Analysis on anatomy and biomechanics of ligaments in carpometacarpal joints of the thumb and its clinical significance / 医用生物力学

ABSTRACT

Objective To study the anatomic and biomechanical characteristics of the dorsal radial ligament and anterior oblique ligament in carpometacarpal (CPC) joints of the thumb,so as to provide references for ligament repair.Methods Forty fresh hand specimens of adult male cadavers were dissected to make specimen of trapezium bone-ligament-the first metacarpal bone,of which 20 cases retained the dorsal radial ligament and 20 cases retained the anterior oblique ligament,respectively.The ligaments were tested on biomechanical testing machine,and their length,width,thickness,the maximum load,elastic modulus and elongation rate were measured and calculated.Results For the dorsal radial ligament and anterior oblique ligament,their maximum load was (213.5 ±72.4) and (168.7 ±35.2) N,their elastic modulus was (17.2 ±6.7) and (9.3 ±2.5) MPa,their elongation rate was (116.2 ± 21.3) ％ and (92.7 ± 22.4) ％,respectively.The maximum load,elastic modulus and elongation of the dorsal radial ligament were larger than those of the anterior oblique ligament.Conclusions For the capsular ligament in CPC joints of the thumb,the dorsal radial ligament has a higher stiffness and stronger toughness,which plays an important role in maintaining stability of the joint.The anterior obligue ligament is easy to be damaged due to its smaller stiffness and poor toughness.The anterior oblique ligament is suggested to be reconstructed firstly to treat arthritis of CMC joints,and materials whose elastic modulus and elongation rate are similar with the dorsal radial ligament should be selected.