Department of Mechanical Engineering, Boston University, USA.
Department of Mechanical Engineering, Boston University, USA; Department of Biomedical Engineering, Boston University, USA.
Osteoarthritis Cartilage. 2022 Aug;30(8):1130-1139. doi: 10.1016/j.joca.2022.03.013. Epub 2022 May 13.
Focal lesions within the subchondral bone, termed subchondral bone cysts (SBCs), are clinically accepted radiographic markers of advanced osteoarthritis (OA), but their etiology in the hip is not well understood.
This study used micro-computed tomography (μCT), and histological and immunocytological analysis to examine the prevalence, size, location, and morphological and cellular features of SBCs found within 34 femoral heads (14 male, 20 female; age range = 43-80 years) obtained from total hip arthroplasty procedures.
SBCs were common-present in 91% of the femoral heads examined-and frequently commuted with the surface of the femoral head, but otherwise showed no preferred anatomical location. Few associations were found between SBC features and patient characteristics such as BMI, age and sex. SBCs were also heterogenous in composition, ranging from fibrous (most common) to predominantly fatty (least common) and often containing vasculature, nerve fibers, cartilage islands, and bony spicules. Despite this heterogeneity, focal abnormalities in bone density and cartilage thickness were consistently observed. Bone adjacent to SBCs was denser than that in the primary compressive group, and cartilage thickness in regions overlying SBCs was lower than in non-overlying regions. In contrast to these local bony changes, μCT-based finite element analyses indicated that the stiffness of the primary compressive group was only mildly affected by SBCs.
These findings indicate that SBCs in the femoral head involve extensive perturbations in cellular activity, culminating in myriad skeletal tissue types and spatially heterogenous changes in bone and cartilage morphology that are likely to affect OA progression.
软骨下骨内的局灶性病变，称为软骨下骨囊肿（SBC），是公认的晚期骨关节炎（OA）的影像学标志物，但髋关节内的病因尚不清楚。
本研究使用微计算机断层扫描（μCT）以及组织学和免疫细胞化学分析，检查了 34 个股骨头（14 名男性，20 名女性；年龄范围为 43-80 岁）中发现的 SBC 的患病率、大小、位置以及形态和细胞特征，这些股骨头均来自全髋关节置换术。
SBC 很常见-在检查的 91％的股骨头中都有发现-并且经常与股骨头表面相通，但没有首选的解剖位置。SBC 特征与患者特征（如 BMI、年龄和性别）之间很少存在关联。SBC 的组成也不均匀，从纤维性（最常见）到主要脂肪性（最不常见），并且经常包含血管、神经纤维、软骨岛和骨刺。尽管存在这种异质性，但仍观察到骨密度和软骨厚度的局灶性异常。SBC 附近的骨头比原发性压缩组的骨头更密，而 SBC 上方区域的软骨厚度比非覆盖区域的软骨厚度低。与这些局部骨变化相反，基于 μCT 的有限元分析表明，原发性压缩组的刚度仅受 SBC 的轻度影响。
这些发现表明，股骨头中的 SBC 涉及细胞活性的广泛改变，最终导致多种骨骼组织类型以及骨和软骨形态的空间异质性变化，这可能会影响 OA 的进展。
