Spatial links between subchondral bone architectural features and cartilage degeneration in osteoarthritic joints

Abstract

Early diagnosis of osteoarthritis (OA), before the onset of irreversible changes is crucial for understanding the disease process and identifying potential disease-modifying treatments from the earliest stage. OA is a whole joint disease and affects both cartilage and the underlying subchondral bone. However, spatial relationships between cartilage lesion severity (CLS) and microstructural changes in subchondral plate and trabecular bone remain elusive. Herein, we collected femoral heads from hip arthroplasty for primary osteoarthritis (n = 7) and femoral neck fracture (n = 6; non-OA controls) cases. Samples were regionally assessed for cartilage lesions by visual inspection using Outerbridge classification and entire femoral heads were micro-CT scanned. Scans of each femoral head were divided into 4 quadrants followed by morphometric analysis of subchondral plate and trabecular bone in each quadrant. Principal component analysis (PCA), a data reduction method, was employed to assess differences between OA and non-OA samples, and spatial relationship between CLS and subchondral bone changes. Mapping of the trabecular bone microstructure in OA patients with low CLS revealed trabecular organisation resembling non-OA patients, whereas clear differences were identifiable in subchondral plate architecture. The OA-related changes in subchondral plate architecture were summarised in the first principle component (PC1) which correlated with CLS in all quadrants, whilst by comparison such associations in trabecular bone were most prominent in the higher weight-bearing regions of the femoral head. Greater articular cartilage deterioration in OA was regionally-linked with lower BV/TV, TMD and thickness, and greater BS/BV and porosity in the subchondral plate; and with thinner, less separated trabeculae with greater TMD and BS/BV in the trabecular bone. Our findings suggest that impairment of subchondral bone microstructure in early stage of OA is more readily discernible in the cortical plate and that morphological characterisation of the femoral head bone microstructure may allow for earlier OA diagnosis and monitoring of progression.

Endothelial Stat3 activation promotes osteoarthritis development

“…Currently, subchondral bone deterioration is thought to precede the onset of cartilage damage 23,24 . Meanwhile, subchondral bone abnormal angiogenesis is observed in OA samples 11,25 .…”

“…Currently, subchondral bone deterioration is thought to precede the onset of cartilage damage. 23 , 24 Meanwhile, subchondral bone abnormal angiogenesis is observed in OA samples. 11 , 25 Therefore, we collected tibial plateaus from two OA patients to investigate the underlying mechanisms regulating subchondral bone ECs.…”

Multiple roles of ALK3 in osteoarthritis

“…Therefore, the corresponding changes such as reduction in subchondral plate mineralization density may indicate the early stages of OA, and we should pay attention to this in order to intervene early in the development of OA. 31 In addition, Zhen et al 32 found that increased TGFβ1 in subchondral bone can significantly increase subchondral bone volume and angiogenesis, significantly reduce proteoglycan expression, and thin the hyaline cartilage layer, thus inducing the joint to display OA phenotype, whereas inhibition of TGFβ activity in subchondral bone can inhibit OA progression. In the joint region, there are many potential instances of molecular crosstalk within and between tissues.…”

Study on the efficacy and mechanism of Jintiange Capsules in the tre atment of osteoarthritis in rats

“…It has been reported that there is a complex interaction between cartilage and subchondral bone. Many literatures show that that signi cant changes of subchondral bone remodeling occurred at the very early stage in a rat OA model, and alternations in subchondral bone emerged earlier than cartilage degeneration 8, 22,23 . Micro-CT scans revealed a signi cant increase in the number of trabeculae in the JTG group, which were well aligned, closely spaced, and signi cantly thicker.…”