The pathogenesis of nontraumatic osteonecrosis. Arthritis. 2012;2012:601763. [PMID: 23243507 PMCID: PMC3518945 DOI: 10.1155/2012/601763]

Potential molecular targets for the pharmacologic management of non-traumatic osteonecrosis

INTRODUCTION

Non-traumatic osteonecrosis is a debilitating condition marked by bone death, primarily due to reduced blood supply. Currently, no effective pharmacologic intervention is available to manage this condition effectively.

AREAS COVERED

Lipid metabolic disorders, chronic inflammation, vascular dysfunction, coagulopathy, and impaired bone homeostasis are suggested as the key pathogenic mechanisms involved in the development of non-traumatic osteonecrosis. Targeting any of these dysfunctions offers a potential avenue for pharmacologic intervention. However, the potential molecular targets for pharmacologic treatment of non-traumatic osteonecrosis remain underexplored. In this study, we reviewed available databases to compile a comprehensive set of pathogenic mechanisms and corresponding therapeutic targets for non-traumatic osteonecrosis.

EXPERT OPINION

Evidence suggests that a single pathogenic mechanism cannot fully explain the development of osteonecrosis, supporting the adoption of a multi-pathogenic theory. This theory implies that effective management of non-traumatic osteonecrosis requires targeting multiple pathogenic mechanisms simultaneously. Moreover, the same pathogenic mechanisms are unlikely to explain osteonecrosis development in patients with different etiologies. Consequently, a one-size-fits-all approach to medication is unlikely to be effective across all types of non-traumatic osteonecrosis. Future research should, therefore, focus on developing multi-target pharmacologic treatments tailored to the specific etiology of non-traumatic osteonecrosis.

Assessing the Impact of a Modified Core Decompression Technique on Early-Stage Avascular Necrosis of the Hip Using Bone Marrow Concentrate Adjuvant Therapy: A Retrospective Study

BACKGROUND

Osteonecrosis is characterized by the necrosis of trabecular bone and cells within the femoral head, which often results in the subchondral collapse and deformation of the articulating surface of the head. For the treatment of early stages of this condition, specifically Stage I and Stage II, bone marrow-derived stem cells have been employed effectively for several years. In our approach, we have utilized a modified technique to collect bone marrow aspirate, which has yielded favorable outcomes.

METHODS

In our study, we performed surgeries on 32 hips afflicted with early-stage osteonecrosis of the femoral head. Each patient underwent core decompression and the injection of bone marrow concentrate, guided by C-arm imaging in the operating theater. Evaluations were conducted using the Harris Hip Score and the Visual Analogue Scale (VAS), along with radiological assessments to track the progression of osteonecrosis stages before and after the surgical procedure.

RESULTS

The comparison of pre- and post-surgery data, including the Harris Hip Score, VAS, progression of osteonecrosis stages, and radiological findings, revealed significantly positive outcomes. Since May 2013, 32 hips, regardless of the etiology of avascular necrosis (AVN), have been treated with this procedure. Notably, only four patients with bilateral AVN progressed to Stage III in one hip, while the other hip remained stable. In the remaining patients, pain was alleviated, and none progressed to later stages. No complications were observed in this study.

CONCLUSION

This minimally invasive technique, characterized by its simplicity and lack of associated complications or donor site morbidity, has proven to be an effective joint-preserving surgical intervention for early stages of femoral head osteonecrosis (Stages 1 and 2).

Clinical Characteristics, Current Treatment Options, Potential Mechanisms, Biomarkers, and Therapeutic Targets in Avascular Necrosis of Femoral Head

Avascular necrosis of femoral head (AVNFH) is a debilitating disease of the young, affecting the quality of life significantly and eventually leading to total hip replacement surgery. The disease is diagnosed clinico-radiologically and MRI is the investigation of choice to diagnose the early stages of the disease. There is neither an early biomarker for detection nor is there a permanent cure for the disease and most of the patients are managed with various combinations of surgical and medical management protocols. In this review, we comprehensively address the etiopathogenesis, clinical characteristics, therapeutic procedures, bone characteristics, histopathology, multi-omic studies, finite element modeling, and systems analysis that has been performed in AVNFH. The etiology includes various factors that compromise the blood supply to the femoral head which also includes contributions by environmental and genetic factors. Multi-omic analysis has shown an association of deregulated pathways with the disease. The cell types involved include mesenchymal stem cells, osteoblasts, osteoclasts, endothelial and immune cells. Biochemical, hematological, histopathology, IHC, and other bone remodeling and degradation marker studies have been performed. A systems analysis using multi-omic data sets from published literature was carried out, the relevance of which is discussed to delineate potential mechanisms in etiopathogenesis, diagnosis, and effective management of this debilitating disease.

Altered gut microbe metabolites in patients with alcohol‑induced osteonecrosis of the femoral head: An integrated omics analysis

Excessive alcohol consumption is considered to be a major risk factor of alcohol-induced osteonecrosis of the femoral head (AONFH). The gut microbiota (GM) has been reported to aid in the regulation of human physiology and its composition can be altered by alcohol consumption. The aim of the present study was to improve the understanding of the GM and its metabolites in patients with AONFH. Metabolomic sequencing and 16S rDNA analysis of fecal samples were performed using liquid chromatography-mass spectrometry to characterize the GM of patients with AONFH and healthy normal controls (NCs). Metagenomic sequencing of fecal samples was performed to identify whether GM changes on the species level were associated with the expression of gut bacteria genes or their associated functions in patients with AONFH. The abundance of 58 genera was found to differ between the NC group and the AONFH group. Specifically, Klebsiella, Holdemanella, Citrobacter and Lentilactobacillus were significantly more abundant in the AONFH group compared with those in the NC group. Metagenomic sequencing demonstrated that the majority of the bacterial species that exhibited significantly different abundance in patients with AONFH belonged to the genus Pseudomonas. Fecal metabolomic analysis demonstrated that several metabolites were present at significantly different concentrations in the AONFH group compared with those in the NC group. These metabolites were products of vitamin B6 metabolism, retinol metabolism, pentose and glucuronate interconversions and glycerophospholipid metabolism. In addition, these changes in metabolite levels were observed to be associated with the altered abundance of specific bacterial species, such as Basidiobolus, Mortierella, Phanerochaete and Ceratobasidium. According to the results of the present study, a comprehensive landscape of the GM and metabolites in patients with AONFH was revealed, suggesting the existence of interplay between the gut microbiome and metabolome in AONFH pathogenesis.

Spontaneous bilateral avascular necrosis of knees and hip leading to early bilateral total hip arthroplasty: a case report of an 18-year-old man recently diagnosed with Crohn's disease

Avascular necrosis (AVN) is linked to considerable morbidity, resulting in severe pain and functional impairment. Herein, for the first time, we reported an 18-year-old patient with Crohn's disease during the remission phase under Azathioprine therapy who presented with articular pain. Although no underlying risk factors, the patient was diagnosed with severe AVN of the bilateral femoral head and both knees simultaneously following pain in involved areas. This case highlights the importance of demand multidisciplinary approach to chronic disease. Moreover, clinicians should be aware of articular manifestations in IBD patients to diagnose and treat these conditions as soon as possible. Patients should be evaluated for their psychologic, gastrointestinal, and extra-gastrointestinal comorbidities during each follow-up visit.

Conversion Total Hip Arthroplasty After Failed Pedicled Peri-Hip Bone Flap Grafting: The Chinese Experience

BACKGROUND

This study investigated the perioperative outcomes of patients undergoing conversion total hip arthroplasty (THA) after failed peri-hip bone flap grafting (PBFG) and compared them with those patients undergoing primary THA for osteonecrosis of the femoral head (ONFH).

METHODS

From January 2010 to December 2021, 163 Chinese patients (163 hips) were treated by conversion THA after failed PBFG (containing 94 patients who had pedicled vascularized iliac bone flap grafting and 69 patients who had pedicled vascularized greater trochanter bone flap grafting), and 178 Chinese patients were treated by primary THA. The preoperative baseline data and perioperative indicators in both groups were compared.

