title: Image-Guided Techniques Improve the Short-Term Outcome of Autologous Osteochondral Cartilage Repair Surgeries: An Animal Trial.
abstract: OBJECTIVE
  Autologous osteochondral cartilage repair is a valuable reconstruction option for cartilage defects, but the accuracy to harvest and deliver osteochondral grafts remains problematic. We investigated whether image-guided methods (optically guided and template guided) can improve the outcome of these procedures.
  
  
  METHODS
  Fifteen sheep were operated to create traumatic chondral injuries in each knee. After 4 months, the chondral defect in one knee was repaired using (a) conventional approach, (b) optically guided method, or (c) template-guided method. For both image-guided groups, harvest and delivery sites were preoperatively planned using custom-made software. During optically guided surgery, instrument position and orientation were tracked and superimposed onto the surgical plan. For the template-guided group, plastic templates were manufactured to allow an exact fit between template and the joint anatomy. Cylindrical holes within the template guided surgical tools according to the plan. Three months postsurgery, both knees were harvested and computed tomography scans were used to compare the reconstructed versus the native pre-injury joint surfaces. For each repaired defect, macroscopic (International Cartilage Repair Society [ICRS]) and histological repair (ICRS II) scores were assessed.
  
  
  RESULTS
  Three months after repair surgery, both image-guided surgical approaches resulted in significantly better histology scores compared with the conventional approach (improvement by 55%, P < 0.02). Interestingly, there were no significant differences found in cartilage surface reconstruction and macroscopic scores between the image-guided and the conventional surgeries.
authors.affiliation: School of Computing, Queen's University, Kingston, Ontario, Canada.
authors.forename: Manuela
authors.initials: M
authors.lastname: Kunz
authors.affiliation: Department of Mechanical and Materials Engineering, Queen's University, Kingston, Ontario, Canada.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Devlin
authors.affiliation: Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Mark B
authors.initials: MB
authors.lastname: Hurtig
authors.affiliation: Department of Mechanical and Materials Engineering, Queen's University, Kingston, Ontario, Canada ; Department of Chemical Engineering, Queen's University, Kingston, Ontario, Canada.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Waldman
authors.affiliation: Department of Surgery, Queen's University, Kingston, Ontario, Canada.
authors.forename: John F
authors.initials: JF
authors.lastname: Rudan
authors.affiliation: Department of Surgery, Queen's University, Kingston, Ontario, Canada.
authors.forename: Davide D
authors.initials: DD
authors.lastname: Bardana
authors.affiliation: School of Computing, Queen's University, Kingston, Ontario, Canada.
authors.forename: A James
authors.initials: AJ
authors.lastname: Stewart
keywords: animal study; autologous osteochondral cartilage repair; computer-assisted surgery; image-guided surgery