Compliance with applying the Ottawa Ankle Rules
It is reassuring that this study revealed a high compliance rate (87.9%) with the OAR,
with 23.8% of ankle fractures detected on ankle radiography which is higher than reported rates of approximately 15% [4] in the literature.
This demonstrates that clinicians are open to new protocols and are able to use these tools effectively.
This proved especially useful in the larger of the emergency departments,
which is an Australian major trauma center where patient load is high and efficient but safe patient care is paramount.
Concordance Rate with Positive Scoring in the Ankle Rules
The sensitivity of the Ottawa Rules found in this study is 0.96,
with a specificity of 0.15,
and a negative likelihood ratio of 0.29.
This is reasonably consistent with the findings from Bachmann et al’s systematic review in 2003 [5]. These findings reinforce that although the OAR are useful in ruling out an acute ankle fracture,
it cannot effectively predict if an acute fracture is in fact present – therefore necessitating imaging at that point in the clinical process.
Additional Imaging and Modalities
In addition to ankles,
there were 154 instances of a different associated joint imaged which included the knee,
leg,
calcaneum,
foot and toes.
Of these,
20.1% found additional positive or suspicious fractures in areas other than the ankle.
This is an indication that although the Ottawa rules are effective for assessing the ankle joint,
the possibility of injury to other joints should also be considered and appropriately investigated.
There was one case where an occult fracture was diagnosed on MRI.
In this instance,
the patient tested positive for the OAR but negative on plain radiography.
In this instance,
it is encouraging that these rules may assist physicians in their clinical suspicion for occult fractures and go on to pursue additional imaging.
Conclusion
In conclusion,
the benefits of applying the OAR effectively are multiple.
Due to the reduction of ankle radiography,
the patient benefits by having a shorter stay and reduced radiation dose.
In addition,
the hospital benefits by having a quicker turn-around time,
reduced costs and less strain on the imaging department.
Particularly in Australia,
where recent implementation of performance indicators in emergency departments targeting towards a maximum ED triage to discharge time of 4 hours,
decision rules like the OAR may prove invaluable.