RESULTS

In the conversion group, patients had significantly greater blood loss, a longer length of stay, and greater changes in serum hemoglobin than those in the primary THA group (P < 0.05). The operative room time, transfusion volume, calculated blood loss, changes in serum hematocrit, and increased superficial infection (P > 0.05) in the conversion group were greater compared with the primary cohort; however, the difference was not statistically significant. The mean postoperative Harris Hip Scoring System (HHS) of the PBFG group at the one-month follow-up was 81, and the control group had an 82 score. Importantly, subgroup analysis of the PBFG group indicated that there was no significant difference between patients who had prior pedicled vascularized iliac bone flap grafting and pedicled vascularized greater trochanter bone flap grafting (P > 0.05), except for the operative room time (P = 0.032).

CONCLUSION

Hip-sparing surgery of ONFH did not make THA more difficult or lead to more peri-operative complications, but increased blood loss and extended hospital stay from a prior PBFG are still notable problems in clinical practice. Thus, it is necessary for surgeons to focus attention on the improvement of the preoperative condition and prepare for any specific intraoperative challenges.

Risk of avascular necrosis in patients with inflammatory bowel disease: Insights from a nationwide cohort study and the impact of corticosteroid use

BACKGROUND AND AIM

Corticosteroid use is a risk factor for avascular necrosis (AVN) and inflammatory bowel disease (IBD) patients are often exposed to higher corticosteroid usage. We investigated the epidemiology and risk factors of AVN in a nationwide population-based cohort of IBD patients.

METHODS

Patients newly diagnosed with IBD were identified, and sex- and age-matched participants from the general population were selected in a 1:3 IBD:non-IBD ratio. We investigated newly diagnosed AVN and assessed the incidence rates and risk of AVN with multivariate Cox regression models.

RESULTS

During the median follow-up period of 7.22±3.85 years, 357 (0.62 %) were newly diagnosed with AVN. The risk of AVN was higher in IBD (aHR = 1.42, 95 % CI: 1.25-1.62). Ulcerative colitis (UC) patients showed a particularly elevated risk of developing AVN. IBD patients with higher cumulative corticosteroid intake and exposed to a mean prednisolone-equivalent daily dose>20 mg for >1 month were at higher risk of AVN. In Crohn's disease (CD), longer exposure time to >20 mg prednisolone-equivalent presented a trend in increased risk.

CONCLUSION

AVN risk was higher in IBD than in those without, particularly in UC and corticosteroid use in IBD could pose a crucial role. These underscore the importance of considering the AVN etiological factors, particularly corticosteroid use.

Obesity impairs revascularization and bone healing in a mouse model of osteonecrosis

Osteonecrosis of the femoral head (ONFH) is a devastating bone disease that is caused by a disruption of blood supply leading to necrotic cell death. Clinically, it was found that obesity has a high prevalence with ONFH. However, it remains unclear how obesity may directly affect tissue regeneration and bone healing in osteonecrosis (ON). The purpose of this study is to investigate the effects of obesity and weight loss (WL) on ON healing. In this study, we induced obesity and WL in an established surgery-induced ON mouse model via feeding a high-fat diet (HFD) and altering the diet respectively. All mice received a surgical induction of ON of distal femoral epiphysis at the age of 12 weeks. HFD was switched to normal diet (ND) after ON surgery to induce WL. Mouse body weight was recorded weekly. Mouse body composition was scanned by DEXA (Dual-energy X-ray absorptiometry) right after sacrifice at the age of 16 weeks. The distal femoral bone samples were fixed and embedded for histology such as H&E, immunohistochemistry, and TRAP staining. In this study, we found that HFD-induced obesity impaired revascularization and bone remodeling showing decreased vessel areas and reduced osteoblast and osteoclast numbers. WL could rescue obesity-induced bone healing defects. Our study is the first to test the direct effects of obesity and WL on ON bone healing. We believe our work may provide new concepts for osteonecrosis treatment in obese patients.

The Septic Elbow Joint: Treatment Approaches for Improved Patient Outcomes

Septic arthritis of the elbow is a serious problem requiring prompt, accurate diagnosis and urgent surgical intervention. Achieving successful patient outcomes depends heavily on early diagnosis and efficient streamlined surgical treatment. Essential tactics for treating the septic elbow joint include immediate joint irrigation and debridement in addition to administration of appropriate antibiotics. This comprehensive review delves into the cause of the septic elbow joint, identifies associated risk factors, and provides a comprehensive approach encompassing the diagnosis and treatment of the septic elbow. The aim of this review is to optimize patient care and outcomes.

A Network Pharmacology Approach and Validation Experiments to Investigate the Mechanism of Wen-Dan Decoction in the Treatment of SINFH

INTRODUCTION

Steroid-induced necrosis of the femoral head (SINFH) is a femoral head necrotic disease caused by prolonged use of hormones. Wen-Dan decoction is used in Chinese clinical practice for the treatment of steroid-induced necrosis of the femoral head (SINFH). However, the mechanism and active compounds of Wen-Dan decoction used to treat SINFH are not well understood.

OBJECTIVES

We studied the mechanism of action of Wen-Dan decoction in treating steroidinduced necrosis of the femoral head (SINFH) via network pharmacology and in vivo experiments.

METHODS

The active compounds of Wen-Dan decoction and SINFH-related target genes were identified through public databases. Then, network pharmacological analysis was conducted to explore the potential key active compounds, core targets and biological processes of Wen-Dan decoction in SINFH. The potential mechanisms of Wen-Dan decoction in SINFH obtained by network pharmacology were validated through in vivo experiments.

RESULTS

We identified 608 DEGs (differentially expressed genes) (230 upregulated, 378 downregulated) in SINFH. GO analysis revealed that the SINFH-related genes were mainly involved in neutrophil activation and the immune response. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis showed that the SINFH-related genes were mainly associated with cytokine receptor interactions, lipids, atherosclerosis, and tuberculosis. We identified 147 active ingredients of Wen-Dan decoction; the core ingredient was quercetin, and licorice was an active ingredient. Moreover, 277 target genes in the treatment of SINFH with Wen-Dan decoction were identified, and NCF1, PTGS2, and RUNX2 were selected as core target genes. QRT-PCR of peripheral blood from SINFH patients showed higher levels of PGTS2 and NCF1 and showed lower levels of RUNX2 compared to controls. QRT-PCR analysis of peripheral blood and femoral bone tissue from a mouse model of SINFH showed higher levels of PGTS2 and NCF1 and lower levels of RUNX2 in the experimental animals than the controls, which was consistent with the bioinformatics results. HE, immunohistochemistry, and TUNEL staining confirmed a significant reduction in hormone-induced femoral head necrosis in the quercetintreated mice. HE, immunohistochemistry, and TUNEL staining confirmed significant improvement in hormone-induced femoral head necrosis in the quercetin-treated mice.

CONCLUSION

We provide new insights into the genes and related pathways involved in SINFH and report that PTGS2, RUNX2, and NCF1 are potential drug targets. Quercetin improved SINFH by promoting osteogenesis and inhibiting apoptosis.

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.

Investigating the subchondral trabecular bone microstructure in patients with osteonecrosis of the femoral head using multi-detector row computed tomography

OBJECTIVES

To analyse the microstructural changes of subchondral trabecular bone in patients with osteonecrosis of the femoral head (ONFH) using multi-detector row computed tomography (MDCT).

METHODS

We retrospectively investigated 76 hips in 50 patients diagnosed with ONFH between 2017 and 2021. Groups 1, 2, 3, and 4 comprised hips without ONFH, ONFH without femoral head collapse (FHC), ONFH with mild collapse (<2 mm), and ONFH with severe collapse (>2 mm), respectively. All patients underwent MDCT, and the subchondral trabecular bone microstructure was assessed. Regions of interests were set at the lateral boundary of the femoral head necrotic lesion and centre of the acetabular weight-bearing portion.

RESULTS

In both the femoral head and the acetabular regions, there were significant differences in Groups 2 and 3 compared to Group 1, with increased volumetric bone mineral density and apparent bone volume fraction, and more plate-like with increased connectivity, indicating that osteosclerotic changes were occurring.

CONCLUSIONS

In both the femoral head and the acetabular regions, osteosclerotic changes of subchondral trabecular bone microstructure were present before FHC.

