title: Chondrocyte survival and material properties of hypothermically stored cartilage: an evaluation of tissue used for osteochondral allograft transplantation.
abstract: BACKGROUND
  There is little information available on the material properties of hypothermically stored allograft specimens used to repair osteochondral defects.
  
  
  OBJECTIVE
  To analyze the effect of hypothermic storage on the material properties of fresh knee specimens over a 60-day interval.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Twelve sheep knee condyles were isolated. The femoral and tibial condyles and the patella were stored in a nutritive medium containing Dulbecco's Modified Eagle's Medium for 1, 8, 15, 29, 45, or 60 days. Total chondrocyte density, chondrocyte viability, matrix proteoglycan content, matrix water content, and matrix dynamic modulus of elasticity were determined.
  
  
  RESULTS
  Mean chondrocyte viability decreased significantly over the storage interval: 100% (day 1), 98.2% (day 8), *80.2% (day 15), *80.6% (day 29), *64.6% (day 45), and *51.6% (day 60) (* P < 0.05). Qualitative analysis demonstrated a preponderance of nonviable chondrocytes in the superficial cartilage layer. Significant decreases in matrix proteoglycan were observed in day 15 through day 60 specimens (P < 0.05). The matrix dynamic modulus significantly decreased from day 1 through day 60 (P < 0.05).
  
  
  CONCLUSIONS
  The material properties of hypothermically stored knee condyles progressively decline over 60 days.
  
  
  CONCLUSIONS
  This observed decline may have significant ramifications on long-term graft survival following stored-allograft implantation.
authors.affiliation: Laboratory for Soft Tissue Research, Hospital for Special Surgery, New York, New York 10021, USA.
authors.forename: Riley J
authors.initials: RJ
authors.lastname: Williams
authors.forename: James C
authors.initials: JC
authors.lastname: Dreese
authors.forename: Chih-Tung
authors.initials: CT
authors.lastname: Chen
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001696:Biomechanical Phenomena; D002358:Cartilage, Articular / Q000502:physiology* / Q000637:transplantation; D002452:Cell Count; D002470:Cell Survival; D019902:Chondrocytes / Q000502:physiology* / Q000637:transplantation; D005109:Extracellular Matrix / Q000502:physiology* / Q000637:transplantation; D005434:Flow Cytometry; D016014:Linear Models; D012034:Refrigeration; D012756:Sheep; D013314:Stress, Mechanical; D014021:Tissue Preservation / Q000379:methods*; D014184:Transplantation, Homologous