A Validated, Automated, 3-Dimensional Method to Reliably Measure Tibial Torsion

Area of Science:

• Orthopedics
• Medical Imaging
• Biomechanical Engineering

Background:

• Tibial torsion, a twist in the tibia, is crucial for lower limb function.
• Abnormal tibial torsion is linked to various painful clinical syndromes.
• Existing measurement methods lack standardization, with reported normal values varying significantly.

Purpose of the Study:

• To develop and validate an automated computer method for calculating tibial torsion.
• To compare the reliability of the automated method against current clinical techniques.
• To assess differences in torsion measurements between imaging modalities and sexes.

Main Methods:

• A controlled laboratory study involving 56 cadaveric and patient tibiae (CT scans) and 12 tibiae (MRI and structured light scans).
• Three blinded assessors applied two current clinical methods and the newly defined automated method.
• Statistical analysis included intraclass correlation coefficients (ICC) and t-tests to compare measurements.

Main Results:

• The automated method demonstrated excellent reliability (ICC = 1).
• Current clinical methods showed good reliability (ICC = 0.78-0.81).
• No significant differences were found between torsion values obtained from CT, MRI, and structured light scans.

Conclusions:

• Automated software-based measurements provide consistent, efficient, valid, and accurate results.
• Manual measurements are limited by assessor variability and experience.
• The study recommends adopting this automated method for clinical practice to establish reference values.