Current concepts on osteonecrosis of the femoral head

Advancements in 3D printing technologies for personalized treatment of osteonecrosis of the femoral head

Three-dimensional (3D) printing technology has shown significant promise in the medical field, particularly in orthopedics, prosthetics, tissue engineering, and pharmaceutical preparations. This review focuses on the innovative application of 3D printing in addressing the challenges of osteonecrosis of the femoral head (ONFH). Unlike traditional hip replacement surgery, which is often suboptimal for younger patients, 3D printing offers precise localization of necrotic areas and the ability to create personalized implants. By integrating advanced biomaterials, this technology offers a promising strategy approach for early hip-preserving treatments. Additionally, 3D-printed bone tissue engineering scaffolds can mimic the natural bone environment, promoting bone regeneration and vascularization. In the future, the potential of 3D printing extends to combining with artificial intelligence for optimizing treatment plans, developing materials with enhanced bioactivity and compatibility, and translating these innovations from the laboratory to clinical practice. This review demonstrates how 3D printing technology uniquely addresses critical challenges in ONFH treatment, including insufficient vascularization, poor mechanical stability, and limited long-term success of conventional therapies. By introducing gradient porous scaffolds, bioactive material coatings, and AI-assisted design, this work outlines novel strategies to improve bone regeneration and personalized hip-preserving interventions. These advancements not only enhance treatment efficacy but also pave the way for translating laboratory findings into clinical applications.

Automated detection of early-stage osteonecrosis of the femoral head in adult using YOLOv10: Multi-institutional validation

OBJECTIVES

To develop a deep learning model based on the You Only Look Once version 10 (YOLOv10) for detecting early-stage ONFH in adult using radiographs.

METHODS

A retrospective database study enrolled patients with ONFH classified as the stage I-II by the Association Research Circulation Osseous (ARCO) staging system based on MRI, and with Kellgren-Lawrence (KL) grade ≤ 1, as the positive group. In negative group, femoral head exhibited normal or KL grade 1 changes. The model was developed by using internal dataset from one institution between November 2008 and June 2024, with patients were divided into training and internal validation sets in an 8:2 ratio. External test sets were enrolled from two independent institutions between December 2021 and June 2024. Intersection over Union (IoU) was utilized to assess accuracy of bounding box placement and inter-observer consistency. Classification performance was evaluated using the area under the curve (AUC).

RESULTS

A total of 2321 patients (mean age, 51 years ± 14 [SD]; 961 female) with 3970 unilateral hip joint radiographs were evaluated. The model achieved accuracies of 0.91, and 0.89 with IoU scores of 0.95 and 0.96 in two external test sets. The model outperformed the radiologists: for the external test set 1, AUC was 0.93 (95 % CI 0.88-0.97) versus an average AUC of 0.83 among radiologists (range: 0.78-0.88); for the external test set 2, AUC was 0.94 (95 % CI 0.90-0.98) versus an average AUC of 0.79 (range: 0.74-0.85).

CONCLUSIONS

The YOLOv10 model excelled in detecting early-stage ONFH in adult using radiographs, and outperforming radiologists with varying experience.

A nomogram for predicting contralateral femoral head collapse after unilateral replacement of bilateral femoral head necrosis

This study aimed to develop and validate a nomogram, which can effectively predict the risk of contralateral asymptomatic femoral head collapse in patients with bilateral osteonecrosis of the femoral head (ONFH), undergoing unilateral total hip arthroplasty (THA). We retrospectively analyzed the clinical data of patients who underwent unilateral THA for bilateral non-traumatic ONFH in our center from 2015 to 2018. A total of 103 patients participated in at least 5 years of follow-up. The patients were randomly divided into a training set (70%) and a validation set (30%). Univariate and multivariate Cox analyses were used to determine the independent risk factors for contralateral femoral head collapse. Based on these factors, a predictive nomogram model for 3, 4, and 5 years after THA was developed, and the model was evaluated using receiver operating characteristic (ROC) curve analysis, area under the curve (AUC), decision curve analysis (DCA), and calibration curves. Among the103 patients, 64 patients (62.1%) experienced contralateral femoral head collapse after surgery. Independent risk factors included Japanese investigation committee (JIC) types C1 and C2, lower limb length difference, CE angle, and Harris hip score (HHS) one month after the primary THA. The AUC, calibration curves, and DCA for the predictive model at 3, 4, and 5 years demonstrated good performance of the nomogram. The predictive nomogram model shows good accuracy and clinical utility. Using this tool, clinicians can accurately judge the collapse of the contralateral asymptomatic femoral head after unilateral THA in patients with bilateral ONFH, and they can formulate individualized treatment plans.

Osteonecrosis: A disabling disease not to be ignored in asthma and atopic conditions

Osteonecrosis, also referred to as avascular necrosis, is a disease characterized by necrosis or death of a bone secondary to impairment in blood supply. The condition affects the epiphyseal ends of the bones such as the femur and the humerus, but it can also involve the metacarpal and metatarsal bones, the patella, the knee, the vertebrae, and the jaw. A plethora of inflammatory, autoimmune, hematological, thrombotic, and vascular diseases can lead to osteonecrosis. Corticosteroids are intimately linked to the development of osteonecrosis. The frequent use of systemic corticosteroids in patients with asthma, eczema, nasal polyposis, sinusitis, urticaria and angioedema, or anaphylaxis makes this disease of great relevance to the practicing allergist and pulmonologist. Untreated, bone necrosis leads to frustrated bone remodeling and angiogenesis, leading to subchondral fractures and collapse of the articular heads of the bones, and culminating in debilitating osteoarthritis, often requiring arthroplasty. Recent studies have shed light on the molecular mechanisms underlying osteonecrosis and on the role of glucocorticoids. The gold standard test in patients suspected of having the disease is magnetic resonance imaging scanning, with plain radiographs having a lower sensitivity and specificity. Early diagnosis and intervention are essential. The allergist should avoid the frequent use of glucocorticoids and consider early introduction of steroid-sparing alternatives for asthma or sinusitis. Smoking and alcohol ingestion need to be addressed, and the management of glucocorticoid-induced osteoporosis may be helpful. It is essential for allergists to familiarize themselves with the disease and its diagnosis and to consider early referral to an orthopedic surgeon for surgical intervention.

Location or size? A finite element analysis study of necrotic lesion impact on femoral head collapse

BACKGROUND

The location and size of necrotic lesions are important factors for collapse, The preserved angles (PAs) are divided into anterior preserved angle (APA) and lateral preserved angle (LPA), which could accurately measure the location of necrosis lesion. We used them to evaluate the effect of the location and size of necrotic lesions on collapse by finite element analysis, to offer a framework for evaluating the prognosis of osteonecrosis of the femoral head (ONFH) in clinical settings.

METHODS

3 left hip models were constructed based on CT data. Within each hip model, three necrosis lesion models were modeled, with necrotic tissue volumes of 30%, 50%, and 70% repectively. The ONFH models with LPA of 45.5°, 50.5°, 55.5°, 60.5°, 65.5°, 70.5°, and 75.5° when APA was 60.5°, and ONFH models with APAs of 45.5°, 50.5°, 55.5°, 60.5°, 65.5°, 70.5°, and 75.5° when LPA was 60.5° were Constructed. The maximum von Mises stess of the femoral head and necrotic lesion, as well as the femoral head displacement, were calculated to evaluate the biomechanical effects of these models.

RESULTS

(1) In models with the same necrotic volume, when APA was 60.5°, the indexes of the LPA < 60.5° models were significantly higher than those of the LPA ≥ 60.5° models (P < 0.05); the differences of the indexes among the LPA ≥ 60.5° models were not statistically significant (P > 0.05). (2) When LPA was 60.5°, the indexes of models with APA < 60.5 ° and APA ≥ 60.5 ° show the same trend as the former. (3) In the models with the same PAs, there was no statistically significant difference in the indexes (P > 0.05).

CONCLUSION

The location of the necrotic lesion exerts a greater impact on femoral head collapse compared with the size of the lesion. The location of the necrosis may deserve more consideration when assessing the risk of collapse in patients with early onset ONFH.

Avascular necrosis or rapid destruction of the hip following hip intra-articular corticosteroid injections: a systematic review

PURPOSE

This study aimed to systematically review the literature to identify the incidence of avascular necrosis (AVN) following hip intra-articular corticosteroid injections (IACSIs) as well as to elucidate risk factors that may predispose patients to AVN following IACSI.

METHODS

The MEDLINE, Embase, PubMed, and Web of Science databases were systematically searched through inception to July 21, 2024, in accordance with the PRISMA statement with data extracted for descriptive analysis. The inclusion criteria were hip IACSI and AVN of the femoral head. AVN identified solely prior to IACSI, animal studies, in vitro studies, and studies on paediatric populations were excluded.

RESULTS

A total of 3,652 studies were identified and screened resulting in a total of 14 studies that met the inclusion criteria. Seven were case reports, four were retrospective case-series, and three were retrospective cohort studies. The incidence of femoral head AVN following IACSI ranged from 0.6 to 20.4%. Kelly et al. reported that patient-related factors associated with increased rate of AVN included elevated BMI (p = 0.025), history of cancer therapy (p = 0.012), low serum Vitamin D (p = 0.030), and multiple injections (p = 0.004).

CONCLUSION

In the present literature, the incidence of AVN after hip IACSI ranges from 0.6 to 20.4% with mean follow-up times ranging from 5.4 to 25.3 months. Further randomized controlled trials are necessary to elucidate if there is a causative relationship between hip IACSI and AVN.

