Articular cartilage and synovial surface

Articular cartilage is a specialized, avascular connective tissue that covers the epiphyses of bones within synovial joints (StatPearls, PMID: 30725642). It consists primarily of an extracellular matrix (ECM) composed of type II collagen and aggrecan, maintained by a sparse population of chondrocytes (Sports Health, 2009). The synovial surface, lined by the synovium, produces synovial fluid which provides lubrication and nutrients to the cartilage (Wiley Interdiscip Rev Syst Biol Med, 2012). Together, these structures ensure low-friction movement and shock absorption during physical activity (Matrix Biology, 2014). In diseases like osteoarthritis, the balance between ECM synthesis and degradation is disrupted, leading to progressive cartilage loss and joint pain (Nature Reviews Disease Primers, 2016). Pharmacological interventions often target this environment through intra-articular injections of viscosupplements like hyaluronic acid to restore joint lubrication (Physician and Sportsmedicine, 2015). Emerging therapies also investigate the use of growth factors or lubricin mimetics to protect the synovial surface and promote tissue regeneration (Nature Reviews Rheumatology, 2013). Because this target represents a complex anatomical structure rather than a single molecule, it is considered a tissue-level therapeutic site rather than a molecular receptor.

Other names

Hyaline cartilageJoint surfaceSynovial membrane surfaceArticular surface

Drugs targeting this surface typically act through viscosupplementation, where exogenous substances like hyaluronic acid are injected to restore the rheological properties of synovial fluid, thereby reducing friction and protecting the cartilage surface (Altman et al., 2015). Other mechanisms include the use of boundary lubricants like lubricin to prevent direct contact between articular surfaces (Jay & Waller, 2014).