Elimination of the Femoral Neck in Measuring Femoral Version Allows for Less Variance in Interobserver Reliability

Area of Science:

• Orthopedics
• Radiology
• Biomechanical Engineering

Background:

• Consistent measurement of femoral version is essential for evaluating and planning corrective surgical procedures.
• Computed tomography (CT) is a key imaging modality for assessing bone morphology and alignment.

Purpose of the Study:

• To compare the interobserver reliability of two CT-based techniques for measuring femoral version.
• To determine if a novel CT method offers improved reliability for femoral version assessment.

Main Methods:

• Retrospective review of CT scanograms from 15 patients with comminuted femoral shaft fractures (Winquist III and IV).
• Five observers measured femoral version using two distinct CT-based techniques.
• Technique 1: Proximal measurement via the femoral head-neck center. Technique 2: Measurement via the femoral head center and the shaft at the lesser trochanter.

Main Results:

• The proximal technique yielded a mean femoral version of 9.50° ± 4.82°, with an intraclass correlation coefficient (ICC) of 0.960.
• The lesser trochanter technique resulted in a mean femoral version of 18.73° ± 2.69°, with a near-perfect ICC of 0.993.
• A significant difference (p ≤ 0.001) was observed between the two measurement methods, with a ~10° discrepancy.

Conclusions:

• The CT technique measuring femoral version at the lesser trochanter demonstrates excellent interobserver reliability.
• This novel technique provides a reliable method for assessing femoral version, differing significantly from proximal measurement approaches.
• Both CT techniques exhibit high interobserver reliability, but the lesser trochanter method offers a more precise and reproducible measurement.