Meniscal debridement with an arthroscopic radiofrequency wand versus an arthroscopic shaver: comparative effects on menisci and underlying articular cartilage.

PURPOSE Meniscal debridement with an arthroscopic radiofrequency (RF) wand versus an arthroscopic shaver and their comparative effects on menisci and underlying articular cartilage were studied. METHODS When repair is not feasible, degenerative or post-traumatic meniscal tears often need debridement. Six fresh bovine knees were harvested, the tibial plateau was dissected free from the femoral articulation and placed in a saline bath at 28 degrees C, with 10% to 15% of the posterior horn of menisci debrided arthroscopically, and the surfaces debrided using a basket punch plus shaver, punch plus RF wand, RF wand alone, and untreated control. Treatment time of each case was 24 seconds at wand power 7. We characterized an injury zone, as well as viability and metabolic activity of meniscal cells and tibial articular cartilage chondrocytes. RESULTS Chondrocyte viability of the tibial articular surface was 96% to 98%. We saw no differences in viability or injury zone (0 to 150 microm) among debrided groups or versus the control for any experimental surface, with no significant difference in metabolic activity in menisci debrided surfaces versus control. Meniscal viability was variable with analyses showing substantial levels (150 to 500 microm) of cell death in debrided and control groups. Metabolic activity in treated meniscus was lower than in cartilage specimens. No significant differences were observed among treatment groups versus control. CONCLUSIONS Focal areas of chondrocyte cell death were not seen. Meniscal samples showed cell death (150 to 500 mum) throughout the tissue. CLINICAL RELEVANCE Debridement of menisci with a bipolar RF wand produces levels of cell injury and death similar to those of debridement with a basket punch mechanical shaver. The RF wand did not harm underlying articular surfaces and produced a precise cut to the meniscal surface.