title: Sonographically guided posterior subtalar joint injections via the sinus tarsi approach.
abstract: OBJECTIVE
  To determine the feasibility and accuracy of sonographically guided posterior subtalar joint (PSTJ) injections performed through the sinus tarsi.
  
  
  METHODS
  A single experienced operator completed 10 sonographically guided PSTJ injections via the sinus tarsi on 10 unembalmed cadaveric ankle-foot specimens. Injections were performed using a 17-5-MHz linear transducer, a 25-gauge, 50-mm needle, and an out-of-plane, anterior-to-posterior needle trajectory parallel to the calcaneal surface. Sonographic assessment for fluid in the posterior and lateral PSTJ recesses, sinus tarsi, and peroneal tendon sheath was performed before and after injections of 2 and 4 mL of tap water. Two additional specimens were injected with a contrast agent: 1 via the sonographically guided approach and another by a computed tomographically guided approach.
  
  
  RESULTS
  All 10 sonographically guided PSTJ tap water injections were accurate, distending both the posterior and lateral PSTJ recesses. In addition, all 10 specimens showed posterior recess distension by 2 mL, whereas only 2 specimens (20%) showed lateral recess distension at this volume. By 4 mL, both recesses were clearly distended in all specimens. Both contrast agent injections produced similar PSTJ computed tomographic arthrograms and patterns of recess distension similar to the sonographically guided tap water injections. No sonographically guided PSTJ injection placed fluid in the peroneal tendon sheath.
  
  
  CONCLUSIONS
  Sonographically guided PSTJ injections via the sinus tarsi can accurately and specifically deliver injectate into the PSTJ while monitoring injectate flow within the posterior recess. The sinus tarsi approach may be used as an alternative technique to perform sonographically guided PSTJ injections when clinically appropriate.
authors.affiliation: Departments of Physical Medicine and Rehabilitation (J.S.), Radiology (J.S., N.S.M.), and Anatomy (J.S.), Mayo Clinic College of Medicine, Rochester, Minnesota USA; Department of Physical Medicine and Rehabilitation, McMaster University, Hamilton, Ontario, Canada (E.M.); Division of Rheumatology, Boston University School of Medicine, Boston, Massachusetts USA (E.Y.K.); and Department of Radiology, University of Michigan, Ann Arbor, Michigan USA (J.A.J.). smith.jay@mayo.edu.
authors.forename: Jay
authors.initials: J
authors.lastname: Smith
authors.affiliation: Departments of Physical Medicine and Rehabilitation (J.S.), Radiology (J.S., N.S.M.), and Anatomy (J.S.), Mayo Clinic College of Medicine, Rochester, Minnesota USA; Department of Physical Medicine and Rehabilitation, McMaster University, Hamilton, Ontario, Canada (E.M.); Division of Rheumatology, Boston University School of Medicine, Boston, Massachusetts USA (E.Y.K.); and Department of Radiology, University of Michigan, Ann Arbor, Michigan USA (J.A.J.).
authors.forename: Eugene
authors.initials: E
authors.lastname: Maida
authors.affiliation: Departments of Physical Medicine and Rehabilitation (J.S.), Radiology (J.S., N.S.M.), and Anatomy (J.S.), Mayo Clinic College of Medicine, Rochester, Minnesota USA; Department of Physical Medicine and Rehabilitation, McMaster University, Hamilton, Ontario, Canada (E.M.); Division of Rheumatology, Boston University School of Medicine, Boston, Massachusetts USA (E.Y.K.); and Department of Radiology, University of Michigan, Ann Arbor, Michigan USA (J.A.J.).
authors.forename: Naveen S
authors.initials: NS
authors.lastname: Murthy
authors.affiliation: Departments of Physical Medicine and Rehabilitation (J.S.), Radiology (J.S., N.S.M.), and Anatomy (J.S.), Mayo Clinic College of Medicine, Rochester, Minnesota USA; Department of Physical Medicine and Rehabilitation, McMaster University, Hamilton, Ontario, Canada (E.M.); Division of Rheumatology, Boston University School of Medicine, Boston, Massachusetts USA (E.Y.K.); and Department of Radiology, University of Michigan, Ann Arbor, Michigan USA (J.A.J.).
authors.forename: Eugene Y
authors.initials: EY
authors.lastname: Kissin
authors.affiliation: Departments of Physical Medicine and Rehabilitation (J.S.), Radiology (J.S., N.S.M.), and Anatomy (J.S.), Mayo Clinic College of Medicine, Rochester, Minnesota USA; Department of Physical Medicine and Rehabilitation, McMaster University, Hamilton, Ontario, Canada (E.M.); Division of Rheumatology, Boston University School of Medicine, Boston, Massachusetts USA (E.Y.K.); and Department of Radiology, University of Michigan, Ann Arbor, Michigan USA (J.A.J.).
authors.forename: Jon A
authors.initials: JA
authors.lastname: Jacobson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007270:Injections, Intra-Articular; D008297:Male; D015203:Reproducibility of Results; D013380:Subtalar Joint / Q000000981:diagnostic imaging*; D018084:Ultrasonography, Interventional
chemical_list: D003287:Contrast Media
keywords: ankle; injection; musculoskeletal ultrasound; sinus tarsi; sonography; subtalar