Core decompression is superior to nonoperative management for humeral head osteonecrosis: a systematic review

BACKGROUND

Much of the literature on osteonecrosis has traditionally focused on the hip, which remains the most common site for this disease. The shoulder and the knee are the second most frequently affected sites (both approximately 10% of the incidence). There are a variety of techniques for managing this disease, and it is important to optimize this for our patients. This review aimed to compare the results of core decompression (CD) vs. nonoperative modalities for the treatment of osteonecrosis of the humeral head, including (1) success rate defined as lack of progression to further procedures (shoulder arthroplasty) and no need for further intervention; (2) clinical results (patient-reported pain and functional scores); and (3) radiological outcomes.

METHODS

We queried PubMed and found 15 reports that fit the inclusion criteria for studies concerning the use of CD as well as studies discussing nonoperative treatment for stage I-III osteonecrotic lesions of the shoulder. A total of 9 studies encompassed 291 shoulders that underwent CD analyzed at a mean follow-up of 8.1 years (range, 67 months-12 years), and 6 studies examined 359 shoulders that underwent nonoperative management at a mean follow-up of 8.1 years (range, 35 months-10 years). Outcomes of CD and nonoperative management included success rate, number of shoulders requiring shoulder arthroplasty, and evaluation of several normalized patient-reported outcomes. We also assessed radiographic progression (pre- to postcollapse or further collapse progression).

RESULTS

The mean success rate of CD for avoiding further procedures was 76.6% (226 of 291 shoulders) in stage I through stage III. Stage III shoulders avoided shoulder arthroplasty in 63% (27 of 43 shoulders). Nonoperative management resulted in a success rate of 13%, P < .001. In the CD studies, 7 of 9 showed improvements in clinical outcome measurements compared with 1 of 6 of the nonoperative studies. Radiographically, there was less progression in the CD group (39 of 191 shoulders [24.2%]) vs. the nonoperative group (39 of 74 shoulders [52.3%]) (P < .001).

CONCLUSIONS

Given the high success rate and positive clinical outcomes reported, CD is an effective method for management, especially when compared with nonoperative treatment methods for stage I-III osteonecrosis of the humeral head. The authors believe that it should be used as treatment to avoid arthroplasty in patients who have osteonecrosis of the humeral head.

Updating Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH), a condition characterized by the presence of a necrotic bone lesion in the femoral head, is caused by a disruption in the blood supply. Its occurrence is more common in young and middle-aged adults and it is the main reason for performance of total hip arthroplasty in this age group. Its incidence is increasing along with increased use of glucocorticoids for management of adjuvant therapy for treatment of leukemia as well as organ transplantation and other myelogenous diseases. Current information on etiology and pathogenesis, as well as natural history, stage system, and treatments is provided in this review. A description of the Association Research Circulation Osseous (ARCO) criteria for classification of glucocorticoids- and alcohol-associated ONFH, 2019 ARCO staging system, and 2021 ARCO classification using computed tomography for the early stages of ONFH is also provided.

Chromolaena odorata (L.) R. M. King and H. Robinson Leaves Aqueous Extract Improves the Femoral Head in Ethanol-Induced Osteonecrosis in Rats

Chronic alcohol consumption damages bone formation and causes bone pathology, including osteonecrosis of the femoral head. The aim of this work was to evaluate the effects of the leaf aqueous extract of Chromolaena odorata (C. odorata) on the femoral head in ethanol-induced osteonecrosis in rats. Animals received alcohol (40°) at 3 g/kg for 12 weeks. A group of animals were sacrificed to attest to the instalment of osteonecrosis by using histopathological analysis. The remaining animals received alcohol concomitantly with the plant extract (150, 300, or 600 mg/kg) or diclofenac (1 mg/kg) for 28 additional days. At the end of the experimental period, biochemical parameters including total cholesterol, triglycerides, calcium, alkaline phosphatase (ALP), reduced glutathione (GSH), malondialdehyde (MDA), nitrite, superoxide dismutase (SOD), and catalase activities were measured. Histopathological and histomorphometry analyses of femurs were also assessed. The administration of alcohol, irrespective of the experimental period, induced a significant increase in total cholesterol (p < 0.05) and triglyceride (p < 0.01) and a decrease in ALP (p < 0.05) and calcium (p < 0.05-p < 0.001) levels. Intoxicated animals showed an alteration in oxidative stress parameters accompanied by a significant drop in bone cortical thickness and density with necrosis and marked bone resorption. The concomitant administration of the plant with ethanol reversed the alcohol-induced bone defect, characterized by the improvement of the lipid profile (p < 0.001), bone calcium concentration (p < 0.05), bone ALP activity (p < 0.001), oxidative stress parameters, improved cortical bone thickness (p < 0.01), and bone density (p < 0.05). These results are supported by the absence of bone resorption with an obvious effect at a dose of 300 mg/kg. The pharmacological effect of the extract on ethanol-induced osteonecrosis of the femoral head is probably due to its osteogenic, hypolipidemic, and antioxidant properties, justifying its use in Cameroonian folk medicine for articulation and bone pain management.

Phase-contrast imaging with synchrotron hard X-ray reveals the effect of icariin on bone tissue morphology and microstructure in rabbits with early glucocorticoid-induced osteonecrosis of the femoral head

Background: Phase-contrast imaging (PCI) with synchrotron hard X-ray was used to observe the changes in bone tissue morphology and microstructure in rabbit models of early glucocorticoid-induced osteonecrosis of the femoral head (ONFH), and to evaluate the intervention effect of Icariin. Methods: Fifty mature New Zealand rabbits (weighing 2.5-3.0 kg) were randomly divided into a control group (n = 10), a glucocorticoid group (n = 20), and an Icariin group (n = 20). The glucocorticoid group and the Icariin group were sequentially injected with lipopolysaccharide (LPS) and methylprednisolone (MPS) to establish a glucocorticoid-induced ONFH animal model. The Icariin group was given Icariin solution when methylprednisolone was injected for the first time, and the control group and glucocorticoid group were given the same amount of normal saline. Animals were sacrificed after 6 weeks, and bilateral femoral head specimens were taken for research. The right femoral head was observed by PCI with synchrotron hard X-ray technology, and the left femoral head was verified by Micro-CT scanning and HE staining. Results: Forty-three animals (nine in the control group, sixteen in the glucocorticoid group, and eighteen in the Icariin group) were included in the study. PCI with synchrotron hard X-ray revealed that the trabecular bone in the glucocorticoid group was thinned, broken, and structurally damaged, whereas the trabecular bone in the Icariin group had normal volume, thickness, and a relatively intact structure. Micro-CT scan reconstruction and HE staining were used to verify the reliability of this technique in identifying osteonecrosis. Conclusion: The effects of Icariin were observed in an early glucocorticoid-induced ONFH rabbit model using PCI with synchrotron hard X-ray. Icariin weakens the destructive effect of glucocorticoids on bone tissue structure, improves bone tissue morphology, and stabilizes bone microstructure. This technique may provide a definitive, non-invasive alternative to histological examination for the diagnosis of early ONFH.

Dose-Response Meta-Analysis of Corticosteroid Effects in SARS Outbreak: A Model for Risk Stratification and Screening Strategy for Osteonecrosis of Femoral Head Post-Corticosteroid Therapy for COVID-19

Corticosteroids (CS) have been used in the management regimens for COVID-19 disease to mitigate the cytokine storm and ill effects of the pulmonary inflammatory cascade. With the rampant use of CS, clinicians started reporting the occurrence of osteonecrosis of the femoral head (OFH). In this systematic review, we aim to analyze the literature and identify the definitive cumulative dose and duration of CS needed for the development of OFH based on the SARS model and generate a risk-based screening recommendation for OFH in convalescent COVID-19 patients to facilitate early identification and management. An electronic database search was conducted until December 2022 in PubMed, Web of Science, Embase, and CNKI (China Knowledge Resource Integrated Database). Studies involving CS therapy and osteonecrosis data in SARS patients were included. Three authors independently extracted the data from the included studies and a dose-response meta-analysis was performed for various doses and duration of CS utilized in the included studies. We selected 12 articles with 1728 patients in the analysis. The mean age was 33.41 (±4.93) years. The mean dosage of CS administered was 4.64 (±4.7) g which was administered for a mean duration of 29.91 (±12.3) days. The risk of osteonecrosis increases at pooled OR of 1.16 (95% CI 1.09-1.23, p < 0.001) per 2.0 g increase in the cumulative dose of CS usage. Similarly, the risk increases at pooled OR of 1.02 (95% CI 1.01-1.03, p < 0.001) per 5 days of increase in the cumulative duration of CS usage. A cumulative dosage of 4 g and a duration of 15 days were determined as the critical cut-off for the non-linear dose-response relationship observed. Appropriate and frequent screening of these individuals at regular intervals would help in the identification of the disease at an early stage in order to treat them appropriately.

