基于成人膝关节骨软骨复合体微结构特征参数设计仿生骨软骨支架的实验研究

Experimental study on design of biomimetic osteochondral scaffold based on microstructure characteristic parameters of adult knee joint osteochondral complex

目的探讨正常成人骨软骨复合体的微结构特征,提供一种新型仿生骨软骨支架模型的设计方案。方法随机选取3具非骨组织疾病致死的成年人尸体,在左右膝关节股骨关节面的外侧髁、内侧髁、髌面各取一大小相同的正方体骨块。利用高分辨率显微CT断层扫描系统对标本进行扫描,获取软骨、软骨下骨板平均厚度,松质骨骨小梁及其松质骨间隙的形态计量学参数BV/TV、TbN、TbTh、TbSp,并进行对比分析。依据获得的解剖数据,采用计算机辅助软件VG Studio MAX 3.4构建具有特定内部结构的骨软骨支架模型。结果髌面软骨平均厚度大于外侧髁、内侧髁(P<0.05);髌面软骨下骨板平均厚度大于外侧髁、内侧髁(P<0.05);髌面软骨厚度/骨板厚度小于外侧髁、内侧髁(P<0.05);松质骨骨小梁形态计量学参数TbSp及松质骨间隙形态计量学参数TbTh在外侧髁与髌面之间差异有统计学意义(P<0.05)。利用计算机辅助软件VG Studio MAX 3.4构建的用于非可降解材料的数字化模型,具有与正常骨软骨复合体一致的三维结构;用于可降解材料的数字化模型,其软骨层及软骨下骨板层结构与正常软骨及软骨下骨板结构一致,其支架层的结构类似于正常骨小梁间隙的三维结构。结论人体膝关节不同部位的骨软骨复合体微结构特征存在一定的差异性,基于Micro-CT数据和计算机辅助设计可以精确构建骨软骨支架数字化三维模型。

Objective To explore the microstructure characteristics of normal adult osteochondral complexes,and provide a new design scheme for a new type of bionic osteochondral scaffold model.Methods Three adult cadavers of non-bone tissue diseases were randomly selected,and a cube of the same size was taken from the lateral condyle,medial condyle,and patellar surface of the femoral articular surface of left and right knee joints.The specimens were scanned with a high-resolution micro-CT tomography system to obtain and compare the average thickness of cartilage and subchondral bone plate,and the morphometric parameters of cancellous bone trabecula and its cancellous bone space BV/TV,TbN,TbTh,TbSp.Based on the obtained anatomical data,computer-aided software VG Studio MAX 3.4 was used to construct an osteochondral scaffold model with specific internal structure.Results The average thickness of the patellar cartilage was statistically greater than that of the lateral and medial condyles(P<0.05).The average thickness of the patellar subchondral bone plate was greater than that of the lateral and medial condyles(P<0.05).Patellar cartilage thickness/bone plate thickness was significantly lower than that of lateral condyle and medial condyle(P<0.05).Cancellous bone trabecular morphometric parameters TbSp and the morphometric parameter TbTh of the cancellous bone space were significantly different between the lateral condyle and the patellar surface(P<0.05).Using computer aided software VG Studio MAX 3,the digital model for non-degradable materials had the same three-dimensional structure as the normal osteochondral complex.The digital model for degradable materials had the same cartilage layer and subchondral bone plate structure as the normal cartilage and subchondral bone plate structure,and its scaffold layer structure was similar to the three-dimensional structure of the normal trabecular space.Conclusion There are certain differences in the microstructure characteristics of the osteochondral complex in different parts of human knee joint.Based on the Micro-CT data and computer-aided design,the digital three-dimensional model of the osteochondral scaffold can be accurately constructed.