title: Mapping Chondrocyte Viability, Matrix Glycosaminoglycan, and Water Content on the Surface of a Bovine Metatarsophalangeal Joint.
abstract: OBJECTIVE
  The purpose of this study was to determine if there were variations in chondrocyte viability, matrix glycosaminoglycan (GAG), and water content between different areas of the articular surface of a bovine metatarsophalangeal joint, a common and reliable source of articular cartilage for experimental study, which may compromise the validity of using multiple samples from different sites within the joint.
  
  
  METHODS
  Nine fresh cadaveric bovine metatarsophalangeal joints were obtained. From each joint, 16 osteochondral explants were taken from 4 facets, yielding a total of 144 cartilage specimens for evaluation of chondrocyte viability, matrix GAG, and water content. A less invasive method for harvesting osteochondral explants and for processing the biopsy for the assessment of chondrocyte viability was developed, which maintained maximal viability within each cartilage explant.
  
  
  RESULTS
  There was no significant difference between the 16 biopsy sites from the different areas of the joint surface with respect to chondrocyte viability, matrix GAG and water content. Pooled data of all samples from each joint established the baseline values of chondrocyte viability to be 89.4% ± 3.8%, 94.4% ± 2.2%, and 77.9% ± 7.8%, in the superficial quarter, central half, and deep quarter (with regard to depth from the articular surface), respectively. The matrix GAG content of bovine articular cartilage was 6.06 ± 0.41 μg/mg cartilage, and the cartilage water content was 72.4% ± 1.5%. There were also no significant differences of these 3 variables between the different joints.
  
  
  CONCLUSIONS
  It is thus reasonable to compare biopsies obtained from different sites, as a biopsy from one site would be considered representative of the whole joint.
authors.affiliation: Department of Orthopaedic and Trauma Surgery, The University of Edinburgh, Edinburgh, UK; Department of Orthopedic Surgery, Taipei Medical University - Shuang Ho Hospital, New Taipei City, Taiwan.
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Lin
authors.affiliation: Centre for Integrative Physiology, The University of Edinburgh, Edinburgh, UK.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Hall
authors.affiliation: Centre for Integrative Physiology, The University of Edinburgh, Edinburgh, UK.
authors.forename: Innes D M
authors.initials: ID
authors.lastname: Smith
authors.affiliation: Department of Pathology, The University of Edinburgh, Edinburgh, UK.
authors.forename: Donald M
authors.initials: DM
authors.lastname: Salter
authors.affiliation: Department of Orthopaedic and Trauma Surgery, The University of Edinburgh, Edinburgh, UK.
authors.forename: A Hamish R W
authors.initials: AH
authors.lastname: Simpson
keywords: chondrocyte viability; confocal microscopy; glycosaminoglycan content; joint mapping