title: Injuries of the calcaneal insertions of the superficial digital flexor tendon in 19 horses.
abstract: BACKGROUND
  Injuries of the calcaneal insertions of the superficial digital flexor tendon and their relationship to displacement of the tendon from the calcaneus have not previously been reported.
  
  
  OBJECTIVE
  To describe findings made on clinical cases with disruption of the calcaneal insertions of the superficial digital flexor tendon (SDFT) including observations on their role in horses with unstable subluxation of the tendon. To describe novel surgical techniques and the results of treatment.
  
  
  OBJECTIVE
  Disruption of the calcaneal insertions of the SDFT is associated with lameness and distension of the calcaneal bursa. Unstable displacement of the SDFT from the calcaneus is a more complex injury than incomplete disruption of one of its calcaneal insertions.
  
  
  METHODS
  The case records and diagnostic images of horses with lesions involving the calcaneal insertions of the SDFT, which were confirmed by endoscopic evaluation of calcaneal bursa between 2005 and 2009, were reviewed.
  
  
  RESULTS
  Nineteen horses were identified including 7 that had unstable displacement of the tendon from the calcaneus. Following endoscopic surgery, 9 of 12 horses with stable tendons and 6 of 7 horses with unstable displaced SDFTs returned to work.
  
  
  CONCLUSIONS
  Tearing of the calcaneal insertions of the SDFT is associated with lameness and distension of the calcaneal bursa; endoscopic removal of the torn tissue carries a good prognosis. Horses with unstable displacement of the tendon have also disruption of the tendon fibrocartilage cap. Removal of this results in stable subluxation and can return horses to athletic activity. Both lesions can be detected by preoperative ultrasonography.
  
  
  CONCLUSIONS
  Tearing of the calcaneal insertions of the SDFT should be included in the differential diagnoses of lame horses with distended calcaneal bursae. Tearing of the tendon fibrocartilage cap in horses with unstable displacement of the SDFT is a plausible explanation of the clinical features of the injury and explains previously unreliable results of reconstructive surgeries. Subtotal resection is a technically demanding technique but appears to offer an improved prognosis.
authors.affiliation: Newmarket Equine Hospital, Cambridge Road, Newmarket, Suffolk, UK. referrals@neh.uk.com
authors.forename: I M
authors.initials: IM
authors.lastname: Wright
authors.forename: G J
authors.initials: GJ
authors.lastname: Minshall
mesh_terms: D000818:Animals; D005260:Female; D005552:Forelimb; D006734:Horse Diseases / Q000473:pathology* / Q000601:surgery; D006736:Horses / Q000293:injuries*; D008297:Male; D012189:Retrospective Studies; D013708:Tendon Injuries / Q000473:pathology / Q000601:surgery / Q000662:veterinary*