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.

Relationship of idiopathic femoral head necrosis with blood lipid metabolism and coagulation function: A propensity score-based analysis

Background

Nontraumatic osteonecrosis of the femoral head (ONFH) can be corticosteroid-induced, alcohol-induced, and idiopathic ONFH (IONFH). Although corticosteroid- and alcohol-induced ONFH has been investigated extensively regarding its relationship with blood lipids and coagulation factor levels. However, the effect of blood lipid metabolism and coagulation function on IONFH has rarely been studied. Therefore, this study aimed to analyse the relationship of IONFH with blood lipid and coagulation indicators.

Methods

Total 680 patients diagnosed with IONFH in our institution during January 2011-June 2019 who met the inclusion criteria composed the case group; 613 healthy persons who underwent physical examination at our institution during the same period composed the control group. Propensity scores were used for baseline feature matching, and two matching groups each with 450 patients were established. After the matching, blood lipid and coagulation factor levels of both groups were comparatively analysed.

Results

The case group showed significantly higher total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) levels, low-density/high-density lipoprotein (LDL/HDL) ratio, and apolipoprotein B (Apo-B) levels than the control group (p < 0.05). Conversely, the HDL and apolipoprotein A (Apo-AI) levels in the case group were significantly lower than those in the control group (p < 0.05). Regarding coagulation indicators, the activated partial thromboplastin time and prothrombin time were lower in the case group than in the control group; however, the differences were insignificant (p > 0.05). Furthermore, fibrinogen (FIB) levels and thrombin time (TT) in the case group were higher than those in the control group. There were significant differences between the two groups only in terms of FIB levels (p < 0.05), while TT was not significantly different (p > 0.05).

Conclusions

IONFH has strong associations with blood lipid metabolism and coagulation function, which provide an avenue for exploring the mechanism of IONFH.

Less sclerotic microarchitecture pattern with increased bone resorption in glucocorticoid-associated osteonecrosis of femoral head as compared to alcohol-associated osteonecrosis of femoral head

BACKGROUND

Glucocorticoid usage and alcohol abuse are the most widely accepted risk factors for nontraumatic osteonecrosis of femoral head (ONFH). Despite distinct etiologies between glucocorticoid-associated ONFH (GONFH) and alcohol-associated ONFH (AONFH), little is known about the differences of the microarchitectural and histomorphologic characteristics between these subtypes of ONFH.

PURPOSES

To investigate bone microarchitecture, bone remodeling activity and histomorphology characteristics of different regions in femoral heads between GONFH and AONFH.

METHODS

From September 2015 to October 2020, 85 patients diagnosed with GONFH and AONFH were recruited. Femoral heads were obtained after total hip replacement. Femoral head specimens were obtained from 42 patients (50 hips) with GONFH and 43 patients (50 hips) with AONFH. Micro-CT was utilized to assess the microstructure of 9 regions of interest (ROIs) in the femoral head. Along the supero-inferior orientation, the femoral head was divided into necrotic region, reactive interface, and normal region; along the medio-lateral orientation, the femoral head was divided into medial region, central region and lateral region. Decalcified and undecalcified bone histology was subsequently performed to evaluate histopathological alterations and bone remodeling levels.

RESULTS

In the necrotic region, most of the microarchitectural parameters did not differ significantly between GONFH and AONFH, whereas both the reactive interface and normal region revealed a less sclerotic microarchitecture but a higher bone remodeling level in GONFH than AONFH. Despite similar necrotic pathological manifestations, subchondral trabecular microfracture in the necrotic region was more severe and vasculature of the reactive interface was more abundant in GONFH.

CONCLUSIONS

GONFH and AONFH shared similar microarchitecture and histopathological features in the necrotic region, while GONFH exhibited a less sclerotic microarchitecture and a more active bone metabolic status in both the reactive interface and normal region. These differences between GONFH and AONFH in bone microarchitectural and histopathological characteristics might contribute to the development of disease-modifying prevention strategies and treatments for ONFH, taking into etiologies.

Avascular necrosis of the epiphyses of bones in patients who have had SARS-CoV-2 infection: Clinical observations and a narrative review of literature data

The SARS-CoV-2 coronavirus pandemic is a leading medical problem that is in the focus of attention of representatives of all medical specialties. In addition to fighting the COVID-19 infection itself, the task of preventing and treating a wide range of complications arising after the disease is becoming increasingly urgent. One of these complications is avascular necrosis (AN) of bone tissue – a severe pathology that leads to serious suffering, a decrease in the quality of life and disability of patients. For the period from 2020 to 2022 there are 9 reviews in the world literature devoted to the pathogenesis, clinical features and treatment possibilities of this complication. During the same period, 5 articles were published describing clinical observations of AN after suffering COVID-19.The purpose of this work is to demonstrate our own clinical observations, as well as to review the available literature data on the problem of AN after COVID-19 infection. Based on the analysis, it can be concluded that AN after SARS-CoV-2 infection most often develops in the femoral head (>50% of cases), occurs regardless of the severity of the disease and the cumulative dose of glucocorticoids used in the acute period of the disease. It seems advisable to perform an MRI of the hip joints at least once every 3 months for all patients who have had COVID-19 in severe and moderate form during the first year after convalescence.

Emerging roles of growth factors in osteonecrosis of the femoral head

Osteonecrosis of the femoral head (ONFH) is a potentially disabling orthopedic condition that requires total hip arthroplasty in most late-stage cases. However, mechanisms underlying the development of ONFH remain unknown, and the therapeutic strategies remain limited. Growth factors play a crucial role in different physiological processes, including cell proliferation, invasion, metabolism, apoptosis, and stem cell differentiation. Recent studies have reported that polymorphisms of growth factor-related genes are involved in the pathogenesis of ONFH. Tissue and genetic engineering are attractive strategies for treating early-stage ONFH. In this review, we summarized dysregulated growth factor-related genes and their role in the occurrence and development of ONFH. In addition, we discussed their potential clinical applications in tissue and genetic engineering for the treatment of ONFH.

Atraumatic osteonecrosis of the humeral head: pathophysiology and current concepts of evaluation and treatment

The humeral head is considered the second most common site for osteonecrosis to occur after the femoral head. As seen in the femoral head, the circulatory implications characteristic of this condition are attributable to the interaction between a genetic predisposition and the exposure to certain risk factors. There is no consensus regarding the pathogenesis of osteonecrosis, yet the final common pathway results in disrupted blood supply, increased intraosseous pressure, and bone death. Disease staging using radiography and magnetic resonance imaging is predictive of disease progression and can help the orthopedic surgeon to guide treatment. Although there is a myriad of treatment modalities, there is a lack of high-quality evidence to conclude what is the most appropriate treatment option for each stage of humeral head osteonecrosis. Nonoperative treatment is the preferred option in early-stage disease, and it may prevent disease progression. Nonetheless, in some cases, disease progression occurs despite nonoperative measures, and surgical treatment is required. The purpose of this article is to provide an updated review of the available evidence on risk factors, diagnosis, and treatment of atraumatic humeral head osteonecrosis.

Epidemiology and risk factors associated with avascular necrosis in patients with autoimmune diseases: a nationwide study

BACKGROUND/AIMS

Avascular necrosis (AVN) is a clinical condition characterized by the death of bone components due to interruption in the blood supply. This study aimed to investigate the epidemiology and determine the risk factors for AVN in patients with autoimmune diseases.

METHODS

We conducted a population-based retrospective cohort analysis using claims data from the Taiwan National Health Insurance Research Database. A total of 49,636 patients with autoimmune diseases between January 1, 2005 and December 31, 2013 were included. Cox regression analysis was used to identify associated risk factors for the development of AVN.

