Effects of radiofrequency energy on porcine articular cartilage: higher-power settings in ablation mode show lower thermal radiation injury

The purpose of this study was to compare the radiofrequency (RF) injury effect on cartilage in the different settings that are mostly used in clinical work under rigidly controlled laboratory conditions. Twelve fresh porcine knees were used in our study. Five treatment areas were created on the femoral condyles of each knee: the control group, coagulation (setting 2) group, coagulation (setting 7) group, ablation (setting 2) group, and ablation (setting 7) group. Hematoxylin/eosin staining, dual fluorescence staining, and the GAG content were observed to evaluate the histological cartilage changes, vacuolar cell rate of chondrocytes, depth of chondrocyte death, and detection of GAG content. Vacuolar cell rates of chondrocytes in each experimental group were higher than that in the control group (P < 0.05); there was no significant difference in vacuolar cell rate among experimental groups. Dual fluorescent staining showed that the ablation (setting 7) group had a smaller depth of cell death than did the coagulation (setting 2) group (P < 0.05); the other experimental groups showed no statistically significant difference (n.s.). In addition, there was no significant difference in GAG content between the experimental groups and control group (n.s.). The coagulation mode results in heavier thermal radiation injury to chondrocytes than does the ablation mode. Higher-power settings in the ablation mode result in lower thermal radiation injury and may be most suitable for cartilage debridement.