Defining reference values for the normal tibiofibular syndesmosis in adults using weight-bearing CT

Area of Science:

• Orthopedic imaging
• Radiology
• Biomechanics

Background:

• Weight-bearing cone beam CT (CBCT) offers cross-sectional imaging of the tibiofibular syndesmosis.
• Accurate assessment of syndesmotic injuries and reconstruction requires established normal measurement ranges.
• Understanding normal syndesmotic anatomy in weight-bearing conditions is crucial for clinical evaluation.

Purpose of the Study:

• To establish normal reference measurements for the tibiofibular syndesmosis using weight-bearing CBCT.
• To investigate potential side-to-side variations in syndesmotic anatomy.
• To determine the influence of age and gender on syndesmotic measurements.

Main Methods:

• Retrospective analysis of 200 feet (50 males, 50 females) aged 18+ years.
• Bilateral, simultaneous weight-bearing CBCT imaging using the pedCAT machine.
• Measurement of six lengths, one angle, and calculation of three additional parameters to assess tibiofibular relationships.

Main Results:

• The upper limit for normal lateral translation was 5.27 mm; higher values may indicate injury.
• No significant differences were observed between right and left legs.
• Increasing age correlated with reduced lateral translation, and males exhibited greater lateral translation.

Conclusions:

• Normal reference ranges for weight-bearing tibiofibular syndesmosis anatomy have been established.
• Syndesmotic anatomy is unaffected by side (left vs. right) in uninjured individuals.
• Age and gender are significant factors influencing syndesmotic anatomy and must be considered during assessment.