Optimizing Volar Tilt Restoration and Plate Position in Distal Radius Fractures.

Area of Science:

• Orthopedic surgery
• Biomechanics
• Hand surgery

Background:

• Distal radius fractures are common orthopedic injuries.
• Surgical fixation often involves volar plating.
• Flexor pollicis longus (FPL) tendon complications like tendonitis or rupture can occur after volar plating.

Purpose of the Study:

• To investigate the hypothesis that failure to restore distal radius volar tilt increases pressure on the FPL tendon.
• To evaluate the effect of plate placement relative to the watershed line on FPL tendon pressure.

Main Methods:

• Ten fresh-frozen cadaveric wrists were used.
• Reproducible distal radius fractures were created and fixed with volar plates.
• FPL tendon contact forces were measured under various surgical conditions, including restored and unrestored volar tilt and different plate positions.

Main Results:

• Failure to restore volar tilt significantly increased FPL tendon contact forces (mean increases of 1.9 N and 3.0 N).
• Plate placement distal to the watershed line also significantly increased FPL tendon contact forces (mean increase of 2.03 N) compared to restoring volar tilt.
• Dorsal plating without restoring volar tilt resulted in higher FPL tendon pressures compared to plate placement distal to the watershed line.

Conclusions:

• Failure to restore volar tilt during surgical treatment of distal radius fractures elevates FPL tendon pressure.
• Volar plate placement distal to the watershed line increases FPL tendon pressure over the plate edge.