Quantification of radial torsion angle with computerized tomography: a clinical study

Area of Science:

• Orthopedics
• Radiology
• Biomechanics

Background:

• Distal radial fractures are common injuries.
• Assessing long-term functional outcomes after these fractures is crucial.
• Previous studies have not fully explored rotational deformities.

Purpose of the Study:

• To evaluate the clinical utility of the radial torsion angle (RTA) in patients with prior distal radial fractures.
• To compare RTA in patients with distal radial fractures to normal controls.
• To investigate the correlation between RTA and forearm range of motion (ROM).

Main Methods:

• Bilateral upper extremity CT scans were performed on 19 patients with distal radial fractures and 5 normal controls.
• Radial torsion angle (RTA) and side-to-side RTA difference were calculated by two radiologists.
• Correlation analysis was conducted between RTA and forearm ROM.

Main Results:

• Patients with previous distal radial fractures showed a significantly increased mean side-to-side RTA difference (18.4 ± 10 degrees) compared to normal subjects (3.0 ± 1.41 degrees).
• A statistically significant difference in RTA was observed between the affected and unaffected sides in patients (49.3 ± 22.4 vs. 36.7 ± 13.8 degrees).
• Good inter-rater agreement (Kappa = 0.62) was found for side-to-side RTA difference measurements.

Conclusions:

• The side-to-side difference in radial torsion angle is significantly elevated in individuals with a history of distal radial fractures.
• RTA measurement, particularly the side-to-side difference, appears to be a valuable tool for assessing rotational deformities post-fracture.
• Further research is warranted to explore the clinical implications of altered RTA on forearm function and long-term outcomes.