Lee Jee-Wook, Kobayashi Akio, Nakano Takayoshi
School of Advanced Materials Engineering, Kookmin University, Seoul, 136-702, Korea.
Department of Orthopaedic Surgery, Osaka City University, Graduate School of Medicine, Osaka, 545-8585, Japan.
J Bone Miner Metab. 2017 May;35(3):308-314. doi: 10.1007/s00774-016-0754-y. Epub 2016 Mar 29.
The aim of the present study was to investigate the preferred orientation of biological apatite (BAp) as a new index of the quality of subchondral bone (SB) in knee joint osteoarthritis (OA). Ten OA and five normal knee joints were obtained. Thickness, quantity and bone mineral density (BMD) of SB were analyzed at the medial condyle of the femur in dry conditions by peripheral quantitative computed tomography. In addition, the preferred crystallographic orientation of the c-axis of BAp was evaluated as bone quality parameter using a microbeam X-ray diffractometer technique. BMD and thickness of SB were significantly increased in OA specimens compared to normal knee specimens (P < 0.01), and the preferred orientation of the c-axis of BAp along the normal direction of SB surface was significantly higher in OA specimens (P < 0.01), reflecting the change in stress of concentration in the pathological portion without cartilage. SB sclerosis in OA results in both proliferation of bone tissues and enhanced degree of preferential alignment of the c-axis of BAp. Our findings could have major implications for the diagnosis of clinical studies, including pathologic elucidation in OA.
本研究的目的是探讨生物磷灰石（BAp）的择优取向，将其作为膝关节骨关节炎（OA）中软骨下骨（SB）质量的一项新指标。获取了10个OA膝关节和5个正常膝关节。通过外周定量计算机断层扫描，在干燥条件下分析股骨内侧髁处SB的厚度、数量和骨密度（BMD）。此外，使用微束X射线衍射仪技术评估BAp的c轴择优晶体取向，将其作为骨质量参数。与正常膝关节标本相比，OA标本中SB的BMD和厚度显著增加（P < 0.01），且OA标本中BAp的c轴沿SB表面法线方向的择优取向显著更高（P < 0.01），这反映了无软骨的病理部位应力集中的变化。OA中的SB硬化导致骨组织增殖以及BAp的c轴择优排列程度增强。我们的研究结果可能对临床研究的诊断具有重要意义，包括OA的病理阐释。
