Steroid-associated osteonecrosis: Epidemiology, pathophysiology, animal model, prevention, and potential treatments (an overview)

MRI spectrum of avascular necrosis of femoral head in patients treated for COVID-19

BACKGROUND AND PURPOSE

This prospective observational study aimed to investigate the occurrence of avascular necrosis (AVN) of the femoral head in COVID-19 patients through MRI scans. The study examined the patterns of AVN in 110 individuals who had undergone conventional COVID-19 therapy and reported hip discomfort. This study highlights the importance of considering AVN as a potential complication of COVID-19 therapy, particularly in younger patients who experience hip discomfort.

METHODS

Individuals who had corticosteroid treatment for COVID-19 and experienced hip discomfort during 6 months between January 2022 and August 2022 were included in this study, and an MRI scan was done to observe changes in the hip joint.

RESULTS

The results were classified using the Ficat and Arlet classification system. The analysis revealed that AVN was not present in 91.81% of cases. However, Stage I AVN was detected in 4.54% of cases, Stage II AVN in 2.72% of cases, and Stage III AVN in 1.1% of cases. No cases of Stage IV AVN were observed.

CONCLUSIONS

The study concludes that AVN occurred in 6% of individuals who underwent conventional therapy for COVID-19 and experienced hip discomfort. In these settings (post COVID-19), normal MRI results were more typical, and mild AVN (Stage I) was a frequent finding in MRI scans that were positive.

A nomogram for predicting the probability of femoral head collapse in convalescent SARS patients with glucocorticoid-induced osteonecrosis of the femoral head: an 18-year population-based retrospective cohort study

Background

This study aimed to develop a nomogram capable of predicting the probability of femoral head collapse based on an 18-year follow-up cohort of convalescent severe acute respiratory syndrome (SARS) patients with glucocorticoid-induced osteonecrosis of the femoral head (ONFH).

Methods

Data on the natural history of 120 patients (205 hips) who underwent glucocorticoid-induced ONFH at China-Japan Friendship Hospital (CJFH) in 2003 were retrospectively collected. Follow-up was conducted from June 2003 to October 2021. A nomogram was developed in a training cohort and validated in another cohort.

Results

A total of 205 hips were included for analysis, with 143 hips in the training cohorts and 62 hips in the validation cohorts. After 18 years of follow-up, 53 femoral heads collapsed, while 152 femoral heads spontaneously repaired to some extent (necrotic areas reduced or vanished). Following multivariate regression analysis, the Association Research Circulation Osseous (ARCO) staging, necrosis index (NI), and CJFH Classification were entered into the nomogram. The nomogram showed robust discrimination, with an AUC of 0.907 (95% CI: 0.85-0.96). The calibration curves showed an agreement between the probability as predicted by the nomogram and the actual probability. Application of the nomogram in the validation cohort also yielded good discrimination (AUC, 0.876, 95% CI: 0.7751-0.9761) and calibration.

Conclusion

The nomogram successfully predicted femoral head collapse in glucocorticoid-induced ONFH. With the nomogram, the prognosis for an individual patient with glucocorticoid-induced ONFH can be determined, which can lead to a rational therapeutic choice.

The protective role of vitamins C and E in steroid-induced femoral head osteonecrosis: An experimental study in rats

OBJECTIVES

This study aimed to determine whether vitamin C (VC) and vitamin E (VE) can effectively protect the femoral head and reduce the risk of developing osteonecrosis in rats that have been treated with steroids.

MATERIALS AND METHODS

The study was conducted on 30 young adult male Sprague-Dawley rats (mean weight: 356±18 g; range, 330 to 375 g), which were randomly assigned to one of five groups. The control group received saline solution, while the other groups were given lipopolysaccharide/methylprednisolone (LPS/MPS) to induce osteonecrosis. Three groups in which osteonecrosis was induced were also intraperitoneally administered either VC, VE, or both once a day for four weeks. Intracardiac blood samples were taken at the end of the fourth week for biochemical examination, and the rats were then sacrificed under general anesthesia. After sacrification, right femurs were removed for histopathological, immunohistochemical, and radiologic examinations.

RESULTS

The results showed that the mean trabecular number increased significantly in the VC+VE group. There was a substantial decrease observed in the mean trabecular separation within the LPS/MPS group compared to the control group, although trabecular separation decreased in all three vitamin groups compared to the LPS/MPS group. The surface area/bone volume was significantly increased in the VC+VE group compared to the LPS/MPS group. Histological, immunohistochemical, and radiological examinations showed that the administration of VC and VE significantly reduced oxidative stress, inflammation, and microvascular dysfunction in rats with steroid-induced femoral head osteonecrosis.

CONCLUSION

This study suggests that VC, VE, and particularly VC+VE have a protective effect on the femoral head in rats with steroid-induced femoral head osteonecrosis. These findings may lead to new treatment options for patients.

A microfluidic organ-on-a-chip: into the next decade of bone tissue engineering applied in dentistry

A comprehensive understanding of the complex physiological and pathological processes associated with alveolar bones, their responses to different therapeutics strategies, and cell interactions with biomaterial becomes necessary in precisely treating patients with severe progressive periodontitis, as a bone-related issue in dentistry. However, existing monolayer cell culture or pre-clinical models have been unable to mimic the complex physiological, pathological and regeneration processes in the bone microenvironment in response to different therapeutic strategies. In this point, 'organ-on-a-chip' (OOAC) technology, specifically 'alveolar-bone-on-a-chip', is expected to resolve the problems by better imitating infection site microenvironment and microphysiology within the oral tissues. The OOAC technology is assessed in this study toward better approaches in disease modeling and better therapeutics strategy for bone tissue engineering applied in dentistry.

Femoral head avascular necrosis in COVID-19 survivors: a systematic review

The current systematic review aimed to document published cases of femoral head avascular necrosis (FHAVN) post-COVID-19, to report the COVID-19 disease characteristics and management patients received, and to evaluate how the FHAVN were diagnosed and treated among various reports. A systematic literature review was performed per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines through a comprehensive English literature search on January 2023 through four databases (Embase, PubMed, Cochrane Library, and Scopus), including studies reporting on FHAVN post-COVID-19. Fourteen articles were included, ten (71.4%) were case reports, and four (28.6%) case series reported on 104 patients having a mean age of 42.2 ± 11.7 (14:74) years, in which 182 hip joints were affected. In 13 reports, corticosteroids were used during the COVID-19 management plan for a mean of 24.8 ± 11 (7:42) days, with a mean prednisolone equivalent dose of 1238.5 ± 492.8 (100:3520) mg. A mean of 142.1 ± 107.6 (7:459) days passed between COVID-19 diagnosis and FHAVN detection, and most of the hips were stage II (70.1%), and concomitant septic arthritis was present in eight (4.4%) hips. Most hips (147, 80.8%) were treated non-surgically, of which 143 (78.6%) hips received medical treatment, while 35 (19.2%) hips were surgically managed, 16 (8.8%) core decompression, 13 (7.1%) primary THA, five (2.7%) staged THA and three (1.6%) had first stage THA (debridement and application of antibiotic-loaded cement spacer). The outcomes were acceptable as regards hip function and pain relief. Femoral head avascular necrosis post-COVID-19 infection is a real concern, primarily attributed to corticosteroid usage, besides other factors. Early suspicion and detection are mandatory, as conservative management lines are effective during early stages with acceptable outcomes. However, surgical intervention was required for progressive collapse or patients presented in the late stage.

Stem cell therapy combined with core decompression versus core decompression alone in the treatment of avascular necrosis of the femoral head: a systematic review and meta-analysis

INTRODUCTION

Accumulated clinical trials had been focused on stem cell therapy in combination of core decompression (CD) in the treatment of avascular necrosis of the femoral head (ANFH). Nonetheless, the results were inconclusive. Here, we performed a systematic review and meta-analysis of previous randomized controlled trials (RCTs) and retrospective studies to assess whether combined stem cell augmentation with CD improved the outcomes of ANFH compared with CD alone.

METHODS

The current study included 11 RCTs and 7 retrospective studies reporting the clinical outcomes of a total of 916 patients and 1257 hips. 557 and 700 hips received CD and CD plus stem cell therapy, respectively. To compare CD with CD plus stem cell therapy, we examined the clinical evaluating scores, the occurrence of the femoral head, radiologic progression and conversion to total hip arthroplasty (THA).

RESULTS

Only 10 studies reported significantly greater improvement in hip functions while combining stem cell procedure with CD. The pooled results in subgroup analysis indicated that stem cell group had a lower collapse rate on a mid-term basis (P = 0.001), when combined with mechanical support (P < 0.00001), and with extracted stem cells (P = 0.0002). Likewise, stem cell group had a lower radiographic progression rate at 2- to 5-year follow-up [P = 0.003], when combined with structural grafting (P < 0.00001), and with extracted stem cells (P = 0.004). Stem cell therapy resulted in an overall lower THA conversion rate (P < 0.0001) except that at a follow-up longer than 5 years.

CONCLUSION

Stem cell therapy combined with core decompression was more effective in preventing collapse, radiographic progression and conversion to THA. Trial Registration The current protocol has been registered in PROSPERO with the registration number: CRD42023417248.

Romiplostim in primary immune thrombocytopenia that is persistent or chronic: phase III multicenter, randomized, placebo-controlled clinical trial in China

Background

Multiple trials have confirmed that romiplostim could increase platelet count in individuals with primary immune thrombocytopenia (ITP), but no related study has assessed Chinese patients.

Objectives

To assess the effectiveness of romiplostim as a second-line treatment of persistent or chronic ITP in Chinese adults.

