title: Sonographic Visualization of the Posterior Cutaneous Nerve of the Forearm: Technique and Validation Using Perineural Injections in a Cadaveric Model.
abstract: OBJECTIVE
  To determine the ability to sonographically identify the posterior cutaneous nerve of the forearm (PCNF) and its distal epicondylar branches using sonographically guided perineural injections in an unembalmed cadaveric model.
  
  
  METHODS
  A single experienced operator used a 12-3-MHz linear array transducer to identify the PCNF and its distal epicondylar region branches in 10 unembalmed cadaveric specimens (6 right and 4 left) obtained from 10 donors. Sonographically guided perineural PCNF injections were then completed with a 22-gauge, 38-mm stainless steel needle to deliver 0.25 mL of 50% diluted colored latex at 3 points along the PCNF. The latex location was then confirmed via dissection.
  
  
  RESULTS
  The 10 donors included 4 male and 6 female cadavers aged 48 to 94 years (mean, 73 years) with body mass indices of 19 to 37 kg/m2(mean, 26 kg/m2). The operator sonographically identified the PCNF and several distal branches traversing over or directly adjacent to the lateral epicondyle in all 10 specimens. Only 7 of 10 specimens showed a distinct PCNF bifurcation into anterior and posterior divisions, and all 7 were accurately identified and localized on sonography. There was no evidence of latex overflow to clinically relevant adjacent structures or injury to regional vessels or nerves.
  
  
  CONCLUSIONS
  High-resolution sonography can identify the PCNF and its distal epicondylar branches. Sonographic evaluation of the PCNF should be included in the evaluation of patients presenting with refractory or atypical lateral elbow pain syndromes. Diagnostic and therapeutic sonographically guided procedures targeting the PCNF or its lateral epicondylar branches are feasible and warrant further investigation.
authors.affiliation: Departments of Physical Medicine and Rehabilitation, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Eugene
authors.initials: E
authors.lastname: Maida
authors.affiliation: Department of Radiology, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Mary M
authors.initials: MM
authors.lastname: Chiavaras
authors.affiliation: Departments of Physical Medicine and Rehabilitation, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: Elena J
authors.initials: EJ
authors.lastname: Jelsing
authors.affiliation: Department of Orthopedics, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: Shawn W
authors.initials: SW
authors.lastname: O'Driscoll
authors.affiliation: Department of Anatomy, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Pawlina
authors.affiliation: Departments of Physical Medicine and Rehabilitation, Radiology, and Anatomy, Mayo Clinic College of Medicine, Mayo Clinic Sports Medicine Center, Rochester, Minnesota, USA.
authors.forename: Jay
authors.initials: J
authors.lastname: Smith
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D005260:Female; D005542:Forearm / Q000000981:diagnostic imaging* / Q000294:innervation*; D006801:Humans; D007270:Injections, Intra-Articular; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D018084:Ultrasonography, Interventional / Q000379:methods*
keywords: elbow; forearm; lateral epicondylitis; musculoskeletal ultrasound; posterior antebrachial cutaneous nerve; posterior cutaneous nerve; sonographic visualization