title: The use of a single osteochondral autograft plug in the treatment of a large osteochondral lesion in the femoral condyle: an experimental study in sheep.
abstract: BACKGROUND
  The use of osteochondral autograft plugs can be restricted because of limited amount of donor material.
  
  
  OBJECTIVE
  A small osteochondral autograft plug placed in the center of a large defect in a sheep femoral condyle will yield results superior to either an untreated or a bone-grafted defect.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Twelve adult sheep underwent bilateral hindlimb surgery. On 1 limb, a 6-mm circular osteochondral autograft plug was placed in the center of a 10-mm circular defect in the medial femoral condyle. The gap between the plug and the condyle was filled with bone graft. On the contralateral side, the defect was either left untreated or filled with bone graft (control specimens). Animals were studied at 6 and 12 months under gross examination, high-resolution radiography, and histologic evaluation.
  
  
  RESULTS
  At 6 months, 4 of 6 plugs healed and showed good maintenance of the joint surface and cartilage viability in the plugs. One plug fractured and resorbed, and 1 plug settled but healed. At 1 year, all 5 plugs healed, 1 having settled slightly (1 animal died earlier). The plug specimens showed better maintenance of the condyle contour at both times, and the central plug had hyaline-appearing cartilage. The control specimens were more irregular, had a fibrocartilage fill, and appeared flatter, although no gross cavitation or collapse was indicated. Composite cartilage scores on histologic evaluation were significantly higher for the plug specimens after 6 months (P = .02) and 1 year (P = .036) compared with controls.
  
  
  CONCLUSIONS
  At 6 months and 1 year, a 6-mm osteochondral plug placed in a 10-mm defect better preserved the articular surface and contour of the condyle compared to untreated or bone-grafted defects.
  
  
  CONCLUSIONS
  Osteochondral autograft plugs may be able to treat larger articular lesions without complete fill of the defect.
authors.affiliation: Department of Orthopedics, University of Utah, Salt Lake City, 84132, USA. robert.burks@hsc.utah.edu
authors.forename: Robert T
authors.initials: RT
authors.lastname: Burks
authors.forename: Patrick E
authors.initials: PE
authors.lastname: Greis
authors.forename: Steven Paul
authors.initials: SP
authors.lastname: Arnoczky
authors.forename: Courtney
authors.initials: C
authors.lastname: Scher
mesh_terms: D000818:Animals; D016025:Bone Transplantation / Q000379:methods*; D002358:Cartilage, Articular / Q000033:anatomy & histology / Q000637:transplantation*; D019902:Chondrocytes / Q000502:physiology / Q000637:transplantation*; D005269:Femur / Q000033:anatomy & histology / Q000473:pathology / Q000601:surgery*; D005500:Follow-Up Studies; D006085:Graft Survival; D007719:Knee Joint / Q000033:anatomy & histology / Q000601:surgery*; D010027:Osteotomy; D012756:Sheep; D014182:Transplantation, Autologous