【Abstract】 Objective To approach the possibil ity of combination of simvastatin and BMSCs transplantation forsteroid-associated osteonecrosis of femoral head. Methods The BMSCs harvested from 24 rabbits were prepared for cell suspension at a concentration of 1 × 107/mL, and combined with gelatin sponge. Seventy New Zealand white rabbits received one intravenous injection of l ipopolysaccharide (10 μg/ kg). After 24 hours, three injections of 20 mg/kg of methylprednisolone were given intramuscularly at a time interval of 24 hours. Forty-eight rabbits diagnosed as having femoral head necrosis by MRI were divided into 4 groups randomly, group A: no treatment; group B: only decompression; group C: decompression and BMSCs transplantation; and group D: simvastatin drench (10 mg/kg.d) decompression and BMSCs transplantation. The general information of animals were recorded; after 4 and 8 weeks of operation, 6 rabbits of each group were chosen randomly to do MRI scan, and femoral heads were harvested to do histopathology and scanning electron microscope examination. Results After 8 weeks, rabbits became more active than before treatment, and walking way became normal gradually in groups C and D. Fourweeks after operation, the MRI low signal region of all groups had no obvious changes, but 8 weeks later, the necrosis signal region of group A magnified while it reduced obviously in group D. Histopathological observation: 4 weeks after operation, diffuse presence of empty lacunae and pyknotic nuclei of osteocytes were found in the trabeculae, and few newborn micrangium could been seen in group A; lots of empty lacunae and a small quantity of newborn micrangium could been found in group B; and large amounts of osteoblats and newborn micrangium were found around the necrosis regions in groups C and D. The positive ratio of empty lacunae and microvessel density in group D were 19.30 ± 1.52 and 7.08 ± 1.09, showing significant difference compared with other groups (P lt; 0.05). After 8 weeks of treatment, the bone trabecula collapsed in many regions in group A; there was fibra callus formation along the decompression channel in group B; few empty lacunae was in the bone trabecular, but the shape of marrow cavity was not normal in group C; and it showed almost normal appearance in group D. The positive ratio of empty lacunae and microvessel density in group D were 11.31 ± 1.28 and 12.37 ± 1.32, showing significant differences compared with other groups (P lt; 0.05), meanwhile, showing significant difference compared with that of 4 weeks after operation(P lt; 0.05). Scanning electron microscope: 8 weeks after operation, the bone trabecula collapsed in many regions, and few osteoblasts could be found on the surface, a great quantity of fat cells cumulated in the bone marrow in group A; cracked bone trabecula could be found occasionally in group B; the density of bone trabecula was lower than the normal in group C; and the shape of the marrow avity and thedensity of bone trabecula were similar to the normal in group D. Conclusion Simvastatin can promote the differentiation of osteocyte and vascular endothel ial cell from MSCs, the combination of simvastatin and marrow stem cells transplantation for the treatment of steroid-associated osteonecrosis of femoral head have good appl ication prospects.
Objective To investigate diagnosis and surgical management of femoral head osteonecrosis in sickle cell disease(SCD). Methods The related literature available today was reviewed, and the clinical advance in the diagnosis of femoral head osteonecrosis complicating SCD and its surgical management was evaluated. Results Although the advance in the diagnosisand the surgical treatment for the femoral head osteonecrosis in SCD had been achieved, challenging clinical problems still remained because of many complications after the surgical treatment. Whether the surgical management was reasonablein a particular stage of the disease and for a specific patient still required investigation. Conclusion Whether the salvage of the patient’ship joint should be performed or the artificial joint replacement should be performed still needs a cautious consideration before either of the surgical managements is given.
