The effects of lipid depletion on osteoarthritic wear

The surface of articular cartilage is covered with a superficial layer of high phospholipids concentration. The lubrication and hydrophobic properties of this layer appear to play an important role in synovial joint functioning. In this work it has been hypothesised that removal of the cartilage surface lipid layer is the key factor in the onset of osteoarthritis (OA). The aim of this research was to prove that destruction of the lipid layer accelerates wear and osteoarthritic damage. Special wear experiments have been conducted on intact sheep joints, aiming to compare ‘naturally worn’ joints and joints injected with lipid solvent prior to wear tests. Microscopic analysis has shown greatly accelerated osteoarthritic damage to the articular cartilage of lipid depleted joints. Wear particles extracted from synovial fluid have also been examined, with quantitative computer analysis confirming the above result and also demonstrating a direct correlation between lipid depleted sheep joints and osteoarthritic human joints.