title: Bone Mesenchymal Stem Cells with Growth Factors Successfully Treat Nonunions and Delayed Unions.
abstract: BACKGROUND
  While the gold standard of treatment of nonunion is open autologous bone grafting, studies have shown that injecting bone marrow aspirate concentrates (BMAC) is effective in treating tibial nonunions with fracture gaps less than 5 mm.
  
  
  OBJECTIVE
  We aim to demonstrate that combining BMAC with osteoinductive agents can effectively treat delayed or nonunion regardless of fracture gap size, nonunion site, or osteoinductive agent used.
  
  
  METHODS
  In this non-randomized retrospective-prospective cohort study, 49 patients with tibial nonunion met the inclusion criteria and underwent BMAC injection with demineralized bone matrix (DBM) and/or recombinant human bone morphogenic protein-2 (rhBMP-2). Radiologic healing of the fracture was the primary outcome. Patients were followed until radiographic union was achieved or another procedure was performed. Radiographic healing was defined as bridging of three out of four cortices on anteroposterior and lateral films.
  
  
  RESULTS
  There was no difference in the healing rate (p = 0.81) between patients with fracture gaps less than and greater than 5 mm. On multivariate analysis, the use of rhBMP-2 was associated with a lower healing rate compared to DBM (p = 0.036). Patients who underwent early intervention (within 6 months of fixation) had higher union rates (p = 0.04).
  
  
  CONCLUSIONS
  This study shows that percutaneous BMAC injection combined with either DBM and/or rhBMP-2 is a safe and effective treatment for delayed or nonunion regardless of the fracture gap size or fracture site. DBM may be superior to rhBMP-2 in this procedure.
authors.affiliation: Weill Cornell Medical College, 1300 York Ave, New York, NY 10065 USA ; Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021 USA.
authors.forename: Pingal
authors.initials: P
authors.lastname: Desai
authors.affiliation: Weill Cornell Medical College, 1300 York Ave, New York, NY 10065 USA.
authors.forename: Saad Mumtaz
authors.initials: SM
authors.lastname: Hasan
authors.affiliation: Weill Cornell Medical College, 1300 York Ave, New York, NY 10065 USA.
authors.forename: Lester
authors.initials: L
authors.lastname: Zambrana
authors.affiliation: Weill Cornell Medical College, 1300 York Ave, New York, NY 10065 USA.
authors.forename: Vishal
authors.initials: V
authors.lastname: Hegde
authors.affiliation: Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021 USA.
authors.forename: Anas
authors.initials: A
authors.lastname: Saleh
authors.affiliation: Weill Cornell Medical College, 1300 York Ave, New York, NY 10065 USA.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Cohn
authors.affiliation: Weill Cornell Medical College, 1300 York Ave, New York, NY 10065 USA ; Hospital for Special Surgery, 535 East 70th Street, New York, NY 10021 USA.
authors.forename: Joseph M
authors.initials: JM
authors.lastname: Lane
keywords: BMAC (concentrated autogenous iliac crest bone marrow aspirate); bone morphogenic protein; delayed union; demineralized bone matrix; modified Hernigou technique; nonunion