title: An unusual cause of ankle pain: fracture of a talocalcaneal coalition as a differential diagnosis in an acute ankle sprain: a case report and literature review.
abstract: BACKGROUND
  The acute ankle sprain is one of the most common injuries seen in trauma departments. Ankle sprains have an incidence of about one injury per 10 000 people a day. In contrast tarsal coalition is a rare condition occurring in not more than one percent of the population.
  
  
  METHODS
  We present the case of a 23 year old male patient with pain and local swelling after an acute ankle sprain. Initial clinical and radiological examination showed no pathologies. Due to prolonged pain, swelling and the inability of the patient to weight bear one week after trauma further diagnostics was performed. Imaging studies (MRI and CT) revealed a fracture of a talocalcaneal coalition. To the knowledge of the authors no fracture of a coalition was reported so far.
  
  
  CONCLUSIONS
  This report highlights the presentation of symptomatic coalitions following trauma and furthermore, it points out the difficulties in the diagnosis and treatment of a rare entity after a common injury. A diagnostic algorithm has been developed to ensure not to miss a severe injury.
authors.affiliation: Department of Trauma, Hand and Reconstructive Surgery, University Hospital Münster, Albert-Schweitzer-Campus 1, Building W1, 48149 Münster, Germany. dirk.waehnert@ukmuenster.de
authors.forename: Dirk
authors.initials: D
authors.lastname: Wähnert
authors.forename: Niklas
authors.initials: N
authors.lastname: Grüneweller
authors.forename: Julia
authors.initials: J
authors.lastname: Evers
authors.forename: Anna C
authors.initials: AC
authors.lastname: Sellmeier
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Raschke
authors.forename: Sabine
authors.initials: S
authors.lastname: Ochman
mesh_terms: D016512:Ankle Injuries / Q000150:complications / Q000175:diagnosis*; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D010146:Pain / Q000175:diagnosis* / Q000209:etiology; D013180:Sprains and Strains / Q000150:complications / Q000175:diagnosis*; D013380:Subtalar Joint / Q000293:injuries* / Q000473:pathology; D055815:Young Adult