Interosseous Ligament and Transverse Forearm Stability: A Biomechanical Cadaver Study

Area of Science:

• Orthopedics
• Radiology
• Biomechanics

Background:

• The interosseous ligament (IOL) is a key longitudinal stabilizer of the forearm.
• Its role in transverse stability and contribution to pronosupination tensioning is less understood.

Purpose of the Study:

• To investigate the hypothesis that the IOL contributes to transverse forearm stability.
• To determine if IOL injury leads to a measurable widening of the interosseous space on radiographs.

Main Methods:

• Ten cadaver forearms were radiographed in various positions, both intact and after IOL sectioning (partial and complete).
• Transverse interosseous distance was measured using edge detection software.
• Pronosupination range of motion was compared before and after IOL sectioning.

Main Results:

• Complete IOL sectioning significantly increased the interosseous distance by at least 2 mm in most positions.
• Maximum supination increased from 84° to 106°, and pronation from 69° to 84° after complete IOL sectioning.

Conclusions:

• The IOL is crucial for transverse stability of the forearm radius and ulna.
• IOL injury results in increased pronosupination and a wider interosseous space.
• Comparative radiography of bilateral forearms can reliably diagnose IOL tears.