Correlation of growth factor levels at the fusion site of diabetic patients undergoing hindfoot arthrodesis and clinical outcome

The effects of local insulin application to lumbar spinal fusions in a rat model

“…Multiple studies have explored the effects of local insulin application on bone formation [7][8][9][11][12][13][14][15][16][17]. Stuck [11] found more advanced healing microscopically in a rabbit fibula osteotomy model for animals injected with intravenous insulin.…”

“…The total amount of protein for each sample was measured by bicinchoninic acid analysis (Pierce, Rockford, IL, USA), followed by enzymelinked immunosorbent assay for individual growth factors. Previous studies from our laboratory demonstrated altered levels of PDGF-AB, VEGF, and insulinlike growth factor-I (IGF-I) in the fusion site of diabetic patients undergoing hindfoot fusions [8]. Therefore, these growth factors maybe altered in the process of spinal fusion when treated with local insulin.…”

“…Therefore, these growth factors maybe altered in the process of spinal fusion when treated with local insulin. The growth factor levels were normalized to total protein levels to eliminate variability within samples as described in previous studies [7,8]. …”

“…The fusion bed and transverse processes were harvested, immediately frozen in liquid nitrogen, and pulverized. Total protein was extracted from the pulverized bone using standard techniques described in previous studies [7,8]. After the extraction, the supernatant was isolated by centrifugation (12,000 rpm for 10 minutes) and stored at À80 C until tested.…”

“…The local microenvironment and growth factor levels are critical for any osseous fusion. Previous studies by Verma et al [8] analyzed the levels of growth factors in the fusion site of diabetics undergoing hindfoot fusion. Samples were taken at the time of fusion, and patients were followed clinically for signs of fusion.…”