title: Radiation dose and intra-articular access: comparison of the lateral mortise and anterior midline approaches to fluoroscopically guided tibiotalar joint injections.
abstract: OBJECTIVE
  To compare the lateral mortise and anterior midline approaches to fluoroscopically guided tibiotalar joint injections with respect to successful intra-articular needle placement, fluoroscopy time, radiation dose, and dose area product (DAP).
  
  
  METHODS
  This retrospective study was IRB-approved and HIPAA-compliant. 498 fluoroscopically guided tibiotalar joint injections were performed or supervised by one of nine staff radiologists from 11/1/2010-12/31/2013. The injection approach was determined by operator preference. Images were reviewed on a PACS workstation to determine the injection approach (lateral mortise versus anterior midline) and to confirm intra-articular needle placement. Fluoroscopy time (minutes), radiation dose (mGy), and DAP (μGy-m(2)) were recorded and compared using the student's t-test (fluoroscopy time) or the Wilcoxon rank sum test (radiation dose and DAP).
  
  
  RESULTS
  There were 246 lateral mortise injections and 252 anterior midline injections. Two lateral mortise injections were excluded from further analysis because no contrast was administered. Intra-articular location of the needle tip was documented in 242/244 lateral mortise injections and 252/252 anterior midline injections. Mean fluoroscopy time was shorter for the lateral mortise group than the anterior midline group (0.7 ± 0.5 min versus 1.2 ± 0.8 min, P < 0.0001). Mean radiation dose and DAP were less for the lateral mortise group than the anterior midline group (2.1 ± 3.7 mGy versus 2.5 ± 3.5 mGy, P = 0.04; 11.5 ± 15.3 μGy-m(2) versus 13.5 ± 17.3 μGy-m(2), P = 0.006).
  
  
  CONCLUSIONS
  Both injection approaches resulted in nearly 100% rates of intra-articular needle placement, but the lateral mortise approach used approximately 40% less fluoroscopy time and delivered 15% lower radiation dose and DAP to the patient.
authors.affiliation: Department of Radiology, Division of Musculoskeletal Imaging and Intervention, Massachusetts General Hospital, 55 Fruit Street, Yawkey 6E, Boston, MA, 02114, USA. ajhuang@mgh.harvard.edu.
authors.forename: Ambrose J
authors.initials: AJ
authors.lastname: Huang
authors.affiliation: Department of Radiology, Centro Medico de Occidente, Maracaibo, Venezuela. renebalza@gmail.com.
authors.forename: Rene
authors.initials: R
authors.lastname: Balza
authors.affiliation: Department of Radiology, Division of Musculoskeletal Imaging and Intervention, Massachusetts General Hospital, 55 Fruit Street, Yawkey 6E, Boston, MA, 02114, USA. mtorriani@mgh.harvard.edu.
authors.forename: Martin
authors.initials: M
authors.lastname: Torriani
authors.affiliation: Department of Radiology, Division of Musculoskeletal Imaging and Intervention, Massachusetts General Hospital, 55 Fruit Street, Yawkey 6E, Boston, MA, 02114, USA. mbredella@mgh.harvard.edu.
authors.forename: Miriam A
authors.initials: MA
authors.lastname: Bredella
authors.affiliation: Department of Radiology, Division of Musculoskeletal Imaging and Intervention, Massachusetts General Hospital, 55 Fruit Street, Yawkey 6E, Boston, MA, 02114, USA. cychang@mgh.harvard.edu.
authors.forename: Connie Y
authors.initials: CY
authors.lastname: Chang
authors.affiliation: Department of Radiology, Division of Musculoskeletal Imaging and Intervention, Massachusetts General Hospital, 55 Fruit Street, Yawkey 6E, Boston, MA, 02114, USA. fsimeone@mgh.harvard.edu.
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Simeone
authors.affiliation: Department of Radiology, Division of Musculoskeletal Imaging and Intervention, Massachusetts General Hospital, 55 Fruit Street, Yawkey 6E, Boston, MA, 02114, USA. wpalmer@mgh.harvard.edu.
authors.forename: William E
authors.initials: WE
authors.lastname: Palmer
mesh_terms: D000777:Anesthetics / Q000008:administration & dosage; D018771:Arthralgia / Q000000981:diagnostic imaging / Q000188:drug therapy*; D001175:Arthrography / Q000379:methods; D005260:Female; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D007270:Injections, Intra-Articular / Q000379:methods*; D015552:Injections, Intralesional / Q000379:methods; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000032:analysis* / Q000517:prevention & control; D011835:Radiation Protection / Q000379:methods; D015641:Radiography, Interventional / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013640:Tarsal Joints / Q000000981:diagnostic imaging*
chemical_list: D000777:Anesthetics
keywords: Ankle; Fluoroscopy; Injection; Radiation dose; Tibiotalar joint