Bioengineering strategies targeting angiogenesis: Innovative solutions for osteonecrosis of the femoral head

Osteonecrosis of the femoral head (ONFH) is a prevalent orthopedic disorder characterized primarily by compromised blood supply. This vascular deficit results in cell apoptosis, trabecular bone loss, and structural collapse of the femoral head at late stage, significantly impairing joint function. While MRI is a highly effective tool for diagnosing ONFH in its early stages, challenges remain due to the limited availability and high cost of MRI, as well as the absence of routine MRI screening in asymptomatic patients. . In addition, current therapeutic strategies predominantly only relieve symptoms while disease-modifying ONFH drugs are still under investigation/development. Considering that blood supply of the femoral head plays a key role in the pathology of ONFH, angiogenic therapies have been put forward as promising treatment options. Emerging bioengineering interventions targeting angiogenesis hold promising potential for ONFH treatment. In this review, we introduce the advances in research into the pathology of ONFH and summarize novel bioengineering interventions targeting angiogenesis. This review sheds light upon new directions for future research into ONFH.

Core Decompression With Bone Marrow Aspirate Concentrate for Avascular Necrosis of the Femoral Head

INTRODUCTION

Avascular necrosis (AVN) of the femoral head is a complex and debilitating condition that predominantly affects a relatively young population. Core decompression of the femoral head is the primary surgical option for joint preservation, most commonly used in the early stages. However, clinical and radiological outcomes are variable in the literature. Biological therapies, such as bone marrow aspirate concentrate (BMAC), have also been used as adjuvants to complement this procedure. This study aims to evaluate the outcomes of this surgical intervention.

METHODS

From 2012 to 2022, we conducted a retrospective study at a small Portuguese National Health Service hospital of all patients who underwent core decompression combined with the use of BMAC. Clinical data were reviewed, and telephone interviews were conducted, with functional scores completed and radiological criteria assessed. The primary outcome was preservation of the native hip at two years postoperatively.

RESULTS

The series included 18 patients, totaling 24 affected hips. The average survival time after core decompression with BMAC was 14 months. The outcome was favorable in six (25%) hips, while 18 (75%) hips required a salvage arthroplasty. Patients with smaller preoperative lesions had more favorable outcomes than those with larger lesions.

CONCLUSION

The results of this study seem to confirm the importance of lesion size as a prognostic factor in the treatment of AVN lesions. Early stages alone do not guarantee surgical success.

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.

Research on Lipidomic Profiling and Biomarker Identification for Osteonecrosis of the Femoral Head

Objectives: Abnormal lipid metabolism is increasingly recognized as a contributing factor to the development of osteonecrosis of the femoral head (ONFH). This study aimed to explore the lipidomic profiles of ONFH patients, focusing on distinguishing between traumatic ONFH (TONFH) and non-traumatic ONFH (NONFH) subtypes and identifying potential biomarkers for diagnosis and understanding pathogenesis. Methods: Plasma samples were collected from 92 ONFH patients (divided into TONFH and NONFH subtypes) and 33 healthy normal control (NC) participants. Lipidomic profiling was performed using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Data analysis incorporated a machine learning-based feature selection method, least absolute shrinkage and selection operator (LASSO) regression, to identify significant lipid biomarkers. Results: Distinct lipidomic signatures were observed in both TONFH and NONFH groups compared to the NC group. LASSO regression identified 11 common lipid biomarkers that signify shared metabolic disruptions in both ONFH subtypes, several of which exhibited strong diagnostic performance with areas under the curve (AUCs) > 0.7. Additionally, subtype-specific lipid markers unique to TONFH and NONFH were identified, providing insights into the differential pathophysiological mechanisms underlying these subtypes. Conclusions: This study highlights the importance of lipidomic profiling in understanding ONFH-associated metabolic disorders and demonstrates the utility of machine learning approaches, such as LASSO regression, in high-dimensional data analysis. These findings not only improve disease characterization but also facilitate the discovery of diagnostic and mechanistic biomarkers, paving the way for more personalized therapeutic strategies in ONFH.

Human umbilical cord mesenchymal stem cells protect MC3T3-E1 osteoblasts from dexamethasone-induced apoptosis via induction of the Nrf2-ARE signaling pathway

Objective

To investigate the protective effect human umbilical cord mesenchymal stem cells (hUC-MSCs) have on Dexamethasone (Dex)-induced apoptosis in osteogenesis via the Nrf2-ARE signaling pathway.

Methods

Glucocorticoid-induced osteonecrosis of the femoral head (GC-ONFH) was developed in rats through the administration of lipopolysaccharide and methylprednisolone. The incidence of femoral head necrosis, cavity notch, apoptosis of osteoblasts, and bone density were observed by HE staining, TUNEL staining, and Micro-CT. HUC-MSCs were co-cultured with mouse pre-osteoblast MC3T3-E1. The survival rate of osteoblasts was determined by CCK8, and apoptosis and ROS levels of osteoblasts were determined by flow cytometer. The viability of antioxidant enzymes SOD, GSH-Px, and CAT was analyzed by biochemistry. Nrf2 expression levels and those of its downstream proteins and apoptosis-related proteins were analyzed by Western blotting.

Results

In rats, hUC-MSCs can reduce the rates of empty bone lacuna and osteoblast apoptosis that are induced by glucocorticoids (GCs), while reducing the incidence of GC-ONFH. hUC-MSCs can significantly improve the survival rate and antioxidant SOD, GSH-Px, and CAT activity of MC3T3-E1 cells caused by Dex, and inhibit apoptosis and oxidative stress levels. In addition, hUC-MSCs can up-regulate the expression of osteoblast antioxidant protein Nrf2 and its downstream protein HO-1, NQO-1, GCLC, GCLM, and apoptosis-related protein bcl-2, while also down-regulating the expression of apoptosis-related protein bax, cleaved caspase-3, cleaved caspase-9, and cytochrome C in MC3T3-E1 cells. hUC-MSCs improve the ability of MC3T3-E1 cells to mineralize to osteogenesis. However, the promoting effects of hUC-MSCs were abolished following the blocking of the Nrf2-ARE signaling pathway for osteoblasts.

Conclusion

The results reveal that hUC-MSCs can reduce Dex-induced apoptosis in osteoblasts via the Nrf2-ARE signaling pathway.

Comparison of epoprostenol and viscum album efficiencies in the treatment of avascular necrosis of the femoral head: An experimental animal study

BACKGROUND

The aim of our study is to compare the efficacy of epoprostenol and viscum album in the treatment of femoral head avascular necrosis with an experimental study. Our hypothesis is that viscum album, which has similar properties to epoprostenol on the vascular system, is as effective as epoprostenol in the treatment of avascular necrosis.

METHODS

Avascular necrosis was created on the femoral heads of 45 New Zealand type rabbits by surgical vascular deprivation method. The rabbits were divided into 3 groups. Group 1 was designed as a control group, in group 2 Ilomedin (epoprostenol analogue) was administrated to subjects and in group 3, Helixor (viscum album extract) was administrated. At the end of the study, there were nine subjects in each group. Osteocyte necrosis, bone marrow necrosis, new bone formation and cartilage degeneration were evaluated microscopically. The extent of bone necrosis and repair and involvement of epiphysis, the bone marrow cellularity ratio and trabecular bone volume were investigated.

RESULTS

Subchondral necrosis was seen in more animals in the control group (p=0.03). Osteoblastic and osteoclastic activity were more prominent in the Ilomedin group (p=0.25 and 0.07, respectively). It was seen that the cartilages of the subjects in the Helixor and Ilomedin groups were less damaged. In the Ilomedin group, more animals were seen in the chronic phase of the repair process than in the other groups (p=0.07). Bone marrow cellularity was higher in treatment groups (22% and 20,6% for Ilomedin and Helixor, respectively, p=0,04). Trabecular volume was found to be increased in damaged femoral heads in the treatment groups, the highest increased observed in the Helixor group (p=0.01).

CONCLUSION

Viscum album seems to be effective in decreasing the extention of necrosis and protecting the articular cartilage, and epoprostenol in increasing repair and regeneration.

Mechanism of action of Salvia miltiorrhiza on avascular necrosis of the femoral head determined by integrated network pharmacology and molecular dynamics simulation

Avascular necrosis of the femoral head (ANFH) is a progressive, multifactorial, and challenging clinical condition that often leads to hip dysfunction and deterioration. The pathogenesis of ANFH is complex, and there is no foolproof treatment strategy. Although some pharmacologic and surgical treatments have been shown to improve ANFH, the associated side effects and poor prognosis are of concern. Therefore, there is an urgent need to explore therapeutic interventions with superior efficacy and safety to improve the quality of life of patients with ANFH. Salvia miltiorrhiza (SM), a traditional Chinese medicine with a long history, is widely used for the treatment of cardiovascular and musculoskeletal diseases due to its multiple pharmacological activities. However, the molecular mechanism of SM for the treatment of ANFH is still unclear. Therefore, this study aimed to explore the potential targets and mechanisms of SM for the treatment of ANFH using network pharmacology and molecular modeling techniques. By searching multiple databases, we screened 52 compounds and 42 common targets involved in ANFH therapy and identified dan-shexinkum d, cryptotanshinone, tanshinone iia, and dihydrotanshinlactone as key compounds. Based on the protein-protein interaction (PPI) network, TP53, AKT1, EGFR, STAT3, BCL2, IL6, and TNF were identified as core targets. Subsequent enrichment analysis revealed that these targets were mainly enriched in the AGE-RAGE, IL-17, and TNF pathways, which were mainly associated with inflammatory responses, apoptosis, and oxidative stress. In addition, molecular docking and 100 nanoseconds molecular dynamics (MD) simulations showed that the bioactive compounds of SM had excellent affinity and binding strength to the core targets. Among them, dan-shexinkum d possessed the lowest binding free energy (-215.874 kcal/mol and - 140.277 kcal/mol, respectively) for AKT1 and EGFR. These results demonstrated the multi-component, multi-target, and multi-pathway intervention mechanism of SM in the treatment of ANFH, which provided theoretical basis and clues for further experimental validation and development of anti-ANFH drugs.

