Li Yunfei, Liem Yulia, Dall'Ara Enrico, Sullivan Niall, Ahmed Haroon, Blom Ashley, Sharif Mohammed
Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
Department of Oncology and Metabolism and Insigneo Institute for in silico Medicine, University of Sheffield, Sheffield, UK.
J Orthop Res. 2021 Dec;39(12):2568-2580. doi: 10.1002/jor.25018. Epub 2021 Mar 19.
Osteoarthritis (OA) and osteoporosis (OP) are historically considered to be inversely correlated but there may be an overlap between the pathophysiology of the two diseases. This study aimed to investigate the subchondral bone microarchitecture and matrix mineralization, and the association between them in OA and OP in relation to the degree of cartilage degeneration. Fifty-six osteochondral plugs were collected from 16 OA femoral heads. They were graded on a regional basis according to the stages of cartilage degeneration, as evaluated by a new macroscopic and a modified microscopic grading system. Twenty-one plugs were collected from seven femoral heads with OP. Plugs were scanned by microcomputed tomography and the microarchitectural and mineral properties were obtained for both subchondral plate and trabecular bone. Microarchitecture and material and apparent densities of subchondral bone in OP were similar to regions with early cartilage degeneration but different from regions with advanced cartilage degradation in OA femoral heads. Subchondral trabecular bone was more mineralized than subchondral plate in both OP and OA, and this compartmental difference varied by severity of cartilage degradation. Furthermore, the relationship among trabecular bone volume fraction, tissue mineral density, and apparent bone density was similar in OP and different stages of OA. Subchondral bone microarchitecture and mineral properties in OP are different from OA in a regionalized manner in relation to stages of cartilage degeneration. Both regional and compartmental differences at structural, material, and cellular levels need to be studied to understand the transition of OA subchondral bone from being osteoporotic to sclerotic.
骨关节炎（OA）和骨质疏松症（OP）在历史上被认为是负相关的，但这两种疾病的病理生理学之间可能存在重叠。本研究旨在调查软骨下骨微结构和基质矿化情况，以及它们在OA和OP中与软骨退变程度的相关性。从16个OA股骨头中收集了56个骨软骨栓。根据软骨退变阶段，通过一种新的宏观和改良微观分级系统进行评估，将它们按区域分级。从7个OP股骨头中收集了21个栓。通过微型计算机断层扫描对栓进行扫描，获得软骨下板和松质骨的微结构和矿物质特性。OP中软骨下骨的微结构、材料密度和表观密度与OA股骨头中软骨早期退变区域相似，但与软骨严重退变区域不同。在OP和OA中，软骨下松质骨的矿化程度均高于软骨下板，且这种区域差异随软骨退变严重程度而变化。此外，OP和OA不同阶段中，松质骨体积分数、组织矿物质密度和表观骨密度之间的关系相似。OP中软骨下骨微结构和矿物质特性与OA在软骨退变阶段方面存在区域化差异。需要研究结构、材料和细胞水平上的区域和区域间差异，以了解OA软骨下骨从骨质疏松到硬化的转变。
