Cartilage debris increases the expression of chondrodestructive tumor necrosis factor-α by articular chondrocytes

Purpose: To determine if cartilage particles increased the expression of TNF-α by articular chondrocytes. Type of study: In vitro experiment. Methods: Articular chondrocytes were obtained from patients undergoing primary total knee arthroplasty for osteoarthritis (n = 3) and from patients undergoing below-knee amputation for peripheral vascular disease (n = 3). Chondrocytes were then incubated with and without cartilage particles at a concentration of 5 μg/10 ⁵ cells for 24 hours. TNF-α levels were then determined using reverse transcription polymerase chain reaction. Results: Both normal and osteoarthritic chondrocytes had low baseline expression of TNF-α under standard cell culture conditions. Expression was markedly increased in response to incubation with cartilage particles, and was statistically significant. Conclusions: Cartilage debris in the traumatized and osteoarthritic joint may increase the concentration of TNF-α in the joint, contributing to joint symptoms and cartilage destruction. Arthroscopic debridement and lavage may improve symptoms by washing these harmful components from the joint. Level of evidence: Level IV.