Steroid-associated Osteonecrosis Research Articles

Promotion of bone repair by implantation of cryopreserved bone marrow–derived mononuclear cells in a rabbit model of steroid‐associated osteonecrosis

Cytotherapy is an insufficient method for promoting bone repair in steroid-associated osteonecrosis (SAON), and this has been attributed to impairment of the bioactivity of bone marrow-derived stem cells (BMSCs) after pulsed administration of steroids. Cryopreserved autologous bone marrow-derived mononuclear cells (BMMNCs), which contain BMSCs, might maintain their bioactivity in vitro. This study sought to investigate the effects of cryopreserved BMMNCs, before steroid administration, on the enhancement of bone repair in an established rabbit model of SAON. For in vitro study, bone marrow was harvested 4 weeks before SAON induction from the iliac crests of rabbits (n = 10) to isolate fresh BMMNCs, and the BMMNCs were then cryopreserved for 8 weeks. Both the fresh and the cryopreserved BMMNCs were evaluated for their bioactivity and osteogenic differentiation capacity. In addition, BMMNCs were isolated 2 weeks after SAON induction and subjected to the same evaluations. For in vivo study, cryopreserved BMMNCs were implanted into the bone tunnel during core decompression of the femur (n = 12 rabbits) after the induction of SAON, and tissue regeneration was evaluated by micro-computed tomography and histologic analyses at 12 weeks postoperation. In vitro, there were no significant differences in the bioactivity or ability to undergo osteogenic differentiation between fresh BMMNCs and cryopreserved BMMNCs, but after SAON induction, both features were decreased significantly. In vivo, the bone mineral density, ratio of bone volume to total volume of bone, and volume and diameter of neovascularization within the bone tunnel were significantly higher in the BMMNC-treated group compared to the nontreated control group at 12 weeks postoperation. Cryopreserved BMMNCs maintained their bioactivity and promoted bone regeneration and neovascularization within the bone tunnel after core decompression in this rabbit model of SAON.

The incidence of alcohol-associated osteonecrosis of the knee is lower than the incidence of steroid-associated osteonecrosis of the knee: an MRI study

The purpose of the study was to clarify the incidence of alcohol-associated osteonecrosis of the knee using MRI. A total of 131 patients (56 women and 75 men) with osteonecrosis of the femoral head were enrolled; 60 patients had a history of alcohol abuse and 71 had previously received steroids. All patients underwent MRI of the knee. The incidence of alcohol-associated osteonecrosis of the knee was compared with that of steroid-associated osteonecrosis of the knee. Predictive factors of alcohol- and steroid-associated osteonecrosis of the knee were also evaluated. The incidence of alcohol-associated osteonecrosis of the knee was lower than that of steroid-associated osteonecrosis of the knee (18.3 vs 54.9%; P < 0.001, Fisher's exact probability test). No significant difference in weekly alcohol consumption was observed between patients with osteonecrosis of the knee and those without osteonecrosis of the knee. No significant difference in daily maximum steroid doses was observed between patients with osteonecrosis of the knee and those without osteonecrosis of the knee. The present study revealed that the incidence of alcohol-associated osteonecrosis of the knee is lower than that of steroid-associated osteonecrosis of the knee.

Metabolism of Epimedium-derived Flavonoid Glycosides in Intestinal Flora of Rabbits and Its Inhibition by Gluconolactone

Aim The metabolism of Epimedium-derived flavonoid glycosides (EF, with icariin as the main component) in rabbit intestinal flora and its inhibition by gluconolactone were investigated in this paper to help reveal the metabolic pathway of EF in rabbits and to identify the in vivo bioactive components of EF in the prevention of steroid-associated osteonecrosis. Methods EF were incubated at 37 °C anaerobically with rabbit intestinal flora, and then water-saturated ethyl acetate was used for sample extraction at different time points. Furthermore, gluconolactone was added at different concentrations (8, 12 and 16 mg·mL −1) to study its inhibition of the metabolism of EF in rabbit intestinal flora. The separation was performed on a ODS column by gradient elution with acetonitrile-water (including 0.1% formic acid respectively) as mobile phase at detection wavelength of 335 nm. Results EF were metabolized to icariside II in 2 h, and then to icaritin when incubated for 8 h; gluconolactone showed the inhibition of EF metabolism in rabbit intestinal flora in a concentration-dependent manner. Conclusion EF were found to be metabolized rapidly by hydrolysis of rabbit intestinal flora to produce icariside II and icaritin; and the total inhibition was achieved by gluconolactone at a concentration of 16 mg·mL −1.

