Comprehensive simulation on morphological and mechanical properties of trigger finger - A cadaveric model

Area of Science:

• Orthopedics
• Biomechanics
• Hand Surgery

Background:

• Trigger finger is a common hand disorder with controversial etiology.
• Previous studies on trigger finger biomechanics often used normal fingers.
• Understanding causative factors requires advanced models simulating pathological conditions.

Purpose of the Study:

• To develop a feasible human cadaver model of trigger finger.
• To simulate trigger finger by creating tendon nodules and pulley constriction.
• To investigate the biomechanical changes associated with a simulated trigger finger.

Main Methods:

• A trigger finger model was created in human cadavers using silicone gel injection for tendon nodules and external compression for pulley constriction.
• Indentation and gliding resistance tests were performed on the modified cadaveric specimens.
• Mechanical properties, including tendon thickness and gliding resistance, were measured and compared.

Main Results:

• Silicone gel injection significantly increased tendon thickness.
• No significant change in the tendon's compressive modulus was observed post-injection.
• Gliding resistance and work of extension increased significantly with the severity of the simulated triggering.

Conclusions:

• A feasible human cadaver model for trigger finger, incorporating both nodule formation and pulley constriction, was successfully developed.
• This model can be used for further research into the biomechanical features and causative factors of trigger finger.
• The model validates the link between increased gliding resistance and trigger finger severity.