Femoral Anteversion in the Hip: Comparison of Measurement by CT, MRI, and Physical Examination
Authors: Botser IB, Ozoude GC, Martin DE, Siddiqi AJ, Kuppuswami S, Domb BG
DOI: 10.1016/j.arthro.2011.10.021
Purpose
To assess how femoral anteversion measurements compare between CT and MRI, and their relationship with physical exam and radiographic findings.
Methods
129 hips were measured for femoral anteversion by CT, MRI, and clinical exams, with analysis of correlations and reliability.
Key Findings
- CT and MRI measurements correlated strongly but CT consistently showed about 9° higher anteversion.
- CT had better interobserver reliability than MRI.
- Internal hip rotation correlated better with CT anteversion.
- Low anteversion associated with cam impingement; high anteversion with pincer impingement.
Conclusion
CT is more reliable than MRI for measuring femoral anteversion and correlates better with clinical findings; the two imaging methods should not be used interchangeably.
What this means for providers
When evaluating femoral version in patients with hip pathology, CT provides more consistent and reliable anteversion measurements than MRI, with stronger correlation to physical exam findings such as internal rotation. Clinicians should be cautious about using CT and MRI interchangeably for surgical planning, especially when femoral version plays a key role in diagnosis and treatment of impingement syndromes.