Incidence of osteonecrosis associated with corticosteroid therapy among different underlying diseases: prospective MRI study

The purpose of this study was to clarify the incidence of (CS)-associated osteonecrosis among different underlying diseases and to evaluate the risk factors for steroid-associated osteonecrosis in a prospective MRI study. We prospectively used MRI to study 337 eligible underlying disease patients requiring CS therapy and succeeded in examining 1199 joints (hips and knees) in 302 patients with MRI for at least 1 year starting immediately after the onset of CS therapy (1-year follow-up rate of 90%). The underlying diseases included SLE in 687 joints (173 patients) and a variety of other rheumatological disorders in 512 joints (129 patients). The incidence of osteonecrosis was significantly higher in SLE patients than in non-SLE patients (37 vs 21%, P = 0.001). Logistic regression analysis revealed that adolescent and adult patients had a significantly higher risk of osteonecrosis compared with paediatric patients [odds ratio (OR) = 13.2], that high daily CS dosage (>40 mg/day) entailed a significantly higher risk of osteonecrosis compared with the dosage of <40 mg/day (OR = 4.2), that SLE patients had a significantly higher risk of osteonecrosis compared with non-SLE patients (OR = 2.6) and that male patients had a significantly higher risk of osteonecrosis compared with female patients (OR = 1.6). These findings suggest that the incidence of CS-associated osteonecrosis varies among different underlying diseases.

Impaired bone healing in rabbits with steroid-induced osteonecrosis

Corticosteroids are prescribed for the treatment of many medical conditions and their adverse effects on bone, including steroid-associated osteoporosis and osteonecrosis, are well documented. Core decompression is performed to treat osteonecrosis, but the results are variable. As steroids may affect bone turnover, this study was designed to investigate bone healing within a bone tunnel after core decompression in an experimental model of steroid-associated osteonecrosis. A total of five 28-week-old New Zealand rabbits were used to establish a model of steroid-induced osteonecrosis and another five rabbits served as controls. Two weeks after the induction of osteonecrosis, core decompression was performed by creating a bone tunnel 3 mm in diameter in both distal femora of each rabbit in both the experimental osteonecrosis and control groups. An in vivo micro-CT scanner was used to monitor healing within the bone tunnel at four, eight and 12 weeks postoperatively. At week 12, the animals were killed for histological and biomechanical analysis. In the osteonecrosis group all measurements of bone healing and maturation were lower compared with the control group. Impaired osteogenesis and remodelling within the bone tunnel was demonstrated in the steroid-induced osteonecrosis, accompanied by inferior mechanical properties of the bone. We have confirmed impaired bone healing in a model of bone defects in rabbits with pulsed administration of corticosteroids. This finding may be important in the development of strategies for treatment to improve the prognosis of fracture healing or the repair of bone defects in patients receiving steroid treatment.

Beneficial Effect of Autologous Transplantation of Endothelial Progenitor Cells on Steroid-Induced Femoral Head Osteonecrosis in Rabbits

Femoral head osteonecrosis (ON) is a serious complication of steroid administration. We examined whether implantation of autologous bone marrow-derived endothelial progenitor cells (EPCs) can augment neovascularization and bone regeneration in steroid-induced osteonecrosis of the femoral head. Forty 12-week-old male New-Zealand white rabbits were divided into group I (left untreated, n=12), group II (core decompression, n=12), and group III (core decompression + autologous EPCs implantation, n=16) after receiving an established inductive protocol for inducing steroid-associated ON. Four weeks later, these rabbits were euthanized, bilateral femora were dissected for Micro-CT-based microangiography to assess vascularization, and then the osteonecrotic changes and repair processes were examined histopathologically. Quantitative analysis showed that new vessel formation in group III was significantly greater compared with other groups at 4 weeks after treatment. The histologic and histomorphometric analyses revealed that the new bone volume was significantly higher in group III than in groups I and II 4 weeks after treatment. A combination of EPCs and core decompression enhances the neovascularization and bone regeneration in rabbit steroid-induced femoral head ON. Local implantation of EPCs may provide a novel and effective therapeutic option for early corticosteroid-induced ON.

