title: Heterotopic autologous chondrocyte transplantation--a realistic approach to support articular cartilage repair?
abstract: Injured articular cartilage is limited in its capacity to heal. Autologous chondrocyte transplantation (ACT) is a suitable technique for cartilage repair, but it requires articular cartilage biopsies for sufficient autologous chondrocyte expansion in vitro. Hence, ACT is restricted by donor-site morbidity and autologous articular chondrocytes availability. The use of nonarticular heterotopic chondrocytes such as auricular, nasoseptal, or costal chondrocytes for ACT might overcome these limitations: heterotopic sources show lesser donor-site morbidity and a comparable extracellular cartilage matrix synthesis profile to articular cartilage. However, heterotopic (h)ACT poses a challenge. Particular tissue characteristics of heterotopic cartilage, divergent culturing peculiarities of heterotopic chondrocytes, and the advantages and drawbacks related to these diverse cartilage sources were critically discussed. Finally, available in vitro and in vivo experimental (h)ACT approaches were summarized. The quality of the cartilage engineered using heterotopic chondrocytes remains partly controversy due to the divergent methodologies and culture conditions used. While some encouraging in vivo results using (h)ACT have been demonstrated, standardized culturing protocols are strongly required. However, whether heterotopic chondrocytes implanted into joint cartilage defects maintain their particular tissue properties or can be adapted via tissue engineering strategies to fulfill regular articular cartilage functions requires further studies.
authors.affiliation: Department of Trauma and Reconstructive Surgery, Charité-Universitätsmedizin, Berlin, Germany.
authors.forename: Karym
authors.initials: K
authors.lastname: El Sayed
authors.forename: Andreas
authors.initials: A
authors.lastname: Haisch
authors.forename: Thilo
authors.initials: T
authors.lastname: John
authors.forename: Ulrike
authors.initials: U
authors.lastname: Marzahn
authors.forename: Anke
authors.initials: A
authors.lastname: Lohan
authors.forename: Riccarda D
authors.initials: RD
authors.lastname: Müller
authors.forename: Benjamin
authors.initials: B
authors.lastname: Kohl
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Ertel
authors.forename: Katharina
authors.initials: K
authors.lastname: Stoelzel
authors.forename: Gundula
authors.initials: G
authors.lastname: Schulze-Tanzil
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000166:cytology* / Q000473:pathology*; D019902:Chondrocytes / Q000166:cytology / Q000637:transplantation*; D006801:Humans; D023822:Tissue Engineering; D014182:Transplantation, Autologous; D016042:Transplantation, Heterotopic; D014945:Wound Healing