title: Equine ulnar fracture repair with locking compression plates can be associated with inadvertent penetration of the lateral cortex of the radius.
abstract: OBJECTIVE
  To evaluate if the use of locking head screws (LHS) in the distal holes of a locking compression plate (LCP) applied to the caudal aspect of the ulna to treat equine ulnar fractures is associated with a risk of injury to the lateral cortex of the radius.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Cadaveric equine forelimbs (n = 8 pair).
  
  
  METHODS
  After transverse ulnar osteotomy, osteosynthesis was performed with a narrow 10-13 hole 4.5/5.0 LCP applied to the caudal aspect of each ulna. The distal 3 holes were filled with 4.5 mm cortex screws (CS) in 1 limb (group 1) and with 5.0 mm LHS contralaterally (group 2). CS were inserted in an angle deemed appropriate by the surgeon and LHS were inserted perpendicular to the plate. Implant position and injury to the lateral cortex of the radius were assessed by radiography, CT, and limb dissection.
  
  
  RESULTS
  In group 1, injury of the lateral radius cortex did not occur. In group 2, 4 limbs and 6/24 LHS were associated with injury of the lateral radius cortex by penetration of a LHS. This difference was statistically significant. CS were inserted with a mean angle of 17.6° from the sagittal plane in a caudolateral-craniomedial direction.
  
  
  CONCLUSIONS
  Use of LHS in the distal part of a LCP applied to the caudal aspect of the ulna is associated with a risk of inadvertent injury to the lateral cortex of the radius.
authors.affiliation: Equine Hospital, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
authors.forename: Jan M
authors.initials: JM
authors.lastname: Kuemmerle
authors.forename: Karolin
authors.initials: K
authors.lastname: Kühn
authors.forename: Marco
authors.initials: M
authors.lastname: Bryner
authors.forename: Anton E
authors.initials: AE
authors.lastname: Fürst
mesh_terms: D000818:Animals; D001860:Bone Plates / Q000009:adverse effects / Q000662:veterinary*; D002102:Cadaver; D005260:Female; D005552:Forelimb; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000662:veterinary*; D050723:Fractures, Bone / Q000601:surgery*; D006736:Horses; D008297:Male