Angiogenesis of Avascular Necrosis of the Femoral Head: A Classic Treatment Strategy

Avascular necrosis of the femoral head (ANFH) is a type of osteonecrosis due to the cessation of blood supply, characterized by persistent local pain and collapse of the joint. The etiology of ANFH is multifaceted, and while its precise pathogenesis remains elusive, it is currently widely believed that the femoral head is highly dependent on the vascular system. A large number of studies have shown that vascular injury is the initial factor in the onset of ANFH. In this review, we briefly introduced the process of angiogenesis and the blood supply to the femoral head, with a focus on summarizing the existing research on promoting angiogenesis for the treatment of ANFH. We conclude that providing alternative pathways through angiogenesis to resolve the problem of the obstructed free flow of the blood is an important means of treating ANFH. Moreover, we also looked forward to the mechanism of endothelial metabolism, which has not yet been studied in femoral head necrosis models, providing potential strategies for more effective use of angiogenesis for the treatment of femoral head necrosis.

Avascular necrosis of the femoral head: which MRI parameters or findings are more decisive for determining the prognosis?

BACKGROUND

Predicting the development of collapse in patients with avascular necrosis of the femoral head (ANFH) is critical in determining prognosis and management.

OBJECTIVE

We aimed to evaluate whether MRI findings and parameters based on the Association Research Circulation Osseous (ARCO), Japanese Investigation Committee (JIC), modified Kerboul, and Mitchell classifications can predict prognosis in patients with early-stage ANFH at initial diagnosis.

METHODS

This study comprises a retrospective analysis of early-stage ANFH patients without femoral head collapse. Hips with ANFH were divided into two groups based on whether they developed collapse during at least 1 year of follow-up or not. MRI findings were assessed by two radiologists and compared between the groups. Interobserver reliability was also evaluated.

RESULTS

Patients who developed collapse had higher measurements in the percentage of midcoronal area, midsagittal area, maximum coronal area, and total necrotic area (p = 0.001, p = 0.001, p < 0.001, p = 0.003, respectively). Although all AUC values were close to each other, the percentage of maximum coronal area showed the highest AUC value (0.857; 95% CI 0.714-1.000; sensitivity 85.7%, specificity 80%) in ROC curve analysis. Interobserver reliability was best for the JIC and worst for the modified Kerboul classification (Kappa values: 0.890 and 0.492, respectively). No statistically significant difference was found among etiological factors, bone marrow edema, cyst-like changes, synovial effusion, and collapse development (p > 0.05). The double-line sign was statistically significantly more frequent in hips without collapse (p = 0.025).

CONCLUSION

The risk of collapse development is higher with a greater volume of necrosis in the femoral head and when the osteonecrosis is located more laterally.

Identification and validation of endoplasmic reticulum stress-related genes in patients with steroid-induced osteonecrosis of the femoral head

Steroid-induced osteonecrosis of the femoral head (SONFH) is a debilitating condition caused by long-term corticosteroid use, leading to impaired blood flow and bone cell death. The disruption of cellular processes and promotion of apoptosis by endoplasmic reticulum stress (ERS) is implicated in the pathogenesis of SONFH. We identified ERS-associated genes in SONFH and investigated their potential as therapeutic targets. We analysed the GSE123568 GEO dataset to identify differentially expressed genes (DEGs) related to ERS in SONFH. We conducted Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses, identified hub genes by protein-protein interaction (PPI) analyses, and evaluated their functions by gene set enrichment analysis (GSEA). We constructed mRNA-miRNA networks, identified potential therapeutics, and assessed immune cell infiltration. We performed cross-validation using the GEO dataset GSE74089, qRT-PCR on clinical samples from patients with SONFH and controls, and a receiver operating characteristic (ROC) curve analysis to assess the diagnostic performance of the hub genes. We identified 195 ERS-related genes in SONFH, which were primarily involved in oxidative stress, immune responses, and metabolic pathways. The PPI network suggested CXCL8, STAT3, IL1B, TLR4, PTGS2, TLR2, CASP1, CYBB, CAT, and HOMX1 to be key hub genes, which were shown by GSEA to be involved in biological pathways related to metabolism, immune modulation, and cellular integrity. We also identified 261 microRNAs (miRNAs) as well as drugs such as dibenziodolium and N-acetyl-L-cysteine that modulated inflammatory responses in SONFH. Twenty-two immune cell subtypes showed significant correlations, such as a positive correlation between activated mast cells and Tregs, and patients with SONFH had fewer dendritic cells than controls. The hub genes CYBB and TLR4 showed significant correlations with M1 macrophages and CD8 T cells, respectively. Cross-validation and qRT-PCR confirmed the upregulation of STAT3, IL1B, TLR2, and CASP1 in patients with SONFH, validating the bioinformatics findings. An ROC curve analysis confirmed the diagnostic potential of the hub genes. The top 10 hub genes show promise as ERS-related diagnostic biomarkers for SONFH. We discovered that 261 miRNAs, including hsa-miR-23, influence these genes and identified potential therapeutics such as dibenziodolium and simvastatin. Immune profiling indicated altered immune functions in SONFH, with significant correlations among immune cell types. Validation confirmed the upregulation of STAT3, IL1B, TLR2 and CASP1, which had diagnostic potential. The findings suggest potential diagnostic markers and therapeutic targets for SONFH.

The Multiplicative Effects of Individual Risk Factors in the Development of Osteonecrosis of the Femoral Head

BACKGROUND

While individual risk factors, including chronic corticosteroid use, alcohol abuse, and smoking, are implicated in osteonecrosis of the femoral head (ONFH), the degree to which multiple risk factors increase risk is unknown. This study aimed to: (1) identify the demographic characteristics of patients who have ONFH; (2) quantify the effects of individual risk factors on ONFH development; (3) quantify the effects of combined risk factors on ONFH development; and (4) determine the prognostic implications of combined risk factors on ONFH development.

METHODS

This was a retrospective cohort study. A national insurance database was used to study a population of 2,612,383 adult patients who had a 10-year follow-up period. There were 10,233 patients identified who had a diagnosis of ONFH. We identified patients who had chronic corticosteroid use, tobacco use, and/or alcohol abuse and assessed the risk of developing ONFH over a 10-year period. Patients who had individual and multiple risk factors were grouped for comparison, and Chi-square analyses were performed.

RESULTS

Higher proportions of patients who had each individual risk factor developed ONFH compared to proportions of patients who did not have risk factors. Patients who had combined risk factors were at greater risk of developing ONFH compared to patients who had no risk factors and those who had single risk factors. Combined risk factors demonstrated multiplicative effects on the development of ONFH: tobacco-alcohol risk ratio (RR) 5.25, corticosteroid-alcohol RR 10.20, tobacco-corticosteroid RR 8.69, and corticosteroid-tobacco-alcohol RR 12.54. Patients who had combined risk factors developed ONFH at younger ages than those who had single risk factors. Kaplan-Meier curve analyses demonstrated worse 10-year hip survival in the setting of combined risk factors.

CONCLUSIONS

Combined risk factors have a multiplicative effect on the risk of developing of atraumatic ONFH. Orthopaedic surgeons may care for at-risk individuals through modulation of risk factors.

LEVEL OF EVIDENCE

Retrospective Cohort Study, Level III.

Core Decompression with Bone Marrow Aspirate Concentrate Implantation in Osteonecrosis of the Femoral Head with a Minimum of 2-year Follow-up - A Pilot Study

Introduction

Osteonecrosis of the femoral head (ONFH), resulting from impaired blood supply to the head of the femur, presents a significant challenge to clinicians due to its debilitating nature. Conservative treatment often offers insufficient pain relief and debilitating functional outcomes which necessitate alternative therapies. Bone marrow aspirate concentrate (BMAC), a potent orthobiologics and rich in mesenchymal stromal cells and growth factors, holds good promise as the minimally invasive procedure for ONFH. With the preceding research suggesting clinical and functional efficacy, we assessed the therapeutic effectiveness of BMAC in ONFH management in joint preservation.

Materials and Methods

A prospective cohort study was conducted with 20 patients suffering from ONFH who failed to respond to 6 months of conservative treatment. A uniform surgical procedure was performed by a single surgeon, involving bone marrow extraction from the anterior iliac crest and subsequent processing into an 8-10 mL of BMAC concentrate. The BMAC was then injected into the implanted into the decompressed femoral head. The post-operative protocol comprised weight-bearing mobilization, physiotherapy, and a 4-week NSAID-free regimen. Outcome measures included pain scores, hip function, knee symptoms, sports activities, patient satisfaction, and recommendation of the procedure.

Results

Of the 20 patients suffering from ONFH, primarily the left side, most of whom were at stage 2b, significant pain reduction and functional improvement were observed over 24 months. The mean pain score decreased from 9.00 to 3.55, while the hip function score increased from 46.12 to 88.60. However, some patients encountered complications such as symptom recurrence (5%), disease progression (10%), and persistent pain (5%).

Conclusion

Core decompression with BMAC implantation emerges as a promising, effective, and safe treatment for ONFH with better costeffectiveness and minimal side effects, making it a feasible treatment alternative.

Efficacy of Autologous Adult Live-Cultured Osteoblast (AALCO) Implantation in Avascular Necrosis of the Femoral Head: A Mid-Term Outcome Analysis

Introduction

Avascular Necrosis (AVN) of the femoral head, a condition characterized by the interruption of blood supply leading to bone tissue death, presents significant therapeutic challenges. Recent advancements in orthobiologics, including the use of Autologous Adult Live-Cultured Osteoblasts (AALCO), combined with core decompression, offer a novel approach for managing AVN. This study assesses the efficacy of this treatment modality in improving functional outcomes and hindering disease progression.

