Interobserver reliability of radial head fracture classification: two-dimensional compared with three-dimensional CT.

Area of Science:

• Orthopaedic Surgery
• Radiology
• Medical Imaging

Background:

• The Broberg and Morrey modification of the Mason classification for radial head fractures exhibits significant interobserver variability.
• This variability complicates accurate fracture assessment and treatment planning.

Purpose of the Study:

• To evaluate if three-dimensional (3D) CT reconstructions enhance interobserver reliability in classifying radial head fractures using the Broberg and Morrey system.
• To compare the reliability of 3D CT versus 2D CT in assessing fracture characteristics and guiding treatment.

Main Methods:

• Eighty-five orthopaedic surgeons assessed 12 radial head fractures.
• Surgeons were randomized to review either radiographs with 2D CT or radiographs with 3D CT images.
• Interobserver agreement was measured using the kappa multirater measure (κ).

Main Results:

• 3D CT demonstrated moderate agreement, while 2D CT showed fair agreement for the Broberg and Morrey classification (p < 0.05).
• Significant differences in agreement between 3D and 2D CT were found for identifying small fragments, recognizing >3 fragments, and central impaction.
• Agreement on treatment recommendations was fair for both 3D and 2D CT.

Conclusions:

• 3D CT scans offer a statistically significant, albeit small, improvement in reducing interobserver variation for radial head fracture classification.
• Considerable disagreement remains among surgeons regarding classification and characterization, suggesting 3D CT alone may be insufficient for optimal reliability.