Methods

This phase III multicenter, randomized, placebo-controlled, double-blind, then open-label clinical trial (NCT02868099, CTR20150395) was conducted at 28 investigational sites in China. The patients were randomly assigned (3:1) to romiplostim (starting and maximum doses of 1 and 10 μg/kg, respectively) or placebo for 9 weeks (double-blind period), followed by the open-label period (both groups administered romiplostim) to week 22. The primary endpoint was the time (in weeks) during which platelet counts were ≥50 × 109/L in the double-blind period.

Results

In this study, 202 patients (romiplostim, n = 151; placebo, n = 51) started the treatment. The median (range) numbers of weeks with platelet response after 6 weeks of treatment were 2 (0-6) and 0 (0-2) in patients administered romiplostim and placebo, respectively (P < .001). During the double-blind period, the proportions of patients with treatment-emergent adverse events were comparable between the romiplostim and placebo groups (82.8% vs 82.4%). The treatment-emergent adverse event with ≥10% difference in incidence between these 2 groups was injection site bleeding (1.3% vs 11.8%).

Conclusion

Romiplostim significantly increased the time with maintained platelet response in patients with persistent or chronic ITP in comparison with placebo. No new safety signal was observed.

Trial registration

ClinicalTrials.gov, NCT02868099. www.chinadrugtrials.org.cn/clinicaltrials.searchlist.dhtml, CTR20150395.

Scientometric analysis of highly cited papers on avascular necrosis of the femoral head from 1991 to 2022

INTRODUCTION

A highly cited paper (HCP) is considered a landmark that can influence both research and clinical practice. The characteristics of HCPs in avascular necrosis of the femoral head (AVNFH) were identified and the research status was explored in a scientometric analysis.

METHODS

The present bibliometric analysis were based on the Scopus database from 1991 to 2021. Microsoft Excel and VOSviewer were used for co-authorship, co-citation, and co-occurrence analysis. From 8496 papers, only 2.9% (244) were HCPs, with 200.8 citations registered per article.

RESULTS

Of the HCPs, 11.9% and 12.3% were externally funded and had international collaboration, respectively. These were published in 84 journals by 1625 authors from 425 organizations of 33 countries. The USA, Japan, Switzerland, and Israel were the leading countries.The lead research organizations were Sinai Hospital and John Hopkins University (USA). The most impactful organizations were University of Arkansas for Medical Science, and Good Samaritan Hospital (USA). R.A. Mont (USA) and K.H. Koo (South Korea) were the most prolific contributing authors, while R. Ganz (Switzerland) and R.S. Weinstein (USA) registered the most impactful contributions. The most prolific publishing journal was the Journal of Bone and Joint Surgery.

CONCLUSION

The HCPs contributed to the knowledge of AVNFH by examining research perspectives and identifying important subareas through keyword analysis.

LEVEL OF EVIDENCE

Not applicable.

TRIAL REGISTRATION

Not applicable.

Mechanism of vascular endothelial cell-derived exosomes modified with vascular endothelial growth factor in steroid-induced femoral head necrosis

Steroid-induced avascular necrosis of the femoral head (SANFH) is an intractable orthopedic disease. This study investigated the regulatory effect and molecular mechanism of vascular endothelial cell (VEC)-derived exosomes (Exos) modified with vascular endothelial growth factor (VEGF) in osteogenic and adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in SANFH. VECs were culturedin vitroand transfected with adenovirus Adv-VEGF plasmids. Exos were extracted and identified.In vitro/vivoSANFH models were established and treated with VEGF-modified VEC-Exos (VEGF-VEC-Exos). The internalization of Exos by BMSCs, proliferation and osteogenic and adipogenic differentiation of BMSCs were determined by the uptake test, cell counting kit-8 (CCK-8) assay, alizarin red staining, and oil red O staining. Meanwhile, the mRNA level of VEGF, the appearance of the femoral head, and histological analysis were assessed by reverse transcription quantitative polymerase chain reaction and hematoxylin-eosin staining. Moreover, the protein levels of VEGF, osteogenic markers, adipogenic markers, and mitogen-activated protein kinase (MAPK)/extracellular regulated protein kinases (ERK) pathway-related indicators were examined by Western blotting, along with evaluation of the VEGF levels in femur tissues by immunohistochemistry. Glucocorticoid (GC) induced adipogenic differentiation of BMSCs and inhibited osteogenic differentiation. VEGF-VEC-Exos accelerated the osteogenic differentiation of GC-induced BMSCs and inhibited adipogenic differentiation. VEGF-VEC-Exos activated the MAPK/ERK pathway in GC-induced BMSCs. VEGF-VEC-Exos promoted osteoblast differentiation and suppressed adipogenic differentiation of BMSCs by activating the MAPK/ERK pathway. VEGF-VEC-Exos accelerated bone formation and restrained adipogenesis in SANFH rats. VEGF-VEC-Exos carried VEGF into BMSCs and motivated the MAPK/ERK pathway, thereby promoting osteoblast differentiation of BMSCs in SANFH, inhibiting adipogenic differentiation, and alleviating SANFH.

PDGF-BB prevents destructive repair and promotes reparative osteogenesis of steroid-associated osteonecrosis of the femoral head in rabbits

Destructive repair characterized by inadequate angiogenesis and osteogenesis is the main pathological progression in steroid-associated osteonecrosis of the femoral head (SONFH). Platelet-derived growth factor-BB (PDGF-BB) is an "angiogenesis and osteogenesis coupling" factor that has been used for the treatment of bone defects in clinic. This study was designed to analyze the ability of PDGF-BB for preventing destructive repair and promoting reparative osteogenesis in SONFH. Steroid-associated osteonecrosis (SAON) was induced and triggered destructive repair of the femoral head by repeated lipopolysaccharide (LPS) and methylprednisolone (MPS) injections in rabbits. At 2, 4, and 6 weeks after induction, recombinant human PDGF-BB, neutralizing PDGF-BB antibody, or saline was intramedullary injected into the proximal femora. At week 6 after SAON induction, the proximal femora were dissected for bone architecture and histological analysis. C3H10T1/2 cells and HUVECs were used for further mechanistic investigation. After PDGF-BB treatment, type H vessels and leptin receptor-positive (LepR+) mesenchymal stem cells (MSCs) increased in the affected femoral head, and more osteoblastic osteogenesis along the bone surfaces but scattered adipocytes in bone marrow tissue than that in the SAON group. PDGF-BB treatment prevented destructive repair progression and led to 50-70 % of osteonecrotic femoral heads undergoing reparative osteogenesis. In particular, we found that PDGF-BB could mediate MSC self-renewal and maintain their osteogenic potency by activating PDGFR/Akt/GSK3β/CERB signaling in the presence of steroids. Moreover, PDGF-BB also stabled the newly formed vascular tubes by recruiting MSCs for improving intraosseous vascular integration. PDGF-BB may be a candidate for the promotion of reparative osteogenesis in SONFH.

Screening and identification of potential key biomarkers for glucocorticoid-induced osteonecrosis of the femoral head

BACKGROUND

Glucocorticoid-induced osteonecrosis of the femoral head (GIONFH) is a common disease in osteoarticular surgery, with a high disability rate, which brings great physical and mental pain and economic burden to patients. Its specific pathogenesis has not been fully demonstrated, and there is a lack of recognized effective biomarkers for earlier detection and prompt treatment. This has become an urgent clinical problem for orthopedic scholars.

MATERIALS AND METHODS

We downloaded the gene expression profile dataset GSE123568 from the Gene Expression Omnibus database, used STRING and Cytoscape to carry out module analysis and built a gene interaction network. The four core genes most related to GIONFH in this network were ultimately found out by precise analysis and animal experiment were then conducted for verification. In this verification process, thirty-six New Zealand white rabbits were randomly divided into blank control group, model group and drug group. Except for the blank control group, the animal model of GIONFH was established by lipopolysaccharide and methylprednisolone, while the drug group was given the lipid-lowering drugs for intervention as planned. The rabbits were taken for magnetic resonance imaging at different stages, and their femoral head specimens were taken for pathological examination, then the expression of target genes in the femoral head specimens of corresponding groups was detected. Validation methods included RT-PCR and pathological examination.

RESULTS

A total of 679 differential genes were selected at first, including 276 up-regulated genes and 403 down-regulated genes. Finally, four genes with the highest degree of correlation were screened. Animal experiment results showed that ASXL1 and BNIP3L were in low expression, while FCGR2A and TYROBP were highly expressed.

CONCLUSION

Through animal experiments, it was confirmed that ASXL1, BNIP3L, FCGR2A and TYROBP screened from the comparative analysis of multiple genes in the database were closely related to GIONFH, which is important for early diagnosis of Glucocorticoid-induced osteonecrosis of the femoral head.

Avascular necrosis during alectinib treatment: Case report

CASE REPORT

We present our patient who used alectinib due to anaplastic lymphoma kinase positivity and developed avascular necrosis in the femoral head.

MANAGEMENT AND OUTCOME

In our patient who had been taking alectinib for a long time due to anaplastic lymphoma kinase positivity, avascular necrosis of the femoral head was detected as a result of the examination performed due to hip pain. Due to the responsıbılıty of the disease, her treatment contınued by making profit and loss account.

DISCUSSION

Femoral head avascular necrosis can be seen with tyrosine kinase inhibitors, although it is very rare. This is the case in the literature to develop avascular necrosis due to alectinib. We think that femoral head necrosis may develop in the patient group using alectinib and care should be taken in this regard.

