title: Tarsal tunnel disease and talocalcaneal coalition: MRI features.
abstract: OBJECTIVE
  To assess, utilizing MRI, tarsal tunnel disease in patients with talocalcaneal coalitions. To the best of our knowledge, this has only anecdotally been described before.
  
  
  METHODS
  Sixty-seven ankle MRIs with talocalcaneal coalition were retrospectively reviewed for disease of tendons and nerves of the tarsal tunnel. Interobserver variability in diagnosing tendon disease was performed in 30 of the 67 cases. Tarsal tunnel nerves were also evaluated in a control group of 20 consecutive ankle MRIs.
  
  
  RESULTS
  Entrapment of the flexor hallucis longus tendon (FHL) by osseous excrescences was seen in 14 of 67 cases (21 %). Attenuation, split tearing, tenosynovitis, or tendinosis of the FHL was present in 26 cases (39 %). Attenuation or tenosynovitis was seen in the flexor digitorum longus tendon (FDL) in 18 cases (27 %). Tenosynovitis or split tearing of the posterior tibial tendon (PT) was present in nine cases (13 %). Interobserver variability ranged from 100 % to slight depending on the tendon and type of disease. Intense increased signal and caliber of the medial plantar nerve (MPN), indicative of neuritis, was seen in 6 of the 67 cases (9 %). Mildly increased T2 signal of the MPN was seen in 15 (22 %) and in 14 (70 %) of the control group.
  
  
  CONCLUSIONS
  Talocalcaneal coalitions may be associated with tarsal tunnel soft tissue abnormalities affecting, in decreasing order, the FHL, FDL, and PT tendons, as well as the MPN. This information should be provided to the referring physician in order to guide treatment and improve post-surgical outcome.
authors: New York University Langone Medical Center, New York, NY, USA. erin.fitzgerald@nyumc.org.
authors: Erin FitzGerald
authors: EF
authors: Alaia
authors: New York University Langone Medical Center, New York, NY, USA.
authors: Zehava Sadka
authors: ZS
authors: Rosenberg
authors: New York University Langone Medical Center, New York, NY, USA.
authors: Jenny T
authors: JT
authors: Bencardino
authors: New York University Langone Medical Center, New York, NY, USA.
authors: Gina A
authors: GA
authors: Ciavarra
authors: New York University Langone Medical Center, New York, NY, USA.|Centro de Diagnóstico Dr. Enrique Rossi, Buenos Aires, Argentina.
authors: Ignacio
authors: I
authors: Rossi
authors: New York University Langone Medical Center, New York, NY, USA.
authors: Catherine N
authors: CN
authors: Petchprapa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D000070604:Tarsal Coalition / Q000000981:diagnostic imaging* / Q000473:pathology; D013641:Tarsal Tunnel Syndrome / Q000000981:diagnostic imaging* / Q000473:pathology; D055815:Young Adult
keywords: Ankle; MR imaging; Talocalcaneal coalition; Tarsal tunnel disease