Thorough Debridement of the Humeral Head for Osteonecrosis

Osteonecrosis of the shoulder is a devastating disease, particularly in the young patient. Published data is replete with vascularized and nonvascularized bone grafting procedures for joint preservation of the hip; however, these same techniques have not been applied to the shoulder. When treating osteonecrosis of the shoulder, endoscopically-guided thorough debridement of the necrotic bone may promote good outcomes by ensuring that the bone graft, vascularized or nonvascularized, is stabilized against a viable host bed. In addition, this new technique facilitates access to the subchondral plate from the osseous side, thereby fully debriding the intraosseous fracture and allowing elevation of the articular surface if needed. When collapse is present, stage 3 disease secondary articular-sided changes may be present and should be addressed during concomitant arthroscopy. This article presents a case of endoscopically-guided thorough debridement of the humeral head combined with nonvascularized bone grafting of the residual cavity and stabilization, and concomitant arthroscopy for a 30-year-old woman with steroid-associated osteonecrosis.

Phytoestrogenic herbal Epimedium-derived bioactive compound icariin reduces the incidence of steroid-associated osteonecrosis in rabbits

Phytoestrogenic herbal Epimedium-derived bioactive compound icariin reduces the incidence of steroid-associated osteonecrosis in rabbits

Continuous occurrence of both insufficient neovascularization and elevated vascular permeability in rabbit proximal femur during inadequate repair of steroid‐associated osteonecrotic lesions

To examine the features of the intraosseous vasculature, the size of the marrow stem cell pool (MSCP), and expression of vascular endothelial growth factor A (VEGF) during inadequate repair of steroid-associated osteonecrotic lesions in rabbits. Steroid-associated osteonecrosis was induced in male rabbits. At 0, 1, 2, 4, and 6 weeks postinduction, vascularization and permeability indices were quantified by dynamic magnetic resonance imaging (MRI). In addition, the size of the MSCP in the hematopoietic and mesenchymal compartments was determined, and marrow mononuclear cells expressing specific surface markers for endothelial progenitor cells or periendothelial mural precursor cells were counted. At various time points after the rabbits were killed, the proximal femora were dissected to examine the intraosseous vasculature by angiography, histomorphometry, and ultramorphology. In addition, osteonecrotic lesion repair and marrow VEGF expression were evaluated. Lesion formation without repair was observed at 2 weeks after induction of steroid-associated osteonecrosis. Rabbits displaying destructive repair (DR+) and those displaying reparative osteogenesis (DR-) from 4 weeks to 6 weeks postinduction were identified. From week 2 to week 6, the vascularization index was significantly lower in DR+ rabbits compared with DR- rabbits, whereas the permeability index was significantly higher in DR+ rabbits compared with DR- rabbits. The features of the intraosseous vasculature determined by angiography, histomorphometry, and ultramorphology were consistent with those determined by dynamic MRI. The MSCP size and number of marrow mononuclear cells expressing specific surface markers were all significantly lower in DR+ rabbits than in DR- rabbits from week 1 to week 6. The increased VEGF expression at 2 weeks was maintained through week 6 in DR+ rabbits, whereas VEGF expression decreased in DR- rabbits from week 2 to week 6. Continuous occurrence of both insufficient neovascularization and elevated vascular permeability is accompanied by a continuously low- level MSCP and uncontrolled VEGF expression during inadequate repair of steroid-associated osteonecrotic lesions.

Constitutional Flavonoids Derived from Epimedium Dose-Dependently Reduce Incidence of Steroid-Associated Osteonecrosis Not via Direct Action by Themselves on Potential Cellular Targets

Intravascular-thrombosis and extravascular-lipid-deposit are the two key pathogenic events considered to interrupt intraosseous blood supply during development of steroid-associated osteonecrosis (ON). However, there are no clinically employed agents capable of simultaneously targeting these two key pathogenic events. The present experimental study demonstrated that constitutional flavonoid glycosides derived from herb Epimedium (EF, composed of seven flavonoid compounds with common stem nuclear) exerted dose-dependent effect on inhibition of both thrombosis and lipid-deposition and accordingly reducing incidence of steroid-associated ON in rabbits, which was not via direct action by themselves rather by their common metabolite on potential cellular targets involved in the two pathogenic pathways. The underlying mechanism could be explained by counteracting endothelium injury and excessive adipogenesis. These findings encourage designing clinical trials to investigate potential of EF in prevention of steroid-associated ON.