The Hidden Pandemic of COVID-19-Induced Organizing Pneumonia

Since the beginning of the COVID-19 pandemic, clinical, radiological, and histopathological studies have provided evidence that organizing pneumonia is a possible consequence of the SARS-CoV2 infection. This post-COVID-19 organizing pneumonia (PCOP) causes persisting dyspnea, impaired pulmonary function, and produces radiological abnormalities for at least 5 weeks after onset of symptoms. While most patients with PCOP recover within a year after acute COVID-19, 5-25% of cases need specialized treatment. However, despite substantial resources allocated worldwide to finding a solution to this problem, there are no approved treatments for PCOP. Oral corticosteroids produce a therapeutic response in a majority of such PCOP patients, but their application is limited by the anticipated high-relapse frequency and the risk of severe adverse effects. Herein, we conduct a systematic comparison of the epidemiology, pathogenesis, and clinical presentation of the organizing pneumonias caused by COVID-19 as well as other viral infections. We also use the clinical efficacy of corticosteroids in other postinfection OPs (PIOPs) to predict the therapeutic response in the treatment of PCOP. Finally, we discuss the potential application of a candidate anti-inflammatory and antifibrotic therapy for the treatment of PCOP based on the analysis of the latest clinical trials data.

Steroid-induced osteonecrosis

Osteonecrosis associated with the use of glucocorticoids is a severe, potentially debilitating complication. In broader terms, it commonly involves the femoral head with secondary hip osteoarthritis. Osteonecrosis can also be caused by trauma and other non-traumatic factors besides steroid treatment. Nonetheless, glucocorticoid use is frequently observed in clinical settings in which this represents a common therapeutic option, including general practice, rheumatology and clinical immunology, among others. The pathogenesis involves genetic components, vascular impairment, adipocyte hypertrophy, and increased intraosseous pressure, ultimately leading to marrow and bone ischemia and necrosis and the process rapidly becomes irreversible. Osteonecrosis manifests with pain and impaired motility while the diagnosis is usually made with magnetic resonance imaging allowing early detection and potentially (dependent on the patient's needs for steroids and stage) timely management with conservative options, followed by joint replacement at late stages. In this review we discuss the pathogenesis, risk factors, diagnosis, staging, and management of this complication associated with glucocorticoid treatment.

C/EBPα regulates the fate of bone marrow mesenchymal stem cells and steroid-induced avascular necrosis of the femoral head by targeting the PPARγ signalling pathway

BACKGROUND

The imbalance of osteogenic/adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) is closely related to steroid-induced avascular necrosis of the femoral head (SANFH). We aimed to investigate the epigenetic mechanism of intramedullary fat accumulation and continuous osteonecrosis after glucocorticoid (GC) withdrawal in SANFH.

METHODS

An SANFH model was established in SD rats, which received an intermittent high GC dose for the first 4 weeks followed by an additional 4 weeks without GC. We explored the synergistic effects and mechanisms of C/EBPα and PPARγ on the differentiation of BMSCs by lentivirus-mediated gene knockdown and overexpression assays. A chromatin immunoprecipitation assay was performed to identify epigenetic modification sites on PPARγ in vivo and in vitro.

RESULTS

In the SANFH model, intramedullary fat was significantly increased, and the transcription factors C/EBPα and PPARγ were upregulated simultaneously in the femoral head. In vitro, C/EBPα promoted adipogenic differentiation of BMSCs by targeting the PPARγ signalling pathway, while overexpression of C/EBPα significantly impaired osteogenic differentiation. Further studies demonstrated that histone H3K27 acetylation of PPARγ played an important role in the epigenetic mechanism underlying SANFH. C/EBPα upregulates the histone H3K27 acetylation level in the PPARγ promoter region by inhibiting HDAC1. Additionally, inhibiting the histone acetylation level of PPARγ effectively prevented adipogenic differentiation, thus slowing the progression of SANFH.

CONCLUSIONS

Our results demonstrate the molecular mechanism by which C/EBPα regulates PPARγ expression by acetylating histones and revealed the epigenetic phenomenon in SANFH for the first time.

Comparison of the outcome of different bone grafts combined with modified core decompression for the treatment of ARCO II stage femoral head necrosis

PURPOSE

Treatment of ONFH at an early stage is a challenging issue. The modified minimally invasive core decompression combined with bone graft implantation remains controversial. This study aimed to compare the early-middle outcomes of four groups with different bone grafts.

METHODS

A total of 182 patients (192 hips) with ONFH at the ARCO II stage were randomly divided into four groups. The free fibular graft group (FFG), free vascularized fibular graft group (FVFG), autologous iliac bone group (ABG), and β-tricalcium bioceramics phosphate graft (β-TCPG) group. Each group was treated with the modified minimally invasive core decompression and bone graft implantation. The operation time and blood loss were recorded by the same observer. The clinical outcome was evaluated by the Harris Hip Score and VAS score (before, 14 days after surgery, and at the last follow-up). The radiographic progression of ONFH was evaluated at least 36 months of follow-up.

RESULTS

All cases were successful without any complications after the operation. The patients were followed up for 42 to 48 (44.62 ± 1.81) months. There were statistically significant differences among the four groups in operation time (F value = 1520.67; P < 0.01) and blood loss (F value = 5366.81; P < 0.01). The Harris Hip Score in each group was improved significantly from pre-operation to last follow-up (all P < 0.01). At the last follow-up, the difference in the Harris Hip Score in each group was not statistically significant (F value = 0.54; P = 0.984). The VAS scores in each group were decreased significantly from the pre-operation to14 days after surgery (all P < 0.01). At 14 days after surgery, the difference in the VAS score in each group was not statistically significant (F value = 0.64; P = 0.59). At the last follow-up, three hips collapsed on the femoral head in the FFG group, two in the FVFG group, two in the ABG group, and three in the β-TCPG group.

CONCLUSION

The four different bone graft implantation showed satisfactory early-middle outcomes. As compared to other bone grafts, the β-TCP bioceramics graft has the advantages of shorter operation time and lesser blood loss. It may be a choice as a bone graft for the treatment of ONFH at an early stage.

Double Trouble-COVID-19 and the Widespread Use of Corticosteroids: Are We Staring at an Osteonecrosis Epidemic?

Background

A combination of immune-mediated vascular damage and routine use of systemic corticosteroid (CS) therapy in COVID-19 may significantly increase the risk and burden of osteonecrosis (ON) after COVID-19. This narrative review explores the pathogenesis, risk factors, and possible preventive and early treatment measures for ON in COVID-19.

Methods

For this narrative review, an extensive literature search was performed using the PubMed, Medline, and Science Direct databases from January 2000 to August 2021 for relevant articles on etiopathogenesis, epidemiology, clinical manifestations, and treatment of severe acute respiratory syndrome coronavirus (SARS-CoV) infection and steroid-induced ON (SION).

Results

Pathogenesis of COVID-19, utility of corticosteroids in the treatment of COVID-19, pathogenesis of SION vis-a-vis SARS-CoV infection, associated risk factors, and early diagnosis and treatment of ON following CS therapy of SARS-CoV infection were discussed.

Conclusion

Preliminary data of COVID-19 and similar trends from the SARS 2003 epidemic indicate that the "angiocentric" pathogenesis of SARS-CoV-2 and treatment with high-dose CS may increase the risk of ON in COVID-19 patients. Risk stratification based on CS intake during COVID-19 treatment can help identify subjects at moderate to high-risk for ON where early preventive and follow-up plans can be initiated.

Osteonecrosis of the Jaws in Patients with Hereditary Thrombophilia/Hypofibrinolysis-From Pathophysiology to Therapeutic Implications

Osteonecrosis of the jaws (ONJ) usually has a clear etiology. Local infection or trauma, radiotherapy and drugs that disrupt the vascular supply or bone turnover in the jaws are its major contributors. The thrombotic occlusion of the bone’s venous outflow that occurs in individuals with hereditary thrombophilia and/or hypofibrinolysis has a less known impact on jaw health and healing capability. Our research provides the most comprehensive, up-to-date and systematized information on the prevalence and significance of hereditary thrombophilia and/or hypofibrinolysis states in ONJ. We found that hereditary prothrombotic abnormalities are common in patients with ONJ refractory to conventional medical and dental treatments. Thrombophilia traits usually coexist with hypofibrinolysis traits. We also found that frequently acquired prothrombotic abnormalities coexist with hereditary ones and enhance their negative effect on the bone. Therefore, we recommend a personalized therapeutic approach that addresses, in particular, the modifiable risk factors of ONJ. Patients will have clear benefits, as they will be relieved of persistent pain and repeated dental procedures.

An intron SNP rs2069837 in IL-6 is associated with osteonecrosis of the femoral head development

Background

Genetic polymorphisms play a crucial role in the development of osteonecrosis of the femoral head (ONFH). This study mainly explored the association of IL-6 variants and ONFH susceptibility among the Chinese Han population.

Methods

Two variants (rs2069837, and rs13306435) in the IL-6 gene were identified and genotyped from 566 patients with ONFH and 566 healthy controls. The associations between IL-6 polymorphisms and ONFH susceptibility were assessed using odds ratio (OR) and 95% confidence interval (95% CI) via logistic regression. The potential function of these two variants was predicted by the HaploReg online database.

Results

The results of the overall analysis revealed that IL-6 rs2069837 was correlated with decreased risk of ONFH among the Chinese Han population (p < 0.05). In stratified analysis, rs2069837 also reduced the susceptibility to ONFH in older people (> 51 years), males, nonsmokers, and nondrinkers (p < 0.05). However, no associations between rs13306435 and ONFH susceptibility were observed (p > 0.05).

Conclusions

To sum up, we suggested that rs2069837 G>A polymorphism in the IL-6 gene was significantly associated with a decreased risk of ONFH among the Chinese Hans. These findings underscored the crucial role of IL-6 rs2069837 in the occurrence of ONFH.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-021-01142-3.

