Early Alterations of Subchondral Bone in the Rat Anterior Cruciate Ligament Transection Model of Osteoarthritis

Abstract

Objective Advances in research have shown that the subchondral bone plays an important role in the propagation of cartilage loss and progression of osteoarthritis (OA), but whether the subchondral bone changes precede or lead to articular cartilage loss remains debatable. In order to elucidate the subchondral bone and cartilage changes that occur in early OA, an experiment using anterior cruciate ligament transection (ACLT) induced posttraumatic OA model of the rat knee was conducted. Design Forty-two Sprague Dawley rats were divided into 2 groups: the ACLT group and the nonoperated control group. Surgery was conducted on the ACLT group, and subsequently rats from both groups were sacrificed at 1, 2, and 3 weeks postsurgery. Subchondral bone was evaluated using a high-resolution peripheral quantitative computed tomography scanner, while cartilage was histologically evaluated and scored. Results A significant reduction in the subchondral trabecular bone thickness and spacing was found as early as 1 week postsurgery in ACLT rats compared with the nonoperated control. This was subsequently followed by a reduction in bone mineral density and bone fractional volume at week 2, and finally a decrease in the trabecular number at week 3. These changes occurred together with cartilage degeneration as reflected by an increasing Mankin score over all 3 weeks. Conclusions Significant changes in subchondral bone occur very early in OA concurrent with surface articular cartilage degenerative change suggest that factors affecting bone remodeling and resorption together with cartilage matrix degradation occur very early in the disease.

Terminal sterilization influences the efficacy of an extracellular matrix‐blood composite for treating posttraumatic osteoarthritis in the rat model

“…The majority of the changes in the cartilage after ACL transection appeared to be in the superficial and transitional zones of the medial compartment, with minimal changes to the deeper zones, consistent with prior reports in the ACL transection model 31–33 . When looking at the distribution of the cartilage damage severity in the current study, the medial compartments were more severely damaged than the lateral compartments, which is also consistent with prior reports 34 .…”

Increased expression of osteopontin in subchondral bone promotes bone turnover and remodeling, and accelerates the progression of OA in a mouse model

“…Absorption and destruction of the trabecular bone can be observed in the subchondral bone of patients with early OA [ 26 ]. Aizah et al found in an experimental animal model of OA that early subchondral bone trabeculae became thin and decreased, and bone mineral density and bone volume also decreased [ 27 ]. The activation and abnormal proliferation of osteoclasts are the key to the imbalance of bone resorption and bone metabolism.…”

Bioinformatics analysis of differentially expressed genes in subchondral bone in early experimental osteoarthritis using microarray data

“…In this analysis, we found that 588 DEGs between E-group and S-group. Bone remodeling is regulated by the balanced processes of osteoclast-mediated bone resorption and osteoblastmediated bone formation [13,14]. Disequilibrium of this balance leads to dysregulated bone tissue remodeling and can result in excessive bone loss or extra bone formation and consequent skeletal disease [15].…”