In vitro release of osteoinductive molecule Icaritin from porous PLGA/TCP/Icaritin scaffolds for repairing steroid-associated osteonecrosis lesion

In vitro release of osteoinductive molecule Icaritin from porous PLGA/TCP/Icaritin scaffolds for repairing steroid-associated osteonecrosis lesion

Promotion of tissue repair of steroid-associated osteonecrosis lesion in rabbits by using PLGA/TCP/Icaritin composite biomaterials scaffold: An in vivo micro-computed tomography study

Promotion of tissue repair of steroid-associated osteonecrosis lesion in rabbits by using PLGA/TCP/Icaritin composite biomaterials scaffold: An in vivo micro-computed tomography study

Functional perfusion MRI predicts later occurrence of steroid‐associated osteonecrosis: An experimental study in rabbits

Ischemia is the defined pathway leading to steroid-associated osteonecrosis (ON). Early detection of ischemic condition may help predict later ON occurrence. Bone marrow perfusion function evaluation by perfusion magnetic resonance imaging (MRI) may be a unique modality for this application. Twenty-five adult male New Zealand white rabbits were used in this study. Lipopolysaccharide (LPS) and methylprednisolone (MPS) were administrated for ON induction based on a published protocol. T1-weighted and fat suppression T2-weighted MR imaging (conventional MRI) were performed for ON lesion detection based on the abnormal signal in the proximal femora at week 0 as the baseline (before LPS injection), and week 1 and week 2 after MPS injection. At the same time, the blood perfusion function in the proximal femora was measured by perfusion MRI. Maximum enhancement (ME)--an index of MRI perfusion function was analyzed. After MRI scanning, the proximal femora were prepared histopathologically for ON lesion analysis. The rabbit with bilateral histopathological ON lesions was defined as an ON+ rabbit and included in the ON+ group evaluated at week 1 and week 2, respectively, and the rabbit without ON lesions in bilateral femora was classified into the ON- group. For the underlying mechanism of perfusion change, the extravascular marrow fat cells were measured and the intravascular endothelium inflammation injury indicator of tissue factor (TF) expression and thrombus formation were detected. In ON+ group, ME in perfusion MRI showed a significant decrease at week 1 and week 2 as compared with the baseline (p < 0.01). There was a more than 50% decrease in ME at week 1 in ON+ group; whereas there were no detectable ON lesions by conventional MRI at week 1, though 93% (14/15) rabbits could be detected at week 2 in ON+ group. In ON- group, ME showed a slight decrease at week 1 (less than 30%), and nearly recovered to normal at week 2 as compared with the baseline. Histological results showed a much larger average marrow fat area and more severe marrow blood sinusoids compression from surrounding crowded fat cells, and stronger positive TF expression in marrow endothelium and more thrombus formation in ON+ rabbits than ON- rabbits. This study demonstrated that functional perfusion MRI could predict development of steroid-associated ON. Our experimental data suggested that perfusion MRI might be a sensitive noninvasive modality for monitoring steroid-associated ON in patients.

A Combination of Granulocyte Colony-Stimulating Factor and Stem Cell Factor Ameliorates Steroid- Associated Osteonecrosis in Rabbits

Bone marrow-derived stem cells (BMSC) have been highlighted for the treatment of osteonecrosis (ON) before collapse of the femoral head. In our study, the potential of granulocyte colony-stimulating factor/stem cell factor (G-CSF/SCF)-mobilized BMSC to repair steroid-associated ON was assessed in rabbits. ON was induced by low-dose lipopolysaccharide and subsequent pulsed high-dose methylprednisolone. Rabbits in the treated group were subjected to subcutaneous injections of G-CSF at a dose of 100 microg/kg and SCF 25 microg/kg per day for 5 days; rabbits in the control group were given saline. Blood samples were collected and serum osteocalcin was detected by ELISA. Radiological analysis was performed by magnetic resonance imaging (MRI). Then bilateral femora and humeri were harvested and processed to paraffin sections and hard-tissue sections for immunohistochemical, histologic, and histomorphometric analysis. . The mean number of leukocytes and relative numbers of mononuclear cells increased significantly after mobilization. All rabbits displayed a marked increase in osteocalcin protein expression in response to G-CSF/SCF. MRI scans showed a reactive interface between the necrotic and reparative zones after G-CSF/SCF administration. Quantitative analysis showed that new vessel formation was 3.3-fold greater and vessel density was 2.6-fold greater in the treatment group than the control group. The histologic and histomorphometric analysis revealed that the new bone volume was significantly higher in the G-SCF/SCF group than in the control group at 4 weeks. G-CSF/SCF-induced mobilization of BMSC in the necrotic foci may represent a promising strategy for promoting functional bone repair of early-stage ON.