Biofunctionalized composite scaffold to potentiate osteoconduction, angiogenesis, and favorable metabolic microenvironment for osteonecrosis therapy

Osteonecrosis is a common orthopedic disease in clinic, resulting in joint collapse if no appropriate treatment is performed in time. Core decompression is a general treatment modality for early osteonecrosis. However, effective bone regeneration in the necrotic area is still a significant challenge. This study developed a biofunctionalized composite scaffold (PLGA/nHA₃₀^VEGF) for osteonecrosis therapy through potentiation of osteoconduction, angiogenesis, and a favorable metabolic microenvironment. The composite scaffold had a porosity of 87.7% and compressive strength of 8.9 MPa. PLGA/nHA₃₀^VEGF had an average pore size of 227.6 μm and a water contact angle of 56.5° with a sustained release profile of vascular endothelial growth factor (VEGF). After the implantation of PLGA/nHA₃₀^VEGF, various osteogenic and angiogenic biomarkers were upregulated by 2–9 fold compared with no treatment. Additionally, the metabolomic and lipidomic profiling studies demonstrated that PLGA/nHA₃₀^VEGF effectively regulated the multiple metabolites and more than 20 inordinate metabolic pathways in osteonecrosis. The excellent performances reveal that the biofunctionalized composite scaffold provides an advanced adjuvant therapy modality for osteonecrosis.

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A biofunctionalized organic−inorganic composite scaffold is developed for osteonecrosis therapy.

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The biofunctionalized composite scaffold potentiates osteoconduction and angiogenesis in osteonecrosis.

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The biofunctionalized composite scaffold reverses the adverse microenvironments of osteonecrosis.

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The biofunctionalized composite scaffold provides a promising clinical modality for treatment of early osteonecrosis.

A case series of uncommon causes of maxillary osteomyelitis: Understanding the pathology and recognizing the risks

Maxillary osteomyelitis is a rare event. With emergence of bisphosphonates, the incidence of jaw osteomyelitis has increased. We report five uncommon cases, with a comprehensive review of etiology and pathology. The correlation between osteonecrosis and osteomyelitis is discussed.

Corticosteroid induced avascular necrosis and COVID-19: The drug dilemma

The severe and life-threatening nature of the COVID-19 infection, the ARDS (acute respiratory distress syndrome) as well as the cytokine storm induced by the infection, commands lifesaving high doses of steroid therapy. As in all pharmacological therapies adverse effects are present. One such adverse effect which is being reported is corticosteroid induced avascular necrosis of the femoral head/ osteonecrosis of the femoral head. It must be noted that AVN principally affects the femoral head and most commonly the anterolateral aspect thereof as it is the crux of weight bearing.  Corticosteroids induce fat mobilization and this thus innately enhances the likelihood of fat emboli developing from the liver to occlude minor blood vessels in the femur, this thereby compromises the microvascular environment. Superadded to this the steroid therapy disrupts calcium metabolism and homeostasis which induces hypertrophy in the intramedullary fat cells, Gaucher cells and inflammatory cells; whilst increasing the activity of osteoclasts, thus increasing bone resorption and decreasing calcium uptake and deposition; ultimately leading to an insufficiency in the trabecular and cortical bone. This insufficiency thus equates to an increased intraosseous pressure which impedes intramedullary circulation and results in avascular necrosis.  It is evident that avascular necrosis is directly caused by high dose steroid therapy, however the case reports have very clearly indicated that the rapid onset of AVN post recovery from the COVID-19 infection cannot be solely attributed to steroid therapy and that another benefactor induced by the COVID-19 infection is at play. It is thus vital for treating physicians to take cognisance of this adverse effect post recovery and therefore should ensure that prophylactic bisphosphonate therapy is initiated timeously and congruently.

Risk factors and pathogenesis of steroid-induced osteonecrosis of femoral head - A scoping review

Steroid induced osteonecrosis of the femoral head is commonly seen in clinical practice, but yet not fully understood. It is intriguing why only some cases develop and others escape from it. We did an extensive and up to date literature review on it, with the aim to identify its incidence, associated risk factor and pathogenesis. We found that the incidence ranged from 03 to 40%, and was more with associated risk factors. Several risk factors were identified, which included higher dose and prolonged duration of steroid consumption, and underlying disease for which the steroids were given. Pathogenesis of this disease is complex and not yet fully understood. Awareness about this condition and associated risk factors should help the clinicians in identifying the cases who are prone to develop osteonecrosis with the use of steroids.

AVASCULAR NECROSIS DUE TO CORTICOSTEROID THERAPY IN COVID-19 AS A SYNDEMIC

To date, over 163 million confirmed cases of COVID-19 and over 3.3 million deaths from COVID-19 have been reported by the World Health Organization (WHO). However, there is still no specific treatment for the disease. Some empirical and supportive medications have been used thus far, including antivirals, antipyretics, antibiotics, and corticosteroids. Corticosteroids are anti-inflammatory and immunosuppressive medications that are used to treat several diseases. These agents can produce undesirable and occasionally severe systemic adverse effects. Although the occurrence and severity of most adverse effects are related to the dose and duration of the corticosteroid therapy, avascular necrosis is not directly associated with this dose and duration, and may occur without osteoporosis. Corticosteroids are not recommended for routine use in COVID-19 patients by the WHO. However, these medications have been widely used for their treatment. Avascular necrosis is a progressive and incapacitating condition. The causes of avascular necrosis are categorized into traumatic and non-traumatic. The majority of non-traumatic cases are associated with the use of corticosteroids. Early diagnosis and treatment is crucial owing to the rapidly progressive nature of the disease. Severe COVID-19 patients are at risk of avascular necrosis due to corticosteroid therapy. The hypothesis presented herein suggests that hyperbaric oxygenation in combination with adequate calcium and vitamin D supplementation and individualized exercise may be an effective, safe, and noninvasive  treatment modality, preventing from the progression of avascular necrosis.

The efficacy of core decompression for steroid-associated osteonecrosis of the femoral head in rabbits

Although core decompression (CD) is often performed in the early stage of osteonecrosis of the femoral head (ONFH), the procedure does not always prevent subsequent deterioration and the effects of CD are not fully clarified. The aim of this study is to evaluate the efficacy of CD for steroid-associated ONFH in rabbits. Twelve male and 12 female New Zealand rabbits were injected intramuscularly 20 mg/kg of methylprednisolone once and were divided into the disease control and CD groups. In the disease control group, rabbits had no treatment and were euthanized at 12 weeks postinjection. In the CD group, rabbits underwent left femoral CD at 4 weeks postinjection and were euthanized 8 weeks postoperatively. The left femurs were collected to perform morphological, biomechanical, and histological analysis. Bone mineral density and bone volume fraction in the femoral head in the CD group were significantly higher than in the disease control group. However, no difference in the mechanical strength was observed between the two groups. Histological analysis showed that alkaline phosphatase and CD31 positive cells significantly increased in the males after CD treatment. The number of empty lacunae in the surrounding trabecular bone was significantly higher in the CD group. The current study indicated that CD improved the morphological properties, but did not improve the mechanical strength in the femoral head at early-stage ONFH. These data suggest the need for additional biological, mechanical strategies, and therapeutic windows to improve the outcome of early-stage steroid-associated ONFH.

Bone Marrow Multipotent Mesenchymal Stromal Cells as Autologous Therapy for Osteonecrosis: Effects of Age and Underlying Causes

Bone marrow (BM) is a reliable source of multipotent mesenchymal stromal cells (MSCs), which have been successfully used for treating osteonecrosis. Considering the functional advantages of BM-MSCs as bone and cartilage reparatory cells and supporting angiogenesis, several donor-related factors are also essential to consider when autologous BM-MSCs are used for such regenerative therapies. Aging is one of several factors contributing to the donor-related variability and found to be associated with a reduction of BM-MSC numbers. However, even within the same age group, other factors affecting MSC quantity and function remain incompletely understood. For patients with osteonecrosis, several underlying factors have been linked to the decrease of the proliferation of BM-MSCs as well as the impairment of their differentiation, migration, angiogenesis-support and immunoregulatory functions. This review discusses the quality and quantity of BM-MSCs in relation to the etiological conditions of osteonecrosis such as sickle cell disease, Gaucher disease, alcohol, corticosteroids, Systemic Lupus Erythematosus, diabetes, chronic renal disease and chemotherapy. A clear understanding of the regenerative potential of BM-MSCs is essential to optimize the cellular therapy of osteonecrosis and other bone damage conditions.

Effect of porosity of a functionally-graded scaffold for the treatment of corticosteroid-associated osteonecrosis of the femoral head in rabbits

Background/Objective: Core decompression (CD) with scaffold and cell-based therapies is a promising strategy for providing both mechanical support and regeneration of the osteonecrotic area for early stage osteonecrosis of the femoral head (ONFH). We designed a new 3D printed porous functionally-graded scaffold (FGS) with a central channel to facilitate delivery of transplanted cells in a hydrogel to the osteonecrotic area. However, the optimal porous structural design for the FGS for the engineering of bone in ONFH has not been elucidated. The aim of this study was to fabricate and evaluate two different porous structures (30% or 60% porosity) of the FGSs in corticosteroid-associated ONFH in rabbits.

