ABSTRACT
<p><b>OBJECTIVE</b>To examine the changes of osteocalcin and insulin-like growth factor I (IGF-I) during bone lengthening, and to clarify the mechanism of bone healing.</p><p><b>METHODS</b>Thirty-two shepherd dogs were divided into five groups randomly. Their tibiae were lengthened by Ilvzarov's external fixator at the rate of 1 mm/day. The lengthening area was the experimental side and the opposite side was the control. Samples were obtained on the 2nd, 4th, 6th, 8th, 12th weekend respectively. The samples were defatted, dried, powdered, centrifuged and measured by radioimmunoassay.</p><p><b>RESULTS</b>The osteocalcin concentration increased at the subsequent periods, but it was significantly lower in the experimental side than that of the control side, P<0.05 and the IGF-I concentration was not significantly lowered.</p><p><b>CONCLUSIONS</b>Different noncollagenous bone growth factors may be different at different stage.</p>
Subject(s)
Animals , Dogs , Female , Male , Analysis of Variance , Biomarkers , Bone Lengthening , Methods , Disease Models, Animal , Insulin-Like Growth Factor I , Metabolism , Osteocalcin , Metabolism , Probability , Radioimmunoassay , Random Allocation , Sensitivity and Specificity , Statistics, Nonparametric , Tibia , General SurgeryABSTRACT
<p><b>OBJECTIVE</b>To explore chemical component changes of dog bone at different lengthening time and in different bone regions of interest, and to evaluate the mineralization during Ilizarov lengthening process.</p><p><b>METHODS</b>The ash weight, the concentrations of calcium, phosphorus and the calcium/phosphorus ratio were measured at different intervals (2, 4, 6, 8, 12 weeks) since lengthening and the lengthened part was compared with a control area at each interval.</p><p><b>RESULTS</b>The ash weight, the concentrations of calcium and phosphorus in the lengthened area differed at all development time. The calcium/phosphorus (Ca/P) ratio in the lengthened region remained significantly lower than that in the control region up to 12 weeks after the lengthening.</p><p><b>CONCLUSIONS</b>These results suggest that also other inorganic ions play an important role in the mineralization process and that they become relatively more important since 8 weeks after the lengthening.</p>