title: Sonographic visualization of the first branch of the lateral plantar nerve (baxter nerve): technique and validation using perineural injections in a cadaveric model.
abstract: OBJECTIVE
  The primary purpose of this investigation was to document the ability of high-resolution sonography to accurately identify the first branch of the lateral plantar nerve (FBLPN) using sonographically guided perineural injections in an unembalmed cadaveric model.
  
  
  METHODS
  single experienced operator completed sonographically guided perineural FBLPN injections in 12 unembalmed cadaveric specimens (6 right and 6 left) obtained from 10 donors (5 male and 5 female) aged 47 to 95 years (mean, 71 years) with an average body mass index of 24.2 kg/m(2) (range, 17.2-31.6 kg/m(2)). All injections were completed using 22-gauge, 38-mm stainless steel needles to deliver 1 mL of 50% diluted colored latex adjacent to the FBLPN in the abductor hallucis-quadratus plantae (AH-QP) interval. Six injections were completed using a cart-based ultrasound (US) machine and a 17-5-MHz transducer, and 6 were completed using a portable US machine and a 12-3-MHz transducer. Nerve conspicuity was graded on a 4-point scale (1, poor; 4, excellent). After a minimum of 24 hours, study coinvestigators dissected each specimen to assess injectate placement.
  
  
  RESULTS
  All 12 injections accurately placed latex onto the FBLPN within the AH-QP interval, with 11 of 12 (91%) resulting in complete nerve coverage. Proximal latex overflow to the lateral plantar nerve occurred in 82% of cases (10 of 12). The average distance between the plantar fascia and injected latex was 1.2 cm (range, 1.0-1.75 cm). No vascular injury was seen in any specimen. The average nerve conspicuities were 3.7 (range, 3-4) using the cart-based US machine and 1.8 (range, 1-4) using the portable US machine.
  
  
  CONCLUSIONS
  Sonographic visualization of the FBLPN in the AH-QP interval is feasible and should be considered for diagnostic and therapeutic purposes in patients presenting with chronic or atypical heel pain syndromes. Further clinical experience should refine the role of FBLPN sonography and explore the utility of sonographically guided diagnostic and therapeutic FBLPN perineural injections.
authors: Department of Physical Medicine and Rehabilitation, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
authors: James C
authors: JC
authors: Presley
authors: Eugene
authors: E
authors: Maida
authors: Wojciech
authors: W
authors: Pawlina
authors: Naveen
authors: N
authors: Murthy
authors: Daniel B
authors: DB
authors: Ryssman
authors: Jay
authors: J
authors: Smith
mesh_terms: D000305:Adrenal Cortex Hormones / Q000008:administration & dosage; D000368:Aged; D000369:Aged, 80 and over; D000779:Anesthetics, Local / Q000008:administration & dosage; D002102:Cadaver; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007267:Injections / Q000379:methods; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000000981:diagnostic imaging* / Q000188:drug therapy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013979:Tibial Nerve / Q000000981:diagnostic imaging* / Q000187:drug effects; D020429:Tibial Neuropathy / Q000000981:diagnostic imaging* / Q000188:drug therapy; D018084:Ultrasonography, Interventional / Q000379:methods*
chemical_list: D000305:Adrenal Cortex Hormones; D000779:Anesthetics, Local; D003287:Contrast Media
keywords: Baxter nerve; first branch of the lateral plantar nerve; perineural injections