Abstract
Objective The aim of this study was to evaluate the effect of bipolar radiofrequency (RF) energy on canine stifle joint fluid temperature.
Materials and Methods A standard stifle arthroscopy was performed on 15 canine large breed cadaveric stifle joints. A bipolar RF (VAPR III, 2.3-mm side effect electrode; Depuy Mitek, Raynham, Massachusetts, United States) unit was activated in the joint (1) with or without direct tissue contact, (2) with or without additional 18-gauge needle outflow and (3) for 15 and 30 seconds. The joint fluid temperature was monitored with two fibre optic intra-articular sensors.
Results The stifle joint fluid temperature was significantly higher when there was no contact between the tissue and RF probe (mean: 58.6°C with 95% confidence interval [CI]: 53.3–64.0°C) compared with when tissue was contacted (mean: 29.0°C with 95% CI: 26.3–31.6°C). An 18-gauge egress needle had minimal effect on reducing joint fluid temperature. The temperature was higher during the 30-second application of RF energy than the 15-second group.
Clinical Significance Bipolar RF energy without firm tissue contact rapidly and significantly increased joint fluid temperature beyond the level reported to damage chondrocytes (above 45°C). Caution is required in the use of bipolar RF energy in the canine stifle joint.
Keywords
stifle joint - arthroscopy - radiofrequency energy - temperature - articular cartilage
