title: Tibial nerve decompression in patients with tarsal tunnel syndrome: pressures in the tarsal, medial plantar, and lateral plantar tunnels.
abstract: BACKGROUND
  The anatomical basis for the surgical techniques used to treat tarsal tunnel syndrome is not well studied. The authors sought to evaluate their hypotheses that (1) pronation and pronation with plantar flexion of the intact foot would have higher pressures than the intact foot in other positions; (2) decompression surgery would significantly lower the pressure in all three tunnels in all foot positions, and roof incision plus septum excision would lower the pressure further in some positions; and (3) the pressures in symptomatic patients would be significantly higher than those in an analogous cadaver study.
  
  
  METHODS
  In 10 patients with tarsal tunnel syndrome, the authors intraoperatively measured pressures in the tarsal, medial plantar, and lateral plantar tunnels in multiple foot positions before and after excision of the tunnel roofs and intertunnel septum.
  
  
  RESULTS
  The authors found that (1) pronation and plantar flexion significantly increased pressures in the medial and lateral plantar tunnels, to levels sufficient to cause chronic nerve compression; (2) tunnel release and septum excision significantly decreased those pressures; and (3) compared with cadaver pressures, patients had similar tarsal tunnel pressures but higher lateral plantar tunnel pressures in some positions.
  
  
  CONCLUSIONS
  Many surgeons operating on patients with tarsal tunnel syndrome do not decompress the respective medial plantar and lateral plantar nerves and excise the septum. The authors' study validates the hypotheses that patients who are clinically suspected of having chronic compression of the tibial nerve and its branches at the ankle have higher tunnel pressures and that releasing these structures decreases the pressures.
authors.affiliation: Baltimore, Md. From the Division of Plastic, Reconstructive, and Maxillofacial Surgery, Department of Surgery, The Johns Hopkins University, and the Dellon Institute for Peripheral Nerve Surgery.
authors.forename: Gedge D
authors.initials: GD
authors.lastname: Rosson
authors.forename: Allison R
authors.initials: AR
authors.lastname: Larson
authors.forename: Eric H
authors.initials: EH
authors.lastname: Williams
authors.forename: A Lee
authors.initials: AL
authors.lastname: Dellon
mesh_terms: D000328:Adult; D000368:Aged; D002102:Cadaver; D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D011187:Posture; D011312:Pressure; D011446:Prospective Studies; D013641:Tarsal Tunnel Syndrome / Q000601:surgery*; D013979:Tibial Nerve