Osteoarthritis year in review 2021: biology

This year in review on osteoarthritis biology summarizes a series of research articles published between the 2020 and 2021 Osteoarthritis Research Society International (OARSI) World Congress. Research hightlights were selected and discussed based on the new discoveries of OA's cellular molecular mechanism, anatomical signatures, potential therapeutic targets, and regenerative therapy. The recently developed potential therapeutic targets are summarized, and the research focuses on TGF13 and WNT signaling in joint tissue homeostasis, joint aging and the dynamic of synolytics in OA joint, and the roles of TRP2, LDHA, OSCAR in cartilage homeostasis and OA joints are highlighted. Subsquencially, new anatomical structures and OA features are introduced, such as synovitis-induced venous portal circulation, horiozontal fissures between cartilage and subchondral bone, the cellular derivation of osteophytes formation, OA subtypes, and subchondral remodeling and pain biology. Then, research on the possibility of tissue regeneration in OA joints are discussed; skeletal stem cells in OA cartilage regeneration, and preclinical results of regenerative therapy for meniscus tear and osteochondral tissue morphoghesis are included. At last, the clinical evidence of the importance of delivery site of bone marrow stem cells for OA treatment is discussed. These findings represent advances in our understanding of OA pathophysiology. (c) 2021 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Automated summary

This review on osteoarthritis biology summarizes a series of research articles published between the 2020 and 2021 Osteoarthritis Research Society International (OARSI) World Congress. It focuses on the new discoveries of osteoarthritis's cellular molecular mechanism, anatomical signatures, potential therapeutic targets, and regenerative therapy. The review highlights the recently developed potential therapeutic targets, such as TGF13 and Wnt signaling, and discusses their roles in joint tissue homeostasis, joint aging, and cartilage homeostasis. It also introduces new anatomical structures and osteoarthritis features and discusses the possibility of tissue regeneration in osteoarthritis joints. Lastly, it discusses the clinical evidence of the importance of delivery site of bone marrow stem cells for osteoarthritis treatment.