This study looked at the use of the Low Risk Ankle rule which basically says in children (ages 3-16) with an acute ankle injury (<72 hours) if the tenderness and swelling is limited to distal fibular and/or adjacent lateral ligaments distal to the tibial ant joint line, no XR is needed to manage the patient.
Part of the rational behind this is that fractures not detected under this rule are minor and do better treated conservatively anyway. I like this principle! Nice to see a study evaluating the cost consequences of the implementation of a CDR. Few CDRs make it to this stage of impact analysis. They implemented the new rule at three different Canadian EDs and compared costs with three similar EDs doing usual practice.
Looked at costs up to 28 days after injury. In the 2000 or so kids in the study they found healthcare costs reduced by $37 per patient at intervention sites. The cost saving was mainly due to leave ankle XRs. As an aside there weren’t any more missed fractures in the intervention group (less in fact!) and use of the rule didn’t cause any extra follow-up.
In my experience most kids turning up to the ED reporting ankle pain get an XR at triage regardless of clinical signs. Those that don’t often end up getting one later from the doc as the parents really came for that above all else- I’m definitely guilty of this! If you were to implement this rule locally you would need to make sure your conservative treatment was similar to Canada, with similar follow-up. The most common treatment was elastic bandage and crutches, but moonboots, casts and splints were used. Follow-up seemed pretty similar to our practice. However for me rather than implementing formally I think this study can just make our decision better informed. Kids with pain but no swelling are the lowest risk of this low risk group. This is evidence their ED care can be safely streamlined without huge investment in the implementation of new rules. The benefit is that we better educate the public in what injuries need XRs and it frees up time and space for other EM care.