正常成人胫骨近端骨骺融合部位的形态学分析

Morphological analysis of proximal tibial epiphyseal fusion site in normal adults

目的利用Mimics三维重建技术研究正常成人胫骨近端骨骺融合部位的形态学特征并分析其潜在的临床价值。方法回顾性分析2020年6月至2021年6月收集下肢无明显异常者膝关节CT影像学资料,其中男41例、女27例,年龄为(38.7±8.4)岁(范围25~55岁),体质指数(body mass index,BMI)为(25.3±4.0)kg/m^(2)(范围18.75~41.8 kg/m^(2))。利用Mimics三维重建技术重建胫骨近端和骨骺融合部位的三维模型。研究骨骺融合部位的表面积与年龄、BMI的关系,同时分析骨骺融合部位骨皮质厚度和骨密度的变化情况。结果利用Mimics三维重建技术重建出的成人骨骺融合部位在三维空间上是一个复杂的波浪起伏的板状结构。通过3-Matic Research 12.0软件获得骨骺融合部位的表面积为(2994.7±645.3)mm^(2)(范围1704.0~4650.0 mm^(2))。男性骨骺融合部位表面积为(3269.3±533.9)mm^(2),大于女性的(2577.6±578.7)mm^(2),差异有统计学意义(t=5.06,P<0.001)。骨骺融合部位表面积与年龄(R2=0.02,P=0.268)和BMI(R2=0.04,P=0.125)无显著相关性。利用Mimics软件在膝关节CT的横断面获取骨骺线部位、骨骺线远端10 mm及20 mm层面骨皮质CT值分别为(451.059±74.953)Hu、(1018.412±125.732)Hu、(1414.162±107.848)Hu。测量骨骺线部位、骨骺线远端10 mm及20 mm层面骨皮质厚度分别为(1.814±0.090)mm、(2.511±0.089)mm及(3.189±0.185)mm。结论采用Mimics三维重建技术可对正常成人胫骨近端骨骺融合部位进行可视化研究。成人骨骺融合部位为波浪起伏的板状结构,骨骺融合部位的骨皮质密度较低、厚度较薄,理论上讲在间接暴力下容易发生骨折。

Objective To study the morphologic features of the fusion site of proximal tibial epiphysis in normal adults and analyze its potential clinical value based on Mimics three-dimensional(3D)reconstruction.Methods CT images of knee joint of 68 patients without obvious abnormalities of lower limbs were retrospectively analyzed in electronic database of our hospital from June 2020 to June 2021,including 41 males and 27 females.The mean age of the patients was 38.7±8.4 years(range,25-55 years),and the mean body mass index(BMI)was 25.3±4.0 kg/m^(2)(range,18.75-41.8 kg/m^(2)).Mimics 3D reconstruction technique was used to reconstruct the 3D model of the proximal tibia and epiphyseal fusion site.The relationship between the surface area of epiphyseal fusion site and age and BMI was studied,and the changes of cortical thickness and density at epiphyseal fusion site were also explored.Results The fusion site of adult epiphyseal reconstructed by Mimics 3D reconstruction is a complex wavy surface structure in 3D space.The surface area of the epiphyseal fusion site was 2,994.7±645.3 mm^(2)(range,1,704.0-4,650.0 mm^(2))obtained by 3-Matic Research 12.0.The fusing area of male epiphysis was 3269.3±533.9 mm^(2) than that of female 2,577.6±578.7 mm^(2),the difference was statistically significant(t=5.06,P<0.001).However,there was no significant correlation between the epiphyseal fusion site surface area and age(R2=0.02,P=0.268)and BMI(R2=0.04,P=0.125).Mimics software was used to obtain the CT values of bone cortex at the epiphysis line and the distal end of the epiphysis line at 10 mm and 20 mm levels as 451.059±74.953 Hu,1,018.412±125.732 Hu and 1,414.162±107.848 Hu,respectively.The thickness of bone cortex was 1.814±0.090 mm,2.511±0.089 mm and 3.189±0.185 mm at 10 mm and 20 mm layers of epiphysis line and distal epiphysis line,respectively.Conclusion In this study,Mimics 3D reconstruction technique was used to visualize the fusion site of the proximal tibial epiphysis in normal adults.The epiphyseal fusion site of adult is a undulating plate-like structure,and the cortical bone density of epiphyseal fusion site is low and thin,theoretically,it is easy to fracture under indirect violence.