关键词: 掌指关节, 　三维重建, 　数字化技术, 　接触面积

Abstract:

Objective　To build the 3-dimensional(3D) model and measure the effective joint contact areas of the metacarpophalangeal joint (MPJ) during flexion.　Methods　Ten healthy volunteers whose hands had no previous trauma or other pathological diseases were examined. All volunteers were male and right-handed. Three-dimensional computed tomography (CT) scanning was performed at 30° intervals during passive flexion from 0° to 90° with use of a CT scanner. The images data were obtained from CT scanning and then imported into the image processing software Mimics 17.0 to build the 3D model. the effective joint contact areas and the width of the contact region of the four fingers were measured in the model. The software SPSS 22.0 was adopted for data analysis.　Results　In the process of 2-5 MPJ flexion, the contact areas involved in joint activities from the dorsal to palm side gradually increased. From 0° to 90° flextion, The estimated MCH contact areas for the index finger was from (32.92±2.47) mm2 to (80.05±2.51) mm2; the middle finger from (35.90±2.48) mm2 to (88.63±2.04) mm2, the ring finger from (31.51±1.07) mm2 to (74.84±1.88) mm2, and the little finger from (26.19±2.12) mm2 to (57.80±0.81) mm2，respectively. 　Conclusion　In the process of 2~5 MPJ flexion, the view from the coronal plane, only about 1/2 of the articular surface belongs to the effective joint contact surface at 0 ° position, and all surfaces belong to the effective joint contact surfaces at 90° position, showing a trapezoidal increase in the contact areas.

Key words: Metacarpophalangeal joint；　Three-dimensional reconstruction;　Digital technology; , Contact areas