title: Evaluation of Spinal Fusion Using Bone Marrow Derived Mesenchymal Stem Cells with or without Fibroblast Growth Factor-4.
abstract: OBJECTIVE
  In this study, the authors assessed the ability of rat bone marrow derived mesenchymal stem cells (BMDMSCs), in the presence of a growth factor, fibroblast growth factor-4 (FGF-4) and hydroxyapatite, to act as a scaffold for posterolateral spinal fusion in a rat model.
  
  
  METHODS
  Using a rat posterolateral spine fusion model, the experimental study comprised 3 groups. Group 1 was composed of 6 animals that were implanted with 0.08 gram hydroxyapatite only. Group 2 was composed of 6 animals that were implanted with 0.08 gram hydroxyapatite containing 1 x 10(6)/ 60 microL rat of BMDMSCs. Group 3 was composed of 6 animals that were implanted with 0.08 gram hydroxyapatite containing 1 x 10(6)/ 60 microL of rat BMDMSCs and FGF-4 1 microG to induce the bony differentiation of the BMDMSCs. Rats were assessed using radiographs obtained at 4, 6, and 8 weeks postoperatively. After sacrifice, spines were explanted and assessed by manual palpation, high-resolution microcomputerized tomography, and histological analysis.
  
  
  RESULTS
  Radiographic, high-resolution microcomputerized tomographic, and manual palpation revealed spinal fusion in five rats (83%) in Group 2 at 8 weeks. However, in Group 1, three (60%) rats developed fusion at L4-L5 by radiography and two (40%) by manual palpation in radiographic examination. In addition, in Group 3, bone fusion was observed in only 50% of rats by manual palpation and radiographic examination at this time.
  
  
  CONCLUSIONS
  The present study demonstrates that 0.08 gram of hydroxyapatite with 1 x 10(6)/ 60 microL rat of BMDMSCs induced bone fusion. FGF-4, added to differentiate primitive 1 x 10(6)/ 60 microL rat of BMDMSCs did not induce fusion. Based on histologic data, FGF-4 appears to induce fibrotic change rather than differentiation to bone by 1 x 10(6)/ 60 microL rat of BMDMSCs.
authors.affiliation: Department of Neurosurgery, School of Medicine, Inha University, Incheon, Korea.
authors.forename: Hyun Sung
authors.initials: HS
authors.lastname: Seo
authors.forename: Jong Kwon
authors.initials: JK
authors.lastname: Jung
authors.forename: Mi-Hyun
authors.initials: MH
authors.lastname: Lim
authors.forename: Dong Keun
authors.initials: DK
authors.lastname: Hyun
authors.forename: Nam-Sik
authors.initials: NS
authors.lastname: Oh
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Yoon