A novel semisynthesized small molecule icaritin reduces incidence of steroid-associated osteonecrosis with inhibition of both thrombosis and lipid-deposition in a dose-dependent manner

Background Intravascular-thrombosis and extravascular-lipid-deposition are the two key pathogenic events considered to interrupt intraosseous blood supply during steroid-associated osteonecrosis (ON) development. However, there are no reported candidate agents capable of simultaneously targeting these two key pathogenic events. The authors' published experimental studies have shown that Epimedium-derived flavonoids possess an anti-ON effect. Further, the authors have recently identified a small molecule Icaritin as an intestinal metabolite of Epimedium-derived flavonoids. Objective The present study was to evaluate the prevention effect of the available semisynthesized small molecule Icaritin on steroid-associated ON development in a rabbit model. Methods After receiving an established inductive protocol for inducing steroid-associated ON, eighty-four male 28-week-old New-Zealand white rabbits were divided into the following three daily oral administration groups, including low dose Icaritin group (L-ICT; n = 28; 5 mg·kg − 1 ·day − 1 ), high dose Icaritin group (H-ICT; n = 28; 10 mg·kg − 1 ·day − 1 ), and control vehicle group (CON; n = 28). Before and after induction, dynamic contrast-enhanced MRI was performed on proximal femur for intra-osseous perfusion function index. Meanwhile, blood samples were examined for coagulation, fibrinolysis, lipid-transportation, endothelium injury, oxidative stress, and hepatocyte injury index, while marrow samples were quantified for adipogenic potential index of mesenchymal stem cell by in vitro culture and proliferator-activated receptor-gamma (PPARgamma) protein expression by western blot. At baseline, week 1 and 2 post-induction, 4, 8 and 16 rabbits in each group were sacrificed, respectively. After sacrifice, femora were dissected for micro-CT-based micro-angiography, followed by histological examination of ON lesion, intravascular thrombosis, extravascular fat-cell and vascular endothelial growth factor (VEGF) localized expression. Results The ON incidence in the L-ICT and H-ICT groups was both significantly lower than that in the CON group ( p < 0.05 for both). The ON incidence in the H-ICT group was significantly lower than that in the L-ICT group ( p < 0.05). A significant decrease in the vascularization index and a significant increase in the permeability index seen in the CON group was attenuated in the L-ICT group and almost prevented in the H-ICT group at week 1 post-induction. Reduced perfusion to vessel-like structural units was more rarely found in the H-ICT group than in the L-ICT group. Regarding intravascular thrombosis, a significant increase in the thrombotic vessel count, endothelium injury index, coagulation index, and a significant decrease in both the fibrinolysis and oxidative stress index in the CON group were attenuated in the L-ICT group and prevented in the H-ICT group. For extravascular lipid-deposition, a significant increase in the fat cell area fraction, adipogenic potential index, PPARgamma expression and lipid-transportation index in the CON group was attenuated in the L-ICT group and prevented in the H-ICT group. Increased immunoreactivity of VEGF in the CON group was attenuated in the L-ICT group and prevented in the H-ICT group. Regarding safety, the hepatocyte injury index did not show significant change from baseline in any group. Conclusion Icaritin, a novel semisynthesized small molecule with osteoprotective potential, exerts dose-dependent effect on reducing incidence of steroid-associated ON with inhibition of both intravascular thrombosis and extravascular lipid-deposition. Suppression of the up-regulated PPARgamma expression for extravascular adipogenesis of mesenchymal stem cells and protection from activated oxidative stress for intravascular endothelium injury were found to be involved in the underlying mechanisms.