RESULTS

A total of 490/49,636 patients (1.0%) developed symptomatic AVN. The systemic lupus erythematosus patients had a higher risk of AVN compared to other autoimmune diseases. AVN was positively correlated with male sex (p < 0.001), alcoholism (p < 0.001), mean daily prednisolone dosage 7.51 to 30 mg (p < 0.001) and > 30 mg (p < 0.001), and total cumulative prednisolone dose 0 g to 5 g (p = 0.002). However, AVN was inversely correlated with cumulative duration of hydroxychloroquine exposure > 0.6 years (p < 0.001).

CONCLUSION

Male sex, systemic lupus erythematosus, alcoholism, mean daily corticosteroid > 7.5 mg and a total cumulative dose of corticosteroid 0 to 5 g were independently associated with the development of AVN in autoimmune patients. While hydroxychloroquine use > 0.6 years conferred significant protection against the development of AVN. Clinicians should regularly assess patients with risk factors to enable the early diagnosis of AVN.

Avascular Necrosis of Femoral Head-Overview and Current State of the Art

Avascular necrosis (AVN) of the femoral head is caused by disruption of the blood supply to the proximal femur. The alterations in the blood supply may occur following a traumatic event or result from a non-traumatic cause. Femoral neck fracture and hip dislocation and associated surgical procedures, corticosteroid therapy, and alcohol abuse frequently lead to AVN development. Type of fracture (displaced or undisplaced) and time between injury and surgery are the most critical factors in assessing the risk of developing AVN. Diagnosis of AVN can be established based on patients’ complaints, medical history, and radiographic findings. There is no consensus on the treatment of patients with AVN to date. Non-surgical methods are dedicated to patients in the early pre-collapse stages of the disease and consist of pharmacotherapy and physiotherapy. Surgery is recommended for patients with advanced disease.

The 2021 Association Research Circulation Osseous Classification for Early-Stage Osteonecrosis of the Femoral Head to Computed Tomography-Based Study

BACKGROUND

The Association Research Circulation Osseous developed a novel classification for early-stage (precollapse) osteonecrosis of the femoral head (ONFH). We hypothesized that the novel classification is more reliable and valid when compared to previous 3 classifications: Steinberg, modified Kerboul, and Japanese Investigation Committee classifications.

METHODS

In the novel classification, necrotic lesions were classified into 3 types: type 1 is a small lesion, where the lateral necrotic margin is medial to the femoral head apex; type 2 is a medium-sized lesion, with the lateral necrotic margin being between the femoral head apex and the lateral acetabular edge; and type 3 is a large lesion, which extends outside the lateral acetabular edge. In a derivation cohort of 40 early-stage osteonecrotic hips based on computed tomography imaging, reliabilities were evaluated using kappa coefficients, and validities to predict future femoral head collapse by chi-squared tests and receiver operating characteristic curve analyses. The predictability for future collapse was also evaluated in a validation cohort of 104 early-stage ONFH.

RESULTS

In the derivation cohort, interobserver reliability (k = 0.545) and intraobserver agreement (63%-100%) of the novel method were higher than the other 3 classifications. The novel classification system was best able to predict future collapse (P < .05) and had the best discrimination between non-progressors and progressors in both the derivation cohort (area under the curve = 0.692 [0.522-0.863], P < .05) and the validation cohort (area under the curve = 0.742 [0.644-0.841], P = 2.46 × 10^-5).

CONCLUSION

This novel classification is a highly reliable and valid method of those examined. Association Research Circulation Osseous recommends using this method as a unified classification for early-stage ONFH.

LEVEL OF EVIDENCE

Level III, diagnostic study.

The Combined Use of Platelet-Rich Plasma Clot Releasate and Allogeneic Human Umbilical Cord Mesenchymal Stem Cells Rescue Glucocorticoid-Induced Osteonecrosis of the Femoral Head

Glucocorticoid-induced osteonecrosis of the femoral head (ONFH) is a refractory disease. The treatment options for ONFH, especially nonsurgical ones, merit further investigation. To evaluate the combinatorial therapeutic effects of platelet-rich plasma clot releasate (PRCR) and umbilical cord mesenchymal stem cells (UC-MSCs) on glucocorticoid-induced ONFH, a dexamethasone (DEX)-treated cell model and a high-dose methylprednisolone (MPS)-treated rat model were established. Cell counting kit-8 (CCK-8) assay was performed in vitro to determine the optimum dosage of PRCR for UC-MSC viability. The effects of PRCR, UC-MSCs, and PRCR + UC-MSCs on cell viability, apoptosis, migration, and differentiation capacities of DEX-treated bone marrow mesenchymal stem cells (BMSCs) and human umbilical vein endothelial cell (HUVECs) were explored via Transwell assays. Western blotting was conducted to evaluate the expression levels of RUNX2, VEGF, caspase-3, and Bcl-2 in the coculture systems. Ultrasound-guided intra-articular PRCR, UC-MSCs, and PRCR + UC-MSC injections were performed on the ONFH model rats. Microcomputed tomography, histological and immunohistochemical analyses, tartrate-resistant acid phosphatase (TRAP) staining, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining were used to assess the therapeutic effects of PRCR and UC-MSCs on bone loss and necrosis induced by high-dose MPS. Results of this study revealed that the in vitro application of PRCR, UC-MSCs, and PRCR + UC-MSCs reversed the impaired proliferation and migration capacities and resisted apoptosis of BMSCs and HUVECs induced by DEX. Moreover, the PRCR and UC-MSC application significantly improved the alkaline phosphatase (ALP) and alizarin red (ALR) staining of BMSCs and tube formation capacity of HUVECs and promoted the protein expression of RUNX2 in BMSCs and VEGF in HUVECs. Similarly, in the ONFH rat model, the intra-articular injection of UC-MSCs and PRCR improved the subchondral bone mass parameters; promoted the expression of ALP, RUNX2, and VEGF; suppressed osteoclast overactivity; and resisted cell apoptosis. The combination of PRCR and UC-MSCs shows promising therapeutic effects in treating glucocorticoid-induced ONFH. The current study provides important information on intra-articular therapy, paving the way for the clinical management of ONFH in the future.

Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head is a progressive and debilitating condition with a wide variety of etiologies including trauma, steroid use, and alcohol intake. Diagnosis and staging are based on imaging including MRI at any stage and plain radiography in more advanced lesions. The only definitive treatment is total hip arthroplasty, although numerous treatments including disphosphonates and core decompression are used to delay the progression. Lack of satisfactory conservative measures suggests the need for additional research of osteonecrosis including large patient registries to further understand this condition.

Core Decompression and Bone Marrow Aspiration Concentrate Grafting for Osteonecrosis of the Femoral Head

BACKGROUND

Core decompression (CD) with bone marrow aspiration concentrate (BMAC) is a technique that may improve outcomes in osteonecrosis of the femoral head (ONFH). The primary aim of this study was to evaluate the radiographic progression free survival (PFS) of CD augmented with BMAC. Secondary aims were to determine the survivorship with conversion (CFS) to total hip arthroplasty (THA) as an endpoint, determine prognostic factors, and characterize the cellular quality of the BMAC.

METHODS

A retrospective cohort study of 61 femoral heads (40 patients) was performed. Patient demographics, comorbidities, BMI, smoking status, etiology, location and extent of ONFH were recorded. The primary endpoint was radiographic progression of ONFH and secondarily, conversion to THA. Additional aims were to determine predictive factors for progression and report the cellular characteristics of the BMAC. Data obtained were compared to the results of a prior randomized controlled trial comparing CD alone versus CD with polymethylmethacrylate cement (PMMA) augmentation.

RESULTS

Radiographic PFS of CD with BMAC at 2 and 5 years was 78.3% and 53.3%, respectively. The risk of progression was lower in the CD with BMAC group compared to CD alone (HR0.45, p = 0.03), however this difference no longer remained statistically significant on multivariate analysis. Conversion to total hip arthroplasty free survival (CFS) of CD with BMAC at both 2 and 5 years was 72.1% and 54.6%, respectively with no differences compared to the control groups (CD alone, CD and PMMA). The predictive factors for progression were obesity (BMI ≥ 30) and the extent of the disease as quantified by either percentage involvement, necrotic index or modified necrotic index.

CONCLUSIONS

No differences in PFS or CFS between CD with BMAC compared to CD alone or CD with PMMA were identified. Independent statistically significant predictors of progression-free survival or conversion to THA are BMI ≥ 30 and the extent of ONFH. Further research with an adequately powered randomized controlled trial is needed.

LEVEL OF EVIDENCE

3.

