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Difficulty: MediumOrthopedic Surgery

Following a fall onto an outstretched hand during a snowboarding competition, a collegiate athlete presents with worsening right wrist discomfort. The patient specifically notes a deep ache near the base of the thumb that is exacerbated by gripping objects. On physical examination, there is mild edema and focal tenderness when palpating the depression between the extensor pollicis longus and the extensor pollicis brevis tendons. Range of motion at the radiocarpal joint is slightly limited by pain. Standard four-view radiographs of the wrist reveal no cortical step-offs, radiolucent lines, or malalignment. Which of the following is the most appropriate next step in management?

  1. Immobilize the wrist in a thumb spica splint and schedule a repeat evaluation in 7 to 14 daysAnswer
  2. B
    Discharge the patient with a supportive elastic bandage and advise early range-of-motion exercises
  3. C
    Administer a local corticosteroid injection into the first dorsal compartment
  4. D
    Perform immediate open reduction and internal fixation to prevent avascular necrosis
  5. E
    Prescribe prophylactic oral antibiotics and arrange for an outpatient magnetic resonance imaging scan

Answer

Immobilize the wrist in a thumb spica splint and schedule a repeat evaluation in 7 to 14 days
The clinical presentation of anatomic snuffbox tenderness following a fall on an outstretched hand is highly suspicious for a scaphoid fracture. Because initial radiographs can be falsely negative in up to 20% of acute cases, the standard of care for a clinically suspected scaphoid fracture with negative initial imaging is to assume a nondisplaced fracture is present. The patient must be placed in a thumb spica splint to immobilize the joint, followed by repeat radiographs in 7 to 14 days. By that time, osteoclastic bone resorption at the fracture site will typically make the radiolucent line visible on X-ray. Prompt immobilization is critical to prevent avascular necrosis and nonunion due to the scaphoid's tenuous retrograde blood supply.

Step-by-Step Solution

1
Analyze the mechanism of injury and physical exam findings.
The patient had a fall on an outstretched hand (FOOSH) and exhibits focal tenderness in the anatomic snuffbox.
These findings are the classic hallmark of a scaphoid fracture. The scaphoid is the most commonly fractured carpal bone.
2
Evaluate the radiographic findings in the context of the clinical presentation.
Initial radiographs are completely normal.
Up to 20% of acute scaphoid fractures are radiographically occult (invisible) at the time of injury. A nondisplaced hairline fracture may not appear until 7 to 14 days later when bone resorption widens the fracture line.
3
Determine the safest management strategy based on the suspected diagnosis.
Empiric immobilization with a thumb spica splint and outpatient follow-up for repeat imaging is required.
The scaphoid relies on a tenuous retrograde blood supply from the radial artery. Failing to immobilize an occult fracture significantly increases the risk of displacement, nonunion, and avascular necrosis of the proximal pole.

Key Concept

Management of radiographically occult scaphoid fractures
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Topics

Orthopedic Surgery

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