title: Comparison of osteotomy technique and jig type in completion of distal femoral osteotomies for correction of medial patellar luxation. An in vitro study.
abstract: OBJECTIVE
  Femoral osteotomies are frequently completed to correct malalignment associated with patellar luxation. The objectives of this study were to compare the use of: 1) two different types of jig; and 2) different types of osteotomy in the realignment of canine femoral bone models which possessed various iterations of angular deformity.
  
  
  METHODS
  Models of canine femora possessing distal varus, external torsion and a combination of varus and torsion underwent correction utilizing two alignment jigs (Slocum jig and Deformity Reduction Device) and either a closing wedge ostectomy (CWO) or an opening wedge osteotomy (OWO). Post-correctional alignment was evaluated by radiographic assessment and compared between groups.
  
  
  RESULTS
  The use of the Slocum jig resulted in frontal plane overcorrection when used with CWO in models of femoral varus, and when used with OWO in models of femoral varus and external torsion when compared to other techniques. The Deformity Reduction Device tended to realign the frontal plane closer to the post-correction target value in all angulation types. The use of both jigs resulted in undercorrection in the transverse plane in models with varus and torsion.
  
  
  CONCLUSIONS
  Jig selection and osteotomy type may lead to different post-correctional alignment results when performing distal femoral osteotomies. Whereas OWO allows accurate correction when used with either jig to address frontal plane deformities, the Deformity Reduction Device can be utilized with both CWO and OWO to correct torsion-angulation femoral deformities to optimize frontal plane alignment.
authors.affiliation: Matteo Olimpo, DVM, Struttura Didattica Speciale Veterinaria, University of Turin, Largo Paolo Braccini, 2-5, 10095 Grugliasco, Italy, Phone: +39 011 670 9061, Fax: +39 011 670 9165, E-mail: matteo.olimpo@gmail.com.
authors.forename: Matteo
authors.initials: M
authors.lastname: Olimpo
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Piras
authors.forename: Bruno
authors.initials: B
authors.lastname: Peirone
authors.forename: Derek B
authors.initials: DB
authors.lastname: Fox
mesh_terms: D000818:Animals; D004283:Dog Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D004285:Dogs / Q000601:surgery*; D005269:Femur / Q000000981:diagnostic imaging / Q000601:surgery*; D008953:Models, Anatomic; D010027:Osteotomy / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D031222:Patellar Dislocation / Q000000981:diagnostic imaging / Q000601:surgery / Q000662:veterinary*; D011859:Radiography
keywords: Patella luxation; alignment jig; corrective osteotomy; femoral deformities