title: Assessment of epiphyseal plate allograft viability and function after ex vivo storage in University of Wisconsin Solution.
abstract: BACKGROUND
  Compromised epiphyseal plate function can result in limb deformities. Microvascular transplantation of an epiphyseal plate allograft is a potentially effective approach to reestablish longitudinal limb growth. For this procedure to become clinically useful, the technique for temporary ex vivo storage of allografts must be reliable. The goal of this study was to determine a time frame for which proximal tibial epiphyseal plate allografts could be stored in University of Wisconsin Preservation Solution (UWPS) and remain functional in vivo after microvascular transplantation.
  
  
  METHODS
  Proximal tibial epiphyseal plate allografts from skeletally immature female New Zealand White rabbits (10 to 12 wk of age) were used. Allografts (isolated on the popliteal arteriovenous pedicle) were stored ex vivo in cold UWPS for periods of up to 21 days. Chondrocyte viability, phenotype, and extracellular matrix composition of growth plate cartilage was assessed. Microvascular transplantations of nonstored or prestored (3 d) allografts were performed and analysis of bromodeoxyuridine and calcein incorporation was done to determine chondrocyte proliferation and new bone growth, respectively.
  
  
  RESULTS
  In vitro analysis showed that, compared with control tissue, epiphyseal plate chondrocyte viability (P>0.05), organization, and collagen extracellular matrix was preserved up to 4 days in cold UWPS. Microvascular transplantation of nonstored epiphyseal plate allografts was successful. Despite care being taken to ensure vascular patency during the microvascular procedure, transplantation of prestored allografts failed due to absent flow in the larger vessels and in the allograft based upon the visualization of organized thrombus within the vascular pedicle, and absent flow within the composite graft itself. However, growth plate viability and function was detected in a peripheral region of a single allograft where partial blood flow had been maintained during the transplantation period.
  
  
  CONCLUSIONS
  Ex vivo storage in cold UWPS for 3 days maintains growth plate chondrocyte viability and function in vivo. However, future studies must be directed toward investigating the direct effect of ex vivo storage on the integrity and function of the vascular pedicles.
authors.affiliation: Department of Orthopaedic Surgery, Washington University School of Medicine, St Louis, MO 63110, USA.
authors.forename: Soumya
authors.initials: S
authors.lastname: Ravindran
authors.forename: Martin I
authors.initials: MI
authors.lastname: Boyer
authors.forename: Erin
authors.initials: E
authors.lastname: Martens
authors.forename: Helena
authors.initials: H
authors.lastname: Ntouvali
authors.forename: Audrey
authors.initials: A
authors.lastname: McAlinden
mesh_terms: D000818:Animals; D016025:Bone Transplantation / Q000379:methods*; D005260:Female; D006132:Growth Plate / Q000637:transplantation*; D008866:Microsurgery / Q000379:methods*; D019188:Organ Preservation Solutions; D011817:Rabbits; D015203:Reproducibility of Results; D013977:Tibia / Q000098:blood supply / Q000473:pathology / Q000637:transplantation; D013997:Time Factors; D014184:Transplantation, Homologous
chemical_list: D019188:Organ Preservation Solutions