The normal ischiofemoral distance and its variations

Area of Science:

• Orthopaedic anatomy
• Radiology
• Biomechanical studies

Background:

• The ischiofemoral distance (IFD) is a key anatomical measurement of the hip.
• Understanding IFD variations is essential for diagnosing hip pathologies and guiding surgical interventions.
• Previous studies have not comprehensively analyzed IFD variations across gender, age, and proximal femoral anatomy.

Purpose of the Study:

• To measure the ischiofemoral distance (IFD) in a healthy hip population.
• To investigate the influence of gender, age, and proximal femoral anatomy on IFD.
• To establish reference values for IFD for future research and clinical applications.

Main Methods:

• Retrospective analysis of 149 patient CT scans (298 hips) acquired for non-orthopaedic reasons.
• Independent measurement of IFD, offset, and neck-shaft angle by two observers.
• Statistical analysis to determine correlations between IFD and demographic/anatomical factors.

Main Results:

• Mean IFD was significantly greater in males (23 ± 7 mm) than females (18.6 ± 8 mm) (P < 0.001).
• IFD increased with femoral offset (1.06 mm/mm) and decreased with age (0.09 mm/year).
• No significant correlation was found between neck-shaft angle and IFD.

Conclusions:

• Gender, age, and femoral offset are significant determinants of ischiofemoral distance.
• This study provides valuable normative data for IFD, aiding in the interpretation of hip imaging and biomechanical assessments.
• The findings underscore the importance of considering individual anatomical variations in clinical practice and research.