Objective To evaluate the correlation between pelvic incidence (PI) angle, hip deflection angle (HDA), combined deflection angle (CDA) and osteonecrosis of the femoral head (ONFH) after femoral neck fracture, in order to explore early predictive indicators for ONFH occurrence after femoral neck fracture. Methods A study was conducted on patients with femoral neck fractures who underwent cannulated screw internal fixation between December 2018 and December 2020. Among them, 208 patients met the selection criteria and were included in the study. According to the occurrence of ONFH, the patients were allocated into ONFH group and non-NOFH group. PI, HDA, and CDA were measured based on the anteroposterior X-ray films of pelvis and axial X-ray films of the affected hip joint before operation, and the differences between the two groups were compared. The receiver operating characteristic curve (ROC) was used to evaluate the value of the above imaging indicators in predicting the occurrence of ONFH. ResultsAmong the 208 patients included in the study, 84 patients experienced ONFH during follow-up (ONFH group) and 124 patients did not experience ONFH (non-ONFH group). In the non-ONFH group, there were 59 males and 65 females, the age was 18-86 years (mean, 53.9 years), and the follow-up time was 18-50 months (mean, 33.2 months). In the ONFH group, there were 37 males and 47 females, the age was 18-76 years (mean, 51.6 years), and the follow-up time was 8-45 months (mean, 22.1 months). The PI, HDA, and CDA were significantly larger in the ONFH group than in the non-ONFH group (P<0.05). ROC curve analysis showed that the critical value of PI was 19.82° (sensitivity of 40.5%, specificity of 86.3%, P<0.05); the critical value of HDA was 20.94° (sensitivity of 77.4%, specificity of 75.8%, P<0.05); and the critical value of CDA was 39.16° (sensitivity of 89.3%, specificity of 83.1%, P<0.05). Conclusion There is a correlation between PI, HDA, CDA and the occurrence of ONFH after femoral neck fracture, in which CDA can be used as an important reference indicator. Patients with CDA≥39.16° have a higher risk of ONFH after femoral neck fracture.
ObjectiveTo explore the effect of Kaempferol on bone microvascular endothelial cells (BMECs) in glucocorticoid induced osteonecrosis of the femoral head (GIONFH) in vitro. MethodsBMECs were isolated from cancellous bone of femoral head or femoral neck donated voluntarily by patients with femoral neck fracture. BMECs were identified by von Willebrand factor and CD31 immunofluorescence staining and tube formation assay. The cell counting kit 8 (CCK-8) assay was used to screen the optimal concentration and the time point of dexamethasone (Dex) to inhibit the cell activity and the optimal concentration of Kaempferol to improve the inhibition of Dex. Then the BMECs were divided into 4 groups, namely, the cell group (group A), the cells treated with optimal concentration of Dex group (group B), the cells treated with optimal concentration of Dex+1 μmol/L Kaempferol group (group C), and the cells treated with optimal concentration of Dex+5 μmol/L Kaempferol group (group D). EdU assay, in vitro tube formation assay, TUNEL staining assay, Annexin Ⅴ/propidium iodide (PI) staining assay, Transwell migration assay, scratch healing assay, and Western blot assay were used to detect the effect of Kaempferol on the proliferation, tube formation, apoptosis, migration, and protein expression of BMECs treated with Dex. ResultsThe cultured cells were identified as BMECs. CCK-8 assay showed that the optimal concentration and the time point of Dex to inhibit cell activity was 300 μmol/L for 24 hours, and the optimal concentration of Kaempferol to improve the inhibitory activity of Dex was 1 μmol/L. EdU and tube formation assays showed that the cell proliferation rate, tube length, and number of branch points were significantly lower in groups B-D than in group A, and in groups B and D than in group C (P<0.05). TUNEL and Annexin V/PI staining assays showed that the rates of TUNEL positive cells and apoptotic cells were significantly higher in groups B-D than in group A, and in groups B and D than in group C (P<0.05). Scratch healing assay and Transwell migration assay showed that the scratch healing rate and the number of migration cells were significantly lower in groups B-D than in group A, and in groups B and D than in group C (P<0.05). Western blot assay demonstrated that the relative expressions of Cleaved Caspase-3 and Bax proteins were significantly higher in groups B-D than in group A, and in groups B and D than in group C (P<0.05); the relative expressions of matrix metalloproteinase 2, Cyclin D1, Cyclin E1, VEGFA, and Bcl2 proteins were significantly lower in groups B-D than in group A, and in groups B and D than in group C (P<0.05). Conclusion Kaempferol can alleviate the damage and dysfunction of BMECs in GIONFH.
