Source and hub of inflammation: The infrapatellar fat pad and its interactions with articular tissues during knee osteoarthritis.

Abstract

Knee osteoarthritis, the most prevalent degenerative joint disorder worldwide, is driven by chronic low-grade inflammation and subsequent cartilage degradation. Clinical data on the role of the Hoffa or infrapatellar fat pad in knee osteoarthritis are, however, scarce. The infrapatellar fat pad is a richly innervated intracapsular, extrasynovial adipose tissue, and an abundant source of adipokines and proinflammatory and catabolic cytokines, which may contribute to chronic synovial inflammation, cartilage destruction, and subchondral bone remodeling during knee osteoarthritis. How the infrapatellar fat pad interacts with neighboring tissues is poorly understood. Here, we review available literature with regard to the infrapatellar fat pad's interactions with cartilage, synovium, bone, menisci, ligaments, and nervous tissue during the development and progression of knee osteoarthritis. Signaling cascades are described with a focus on immune cell populations, pro- and anti-inflammatory cytokines, adipokines, mesenchymal stromal cells, and molecules derived from conditioned media from the infrapatellar fat pad. Understanding the complex interplay between the infrapatellar fat pad and its neighboring articular tissues may help to better understand and treat the multifactorial pathogenesis of osteoarthritis.

• Authors: Sijia Zhou, Tazio Maleitzke, Sven Geissler, Alexander Hildebrandt, Florian Nima Fleckenstein, Marcel Niemann, Heilwig Fischer, Carsten Perka, Georg N Duda, Tobias Winkler
• Journal: Journal of orthopaedic research : official publication of the Orthopaedic Research Society (J Orthop Res) Vol. 40 Issue 7 Pg. 1492-1504 (07 2022) ISSN: 1554-527X [Electronic] United States
• PMID: 35451170 (Publication Type: Journal Article, Review)
• Copyright: © 2022 The Authors. Journal of Orthopaedic Research ® published by Wiley Periodicals LLC on behalf of Orthopaedic Research Society.

Chemical References

• Adipokines
• Cytokines

Topics

• Adipokines (metabolism)
• Adipose Tissue (metabolism)
• Cytokines (metabolism)
• Humans
• Inflammation (metabolism)
• Knee Joint (pathology)
• Osteoarthritis, Knee (pathology)