Methods

Two different FGSs with 30% or 60% porosity containing a 1-mm central channel were 3D printed using polycaprolactone and β-tricalcium phosphate. The FGS was 3-mm diameter and 32-mm length and was composed of three segments: 1-mm in length for the non-porous proximal segment, 22-mm in length for the porous (30% versus 60%) middle segment, and 9-mm in length for the 15% porous distal segment. Eighteen male New Zealand White rabbits were given a single dose of 20 ​mg/kg methylprednisolone acetate intramuscularly. Four weeks later, rabbits were divided into three groups: the CD group, the 30% porosity FGS group, and the 60% porosity FGS group. In the CD group, a 3-mm diameter drill hole was created into the left femoral head. In the FGS groups, a 30% or 60% porosity implant was inserted into the bone tunnel. Eight weeks postoperatively, femurs were harvested and microCT, mechanical, and histological analyses were performed.

Results

The actual porosity and pore size of the middle segments were 26.4% ​± ​2.3% and 699 ​± ​56 ​μm in the 30% porosity FGS, and 56.0% ​± ​4.5% and 999 ​± ​71 ​μm in the 60% porosity FGS, respectively using microCT analysis. Bone ingrowth ratio in the 30% porosity FGS group was 73.9% ​± ​15.8%, which was significantly higher than 39.5% ​± ​13.0% in the CD group on microCT (p ​< ​0.05). Bone ingrowth ratio in the 60% porosity FGS group (61.3% ​± ​30.1%) showed no significant differences compared to the other two groups. The stiffness at the bone tunnel site in the 30% porosity FGS group was 582.4 ​± ​192.3 ​N/mm³, which was significantly higher than 338.7 ​± ​164.6 ​N/mm³ in the 60% porosity FGS group during push-out testing (p ​< ​0.05). Hematoxylin and eosin staining exhibited thick and mature trabecular bone around the porous FGS in the 30% porosity FGS group, whereas thinner, more immature trabecular bone was seen around the porous FGS in the 60% porosity FGS group.

Conclusion

These findings indicate that the 30% porosity FGS may enhance bone regeneration and have superior biomechanical properties in the bone tunnel after CD in ONFH, compared to the 60% porosity FGS.

Translation potential statement

The translational potential of this article: This FGS implant holds promise for improving outcomes of CD for early stage ONFH.

Beware of Steroid-Induced Avascular Necrosis of the Femoral Head in the Treatment of COVID-19-Experience and Lessons from the SARS Epidemic

Summary

The recent outbreak of coronavirus disease 2019 (COVID-19) has become a global epidemic. Corticosteroids have been widely used in the treatment of severe acute respiratory syndrome (SARS), and the pathological findings seen in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection are very similar to those observed in severe acute respiratory syndrome-related coronavirus (SARS-CoV) infection. However, the long-term use of corticosteroids (especially at high doses) is associated with potentially serious adverse events, particularly steroid-induced avascular necrosis of the femoral head (SANFH). In today’s global outbreak, whether corticosteroid therapy should be used, the dosage and duration of treatment, and ways for the prevention, early detection, and timely intervention of SANFH are some important issues that need to be addressed. This review aims to provide a reference for health care providers in COVID-19 endemic countries and regions.

Article Focus

Hormones are a double-edged sword. This review aims to provide a reference for health care providers in coronavirus disease 2019 (COVID-19) endemic countries and regions, especially with respect to the pros and cons of corticosteroid use in the treatment of patients with COVID-19.

Key Messages

In today’s global outbreak, whether corticosteroid therapy should be used, the dosage and duration of treatment, and ways for the prevention, early detection, and timely intervention of SANFH are some important issues that need to be addressed.

Strengths and Limitations

Since SARS was mainly prevalent in China at that time, many evidences in this paper came from the reports of Chinese scholars. There is a bias in the selection of data, which may ignore the differences in environment, race, living habits, medical level and so on. SANFH may be the result of multiple factors. Whether the virus itself is an independent risk factor for SANFH has not been confirmed. In this paper, through literature retrieval, some reference opinions on glucocorticoid usage, diagnosis and treatment of SANFH are given. However, due to the lack of large-scale research data support, it can not be used as the gold standard for the above problems.

Novel function of adrenocorticotropic hormone in the stimulation of vascular endothelial growth factor release in healthy children and adolescents: a proof-of-concept study

PURPOSE

To assess the effect of adrenocorticotropic hormone (ACTH) on plasma vascular endothelial growth factor (VEGF) levels in healthy children and adolescents and to inform future work on the effects of ACTH on VEGF in bone.

METHODS

An Institutional Review Board-approved prospective study of 10 healthy subjects, ages 9-17, was conducted to assess the effect of ACTH on plasma VEGF levels. VEGF levels were collected at baseline and every 30 minutes for 3 hours. Cosyntropin (a synthetic ACTH analogue) was administered at a low-dose (1 μg) given at t=0 minutes and a high-dose (250 μg) given at t=60 minutes. A Friedman test was performed comparing baseline to peak VEGF levels after stimulation with low-dose and high-dose cosyntropin.

RESULTS

Peak plasma VEGF levels significantly increased after high-dose cosyntropin compared with baseline (P=0.042). Peak plasma VEGF levels did not significantly increase after low-dose cosyntropin compared to baseline.

CONCLUSION

To our knowledge, this is the first study to demonstrate that ACTH administration causes a significant increase in plasma VEGF levels in humans. This finding may have important implications in the protective effects of ACTH on bone. Decreased bone mineral density and adrenal suppression are common side effects of glucocorticoid use in pediatrics. VEGF increases vascularity and may play a role in reducing glucocorticoid-induced bone disease. Animal studies have shown that ACTH stimulates release of VEGF in osteoblasts, though this effect has yet to be evaluated in humans.

Retrospective Study on Implantation of Autologous-Cultured Osteoblasts for the Treatment of Patients with Avascular Necrosis of the Femoral Head

Purpose

Osteonecrosis of the femoral head is a progressive and debilitating disease that causes pain, osteoarthritis and hip joint collapse, eventually necessitating hip replacement. This study evaluated the long-term outcomes of autologous adult live-cultured osteoblasts (AALCO) implantation in patients with osteonecrosis of femoral head.

Patients and Methods

In this retrospective multicenter study, we collated and analyzed data of patients ≥12 years of age who underwent AALCO (OSSGROW^®) between 2010 and 2015 for the treatment of osteonecrosis of the femoral head.

Results

Data from 64 patients (101 hip joints) were assessed in this study. The mean ±SD duration of disease since diagnosis of osteonecrosis was 7.4±1.6 years. The mean follow-up duration was 6.3±1.4 years. The mean VAS score (n=98 hips) reduced significantly from 58.8 ± 13.8 to 32.2 ± 32.1 post-operatively (mean difference: −26.5±35.2, p=0.001) and Harris hip score (n=97 hips) also significantly improved from 47.1±12.3 to 63.7±27.7 post-operatively (mean difference:16.7±28.7, p=0.0001). Following the AALCO treatment, 29 hips in 13 patients (28.7%) underwent total hip replacement (THA), indicating that AALCO treatment could delay THA for 71.3% of hips. A total of 39.1% of hips diagnosed in early stage versus 60.8% in the late stage of osteonecrosis required THA. Overall, 60.4% of hips improved, 2% remained stable, and 37.6% progressed following the AALCO implantation. The condition of disease was found to have improved in 71.1% of patients in early stage (Grades I and II) versus 58% in the late stage (Grades III and IV) of osteonecrosis.

Conclusion

Patients with osteonecrosis who received implantation of autologous-cultured osteoblasts using AALCO showed improvement in joint function and decrease in pain. Treatment with AALCO halted progression of osteonecrosis, preserved the natural hip, and eliminated the need for hip replacement surgeries in 7 out of 10 patients.

Sox11 Modified Tendon-Derived Stem Cells Promote the Repair of Osteonecrosis of Femoral Head

Osteonecrosis of the femoral head (ONFH) is a leading cause of mobility impairment which may lead to a total hip replacement. Recent studies have found tendon derived stem cells (TDSCs) might be an ideal cell source for musculoskeletal tissue regeneration. And our previous study has shown Sox11 could promote osteogenesis of bone marrow-derived MSCs. However, the effect of TDSCs or Sox11 over-expressing TDSCs (TDSCs-Sox11) on bone regeneration in ONFH has not been investigated. In the present study, TDSCs were infected with AAV carrying Sox11 or empty vector. We showed that Sox11 could promote the proliferation and osteogenic differentiation of TDSCs, as well as angiogenesis in vitro. The western blot analysis showed that Sox11 could activate the PI3K/Akt signaling pathway to promote osteogenesis of TDSCs. Finally, using a rabbit model of hormone-induced ONFH, our result demonstrated that local administration of TDSCs or TDSCs overexpressing Sox11 could accelerate bone regeneration in necrotic femoral heads, and TDSCs overexpressing Sox11 showed better effects. TDSCs over-expressing Sox11 might be a promising cell source for stem cell therapy to promote bone regeneration, such as ONFH, fracture, bone defect, and so on.

