Trethowan sign

The Trethowan sign is used to diagnose slipped capital femoral epiphysis (also called slipped upper femoral epiphysis). In this sign, the line of Klein passes above the femoral head.

It is best done on both AP and true lateral projections. On the AP view of a normal hip, the Klein line intersects a small portion of the lateral capital epiphysis.

In typical posterior displacement of the capital epiphysis, the line intersects a smaller portion of the epiphysis or does not intersect it at all - the positiveTrethowan sign.

It is one of the signs that may help in the initial phase (mild slip) with typical posterior displacement, where AP radiographic findings are known to be subtle.

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Article information

rID: 22755
Section: Signs
Tags: stub, cases
Synonyms or Alternate Spellings:
  • The Trethowan's sign
  • Trethowan sign
  • The Trethowan sign
  • Trethowan´s sign

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