title: [Morphological observation on repairing articular cartilage defects with collagen complex gradient TCP].
abstract: OBJECTIVE
  To repair the defects in articular cartilage with collagen complex gradient TCP in vivo and to study the regenerated cartilage histomorphologically.
  
  
  METHODS
  The models of defects in articular cartilage were made artificially in both condylus lateralis femoris of mature rabbits, male or female, with the weight of 2.0-2.5 kg. The right defects were implanted with the material of Col/TCP as the experimental group and the left defects were untreated as the control group. The rabbits were killed at 4, 6, 8, 12 and 24 weeks after operation, respectively, with 6 ones at each time, and the macroscopic, histological, ultrastructural examinations and semi-quantity cartilage scoring employing Wakitanifa repaired cartilage value system were performed.
  
  
  RESULTS
  Four weeks after operation, the defects in the experimental group were partly filled with hyaline cartilage. Twelve weeks after operation, the defects in the experimental group were completely filled with mature hyaline cartilage. Twenty-four weeks after operation, regenerated cartilage had no cataplasia. However, fibrous tissues were seen in the control group all the time. At 4, 6, 8, 12 and 24 weeks postoperatively, the Wakitanifa cartilage scores were 7.60 +/- 0.98, 5.69 +/- 0.58, 4.46 +/- 0.85, 4.35 +/- 0.12 and 4.41 +/- 0.58, respectively, in the experimental group and 10.25 +/- 1.05, 9.04 +/- 0.96, 8.96 +/- 0.88, 8.88 +/- 0.68 and 8.66 +/- 0.54, respectively, in the control group. At 4, 6, 8, 12 and 24 weeks postoperatively, the collagen II contents were 0.28% +/- 0.01%, 0.59% +/- 0.03%, 0.68% +/- 0.02%, 0.89% +/- 0.02% and 0.90% +/- 0.01%, respectively, in the experimental group, while 0.08% +/- 0.02%, 0.09% +/- 0.04%, 0.11% +/- 0.03%, 0.25% +/- 0.03% and 0.29% +/- 0.01%, respectively, in the control group. Differences between the control group and the experimental group were significant (P < 0.05). By then, typical chondrocyte was observed by transmission electron microscope in the experimental group and much fiber with less fibrocyte was observed in the control group.
  
  
  CONCLUSIONS
  Three-dimensional scaffold collagen complex gradient TCP may induce cartilage regeneration to repair the defects of articular cartilage in vivo.
authors.affiliation: Department of Joint Surgery, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou Guangdong, PR China.
authors.forename: Guoqing
authors.initials: G
authors.lastname: Zha
authors.forename: Weiming
authors.initials: W
authors.lastname: Liao
authors.forename: Yingjun
authors.initials: Y
authors.lastname: Wang
authors.forename: Gang
authors.initials: G
authors.lastname: Wu
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D002357:Cartilage Diseases / Q000473:pathology / Q000601:surgery*; D002358:Cartilage, Articular / Q000473:pathology; D017690:Cell Transplantation; D003094:Collagen / Q000627:therapeutic use*; D011817:Rabbits; D023822:Tissue Engineering / Q000379:methods
chemical_list: D003094:Collagen