Motion Analysis of the Trapeziometacarpal Joint Using Three-dimensional Computed Tomography

Area of Science:

• Orthopedics
• Anatomy
• Biomechanics

Background:

• Zancolli's theory proposed axial rotation of the first metacarpal bone on the trapezium, controlled by ligaments.
• This study investigates the motion of the first metacarpal bone on the trapezium using advanced imaging techniques.

Purpose of the Study:

• To describe the motion of the first metacarpal bone on the trapezium.
• To analyze the range of motion and joint surface contact in the trapeziometacarpal joint.

Main Methods:

• Utilized three-dimensional computed tomography (3D-CT) on 30 healthy volunteers.
• Measured range of motion for radial abduction, retroposition, adduction, palmar abduction, and opposition.
• Determined main joint surface contacts between the trapezium and first metacarpal bone.

Main Results:

• Quantified pronation, radial abduction, and palmar abduction ranges across different movements.
• Identified specific contact surface areas (dorsal, ulnar, radial, volar) correlating with each motion.
• Observed that contact surfaces varied significantly depending on the thumb's position.

Conclusions:

• The trapeziometacarpal joint exhibits significant range of motion: 44° (radial abduction/adduction), 48° (palmar abduction/adduction), and 57° (pronation/supination).
• The dynamic nature of contact surfaces between the trapezium and first metacarpal bone is crucial for enabling this wide range of motion.