Ankle Injury – Sprained or Fractured?

Kimi ChaterUncategorized

Photo courtesy of Marmot, makers of fine outdoor gear and suppliers of our Peak Safety Medic gear!

Each year ACC processes around 50,000 new ankle injury claims from sport and recreation alone making it one of the most common injuries across the country. While recognising ankle trauma is fairly straight forward, deciding whether the patient has a sprain or a fracture and whether they require an X-Ray is much more complicated.

Fortunately, a few on to it Doctors at the Ottawa Health Research Institute have developed a set of rules to guide us. The Ottawa Ankle Rules can be applied to anyone over 2 years old who has ankle pain with additional caution being advised when assessing patients under 18 years. The rules have been validated in numerous populations with a high level of accuracy. They appear to be more accurate at ruling fractures out (useful when assessing patients in wilderness settings) than they are of definitively diagnosing fractures. This ties in nicely with a cautious approach to fracture assessments.

Advice

  • If ankle pain is present and there is tenderness over the posterior 6 cm or tip of the posterior or lateral malleolus, then an ankle X-Ray is indicated.
  • If midfoot pain is present and there is tenderness over the navicular or the base of the fifth metatarsal, then a foot X-Ray is indicated.
  • If there is ankle or midfoot pain and the patient is unable to take four steps both immediately and in the emergency department, then X-Ray of the painful area is indicated.

These rules appear, in our experience to capture virtually all ankle and foot fractures. The ability to weight bear alone is not a definitive indicator of fractures as we have seen people run for many kilometres on fractured ankles if they are determined enough. In these cases the point tenderness is the important assessment tool.

Management of suspected ankle fractures in the outdoor/sporting environments.

  • Splint the injured ankle and transport for X-ray
  • RICE plan (Rest, Ice, Compression, Elevation)
  • Pain medication where appropriate

The Ottawa ankle rules are designed to reduce the number of unnecessary ankle X-Rays in emergency departments. Without an X-Ray there can be no definitive way to rule out fractures, however patients that don’t meet the criteria in these rules are highly unlikely to have a clinically significant fracture.

The following precautions should be noted:

If the patients is combative, distracted or has a lowered level of consciousness then they may not be reliable witnesses of their ankle pain. If there is significant swelling or loss of sensation then this may mask point tenderness and make assessment difficult. Any patient who does not meet the criteria for a fracture should be encouraged to seek a reassessment if the pain or ability to walk has not improved in 5-7 days.