Wan Lu, de Asla Richard J, Rubash Harry E, Li Guoan
Bioengineering Laboratory, Department of Orthopaedic Surgery, Massachusetts General Hospital/Harvard Medical School, 55 Fruit Street, GRJ 1215, Boston, Massachusetts 02114, USA.
J Orthop Res. 2008 Aug;26(8):1081-9. doi: 10.1002/jor.20593.
Quantitative data on in vivo deformation of articular cartilage is important for understanding the articular joint function and the etiology of degenerative joint diseases such as osteoarthritis. This study experimentally determined the in vivo cartilage thickness distribution and articular cartilage contact strain distribution in human ankle joints under full body weight loading conditions using a combined dual fluoroscopic and magnetic resonance imaging technique. The average cartilage thickness with the joint non-weight bearing was found to be 1.43 mm +/- 0.15 mm and 1.42 mm +/- 0.18 mm in the distal tibial and proximal talar cartilage layers, respectively. During weight bearing on a single leg, the strain distribution data revealed that 42.4% +/- 15.7% of the contact area had contact strain higher than 15% in the ankle joint. Peak cartilage contact strain reached 34.5% +/- 7.3%. This quantitative data on in vivo human cartilage morphology and deformation demonstrated that the cartilage may undergo large deformations under the loading conditions experienced in human ankle joints during daily activities. The in vivo cartilage contact deformation can be used as displacement boundary conditions in three-dimensional (3D) finite element models of the joint to calculate in vivo 3D articular cartilage contact stress/strain distributions.
关节软骨体内变形的定量数据对于理解关节功能以及诸如骨关节炎等退行性关节疾病的病因至关重要。本研究使用双荧光镜和磁共振成像相结合的技术，通过实验确定了在全身负重条件下人体踝关节的体内软骨厚度分布和关节软骨接触应变分布。发现关节非负重时，胫骨远端和距骨近端软骨层的平均软骨厚度分别为1.43毫米±0.15毫米和1.42毫米±0.18毫米。在单腿负重期间，应变分布数据显示，踝关节接触区域的42.4%±15.7%的接触应变高于15%。软骨接触应变峰值达到34.5%±7.3%。这些关于人体软骨形态和体内变形的定量数据表明，在日常活动中人体踝关节所经历的负荷条件下，软骨可能会发生较大变形。体内软骨接触变形可作为关节三维（3D）有限元模型中的位移边界条件，以计算体内3D关节软骨接触应力/应变分布。
