The Experimental Study On The Pre-early Diagnosis Of Osteonecrosis Of Femoral Head

Objective:Diffusion weighted magnetic resonance imaging(DWI),in combination with conventional magnetic resonance imaging,histopathological and hematological examination were used to assess internal environment changes of the femoral head in the pre-early stage of osteonecrosis of femoral head and to explore the application perspective of DWI in the pre-early diagnosis of ONFH in animal model.Methods:12 healthy beagles were randomly divided into two groups,2 for control group and the remaining 10 for experimental group.The experimental group was injected lipopolysaccharide 10μg/kg and methylprednisolone 20 mg/kg for three consecutive days;the control group was injected Normal Saline as control.2 months and 4 months after administration,control group and experimental group were performed MRI and DWI examination,and the apparent diffusion coefficient(ADC)values of the weight-bearing area of the femoral head were calculated according to DWI.One and five animals of two groups were killed respectively 2 months and 4 months after administration and bilateral femoral head specimens were obtained to perform histopathological examination.In control group and experimental group, prothrombin time(PT),activated partial thromboplastin time (APTT),antithrombin-Ⅲ(AT-Ⅲ) were tested before and 24 hour after administration.Results:IN the experimental group,the histopathological results showed that there are 4 osteonecrosis of femoral head at 2 months after administration which showed bone trabeculae thinning,some disruption of bone trabeculae,an increase in the number of empty lacunae and MRI and DMI did not show any abnormality.The histopathological results showed that there are 6 osteonecrosis of femoral head at 4 months after administration which showed disruption of bone trabecular,osteoblasts can be seen around a small number of trabecular bone necrosis,fibrovascular tissue repair can be seen around some of the necrotic foci and MRI and DMI did not show any abnormality.The ADC value of the weight-bearing area of ONFH of the experimental group was 5.7±0.2×10-4mm~2/s,whereas the ADC value of the corresponding area of non-ONFH of the experimental group and control group was 3.5±0.4×10-4mm~2/s.There was a significant difference between them(P＜0.05).The ADC value of the weight-bearing area of osteonecrosis of femoral head of the experimental group was 5.70±0.21×10-4mm~2/s at 2 months after administration. The ADC value of the weight-bearing area of osteonecrosis of femoral head of the experimental group was 5.72±0.17×10-4mm~2/s at 4 months after administration.There was no significant difference between them(P＞0.05)。There is no significant change in hematological examination before and after administration in the control group.In the experimental group,the PT,APTT,AT-Ⅲdrop after administration and there is significant difference comparing with that before administration(P＜0.05).Conclusion:The method of intramuscular injection of LPS and Methylprednisolone in beagls can lead to osteonecrosis of femoral head.Hypercoagulation and low fibrinolysis may be the reason of steroid-induced osteonecrosis.In the pre-early stage of osteonecrosis of femoral head when there is no obvious abnormal change in magnetic resonance imaging,the local elevated apparent diffusion coefficient value of femoral head may have some significance and possess potential application prospective to the pre-early diagnosis of osteonecrosis of femoral head Objective:To detect blood perfusion of the necrotic area and the femoral head and neck junction in the patients who have been diagnosed as osteonecrosis of femoral head(ONFH) with LDF.Methods:From 2007 to 2008,82 hips of 50 patients with ONFH who will be performed core decompression and autologous stem cells transplantation(Group A is for ARCO stageⅡ46 hips(ⅡA 6 hips,ⅡB22 hips,ⅡC18 hips),group B is for stageⅢ36 hips(ⅢA20hips,ⅢB10hips,ⅢC6 hips)) were detected the blood perfusion of necrotic area and femoral head and neck junction with LDP during the operationn.Making statistical analysis on the data.Results:In Group A,the perfusion volume of necrotic area is 30.20±3.05PU,the perfusion volume of femoral head and neck junction is 103.38±4.38PU.In Group B,the perfusion volume of necrotic area is 30.62±2.85PU,the perfusion volume of femoral head and neck junction is 103.35±3.91PU.In Group A and Group B,the perfusion volume of necrotic area was lower than that of femoral head and neck junction and there were significant differences between them(P＜0.01=.There were no significant differences between Group A and Group B(P＞0.01).Conclusions:LDF can effectively detect that the perfusion volume of ONFH decreased,which provided a theoretical basis in order to further study the pathogenesis of ONFH.Meanwhile,there is application value of LDF on the study of ONFH.