title: A pilot study investigating the histology and growth factor content of human non-union tissue.
abstract: OBJECTIVE
  The reason for the formation of an atrophic non-union is not clear and an altered vascularization as well as a deregulation of endogenous growth factors is hypothesized. To obtain more information, we analysed human non-union tissue regarding the histology and quantity of several growth factors.
  
  
  METHODS
  Tissue from patients with an atrophic non-union (n = 44) or with a healed fracture (n = 13) was analysed. Using histological and immunohistochemical methods the tissue composition was investigated. On the protein level the amount of several growth factors important for bone healing was analysed.
  
  
  RESULTS
  The tissue composition was very inhomogeneous containing fibrous, cartilaginous and bony tissue. Vessels were present in all investigated samples without a difference between the tissue from non-union and control patients. The growth factor BMP-2 was below the detection limit in all samples, whereas IL-6 and IGF-I were measured only in a few samples of both groups. TGF-ß1, VEGF-A and BMP-4 were detectable in the majority of the samples of both groups with a high variability in the amount but no difference between the groups. The quantity of both growth factors, BMP-7 and PDGF-AB, was significantly lower in the non-union tissue compared to the healed controls.
  
  
  CONCLUSIONS
  The reduced quantity of BMP-7 and PDGF-AB might be responsible for the impaired healing. Further studies analysing material from more patients and investigating the early healing phases, however, are necessary to obtain further information and consequently improve healing strategies.
authors.affiliation: Julius Wolff Institute, Center for Musculoskeletal Surgery, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Schwabe
authors.forename: Paul
authors.initials: P
authors.lastname: Simon
authors.forename: Zienab
authors.initials: Z
authors.lastname: Kronbach
authors.forename: Gerhard
authors.initials: G
authors.lastname: Schmidmaier
authors.forename: Britt
authors.initials: B
authors.lastname: Wildemann
mesh_terms: D000328:Adult; D000368:Aged; D055396:Bone Morphogenetic Protein 2 / Q000378:metabolism; D055419:Bone Morphogenetic Protein 7 / Q000378:metabolism; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D001842:Bone and Bones; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D017102:Fracture Healing / Q000502:physiology*; D005599:Fractures, Ununited / Q000503:physiopathology*; D006801:Humans; D007150:Immunohistochemistry; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008875:Middle Aged; D010865:Pilot Projects; D010982:Platelet-Derived Growth Factor; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D055396:Bone Morphogenetic Protein 2; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; D016207:Cytokines; D015850:Interleukin-6; D010982:Platelet-Derived Growth Factor; D053773:Transforming Growth Factor beta1; D042461:Vascular Endothelial Growth Factor A; C095477:platelet-derived growth factor AB; D007334:Insulin-Like Growth Factor I