title: An atraumatic case of extensive Achilles tendon ossification.
abstract: BACKGROUND
  Ossification of the Achilles tendon is rare with most cases of ossification or calcification consisting of small, focal lesions. This pathology is usually predisposed by surgery, trauma, or other factors.
  
  
  METHODS
  A case of extensive Achilles ossification and calcification, without prior surgery or trauma, is reported. Following removal of one of the largest ossific masses reported in the literature, measuring 11.0cm×2.5cm×2.0cm with additional 6.5cm calcifications, surgical reconstruction was required.
  
  
  CONCLUSIONS
  The objective of this report was to describe an unusual case of Achilles tendon ossification and calcification that occurred without the presence of predisposing factors. When a large gap is present after removal of the ossification, direct repair may be impossible and V-Y lengthening plus flexor hallucis longus (FHL) transfer is a viable option for pain relief and return to function.
authors.affiliation: Hospital for Special Surgery, East River Professional Building, 523 East 72nd Street, Suite 507, New York, NY 10021, USA. Electronic address: RossK@hss.edu.
authors.forename: Keir A
authors.initials: KA
authors.lastname: Ross
authors.affiliation: Hospital for Special Surgery, East River Professional Building, 523 East 72nd Street, Suite 507, New York, NY 10021, USA. Electronic address: SmythN@hss.edu.
authors.forename: Niall A
authors.initials: NA
authors.lastname: Smyth
authors.affiliation: Hospital for Special Surgery, East River Professional Building, 523 East 72nd Street, Suite 507, New York, NY 10021, USA. Electronic address: HannonC@hss.edu.
authors.forename: Charles P
authors.initials: CP
authors.lastname: Hannon
authors.affiliation: Hospital for Special Surgery, East River Professional Building, 523 East 72nd Street, Suite 507, New York, NY 10021, USA. Electronic address: SeaworthC@gmail.com.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Seaworth
authors.affiliation: Hospital for Special Surgery, East River Professional Building, 523 East 72nd Street, Suite 507, New York, NY 10021, USA. Electronic address: DiCarloE@hss.edu.
authors.forename: Edward F
authors.initials: EF
authors.lastname: DiCarlo
authors.affiliation: Hospital for Special Surgery, East River Professional Building, 523 East 72nd Street, Suite 507, New York, NY 10021, USA. Electronic address: KennedyJ@hss.edu.
authors.forename: John G
authors.initials: JG
authors.lastname: Kennedy
mesh_terms: D000125:Achilles Tendon / Q000473:pathology* / Q000601:surgery*; D016026:Bone Marrow Transplantation; D004487:Edema / Q000209:etiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000175:diagnosis* / Q000601:surgery*; D010146:Pain / Q000209:etiology; D053657:Platelet-Rich Plasma; D013709:Tendon Transfer
keywords: Achilles tendon; Heterotopic; Magnetic resonance imaging; Ossification; Pathologic calcification