title: Local distribution of mepivacaine after distal interphalangeal joint injection in horses.
abstract: OBJECTIVE
  To evaluate the distribution of mepivacaine hydrochloride after distal interphalangeal (DIP) joint injection in horses.
  
  
  METHODS
  Prospective, uncontrolled study.
  
  
  METHODS
  10 adult horses.
  
  
  METHODS
  30 minutes before euthanasia, 8 ml of 2% mepivacaine hydrochloride was injected into the dorsal pouch of a forelimb DIP joint. Synovial tissue from the DIP joint and podotrochlear (navicular) bursa and bone tissue from the medullary cavity of the distal sesamoid (navicular) bone were taken from both forelimbs immediately after death. All synovial and bone specimens were analyzed for tissue concentration of mepivacaine by high-performance liquid chromatography. Synovial tissue and bone specimen concentrations from the injected forelimb were compared with corresponding specimens from the noninjected forelimb. All synovial tissue and bone specimen concentrations were compared with an estimated effective tissue concentration of mepivacaine (0.3 microgram/mg) for local anesthesia.
  
  
  RESULTS
  Specimen concentrations of mepivacaine from the injected forelimb were significantly greater (P < 0.05) than those in the corresponding tissues of the contralateral noninjected forelimb. All DIP joint and navicular bursa synovial tissue specimens from the injected forelimb had greater than the estimated effective tissue concentration of mepivacaine for local anesthesia. Of the 10 navicular bone specimens from the injected forelimb, 4 were higher and 2 were within 20% of the estimated effective tissue concentration of mepivacaine for local anesthesia.
  
  
  CONCLUSIONS
  Mepivacaine hydrochloride deposited into the DIP joint should anesthetize pain arising from navicular bursa synovia and may decrease pain arising from the medullary cavity of the navicular bone.
  
  
  CONCLUSIONS
  DIP joint injection of mepivacaine hydrochloride is not specific for DIP joint pain.
authors.affiliation: Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia 65211, USA.
authors.forename: K G
authors.initials: KG
authors.lastname: Keegan
authors.forename: D A
authors.initials: DA
authors.lastname: Wilson
authors.forename: J M
authors.initials: JM
authors.lastname: Kreeger
authors.forename: M R
authors.initials: MR
authors.lastname: Ellersieck
authors.forename: K C
authors.initials: KC
authors.lastname: Kuo
authors.forename: Z
authors.initials: Z
authors.lastname: Li
mesh_terms: D000818:Animals; D005260:Female; D005552:Forelimb; D006734:Horse Diseases; D006736:Horses; D007267:Injections; D008297:Male; D008619:Mepivacaine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D009069:Movement Disorders / Q000503:physiopathology / Q000662:veterinary; D011446:Prospective Studies; D014033:Toe Joint / Q000378:metabolism*
chemical_list: D008619:Mepivacaine