关键词: 掌指关节, 　生物力学, 　有限元分析, 　应力 

Abstract: Objective　To establish a three-dimensional finite element model of the metacarpophalangeal joint (MPJ), and analyze the stress distribution of the MPJ surface in the flexion and extension of the MPJ.　Methods　The hands of one healthy volunteer were examined. Three-dimensional CT scanning was performed at 30° intervals during passive flexion from 0° to 90° with use of a CT scanner. The CT scan data were used to establish the three-dimensional finite element model of the MPJ. The load distribution of the MPJ was observed by applying 10, 20, 30, 40 and 50 N loading along the radial direction of the phalanx at four angles, and the results were analyzed.　Results　The number of nodes and the number of units of the four sets of MPJ mesh models with different bending angles were basically the same. Each group of models has about a total of 40070 nodes and 178903 tetrahedral units. Under the same load, the greater the angle of bending, the greater the stress on the MPJ surface. During the angles of 0°, 30°, 60° and 90°, the peak stress range of the metacarpal head of 2~5 MPJs was respectively, 0.20~2.46, 0.22~1.58, 0.22~1.69, 0.22~2.25 MPa.　Conclusion　During the flexion and extension of the MPJ, the greater the angle of bending, the greater the contact stress of the MPJ surface, and the wider the range of stress distribution.

Key words: Metacarpophalangeal joint, 　 Biomechanics, 　 Finite element analysis, 　 Stress