title: The effect of body mass index on fluoroscopy time and radiation dose in intra-articular glenohumeral joint injections.
abstract: OBJECTIVE
  To determine the relationship between body mass index (BMI) and fluoroscopy time and radiation dose during fluoroscopy-guided glenohumeral joint injections.
  
  
  METHODS
  This was a retrospective analysis of prospectively collected data. Physicians with board certification in Physical Medicine and Rehabilitation and/or Sports Medicine performed or supervised all injections. BMI was calculated within three months of the injection. Fluoroscopy time and radiation dose data were recorded by the fluoroscopy system and transcribed into the clinical database after each procedure.
  
  
  RESULTS
  A total of 335 intra-articular GHJ injections were performed, 230 on the right shoulder and 105 on the left shoulder; none were bilateral. The mean fluoroscopy time for all injections was 18.8±12.6s, and the mean radiation DAP was 656±1190mGy-cm2. There was no significant difference in fluoroscopy time or dose between first-time and repeat injections (P=.405; P=.011) and no significant differences in fluoroscopy time or radiation dose when a trainee was involved (P=.756 for time and P=.149 for dose). Needle lengths of 1.5, 2.5, or 3.5in. were used during the injection, and there was no significant difference in needle length selection between BMI groups (P=.319).
  
  
  CONCLUSIONS
  Intra-articular glenohumeral joint injection fluoroscopy time and radiation dose are not affected by body mass index, age, gender, trainee-involvement, first versus repeat injection, or needle length. This procedure is associated with a dose of radiation that likely has minimal to no clinical significance.
authors.affiliation: Stanford University, Department of Orthopaedic Surgery, Division of PM&R, United States. Electronic address: rmattie@stanford.edu.
authors.forename: Ryan
authors.initials: R
authors.lastname: Mattie
authors.affiliation: University of California at San Francisco, Department of Orthopaedic Surgery, United States.
authors.forename: Zachary L
authors.initials: ZL
authors.lastname: McCormick
authors.affiliation: University of Utah School of Medicine, United States.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Fogg
authors.affiliation: University of Utah, Division of PM&R, Sports Medicine, United States.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Cushman
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D005260:Female; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D007270:Injections, Intra-Articular / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D012189:Retrospective Studies; D012785:Shoulder Joint / Q000000981:diagnostic imaging*; D013997:Time Factors
keywords: Fluoroscopy; Glenohumeral joint; Injection; Radiation; Shoulder