You may have never heard of the talus bone, but without it, you would be unable to walk. This bone is located between the base of your leg bones and your heel bone, providing a crucial source of stability so that your legs and feet can support your body weight. A fracture of this bone is called a talar fraction, and it occurs mainly as a result of a car accident or a fall, and with increasing frequency among snowboarders. That’s because the boot used in snowboarding is not rigid, and therefore can’t fully protect your ankle against injuries.

A fracture of the talus causes intense pain, which is accompanied by swelling. You also likely will find you can’t bear weight on the injured ankle. Your sports medicine specialist will ask you about these symptoms, and likely will order an X-ray or even a CT scan to get a better look at your talus and to make a diagnosis.

Treating this fracture can prove challenging, but leaving it untreated, or letting it heal improperly, can cause significant problems down the road, including chronic pain and potentially debilitating arthritis. It could take weeks to months for your fracture to heal. The common treatment approach is a removable boot or a cast to immobilize your foot, and you’ll likely need to use crutches to avoid putting weight on the affected ankle.

If parts of the fractured talus have moved out of alignment, however, surgery will be necessary. A surgeon will make an incision, then move the bones to their correct locations before securing them with a screw. After that, you’ll need to wear a cast until the fracture has healed, then perform physical therapy exercises to regain maximum function of the ankle. Along the way, your doctor may use magnetic resonance imaging (MRI) to take note of how much blood is flowing to the foot; weak blood flow can slow healing and even cause the bone to die, in a condition known as a vascular necrosis or osteonecrosis.

Once you’ve fully healed, the only way to prevent re-injuring your ankle is by avoiding the activity that caused it. Unfortunately, that may mean your snowboarding days are over.