In vivo temperature measurement in the subacromial bursa during arthroscopic subacromial decompression

BackgroundThe purpose of the study was to evaluate whether use of a bi-polar radiofrequency (RF) ablation wand would cause excess heating, which may lead to collateral damage to the surrounding tissues during arthroscopic subacromial decompression. Cadaveric studies have shown that high temperatures can potentially be reached when using RF ablation wands in arthroscopic shoulder surgery. Only 1 other published study assesses these temperature rises in the clinical setting.MethodsFifteen patients were recruited to participate in the study. A standard arthroscopic subacromial decompression was performed using continuous flow irrigation, with intermittent use of the RF ablation wand for soft tissue debridement. The temperature of the irrigation fluid within the subacromial bursa and the outflow fluid from the suction port of the wand were measured during the procedure using fiber-optic thermometers.ResultsThe mean peak temperature recorded in the subacromial bursa was 32.0°C (29.3-43.1°C), with a mean rise from baseline of 9.8°C. The mean peak temperature recorded from the outflow fluid from the wand was 71.6°C (65.6-77.6°C), with a mean rise from baseline of 49.4°C.ConclusionHigh temperatures were noted in the outflow fluid from the wand; however, this was not evident in the subacromial bursa itself. Use of room temperature inflow fluid, maintenance of flow through the bursa, and avoidance of prolonged uninterrupted use of the wand all appear to ensure that safe temperatures are maintained in the subacromial bursa not only in the laboratory but also in a clinical setting.