Foot Fracture Workup

Updated: Aug 03, 2017
  • Author: Robert Silbergleit, MD; Chief Editor: Trevor John Mills, MD, MPH  more...
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Workup

Imaging Studies

Plain-film radiography

Ottawa foot rules are a tool that predicts significant midfoot fractures. They are guidelines used to determine whether radiographs are necessary. [12] If any of the following are present, a radiograph is required: point tenderness over the base of fifth metatarsal; point tenderness over the navicular bone;iInability to take 4 steps, both immediately after injury and in the ED.

Although developed and validated in adults, the Ottawa foot rule also appears to be a reliable tool to exclude fractures in children 5 years of age and older. [15] When performed, a systematic approach to reading foot radiographs is important and reduces the risk of missing important injuries. [16]

In a study by Pires et al, the Ottawa ankle rules showed a high reliability for determination of when to take radiographs in patients with foot or ankle sprains. Weight-bearing inability was found to be the most important isolated item to predict the presence of a fracture (69.4% sensitivity, 61.6% specificity, 63.1% accuracy, 21.9% positive predictive value, and 93% negative predictive value). Orthopedic surgeon subjective analysis had a 55.6% sensitivity, 90.1% specificity, 46.5% positive predictive value, and 92.9% negative predictive value. The general orthopedic surgeon opinion accuracy was 85.4%. The Ottawa ankle rules presented 97.2% sensitivity, 7.8% specificity, 13.9% positive predictive value, 95% negative predictive value, and 19.9% accuracy. [17]

Other imaging modalities

Bone scanning, CT scanning, MRI, and ultrasonography may help diagnose certain foot fractures that are occult on plain film radiography. [18, 19] Although recent anecdotal reports and small diagnostic trials suggest that ultrasonography may someday have a role in routine assessment of acute foot fractures, [20, 21] second-line imaging studies generally do not need to be performed while the patient is in the ED and are usually ordered only after consultation with a foot surgeon.

Bedside ultrasonography in addition to Ottawa Foot and Ankle Rules (OFAR) in acutely injured patients was found to reduce the number of ordered x-rays and length of stay in ED in patients 18 years and older. The sensitivity of US in detecting foot and ankle fractures was 100%, and the specificity of OFAR increased from 50% to 100% with the addition of US. The negative predictive value and positive predictive value were both 100%. [22]