title: Cultured autologous bone marrow stem cells inhibit bony fusion in a rabbit model of posterolateral lumbar fusion with autologous bone graft.
abstract: Mesenchymal stem cells (MSCs) have been isolated from various tissues and expanded in culture. MSCs add osteogenic potential to ceramic scaffolds when used together. A spinal fusion rabbit model was used to evaluate whether a pellet of cultured, autologous bone marrow MSCs (BMSCs) with osteogenic differentiation could increase the fusion rate when co-grafted with an autologous bone graft compared to autograft alone. Thirty rabbits were randomly assigned to two groups. Group 1 received bone autograft alone and Group 2 received bone autograft plus a pellet of cultured and differentiated BMSCs. Group 2 rabbits had a bone marrow puncture, after which the BMSC were cultured and osteoblastic differentiation was induced. BMSC cultures were obtained from 12 of 15 rabbits. The 27 rabbits underwent a bilateral, L4-L5 intertransverse fusion with an autograft and in Group 2 rabbits a pellet of differentiated BMSCs was added to the autograft. In Group 1, the fusion rate was 53% (8 of 15 rabbits) and in Group 2 the fusion rate was 0% (p<0.05). Adding differentiated BMSCs in a pellet without a scaffold not only failed to increase fusion rate, but completely inhibited bony growth.
authors.affiliation: Department of Orthopaedic Surgery, Pontificia Universidad Catolica de Chile, Marcoleta 352, Santiago, Chile. jurrutia@med.puc.cl
authors.forename: Julio
authors.initials: J
authors.lastname: Urrutia
authors.forename: Pablo
authors.initials: P
authors.lastname: Mery
authors.forename: Rafael
authors.initials: R
authors.lastname: Martínez
authors.forename: Felipe
authors.initials: F
authors.lastname: Pizarro
authors.forename: Daniel
authors.initials: D
authors.lastname: Apablaza
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Mardones
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D016026:Bone Marrow Transplantation; D002454:Cell Differentiation; D002478:Cells, Cultured; D008159:Lumbar Vertebrae; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D059630:Mesenchymal Stem Cells / Q000166:cytology; D011817:Rabbits; D013123:Spinal Fusion / Q000379:methods*; D014182:Transplantation, Autologous