ObjectiveTo explore the risk factors for osteonecrosis of the femoral head (ONFH) after treatment of femoral neck fractures with femoral neck system (FNS). MethodsBetween January 2020 and February 2021, 179 patients (182 hips) with femoral neck fractures treated by FNS fixation were selected for retrospective analysis. There were 96 males and 83 females with an average age of 53.7 years (range, 20-59 years). There were 106 cases of low-energy-induced injury and 73 cases of high-energy-induced injury. The fractures were classified as type Ⅱ in 40 hips, type Ⅲ in 78 hips, and type Ⅳ in 64 hips according to Garden classification standard, and as typeⅠin 23 hips, type Ⅱ in 66 hips, and type Ⅲ in 93 hips according to Pauwels classification standard. There were 21 patients with diabetes. Patients were divided into ONFH group and non-ONFH group according to whether ONFH occurred at last follow-up. The data of the patients were collected, including age, gender, body mass index (BMI), trauma mechanism, bone mineral density, having diabetes or not, Garden classification and Pauwels classification of fractures, fracture reduction quality, femoral head retroversion angle, and removal of internal fixator or not. The above factors were analyzed by univariate analysis, and then multivariate logistic regression analysis was used to identify risk factors. Results Total 179 patients (182 hips) were followed up 20-34 months (mean, 26.5 months). Of these, 30 cases (30 hips) developed ONFH at 9-30 months after operation (ONFH group), and the incidence of ONFH was 16.48%. And 149 cases (152 hips) had no ONFH at last follow-up (non-ONFH group). The univariate analysis showed that there were significant differences between groups in bone mineral density, having diabetes or not, Garden classification, femoral head retroversion angle, and fracture reduction quality (P<0.05). The multivariate logistic regression analysis showed that the Garden type Ⅳ fracture, reduction quality of grading Ⅲ, femoral head retroversion angle >15°, complicated with diabetes were the risk factors for ONFH after FNS fixation (P<0.05). ConclusionFor the patients with Garden type Ⅳ fracture, poor quality of fracture reduction, femoral head retroversion angle >15°, and diabetes, the risk of ONFH after FNS fixation increases.
Objective To review the research progress of alcohol-induced osteonecrosis of the femoral head (ONFH). Methods Recent literature concerning alcohol-induced ONFH was reviewed and summarized. Results Alcohol-induced ONFH accounte for approximately 1/3 of total ONFH. Alcohol intake and the incidence of ONFH has a significant dose-effect relationship. There are some correlations between alcohol-induced ONFH and lipid metabolism, secretion of corticosteroid, and some gene of alcohol or lipid metabolism. Conclusion The relationships between alcohol and lipid metabolism, and between alcohol and steroid are still the main direction of the research of ONFH. Gene level researches can not demonstrate the pathogenesis, therefore further research should be carried on.
ObjectiveTo screen for the differentially expressed genes in steroid-induced osteonecrosis of the femoral head (ONFH) by gene microarray. MethodsThe femoral head tissue of ONFH was harvested from 3 patients with steroid-induced ONFH, aged 25, 31, and 38 years, respectively. Normal tissue was harvested from a 26-year-old male remains contributor. HE staining of the specimens was performed for observing the histology manifestation; the total RNA was extracted for measuring the purity; cDNA probe was synthesized by reverse transcription, and then were hybridized as the cDNA microarray for scanning of fluorescent signals and differentially expressed genes in the tissues. ResultsHE staining of normal tissue showed complete unit composed of lamellar bone, continuous and complete lamellar bone with a concentric arrangement around blood vessels, and normal bone cells in the trabecular bone lacuna. In ONFH tissue, adipose tissue increased in the medullary cavity, with increased fat cells filling in the medullary cavity and extruding capillary, and with decreased bone cells in the bone trabecula, which had deeply-stained nuclear chromatin, pyknotic or cracking nucleus, and even bone cells disappeared in the part of the bone lacuna, and trabecular bone became thin, sparse, interrupt, reduced area in visual field/unit. Total RNA extraction electrophoretogram displayed clear bands of 28S and 18S, and the brightness ratio of the 28S:18S was 2:1, indicating good total RNA quality. And 44 genes were differentially expressed, and there were 28 up-regulated genes and 16 down-regulated genes, including cell/organism defense genes, cell structure/motility genes, cell division genes, cell signaling/cell communication genes, cell metabolism genes, gene/protein expression genes, and unclassified genes. ConclusionThe analysis of the gene expression profile of steroid-induced ONFH can provide evidence for the pathogenesis of ONFH.
