title: Effect of the Proximal Abducting Ulnar Osteotomy on Intra-Articular Pressure Distribution and Contact Mechanics of Congruent and Incongruent Canine Elbows Ex Vivo.
abstract: OBJECTIVE
  To determine the effects of the Proximal Abducting Ulnar Osteotomy (PAUL) on contact pressures of congruent and incongruent (short radius) canine elbows.
  
  
  METHODS
  Ex vivo biomechanical study.
  
  
  METHODS
  Unpaired normal cadaveric canine forelimbs (n=16).
  
  
  METHODS
  A servohydraulic testing frame and thin-film sensors were utilized to measure intra-articular contact area (CA), mean contact pressure (mCP), and peak contact pressure (pCP) for medial and lateral elbow compartments. Percent contribution of the medial compartment relative to the whole (%Med) was also examined. Baseline data were collected in 9 congruent elbows and 7 incongruent elbows where the radius was shortened. Both sets of elbows were tested following ulnar osteotomy and sequential placement of 2 and 3 mm PAUL plates and paw repositioning (to account for any medial to lateral shift of transarticular forces). Paired t-tests compared sequential procedural steps. P<.05 was significant.
  
  
  RESULTS
  For congruent elbows, the 2 mm PAUL plate decreased CA in both compartments compared to baseline; lateral pCP increased with subsequent paw repositioning. Induction of radio-ulnar incongruity decreased CA and increased mCP medially, decreased pCP laterally, and increased %MedCA and %MedmCP compared to baseline. Both PAUL plates decreased mCP and pCP medially, with no effect laterally. Paw repositioning had no effect.
  
  
  CONCLUSIONS
  The PAUL procedure had no effect on medial compartment pressure in the congruent elbow. It may ameliorate increased medial compartment pressure in the incongruent elbow. This change does not result from a medial to lateral compartmental shift and deserves further investigation.
authors.affiliation: Department of Clinical Sciences, Cornell University, Ithaca, New York.
authors.forename: Marina J
authors.initials: MJ
authors.lastname: McConkey
authors.affiliation: Department of Clinical Sciences, Cornell University, Ithaca, New York.
authors.forename: Dominick M
authors.initials: DM
authors.lastname: Valenzano
authors.affiliation: Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York.
authors.forename: Alexander
authors.initials: A
authors.lastname: Wei
authors.affiliation: Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York.
authors.forename: Ting
authors.initials: T
authors.lastname: Li
authors.affiliation: Department of Clinical Sciences, Cornell University, Ithaca, New York.
authors.forename: Margret S
authors.initials: MS
authors.lastname: Thompson
authors.affiliation: Department of Population Medicine, Cornell University, Ithaca, New York.
authors.forename: Hussni O
authors.initials: HO
authors.lastname: Mohammed
authors.affiliation: Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York.
authors.forename: Marjolein C H
authors.initials: MC
authors.lastname: van der Meulen
authors.affiliation: Department of Clinical Sciences, Cornell University, Ithaca, New York.
authors.forename: Ursula
authors.initials: U
authors.lastname: Krotscheck
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001860:Bone Plates / Q000662:veterinary*; D002102:Cadaver; D004283:Dog Diseases / Q000601:surgery*; D004285:Dogs / Q000502:physiology; D004551:Elbow Joint / Q000502:physiology*; D005552:Forelimb / Q000502:physiology; D010027:Osteotomy / Q000662:veterinary; D011312:Pressure; D016059:Range of Motion, Articular; D038062:Upper Extremity Deformities, Congenital / Q000601:surgery / Q000662:veterinary*