What are the indications for scaphoid views and clenched fist X-ray for the left wrist?

From the Guidelines

Scaphoid views and clench fist X-rays are essential for evaluating the left wrist for potential scaphoid fractures and ligamentous injuries, and I strongly recommend obtaining these views to prevent missing up to 20% of scaphoid fractures that may not be visible on standard wrist X-rays. For suspected scaphoid fractures, I recommend obtaining four specific scaphoid views: posteroanterior (PA), lateral, semi-pronated oblique, and scaphoid view (with the wrist in ulnar deviation) 1. These specialized views are necessary because standard wrist X-rays may miss scaphoid fractures due to the bone's unique curved shape and orientation.

Key Points to Consider

• The clench fist view should be performed with the patient actively making a tight fist during imaging, which stresses the scapholunate ligament and can reveal dynamic instability not visible on standard views 1.
• This technique helps identify scapholunate dissociation, where the gap between scaphoid and lunate bones widens abnormally (>3mm) during the clenched position.
• Scaphoid fractures can lead to avascular necrosis if missed, as the bone has a tenuous blood supply entering distally while most fractures occur proximally.
• If X-rays are negative but clinical suspicion remains high, follow-up imaging with MRI or CT scan may be necessary, as early detection and treatment significantly improves outcomes for these potentially serious wrist injuries 1.

Imaging Recommendations

• Radiography is always indicated as the initial imaging for suspected acute hand and wrist trauma 1.
• For patients with suspected distal radius fractures, a 3-view examination of the wrist usually includes a posteroanterior (PA), a lateral, and a 45 semipronated oblique view 1.
• In patients with suspected finger tendon injuries, radiographs are used to detect fracture fragments, as large fragments may require open reduction and internal fixation 1.

From the Research

Scaphoid Views and Clench Fist X-ray for Left Wrist

• The diagnosis of scaphoid fractures can be challenging, with up to 16% of fractures missed on initial plain radiographs 2.
• Advanced imaging modalities such as MRI, CT, and ultrasound can be used to diagnose scaphoid fractures, with MRI having the highest sensitivity and specificity 2.
• CT scans reformatted along the long axis of the scaphoid have been shown to have better diagnostic performance characteristics than CT scans in the planes of the wrist 3.
• The use of MRI direct from the emergency department can enable prompt diagnosis and early discharge of patients with normal radiographs following wrist trauma 4.
• In cases of clinically suspected scaphoid fracture, staged diagnostics including radiographs, CT, and MRI should be applied to confirm or exclude a fracture 5.

Imaging Modalities for Scaphoid Fractures

• MRI: high sensitivity and specificity for diagnosing scaphoid fractures, with values of 94.2% and 97.7%, respectively 2.
• CT: sensitivity and specificity of 81.5% and 96.0%, respectively 2.
• Ultrasound: sensitivity and specificity of 81.5% and 77.4%, respectively 2.
• Bone scintigraphy: significant differences in sensitivity and specificity compared to MRI, CT, and ultrasound 2.

Clinical Relevance

• Delayed or misdiagnosis of scaphoid fractures can have significant consequences, including nonunion, malunion, or avascular necrosis 6.
• Prompt diagnosis and treatment of scaphoid fractures are crucial to prevent late complications 5.
• The use of advanced imaging modalities can help improve diagnostic accuracy and patient outcomes 2, 3, 4.