Angle measurements of the distal radius: a cadaver study

Area of Science:

• Orthopedics
• Radiology
• Biomechanics

Background:

• Distal radius fracture reduction quality is typically assessed using radial angle and palmar tilt.
• Forearm rotation can introduce variability in radiographic measurements.

Purpose of the Study:

• To investigate the effect of forearm rotation on palmar tilt and radial angle measurements.
• To evaluate interobserver variability in assessing these parameters.
• To recommend optimal radiographic views for accurate fracture assessment.

Main Methods:

• Cadaveric study analyzing distal radius fractures.
• Radiographic measurements of palmar tilt and radial angle were taken.
• Variations in forearm rotation were introduced to assess measurement changes.
• Interobserver variability among surgeons was quantified.

Main Results:

• A 5-degree forearm rotation caused a 1.6-degree change in palmar tilt on the conventional lateral view and a 1.0-degree change on the 15-degree lateral view.
• Rotation can lead to measurement errors of up to 6.4 degrees.
• Interobserver variability was lower for the 15-degree lateral view (2.1 degrees) compared to the conventional lateral view (3.6 degrees) for palmar tilt.

Conclusions:

• Forearm rotation significantly affects palmar tilt measurements in distal radius fractures.
• The 15-degree lateral view is recommended for routine use, especially in fractures with dorsal angulation, to improve accuracy and reduce measurement error.
• Standardizing radiographic techniques can minimize interobserver variability in fracture assessment.