title: Osteochondral autograft transplantation in the porcine knee.
abstract: BACKGROUND
  Knee articular cartilage defects are not an uncommon problem. Because articular cartilage is limited in its ability to heal, these defects are difficult to manage.
  
  
  OBJECTIVE
  Osteochondral autografts will provide less of a cavitary defect and more viable hyaline articular cartilage than will control knees.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Osteochondral autografts were grossly and microscopically evaluated in the porcine knee and compared with a control at 6 weeks, 3 months, and 6 months. In 18 porcine specimens, a 1-stage surgical procedure was performed to harvest an osteochondral graft from a nonweightbearing articular cartilage surface, and the graft was transplanted into a defect created in the weight-bearing region of the medial femoral condyle. In the opposite control knee, a similar defect was created in the medial femoral condyle; an osteochondral transplant was not performed. Six pigs each were sacrificed at 6 weeks, 3 months, and 6 months.
  
  
  RESULTS
  Gross inspection of the control knees showed a cavitary defect. The defect grossly decreased in size with fibrous ingrowth seen on microscopic analysis. An increasing amount of fibrous tissue and fibrocartilage was present at the 3 time periods. Gross inspection of the graft knee showed a healed osteochondral plug with no obvious displacement, cavitary defects, or surrounding necrotic tissue at each time interval. Microscopic analysis revealed the graft knee contained viable hyaline cartilage and healed viable subchondral bone. At all time intervals, 75% to 100% of the hyaline cartilage was viable in all specimens. In 6-month specimens, bridging cartilage at the autograft-host junction was incomplete in 50%, partial in 33%, and complete in 17%.
  
  
  CONCLUSIONS
  Osteochondral autografts in the porcine knee resulted in viable hyaline cartilage for up to 6 months; there was inconsistent bridging hyaline cartilage at the periphery. Grafts appeared to heal into existing subchondral bone without displacement or evidence of necrosis.
  
  
  CONCLUSIONS
  This type of osteochondral transplant can be used as a reliable reconstructive alternative for osteochondral defects.
authors.affiliation: Department of Orthopaedic Surgery and Rehabilitation, Texas Tech University Health Science Center, 3601 4th Street STOP 9436, Lubbock, Texas 79430, USA. bcole@ortho4.pro.rpslmc.edu
authors.forename: Bradley D
authors.initials: BD
authors.lastname: Harman
authors.forename: Steven H
authors.initials: SH
authors.lastname: Weeden
authors.forename: Derek K
authors.initials: DK
authors.lastname: Lichota
authors.forename: George W
authors.initials: GW
authors.lastname: Brindley
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000473:pathology / Q000637:transplantation*; D007719:Knee Joint / Q000473:pathology / Q000601:surgery*; D013552:Swine; D014182:Transplantation, Autologous / Q000473:pathology