Risk Factors and Outcomes Associated with Intraoperative Fractures during Short-Stem Total Hip Arthroplasty for Osteonecrosis of the Femoral Head

Background

Young age in osteonecrosis of the femoral head (ONFH) demands bone-preserving, short-stem arthroplasty. Several designs including neck-preserving stems and neck-resecting, shortened, standard stems are classified as short stems. There is a paucity of literature investigating risk factors and outcomes of intraoperative complications of neck preserving, short-stem arthroplasty in ONFH.

Methods

A total of 107 hips operated with METHA short-stem arthroplasty for ONFH were retrospectively evaluated. The mean age of patients was 43.7 years (range, 27–60 years). Nine patients had an intraoperative fracture. Seven hips received prophylactic cerclage wiring for poor bone quality. Patients were invited for clinical and radiological evaluation at the latest follow-up.

Results

The mean follow-up of patients was 47.2 months. Significant association with intraoperative fractures and the need for prophylactic cerclage wiring were found in steroids-, alcohol-, and chronic renal failure-induced ONFH. However, patient sex, body mass index, traumatic/idiopathic ONFH, previous implant in situ, prosthesis size, and single-sitting bilateral total hip replacement (THA) were not the risk factors. All hips showed signs of osteointegration at final follow-up. No revision was done during the study period for any cause.

Conclusions

METHA short-stem THA offers excellent functional and radiological outcomes in ONFH. However, precaution must be exercised in patients with steroids-, alcohol-, and renal disorders-induced ONFN due to poor bone quality and higher chances of intraoperative fractures. Also, additional measures such as the use of a high-speed burr and prophylactic cerclage wiring in ONFH may allow predictable and safe use of short stems.

The Emerging Role of MicroRNAs in Bone Diseases and Their Therapeutic Potential

MicroRNAs (miRNAs) are a class of small (20-24 nucleotides), highly conserved, non-coding RNA molecules whose main function is the post-transcriptional regulation of gene expression through sequence-specific manners, such as mRNA degradation or translational repression. Since these key regulatory molecules are implicated in several biological processes, their altered expression affects the preservation of cellular homeostasis and leads to the development of a wide range of pathologies. Over the last few years, relevant investigations have elucidated that miRNAs participate in different stages of bone growth and development. Moreover, the abnormal expression of these RNA molecules in bone cells and tissues has been significantly associated with the progression of numerous bone diseases, including osteoporosis, osteosarcoma, osteonecrosis and bone metastasis, among others. In fact, miRNAs regulate multiple pathological mechanisms, including altering either osteogenic or osteoblast differentiation, metastasis, osteosarcoma cell proliferation, and bone loss. Therefore, in this present review, aiming to impulse the research arena of the biological implications of miRNA transcriptome in bone diseases and to explore their potentiality as a theragnostic target, we summarize the recent findings associated with the clinical significance of miRNAs in these ailments.

Osteonecrosis in systemic lupus erythematosus: Systematic insight from the epidemiology, pathogenesis, diagnosis and management

Osteonecrosis (ON) is one of the serious and well recognized complicationscausing severe pain and disability in patients with systemic lupus erythematosus (SLE), and its manifestation and pathogenesis are only partially understood. This review provide an update of the recent progress in etiology, pathogenesis, diagnosis, and treatment of systemic lupus erythematosus related osteonecrosis (SLE-ON). Despite the concomitant use of corticosteroids, alcohol and obesity, the dysregulated immune micro-environment and the complex pathogenesis of SLE synergistically play important roles in the development of ON. Osteonecrosis of femoral head (ONFH) is the most often involved joint in SLE. The current classification and staging system of ONFH is based on imaging techniques, particularly relating to MRI and CT, for the identification and quantification of necrotic lesions. For SLE-ONFH patients, both SLE specific clinical symptoms and ONFH imaging findings should be comprehensively evaluated. Even though advances concerning bone grafting and arthroplasty procedures have resulted in improved clinical outcomes, early pharmacological treatment at the pre-collapse stage may prevent joint collapse and reduce the joint arthroplasty rate, and this needs to be accounted. Although some progress has been made, considerably more research is needed before we fully understand SLE-ONFH. Future treatments of SLE-ONFH may involve genetic or cell-based therapies that target potential biomarkers, and this will lead to effective measures for saving thefunction of hip joint and preventing osteonecrosis.

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.

Study of Icaritin Films by Low-Energy Electron Beam Deposition

In this paper, icaritin film was prepared by low-energy beam electron beam deposition (EBD). The material test showed that the structure and composition of icaritin were not changed after electron beam deposition. Then, the film was sliced and immersed in simulated body fluids, it can be seen that the film was released quickly in the first 7 days. With the extension of soaking time, the release rate gradually slowed down, and the release amount exceeded 90% in about 20 days. In vitro cytotoxicity test showed that the relative cell viability rate of the film was still 92.32±1.30% (p<0.05), indicating that the film possessed excellent cytocompatibility.

RAB40C Gene Polymorphisms Were Associated with Alcohol-Induced Osteonecrosis of the Femoral Head

Introduction

Alcohol-induced osteonecrosis of the femoral head (ONFH), a progressive disease, is caused by excessive drinking and genetic factors. Currently, it remains to represent a significant challenge. The association between alcohol-induced ONFH and RAB40C gene polymorphisms may provide a direction for the mechanism of alcoholic ONFH.

Methods

A total of 201 alcohol-induced ONFH patients and 201 healthy controls were recruited in this case–control study. The polymorphisms of RAB40C gene were genotyped in blood samples by Agena MassARRAY RS1000. Pearson chi-square test was used to calculate difference in allele frequencies of gene polymorphisms between the cases and controls. Alcohol-induced ONFH risk was estimated using odds ratios (ORs) and 95% confidence intervals (CIs).

Results

In the overall analysis, the allele “G” of rs62030917 was significantly increased alcohol-induced ONFH risk (OR = 1.47, 95% CI = 1.07–2.02, p = 0.017) in the allele model. In the genetic analysis, rs62030917 also increased the risk of alcohol-induced ONFH in the dominant model (adjusted OR = 1.52, 95% CI=1.02–2.26, p = 0.039) and the log-additive model (adjusted OR = 1.42, 95% CI=1.05–1.93, p = 0.025). Age stratification analysis suggested that rs62030917 increased the risk of alcohol-induced ONFH among the individuals younger than 42 years old. Moreover, carriers of AA, GA and GG genotypes in rs2269556 had LDL-C levels that were significantly different (p = 0.047). Among them, carriers of GG genotype had the highest LDL-C levels.

Conclusion

This study revealed rs62030917 in RAB40C gene might increase the risk of alcohol-induced ONFH, providing a theoretical basis for the mechanism of RAB40C in alcohol-induced ONFH.

Histopathological and immunohistochemical aspects of bone tissue in aseptic necrosis of the femoral head

Femoral head osteonecrosis, also known as avascular necrosis, is a disease with a multifactorial etiology, characterized by a profound change of bone architecture, which leads to the diminishing of bone resistance and femoral head collapse. The main causes that lead to femoral head necrosis are represented by the decrease of local blood perfusion and increase of intraosseous pressure, because of an excessive development of adipose tissue in the areolas of the trabecular bone tissue in the femoral head. The histopathological and immunohistochemical (IHC) study performed by us showed that most of bone trabeculae were damaged by necrotic-involutive processes, their sizes being reduced, both regarding their length and their diameter; generally, the spans were thin, fragmented, distanced among them, which led to the occurrence of some large areolar cavities, full of conjunctive tissue, rich in adipocytes. Some of the residual bone spans even presented microfractures. In the structure of the trabecular bone tissue, numerous cavities showed lack of content, which indicates the death of osteocytes inside, while the endosteum appeared very thin, with few osteoprogenitor, flattened, difficult to highlight cells. The IHC study showed a low reaction of the bone reparatory processes and a reduced multiplication capacity of bone cells involved in the remodeling and remake of the diseased bone tissue. Nevertheless, there were identified numerous young conjunctive cells (fibroblasts, myofibroblasts), positive to proliferating cell nuclear antigen (PCNA), cells that have a high capacity of multiplication, participating in the formation of a fibrous conjunctive tissue (sclerous) instead of the damaged bone trabeculae. The formation of fibrous conjunctive tissue causes the reduction of mechanical resistance of the femoral head and its collapse. The IHC study of the microvascularization in the femoral head damaged by aseptic osteonecrosis showed the presence of a very low vascular system, both in the residual bone trabeculae and in the sclerous conjunctive tissue. Of the inflammatory cells present in the spongy bone tissue of the femoral head affected by osteonecrosis, the most numerous ones were the macrophages. Both macrophages and T- and B-lymphocytes had a heterogenous distribution.