Materials and methods

This retrospective observational study encompassed 30 patients treated between 2020 and 2023 for idiopathic AVN of the femoral head, grades I to III, who had not responded to conservative treatment. Patients were excluded based on specific criteria including age, secondary AVN causes, and certain health conditions. The treatment involved a two-stage surgical procedure under spinal anesthesia with OSSGROW® for AALCO generation. Post-operative care emphasized early mobilization, DVT prevention, and avoidance of NSAIDs. Outcome measures were evaluated using the Visual Analog Scale (VAS) for pain, modified Harris Hip Score, and annual MRI imaging for up to 36 months.

Results

Among 26 patients (41 hips) completing the study, statistically significant improvements in pain and hip functionality were documented, alongside positive radiological signs of osteogenesis in the majority of cases. However, four instances required advancement to total hip replacement due to disease progression.

Conclusion

The combination of core decompression and AALCO implantation shows promise as an effective treatment for AVN of the femoral head, with notable improvements in functional and radiological outcomes. This study supports the potential of orthobiologic approaches in AVN treatment, warranting further investigation through comprehensive randomized controlled trials.

Graphical Abstract

Exploring the genetic association between immune cells and susceptibility to osteonecrosis using large-scale population data

Objectives

Research shows a close association between aberrant immune reactions in osteonecrotic tissues and immune cell infiltration. However, due to limitations in sample size and dataset comprehensiveness, the causal relationship between them is not fully established. This study aims to determine whether there is a causal relationship using a larger and more diverse dataset.

Methods

We conducted a comprehensive Mendelian Randomization (MR) analysis to investigate the causal relationship between immune cell characteristics and osteonecrosis. Utilizing publicly available genetic data, we explored the causal relationships between 731 immune cell features and 604 cases from the FinnGen Finnish database, as well as 257 cases from the UK Biobank database with osteonecrosis data. The inverse-variance weighted (IVW) method was used for the primary analysis, and we employed sensitivity analyses to assess the robustness of the main results. In addition, considering data from the two databases used in this study, a meta-analysis was conducted on the significant immune cells associated with osteonecrosis (FDR <0.05).

Results

our findings suggested that specific immune cell signatures, such as CD20- % lymphocytes, CD62L-monocytes, and CD33br HLA DR+ CD14-cells were associated with increased odds of osteonecrosis. In contrast, EM CD4+ activated cells and DP (CD4+ CD8+) T cells were associated with decreased odds. Notably, osteonecrosis was associated with a potential decrease in CD45 on immature MDSC cell content.

Conclusion

From a genetic perspective, we demonstrated a close association between immune cells and osteonecrosis. These findings significantly enhance our understanding of the interplay between immune cell infiltration and the risk of osteonecrosis, contributing to the potential design of therapeutic strategies from an immunological standpoint.

Identification of steroid-induced osteonecrosis of the femoral head biomarkers based on immunization and animal experiments

BACKGROUND

Steroid-induced osteonecrosis of femoral head (SONFH) is a severe health risk, and this study aims to identify immune-related biomarkers and pathways associated with the disease through bioinformatics analysis and animal experiments.

METHOD

Using SONFH-related datasets obtained from the GEO database, we performed differential expression analysis and weighted gene co-expression network analysis (WGCNA) to extract SONFH-related genes. A protein-protein interaction (PPI) network was then constructed, and core sub-network genes were identified. Immune cell infiltration and clustering analysis of SONFH samples were performed to assess differences in immune cell populations. WGCNA analysis was used to identify module genes associated with immune cells, and hub genes were identified using machine learning. Internal and external validation along with animal experiments were conducted to confirm the differential expression of hub genes and infiltration of immune cells in SONFH.

RESULTS

Differential expression analysis revealed 502 DEGs. WGCNA analysis identified a blue module closely related to SONFH, containing 1928 module genes. Intersection analysis between DEGs and blue module genes resulted in 453 intersecting genes. The PPI network and MCODE module identified 15 key targets enriched in various signaling pathways. Analysis of immune cell infiltration showed statistically significant differences in CD8 + t cells, monocytes, macrophages M2 and neutrophils between SONFH and control samples. Unsupervised clustering classified SONFH samples into two clusters (C1 and C2), which also exhibited significant differences in immune cell infiltration. The hub genes (ICAM1, NR3C1, and IKBKB) were further identified using WGCNA and machine learning analysis. Based on these hub genes, a clinical prediction model was constructed and validated internally and externally. Animal experiments confirmed the upregulation of hub genes in SONFH, with an associated increase in immune cell infiltration.

CONCLUSION

This study identified ICAM1, NR3C1, and IKBKB as potential immune-related biomarkers involved in immune cell infiltration of CD8 + t cells, monocytes, macrophages M2, neutrophils and other immune cells in the pathogenesis of SONFH. These biomarkers act through modulation of the chemokine signaling pathway, Toll-like receptor signaling pathway, and other pathways. These findings provide valuable insights into the disease mechanism of SONFH and may aid in future drug development efforts.

Deep learning approach to femoral AVN detection in digital radiography: differentiating patients and pre-collapse stages

OBJECTIVE

This study aimed to evaluate a new deep-learning model for diagnosing avascular necrosis of the femoral head (AVNFH) by analyzing pelvic anteroposterior digital radiography.

METHODS

The study sample included 1167 hips. The radiographs were independently classified into 6 stages by a radiologist using their simultaneous MRIs. After that, the radiographs were given to train and test the deep learning models of the project including SVM and ANFIS layer using the Python programming language and TensorFlow library. In the last step, the test set of hip radiographs was provided to two independent radiologists with different work experiences to compare their diagnosis performance to the deep learning models' performance using the F1 score and Mcnemar test analysis.

RESULTS

The performance of SVM for AVNFH detection (AUC = 82.88%) was slightly higher than less experienced radiologists (79.68%) and slightly lower than experienced radiologists (88.4%) without reaching significance (p-value > 0.05). Evaluation of the performance of SVM for pre-collapse AVNFH detection with an AUC of 73.58% showed significantly higher performance than less experienced radiologists (AUC = 60.70%, p-value < 0.001). On the other hand, no significant difference is noted between experienced radiologists and SVM for pre-collapse detection. ANFIS algorithm for AVNFH detection with an AUC of 86.60% showed significantly higher performance than less experienced radiologists (AUC = 79.68%, p-value = 0.04). Although reaching less performance compared to experienced radiologists statistically not significant (AUC = 88.40%, p-value = 0.20).

CONCLUSIONS

Our study has shed light on the remarkable capabilities of SVM and ANFIS as diagnostic tools for AVNFH detection in radiography. Their ability to achieve high accuracy with remarkable efficiency makes them promising candidates for early detection and intervention, ultimately contributing to improved patient outcomes.

Conservative Treatment in Avascular Necrosis of the Femoral Head: A Systematic Review

INTRODUCTION

Avascular necrosis (AVN) of the femoral head is a pressing orthopedic issue, leading to bone tissue death due to disrupted blood supply and affecting the quality of life of individuals significantly. This review focuses on conservative treatments, evaluating their efficacy as mainstay therapies. Enhanced understanding of AVN's pathophysiology and advancements in diagnostic tools have rekindled interest in non-surgical interventions, emphasizing personalized, multidisciplinary approaches for improved outcomes.

MATERIAL AND METHOD

A systematic search was conducted on PubMed, SCOPUS, and Google Scholar databases from January 2020 to August 2023, with the objective of focusing on conservative treatments for AVN of the femoral head. Eligible studies, including original research, case reports, and observational studies, were examined for relevant, well-documented patient outcomes post-conservative treatments, excluding non-English and surgically focused articles without comparative conservative data.

RESULTS

A systematic search yielded 376 records on AVN of the femoral head across multiple databases. After de-duplication and rigorous screening for relevance and quality, 11 full-text articles were ultimately included for a comprehensive qualitative synthesis, focusing on conservatively managing the condition.

CONCLUSIONS

This review evaluates the effectiveness of conservative treatments such as pharmacological interventions and physical modalities in managing AVN of the femoral head. Despite promising results in symptom alleviation and disease progression delay, variability in outcomes and methodological limitations in studies necessitate further rigorous, randomized controlled trials for a robust, patient-centric approach to optimize therapeutic outcomes in AVN management.

Three-dimensional distribution of subchondral fracture lines in osteonecrosis of the femoral head

Objective

To investigate the characteristics of three-dimensional distribution of subchondral fracture lines on the surface of the osteonecrosis femoral head, and to discuss the underlying mechanisms that contribute to its collapse.

Methods

We retrospectively analyzed computed tomography (CT) images from 75 patients (comprising a total of 77 femoral heads) diagnosed with Association Research Circulation Osseous (ARCO) stage IIIA or IIIB femoral head necrosis. The three-dimensional structures of both the femoral head and the subchondral fracture line were reconstructed and subsequently fitted into normal femoral head model. A heat map of fracture line was generated to visualize its spatial distribution across the femoral heads surface.to observe its distribution. In addition to that, the femoral head was partitioned into four zones, and the frequency of each fracture line traversing different zones was calculated and analysed.

Results

Highest and lowest density of subchondral fracture lines was demonstrated in anterolateral and posterolateral zone respectively. and most sparse in posterolateral. Furthermore, the three-dimensional heat map of fracture lines highlighted their most frequent occurrence in the anterolateral area, particularly near the junction of the femoral head and neck. One fracture line may pass through multiple areas, passage frequencies for fracture lines was observed in zones I, II, III and IV for 66 times (85.7 %), 52 times (67.5 %), 25 times (32.5 %) and 46 times (59.7 %), respectively, with a significant difference between zone I and other zones (P < 0.001).

Conclusion

Subchondral fracture line of femoral head occurs most frequently in anterolateral femoral head, suggesting that the anterolateral part may be the initial location of collapse.

