X-ray Views for Left Thumb Deep Cut Injury
For a left thumb deep cut injury, posteroanterior (PA), lateral, and oblique (45° semipronated) views should be ordered as the initial radiographic evaluation to assess for fractures, foreign bodies, and joint alignment. 1, 2
Initial Radiographic Assessment
The American College of Radiology recommends the following essential views for thumb trauma:
- Posteroanterior (PA) view: Evaluates bone alignment and joint spaces
- Lateral view: Assesses displacement and angulation
- Oblique view (45° semipronated): Increases diagnostic yield for fractures and displacements 2
These three views provide comprehensive assessment of the thumb's bony structures and should be obtained with proper positioning to avoid diagnostic errors.
Rationale for Proper Radiographic Technique
Poor radiographic technique can lead to missed or misdiagnosed fractures. Key considerations include:
- Ensure true lateral radiographic views of the fingers and true anteroanterior views of the thumb, as inadequate views are the most frequent reason for diagnostic errors 3
- Avoid superimposition of fingers on lateral radiographs, which can lead to misjudgment of fracture displacement 3
- Never accept poor quality radiographs or inadequate views as a basis for treatment 3
Additional Imaging Considerations
If initial radiographs are negative but clinical suspicion remains high:
- CT scanning: Consider if there is concern for complex fractures with intra-articular extension or for preoperative planning 1, 2
- MRI without contrast: Recommended when there is high clinical suspicion despite normal radiographs, especially useful for detecting concomitant ligamentous lesions 2
- Ultrasound: May be useful for detecting superficial foreign bodies, including radiolucent materials, with high sensitivity 2
Special Considerations for Thumb Injuries
- For suspected ulnar collateral ligament injury (skier's thumb), stress testing is mandatory even when bony avulsion fracture with minimal displacement is suspected, as the fracture may not be a true bony avulsion but rather fragmentation associated with complete ligament disruption 4
- The thumb should be preserved at all costs in cases of severe injury, as it is critical for hand function 5
Potential Pitfalls to Avoid
- Failure to obtain proper views can lead to missed fractures
- Superficial assessment on standard PA and lateral radiographs may result in incomplete recognition of the injury pattern 6
- Accepting inadequate radiographs can lead to misdirected treatment approaches 3
- Overlooking subtle radiographic findings may result in accepting reductions with significant residual incongruency 6
By following these guidelines for radiographic assessment of a left thumb deep cut injury, you can ensure proper evaluation and guide appropriate treatment decisions.