Osteonecrosis of the Femoral Head: an Updated Review of ARCO on Pathogenesis, Staging and Treatment

Non-traumatic osteonecrosis of the femoral head (ONFH) usually affects adults younger than 50 years and frequently leads to femoral head collapse and subsequent arthritis of the hip. It is becoming more prevalent along with increasing use of corticosteroids for the adjuvant therapy of leukemia and other myelogenous diseases as well as management of organ transplantation. This review updated knowledge on the pathogenesis, classification criteria, staging system, and treatment of ONFH.

Integrating Transcriptome-Wide Association Study and mRNA Expression Profiling Identifies Novel Genes Associated With Osteonecrosis of the Femoral Head

Objective

This study aims to identify novel candidate genes associated with osteonecrosis of the femoral head (ONFH).

Methods

A transcriptome-wide association study (TWAS) was performed by integrating the genome-wide association study dataset of osteonecrosis (ON) in the UK Biobank with pre-computed mRNA expression reference weights of muscle skeleton (MS) and blood. The ON-associated genes identified by TWAS were further subjected to gene ontology (GO) analysis by the DAVID tool. Finally, a trans-omics comparative analysis of TWAS and genome-wide mRNA expression profiling was conducted to identify the common genes and the GO terms shared by both DNA-level TWAS and mRNA-level expression profile for ONFH.

Results

TWAS totally identified 564 genes that were with P_TWAS value <0.05 for MS and blood, such as CBX1 (P_TWAS = 0.0001 for MS), SRPK2 (P_TWAS = 0.0002 for blood), and MYO5A (P_TWAS = 0.0005 for blood). After comparing the genes detected by TWAS with the differentially expressed genes identified by mRNA expression profiling, we detected 59 overlapped genes, such as STEAP4 [P_TWAS = 0.0270, FC (fold change)_mRNA = 7.03], RABEP1 (P_TWAS = 0.010, FC_mRNA = 2.22), and MORC3 (P_TWAS = 0.0053, FC_mRNA = 2.92). The GO analysis of TWAS-identified genes discovered 53 GO terms for ON. Further comparing the GO results of TWAS and mRNA expression profiling identified four overlapped GO terms, including cysteine-type endopeptidase activity (P_TWAS = 0.0006, P_mRNA = 0.0227), extracellular space (P_TWAS = 0.0342, P_mRNA = 0.0012), protein binding (P_TWAS = 0.0112, P_mRNA = 0.0106), and ATP binding (P_TWAS = 0.0464, P_mRNA = 0.0033).

Conclusion

Several ONFH-associated genes and GO terms were identified by integrating TWAS and mRNA expression profiling. It provides novel clues to reveal the pathogenesis of ONFH.

Bioinformatics analysis and identification of genes and molecular pathways in steroid-induced osteonecrosis of the femoral head

Background

Steroid-induced osteonecrosis of the femoral head (ONFH) is a common hip joint disease and is difficult to be diagnosed early. At present, the pathogenesis of steroid-induced ONFH remains unclear, and recognized and effective diagnostic biomarkers are deficient. The present study aimed to identify potentially important genes and signaling pathways involved in steroid-induced ONFH and investigate their molecular mechanisms.

Methods

Microarray data sets GSE123568 (peripheral blood) and GSE74089 (cartilage) were obtained from the Gene Expression Omnibus database, including 34 ONFH samples and 14 control samples. Morpheus software and Venn diagram were used to identify DEGs and co-expressed DEGs, respectively. Besides, we conducted Kyoto Encyclopedia of Genome (KEGG) and gene ontology (GO) pathway enrichment analysis. We construct a protein-protein interaction (PPI) network through GEO2R and used cytoHubba to divide the PPI network into multiple sub-networks. Additionally, quantitative real-time polymerase chain reaction (qRT-PCR) was performed to verify the bioinformatics analysis results.

Results

A total of 118 intersecting DEGs were obtained between the peripheral blood and cartilage samples, including 40 upregulated genes and 78 downregulated genes. Then, GO and KEGG pathway enrichment analysis revealed that upregulated DEGs focused on the signaling pathways related to staphylococcus aureus infection, leishmaniasis, antigen processing, and presentation, as well as asthma and graft-versus-host disease. Downregulated genes were concentrated in the FoxO signaling pathway, AMPK signaling pathway, signaling pathway regulating stem cell pluripotency, and mTOR signaling pathway. Some hub genes with high interactions such as CXCR1, FPR1, MAPK1, FOXO3, FPR2, CXCR2, and TYROBP were identified in the PPI network. The results of qRT-PCR demonstrated that CXCR1, FPR1, and TYROBP were upregulated while MAPK1 was downregulated in peripheral blood of steroid-induced ONFH patients. This was consistent with the bioinformatics analysis.

Conclusions

The present study would provide novel insight into the genes and associated pathways involved in steroid-induced ONFH. CXCR1, FPR1, TYROBP, and MAPK1 may be used as potential drug targets and biomarkers for the diagnosis and prognosis of steroid-induced 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.

The potential role of lncRNAs in osteoporosis

Osteoporosis is a common bone disease characterized by low bone mass and deterioration of bone microstructure, which predisposes to higher risks of bone fragility and bone fracture. Long non-coding RNAs (lncRNAs) are a class of RNAs with a length of > 200 nucleotides without protein-coding function, which control the expression of genes and affect multiple biological processes. Accumulating evidence suggests that lncRNAs are widely involved in the molecular mechanisms of osteoporosis. This review aims to summarize the function and underlying mechanism of lncRNAs involved in the development of osteoporosis, and how it contributes to osteoblast and osteoclast function. This knowledge will shed new light on the modulation and potential treatment of osteoporosis.

Targeting DKK1 prevents development of alcohol-induced osteonecrosis of the femoral head in rats

Osteonecrosis of the femoral head (ONFH) is a devastating bone disease characterized by avascular or aseptic necrosis of the femoral head, and alcohol consumption is reported one of the leading risks to this disease. Previous studies have linked Dickkopf-1 (DKK1) to the occurrence of ONFH, but the role of DKK1 in alcohol-induced ONFH (AONFH) has not been fully discussed. In this study, we found that the expression level of DKK1 was dramatically increased in serum and bone samples from AONFH patients, experimental AONFH rats, and cultured bone marrow mesenchymal stem cells (BMMSCs) with ethanol stimulation. Elevated DKK1 inhibited Wnt/β-catenin signaling in vivo and in vitro, while knockdown of DKK1 enhanced the nuclear translocation of β-catenin and promoted osteogenesis and inhibited adipogenesis in the BMMSC cell line C3H10T1/2. Local injection of DKK1 knockout lentivirus into the femoral head of rats alleviated the progression of AONFH, with activated Wnt/β-catenin signaling, increased bone formation, reduced number of empty adipose lacunae and restored blood supply. In conclusion, our findings confirmed the important role of DKK1 and canonical Wnt/β-catenin pathway in AONFH. We propose that DKK1 may be a prognostic marker of AONFH and targeting DKK1 to activate the canonical Wnt/β-catenin pathway and restore osteogenic potential could be a promising therapeutic strategy to prevent AONFH.

ARCO Consensus on the Pathogenesis of Non-traumatic Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) is a devastating disease frequently leading to femoral head collapse and hip arthritis. Specifically, non-traumatic ONFH primarily affects young and middle-aged adults. Although compromised local circulation of the femoral head seems to be pathognomonic for the disease, the pathogenesis is perplexing and continues to be an area of scrutiny and research. Comprehension of the pathogenesis is of crucial importance for developing and guiding treatments for the disease. Therefore, we provide an up-to-date consensus on the pathogenesis of non-traumatic 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.