Translational potential of this article

We found that the subchondral fracture line was most frequently located anterolateral to the femoral head, suggesting that this may be the site of initiation of collapse. Furthermore, we propose an innovative method for analyzing and visualizing subchondral fracture distribution in femoral head necrosis in the form of fracture line heat maps. By doing so, we provide a valuable reference for physicians, enabling them to enhance their management strategies for femoral head necrosis. Ultimately, this approach holds the promise of significantly improving the prognosis and outcomes for patients afflicted with this condition.

Pathophysiology and Evolving Treatment Options of Septic Arthritis: A Narrative Review

Pyogenic (septic) arthritis is a severe joint infection characterized by the invasion of microorganisms into the synovium, causing inflammation and joint destruction. This review article provides a comprehensive overview of pyogenic arthritis, focusing on etiology, pathogenesis, clinical manifestations, diagnosis, and management strategies. This review explores routes of microbial entry into joints, emphasizing the importance of prompt identification and treatment to prevent irreversible joint damage. Clinical manifestations, such as joint pain, swelling, and limited range of motion, are discussed, along with the challenges in differentiating pyogenic arthritis from other joint disorders. Diagnostic approaches, including joint aspiration and imaging modalities, are critically examined for accuracy in confirming diagnosis. This review also addresses the significance of early intervention through antimicrobial therapy and joint drainage, highlighting the role of multidisciplinary collaboration in optimizing patient outcomes. In summary, the present investigation underscores the complexities of pyogenic arthritis and the need for a comprehensive understanding of pathophysiology for timely and effective management to improve patient prognosis and quality of life.

Proteomic profiling of extracellular vesicles derived from human serum for the discovery of biomarkers in Avascular necrosis

BACKGROUND

Avascular necrosis (AVN) is a medical condition characterized by the destruction of bone tissue due to a diminished blood supply. When the rate of tissue destruction surpasses the rate of regeneration, effective treatment becomes challenging, leading to escalating pain, arthritis, and bone fragility as the disease advances. A timely diagnosis is imperative to prevent and initiate proactive treatment for osteonecrosis. We explored the potential of differentially expressed proteins in serum-derived extracellular vesicles (EVs) as biomarkers for AVN of the femoral head in humans. We analyzed the genetic material contained in serum-derived exosomes from patients for early diagnosis, treatment, and prognosis of avascular necrosis.

METHODS

EVs were isolated from the serum of both patients with AVN and a control group of healthy individuals. Proteomic analyses were conducted to compare the expression patterns of these proteins by proteomic analysis using LC-MS/MS.

RESULTS

Our results show that the levels of IGHV3-23, FN1, VWF, FGB, PRG4, FCGBP, and ZSWIM9 were upregulated in the EVs of patients with AVN compared with those of healthy controls. ELISA results showed that VWF and PRG4 were significantly upregulated in the patients with AVN.

CONCLUSIONS

These findings suggest that these EV proteins could serve as promising biomarkers for the early detection and diagnosis of AVN. Early diagnosis is paramount for effective treatment, and the identification of new osteonecrosis biomarkers is essential to facilitate swift diagnosis and proactive intervention. Our study provides novel insights into the identification of AVN-related biomarkers that can enhance clinical management and treatment outcomes.

Effect of Patient Age on Total Hip Arthroplasty Outcomes in Patients Who Have Osteonecrosis of the Femoral Head Compared to Patients Who Have Hip Osteoarthritis

BACKGROUND

Osteonecrosis of the femoral head (ONFH) affects both young and old patients. However, outcomes following total hip arthroplasty (THA) for these patients may vary with age. This study aimed to examine the effect of age on THA outcomes for non-traumatic ONFH patients, an area currently lacking research.

METHODS

Patients who had non-traumatic ONFH undergoing THA with at least 2 years of follow-up were identified using a database and divided into four groups by age. Then, 4 matched control groups of patients who had hip osteoarthritis (OA) were created. Multivariate logistic regression analyses were used to evaluate the rates of medical and surgical complications. Additionally, cohorts with a minimum 5-year follow-up were filtered to obtain further data on surgical outcomes. The study analyzed 85,462 non-traumatic ONFH and 80,120 hip OA patients undergoing THA.

RESULTS

Multiple medical complications in ONFH patients increased with age. Periprosthetic fracture within 2 years increased with age, while 90-day wound complications, 2-year periprosthetic joint infections, dislocations, and revisions decreased. The trends for complications continued at the 5-year follow-up. Compared to OA patients, those who had ONFH had higher risks of most complications, but this discrepancy decreased with age.

CONCLUSIONS

In ONFH patients undergoing THA, medical complications generally rise with age, while most surgical complications, including revisions, decrease. It is notable that ONFH patients experienced more complications than those who had OA, but this difference diminished with age.

Trends in avascular necrosis and related arthroplasties in hospitalized patients with systemic lupus erythematosus and rheumatoid arthritis

OBJECTIVE

Avascular necrosis (AVN) is a devastating complication often necessitating arthroplasty, particularly common in systemic lupus erythematosus (SLE). Limited research exists on arthroplasty trends since new steroid-sparing agents. We analyzed trends and characteristics associated with AVN and AVN-related arthroplasties among SLE and RA hospitalizations using two decades of data from the U.S. National Inpatient Sample (NIS).

METHODS

This cross-sectional study used NIS (2000-2019) to identify hospitalized adults with SLE and RA, with or without AVN, using ICD codes. AVN was further grouped by arthroplasty status. Primary outcomes were AVN and AVN-related arthroplasty rates and time trends in SLE and RA. Baseline sociodemographics and comorbidities were compared. Analyses used STATA and Joinpoint regression to calculate annual percent change (APC).

RESULTS

Overall, 42,728 (1.3 %) SLE and 43,600 (0.5 %) RA hospitalizations had concomitant AVN (SLE-AVN and RA-AVN). Of these, 16,724 (39 %) and 25,210 (58 %) underwent arthroplasties, respectively. RA-AVN increased (APC: 0.98*), with a decrease in arthroplasties (APC: -0.82*). In contrast, SLE-AVN initially increased with a breakpoint in 2011 (APC 2000-2011: 1.94* APC 2011-2019 -2.03), with declining arthroplasties (APC -2.03*). AVN hospitalizations consisted of individuals who were younger and of Black race; while arthroplasties were less likely in individuals of Black race or Medicaid coverage.

CONCLUSION

We report a breakpoint in rising SLE-AVN after 2011, which may relate to newer steroid-sparing therapies (i.e., belimumab). AVN-associated arthroplasties decreased in SLE and RA. Fewer AVN-associated arthroplasties were noted for Black patients and those with Medicaid, indicating potential disparities. Further research should examine treatment differences impacting AVN and arthroplasty rates.

Extracellular Vesicles: An Emerging Clinical Opportunity in Musculoskeletal Disease

Extracellular vesicles (EVs) are important mediators of cell-to-cell communication in the extracellular space. These membranous nanoparticles carry various molecules, often referred to as "cargo," which are delivered to nearby target cells. In the past decade, developments in nanotechnology have allowed for various new laboratory techniques for the increased utilization of EVs in cellular and animal studies. Such techniques have evolved for the isolation, characterization, and delivery of EVs to biological tissues. This emerging technology has immense clinical potential for both diagnostic and therapeutic applications. Various EV cargo molecules, including DNA, RNA, and proteins, can act as pathological biomarkers. Furthermore, EVs derived from certain cell sources have shown therapeutic benefit in certain pathologies. In addition to their native therapeutic benefit, EVs can be engineered to carry and selectively deliver therapeutic agents. While EVs have gained increasing interest in various pathologies, few studies have compiled their clinical potential in musculoskeletal pathologies. To bridge this gap, we present an overview of EVs, introduce current laboratory preparation techniques, and outline the most recent literature regarding the potential therapeutic applications of EVs in musculoskeletal pathologies.

Subtracting-adding strategy for necrotic lesion segmentation in osteonecrosis of the femoral head

PURPOSE

Osteonecrosis of the femoral head (ONFH) is a severe bone disease that can progressively lead to hip dysfunction. Accurately segmenting the necrotic lesion helps in diagnosing and treating ONFH. This paper aims at enhancing deep learning models for necrosis segmentation.

METHODS

Necrotic lesions of ONFH are confined to the femoral head. Considering this domain knowledge, we introduce a preprocessing procedure, termed the "subtracting-adding" strategy, which explicitly incorporates this domain knowledge into the downstream deep neural network input. This strategy first removes the voxels outside the predefined volume of interest to "subtract" irrelevant information, and then it concatenates the bone mask with raw data to "add" anatomical structure information.

RESULTS

Each of the tested off-the-shelf networks performed better with the help of the "subtracting-adding" strategy. The dice similarity coefficients increased by 10.93%, 9.23%, 9.38% and 1.60% for FCN, HRNet, SegNet and UNet, respectively. The improvements in FCN and HRNet were statistically significant.

CONCLUSIONS

The "subtracting-adding" strategy enhances the performance of general-purpose networks in necrotic lesion segmentation. This strategy is compatible with various semantic segmentation networks, alleviating the need to design task-specific models.

HIF-1α in cartilage homeostasis, apoptosis, and glycolysis in mice with steroid-induced osteonecrosis of the femoral head

With the prevalence of coronavirus disease 2019, the administration of glucocorticoids (GCs) has become more widespread. Treatment with high-dose GCs leads to a variety of problems, of which steroid-induced osteonecrosis of the femoral head (SONFH) is the most concerning. Since hypoxia-inducible factor 1α (HIF-1α) is a key factor in cartilage development and homeostasis, it may play an important role in the development of SONFH. In this study, SONFH models were established using methylprednisolone (MPS) in mouse and its proliferating chondrocytes to investigate the role of HIF-1α in cartilage differentiation, extracellular matrix (ECM) homeostasis, apoptosis and glycolysis in SONFH mice. The results showed that MPS successfully induced SONFH in vivo and vitro, and MPS-treated cartilage and chondrocytes demonstrated disturbed ECM homeostasis, significantly increased chondrocyte apoptosis rate and glycolysis level. However, compared with normal mice, not only the expression of genes related to collagens and glycolysis, but also chondrocyte apoptosis did not demonstrate significant differences in mice co-treated with MPS and HIF-1α inhibitor. And the effects observed in HIF-1α activator-treated chondrocytes were similar to those induced by MPS. And HIF-1α degraded collagens in cartilage by upregulating its downstream target genes matrix metalloproteinases. The results of activator/inhibitor of endoplasmic reticulum stress (ERS) pathway revealed that the high apoptosis rate induced by MPS was related to the ERS pathway, which was also affected by HIF-1α. Furthermore, HIF-1α affected glucose metabolism in cartilage by increasing the expression of glycolysis-related genes. In conclusion, HIF-1α plays a vital role in the pathogenesis of SONFH by regulating ECM homeostasis, chondrocyte apoptosis, and glycolysis.

