What is the sensitivity of X-ray (X-radiation) for detecting scaphoid fractures?

Sensitivity of X-ray for Scaphoid Fracture Detection

X-ray has very low sensitivity for detecting scaphoid fractures, with initial radiographs demonstrating only 15-35% sensitivity. 1

Initial Radiographic Evaluation

• Standard radiographs are the recommended first-line imaging modality for suspected scaphoid fractures despite their low sensitivity 1
• Initial conventional radiographs have a sensitivity of only 15-35% for detecting scaphoid fractures, meaning they miss approximately 65-85% of fractures 1
• Even with dedicated "scaphoid views," many fractures remain radiographically occult on initial imaging 2
• Follow-up radiographs taken 10-14 days after injury show improved but still suboptimal sensitivity of 30-70% 1

Factors Affecting X-ray Sensitivity

• Early radiographic findings of scaphoid fractures are often nonspecific (subtle periosteal reaction, gray cortex sign) or completely absent 1
• Detection of osseous changes is more limited in areas with prominent overlapping soft tissue, such as the wrist 1
• The sensitivity of radiographs varies depending on:
  • Timing of imaging relative to injury 1
  • Patient's metabolic bone status 1
  • Type and location of the fracture 1
  • Quality of positioning and technique 2

Comparison with Advanced Imaging Modalities

• MRI without contrast demonstrates significantly higher sensitivity (94.2%) and specificity (97.7%) for scaphoid fractures compared to X-ray 2, 3
• CT scan shows better sensitivity (81.5%) and specificity (96.0%) than X-ray but remains less sensitive than MRI 3
• Bone scintigraphy has high sensitivity but lower specificity compared to MRI and CT 2
• Ultrasound demonstrates moderate sensitivity (81.5%) and specificity (77.4%) but is not recommended as a primary diagnostic tool for scaphoid fractures 2, 3

Clinical Implications

• Due to the poor sensitivity of initial radiographs, clinical suspicion should guide further management when X-rays are negative 2, 4
• Follow-up radiography has poor reliability as a diagnostic examination for detecting scaphoid fractures in patients with normal initial radiographs (inter-observer reliability coefficient of only 33%) 5
• When initial radiographs are negative but clinical suspicion remains high, proceeding directly to MRI rather than presumptive casting and repeat radiographs is recommended 2
• Using clinical decision rules like the Clinical Scaphoid Score can help identify patients who need advanced imaging despite normal X-rays 4

Common Pitfalls

• Relying solely on initial negative radiographs can lead to missed scaphoid fractures in up to 16% of cases 3
• Follow-up radiographs alone are not reliable enough to rule out scaphoid fractures (negative predictive values of only 30-40%) 5
• Failure to obtain adequate radiographic views, including dedicated scaphoid views, may further decrease sensitivity 2, 6
• Delaying appropriate treatment due to false-negative X-rays can lead to complications including nonunion, malunion, and avascular necrosis 1