Gilula three carpal arcs

Last revised by Dr Jeremy Jones on 18 Sep 2021

Gilula three carpal arcs refer to the carpal 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 indicate 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 (1942-2014) in 1979 3,5

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Figure 1: Gilula carpal arcs
    Drag here to reorder.
  • Figure 2: Gilula's arcs
    Drag here to reorder.
  • Figure 3: disrupted carpal arcs of Gilula
    Drag here to reorder.
  • Updating… Please wait.

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

     Thank you for updating your details.