Development of a risk-predicting score for hip preservation with bone grafting therapy for osteonecrosis

Identification and differentiation of appropriate indications on hip preserving with bone grafting therapy remains a crucial challenge in the treatment of osteonecrosis of the femoral head (ONFH). A prospective cohort study on bone grafting therapy for ONFH aimed to evaluate hip survival rates, and to establish a risk scoring derived from potential risk factors (multivariable model) for hip preservation. Eight variables were identified to be strongly correlated with a decreased rate of hip survival post-therapy, and a comprehensive risk scoring was developed for predicting hip-preservation outcomes. The C-index stood at 0.72, and the areas under the receiver operating characteristics for the risk score's 5- and 10-year hip failure event predictions were 0.74 and 0.72, respectively. This risk score outperforms conventional methods in forecasting hip preservation. Bone grafting shows sustained benefits in treating ONFH when applied under the right indications. Furthermore, the risk scoring proves valuable as a decision-making tool, facilitating risk stratification for ONFH treatments in future.

Automatic planning and geometric analysis of the drilling path in core decompression surgery for osteonecrosis of the femoral head

BACKGROUND AND OBJECTIVE

Core decompression surgery is an effective treatment method for patients with pre-collapse osteonecrosis of the femoral head (ONFH). The treatment relies on accurately predrilling the wire into the necrotic lesion. However, the surgical planning of this drilling path remains unclear. This paper aims to develop a framework to automatically plan the drilling path and analyze its geometric parameters.

METHODOLOGY

The proposed system consists of two stages. The first stage is to detect the key points. Besides the entry point and target point for the drilling path, the center of the femoral head (FH) and the boundary points of the necrotic lesion are also detected for the subsequent geometric analysis. In the second stage, the geometric parameters of the drilling path are analyzed, including the size of the necrotic lesion, the length from the entry point to the target point, the relative location between the FH center and the necrosis center, and the angular range of the drilling path in the anterior-posterior (AP) direction and superior-inferior (SI) direction.

RESULTS

All of the drilling paths designed by the proposed system were considered successful, starting from the proximal subtrochanteric region, terminating at the center of the necrotic lesion, and remaining within the femoral neck. The relative coordinates of the centers of the femoral head and necrotic lesion were (-0.89,5.14,2.63) mm for the left femurs and (1.55,5.92,2.63) mm for the right femurs, on average. The angular range of the drilling path was 39.99±29.58 degrees in the SI direction and 46.18±40.73 degrees in the AP direction.

CONCLUSION

This study develops a framework that allows for automatic planning and geometric analysis of the drilling path in core decompression surgery. The target point of the drilling path primarily resides in the lateral-anterior-superior region relative to the femoral head center. Surgeons and researchers can benefit from our unified framework while still maintaining the flexibility to adapt to variations in surgical cases.

Anti-sclerostin antibody therapy prevents post-ischemic osteonecrosis bone collapse via interleukin-6 association

Osteonecrosis of the femoral head (ONFH) is a debilitating condition characterized by subchondral bone necrosis, which frequently culminates in joint destruction. Although total hip arthroplasty is conventionally practiced to remediate ONFH, for patients under the age of 60, the outcomes can be suboptimal. Chronic inflammation, particularly that mediated by interleukin-6 (IL-6), has been conjectured to be a potential mechanism underlying the etiology of ONFH. This study aimed at exploring the interplay between IL-6, the canonical Wnt signaling pathway, and ONFH to provide insights for potential therapeutic interventions. Human ONFH specimens depicted an elevation in β-catenin expression in the transitional layer, while IL-6 levels were pronounced in the same region. Subsequently, mouse models of ischemic osteonecrosis were treated with an anti-sclerostin antibody to assess its effects on bone metabolism and cellular processes. Histological analysis revealed that the administration of anti-sclerostin antibodies effectuated early recovery from bone necrosis, reduced empty lacunae, and suppressed IL-6 expression. The treatment evidently initiated the activation of the Wnt/β-catenin signaling pathway, presenting a potential mechanism associated with IL-6-mediated inflammation. Furthermore, the antibody upregulated osteoblast formation, downregulated osteoclast formation, and increased bone volume. Micro-CT imaging demonstrated increased bone volume, prevented epiphyseal deformity, and improved compression strength. Therefore, this study yields significant findings, indicating the potency of anti-sclerostin antibodies in effectively modulating the Wnt/β-catenin pathway, associating with IL-6 expression, and preventing post-ONFH bone collapse. Additionally, this preclinical investigation in mouse models offers an avenue for prospective research on potential therapeutic interventions against human ONFH.

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.

Investigational regenerative medicine for non-traumatic osteonecrosis of the femoral head: a survey of registered clinical trials

INTRODUCTION

Osteonecrosis of the femoral head (ONFH) is a refractory disease requiring joint replacement in young patients. Regenerative therapies have been developed.

AREAS COVERED

This study surveyed clinical trials on regenerative medicine for ONFH. We extracted clinical trials on non-traumatic ONFH from the websites of five publicly available major registries (EuropeanUnion Clinical Trials Register ([EU-CTR],ClinicalTrials.gov, Chinese ClinicalTrial Registry [ChiCTR], University Hospital Medical InformationNetwork - Clinical Trial Registry [UMIN-CTR] and Australian New Zealand Clinical Trials Registry [ANZCTR]).The trials were classified into six categories based on purpose: surgical treatment, non-drug conservative treatment, conservative drug treatment, therapeutic strategy, diagnosis and pathogenesis, and regenerative therapy.) We extracted 169 clinical trials on ONFH. Of these, 37 were on regenerative medicine, including 29 on cell therapy. Surgical treatment was the most common treatment, followed by regenerative therapy.There were 9 clinical trials registered in the EU-CTR, with 5 on regenerative medicine; 79 trials registered on ClinicalTrials.gov, with 24 on regenerativemedicine; 54 trials registered in the ChiCTR, with 6 on regenerative medicine.

EXPERT OPINION

The focus of the joint-preserving surgery has shifted to regenerative therapy based on using cell therapy in early-stage ONFH. The global standardisation of regenerative therapy is still ongoing.

Core decompression combined with platelet-rich plasma-augmented bone grafting for femur head necrosis: a systematic review and meta-analysis

BACKGROUND

The clinical potential of biologic augmentation in core decompression and bone grafting for femoral head necrosis is widely acknowledged, with platelet-rich plasma (PRP) being a frequently employed biologic adjunct. However, its clinical application is not standardized, and high-level evidence is lacking. This study aimed to evaluate the efficacy and safety of core decompression and bone grafting combined with PRP for femur head necrosis.

METHODS

Several databases were systematically retrieved for randomized controlled trials comparing core decompression and bone grafting combined with or without PRP. A systematic review and meta-analysis were conducted following the PRISMA 2020 and AMSTAR 2 guidelines. The study is registered with PROSPERO under the code CRD42022361007, and it is also listed in the research registry under the identification number reviewregistry1537.

RESULTS

Eleven studies with 642 participants (742 hips) were included. The pooled estimates revealed that when core decompression and bone grafting were combined with PRP, the Harris hip score (mean difference: 7.98; 95% CI: 5.77-10.20; P <0.001), visual analog scale (SMD: -0.68; 95% CI: -0.96 - -0.40; P <0.001) and the pain component of Harris hip score (SMD: 8.4; 95% CI: 4.12-12.68; P <0.001), and reduction of radiographic progression [risk ratio (RR): 0.40; 95% CI: 0.27-0.59; P <0.001] were superior to core decompression and bone grafting alone. Fewer patients with treatment failure (RR: 0.27; 95% CI: 0.14-0.52; P <0.001) and higher good-to-excellent results (RR: 1.48; 95% CI: 1.17-1.86; P <0.001) were observed in treatment groups than control groups. Meanwhile, the pooled analysis substantiated the superior safety profile of PRP (RR: 0.29; 95% CI: 0.11-0.77; P =0.01).

CONCLUSIONS

The combination of core decompression and bone grafting with PRP is superior to the approach without PRP, demonstrating enhanced effectiveness in terms of function, pain relief, and radiographic progression. Additionally, it results in lower rates of treatment failure and adverse events. However, further high-quality RCTs are needed to evaluate their effectiveness due to methodological and implementation limitations observed in the existing evidence.

A Comparative Analysis of Osteochondritis Dissecans and Avascular Necrosis: A Comprehensive Review

Musculoskeletal disorders, standing as the fifth leading cause of disability-adjusted life years globally, present significant challenges in orthopedics. Osteochondritis dissecans (OCD) and avascular necrosis (AVN) are distinct but closely related conditions within this spectrum, impacting patients' quality of life with pain, limited mobility, and dysfunction. OCD, involving cartilage and bone detachment in joints, predominantly affects young athletes, but its exact etiology and optimal management remain subjects of ongoing research. Conversely, AVN, marked by bone tissue death due to compromised blood supply, is linked to systemic factors like corticosteroid use and traumatic injuries. Diagnosis for both conditions relies on radiography and magnetic resonance imaging. Conservative treatment for AVN includes the use of a cane or crutches, pharmacological therapy, or physical therapy. On the other hand, in OCD, the primary approach is activity/sports restriction. Surgical treatment options for AVN patients encompass core decompression, bone grafting, or, in the most advanced cases, total hip arthroplasty. OCD may be surgically treated through subchondral drilling or fixation of unstable lesions. Advanced cases of OCD involve cartilage salvage with resurfacing techniques. The presentation of differences between these conditions enhances our understanding, facilitating improved diagnosis and management strategies.

