title: Use of magnetic resonance imaging for identifying subchondral bone damage in horses: 11 cases (1999-2003).
abstract: OBJECTIVE
  To assess the use of magnetic resonance (MR) imaging for identifying subchondral bone damage in the distal limbs of horses.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  11 horses.
  
  
  METHODS
  Medical records of horses with lameness and subsequent evidence of subchondral bone damage as determined by MR imaging were reviewed. Severity and duration of lameness, results of diagnostic local anesthesia and diagnostic testing, surgical and necropsy findings, and treatment were recorded. Outcome was determined by follow-up information obtained from the owner or referring veterinarian.
  
  
  RESULTS
  Lameness was localized by physical examination and diagnostic local anesthesia. Lameness was localized to the metacarpophalangeal or metatarsophalangeal joint in 4 horses, distal interphalangeal joint in 5 horses, and tarsocrural joint in 2 horses. The duration of lameness ranged from 2 weeks to 20 months. Magnetic resonance imaging of the affected joints revealed abnormal fluid accumulation within the subchondral bone. None of the abnormalities observed by MR imaging were detected by radiography. Subchondral bone damage was diagnosed in all horses. Arthroscopy of the affected joint was performed in 4 horses. Communication with the articular surface of the affected bone was suspected on the basis of results of MR imaging in 4 horses and was confirmed by arthroscopy in 1 horse and by necropsy in 1 horse.
  
  
  CONCLUSIONS
  Magnetic resonance imaging was useful for providing a diagnosis when other imaging techniques did not definitively identify the cause of lameness. Subchondral bone damage was clearly identified by MR imaging and should be considered as a cause of lameness in horses in which radiographic findings are unremarkable.
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA.
authors.forename: Chad J
authors.initials: CJ
authors.lastname: Zubrod
authors.forename: Robert K
authors.initials: RK
authors.lastname: Schneider
authors.forename: Russell L
authors.initials: RL
authors.lastname: Tucker
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Gavin
authors.forename: Claude A
authors.initials: CA
authors.lastname: Ragle
authors.forename: Kelly D
authors.initials: KD
authors.lastname: Farnsworth
mesh_terms: D000818:Animals; D001182:Arthroscopy / Q000662:veterinary; D001842:Bone and Bones / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D005552:Forelimb; D006614:Hindlimb; D006734:Horse Diseases / Q000175:diagnosis* / Q000473:pathology; D006736:Horses; D007596:Joints / Q000473:pathology*; D007794:Lameness, Animal / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000662:veterinary*; D008297:Male; D012189:Retrospective Studies