Ankle injuries are on the rise with snowboarders. Sometimes the injury isn’t seen on X-rays and some other type of imaging is needed. MRIs will show unusual fractures but may not show the extent of the damange. In those cases, CT scans are better.
It may be best to see an orthopedic surgeon. The doctor will be able to assess the injury and advise you on the next step. Chronic pain of this type can be caused by a fracture that never healed. Loss of blood supply can lead to bone necrosis (death). It’s best to have the injury re-checked at this time.