Differential Diagnosis for Wrist Pain after a Fall

The patient's complaint of wrist pain after falling on an outstretched hand, tenderness over the anatomic snuffbox, and normal X-rays suggests several possible diagnoses. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • C. Scaphoid fracture: This is the most likely diagnosis given the mechanism of injury (fall on an outstretched hand) and the location of tenderness (anatomic snuffbox), which is a common site for scaphoid fractures. Scaphoid fractures can be occult and not visible on initial X-rays.

• Other Likely Diagnoses

  • A. De Quervain’s tenosynovitis: Although less likely given the acute trauma, De Quervain's tenosynovitis involves the tendons on the thumb side of the wrist and can cause pain in the area of the anatomic snuffbox. It's more commonly associated with repetitive motion or strain rather than a single traumatic event.
  • D. Wrist sprain: A wrist sprain could result from a fall on an outstretched hand and might not show obvious deformity or abnormalities on X-rays. However, the specific tenderness over the anatomic snuffbox points more towards a fracture or a specific tendon issue.

• Do Not Miss Diagnoses

  • B. Colles fracture: Although the question stem mentions no obvious deformity and normal X-rays, a Colles fracture (a type of fracture at the distal end of the radius) is a significant injury that could have serious consequences if missed. Some Colles fractures might not be immediately apparent on X-rays, especially if they are nondisplaced or if the patient is seen very early after the injury.

• Rare Diagnoses

  • Other rare diagnoses could include fractures of other carpal bones (e.g., lunate, triquetrum), ligamentous injuries, or even a radial styloid fracture. However, these would be less likely given the specific presentation and would typically require additional symptoms or findings for consideration.