title: Evaluation of a proximal block site and the use of nerve-stimulator-guided needle placement for posterior tibial nerve block.
abstract: BACKGROUND
  Posterior tibial nerve (PTN) block has traditionally been performed in the para-medial malleolar area without nerve stimulator (NS) guidance. The PTN can also be blocked proximally (7 cm) above the medial malleolus in the subfascial plane between the flexor hallucis longus and flexor digitorum longus tendons. In this study we compared the frequency of successful PTN block at the traditional distal (D) site (2 cm above the medial malleolus) with and without NS guidance. We also compared block success and latency at the D site versus the proximal (P) block site.
  
  
  METHODS
  Subjects were randomized to P-NS (n = 45), D-NS (n = 45), or D without NS (n = 45). Levobupivacaine 0.625%, 0.15 mL/kg was used for all blocks. Pinprick sensory anesthesia was evaluated in the distribution of the medial plantar, lateral plantar, and medial calcaneal nerves. PTN block was considered successful if surgical anesthesia was achieved in all PTN distributions.
  
  
  RESULTS
  The frequency of successful PTN block was greater for D-NS (100%) and P-NS (93.5%), compared with D (73.3%) (P = 0.02). Median latency to complete block was less for D-NS (8 min, 95% CI 7-9 min) than D (20 min, 95% CI 13-26 min) (P < 0.01) and P-NS (15 min, 95% CI 12-18 min) (P = 0.04).
  
  
  CONCLUSIONS
  NS-guided needle placement improves the success and decreases the latency to onset of complete PTN block at the D site. The P approach to PTN block may be a useful alternative to the traditional D site approach, particularly in patients with restricted access to the D site.
authors.affiliation: Department of Anesthesiology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA. r-dotyjr@northwestern.edu
authors.forename: Robert
authors.initials: R
authors.lastname: Doty
authors.forename: Radha
authors.initials: R
authors.lastname: Sukhani
authors.forename: Mark C
authors.initials: MC
authors.lastname: Kendall
authors.forename: Edward
authors.initials: E
authors.lastname: Yaghmour
authors.forename: Antoun
authors.initials: A
authors.lastname: Nader
authors.forename: Alina
authors.initials: A
authors.lastname: Brodskaia
authors.forename: Tripti C
authors.initials: TC
authors.lastname: Kataria
authors.forename: Robert
authors.initials: R
authors.lastname: McCarthy
mesh_terms: D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000494:pharmacology; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009339:Needles; D009407:Nerve Block / Q000295:instrumentation* / Q000379:methods*; D011446:Prospective Studies; D016037:Single-Blind Method; D013979:Tibial Nerve / Q000187:drug effects / Q000502:physiology
chemical_list: D000779:Anesthetics, Local