There are two main types of fluid in bone tissue: blood and interstitial fluid. The metabolism of cells mainly relies on the microenvironment of the interstitial fluid. Researches of osteonal fluid seepage behavior based on the microstructure of bone tissue have become a hot point. The aim of the present research work is to assess the effect of blood pressure oscillation on the osteonal interstitial fluid seepage behavior. We established finite element osteon models for a hollow and that considering blood pressure oscillation, respectively, with COMSOL Multiphysics software in order to compare their fluid flow behavior under the axial loading. The results predicted that the interstitial fluid pressure field was enlarged considering the blood pressure oscillation, while the velocity filed changed little. Specifically, the increase of blood pressure oscillatory amplitude could result in the increase of osteonal interstitial fluid pressure, while the blood pressure oscillatory frequency had limited effects on the osteonal pore fluid pressure. Moreover, the blood pressure oscillatory amplitude and frequency had no effect on the osteonal interstitial fluid velocity. The finite element model can be used for the study of the poroelastic behaviors of the osteon under non-axisymmetric loads and microcracks, and can also be a new way to study the mechanism of bone mechanotransduction and electromechanotransduction.
Objective To explore the impact of preoperative traction on the osteonecrosis of the femoral head (ONFH) in patients with femoral neck fractures. Methods Between February 2013 and May 2016, 120 patients with femoral neck fractures, who were treated with screw fixation, were collected. Sixty patients with fractures of Garden type Ⅰ and Ⅱ were non-displaced fracture group; 60 cases with fractures of Garden type Ⅲ and Ⅳ were displaced fracture group. The patients in 2 groups were randomly divided into traction and non-traction subgroups (n=30). There was no significant difference in gender, age, injury mechanism, damage side, the time from injury to operation, and fracture classification between 2 subgroups (P>0.05). Intracapsular pressure was recorded before operation. The quality of fracture reduction and the satisfaction ratio of screw implant were evaluated during operation. Visual analogue scale (VAS), Harris score, joint mobility, and the incidence of ONFH would be evaluated at 6 months, 1 year, and 2 years after operation. Results All incisions of 2 groups healed by first intention after operation. There was no infection or deep vein thrombosis of lower extremity. All patients were followed up 2 years. In displaced and non-displaced fracture groups, the intracapsular pressure of traction subgroups were higher than that of non-traction group (P<0.05); the differences of the quality of fracture reduction and the satisfaction ratio of screw implant were not significant (P>0.05) between 2 subgroups. At 6 months, 1 year, and 2 years after operation, VAS scores were higher in traction subgroup than in non-traction subgroup (P<0.05); and the joint mobility and Harris scores were lower in traction subgroup than in non-traction subgroup (P<0.05). X-ray films showed all fractures healed. Except for the non-displaced group at 6 months, the incidences of ONFH were higher in traction subgroup than in non-traction subgroup at other time points (P< 0.05). Conclusion Preoperative traction may increase the risk of ONFH, which can increase the intracapsular pressure and affect the blood supply of femoral head.
Objective To explore the significance of osteocyte apoptosis in steroidinduced osteonecrosis of the femoral head. Methods SixtyNew Zealand rabbits were divided into experimental group and control group(n=30). The experimental group was given 10 ml/kg of horse serum intravenously 2 times at 2 weeks intervals and an intraperitoneal injection of 45 ml/kg·d of methylprednisolone acetate for 3 days；the control group was given equal isotonic Na chloride. Osteocyteapoptosis was observe by means of TUNEL. Results The number of apoptosis in the experimental group(112.33‰±26.12‰) was significantly higher than that in the control(47.01‰±22.95‰) (Plt;0.01)in the 4th week. With time, osteocytes apoptosis progressively increased. In the 6thand 8th weeks, the percentage of empty osteocyte lacunae in the experimental group (17.23%±3.44%, 28.56%±3.45%) was significantly higher than that in the control group (11.29%±2.89%,11.26%±2.75%，Ｐlt;0.05). The transmission electron microscope showed that the characteristics of osteocyte apoptosisincluded intact nuclear membrane,comdensed chromatin and increased electron dense. Conclusion Osteocytes apoptosis may play a key role in the process of steroidinduced early osteonecrosis of the femoral head.