Time-Dependent Effects of Arthroscopic Conditions on Human Articular Cartilage: An In Vivo Study

Abstract

To assess time-dependent effects of arthroscopic conditions on human articular cartilage invivo. From each of 10 patients undergoing multiligament reconstruction of the knee under our routine arthroscopic conditions (gravity irrigation of 0.9% normal saline solution at room temperature with 150cmH2O [110mm Hg] pressure and pneumatic tourniquet under 270mm Hg pressure), cartilage specimens were harvested from the lateral edge of the femoral notch at the beginning of the operation (baseline) and at 15-, 30-, 45-, and 60-minute time points during the operation. H&E staining and safranin O staining were used to evaluate the tissue structure, chondrocytes, and extracellular matrix (ECM) of the articular cartilage. Chondrocyte viability was evaluated, and a biochemical examination of the ECM was performed to detect changes in glycosaminoglycan and collagen content. The expression levels of genes associated with proinflammatory cytokines, ECM metabolism, and chondrocyte apoptosis of the articular cartilage were evaluated. At the 45- and 60-minute time points, an obvious impairment of tissue structure, a significant decrease in glycosaminoglycan content, and a significantly lower percentage chondrocyte viability were observed, as compared with baseline (P < .05). Regarding the tissue collagen content, no significant change was detected at any time point (P > .05). The gene expression examination at the 45- and 60-minute time points detected significant upregulation of interleukin 1β and tumor necrosis factor α (P < .05), indicating an inflammatory response by the chondrocytes, and significant upregulation of aggrecanase 1 (P < .05), which indicates catabolism or the disturbance of aggrecan metabolism. Under current arthroscopic conditions, an operative duration of 45minutes or longer can cause detrimental structural, biochemical, and metabolic effects on human articular cartilage. Arthroscopic skills should always be improved to reduce operation time and thus minimize the potential detrimental effects of arthroscopic conditions on articular cartilage.