Gilula three carpal arcs

Gilula three carpal arcs refer to the alignment described on posteroanterior or anteroposterior wrist radiographs and are used to assess normal alignment of the carpus:

  • first arc: is a smooth curve outlining the proximal convexities of the scaphoid, lunate and triquetrum
  • second arc: traces the distal concave surfaces of the same bones
  • third arc: follows the main proximal curvatures of the capitate and hamate

Alignment

  • carpal bones have smooth and rounded edges to varying degrees, lines joining these convexities form arcs, when major convexities are used in drawing
  • there should be no step-offs in the contour of the arcs, except for two normal variants 4
    • a triquetrum that is shorter than the lunate creates a step-off in the first arc but there is still a normal second arc
    • "bi-lobed" appearance of second carpal arc in lunate type II morphology
  • disrupted arc may indicated a ligamentous injury or fracture at the site of the broken arc

History and etymology

The concept of three radiographic arcs was first proposed by Louis A Gilula in 1979 3

Upper limb anatomy
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Article Information

rID: 25518
Tag: cases
Synonyms or Alternate Spellings:
  • Three carpal arcs of gilula
  • Carpal arcs
  • Gilula's three carpal arcs

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Cases and Figures

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    Normal wrist -  A...
    Figure 1: Gilula carpal arcs
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    Disrupted carpal ...
    Figure 2: disrupted carpal arcs of Gilula
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