Inflammation, Bone Healing and Osteonecrosis: From Bedside to Bench

Osteonecrosis of the epiphyseal and metaphyseal regions of major weight-bearing bones of the extremities is a condition that is associated with local death of bone cells and marrow in the afflicted compartment. Chronic inflammation is a prominent feature of osteonecrosis. If the persistent inflammation is not resolved, this process will result in progressive collapse and subsequent degenerative arthritis. In the pre-collapse stage of osteonecrosis, attempt at joint preservation rather than joint replacement in this younger population with osteonecrosis is a major clinical objective. In this regard, core decompression, with/without local injection of bone marrow aspirate concentrate (BMAC), is an accepted and evidence-based method to help arrest the progression and improve the outcome of early-stage osteonecrosis. However, some patients do not respond favorably to this treatment. Thus, it is prudent to consider strategies to mitigate chronic inflammation concurrent with addressing the deficiencies in osteogenesis and vasculogenesis in order to save the affected joint. Interestingly, the processes of inflammation, osteonecrosis, and bone healing are highly inter-related. Therefore, modulating the biological processes and crosstalk among cells of the innate immune system, the mesenchymal stem cell-osteoblast lineage and others are important to providing the local microenvironment for resolution of inflammation and subsequent repair. This review summarizes the clinical and biologic principles associated with osteonecrosis and provides potential cutting-end strategies for modulating chronic inflammation and facilitating osteogenesis and vasculogenesis using local interventions. Although these studies are still in the preclinical stages, it is hoped that safe, efficacious, and cost-effective interventions will be developed to save the host’s natural joint.

Changes of lipid and bone metabolism in broilers with spontaneous femoral head necrosis

Blood biochemistry and bone metabolism were evaluated to investigate the etiology and mechanism of spontaneous femoral head necrosis (FHN) in broilers. According to the femoral head score of the fourth, fifth, and sixth week old FHN-affected broilers, they were divided into 3 groups, namely Normal group, femoral head separation group, and femoral head separation with growth plate lacerations group, and then carried out a comparative study. The results showed that the liver function (alanine aminotransferase and aspartate aminotransferase) and lipid metabolism (high-density lipoprotein and triglyceride) levels of broilers with spontaneous FHN were significant changed compared with the normal group. At the same time, accumulation of lipid droplets appeared in the liver, which illustrated that the occurrence of FHN may be related to lipid metabolism disorders. Tibia and femur parameters showed significant changes in bone mineral density and bone strength. The distribution of chondrocytes in the articular cartilage of broilers with FHN was irregular and vacuoles appeared, which indicated that cartilage homeostasis was destroyed. TUNEL staining showed that the apoptosis rate of articular chondrocytes in broilers with FHN in 6-week-old was significantly higher than that of normal broilers. Meanwhile, the bone markers (bone glaprotein and bone-specific alkaline phosphatase) changed significantly, indicating that the articular chondrocyte apoptosis and bone metabolism disorder may occur in FHN-affected birds. Therefore, FHN in broilers may be caused by dyslipidemia and abnormal bone metabolism.

An animal model of early-stage femoral head osteonecrosis induced by cryo-insult in small tailed Han sheep

Purpose

This study investigated the ability of liquid nitrogen cryo-insults to induce early-stage osteonecrosis of the femoral head (ONFH) in small tail Han sheep.

Methods

16 animals were subjected to unilateral cryo-insult using cryogen equipment with a cryo-insult probe, followed 1, 3, and 6 months later by X-ray, CT scanning, micro-CT scanning, and histological evaluation.

Results

X-ray evaluation of operative femoral heads (Op-FHs) at each time point showed low density areas under the cartilage surface that paralleled sclerosis belts, and CT scans showed sclerosis and cyst areas in Op-FHs. Micro-CT analysis showed that the ratio of bone to total volume and mean trabecular thickness of regions of interest (ROIs) were lower in Op-FHs than in normal femoral heads (No-FHs) at each time point (n = 4, p < 0.05). Histological evaluation at 1 month showed that necrotic changes were dominant as evidenced by moderate empty lacunae, decreases in the number of hematopoietic cells, and moderate increases in the number of fibroblasts. At 3 and 6 months, fractured trabeculae, fibroblasts, and new blood capillaries were increased, indicating an absorption and repair process. Bone volume fraction of ROIs of Op-FHs was lower than in No-FHs at each time point (n = 4, p < 0.05) in histological evaluation. At 6 months, the maximum load of No-FHs was higher than Op-FHs (n = 4, p < 0.05).

Conclusion

These findings indicate that early-stage ONFH can be induced in small tail Han sheep using cryogenic equipment.

The translational potential of this article

This animal model may be helpful in developing new treatment modalities for human ONFH.

Risk factors for osteonecrosis of the femoral head in brain tumor patients receiving corticosteroid after surgery

Purpose

Non-traumatic osteonecrosis of the femoral head (ONFH) is a plausible complication in brain tumor patients. Frequent use of corticosteroid therapy, chemotherapy, and oxidative stress for managing brain tumors may be associated with the development of ONFH. However, there is little knowledge on the prevalence and risk factors of ONFH from brain tumor. This study aimed to investigate the prevalence and risk factors of ONFH in patients with primary brain tumors.

Methods

This retrospective cohort study included data from consecutive patients between December 2005 and August 2016 from a tertiary university hospital in South Korea. A total of 73 cases of ONFH were identified among 10,674 primary brain tumor patients. After excluding subjects (25 out of 73) with missing data, history of alcohol consumption or smoking, history of femoral bone trauma or surgery, comorbidities such as systemic lupus erythematosus (SLE), sickle cell disease, cancer patients other than brain tumor, and previous diagnosis of contralateral ONFH, we performed a 1:2 propensity score-matched, case–control study (ONFH group, 48; control group, 96). Risk factors of ONFH in primary brain tumor were evaluated by univariate and multivariate logistic regression analyses.

Results

The prevalence of ONFH in patients with surgical resection of primary brain tumor was 683.9 per 100,000 persons (73 of 10,674). In this cohort, 55 of 74 patients (74.3%) underwent THA for ONFH treatment. We found that diabetes was an independent factor associated with an increased risk of ONFH in primary brain tumor patients (OR = 7.201, 95% CI, 1.349–38.453, p = 0.021). There was a significant difference in univariate analysis, including panhypopituitarism (OR = 4.394, 95% CI, 1.794–11.008, p = 0.002), supratentorial location of brain tumor (OR = 2.616, 95% CI, 1.245–5.499, p = 0.011), and chemotherapy (OR = 2.867, 95% CI, 1.018–8.069, p = 0.046).

Conclusions

This study demonstrated that the prevalence of ONFH after surgical resection of primary brain tumor was 0.68%. Diabetes was an independent risk factor for developing ONFH, whereas corticosteroid dose was not. Routine screening for brain tumor-associated ONFH is not recommended; however, a high index of clinical suspicion in these patients at risk may allow for early intervention and preservation of the joints.

Results of advanced core decompression in patients with osteonecrosis of the femoral head depending on age and sex-a prospective cohort study

Background

Core decompression is a common surgical technique to treat osteonecrosis of the femoral head. The aim of this study is to evaluate the effect of the parameters “age” and “sex” on the outcome of this type of treatment.

Methods

A prospective cohort study was performed. Eighty-six osteonecrotic hips with a mean follow-up of 32.5 months (± 24.8) after advanced core decompression were analysed regarding age- and sex-dependent treatment failure. Additionally, the modified Harris Hip Score and Numeric Rating Scale were compared regarding the parameters age and sex.

Results

The mean hip survival of the male participants was 51.3 months (39.4% treatment failure), whereas females presented a longer, thus not significant, mean survival of 61.4 months (30% therapy failure; p = 0.48). The further evaluation revealed significantly better survival in the patients aged < 40 years (mean survival 66.09 months, 16% treatment failure) in comparison to those aged ≥ 40 years (mean survival 50.14 months, 46% therapy failure; p = 0.03). The modified Harris Hip Score and Numeric Rating Scale results of patients whose treatment did not fail during the study period were similar, irrespective of the patient’s sex or age.

Conclusions

The study shows that the number of therapy failures is significantly higher in older patients, with 40 years of age marking the borderline. Patients’ sex does not seem to affect the outcome of treatment, and postoperative clinical scores appear to be identical with individuals not affected by therapy failure. Since age and sex are unalterable parameters, the study helps to provide valuable predictions regarding the chances of long-term hip survival after treatment of osteonecrosis.