The Duration of Hardware Retention After Radiologic Union of Surgically Treated Femoral Neck Fractures in Children May Predict the Aggravation or Occurrence of Avascular Necrosis of the Femoral Head or Neck After Hardware Removal

BACKGROUND

The incidence of aggravation or occurrence of avascular necrosis (AVN) following hardware removal in surgically treated pediatric femoral neck fractures who achieved radiologic consolidation is unknown. This study aimed to investigate the risk factors for this complication.

METHODS

Seventy-one pediatric (mean age: 9.8±3.9 y) were retrospectively analyzed. Risk factors (age, sex, laterality, severity of initial displacement, type of fracture, time from trauma to reduction, reduction and fixation method, quality of reduction, time required to achieve radiologic union, duration of hardware retention, presence of AVN before hardware removal and follow-up time) were recorded. The severity of AVN was assessed based on radiographs with Ratliff's classification.

RESULTS

Following hardware removal, the aggravation/occurrence of AVN was detected in 11 hips (15.5%). Among the 5 hips (7%) with aggravation of AVN, 1 (1.4%) with type II AVN and 3 (4.2%) with type III AVN exhibited aggravation of type I AVN, while the remaining hip (1.4%; type I) showed enlargement of the involved AVN area. Six hips (8.5%) developed AVN following hardware removal: 2 (2.8%) were classified as type I and 4 (5.6%) as type III. Receiver operating characteristic curve analysis indicated that hardware retention >7 months after union is associated with a decreased rate of aggravation or occurrence of AVN of the femoral neck or head following hardware removal.

CONCLUSIONS

The incidence of aggravation or occurrence of AVN following hardware removal in surgically treated pediatric femoral neck fractures is 15.5%; hardware retention >7 months after radiologic union may reduce the risk of aggravation or occurrence of AVN of the femoral neck or head postimplant removal.

LEVEL OF EVIDENCE

Level III.

Preclinical models for studying corticosteroid-induced osteonecrosis of the femoral head

Nontraumatic osteonecrosis of the femoral head (ONFH) is a refractory condition that commonly results in femoral head collapse and degenerative arthritis of the hip. In the early stages, surgical procedures for hip preservation, including core decompression (CD), have been developed to prevent progressive collapse of the femoral head. Optimization of bone regeneration and biological augmentation may further enhance the therapeutic efficacy of CD for ONFH. Thus, combining CD with cell-based therapy has recently been proposed. In fact, patients treated with cell-based therapy using autologous bone marrow concentrate demonstrate improved survivorship of the femoral head, compared with conventional CD alone. Preclinical research studies to investigate adjunctive therapies for CD often utilize the rabbit model of corticosteroid-induced ONFH. Mesenchymal stem cells (MSCs) are known to promote osteogenesis and angiogenesis, and decrease inflammation in bone. Local drug delivery systems have the potential to achieve targeted therapeutic effects by precisely controlling the drug release rate. Scaffolds can provide an osteoconductive structural framework to facilitate the repair of osteonecrotic bone tissue. We focused on the combination of both cell-based and scaffold-based therapies for bone tissue regeneration in ONFH. We hypothesized that combining CD and osteoconductive scaffolds would provide mechanical strength and structural cell guidance; and that combining CD and genetically modified (GM) MSCs to express relevant cytokines, chemokines, and growth factors would promote bone tissue repair. We developed GM MSCs that overexpress the anti-inflammatory, pro-reconstructive cytokines platelet-derived growth factor-BB to provide MSCs with additional benefits and investigated the efficacy of combinations of these GM MSCs and scaffolds for treatment of ONFH in skeletally mature male New Zealand white rabbits. In the future, the long-term safety, efficacy, durability, and cost-effectiveness of these and other biological and mechanical treatments must be demonstrated for the patients affected by ONFH.

Autologous bone plug-sliding with core decompression and bone marrow aspirate concentrate application: a joint-preserving surgical technique for corticosteroid-induced osteonecrosis of femoral head

This study aimed to describe a surgical procedure for the management of corticosteroid-induced osteonecrosis of the femoral head (ONFH) and report its clinical results. The technique included harvesting a bone plug from the lateral femoral neck, core decompression, and bone marrow aspirate concentrate (BMAC) application; the procedure was completed by press-fit insertion of the autologous bone plug in the debrided area. Autologous bone plug-sliding with core decompression and bone marrow concentrate aspirate application provides good clinical outcomes in the management of ONFH. A retrospective review was performed using records of patients operated on between October 2019 and June 2021. Only patients with Ficat-Arlet stage-2 ONFH, who underwent the procedure described, were included. Twenty- nine hips (18 patients) were included and evaluated clinically and radiologically. Clinical evaluation included the Harris hip score (HHS) and Visual analogue scale (VAS) for pain, while radiological evaluation included direct radiographs. The average age was 39.8 years (± 11.7, range: 24-65 years). The average follow-up was 13.5 months (± 3.4, range: 8-19 months). There were improvements in the VAS pain and Harris hip scores in all patients. Average HHS increased from 61.90 to 87.45 (p < 0.001), while the average VAS pain score decreased from 7.14 to 3.27 (p < 0.001). No complications were encountered in any of the patients during the follow-up. None of the patients had femoral head collapse on the latest radiograph or required total hip replacement. The combination of the novel autologous bone plug-sliding method with conventional regenerative methods is a successful treatment choice for ONFH.

Femoral Head Osteonecrosis: Computed Tomography Not Needed to Identify Collapse When Using the Association Research Circulation Osseous Staging System

Background

The 2019 Revised Association Research Circulation Osseous (ARCO) Staging Criteria for Osteonecrosis of the Femoral Head (ONFH) only requires plain radiographs and magnetic resonance imaging (MRI) to diagnose and stage ONFH; however, the effectiveness of the 2019 ARCO criteria in the absence of computed tomography (CT) scans has not been investigated. Therefore, the purpose of this study was to evaluate whether CT scanning is a necessary modality for diagnosing/staging ONFH using the ARCO staging system. More specifically, do CT scans help differentiate pre- and post-collapse lesions more than MRI scans?

Methods

A study was conducted on 228 ONFH patients diagnosed between January 1, 2008, and December 31, 2018, at a single academic medical center. CT and MRI scans were reviewed by the senior author and other contributors. The ONFH classification was compared between the 2 scans to determine if CT scans were able to further differentiate staging of collapsed lesions vs MRI scans.

Results

A diagnosis of ONFH was made by MRI first in 57% (129/228) while 21% (48/228) used MRI and CT simultaneously. Only 22% (51/228) of cases were diagnosed by CT scans first. There were no cases where collapse was found by a CT scan that were not diagnosed by standard x-rays and/or MRIs.

Conclusions

CT scans are not a useful adjunct for diagnosing or treating ONFH and are not necessary if MRI is ordered when using the Revised ARCO Staging System for ONFH diagnosis.

A Comprehensive Review of Treatment Strategies for Early Avascular Necrosis

Avascular necrosis (AVN), characterised by compromised blood supply leading to bone necrosis, poses a significant challenge in orthopaedic and rheumatologic practice. This review comprehensively examines early AVN treatment strategies, including aetiology and risk factors, clinical presentation, conservative and surgical approaches, emerging therapies, and rehabilitation. Key findings underscore the importance of early detection, personalised treatment plans, and a multidisciplinary approach involving orthopaedic specialists, rheumatologists, and physical therapists. The implications for clinical practice emphasise individualised care, staying abreast of emerging therapies, and patient education. Recommendations for future management strategies highlight the need for imaging technology advancements, regenerative therapies integration, and ongoing research into genetic and molecular pathways. As the field continues to evolve, translating research findings into clinical practice holds promise for improving outcomes and enhancing the overall quality of life for individuals affected by AVN.

Did the COVID-19 Pandemic Coincide With an Increase in Osteonecrosis as Indication for Total Hip Arthroplasty in Older Patients?

BACKGROUND

Osteonecrosis of the femoral head is a common indication for total hip arthroplasty (THA). It is unclear to what extent the COVID-19 pandemic has impacted its incidence. Theoretically, the combination of microvascular thromboses and corticosteroid use in patients who have COVID-19 may increase the risk of osteonecrosis. We aimed to (1) assess recent osteonecrosis trends and (2) investigate if a history of COVID-19 diagnosis is associated with osteonecrosis.

METHODS

This retrospective cohort study utilized a large national database between 2016 and 2021. Osteonecrosis incidence in 2016 to 2019 was compared to 2020 to 2021. Secondly, utilizing a cohort from April 2020 through December 2021, we investigated whether a prior COVID-19 diagnosis was associated with osteonecrosis. For both comparisons, Chi-square tests were applied.

RESULTS

Among 1,127,796 THAs performed between 2016 and 2021, we found an osteonecrosis incidence of 1.6% (n = 5,812) in 2020 to 2021 compared to 1.4% (n = 10,974) in 2016 to 2019; P < .0001. Furthermore, using April 2020 to December 2021 data from 248,183 THAs, we found that osteonecrosis was more common among those who had a history of COVID-19 (3.9%; 130 of 3,313) compared to patients who had no COVID-19 history (3.0%; 7,266 of 244,870); P = .001).

