Growth factor expression during the development of atrophic non-union.
The aim of the study was to determine, for the first time, the distribution of expression of several important growth factors during the development of atrophic non-unions using an animal model. The sites of expression of TGFbeta, PDGF, FGFb, and BMP 2/4 were determined at the osteotomy sites of both normally healing bones and within atrophic non-unions at 1 and 8 weeks after operation using immunolocalization techniques. At 1 week after operation, the osteotomy gaps of the control group contained fracture haematoma and surrounding granulation tissue, whereas the osteotomy gaps of the non-union group contained only haematoma. The tissues of both the non-union and control groups demonstrated the same presence and distribution of growth factors. By 8 weeks after the operation, the control group osteotomy gaps were filled with bone within which the active osteoblasts stained positively for each of the growth factors. At 8 weeks, the osteotomy gaps of the non-union group contained only fibrous tissue, which failed to stain positively for any of the factors. These findings suggest that the development of atrophic non-union is not directly due to a lack of these four growth factors.
Brownlow
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Nuffield Department of Orthopaedic Surgery, Nuffield Orthopaedic Centre, OX3 7LD, Oxford, UK.
Reed
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Simpson
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AH
D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000378:metabolism*; D019902:Chondrocytes / Q000378:metabolism; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism*; D017102:Fracture Healing / Q000502:physiology; D005599:Fractures, Ununited / Q000378:metabolism* / Q000503:physiopathology; D023421:Models, Animal; D010006:Osteoblasts / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000378:metabolism*; D011817:Rabbits; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D029961:Zebrafish Proteins
D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D010982:Platelet-Derived Growth Factor; D016212:Transforming Growth Factor beta; D029961:Zebrafish Proteins; C405936:bmp2b protein, zebrafish; D016222:Fibroblast Growth Factor 2