title: Meniscus transplantation using treated xenogeneic meniscal tissue: viability and chondroprotection study in rabbits.
abstract: OBJECTIVE
  This was a preliminary study performed in vivo to evaluate the viability and the chondroprotective effects of irradiated deep-frozen xenogeneic meniscal tissue as a novel substitute for meniscus transplantation.
  
  
  METHODS
  Medial meniscectomies were performed on the right knees of 48 New Zealand white rabbits. The inner one-third of pig meniscus was harvested and then irradiated and deeply frozen. The treated xenogeneic meniscal tissues were then transplanted to 24 right knees (Xeno group), whereas 24 other knees received meniscus allograft transplantations (Allo group). The left knees of the Xeno group and Allo group received meniscectomies (Meni group) and sham operations (Sham group), respectively. The rabbits were killed at weeks 6, 12, and 24 postoperatively. The newly formed structure of the implanted tissue and cartilage of the medial compartment of each group was assessed by gross and semiquantitative histologic analysis.
  
  
  RESULTS
  After 24 weeks, the implanted xenogeneic meniscal tissue completely healed to the synovium and formed meniscus-like tissue. The chondrocyte-like cell infiltrated into the tissue with extracellular matrix including type II collagen and proteoglycans. The Xeno group showed significantly less cartilage degeneration than that of the Meni group in the medial tibial plateau at week 24 (P < .05). No significant difference was found between the Xeno group and the Allo group except for the meniscus-covered regions at week 24. From week 12 to week 24, almost no advanced cartilage degeneration was found in weight-bearing regions of the medial tibial plateau of the Xeno group.
  
  
  CONCLUSIONS
  The treated xenogeneic meniscal tissue healed to the synovium with tissue regeneration and slowed down articular cartilage degeneration in the short-term. The chondroprotection of xenograft transplantation was similar to that of allograft transplantation.
  
  
  CONCLUSIONS
  The treated xenogeneic meniscal tissue showed the potential for viability and slowed cartilage degeneration, but more studies are required for application in humans in the future.
authors.affiliation: Institute of Sports Medicine, Peking University Third Hospital, No. 49 North Garden Road, Haidian District, Beijing, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Jiang
authors.forename: Li-Heng
authors.initials: LH
authors.lastname: Zhao
authors.forename: Ming
authors.initials: M
authors.lastname: Tian
authors.forename: Ji-Ying
authors.initials: JY
authors.lastname: Zhang
authors.forename: Jia-Kuo
authors.initials: JK
authors.lastname: Yu
mesh_terms: D000818:Animals; D002357:Cartilage Diseases / Q000517:prevention & control; D002358:Cartilage, Articular / Q000033:anatomy & histology; D008297:Male; D008592:Menisci, Tibial / Q000637:transplantation*; D011183:Postoperative Complications / Q000517:prevention & control; D011817:Rabbits; D013552:Swine; D014183:Transplantation, Heterologous / Q000379:methods*