title: Medial humeral epicondylitis in cats.
abstract: OBJECTIVE
  To describe medial humeral epicondylitis in cats based on radiographic, anatomic, and histologic observations.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Feline cadavers (n = 60).
  
  
  METHODS
  Extended craniocaudal, and extended and flexed mediolateral radiographic projections were taken of both elbows of 60 consecutive European shorthair cats that died or were euthanatized. Elbows with new bone formation at the medial epicondyle were dissected and embedded in methyl-methacrylate (MMA). For comparison, both elbows of a cat with no radiographic changes were prepared in a similar manner. Sections of the MMA blocks were Giemsa stained and examined with light microscopy.
  
  
  RESULTS
  Bilateral new bone formation was identified radiographically at the medial aspect of the humeral epicondyle in 6 cats (10%). All of these cats had mineral deposition in the humeral head of the flexor carpi ulnaris muscle. Other findings were cartilage damage (n = 3 cats), an additional loose medial joint body (1), and tendinosis (3). The ulnar nerve was flattened and displaced caudally, and signs of chronic epineural fibrosis were present in 2 severely affected cats.
  
  
  CONCLUSIONS
  Ten percent of this feline population had radiographic evidence of medial humeral epicondylitis with chronic degeneration, mineralization, and metaplastic bone formation in damaged fibrillar matrix involving the origin of the humeral head of the flexor carpi ulnaris muscle. New bone formation caused displacement and compression of the ulnar nerve in severely affected elbows. Based on our findings, medial humeral epicondylitis appears to be a common disorder in cats with potential clinical sequelae.
authors.affiliation: Section of Small Animal Surgery, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland. rstreubel@vetclinics.uzh.ch
authors.forename: Ronny
authors.initials: R
authors.lastname: Streubel
authors.forename: Hans
authors.initials: H
authors.lastname: Geyer
authors.forename: Pierre M
authors.initials: PM
authors.lastname: Montavon
mesh_terms: D000818:Animals; D002102:Cadaver; D002371:Cat Diseases / Q000000981:diagnostic imaging* / Q000473:pathology*; D002415:Cats; D005552:Forelimb / Q000000981:diagnostic imaging* / Q000473:pathology*; D006811:Humerus / Q000000981:diagnostic imaging / Q000473:pathology*; D007592:Joint Diseases / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D007596:Joints / Q000473:pathology*; D011446:Prospective Studies; D011859:Radiography