Fracture mimics

  • Unfused epiphyseal plate (= growth plate), e.g. in the elbow and shoulder (see fig. 3b, section Fracture Types).
  • Unfused apophysis (= ossification center where tendon inserts). The apophysis at the base of metatarsal V is a notorious fracture mimic.
  • Accessory ossification centers, particularly in the feet (fig. 9)

In all the above-described mimics, it is crucial to evaluate older images. Additionally, when in doubt, it is useful to consult a book of reference describing the normal variations of the skeletal system (e.g. Keats, T.E.; Atlas of Normal Roentgen Variants That May Simulate Disease). Each Emergency Assistance department should have such a (thick!)reference book.

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Os trigonum.
Os trigonum.

Figure 9. Lateral ankle image with an accessory ossification center dorsal from the talus; the os trigonum.