A comparison of the effects of radiofrequency treatment and mechanical shaving for meniscectomy.
OBJECTIVE
The goal of this ex vivo pilot study was to compare radiofrequency treatment with cutting and shaving treatment of meniscal tears by use of a mechanical testing procedure and electron microscopy to establish the mechanical characteristics and qualitative appearance of meniscal tissue after the use of each of these procedures.


METHODS
In this study 136 menisci were explanted and divided into 4 groups: a damaged, untreated control group; a group damaged in the same way as the control group and treated by mechanical shaving of the meniscal tear; a group damaged in a similar way and then treated by radiofrequency by use of a radiofrequency wand; and a fourth group in which plunge-cutting by use of the radiofrequency wand was used to resect the tissue, beginning at the superior surface of the meniscus in a place that corresponded to the location of the meniscal tears. The menisci were then tested for strength by applying radial tension to the tear. Electron microscopy at low and high magnification was used to evaluate the appearance of the surface of the menisci after shaving or radiofrequency treatment.


RESULTS
Static mechanical testing to failure showed no significant difference between the control group and the 3 test groups. However, there was a statistically significant difference between the radiofrequency-treated groups and the mechanically shaved group at the .033 level. On fatigue testing, there was no statistically significant difference in the failure cycles, but the coefficient of variation was 8 times greater for the mechanically shaved menisci versus the radiofrequency-treated menisci. Scanning electron microscopy showed that the mechanically treated menisci had flat surfaces with clefts or fissures. The radiofrequency-treated menisci had a homogeneous appearance without clefts.


CONCLUSIONS
This study showed that radiofrequency-treated damaged tissue leaves a qualitatively different surface from the mechanically treated menisci, which failed at a significantly higher load on static testing. On fatigue testing, there was greater variation in the number of cycles to failure of mechanically treated specimens versus the radiofrequency-treated menisci.


CONCLUSIONS
Although recurrent meniscal tears are uncommon, they may be of value in evaluating different methods of meniscectomy. This study points out mechanical and qualitative differences between shaved and radiofrequency-treated meniscectomy.
Grana
William A
WA
Department of Orthopaedic Surgery, University of Arizona, Tucson, Arizona, USA. clawrenc@email.arizona.edu
Szivek
John A
JA
Schnepp
Andrew B
AB
Ramos
Renata
R
D000818:Animals; D001696:Biomechanical Phenomena; D017115:Catheter Ablation / Q000379:methods*; D008422:Materials Testing; D008592:Menisci, Tibial / Q000473:pathology* / Q000601:surgery*; D008855:Microscopy, Electron, Scanning; D010865:Pilot Projects; D012756:Sheep