title: Heterologous mesenchymal stem cells successfully treat femoral pseudarthrosis in rats.
abstract: BACKGROUND
  This study evaluated the effectiveness of treating pseudarthrosis in rats by using bone marrow cell suspensions or cultures of bone marrow mesenchymal stromal cells
  
  
  METHODS
  Thirty-eight specific pathogen-free (SPF) animals were randomly assigned to four groups: Group 1, Control, without surgical intervention; Group 2 (Placebo), experimental model of femoral pseudarthrosis treated only with saline solution; Group 3, experimental model of femoral pseudarthrosis treated with heterologous bone marrow cells suspension; Group 4, experimental model of femoral pseudarthrosis treated with cultures of heterologous mesenchymal stromal cells from bone marrow. When pseudarthrosis was confirmed by simple radiological studies, digital radiography and histopathology after a 120-day postoperative period, Groups 2, 3 and 4 were treated as above. At 30, 60 and 90 days after the treatment, all animals were evaluated by simple radiological studies, and at the end of the experiment, the animals were assessed by computed axial tomography and anatomopathological and histomorphometric examinations.
  
  
  RESULTS
  Injected cells were detected in the areas affected by pseudarthrosis using scintigraphy within the first 24 hours after their administration. After 60 days, the animals of Group 3 showed callus formation while the animals of Group 4 presented periosteal reaction and had some consolidated areas. In contrast, Group 2 showed a predominance of fibro-osteoid tissue. After 90 days, bone consolidation and remodeling was observed in all animals from Group 3 whereas animals from Group 4 exhibited partial consolidation and those ones from Group 2 persisted with pseudarthrosis.
  
  
  CONCLUSIONS
  The treatment with heterologous bone marrow cells suspension proved to be effective in the treatment of pseudarthrosis whereas cultures of heterologous bone marrow mesenchymal stromal cells did not show the same potential to aid bone healing.
authors.affiliation: Post-graduate Program in Surgical Sciences, Department of Surgery, School of Medicine, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. louiz_25@yahoo.com.br
authors.forename: Manoel Luiz
authors.initials: ML
authors.lastname: Ferreira
authors.forename: Paulo Cesar
authors.initials: PC
authors.lastname: Silva
authors.forename: Lucas Henrique
authors.initials: LH
authors.lastname: Alvarez Silva
authors.forename: Danielle Cabral
authors.initials: DC
authors.lastname: Bonfim
authors.forename: Lucas Cristo
authors.initials: LC
authors.lastname: Conilho Macedo Müller
authors.forename: Christiano Costa
authors.initials: CC
authors.lastname: Espósito
authors.forename: Alberto
authors.initials: A
authors.lastname: Schanaider
mesh_terms: D000818:Animals; D005269:Femur / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D007267:Injections; D007383:Intermittent Claudication; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D010919:Placebos; D011542:Pseudarthrosis / Q000000981:diagnostic imaging / Q000601:surgery / Q000628:therapy*; D011859:Radiography; D011877:Radionuclide Imaging; D051381:Rats; D014054:Tomography
chemical_list: D010919:Placebos