MORPHOMETRIC AND BIOMECHANICAL COMPARISON OF TENDONS USED FOR INTERPOSITION ARTHROPLASTY IN CARPOMETACARPAL ARTHRITIS OF THE THUMB

Abstract

Purpose: To identify the wrist tendon most effectively maintaining the trapezial space in interpositional arthroplasty in osteoarthritis of the carpometacarpal joint of the thumb.Methods: The morphometrics of the os trapezium and the tendons of the flexor carpi radialis, extensor carpi radialis longus, and abductor pollicis longus were determined. The stiffness and compressive loading characteristics of the rolled-up tendons were compared to the os trapezium.Results: No significant morphometric differences between the three tendons were found. The mass and volume of the trapezium was significantly larger when compared to the tendon balls. No significant differences in the compressive loading resistance were found between the tendons, but the mean stiffness was 85% lower when compared to the os trapezium.Conclusions: Neither tendon material approached the volume nor the stiffness provided by the os trapezium. Any tendon is considered to insufficiently maintain the trapezial space following trapeziectomy.