Effect of bipolar radiofrequency energy on human articular cartilage: Comparison of confocal laser microscopy and light microscopy

Abstract

Purpose: To evaluate chondrocyte viability using confocal laser microscopy (CLM) following exposure to bipolar radiofrequency energy (bRFE) and to contrast CLM with standard light microscopy (LM) techniques. Type of Study: In vitro analysis using chondromalacic human cartilage. Methods: Twelve fresh chondral specimens were treated with the ArthroCare 2000 bRFE system (ArthroCare, Sunnyvale, CA) coupled with 1 of 2 types of probes and at 3 energy delivery settings (S2, S4, S6). A sham-operated group was treated with no energy delivered. Specimens were analyzed for chondrocyte viability and chondral morphology with CLM using fluorescent vital cell staining and with LM using H&E and safranin-O staining. Results: LM with H&E staining showed smoothing of fine fronds of fibrillated cartilage; thickened fronds were minimally modified. Chondrocyte nuclei were present and not morphologically different than nuclei within sham-operated and adjacent untreated regions. LM with safranin-O staining showed a clear demarcation between treated and untreated regions. CLM, however, showed chondrocyte death: the depth and width of chondrocyte death increased with increasing bRFE settings. Conclusions: CLM showed that bRFE delivered through the probes investigated created significant chondrocyte death. These changes were not apparent using LM techniques.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 2 (February), 2001: pp 117–123