title: Bilateral posterior tarsal tunnel syndrome caused by accessory flexor digitorum longus; case report and surgical technique.
abstract: OBJECTIVE
  To present a case report of bilateral posterior tarsal tunnel syndrome (PTTS) caused by an accessory flexor digitorum longus (AFDL), including the surgical technique and a review of the literature.
  
  
  METHODS
  Twenty-nine year old male diagnosed with bilateral PTTS, refractory to conservative management, with 53 points on the preoperative AOFAS score. MR of both ankles showed an AFDL within the tarsal tunnel, in close relationship to the posterior tibial nerve. Bilateral tarsal tunnel decompression and AFDL resection was performed.
  
  
  RESULTS
  There were no post-operative complications. At 6 months after surgery, the patient had no pain and had 87 points on the AOFAS score.
  
  
  CONCLUSIONS
  The PTTS is an entrapment neuropathy of the posterior tibial nerve or one of its terminal branches. A rare cause is the presence of an AFDL, and its resection is associated with good clinical results. Careful scar tissue resection and neurolysis is recommended. Knowing the normal pathway and anatomical variability of the posterior tibial nerve and its branches is essential to avoid iatrogenic injury. In our case report, MR and intraoperative findings identified a bilateral FDLA in close relationship to the common flexor digitorum, an unusual finding, with few reports in current literature.
  
  
  CONCLUSIONS
  Careful tarsal tunnel decompression and AFDL resection in our patient with bilateral symptomatic PTTS has good clinical results and no complications, particularly when diagnosed and treated early.
authors.affiliation: Ortopedia y Traumatología, Pontificia Universidad Católica de Chile, Santiago, Chile. Electronic address: andysh@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Schmidt-Hebbel
authors.affiliation: Cirugía de tobillo y pie, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: J
authors.initials: J
authors.lastname: Elgueta
authors.affiliation: Equipo de tobillo y pie, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: A
authors.initials: A
authors.lastname: Villa
authors.affiliation: Equipo de tobillo y pie, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: P
authors.initials: P
authors.lastname: Mery
authors.affiliation: Equipo de tobillo y pie, Pontificia Universidad Católica de Chile, Santiago, Chile.
authors.forename: J
authors.initials: J
authors.lastname: Filippi
mesh_terms: D000328:Adult; D019299:Decompression, Surgical / Q000379:methods*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000601:surgery; D019637:Orthopedic Procedures / Q000379:methods*; D013641:Tarsal Tunnel Syndrome / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*
keywords: Accessory flexor digitorum longus; Flexor digitorum longus accesorio; Resección quirúrgica; Surgical technique; Tarsal tunnel; Túnel del tarso