Erlenmeyer flask deformity

Erlenmeyer flask deformity (EFD), also known as metaphyseal flaring, refers to a radiographic appearance typically on a femoral radiograph demonstrating relatively reduced constriction of the diaphysis and flaring of the metaphysis as a result of undertubulation

The name refers to the resemblance to a flat bottomed titration flask used by chemists, (known as a conical flask in British English.)

It has been classically used with reference to the distal ends of the femora, however it is also seen in the proximal humeri, tibiae, and the distal radii and ulnae 4

The causes can also be remembered with the mnemonics AP OF DR GHLNCHONG or Lead GNOME.

The conically-shaped flask with a wide base and short narrow neck was created by the German chemist Emil Erlenmeyer (1825–1909) in 1860 3.

Article information

rID: 1298
Section: Gamuts, Signs
Tag: refs, refs
Synonyms or Alternate Spellings:
  • Metaphyseal flaring
  • Erlenmeyer flask deformities
  • Erlenmeyer flask deformity
  • Erlenmeyer flask deformity (EFD)

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Figure 1: photograph - Erlenmeyer flasks
    Drag here to reorder.
  • Case 1: osteopetrosis
    Drag here to reorder.
  • Case 2: Gaucher disease
    Drag here to reorder.
  • Case 3: Pyle disease
    Drag here to reorder.
  • Case 4: rickets
    Drag here to reorder.
  • Case 5: pure red cell aplasia
    Drag here to reorder.
  • Case 6: hereditary multiple exostoses
    Drag here to reorder.
  • Case 7: unknown
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.