Looser zones

Looser zones, also known as cortical infractions or Milkman lines, are wide, transverse lucencies traversing part way through a bone, usually at right angles to the involved cortex and are associated most frequently with osteomalacia and rickets. They are pseudofractures and considered a type of insufficiency fracture. Typically, the fractures have sclerotic irregular margins and are often symmetrical. 


  • pubic rami
  • medial proximal femur
  • lateral scapula
  • posterior proximal ulna
  • ribs

History and etymology

It is named after Emil Looser, Swiss surgeon (1877-1936).

Louis A Milkman (1895-1951) was an American radiologist who described the findings in seminal papers in 1930 and 1934 2.

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Article information

rID: 5666
Synonyms or Alternate Spellings:
  • Looser's zones
  • Looser zones
  • Looser's lines
  • Looser zone
  • Loosers line
  • Loosers lines
  • Loosers zone
  • Loosers zones
  • Osteoid seam
  • Cortical infractions
  • Milkman syndrome
  • Milkman's syndrome

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Cases and figures

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  •  Case 2
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