title: Formation of cartilage repair tissue in articular cartilage defects pretreated with microfracture and covered with cell-free polymer-based implants.
abstract: The aim of our study was to evaluate the mid-term outcome of a cell-free polymer-based cartilage repair approach in a sheep cartilage defect model in comparison to microfracture treatment. Cell-free, freeze-dried implants (chondrotissue) made of a poly-glycolic acid (PGA) scaffold and hyaluronan were immersed in autologous serum and used for covering microfractured full-thickness articular cartilage defects of the sheep (n = 4). Defects treated with microfracture only served as controls (n = 4). Six months after implantation, cartilage implants and controls were analyzed by immunohistochemical staining of type II collagen, histological staining of proteoglycans, and histological scoring. Histological analysis showed the formation of a cartilaginous repair tissue rich in proteoglycans. Histological scoring documented significant improvement of repair tissue formation when the defects were covered with the cell-free implant, compared to controls treated with microfracture. Immunohistochemistry showed that the cell-free implant induced cartilaginous repair tissue and type II collagen. Controls treated with microfracture showed marginal formation of a mixed-type repair tissue consisting of cartilaginous tissue and fibro-cartilage. Covering of microfractured defects with the cell-free polymer-based cartilage implant is suggested to be a promising treatment option for cartilage defects and improves the regeneration of articular cartilage.
authors.affiliation: Department of Traumatology and Orthopaedic Surgery, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Erggelet
authors.forename: Michaela
authors.initials: M
authors.lastname: Endres
authors.forename: Katja
authors.initials: K
authors.lastname: Neumann
authors.forename: Lars
authors.initials: L
authors.lastname: Morawietz
authors.forename: Jochen
authors.initials: J
authors.lastname: Ringe
authors.forename: Kathrin
authors.initials: K
authors.lastname: Haberstroh
authors.forename: Michael
authors.initials: M
authors.lastname: Sittinger
authors.forename: Christian
authors.initials: C
authors.lastname: Kaps
mesh_terms: D000818:Animals; D054544:Arthroplasty, Subchondral; D002358:Cartilage, Articular / Q000378:metabolism / Q000473:pathology / Q000502:physiology*; D024043:Collagen Type II / Q000378:metabolism; D005260:Female; D006820:Hyaluronic Acid; D023421:Models, Animal; D011100:Polyglycolic Acid; D011108:Polymers; D019736:Prostheses and Implants; D012038:Regeneration / Q000502:physiology; D012756:Sheep; D054457:Tissue Scaffolds; D016896:Treatment Outcome
chemical_list: D024043:Collagen Type II; D011108:Polymers; D011100:Polyglycolic Acid; D006820:Hyaluronic Acid