CONCLUSION

Osteonecrosis incidence was higher in 2020 to 2021 compared to previous years and a previous COVID-19 diagnosis was associated with a greater likelihood of osteonecrosis. These findings suggest a role of the COVID-19 pandemic on an increased osteonecrosis incidence. Continued monitoring is necessary to fully understand the impact of the COVID-19 pandemic on THA care and outcomes.

[Anatomic study and clinical application of iliac crest chimeric tissue flap]

Objective

To conduct anatomical study on the iliac crest chimeric tissue flap and summarize its effectiveness of clinical application in repairing limb wounds.

Methods

Latex perfusion and anatomical study were performed on 6 fresh adult cadaver specimens with 12 sides, to observe the initial location, distribution, quantity, and direction of the common circumflexa iliac artery, the deep circumflexa iliac artery, and the superficial circumflexa iliac artery, and to measure their initial external diameter. Between December 2020 and September 2022, the iliac crest chimeric tissue flap repair was performed on 5 patients with soft tissue of limbs and bone defects. There were 3 males and 2 females, with an average age of 46 years (range, 23-60 years). Among them, there were 3 cases of radii and skin soft tissue defects and 2 cases of tibia and skin soft tissue defects. The length of bone defects was 4-8 cm and the area of skin soft tissue defects ranged from 9 cm×5 cm to 15 cm×6 cm. The length of the iliac flap was 4-8 cm and the area of skin flap ranged from 12.0 cm×5.5 cm to 16.0 cm×8.0 cm. The donor sites were directly sutured.

Results

Anatomical studies showed that there were 10 common circumflex iliac arteries in 5 specimens, which originated from the lateral or posterolateral side of the transition between the external iliac artery and the femoral artery, with a length of 1.2-1.6 cm and an initial external diameter of 0.8-1.4 mm. In 1 specimen without common circumflexa iliac artery, the superficial and deep circumflex iliac arteries originated from the external iliac artery and the femoral artery, respectively, while the rest originated from the common circumflex iliac artery. The length of superficial circumflex iliac artery was 4.6-6.7 cm, and the initial external diameter was 0.4-0.8 mm. There were 3-6 perforator vessels along the way. The length of deep circumflex iliac artery was 7.8-9.2 cm, and the initial external diameter was 0.5-0.7 mm. There were 3-5 muscular branches, 4-6 periosteal branches, and 2-3 musculocutaneous branches along the way. Based on the anatomical observation results, all iliac crest chimeric tissue flaps were successfully resected and survived after operation. The wounds at recipient and donor sites healed by first intention. All patients were followed up 8-24 months, with an average of 12 months. The tissue flap has good appearance and soft texture. X-ray film reexamination showed that all the osteotomy healed, and no obvious bone resorption was observed during follow-up.

Conclusion

The common circumflex iliac artery, deep circumflex iliac artery, and superficial circumflex iliac artery were anatomically constant, and it was safe and reliable to use iliac crest chimeric tissue flap in repairing the soft tissue and bone defects of limbs.

Comparison between osteonecrosis of the humeral and femoral heads - epidemiological analysis of the surgical trend using the nationwide claims database of the republic of Korea

BACKGROUNDS

The humeral head is the second most common site of osteonecrosis, after the femoral head. However, compared to osteonecrosis of the femoral head (ONFH), epidemiological information on osteonecrosis of the humeral head (ONHH) is scarce. We hypothesised that different biomechanical properties of the shoulder from the hip joint might present different epidemiological characteristics of ONHH from those of the ONFH. To evaluate epidemiological differences, we compared trends in the surgical treatment of ONHH and ONFH using the nationwide medical claims database of the Republic of Korea (ROK).

METHODS

We analysed epidemiological data from the Health Insurance Review and Assessment (HIRA) database of the ROK between 2008 and 2018. HIRA database contains almost all medical information in an anonymised form, including demographics, diagnoses, and types of surgical procedures, generated through healthcare practices in ROK. The annual incidence rates of ONHH and ONFH were calculated based on the total number of the general population. Demographics, annual incidence, and the proportion of post-traumatic osteonecrosis and surgical procedures were compared according to the anatomical site and the affected year.

RESULTS

The total number of patients treated for ONHH and ONFH during the study period was 1,028 and 66,260, respectively. Although the incidence of ONHH increased, it is a relatively rare disease compared to ONFH. ONHH occurred more frequently in females, while ONFH occurred predominantly in male patients (p < 0.001). Surgical treatment for ONHH was most frequently performed in older patients (63.7%), whereas middle-aged patients had the largest proportion of ONFH (48.9%, p < 0.001). The proportion of post-traumatic osteonecrosis was significantly higher in the ONHH (5.1%) than in the ONFH (1.9%, p < 0.001). Arthroplasty was performed more frequently in the ONHH (96.0%) than in the ONFH (92.9%, p < 0.001).

CONCLUSION

Despite the anatomical similarities between the hip and shoulder joints, the different biomechanical properties, such as weight-bearing functions, might cause epidemiological differences between ONHH and ONFH.

Increased Risk of In-Hospital Complications and Costs After Total Hip Arthroplasty for Primary and Secondary Osteonecrosis

BACKGROUND

An increasing proportion of patients are undergoing total hip arthroplasty (THA) for osteonecrosis (ON). Comorbid conditions and surgical risk factors are known to be greater in ON patients compared with patients who have osteoarthritis (OA) alone. The purpose of our study was to quantify the specific in-hospital complications and resource utilization associated with patients undergoing THA for ON versus OA.

METHODS

A large national database was queried to identify patients undergoing primary THA from January 1, 2016 to December 31, 2019. A total of 1,383,880 OA, 21,080 primary ON, and 54,335 secondary ON patients were identified. Demographics, in-hospital complications, costs, lengths of stay, and discharge dispositions for primary and secondary ON cohorts were compared to OA only. Age, race, ethnicity, comorbidities, Medicaid, and income status were controlled with binary logistic regression analyses.

RESULTS

The ON patients were often younger, African American or Hispanic, and had more comorbidities. Those undergoing THA for primary and secondary ON had a significantly higher risk of perioperative complications, including myocardial infarction, postoperative blood transfusion, and intraoperative bleeding. Total hospital costs and lengths of stay were significantly higher for both primary ON and secondary ON and both cohorts were less likely to be discharged home.

CONCLUSION

While rates of most complications have decreased over recent decades in ON patients undergoing THA, the ON patients still have worse outcomes even when controlling for comorbidity differences. Bundled payment systems and perioperative management strategies for these different patient cohorts should be considered separately.

Restoration of Hip Geometry after Femoral Neck Fracture: A Comparison of the Femoral Neck System (FNS) and the Dynamic Hip Screw (DHS)

BACKGROUND

The femoral neck system (FNS) was introduced as a minimally invasive fixation device for managing femoral neck fractures.

OBJECTIVE

To compare radiographic, clinical, and patient-reported outcome measures (PROMs) of femoral neck fracture patients following FNS compared to dynamic hip screw (DHS) implantation combined with an anti-rotational screw.

METHODS

Patients who underwent closed reduction and internal fixation of a femoral neck fracture between 2020 and 2022 were retrospectively included. We measured leg length, femoral offset, and centrum-collum-diaphyseal (CCD) angle in plain radiographs. Scar length, Harris Hip Score, short-form health survey 36-item score (SF-36), and Numeric Rating Scale (NRS) were assessed during follow-up visits.

RESULTS

We included 43 patients (22 females) with a median age of 66 (IQR 57, 75). In both groups, leg length differences between the injured and the contralateral side increased, and femoral offset and CCD angle differences were maintained over time. FNS patients had shorter scars and reported fewer emotional problems and more energy. There were no differences between groups regarding the remaining SF-36 sub-scores, Harris Hip Score, and NRS.

CONCLUSIONS

The FNS allows for a comparable leg length, femoral offset, and CCD angle reconstruction while achieving similarly high functional and global health scores to the DHS.

Extracellular vesicles from human umbilical cord mesenchymal stem cells prevent steroid-induced avascular necrosis of the femoral head via the PI3K/AKT pathway

Extracellular vesicles (EVs) secreted by human umbilical cord mesenchymal stem cells (hucMSC) have excellent therapeutic potential for many diseases. The aim of this study was to define the role of hucMSC-EVs in the prevention and treatment of steroid-induced avascular necrosis of the femoral head (SANFH). After establishing the SANFH rat model, the effects of hucMSC-EVs were assessed by measuring the microstructure of the femoral head using HE staining, micro-computed tomography (micro-CT), and TUNEL staining. The administration of hucMSC-EVs caused a significant reduction to glucocorticoids (GCs)-induced osteoblast apoptosis and empty lacuna of the femoral head, while effectively improving the microstructure. HucMSC-EVs rescued the deactivation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway induced by GCs, and reversed the proliferation and migration of osteoblasts inhibited by GCs. In addition, hucMSC-EVs attenuated the inhibitory effects of GCs on rat osteoblast osteogenesis, angiogenesis of endothelial cells, and prevented osteoblast apoptosis. However, the promoting effects of hucMSC-EVs were abolished following the blockade of PI3K/AKT on osteoblasts. hucMSC-EVs were found to prevent glucocorticoid-induced femoral head necrosis in rats through the PI3K/AKT pathway.

Who is the convict; COVID-19 or corticosteroid? Late onset avascular necrosis of hips after COVID-19. A case report with literature review

AIM

Avascular necrosis (AVN) or osteonecrosis is characterized by death of bone tissue due to endothelial damage and vascular abnormality. Coronavirus can induce endothelial damage and abnormal blood clotting, so that COVID-19 is known as a vascular disease. We aim to evaluate the relationship between AVN and COVID-19.

CASE

Here we present a 39-year old man with severe COVID-19 and corticosteroid consumption who developed late onset AVN of both hips 20 month after COVID-19.

CONCLUSION

An awareness of the possible osteonecrosis for all physicians dealing with patients with musculoskeletal problems following COVID-19 is necessary.