Effect of radiofrequency energy on glenohumeral fluid temperature during shoulder arthroscopy

Background: Reports of glenohumeral chondrolysis following arthroscopy have raised concern about the deleterious effects that thermal devices may have on articular cartilage. The purpose of this study was to investigate the effects of flow and duration of treatment with a thermal device on temperatures within cadaveric glenohumeral joint specimens. It was hypothesized that the use of a thermal device during surgery increases the temperature of fluid within the joint to >45°C, which has been shown to cause chondrocyte death. Methods: Temperature was measured at four locations within ten cadaver shoulder joints. Eight heating trials were performed on each cadaver shoulder to test three variables: the method of heating (continuous or intermittent), the fluid-pump flow rate (no flow, 50% flow, or 100% flow), and the location of the radiofrequency probe (the radiofrequency energy was either applied directly to anterior capsular tissue in a paintbrush pattern or held adjacent to the glenoid without tissue contact). Results: Temperatures of >45°C occurred in every trial. The average maximum temperatures in all no-flow conditions were significantly higher than those in the trials with flow. Higher temperatures were measured by the anterior probe in all trials. When the heating had been applied adjacent to the glenoid, without tissue contact, the time needed to cool to a safe temperature was significantly longer in the no-flow states (average, 140.5 seconds) than it was in the 50% flow states (average, 12.5 seconds) or the 100% flow states (average, 8.5 seconds). Conclusions: Use of a thermal probe during arthroscopy may cause joint fluid temperatures to reach levels high enough to cause chondrocyte death. Maintaining adequate fluid-pump flow rates may help to lower joint fluid temperatures and protect articular cartilage. Clinical Relevance: The use of radiofrequency devices according to the manufacturer's recommendations in situations similar to clinical scenarios can result in exposure of chondrocytes to temperatures high enough to cause their death (>45°C). While this complication is rare, this study emphasizes that care must be taken when using these devices; precautions include minimization of direct chondrocyte exposure and maintenance of adequate flow rates.