2~5掌指关节有效关节接触面的数字化研究

目的　建立2~5掌指关节屈伸活动中有效关节接触面的三维模型及测量有效接触面积的大小。 方法　选择身体健康的青年男性、手部既往无外伤及其他病理性疾病病史的志愿者10例。 将志愿者右手2~5掌指关节分别固定在0°、30°、60°、90°位，利用CT分别进行扫描获得图像数据，数据导入Mimics17.0进行2~5掌指关节模型的三维重建及有效关节接触面的标记，测量掌骨长度及有效接触面积，应用SPSS软件进行数据分析。 结果　在0°至90°屈曲过程中，掌骨头上参与关节活动的有效接触面积从背侧至掌侧逐渐增大，其中示指有效接触面积在0°~90°时为(32.92±2.47)~(80.05±2.51) mm2；中指为 (35.90±2.48) ~(88.63±2.04) mm2；环指为(31.51±1.07) ~ (74.84±1.88)mm2；小指为(26.19±2.12) ~(57.80±0.81) mm2。 结论　2~5掌指关节屈曲过程中，从冠状面看，0°位时仅有中间约1/2的关节面属于有效关节接触面，而90°位时则100%均属于有效关节接触面，呈梯形增加。

The digital study of evaluating contact areas of the 2~5 metacarpophalangeal joint

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.