膝关节软骨人体标本解剖与磁共振成像的比较研究

MR imaging and anatomic study of articular cartilage of the knee joint

目的 探讨膝关节尸体标本解剖与磁共振成像（MRI）三维序列-扰相梯度回波序列（3D—FS—SPGR）测量关节软骨厚度的差异，并分析软骨组织主要成分在关节软骨不同位置的差异。方法 选用国人青壮年中等身材、无明显关节病变的成年男性尸体膝关节标本2具，首先进行3D—FS—SPGR序列矢状位扫描。复冻后按解剖部位进行矢状位解剖，分别对股骨及胫骨内、外髁负重区前、后面及髌骨面软骨厚度进行测量。关节软骨石蜡切片进行维多利亚蓝一丽春红复合染色并观察。结果 软骨尸体标本解剖与3D—FS—SPGR序列测得的膝关节软骨厚度：股骨外侧髁前负重面平均分别为2．25、2．25mm，股骨外侧髁后负重面平均分别为2．70、2．75mm，胫骨外侧髁前负重面平均分别为2．00、2．10mm；胫骨外侧髁后负重面平均分别为2．35、2．25mm，股骨内侧髁前负重面平均分别为2．20、2．20mm，股骨内侧髁后负重面平均分别为2．15、2．30mm，胫骨内侧髁前负重面平均分别为2．20、2．45mm，胫骨内侧髁后负重面平均分别为2．70、2．95mm,髌骨面软骨平均分别为3．08、3．15mm。软骨组织学染色显示：关节软骨表层胶原纤维含量相对较多，软骨细胞及其周围基质相对较少；在关节软骨深层，胶原纤维含量相对较少，而软骨及软骨周围基质相对较多。结论 3D—FS—SPGR序列能够相对真实地反映关节软骨的形态及厚度。胶原纤维主要集中在软骨表层，其分布与软骨的功能相一致。

Objective To compare corpse sampling and MR imaging with 3D-FS-SPGR sequences in measurement of the articular cartilage thickness and to investigate knee cartilage topography. Methods Two fresh specimens of the knee joint were obtained from 2 normal young adult male corpses of medium stature. MRI scanning was carried on the 2 specimens in sagittal 3D-FS-SPGR MR sequences. After defrosted, the knee specimens were dissected longitudinally, and the cartilage thicknesses were measured at different locations of the knee joint. Paraffin sections of the knee cartilage were observed following compound staining with victoria blue and ponceau red. Results The average cartilage thicknesses measured by dissection and MR imaging sequence were respectively： 2.25 mm and 2.25 mm at the anterior weight-loading surface of the femoral lateral condyle, 2.70 mm and 2.75 mm at the posterior weight-loading surface of the femoral lateral condyle, 2. 00 mm and 2. 10 mm at the anterior weight-loading surface of the tibial lateral condyle, 2.35 mm and 2. 25 mm at the posterior weight-loading surface of the tibial lateral condyle, 2. 20 mm and 2.20 mm at the anterior weight-loading surface of the femoral medial condyle, 2.15 mm and 2.30 mm at the posterior weight-loading surface of the femoral medial condyle, 2. 20 mm and 2.45 mm at the anterior weight-loading surface of the tibial medial condyle, 2.70 mm and 2.95 mm at the posterior weight-loading surface of the tibial medial condyle and 3.08 mm and 3.15 mm at patella cartilage surface. Collagen fibers were rich at the periphery of the articular cartilage with sparse chondrocytes and matrixes, while the opposite was observed at the center of the articular cartilage. Conclusions MR imaging with 3D-FS-SPGR sequences can display the actual knee cartilage topography. Collagen fibers mainly concentrate at the periphery of the articular cartilage, which accounts for the function of the articular cartilage.