Expression And Clinical Significance Of Calcitoningene Related Peptide In Pathological Tissue Of Congenital Pseudarthrosis Of Tibia

ObjectiveThe congenital pseudarthrosis of tibia(CPT) is a stubborn disease in pediatric orthopedics,its major clinical manifestation is non union.Many scholar had studied on the causes,pathobiology and treatments,but there is still no classical theory to interpret its origin and pathogenesy.And some scholars considered the contractible circinate coarctation of periosts was the cause of CPT,which hamper the normal growth of bone,and lead to non union finally.Whether there is originally anormal bone metabolism or not is still unknown.Recently peptidergic nerve has become the warm research spot all over the world,peptidergic nerve can take part in the bone metabolism by means of release neuropeptide,especially Calcitoningene related peptide (CGRP) has effects on the union of fracture.There is no research on the relationship between CPT and some neuropeptide.The objective of this study is to identify the expression of CGRP in the pathological tissue of CPT,in order to make a further research for the origin and pathogenesy of CPT.Method1.Specimen resource 1.1 Experiment group The specimen were the paraffin blocks of pathological periosteum and bone of pseudarthrosis of 10 CPT patients.The age of the patients were from 8 months to 5 years old,the average is 3.0years old.Among them,6 persons were male,and 4 persons were female.And 7 children's left tibias were invasive,and 3 children's right sides were invasive,there's no patient whose pseudarthrosis were detected in both tibias.1.2Control group Normal periosteum and bone were taken from CPT children whose fibula were normal and the children who were bow leg during operations,without pathological changes in tibia and fibula. The age range was from 2 to 8 years old,and the average age was 3years and 5months old.2.Paraffin section manufacture in routine method.3.HE stain to observe the pathological changes.4.Immunohistochemistry stain:The sections were processed immunohistochemically to detecte the expression of CGRP in experiment and control groups by means of the avidin-biotin-peroxidase complex (ABC) method.5.Data processingThe mean optical density(MOD) of CGRP was acquired by pathology doctors by Image Pro Plus 5.0.Statistical analysis of two group t-test was performed by software SPSS 10.0.Results1.HE stain observationIn the periosteum from CPT patients,the common structure was not observed,instead of a quantity of fibroblasts and disordered hyperplastic collagen fibrils;the number of vascellum was less than control group,with vessel wall thickening and narrow lumina.In bone tissue from CPT patients,there were chaostic bone trabeculas with osteoclasts and osteoblasts around them,fibrous connective tissue compacted in the bone tissue,and there was some cartilage and osteonecrosis.2.Immunohistochemistry stain observation CGRP positive substance was located at vessel wall in periosts and intracytoplasm of osteoclasts and osteoblasts in bones,and expressed less in all these region of experimental group than in control group.ConclusionThe expressions of CGRP in pathological periosts and bone of CPT were anormal,which decreased the blood flow of bone of pseudarthrosis and increased the resorption of bone,and these anormal changes lead to the nonunion,CGRP may be one of causes of CPT.The major pathological changes of CPT appearance not only in periosts but also in bone.