Ski season is behind us, but that doesn’t mean it’s not a good time to talk about how to prevent ski injuries next season. Anterior Tibial Spine Fractures, once thought to occur mostly in children, are now being recognized more in adult skiers.
What is an Anterior Tibial Spine Fracture?
Anterior tibial spine fractures (ATSFs) are avulsion fractures of the ACL insertion onto the tibia. In these fractures the ligament avulses (pulls off) the bone from the tibia instead of tearing the ligament itself. This is similar to pulling a tree out by the roots. These fractures have been well described in children, but recent research is showing ATSFs to be more common in adults than previously thought.
What does this have to do with skiing?
Skiing is a high risk sport for injuring the Anterior Cruciate Ligament (ACL) or creating an ATSFs in children. However at the University of Vermont orthopedic clinic at the Sugarbush Ski Resort many of the ATSFs were identified in adults. This initiated a study by Robert Johnson, MD, and Ben Albertson, MD, to investigate the epidemiology for ATSFs and risk factors for ACL tears in skiers.
The UVM ski injury research team investigated ACL tears and ATSFs among Sugarbush skiers from the 1991-92 ski season through the 2012-13 ski season. Over the course of the study period 1,723 ACL injuries were identified and 51 were ATSFs. A control group of 2,763 skiers over the same time period were used to look for risk factors for ACL injury.
What was found?
The data is still being reviewed. Preliminary epidemiology results identified 74.5% of our ATSFs were in adults (age 17+), but the incidence of ATSF’s was about twice as high in children (age 0-10), and adolescents (age 11-16) as it was in adults.
How does that make sense?
Despite the fact that the majority of our ATSF’s occurred in adults, the incidence is higher in children because the skier population at risk is largely adults. Put another way, the proportion of skiers at Sugarbush who are adults is much larger than the proportion that is children and adolescents. Therefore, even though ATSFs are more common in children we see them more in adults purely based on the greater number of adult skiers at risk.
Who is most at risk of ATSF or tearing their ACL while skiing?
Again we have not finalized our data, but our results are suggesting that there are a number of risk factors that help us predict who is at the greatest risk of injuring their ACL. Those most at risk appear to be female skiers (many studies have shown females to have a greater risk of ACL injury than males), and less experienced skiers. The variables related to skier experience and ability include: fewer prior seasons skied, lower skier type, and not owning your own equipment.
What does this mean?
Skiing is a very fun but dangerous sport especially for the ACL. It is a popular winter pastime and we are defining those individuals most at risk of ACL injury. With this information we hope to be able to target this group in the future with preventative measures to keep everyone on the slopes safe. Stay tuned for final results and data publication.
Ben Albertson MD, Robert Johnson MD, and James Slauterbeck MD are orthopedic surgeons at the University of Vermont Medical Center.