Temporal progression of subchondral bone alterations in OA models involving induction of compromised meniscus integrity in mice and rats: A scoping review

Abstract

Objective: To categorize the temporal progression of subchondral bone alterations induced by compro mising meniscus integrity in mouse and rat models of knee osteoarthritis (OA). Method: Scoping review of investigations reporting subchondral bone changes with appropriate negative controls in the different mouse and rat models of OA induced by compromising meniscus integrity. Results: The available literature provides appropriate temporal detail on subchondral changes in these models, covering the entire spectrum of OA with an emphasis on early and mid-term time points. Microstructural changes of the subarticular spongiosa are comprehensively described; those of the sub chondral bone plate are not. In mouse models, global subchondral bone alterations are unidirectional, in volving an advancing sclerosis of the trabecular structure over time. In rats, biphasic subchondral bone alterations begin with an osteopenic degeneration and loss of subchondral trabeculae, progressing to a late sclerosis of the entire subchondral bone. Rat models, independently from the applied technique, relatively faithfully mirror the early bone loss detected in larger animals, and the late subchondral bone sclerosis observed in human advanced OA. Conclusion: Mice and rats allow us to study the microstructural consequences of compromising meniscus integrity at high temporal detail. Thickening of the subchondral bone plate, an early loss of thinner sub articular trabecular elements, followed by a subsequent sclerosis of the entire subchondral bone are all important and reliable hallmarks that occur in parallel with the advancing articular cartilage degeneration. Thoughtful decisions on the study design, laterality, selection of controls and volumes of interest are crucial to obtain meaningful data.