Acute ankle sprains
– Common complaint in ED
– Ankle and C-spine radiographic series are the two most commonly ordered musculoskeletal x-rays in ED
– Approx 5 million ankle x-rays in Canada and US

Estimated $500 million in professional and technical cost of performing X-Rays. There is no widely accepted guidelines for the use of radiography in the ankle injuries.

Decision rules used to determine if radiographs are indicated in foot ankle/foot. Develop decision rules that are 100% sensitive for detecting clinically significant fractures of the ankle and midfoot

Zones of Ankle
– Malleolar zone- distal 6cm of tibia and fibula and talus
– Midfoot zone- navicular, cuboid, cuneiforms, anterior process of calcaneus, and base of the 5th metatarsal

Goal: to develop decision rules that were 100% for detecting clinically significant fractures on each the ankle injury patients. Conducted using 21 ED physicians at 2 Ottawa hospitals.

– 750 pts presenting with acute blunt injuries to ankle (twisting injuries, falls from height etc)

32 Predictor variables were assessed using kappa coefficient for Ankle and Foot Fx’s.

– specific points of tenderness
– ability to bear weight for at least 4 steps

Estimate the probable fracture under x-ray.

-ankle and midfoot zones

 

Physicians would’ve missed 29% of fractures on the ankle series if the cutoff point for ordering radiographs had been their own predictive probability of 50% for a fracture. Two decision rules derived by multivariate recursive partitioning techniques that would’ve identified 100% of the fractures.

Decision Rule #1
Ankle radiographic series was only necessary if the pt had pain near the malleoli and one or more of these findings.

Decision Rule #2
Foot radiographic series was only necessary if the pt had pain in the midfoot and bone tenderness at the navicular bone, the cuboid, or at the base of the 5th metatarsal.

 

1052 pts; Refinement of original rules
– Univariate and recursive partitioning analyses

 

Stiel IG, Greenberg, Gary H, et al. Decision Rules for the use of Radiography in Acute Ankle Injuries: Refinement and Prospective Validation. JAMA. 1993; 269:1127-1132

Stiel et al. Use of Radiography in Ankle Injuries. Ann Emerg Med. April 1992;21;384- 390

Heyworth J. Ottawa Ankle Rules for the Injured Ankle. BMJ.2003; 326:405-6

Bachman, LM, Kold E, et al. Accuracy of Ottawa Ankle Rules to Exclude Fracture of the Ankle and Mid-foot: Systemoc Review