title: What drives osteoarthritis?-synovial versus subchondral bone pathology.
abstract: Subchondral bone and the synovium play an important role in the initiation and progression of OA. MRI often permits an early detection of synovial hypertrophy and bone marrow lesions, both of which can precede cartilage damage. Newer imaging modalities including CT osteoabsorptiometry and hybrid SPECT-CT have underlined the importance of bone in OA pathogenesis. The subchondral bone in OA undergoes an uncoupled remodelling process, which is notably characterized by macrophage infiltration and osteoclast formation. Concomitant increased osteoblast activity leads to spatial remineralization and osteosclerosis in end-stage disease. A plethora of metabolic and mechanical factors can lead to synovitis in OA. Synovial tissue is highly vascularized and thus exposed to systemic influences such as hypercholesterolaemia or low grade inflammation. This review aims to describe the current understanding of synovitis and subchondral bone pathology and their connection in OA.
authors.affiliation: Osteoarthritis Research Center Basel.|Department of Rheumatology.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hügle
authors.affiliation: Osteoarthritis Research Center Basel.|Spine Surgery, University Hospital Basel, Basel, Switzerland.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Geurts
mesh_terms: D001847:Bone Diseases / Q000150:complications* / Q000000981:diagnostic imaging; D001855:Bone Marrow Diseases / Q000150:complications; D016723:Bone Remodeling; D006801:Humans; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000209:etiology*; D013583:Synovial Membrane / Q000473:pathology; D013585:Synovitis / Q000150:complications* / Q000000981:diagnostic imaging / Q000473:pathology
keywords: OA; bone; bone marrow lesion; crystal; inflammation; osteoarthritis; osteoimmunology; osteophyte; subchondral bone; synovitis