Working conditions of bipolar radiofrequency on human articular cartilage repair following thermal injury during arthroscopy

Background The thermal injury during bipolar radiofrequercy results in chondrocyte death that limits cartilage repair.The purpose was to determine the effects of various factors of bipolar radiofrequency on human articular cartilage after thermal injury,offering suitable working conditions for bipolar radiofrequency during arthroscopy.Methods Osteochondral explants from 28 patients undergoing total knee arthroplasty （TKA） in Department of Orthopaedic,Peking University Reople＇s Hospital from October 2013 to May 2014,were harvested and treated using bipolar radiofrequency in a light contact mode under the following conditions：various power setting of levels 2,4 and 6; different durations of 2 seconds,5 seconds and 10 seconds; irrigation with fluids of different temperatures of 4℃,22℃,and 37℃; two different bipolar radiofrequency probes ArthroCare TriStar 50 and Paragon T2.The percentage of cell death and depth of cell death were quantified with laser confocal microscopy.The content of proteoglycan elution at different temperatures was determined by spectrophotometer at 530 nm.Results Chondrocyte mortality during the treatment time of 2 seconds and power setting of level 2 was significantly lower than that with long duration or in higher level groups （time：P=0.001; power：P=0.001）.The percentage of cell death after thermal injury was gradually reduced by increasing the temperature of the irrigation solutions （P=0.003）,the depth of dead chondrocytes in the 37℃ solution group was significantly less than those in the 4℃ and 22℃ groups （P=0.001）.The proteoglycan elution was also gradually reduced by increasing the temperature （P=0.004）.Compared with the ArthroCare TriStar 50 group,the percentage of cell death in the Paragon T2 group was significantly decreased （P=0.046）.Conclusions Thermal chondroplasty with bipolar radiofrequency resulted in defined margins of chondrocyte death under controlled conditions.The least cartilage damage during thermal chondroplasty could be achieved with lower power,shorter duration,suitable temperature of irrigation solutions and chondroprotective probes.The recommendations for the use of bipolar radiofrequency to minimize cartilage damage could be achieved with a power setting of level 2,treatment duration of 2 seconds,suitable fluid temperature （closer to body temperature of 37℃） and chondroprotective Paragon T2 probes.

Fluoroscopy-guided Bipolar Radiofrequency Thermocoagulation Treatment for Discogenic Low Back Pain

Background：The efficacy of percutaneous intradiscal radiofrequency thermocoagulation （PIRFT） for the treatment of discogenic low back pain （LBP） remains controversial.However,all the PIRFT studies utilized monopolar radiofrequency thermocoagulation （RFTC）.The aim of this study was to investigate the safety and efficacy of bipolar RFTC for the treatment of discogenic LBP.Methods：A total of 23 patients with discogenic LBP were treated with single-level bipolar RFTC.The patients were assessed before the procedure and at 1 week,1 month,3 months,6 months,and 1 year after the procedure.The primary outcome included the visual analog scale （VAS） score and the Oswestry Disability Index （ODI） score.The secondary outcome included pain relief,reduction of analgesic dose,and patient satisfaction.Results：The VAS and ODI scores were significantly decreased after bipolar RFTC treatment at all time points of follow-up （P 〈 0.05）.Bipolar RFTC treatment also resulted in a significant change in all secondary measures,such as pain relief,reduction of analgesic dose,and patient satisfaction.No serious complications or neurological sequelae were observed in any of the patients.Conclusions：Bipolar RFTC treatment can significantly attenuate pain and improve the function of patients with discogenic LBP.

Expert consensus of Chinese Association for the Study of Pain on the radiofrequency therapy technology in the Department of Pain

On the basis of continuous improvement in recent years,radiofrequency therapy technology has been widely developed,and has become an effective method for the treatment of various intractable pain.Radiofrequency therapy is a technique that uses special equipment and puncture needles to output ultra-high frequency radio waves and accurately act on local tissues.In order to standardize the application of radiofrequency technology in the treatment of painful diseases,Chinese Association for the Study of Pain(CASP)has developed a consensus proposed by many domestic experts and scholars.