Pooping duck sign

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The "pooping duck sign" is a radiological finding on barium enema or imaging studies associated with Hirschsprung's disease, where the rectosigmoid region shows a characteristic narrow segment with proximal dilation. Let me search the library for the precise details.
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pooping duck sign radiology medical diagnosis

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https://radiopaedia.org/articles/pooping-duck-sign?lang=us

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The "Pooping Duck" Sign

Modality: Plain radiograph - lateral wrist X-ray Diagnosis indicated: Dorsal triquetral chip (avulsion) fracture

What It Is

The pooping duck sign is a radiological sign seen on a lateral wrist radiograph that indicates a dorsal cortical avulsion fracture of the triquetrum - the second most common carpal fracture after scaphoid fractures, accounting for up to ~15% of all carpal injuries.

How It Gets Its Name

On the lateral wrist view, the overlapping silhouettes of the wrist bones create a duck-like shape:
  • The scaphoid and lunate (superimposed on the volar/palmar side) form the beak and body of the duck
  • The triquetrum (on the dorsal side) forms the rear/tail of the duck
  • The small avulsed bone fragment sitting dorsal to the triquetrum resembles poop being ejected from the duck's rear end
Hence: a "pooping duck."

Clinical Context

FeatureDetails
Fracture typeDorsal cortical chip / avulsion fracture
Bone involvedTriquetrum (proximal carpal row, ulnar side)
MechanismFall on outstretched hand (FOOSH); forced palmar flexion with ulnar deviation
Ligament avulsingRadio-lunato-triquetral ligament (dorsal radiocarpal ligament)
SymptomsDorsal ulnar wrist pain, swelling, tenderness

Imaging

  • Best view: Standard lateral wrist radiograph (may need a pronated oblique view)
  • A small fleck of bone is visible dorsal to the triquetrum
  • CT or MRI can confirm occult fractures or assess ligamentous injuries
As described in Rosen's Emergency Medicine: "Dorsal triquetral chip fractures are best seen on the standard lateral view of the wrist as a small dorsal avulsion fragment, although a more oblique pronated view may be necessary for visualization." - Rosen's Emergency Medicine

Classification (Garcia-Elias)

TypeDescription
1Non-displaced (most common)
2Partially displaced at proximal end
3Partially displaced at distal end
4Completely displaced fragment
5Multiple completely displaced fragments
6Coronal plane fracture with dorsal displacement

Management

  • Dorsal chip fractures: Benign course - immobilize in a short arm volar splint; routine orthopaedic referral within 1-2 weeks
  • Triquetral body fractures (non-displaced): Short arm immobilization; urgent orthopaedic follow-up in 5-7 days
  • Displaced body fractures: ORIF + ED orthopaedic consultation
  • Always assess for associated perilunate/lunate dislocation and ligamentous injuries, especially with body fractures
The sign is a useful and memorable teaching tool because the avulsed fragment is easily overlooked on a busy lateral wrist film - recognizing the "duck" helps radiologists and clinicians avoid missing this subtle but important finding, as reported in the Annals of Medical Science & Research case report.
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