title: A new method for meniscus repair using type I collagen scaffold and infrapatellar fat pad.
abstract: OBJECTIVE
  The aim of this study was to investigate a new method for meniscal repair by combinative transplantation with type I collagen scaffold and infrapatellar fat pad.
  
  
  METHODS
  Two-mm cylindrical defects at the anterior part of bilateral medial menisci were prepared in nine Japanese white rabbits. The 18 knees were equally divided into three groups: I, no treatment; II, collagen scaffold transplantation; and III, collagen scaffold and infrapatellar fat pad transplantation. Another three rabbits (six knees) underwent sham surgery and served as controls. Rabbits were sacrificed at eight weeks after transplantation. Surface area of the medial meniscus was evaluated using macrophotographs. Ishida score for meniscal regeneration was used for assessment. To evaluate the composition of regenerated tissue, immunohistochemistry was analyzed with anti-type I and anti-type II collagen antibodies, and anti-Ki67 antibody. To investigate the effects of collagen scaffold on human meniscus, cells were isolated from human meniscus and infrapatellar fat pad, and cultured with collagen scaffold for three weeks. After that, gene expression was evaluated by using quantitative real-time polymerase chain reaction.
  
  
  RESULTS
  In group I, the meniscus shrank anterior to posterior, and the surface area was significantly less than that of normal meniscus. However, the surface area was maintained in group III. Ishida score and Ki67-positive cell ratio in group III were significantly higher than that in any other group, and staining with type I and type II collagen was similar to that of the control. Expression of matrix metalloproteinase was significantly lower in cocultures of collagen scaffold, meniscus cell, and infrapatellar fat pad cell than in monocultured meniscus cell, and expression of interleukin-1β was not increased.
  
  
  CONCLUSIONS
  This new method for meniscal repair by combinative transplantation with type I collagen scaffold and infrapatellar fat pad showed meniscal regeneration and potential for suppressing inflammation.
authors: Department of Orthopedic Surgery, Osaka Medical College, Japan.
authors: Shuhei
authors: S
authors: Oda
authors: Department of Orthopedic Surgery, Osaka Medical College, Japan ort182@poh.osaka-med.ac.jp.
authors: Shuhei
authors: S
authors: Otsuki
authors: Department of Orthopedic Surgery, Osaka Medical College, Japan.
authors: Yoshitaka
authors: Y
authors: Kurokawa
authors: Department of Orthopedic Surgery, Osaka Medical College, Japan.
authors: Yoshiaki
authors: Y
authors: Hoshiyama
authors: Department of Orthopedic Surgery, Osaka Medical College, Japan.
authors: Mikio
authors: M
authors: Nakajima
authors: Department of Orthopedic Surgery, Osaka Medical College, Japan.
authors: Masashi
authors: M
authors: Neo
mesh_terms: D000273:Adipose Tissue / Q000637:transplantation*; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002478:Cells, Cultured; D024042:Collagen Type I / Q000737:chemistry*; D015870:Gene Expression; D006801:Humans; D008422:Materials Testing; D008592:Menisci, Tibial / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D010329:Patella / Q000601:surgery; D011817:Rabbits; D012038:Regeneration; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D024042:Collagen Type I
keywords: Meniscus; collagen scaffold; infrapatellar fat pad; meniscus repair; mesenchymal stem cell