title: Acetabular Labral Reconstruction With Autologous Tendon Tissue in a Porcine Model: In Vivo Histological Assessment and Gene Expression Analysis of the Healing Tissue.
abstract: BACKGROUND
  Acetabular labral reconstruction with autologous tendons is the preferred method for treating a severely damaged labrum. However, the healing process of implants remains unknown. Similar to the human acetabular labrum, the porcine acetabular labrum is a fibrocartilage-like tissue.
  
  
  OBJECTIVE
  This study aimed to characterize the histological healing process and gene expression profile of implants in a porcine model of acetabular labral reconstruction.
  
  
  METHODS
  Descriptive laboratory study.
  
  
  METHODS
  Eighteen pigs were included in this study. The pigs underwent unilateral acetabular labral reconstruction. A 1.0 cm-long defect was made at the site of the anterior (cranial) dorsal labrum, which was repaired using an autologous mesogluteus tendon. The pigs were sacrificed at 12 and 24 weeks postoperatively. The implants were subjected to histological assessment and gene expression analysis. The cell phenotype of the implants was visualized using paraffin-embedded sections.
  
  
  RESULTS
  Macroscopic observations revealed that at 12 weeks, 8 of 9 implants partially filled the labral defect; by contrast, at 24 weeks, 6 of 9 implants fully filled and 3 implants partially filled the labral defects. Oval- or round-shaped fibrochondrocytes were found in the implants at 12 and 24 weeks. The matrix staining results showed that proteoglycan and collagen types 1 and 2 were more evident in the implants at 24 weeks than at 12 weeks. Gene expression analysis results revealed that COL2A1 and COL3A1 were expressed by the implants to a higher extent at 24 weeks than at 12 weeks; COL2A1 and COL3A1 were also expressed to a higher extent in the implants than in the native tendon.
  
  
  CONCLUSIONS
  On the basis of the results of histological assessment and gene expression analysis, autologous tendon tissue for acetabular labral reconstruction can fully or partially fill labral defects and converts to fibrocartilage, which is rich in proteoglycan and collagen types 1 and 2, at 24 weeks in a porcine model.
  
  
  CONCLUSIONS
  Autologous tendon tissue can be considered as a viable option for acetabular labral reconstruction.
authors.affiliation: Institute of Sports Medicine, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing, China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Shi
authors.affiliation: Institute of Sports Medicine, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing, China.
authors.forename: Lin-Xin
authors.initials: LX
authors.lastname: Chen
authors.affiliation: Institute of Sports Medicine, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Institute of Sports Medicine, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing, China.
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: Hu
authors.affiliation: Institute of Sports Medicine, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing, China aoyingfang@163.com wjqsportsmed@163.com.
authors.forename: Ying-Fang
authors.initials: YF
authors.lastname: Ao
authors.affiliation: Institute of Sports Medicine, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing, China aoyingfang@163.com wjqsportsmed@163.com.
authors.forename: Jian-Quan
authors.initials: JQ
authors.lastname: Wang
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D000818:Animals; D002358:Cartilage, Articular / Q000601:surgery*; D019902:Chondrocytes / Q000378:metabolism; D024043:Collagen Type II / Q000235:genetics / Q000378:metabolism; D024061:Collagen Type III / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006621:Hip Joint / Q000601:surgery; D023421:Models, Animal; D013552:Swine; D013710:Tendons / Q000378:metabolism / Q000637:transplantation*; D014182:Transplantation, Autologous; D014945:Wound Healing
chemical_list: C499177:COL2A1 protein, human; C439971:COL3A1 protein, human; D024043:Collagen Type II; D024061:Collagen Type III
keywords: acetabular labral reconstruction; autologous tendon tissue; gene expression analysis; histological analysis