title: Effect of radiofrequency use on hip arthroscopy irrigation fluid temperature.
abstract: OBJECTIVE
  The purpose of this study was to determine operating parameters for joint fluid lavage using radiofrequency (RF) in maintaining intra-articular temperatures ≤50°C in the hip joint and to then quantify the influence of flow rate on maintaining safe intra-articular temperatures.
  
  
  METHODS
  Fiberoptic intra-articular thermometers at radial distance intervals of 1, 2, 5, and 10 mm, spanning cross-sectional areas of 3.14, 12.56, 78.5, and 314.1 mm(2), respectively, from the RF probe were used in 3 human hip cadaveric specimens at room temperature, with 9 trials per variable, using a 3-portal technique with a capsule release. Using a new Dyonics RF System continuously at the superior capsulolabral junction for 90 seconds, continuous temperatures were recorded at 50 mm Hg inflow and variable outflow intervals: no flow and 5, 15, and 30 seconds. Lavages were 1 second in duration on suction. Statistical comparison was through multivariate regression analysis and a logistic model.
  
  
  RESULTS
  Temperatures reached ≥50°C at 5-mm radial distance from the probe in all but the 5-second pulse lavage group. Elevated temperatures were reached within 1 to 2 seconds locally (1- to 2-mm radial distance) and at a radial distance of 5 mm in the 15-, 30-, and 0-second lavage groups. Logistic regression revealed a reduction in the odds that temperatures ≥50°C will occur as flow frequency increases every 30 (odds ratio = 0.68, P = .086); 15 (odds ratio = -1.22, P = .0067); and 5 (odds ratio = -4.26, P < .0001) seconds.
  
  
  CONCLUSIONS
  Increasing-interval pulsed irrigation is effective in maintaining intra-articular temperature profiles below 50°C during use of continuous RF ablation. Five-second-interval pulsed lavage is the longest flow interval identified during which fluid 5 mm radially from the RF device never reached temperatures >50°C.
  
  
  CONCLUSIONS
  Clinical guidelines for using the RF ablation include: meticulous technique, intermittent use, good inflow and outflow, and pulsed lavage at frequent intervals.
authors.affiliation: Rush Sports Medicine Fellowship Program, Midwest Orthopedics at Rush Sports Medicine, Chicago, Illinois, USA. Fmccormick@partners.org
authors.forename: Frank
authors.initials: F
authors.lastname: McCormick
authors.forename: Kyle
authors.initials: K
authors.lastname: Alpaugh
authors.forename: Benedict U
authors.initials: BU
authors.lastname: Nwachukwu
authors.forename: Siyan
authors.initials: S
authors.lastname: Xu
authors.forename: Scott D
authors.initials: SD
authors.lastname: Martin
mesh_terms: D001182:Arthroscopy; D001831:Body Temperature; D002102:Cadaver; D017115:Catheter Ablation; D006621:Hip Joint / Q000601:surgery*; D006801:Humans; D012996:Solutions; D007507:Therapeutic Irrigation
chemical_list: D012996:Solutions