Glucocorticoids induce femoral head necrosis in rats through the ROS/JNK/c-Jun pathway

Osteonecrosis of the femoral head (ONFH) is a common clinical disease with a high disability rate. Apoptosis of osteoblasts caused by high‐dose short‐term or low‐dose long‐term glucocorticoid (GC) administration is the biological basis of steroid‐induced avascular necrosis of the femoral head (SANFH). The pathogenesis of SANFH has not yet been fully elucidated, and there is currently a lack of effective clinical treatments. Here, we investigated the role of the reactive oxygen species (ROS)/JNK/c‐Jun signaling pathway in SANFH. Dexamethasone (Dex) was used to induce apoptosis in osteoblasts, and this resulted in a significant increase in levels of p‐JNK, p‐c‐Jun, Bax, caspase‐3, caspase‐9, cytochrome C, Beclin‐1, and LC3, and a decrease in levels of P62 and Bcl‐2. In addition, intracellular ROS levels were increased and mitochondrial membrane potential was decreased. Administration of 3‐MA, an autophagy inhibitor, attenuated Dex‐mediated changes in autophagy and apoptosis. A rat model of ONFH exhibited severe bone trabecular hollow bone pits along with a significant increase in femoral head cell apoptosis compared with the control group. Additionally, micro‐CT analysis showed that both bone tissue content and femoral head integrity were significantly reduced in the ONFH group. Furthermore, 3‐MA treatment decreased the effect of Dex on GC‐induced ONFH and osteoblast apoptosis in rats and could counteract microstructure destruction due to femoral head necrosis. In summary, our data suggest that GC can induce osteoblast apoptosis and autophagy through the ROS/JNK/c‐Jun signaling pathway, which contributes to ONFH.

Apolipoprotein D alleviates glucocorticoid-induced osteogenesis suppression in bone marrow mesenchymal stem cells via the PI3K/Akt pathway

Background

To clarify the role of apolipoprotein D (Apod) in alleviating glucocorticoid-induced osteogenesis suppression in bone marrow mesenchymal stem cells (MSCs) via the PI3K/Akt pathway, thus influencing the progression of osteoporosis (OP).

Methods

Osteogenesis in MSCs was induced by dexamethasone (DEX) stimulation. Dynamic expressions of Apod in MSCs undergoing osteogenesis for different time points were determined by qRT-PCR. Relative levels of osteogenesis-associated genes, including ALP, RUNX2, and Osterix, in DEX-induced MSCs overexpressing Apod or not were examined. Moreover, the protein level of RUNX2, ALP, and Osterix; ALP activity; and mineralization ability influenced by Apod in osteogenic MSCs were assessed. At last, the potential influences of Apod on the PI3K/Akt pathway were identified through detecting the expression levels of PI3K and Akt in MSCs by Western blot.

Results

Apod was time-dependently upregulated in MSCs undergoing osteogenesis. DEX induction downregulated ALP, RUNX2, and Osterix and attenuated ALP activity and mineralization ability in MSCs undergoing osteogenesis, which were partially reversed by overexpression of Apod. In addition, Apod overexpression upregulated the reduced levels of PI3K and Akt in DEX-induced MSCs.

Conclusion

Apod alleviates glucocorticoid-induced osteogenesis suppression in MSCs via the PI3K/Akt pathway, thus protecting the progression of OP.

Assessment of proliferation, migration and differentiation potentials of bone marrow mesenchymal stem cells labeling with silica-coated and amine-modified superparamagnetic iron oxide nanoparticles

Superparamagnetic iron oxide nanoparticles have been widely used for cell labeling in preclinical and clinical studies, to improve labeling efficiency, particle conjugation and surface modifications are developed, but some modified SPIONs exert side-effect on physiological activity of cells, which cannot be served as ideal cell tracker. In this study, amine-modified silica-coated SPIO (SPIO@SiO₂-NH₂, SPIO@S-N) nanoparticles were used to label bone marrow derived mesenchymal stem cells (BM-MSCs), then the stem cell potentials were evaluated. It was found BM-MSCs could be efficiently labeled by SPIO@S-N nanoparticles. After labeling, the BM-MSCs viability kept well and the migration ability increased, but the osteogenesis and adipogenesis potentials were not impaired. In steroid associated osteonecrosis (SAON) bone defect model, stem cell implantation was performed by injection of SPIO@S-N labeled BM-MSCs into marrow cavity locally, it was found the SPIO positive cells homed to the periphery of defect region in control group, but were recruited to the defect region in poly lactic-coglycolic acid/tricalcium phosphate (PLGA/TCP) scaffold implantation group. In conclusion, SPIO@S-N nanoparticles promoted migration while retained proliferation and differentiation ability of BM-MSCs, implying this kind of nanoparticles could be served not only an ideal tracking marker but also an accelerator for stem cell homing during tissue repair.

Anti-inflammatory effects of Jingshu Keli capsule and its components on human synoviocyte MH7A cells

BACKGROUND

Jingshu Keli (JSKL), a traditional Chinese medicine (TCM) formula consisting of multiple active compounds, has been officially approved by National Medical Products Administration (NMPA) for treatment of cervical radiculopathy. It relieves pain, according to TCM theory, by activating blood circulation to dissipate blood stasis. The pain mainly stems from neurogenic inflammation caused by mechanical compression of the cervical nerve root. In addition, inflammation mediators also cause the development of other joint diseases, such as osteoarthritis (OA). The purpose of this paper was to evaluate the anti-inflammatory effects of JSKL and identify the biologically active herbs and compounds in vitro.

METHODS

Enzyme-linked immunosorbent assay (Elisa) was used to determine the expression of pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6) and interleukin 8 (IL-8), in the culture medium of human MH7A cells stimulated by lipopolysaccharides (LPS).

RESULTS

JSKL and three single-herb capsules, Cinnamomum cassia Presl (C.C.), Angelica Sinensis (Oliv.) Diels (A.S.) and Carthamus tinctorius L. (C.T.), significantly inhibited the secretion of TNF-α. If one of these three herbal components was removed, suppressing effect of the single-herb-deleted JSKL on TNF-α was abolished. Cinnamaldehyde (CIN) from C.C. was the most potent ingredient that inhibited the expression of IL-6 and IL-8 in the culture medium of both LPS-stimulated MH7A cells and primary synovial cells.

CONCLUSIONS

JSKL was found to possess anti-inflammatory effect in vitro; C.C., A.S. and C.T. were the principal and essential herbal components responsible for such activity; CIN from C.C. is one the most potent single compound among indicator components of JSKL recorded in 2015 Chinese pharmacopoeia. This study provided scientific evidence for the clinical application of JSKL as an agent for targeted treatment of cervical radiculopathy. Furthermore, CIN has potential to be used for the treatment of some inflammation-related orthopedic diseases, such as rheumatic arthritis and osteoarthritis.

Guidelines for clinical diagnosis and treatment of osteonecrosis of the femoral head in adults (2019 version)

Osteonecrosis of the femoral head (ONFH) is a common and refractory disease in orthopaedic clinics. The number of patients with ONFH is increasing worldwide every year. There are an estimated 8.12 million patients with nontraumatic osteonecrosis in China alone. Treatment of nontraumatic osteonecrosis has always been a clinical challenge for orthopaedic surgeons. To further standardize diagnosis and treatment of ONFH, these guidelines provide not only basic diagnosis, treatment, and evaluation systems for ONFH but also expert advice and standards in many aspects, including epidemiology, aetiology, diagnostic criteria, pathological staging, prevention and treatment options, and postoperative rehabilitation. The aetiological factors of ONFH can currently be divided into two major categories: traumatic and nontraumatic; however, the specific pathological mechanism of ONFH is not completely clear. Currently, the staging system of ONFH formulated by the Association Research Circulation Osseous is widely used in clinical practice. Based on the changes in the intraosseous blood supply at different stages, the corresponding nonsurgical and surgical treatments are recommended, and when there are risk factors for possible ONFH, certain preventive measures to avoid the occurrence of osteonecrosis are recommended. These guidelines provide brief classification criteria and treatment regimen for osteonecrosis. Specification of the aetiology, treatment plan based on comprehensive consideration of the different stages of osteonecrosis, hip function, age, and occupation of the patients are important steps in diagnosis and developing treatment strategies.

TRANSLATIONAL POTENTIAL OF THIS ARTICLE

New advances in the epidemiology, etiology, pathophysiology, imaging, diagnosis and treatment of ONFH have been renewed in this revision. This guideline can be used for reference by orthopedic professionals and researchers, and for standardized diagnosis and treatment management under the clinical guidance, which is conducive to the prevention, treatment and further research of ONFH, improving the diagnosis and treatment level, making patients' symptoms under good control, and improving their quality of life.

[Effect of icariin on early steroid-induced osteonecrosis of the femoral head in rabbits]

Objective

To explore the effect of icariin on early steroid-induced osteonecrosis of the femoral head in rabbits.

Methods

Fifty mature New Zealand rabbits (weighing, 2.5-3.0 kg) were randomly divided into control group ( n=10), model group ( n=20), and experimental group ( n=20). The rabbits of model and experimental groups were injected with lipopolysaccharide and methylprednisolone to establish the animal model of early steroid-induced osteonecrosis of the femoral head. The rabbits of experimental group were feeded with icariin solution once a day for 6 weeks since the first injection of methylprednisolone, whereas the rabbits of control and model groups were given normal saline at the same time points. The left femoral heads were removed after 6 weeks and gross morphological features were evaluated. Micro-CT scan was performed to analyze the trabecular microstructure with the following parameters: trabecular bone volume to total volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Tn), and trabecular separation (Tb.Sp). The Micro-CT scan was also converted to three-dimensional reconstruction images for observation. HE staining was applied to observe the trabecular structure and morphological changes of osteocytes and marrow adipocytes. It was also used to determine whether the samples of femoral heads occurred osteonecrosis based on the criteria for pathological diagnosis, and calculate the rate of empty lacunae.

