title: The Degree of Chondral Fragmentation Affects Extracellular Matrix Production in Cartilage Autograft Implantation: An In Vitro Study.
abstract: OBJECTIVE
  To evaluate if the degree of chondral fragmentation affected extracellular matrix (ECM) production in cartilage fragment autograft implantation in vitro.
  
  
  METHODS
  Cartilage was taken from 5 donors undergoing total hip replacement (mean age, 65.6 years; standard deviation [SD], 3). The cartilage was minced to obtain 4 groups with different fragment sizes: (1) "fish scale" (diameter, 8 mm; thickness, 0.3 mm), (2) cubes with 2-mm sides, (3) cubes with 1-mm sides, and (4) cartilage paste (< 0.3 mm). The cultures were maintained in chondrogenic medium for 6 weeks. Biochemically, a proteoglycan (PG):DNA ratio was calculated as the best approximation of ECM production per cell. The ratio between PG released in the culture medium and the PG in the neocartilage (PGrel:PG) was used as a matrix stability index. Histologically, the slides were stained with safranin O fast green and collagen type II immunostaining. The titration of safranin O-positive cells and the Bern score were calculated.
  
  
  RESULTS
  Regarding the PG:DNA ratio, group 4 performed significantly better than groups 1 (P = .001) and 3 (P = .02), whereas group 2 performed better than group 1 (P = .03). No significant difference was found regarding the PGrel:PG ratio and safranin O-positive cells. Regarding the Bern score, group 4 performed significantly better than groups 1 (P = .02), 2 (P = .04), and 3 (P = .03).
  
  
  CONCLUSIONS
  We conclude that human cartilage fragmentation significantly affects ECM production in vitro. Increased fragmentation enhances ECM production.
  
  
  CONCLUSIONS
  Assuming a similar behavior in vivo, we recommend mincing the cartilage into small pieces when performing the cartilage fragment autograft implantation technique in order to increase ECM production. Further in vitro studies investigating cartilage of younger nonarthritic donors, as well as in vivo studies, are needed.
authors: Department of Orthopaedics and Traumatology, University of Torino, CTO Hospital, Torino, Italy. Electronic address: davidebonasia@virgilio.it.
authors: Davide Edoardo
authors: DE
authors: Bonasia
authors: Department of Orthopaedics and Traumatology, University of Torino, Mauriziano "Umberto I" Hospital, Torino, Italy.
authors: Antongiulio
authors: A
authors: Marmotti
authors: Molecular Biology Center, University of Torino, Torino, Italy.
authors: Silvia
authors: S
authors: Mattia
authors: Department of Orthopaedics and Traumatology, University of Torino, CTO Hospital, Torino, Italy.
authors: Aurelio
authors: A
authors: Cosentino
authors: Department of Orthopaedics and Traumatology, University of Torino, CTO Hospital, Torino, Italy.
authors: Simone
authors: S
authors: Spolaore
authors: Department of Orthopaedics and Traumatology, University of Torino, CTO Hospital, Torino, Italy.
authors: Giorgio
authors: G
authors: Governale
authors: Department of Orthopaedics and Traumatology, University of Torino, CTO Hospital, Torino, Italy.
authors: Filippo
authors: F
authors: Castoldi
authors: Department of Orthopaedics and Traumatology, University of Torino, Mauriziano "Umberto I" Hospital, Torino, Italy.
authors: Roberto
authors: R
authors: Rossi
mesh_terms: D000368:Aged; D000818:Animals; D019644:Arthroplasty, Replacement, Hip; D064592:Autografts; D002356:Cartilage / Q000293:injuries* / Q000637:transplantation*; D004247:DNA / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D006801:Humans; D011509:Proteoglycans / Q000378:metabolism
chemical_list: D011509:Proteoglycans; D004247:DNA