An important role of continuous low marrow stem-cell-pool activity and uncontrolled VEGF-Src signaling in local abnormal vasculature during inadequate repair of steroid-associated osteonecrosis lesion

An important role of continuous low marrow stem-cell-pool activity and uncontrolled VEGF-Src signaling in local abnormal vasculature during inadequate repair of steroid-associated osteonecrosis lesion

Adipose-tissue provides a stem-cell-rich alternative source for cytotherapy of steroid-associated osteonecrosis: An in vitro study

Adipose-tissue provides a stem-cell-rich alternative source for cytotherapy of steroid-associated osteonecrosis: An in vitro study

Herbal Epimedium-derived bioactive compound icariin reduces the incidence of steroid-associated osteonecrosis

Herbal Epimedium-derived bioactive compound icariin reduces the incidence of steroid-associated osteonecrosis

Shoulder hemiarthroplasty for steroid-associated osteonecrosis

Currently, there is little information on the outcome of humeral head replacement for steroid-associated osteonecrosis of the humeral head. The purpose of this study was to evaluate the outcome of patients who underwent humeral head replacement for steroid-associated osteonecrosis to determine the results, risk factors for an unsatisfactory outcome, and rates of revision surgery. Between 1980 and 2000, 32 shoulder hemiarthroplasties were performed for steroid-associated osteonecrosis. We included 31 hemiarthroplasties in 25 patients with a minimum 2-year follow-up (mean, 12.0 years) in the study. The mean age of the 23 female and 9 male patients was 49.4 years at the time of surgery (range, 25-86 years). Overall, mean pain scores decreased from 4.6 to 2.6 (P < .0001). However, moderate or severe pain was reported in 12 shoulders (38%) at the most recent follow-up, 2 of them requiring implant revision. The mean preoperative to postoperative active elevation increased from 92 degrees to 139 degrees (P < .0001), and external rotation increased from 36 degrees to 65 degrees (P < .0001). According to a modified Neer result rating system, there were 13 excellent results (42%), 4 satisfactory results (13%), and 14 unsatisfactory results (45%). Improvement in pain and function most often occurred after hemiarthroplasty as a treatment for steroid-associated osteonecrosis of the humeral head. However, there are a large number of unsatisfactory results related to glenoid cartilage wear over time.

Elevated adipogenesis of marrow mesenchymal stem cells during early steroid-associated osteonecrosis development

BackgroundIncreased bone marrow lipid deposition in steroid-associated osteonecrosis (ON) implies that abnormalities in fat metabolism play an important role in ON development. The increase in lipid deposition might be explained by elevated adipogenesis of marrow mesenchymal stem cells (MSCs). However, it remains unclear whether there is a close association between elevated adipogenesis and steroid-associated ON development.ObjectiveThe present study was designed to test the hypothesis that there might be a close association between elevated adipogenesis and steroid-associated ON development.MethodsON rabbit model was induced based on our established protocol. Dynamic-MRI was employed for local intra-osseous perfusion evaluation in bilateral femora. Two weeks after induction, bone marrow was harvested for evaluating the ability of adipogenic differentiation of marrow MSCs at both cellular and mRNA level involving adipogenesis-related gene peroxisome proliferator-activated receptor gamma2 (PPARγ2). The bilateral femora were dissected for examining marrow lipid deposition by quantifying fat cell number, fat cell size, lipid deposition area and ON lesions. For investigating association among adipogenesis, lipid deposition and perfusion function with regard to ON occurrence, the rabbits were divided into ON+ (with at least one ON lesion) group and ON- (without ON lesion) group. For investigating association among adipogenesis, lipid deposition and perfusion function with regard to ON extension, the ON+ rabbits were further divided into sub-single-lesion group (SON group: with one ON lesion) and sub-multiple-lesion group (MON group: with more than one ON lesion).ResultsLocal intra-osseous perfusion index was found lower in either ON+ or MON group when compared to either ON- or SON group, whereas the marrow fat cells number and area were much larger in either ON+ or MON group as compared with ON- and SON group. The adipogenic differentiation ability of MSCs and PPARγ2 expression in either ON+ or MON group were elevated significantly as compared with either ON- or SON group.ConclusionThese findings support our hypothesis that there is a close association between elevated adipogenesis and steroid-associated osteonecrosis development.