Study On Sclerosis Rim Of Osteonecrosis Of The Femoral Head

Study on sclerosis rim of osteonecrosis of the femoral headObjective:To collect femoral heads from Osteonecrosis of the femoral head (ONFH)patients,analyze the morphological changes of sclerosis rim by histology,electron microscopy and immunohistochemistry methods.Study the relationship between the expression of BMP and VEGF and the formation of sclerosis rim,so as to acquire experimental and theoretical basis on personalized treatment for ONFH patients.Methods:Part 1,analysis of histological structure ofsclerosis rim of ONFH patients.143 cases of non-traumatic ONFH inpatients with 184 hips were collected from China-Japan Friendship Hospital during the time between 2005 to 2007,with average age of 47±7 years old.Their clinical data were retrospectively analyzed.Sclerosis rim was divided into 0,1 and 2 grades according to preoperative X-ray.Experimental hips were divided into four groups:alcohol osteonecrosis,steroid-induced osteonecrosis,osteoarthritis and fracture group,each group included 8 femoral heads.The femoral head of osteonecrosis groups were picked out from patients with obvious sclerosis rim. The femoral heads were cut along middle coronal plane,their weight-bearing and non-weight-bearing areas were used for the study.The specimens were processed by Routine HE staining and picric acid Sirius red staining and electron microscopy preparation.Histomorphometry,electron microscopy and histochemicl staining were applied to observe the histological changes of sclerosis rim of osteonecrosis of the femoral head. Part 2,Expression of VEGF and BMP in osteonecrosis of the femoral head and their correlationship with sclerosis rim.The clinical data of the patients was the same with part 1.the specimens of the femoral head were divided as following:11 hips from ONFH patients with age less than 40 year-old.60 hips with age between 40 to 54 year-old,including 30 hips from alcoholic patients and 30 hips from steroid-induced patients,according to the grades of sclerosis rim,they were divided into 3 groups with each 10 hips.18 hip with age more than 54-year-old.12 hips from patients with traumatic femoral neck fracture. VEGF and BMP immunohistochemistry stain was used SABC method.The quantitative optical density of BMP stain was analyzed by Image-Pro Plus 6.0 software,and VEGF staining by semi-quantitative method.Results:there wasnt gender difference in formation of sclerosis rim.The ratio of formation of sclerosis rim was 71.43%for patients between 40 to 54 years olds,45.45%for patients less than 40-year olds,38.46%for patients more than 54-year-old,and there was significant difference among 3 groups(P＜0.05); The ratio of formation of sclerosis rim in alcohol osteonecrosis group was significantly higher than steroid-induced and idiopathic patients(X~2=12.17.P＜0.01;X~2=8.549,P＜0.01);the longer the time from hip pain to joint replacement,the more grading of sclerosis rim.The trabecular of sclerosis rim was thickening.it's extracellular matrix was typeⅠandⅢcollagen,and it's trabecular bone cells was same with normal cells through analysis of electron microscopy,but it's structural was disorder.The bone formation and absorption index in sclerosis rim were greater than weight and non-weight-bearing areas for alcohol and steroid-induced ONFH patients.The surface of osteoblasts in weighs and non-weight-bearing area for alcoholic patients were respectively greater than steroid-induced patients (t=4.195,P＜0.01;t=5.324,P＜0.01). According to grading of sclerosis belt,namely 0,1and2-class,both alcoholic and steroid-induced femoral head were divided into three groups.The optical density in alcoholic and steroid-induced femoral head with BMP were respectively 0.206,0.219 and 0.263,the difference between the three groups were statistically(P＜0.05).Steroid-induced groups were respectively 0.195, 0.209 and 0.246,there was insignificant between the first two groups(P＞0.05), but the difference between the first two and the latter groups was statistically (t=3.018,P＜0.01;t=2.704,P＜0.05).The expression of BMP protein in femoral head from 40 to 54 years old patients was stronger than the other two groups. The expression of Smad4 protein in femoral head from Less than 54-year-old patients was stronger than greater than 54-year-old patients.The average optical density in femoral head of ONFH patients with age greater than 54-year-old was 0.193,wich was significantly less than the fracture group, namely 0.205(t=2.347,P＜0.05).The expression of VEGF in different areas of the femoral head from alcohol ONFH patients was similar to steroid-induced ONFH patients,which was strong on the sclerosis rim edge,but weak in sclerosis rim.Conclusion:Sclerosis rim responded to osteonecrosis of the femoral head was an protective factors from its collapse.The formation of sclerosis belt had nothing to do with gender,but with age and etiology.The higher expression of BMP and VEGF protein in femoral head from ONFH patients,the more obvious formation of sclerosis rim.The expression of BMP in femoral head was changed according to different etiology,age and sclerosis rim grading,wich could be used as experimental and theoretical basis on personalized treatment for ONFH patitents.