Results

Seven rabbits died during the study, and 9, 16, and 18 rabbits in the control, model, and experimental groups, respectively, enrolled the final analysis. Compared with control group, the femoral head collapse and trabecular breaks were more obvious, and the trabeculae were sparse with irregular arrangement in the model group according to the results of gross observation, Micro-CT scan, and three-dimensional reconstruction images. But in the experimental group, the surface of femoral head was slight shrinking without obvious collapse, and the degeneration of trabecular structure was mild. According to bone microstructures analysis, the Tb.N, Tb.Tn, and BV/TV of femoral head in model and experimental groups were lower than those in control group, while the Tb.Sp in the model and experimental groups were significantly higher. The Tb.N, Tb.Tn, and BV/TV of femoral head in experimental group were higher than those in model group, while the Tb.Sp in the experimental group was significantly lower. The differences between groups were all significant ( P<0.05). In the model group, HE staining showed that the number of osteocytes reduced, the number of empty lacunae increased, and the marrow adipocytes piled up in the space between femoral trabeculae, some even mashed together like a cyst. In the experimental group, the trabecular structure was still relatively complete compared with model group, no obvious apoptosis of osteocytes was observed, the size and number of adipocytes were basically normal. None of the animals in control group occurred osteonecrosis of the femoral head based on the criteria for pathological diagnosis, and the incidence of osteonecrosis were 81.3% (13/16) in the model group and 66.7% (12/18) in the experimental group, and the difference was not significant ( P=0.448). The rate of empty lacunae of osteonecrotic femoral heads in the model group was 33.1%±1.4%, which was higher than that in experimental group (18.9%±0.8%) and in control group (12.7%±1.5%), and the differences between groups were significant ( P<0.05).

Conclusion

The icariin has a protective effect on the early steroid-induced osteonecrosis of the femoral head in rabbits, which can decrease osteocytes apoptosis, improve the bone microstructure, and delay such disease processes.

Osteonecrosis of the Hip: A Primer

In this report, we deliver a concise and up-to-date review of osteonecrosis, a pathologic, painful, and often disabling condition that is believed to result from the temporary or permanent disruption of blood supply to an affected area of bone. We will discuss the epidemiology (disease distribution), pathogenesis (mechanism of development), etiology (associated risk factors, causes, and disorders), clinical manifestations (reported symptoms and physical findings), diagnosis and classification, and treatment options for hip osteonecrosis.

Current surgical options and innovation for repairing articular cartilage defects in the femoral head

Total hip arthroplasty is a common surgical technique, yet it has severe complications, such as loosening and repeated revision. Thus, hip-preserving surgical options should be considered first to treat cartilage defects in the femoral head, especially for younger patients. Current surgical options for chondral repair of the femoral head include microfracture, trapdoor procedure, transplantation of osteochondral allografts and autografts, and autologous chondrocyte implantation. Each of these techniques has unique advantages and limitations; however, none of them have been consented as the best practice for cartilage defects. In this review article, we also introduced a novel technique for repairing osteochondral defects of the femoral head using autologous costal cartilage grafts that may have good translational potential for cost-effective and safe applications.

The translational potential of this article

This review updates current surgical options for reparing articular cartilage defects in the femoral head. We also introduce a novel technique for repairing osteochondral defects of the femoral head using autologous costal cartilage grafts.

Bloodstream infections exacerbate incidence and severity of symptomatic glucocorticoid-induced osteonecrosis

BACKGROUND

Osteonecrosis is a common toxicity associated with glucocorticoid (e.g., dexamethasone and prednisone) treatment of children with acute lymphoblastic leukemia (ALL), but risk factors are incompletely defined. Infections are also a common complication of ALL therapy. Lipopolysaccharide (LPS) is used experimentally to mimic infection-related systemic effects. To our knowledge, the contribution of systemic infections to the risk of glucocorticoid-induced osteonecrosis has not been investigated.

PROCEDURE

Patients with ALL on St. Jude Total Therapy XV (n = 365) were assessed for documented bacteremia prior to development of osteonecrosis, which was confirmed by MRI, and graded using the National Cancer Institute's Common Terminology for Adverse Events (version 3.0). In a preclinical model, Balb/cJ mice treated with dexamethasone plus or minus LPS were assessed for frequency and severity of osteonecrosis and arteriopathy.

RESULTS

We found that patients with ALL who experienced bacteremia had a higher frequency of symptomatic osteonecrosis (≥grade 2) than those who did not (OR: 1.88; 95% CI, 1.03-3.41, P = 0.038). LPS exacerbated experimental dexamethasone-induced osteonecrosis. Mice treated with dexamethasone plus LPS had a higher incidence of osteonecrosis (P = 0.00086) and arteriopathy (P = 0.0047) than did those treated with dexamethasone alone, and the severity of osteonecrosis (P = 0.00045) and arteriopathy (P = 0.0048) was also more pronounced with the addition of LPS treatment. The increase in osteonecrosis was not explained by any alteration of dexamethasone pharmacokinetics by LPS.

CONCLUSIONS

These data identify systemic infection during ALL therapy as a novel risk factor in the development of glucocorticoid-induced osteonecrosis.

Dose-related histopathology and bone remodeling characteristics of the knee articular cartilage and subchondral bone induced by glucocorticoids in rats

The aim of the current study was to investigate histopathological changes and bone remodeling in the knee articular cartilage and subchondral bone in rats following treatment with glucocorticoids. A total of 30 3-month-old female Sprague-Dawley rats were randomly divided into either a vehicle control group or one of three experimental groups wherein dexamethasone (Dex) was administered at a dose of 1.0, 2.5 or 5.0 mg/kg (Dex1.0, Dex2.5 and Dex5.0, respectively), for 8 weeks. Articular cartilage and the epiphyseal subchondral bone of the proximal tibias were evaluated by histopathology or for bone remodeling using histomorphometry. No histological changes were identified in the knee articular cartilage but the bone formation rate of the subchondral bone was lower in the Dex1.0 group compared with that of the control group. Compared with the control and the Dex1.0 group, the width of the articular cartilage and the subchondral plate were larger, with abnormal morphology and increased apoptosis of chondrocytes, decreased cell/matrix volume ratio in the cartilage and fewer blood vessels in the subchondral plate in the Dex2.5 and Dex5.0 groups. A higher Dex dose resulted in more severe inhibition of bone formation, a greater number of apoptotic osteocytes and constrained bone resorption. All microstructure parameters indicated no significant changes in the Dex2.5 group but exhibited deterioration in the Dex5.0 group compared with the normal and Dex1.0 group. There were no significant differences in morphological changes, or in static and dynamic bone indices between the Dex2.5 and Dex5.0 groups. In conclusion, long-term glucocorticoid use induced dose-related histopathological changes in the knee articular cartilage, along with unbalanced bone remodeling and osteopenia in the subchondral bone. The degree of damage to the articular cartilage was milder and transformed from compensation to degeneration at higher doses.

Dynamic and Cell-Infiltratable Hydrogels as Injectable Carrier of Therapeutic Cells and Drugs for Treating Challenging Bone Defects

Biopolymeric hydrogels have been widely used as carriers of therapeutic cells and drugs for biomedical applications. However, most conventional hydrogels cannot be injected after gelation and do not support the infiltration of cells because of the static nature of their network structure. Here, we develop unique cell-infiltratable and injectable (Ci-I) gelatin hydrogels, which are physically cross-linked by weak and highly dynamic host-guest complexations and are further reinforced by limited chemical cross-linking for enhanced stability, and then demonstrate the outstanding properties of these Ci-I gelatin hydrogels. The highly dynamic network of Ci-I hydrogels allows injection of prefabricated hydrogels with encapsulated cells and drugs, thereby simplifying administration during surgery. Furthermore, the reversible nature of the weak host-guest cross-links enables infiltration and migration of external cells into Ci-I gelatin hydrogels, thereby promoting the participation of endogenous cells in the healing process. Our findings show that Ci-I hydrogels can mediate sustained delivery of small hydrophobic molecular drugs (e.g., icaritin) to boost differentiation of stem cells while avoiding the adverse effects (e.g., in treatment of bone necrosis) associated with high drug dosage. The injection of Ci-I hydrogels encapsulating mesenchymal stem cells (MSCs) and drug (icaritin) efficiently prevented the decrease in bone mineral density (BMD) and promoted in situ bone regeneration in an animal model of steroid-associated osteonecrosis (SAON) of the hip by creating the microenvironment favoring the osteogenic differentiation of MSCs, including the recruited endogenous cells. We believe that this is the first demonstration on applying injectable hydrogels as effective carriers of therapeutic cargo for treating dysfunctions in deep and enclosed anatomical sites via a minimally invasive procedure.

The effects of a functionally-graded scaffold and bone marrow-derived mononuclear cells on steroid-induced femoral head osteonecrosis

Osteonecrosis of the femoral head (ONFH) is a debilitating disease that may progress to femoral head collapse and subsequently, degenerative arthritis. Although injection of bone marrow-derived mononuclear cells (BMMCs) is often performed with core decompression (CD) in the early stage of ONFH, these treatments are not always effective in prevention of disease progression and femoral head collapse. We previously described a novel 3D printed, customized functionally-graded scaffold (FGS) that improved bone growth in the femoral head after CD in a normal healthy rabbit, by providing structural and mechanical guidance. The present study demonstrates similar results of the FGS in a rabbit steroid-induced osteonecrosis model. Furthermore, the injection of BMMCs into the CD decreased the osteonecrotic area in the femoral head. Thus, the combination of FGS and BMMC provides a new therapy modality that may improve the outcome of CD for early stage of ONFH by providing both enhanced biological and biomechanical cues to promote bone regeneration in the osteonecrotic area.

Strain-specific differences in the development of bone loss and incidence of osteonecrosis following glucocorticoid treatment in two different mouse strains

Objective

Glucocorticoids (GCs) are commonly prescribed as treatment for chronic inflammatory diseases. Prolonged use of GCs is a common cause of atraumatic osteonecrosis (ON) and secondary osteoporosis. Currently, there is no effective treatment for this disease; therefore, a reliable animal model would be useful to study both the pathology and novel treatment strategies for patients with the disease. The aim of this study was to establish a validated, reproducible model of GC-induced ON and bone loss in two different mouse strains (BALB/c and C57BL/6).

