Evaluation of electrosurgical meniscectomy in rabbits

Recently, electrosurgical cutting instruments utilizing radiofrequency energy have been designed as arthroscopic devices for cutting meniscal tissue. This study attempted to determine the in vivo gross and microscopic effects of radiofrequency energy on meniscal tissue in rabbits. Twelve adult New Zealand white rabbits (48 menisci) underwent bilateral knee arthrotomies. Ten rabbits (40 menisci) underwent partial meniscectomies in which one half of each meniscus in the longitudinal plane was removed with the electrosurgical generator. Two control rabbits underwent arthrotomy without resection of meniscal tissue. At specific time intervals, the rabbits were killed, and the menisci were removed. The gross specimens were photographed, and microscopic sections of each meniscus were fixed and stained. Specimens were evaluated to determine the cellular and vascular response to the electrosurgical cut edge of each meniscus. The microscopic specimens revealed that the radiofrequency cutting instruments produced a small degree of direct thermal damage to the cut meniscus. A tissue response producing a hypercellular dense collagen matrix was present for approximately 3 months. The spontaneous repair of tissue was complete by 6 months, and the histologic 6-month specimens could not be distinguished from the 6-month control specimens except with respect to the overall width of the specimens.