Accuracy of Ottawa Ankle Rules to exclude fractures of the ankle and midfoot in children: a meta-analysis.
OBJECTIVE
The objectives were to conduct a systematic review to determine the diagnostic accuracy of the Ottawa Ankle Rules (OAR) to exclude ankle and midfoot fractures in children and the extent to which x-ray use could be reduced without missing significant fractures.


METHODS
The authors conducted comprehensive searches of electronic databases and gray literature sources. Independent reviewers applied standard inclusion and exclusion criteria. The criterion standard diagnostic test was an ankle and/or foot x-ray or proxy measure to ensure no missed fractures. Standard 2 x 2 tables were constructed. Sensitivities and specificities were pooled using an approximation of the inverse variance; 95% confidence intervals (95% CIs) were calculated using the exact method. Likelihood ratios (LR +/-) and diagnostic odds ratios were combined under DerSimonian and Laird random effects model.


RESULTS
A pooled analysis of 12 studies (N = 3,130) identified 671 fractures (prevalence = 21.4%). Ten studies reported Salter-Harris Type I (SH-I) fractures. The pooled sensitivity was 98.5% (95% CI = 97.3 to 99.2), suggesting that the OAR can be used to rule out a fracture. Four of 10 missed fractures were characterized: 1 SH-I, 1 SH-IV, and 2 "insignificant fractures" (either SH-I or avulsion fractures <3 mm). The pooled estimate for rate of x-ray reduction was 24.8% (95% CI = 23.3% to 26.3%; range = 5% to 44%).


CONCLUSIONS
The OAR appear to be a reliable tool to exclude fractures in children greater than 5 years of age presenting with ankle and midfoot injuries. Employing the OAR would significantly decrease x-ray use with a low likelihood of missing a fracture.
Dowling
Shawn
S
Department of Emergency Medicine, Calgary Health Region, University of Calgary, Calgary, Alberta, Canada. skdowling@gmail.com
Spooner
Carol H
CH
Liang
Yuanyuan
Y
Dryden
Donna M
DM
Friesen
Carol
C
Klassen
Terry P
TP
Wright
R Bruce
RB
D000293:Adolescent; D016512:Ankle Injuries / Q000175:diagnosis* / Q000000981:diagnostic imaging; D002648:Child; D002675:Child, Preschool; D003661:Decision Support Techniques; D005260:Female; D018409:Foot Injuries / Q000175:diagnosis* / Q000000981:diagnostic imaging; D050723:Fractures, Bone / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology; D006801:Humans; D008297:Male; D010146:Pain / Q000175:diagnosis; D010372:Pediatrics / Q000379:methods / Q000592:standards; D011237:Predictive Value of Tests; D015995:Prevalence; D011859:Radiography