleaned from a national database. Though body checking is illegal at all levels of women’s ice hockey, player-to-player contact prevailed as the leading mechanism of injury in all but the 0-8 age division. It was also the leading mechanism for the most common injury sites, including the head. This study laid bare an unspoken but long understood fact of the girl’s game that body checking is common and major contributor to the game’s injury burden.