title: Histologic changes in articular cartilage after medial meniscus replacement in rabbits.
abstract: OBJECTIVE
  Meniscal allografts show capsular ingrowth, but it remains to be established whether meniscal transplantation can prevent long-term degeneration of articular cartilage. This study examined whether immediate or delayed transplantation of the medial meniscus can protect the knee from degenerative changes.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Thirty-five rabbits were divided into 5 groups. Three rabbits developed infective arthritis and were excluded from the study. Group A (6 animals) and group C (6 animals) had meniscectomy only; group B (7 animals) and group D (6 animals) underwent meniscal transplantation immediately after meniscectomy; group E (7 animals) had delayed transplantation 6 weeks after meniscectomy. Six nonoperated knees served as controls. Histologic changes of the articular cartilage were examined 6 weeks (groups A, B) and 1 year (groups C, D, E, controls) after surgery.
  
  
  RESULTS
  All operated groups showed more histologic changes than the control group (P < .00001 for both the medial tibial plateau and medial femoral condyle in all groups). At 6 weeks follow-up, no differences were found between the postmeniscectomy group and the transplanted group. At 1 year, immediately transplanted knees showed less degenerative changes than meniscectomized knees (P < .0001 for medial tibial plateau and P < .005 for medial femoral condyle). Delayed transplantation resulted in more degenerative changes than both meniscectomy only and immediate transplantation (for both comparisons, P < .00001 for both medial tibial plateau and medial femoral condyle).
  
  
  CONCLUSIONS
  Immediate meniscal transplantation in rabbits has a protecting effect on articular cartilage for the long-term whereas delayed transplantation leads to even more degenerative changes than meniscectomy only.
  
  
  CONCLUSIONS
  If these results are applicable to humans, they would support immediate, not delayed, transplantation after removal of a meniscus.
authors.affiliation: Department of Orthopaedic Surgery, Medical Centre Leeuwarden, Leeuwarden, The Netherlands. pcrijk@planet.nl
authors.forename: Paul C
authors.initials: PC
authors.lastname: Rijk
authors.forename: Wikky
authors.initials: W
authors.lastname: Tigchelaar-Gutter
authors.forename: Franz-Peter
authors.initials: FP
authors.lastname: Bernoski
authors.forename: Cornelis J F
authors.initials: CJ
authors.lastname: Van Noorden
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000473:pathology*; D005260:Female; D008592:Menisci, Tibial / Q000601:surgery*; D011817:Rabbits