Abstract

Purpose: To morphohistologically evaluate the effect of four increasing intensities of bipolar radiofrequency (RF) on the human meniscus and to compare the changes seen in the menisci from patients younger and older than 40 years old. Methods: Thirty fresh menisci were divided in two groups. Group 1: 12 menisci from patients younger than 40 y.o.; Group 2: 18 menisci from patients older than 40 y.o. Groups 1 and 2 were divided in four zones and subjected in vitro, for 3 s, to four intensities of bipolar RF energy. The samples were studied macroscopically, and microscopically. Results: Thermal changes were present between 0 and 4000 ?m from the meniscal surface, with an average of 1699 ?m (S.D. 740), and was significantly higher on the ablation than the coagulation group (p < 0.001). We found a significant difference between the depth of thermal changes in the menisci from patients younger and older than 40 years old at medium intensities of RF energy (p = 0.038 and p = 0.044). Conclusions: Although bipolar RF can cause deep thermal changes (up to 4000 ?m) on the human meniscus, this effect depends on the magnitude of the energy applied. When comparing the effect between younger and older patients, the changes were deeper in the older group when RF was applied at medium intensities. Clinical relevance: Based on our findings, we recommend to exert precaution when applying RF energy at medium intensities in the degenerative meniscus, due to a deeper thermal effect in this group. © 2007 Elsevier B.V. All rights reserved.