title: Duration of fluoroscopic-guided spine interventions and radiation exposure is increased in overweight patients.
abstract: BACKGROUND
  The impact of patient body mass index (BMI) on image-guided spine interventions remains unknown. Higher BMI is known to complicate the acquisition of radiographic images. Therefore it can be hypothesized that the patient's body habitus can influence the delivery of a spinal injection.
  
  
  OBJECTIVE
  To quantify the impact of patient BMI on the length of fluoroscopy and procedure times during spine interventions.
  
  
  METHODS
  Secondary analysis of 2 prospective observational studies.
  
  
  METHODS
  All injections were performed in an outpatient university setting.
  
  
  METHODS
  A total of 209 patients in whom spine injections were performed (99 women), with a mean age of 54.6 years.
  
  
  METHODS
  The fluoroscopy times for 202 participants and total procedure times for 137 participants were recorded. Additional participant characteristics, including age, gender, BMI, and actual procedures performed, also were collected. Analysis of covariance and linear and nonlinear model analysis were performed to assess the effect of BMI on fluoroscopy and procedure times.
  
  
  METHODS
  Fluoroscopy time and procedure duration times.
  
  
  RESULTS
  Participants had a mean age of 54.6 years, 51% were men, and 77% (n = 155) were overweight (BMI ≥25). Participants received the following interventions: 40 zygapophyseal joint injections, 33 medial branch nerve blocks, 113 transforaminal epidural injections, and 16 combined zygapophyseal joint injections and epidural injections. Gender, procedure number, and procedure type did not differ between groups. The overweight group demonstrated a 30% increase in mean fluoroscopy time and a 35% increase in mean procedure time. Controlling for other variables, we found that differences in fluoroscopy time and procedure time were significant (P = .032 and P = .031, respectively) between the 2 groups.
  
  
  CONCLUSIONS
  Significantly prolonged procedure time and fluoroscopy time in overweight patients increase the risks associated with spine interventions, not only to the patients but also to the operating room staff exposed to ionizing radiation.
authors: Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA. msmuck@stanford.edu
authors: Matthew
authors: M
authors: Smuck
authors: Patricia
authors: P
authors: Zheng
authors: Timothy
authors: T
authors: Chong
authors: Ming-Chih
authors: MC
authors: Kao
authors: Michael E
authors: ME
authors: Geisser
mesh_terms: D005471:Fluoroscopy / Q000379:methods*; D005500:Follow-Up Studies; D006801:Humans; D007278:Injections, Spinal / Q000379:methods; D017116:Low Back Pain / Q000150:complications / Q000000981:diagnostic imaging / Q000628:therapy*; D008297:Male; D050177:Overweight / Q000150:complications* / Q000000981:diagnostic imaging; D011446:Prospective Studies; D011829:Radiation Dosage; D015641:Radiography, Interventional / Q000379:methods*; D013997:Time Factors