Ottawa ankle rules

Ottawa ankle rules:

1.An ankle x-ray is required only if there is any pain in malleolar zone and any of these findings:

a.Bone tenderness along the distal 6 cm of the posterior edge of the tibia or tip of the medial malleolus, OR
b.Bone tenderness along the distal 6 cm of the posterior edge of the fibula or tip of the lateral malleolus, OR
c.An inability to bear weight both immediately and in the emergency department for four steps.

2.A foot x-ray is required if there is any pain in the midfoot zone and any of these findings:

a.Bone tenderness at the base of the fifth metatarsal (for foot injuries), OR
b.Bone tenderness at the navicular bone (for foot injuries), OR
c.An inability to bear weight both immediately and in the emergency department for four steps.


In medicine, the Ottawa ankle rules are a set of guidelines for doctors to aid them in deciding if a patient with foot or ankle pain should be offered X-rays to diagnose a possible bone fracture. Before the introduction of the rules most patients with ankle injuries would have been X-rayed. However only about 15% of X-rays were positive for fracture, other patients had sprains or other injuries. As a result many unnecessary X-rays were taken, which was costly, time consuming and a possible health risk.


Utility of the Ottawa rules:

The rules have been found to have a very low rate of false negatives. Evidence in systematic reviews supports the Ottawa ankle rules as an accurate instrument for excluding fractures of the ankle and mid-foot. The instrument has a sensitivity of almost 100% and a modest specificity, and its use should reduce the number of unnecessary radiographs by 30-40%.
Among the studies in the original review their research reported that the test was 100% sensitive and reduced the number of ankle X-rays by about 35%. A second trial with a larger number of patients confirmed these findings.[4] Subsequently, a multi-centre study was done that explored the feasibility of implementing the rules on a wider scale.Unfortunately, teaching the rules to patients does not appear to help reduce presentation to hospital.

History:

The Ottawa ankle rules were developed by a team of doctors in the Urgent Care department of the Ottawa Hospital in Ottawa, Canada.[3] Since the rules were formulated in Ottawa they were dubbed the Ottawa ankle rules by their creators a few years after their development, a title that has stuck.[4] In this respect, the naming of the rules is similar to that of the Bristol stool scale or the Glasgow Coma Scale (GCS), which also take their names from the cities in which they were formulated.


Conclusion: Evidence supports the Ottawa ankle rules as an accurate instrument for excluding fractures of the ankle and mid-foot. The instrument has a sensitivity of almost 100% and a modest specificity, and its use should reduce the number of unnecessary radiographs by 30-40%. (BMJ 326 : 417 doi: 10.1136/bmj.326.7386.417 (Published 22 February 2003)