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Difficulty: MediumOrthopedic Surgery

A 24-year-old man presents to the urgent care clinic with right wrist pain. Two days ago, he fell forward onto his outstretched right hand while playing basketball. He notes focal swelling and pain that worsens when gripping objects. Vital signs are temperature 36.8°C (98.2°F), blood pressure 118/76 mm Hg, heart rate 72/min, and respiratory rate 14/min. Physical examination reveals localized tenderness over the dorsal radial aspect of the right wrist, specifically in the depression bounded by the extensor pollicis longus and extensor pollicis brevis tendons. Pain is reproduced with axial compression of the first metacarpal. Neurovascular assessment shows 2+ radial and ulnar pulses with brisk capillary refill and normal sensation to light touch in all digits. Initial anteroposterior, lateral, and scaphoid-view radiographs of the right wrist demonstrate no fracture lines, step-offs, or dislocations. Which of the following is the most appropriate next step in management?

  1. A
    Application of a short-arm volar splint allowing free movement of the thumb
  2. B
    Immediate open reduction and internal fixation of the scaphoid bone
  3. Immobilization in a thumb spica splint and repeat radiographs in 10 to 14 daysAnswer
  4. D
    Reassurance, administration of NSAIDs, and application of a simple elastic compression bandage
  5. E
    Diagnostic aspiration of the radiocarpal joint and empiric intravenous antibiotics

Answer

Immobilization in a thumb spica splint and repeat radiographs in 10 to 14 days
The patient's mechanism of injury (fall on an outstretched hand) and physical examination findings (tenderness in the anatomical snuffbox and pain with axial loading of the first metacarpal) are highly characteristic of a scaphoid fracture. Due to the scaphoid's retrograde arterial blood supply, fractures across its waist place the proximal pole at severe risk for nonunion and avascular necrosis if not strictly immobilized. Because up to 20% of scaphoid fractures are radiographically occult during the first week, a negative initial radiograph does not rule out the injury. The standard of care is to empirically treat the patient for a non-displaced scaphoid fracture. This requires immobilization in a thumb spica splint—which prevents movement of both the wrist and the thumb—and scheduling repeat radiographs in 10 to 14 days. By that time, osteoclastic resorption at the fracture site will widen the radiolucency, making the fracture visible on imaging.

Step-by-Step Solution

1
Identify the mechanism of injury and physical exam findings.
The patient experienced a fall on an outstretched hand (FOOSH) and presents with anatomical snuffbox tenderness and pain on axial loading of the thumb.
These findings are highly sensitive and classic clinical indicators for a scaphoid fracture, even in the absence of obvious deformity.
2
Evaluate the initial imaging results.
Initial radiographs are entirely normal with no visible fracture lines.
Up to 20% of scaphoid fractures are radiographically occult at the time of initial injury because the fracture line is microscopic before osteoclastic resorption occurs.
3
Determine the safest management strategy based on the suspected pathology.
Empiric immobilization with a thumb spica splint and outpatient follow-up for repeat imaging in 10-14 days.
The scaphoid bone relies on a tenuous, retrograde blood supply. Missing an occult fracture and allowing free movement significantly increases the risk of avascular necrosis and nonunion of the proximal pole.

Key Concept

Patients with a clinical presentation highly suspicious for a scaphoid fracture (anatomical snuffbox tenderness after a FOOSH injury) but negative initial radiographs must be presumed to have an occult fracture and treated with a thumb spica splint and repeat imaging in 1-2 weeks.

Alternative Method

An acceptable alternative to empirical splinting and delayed radiographs is to obtain an immediate MRI of the wrist, which can definitively diagnose or rule out an occult scaphoid fracture on the day of presentation. This is often utilized in high-performance athletes to avoid unnecessary immobilization.
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Orthopedic Surgery

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