From the Guidelines
A scaphoid hidden fracture requires immediate immobilization in a thumb spica cast or splint, even when initial X-rays appear normal but clinical suspicion exists. If you have wrist pain, tenderness in the anatomical snuffbox, or pain with axial compression of the thumb after a fall on an outstretched hand, you should be treated as having a potential scaphoid fracture despite negative X-rays. Advanced imaging with MRI or CT scan should be obtained within 1-2 weeks if symptoms persist, as these can detect fractures missed on plain radiographs 1.
Key Considerations
- The scaphoid has a tenuous blood supply, particularly to its proximal pole, putting it at high risk for avascular necrosis, non-union, and long-term wrist arthritis if fractures are missed or inadequately treated 2.
- Early detection and proper management are crucial to prevent these complications, which can lead to chronic pain and disability.
- Treatment typically involves 6-12 weeks of immobilization for non-displaced fractures, while displaced fractures often require surgical fixation.
Imaging Recommendations
- Either MRI without IV contrast or CT without IV contrast is usually appropriate for detecting radiographically occult fractures or stress fractures 1.
- IV contrast does not add to the examination and is usually not appropriate 1.
- MRI is highly sensitive to changes in bone marrow composition and can be used to identify radiographically occult acute fractures throughout the skeleton, including in the wrist 1.
Clinical Approach
- Clinical suspicion of a scaphoid fracture should be based on a history of trauma and focal pain on palpation, and confirmed with radiographic studies or advanced imaging if necessary 3.
- Immobilization and prompt evaluation with advanced imaging are critical to prevent long-term complications and ensure optimal outcomes.
From the Research
Diagnosis of Scaphoid Hidden Fracture
- Scaphoid fractures are among the most common fractures of the bones of the wrist and usually result from a forceful extension of the wrist 4.
- If the diagnosis cannot be established by clinical and radiographic examination, advanced imaging modalities such as MRI, CT, bone scintigraphy, or ultrasound are recommended 4, 5, 6, 7.
- MRI has been shown to have the highest sensitivity and specificity for diagnosing scaphoid fractures, with a sensitivity of 94.2% and specificity of 97.7% 5.
- CT scan also has high sensitivity and specificity, with values of 81.5% and 96.0%, respectively 5.
- Ultrasound has been found to have a sensitivity of 78% and specificity of 89% in diagnosing scaphoid fractures 7.
- Bone scintigraphy has been shown to be accurate in diagnosing occult scaphoid fractures, but may over-diagnose in some cases 6.
Imaging Modalities for Scaphoid Fracture Diagnosis
- MRI is the imaging modality of choice for depiction of radiographically occult scaphoid fracture, bone contusion, and associated soft tissue injury 8.
- CT is useful for visualization and characterization of the fracture line, and the amount of displacement and angulation of the fracture fragments 8.
- Ultrasound can be used to investigate occult suspected scaphoid fractures, allowing for early diagnosis and eliminating the need for more invasive or expensive diagnostic tests in most cases 7.
- Bone scintigraphy can be used to diagnose occult scaphoid fractures, but its accuracy may be limited by over-diagnosis in some cases 6.
Treatment of Scaphoid Fractures
- Nonsurgical treatment with cast immobilization is recommended for stable fractures, while open reduction and screw fixation is recommended for unstable fractures 4.
- Percutaneous screw fixation can be considered as an alternative to treatment with a thumb spica cast for nondisplaced or minimally displaced scaphoid fractures 4.
- Early mobilization of stable fractures after internal fixation and the possible use of a playing splint after athletic injuries when secure internal fixation is achieved are also recommended 4.