Methods

Seven-week-old male BALB/c (n = 32) and male C57BL/6 mice (n = 32) were randomised into placebo or GC groups and treated with daily 4 mg/L oral dexamethasone in drinking water for 90 days. Study outcome measures included histologic assessment of ON of the distal femur, bone mass and mechanical strength of tibia and lumbar vertebral body, osteoclast number, biochemical measure of bone formation and bone marrow fat quantitation.

Results

GC-induced ON lesions were observed in the distal femur in 47% of the male BALB/c mice and 25% of the male C57BL/6 mice. GC treatment decreased the trabecular bone volume and serum pro-collagen type 1N-protease (P1NP) in BALB/c mice compared with the placebo (p < 0.05) and reduced tibial bone strength in both BALB/c and C57BL/6 mice. GC-treated BALB/c mice had significantly greater marrow fat levels compared to the placebo group.

Conclusion

GC-induced ON was more prevalent in the male BALB/c mice compared to the male C57BL/6 mice. GC treatment significantly reduced bone mass, bone formation measured by P1NP, bone strength and increased marrow fat levels in male BALB/c mice. Therefore, the use of male BALB/c mice strain is recommended for both diagnostic and therapeutic studies for the prevention and treatment of ON and bone loss following prolonged treatment with GCs.

The Translational Potential of this Article

GCs are commonly used to treat patients with various chronic inflammatory diseases, and this is associated with both the development of ON and bone loss. Our study confirmed that the BALB/c mouse strain treated for 90 days with GC may be useful for developing novel treatments for ON.

Efficiency of Cell Therapy to GC-Induced ONFH: BMSCs with Dkk-1 Interference Is Not Superior to Unmodified BMSCs

Glucocorticoid-induced osteonecrosis of the femoral head (ONFH) is a hip disorder, and it threatens patients who require megadose of steroid therapies. Nowadays, no valid therapies can reverse the development of GC-induced ONFH once it occurs. Stem cell therapy to GC-induced ONFH would be a promising choice. Although the pathogenesis of GC-induced ONFH is not yet fully clear, Dickkopf-1 (Dkk-1) upregulated by excessive GC use, which hinders the canonical Wnt pathway, could be an explanation. Thus, the aim of the present work lies in investigating the efficiency of the allograft bone marrow stem cells (BMSCs) with Dkk-1 interference in preventing the progression of the GC-induced ONFH. Lentivirus-meditated Dkk-1 RNAi was introduced into BMSCs which was exposed to dexamethasone (10-6 mol/L) in vitro. This interference blocked Dkk-1 overexpression by GC and afterwards prompted the transduction of Wnt/β-catenin in which the Runx2 and PPARγ were upregulated and downregulated, respectively. Thus, the osteogenesis was promoted while adipogenesis was inhibited. In vivo, GC-induced ONFH rats were treated by allotransplantation of BMSCs with Dkk-1 interference, and the progression of the disease was prevented. However, the effects were not significantly superior to treatment with nongenetically modified or normal BMSCs.

Quantitative determination of residual 1,4-dioxane in three-dimensional printed bone scaffold

Background/Objective

A novel porous scaffold poly (lactide-co-glycolide) and tricalcium phosphate (PLGA/TCP) was developed by three-dimensional printing technology for bone defect repair. As a Class 2 solvent with less severe toxicity, content of residual 1,4-dioxane in this newly developed scaffold should be rigorously controlled when it is translated to clinical use. In this study, a headspace gas chromatography-mass spectrometric (HS-GC-MS) method and related testing protocol were developed for quantitative determination of 1,4-dioxane in the PLGA/TCP composite scaffolds.

Methods

Matrix effect analysis was used to optimise the pretreatment method of the scaffolds. Then, the procedure for testing 1,4-dioxane using HS-GC-MS was set up. The accuracy, precision, and robustness of this newly developed quantitative method were also validated before quantification of 1,4-dioxane in the scaffolds with different drying procedures.

Results

Dimethyl formamide (DMF) was the optimal solvent for dissolving scaffolds for GC-MS with proper sensitivity and without matrix effect. Then, the optimised procedure was determined as: the scaffolds were dissolved in DMF and kept at 90°C for 40 minutes, separated on a HP-5MS column, and detected by mass spectroscopy. Recovery experiments gave 97.9–100.7% recovery for 1,4-dioxane. The linear range for 1,4-dioxane was determined as 1–40 ppm with linear correlation coefficient ≥ 0.9999. Intraday and interday precision was determined as being within relative standard deviation of below 0.68%. The passable drying procedure was related to lyophilising (−50°C, 50 Pa) the scaffolds for 2 days and drying in vacuum (50 Pa) for 7 days.

Conclusion

This is the first quantitative method established to test 1,4-dixoane in a novel scaffold. This method was validated with good accuracy and reproducibility, and met the methodological requirements of the Guideline 9101 documented in the Chinese Pharmacopoeia 2015 Edition.

The translational potential of this article

This quantitative method for determination of residual 1,4-dioxane in the novel scaffolds is a key technical method during its translation into clinical use because this method is an important and indispensable file in the enterprise standard when the porous scaffold is registered as a Class III implanted medical device for bone defect repair, which is used to guarantee the safety of the scaffolds. It is also applied to optimise the drying process of scaffolds and to monitor the quality of scaffolds in the industrialisation process. Further, this method provides references for other solvents quantitative determination in porous scaffolds or materials.

Steroid-associated osteonecrosis animal model in rats

OBJECTIVE

Established preclinical disease models are essential for not only studying aetiology and/or pathophysiology of the relevant diseases but more importantly also for testing prevention and/or treatment concept(s). The present study proposed and established a detailed induction and assessment protocol for a unique and cost-effective preclinical steroid-associated osteonecrosis (SAON) in rats with pulsed injections of lipopolysaccharide (LPS) and methylprednisolone (MPS).

METHODS

Sixteen 24-week-old male Sprague-Dawley rats were used to induce SAON by one intravenous injection of LPS (0.2 mg/kg) and three intraperitoneal injections of MPS (100 mg/kg) with a time interval of 24 hour, and then, MPS (40 mg/kg) was intraperitoneally injected three times a week from week 2 until sacrifice. Additional 12 rats were used as normal controls. Two and six weeks after induction, animals were scanned by metabolic dual energy X-ray absorptiometry for evaluation of tissue composition; serum was collected for bone turnover markers, Microfil perfusion was performed for angiography, the liver was collected for histopathology and bilateral femora and bilateral tibiae were collected for histological examination.

RESULTS

Three rats died after LPS injection, i.e., with 15.8% (3/19) mortality. Histological evaluation showed 100% incidence of SAON at week 2. Dual energy X-ray absorptiometry showed significantly higher fat percent and lower lean mass in SAON group at week 6. Micro-computed tomography (Micro-CT) showed significant bone degradation at proximal tibia 6 weeks after SAON induction. Angiography illustrated significantly less blood vessels in the proximal tibia and significantly more leakage particles in the distal tibia 2 weeks after SAON induction. Serum amino-terminal propeptide of type I collagen and osteocalcin were significantly lower at both 2 and 6 weeks after SAON induction, and serum carboxy-terminal telopeptide was significantly lower at 6 weeks after SAON induction. Histomorphometry revealed significantly lower osteoblast surface and higher marrow fat fraction and oedema area in SAON group. Hepatic oedema appeared 2 weeks after SAON induction, and lipid accumulation appeared in the liver of SAON rats 6 weeks after SAON induction.

CONCLUSION

The present study successfully induced SAON in rats with pulsed injection of LPS and MPS, which was well simulating the clinical feature and pathology. Apart from available large animal models, such as bipedal emus or quadrupedal rabbits, our current SAON small model in rats could be a cost-effective preclinical experimental model to study body metabolism, molecular mechanism of SAON and potential drugs developed for prevention or treatment of SAON.

THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE

The present study successfully induced SAON in a small animal model in rats with pulsed injection of LPS and MPS. The evaluation protocols with typical histopathologic ON features and advanced evaluation approaches to identify the metabolic disorders of SAON could be used in future rat SAON studies. The SAON rat model is a suitable and cost-effective animal model to study molecular mechanism of SAON and potential drugs developed for prevention and treatment of SAON.

A Traditional Herbal Formula Xianlinggubao for Pain Control and Function Improvement in Patients with Knee and Hand Osteoarthritis: A Multicenter, Randomized, Open-Label, Controlled Trial

Evidence of efficacy of a traditional herbal formula Xianlinggubao (XLGB) for treatment of osteoarthritis (OA) is limited. The present study was designed to evaluate the efficacy of XLGB in the management of patients with knee and hand OA. This was a multicenter, stratified, open-label, randomized controlled trial conducted at six centers in China. People aged 40 or above, diagnosed with OA of the knee or hand, were randomly assigned to the XLGB treatment group or watchful waiting control group. Main outcome measures were the changes in the numeric pain rating scales (NPRS) and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) or the Australian/Canadian Osteoarthritis Hand Index (AUSCAN) scores, from baseline to 6 months. In total 534 patients (272 to XLGB and 262 to control group) received interventions. Participants in the XLGB group exhibited significant improvement in NPRS (P < 0.001) and WOMAC score (P < 0.001) or AUSCAN score (P < 0.001) compared to control group. Treatment with XLGB at current regime significantly reduced pain and improved function of the knee and hand in patients with OA over a 6-month period, implying that XLGB could be suggested as an alternative treatment for patients with knee or hand OA.