Subchondral Bone Features and Mechanical Properties as Biomarkers of Osteoarthritis

Abstract

Osteoarthritis (OA) is a painful, debilitating disease most characterized by cartilage degeneration at joint surfaces. In addition to cartilage degeneration, OA is marked by bony changes including attrition, osteophyte formation, cyst presence, bone marrow lesions, altered shape, as well as altered density and mechanical properties of underlying subchondral bone. As subchondral bone is densely innervated, it may be a plausible site of debilitating pain associated with OA. However, the role of subchondral bone in OA pathogenesis and pain remains unclear. Medical imaging offers the ability to quantitatively characterize and monitor subchondral bone properties in vivo in people living with OA and investigate changes in relation to clinical OA symptoms. Incorporating medical imaging data with computational finite element modeling enables study of bone mechanical properties in the OA affected joint. These imaged-based biomarkers have potential to elucidate the mechanism underpinning OA pain and clarify the role of mechanical loading in OA pathogenesis. By characterizing and monitoring subchondral bone features and mechanical properties, image-based biomarkers provide unique, noninvasive avenues to improve our understanding of OA initiation, progress, and treatment. This chapter will summarize recent evidence of associations between subchondral bone features and mechanical properties as biomarkers of OA onset, progression, and pain initiation.