Diagnosis of Osteonecrosis of the Femoral Head: Too Little, Too Late, and Independent of Etiology

Exosomal miR-1a-3p derived from glucocorticoid-stimulated M1 macrophages promotes the adipogenic differentiation of BMSCs in glucocorticoid-associated osteonecrosis of the femoral head by targeting Cebpz

BACKGROUND

By interacting with bone marrow mesenchymal stem cells (BMSCs) and regulating their function through exosomes, bone macrophages play crucial roles in various bone-related diseases. Research has highlighted a notable increase in the number of M1 macrophages in glucocorticoid-associated osteonecrosis of the femoral head (GA-ONFH). Nevertheless, the intricate crosstalk between M1 macrophages and BMSCs in the glucocorticoid-stimulated environment has not been fully elucidated, and the underlying regulatory mechanisms involved in the occurrence of GA-ONFH remain unclear.

METHODS

We employed in vivo mouse models and clinical samples from GA-ONFH patients to investigate the interactions between M1 macrophages and BMSCs. Immunofluorescence staining was used to assess the colocalization of M1 macrophages and BMSCs. Flow cytometry and transcriptomic analysis were performed to evaluate the impact of exosomes derived from normal (n-M1) and glucocorticoid-stimulated M1 macrophages (GC-M1) on BMSC differentiation. Additionally, miR-1a-3p expression was altered in vitro and in vivo to assess its role in regulating adipogenic differentiation.

RESULTS

In vivo, the colocalization of M1 macrophages and BMSCs was observed, and an increase in M1 macrophage numbers and a decrease in bone repair capabilities were further confirmed in both GA-ONFH patients and mouse models. Both n-M1 and GC-M1 were identified as contributors to the inhibition of osteogenic differentiation in BMSCs to a certain extent via exosome secretion. More importantly, exosomes derived from GC-M1 macrophages exhibited a heightened capacity to regulate the adipogenic differentiation of BMSCs, which was mediated by miR-1a-3p. In vivo and in vitro, miR-1a-3p promoted the adipogenic differentiation of BMSCs by targeting Cebpz and played an important role in the onset and progression of GA-ONFH.

CONCLUSION

We demonstrated that exosomes derived from GC-M1 macrophages disrupt the balance between osteogenic and adipogenic differentiation in BMSCs, contributing to the pathogenesis of GA-ONFH. Inhibiting miR-1a-3p expression, both in vitro and in vivo, significantly mitigates the preferential adipogenic differentiation of BMSCs, thus slowing the progression of GA-ONFH. These findings provide new insights into the regulatory mechanisms underlying GA-ONFH and highlight potential therapeutic targets for intervention.

Effect of Corticosteroid Use on the Occurrence and Progression of Osteonecrosis of the Femoral Head: A Nationwide Nested Case-Control Study

BACKGROUND

Although it is very well known that corticosteroids cause osteonecrosis of the femoral head (ONFH), it is unclear as to which patients develop ONFH. Additionally, there are no studies on the association between corticosteroid use and femoral head collapse in ONFH patients. We aimed to investigate the association between corticosteroid use and the risk of ONFH among the general population and what factors affect ONFH occurrence. Additionally, we aimed to demonstrate which factors affect femoral head collapse and total hip arthroplasty (THA) after ONFH occurrence.

METHODS

A nationwide, nested case-control study was conducted with data from the National Health Insurance Service Physical Health Examination Cohort (2002 to 2019) in the Republic of Korea. We defined ONFH (N = 3,500) using diagnosis and treatment codes. Patients who had ONFH were matched 1:5 to form a control group based on the variables of birth year, sex, and follow-up duration. Additionally, in patients who have ONFH, we looked for risk factors for progression to THA.

RESULTS

Compared with the control group, ONFH patients had a low household income and had more diabetes, hypertension, dyslipidemia, and heavy alcohol use (drinking more than 3 to 7 drinks per week). Systemic corticosteroid use (≥1,800 mg) was significantly associated with an increased risk of ONFH incidence. However, lipid profiles, corticosteroid prescription, and cumulative doses of corticosteroid did not affect the progression to THA.

CONCLUSIONS

The ONFH risk increased rapidly when cumulative prednisolone use was ≥1,800 mg. However, oral or high-dose intravenous corticosteroid use and cumulative dose did not affect the prognosis of ONFH. Since the occurrence and prognosis of ONFH are complex and multifactorial processes, further study is needed.

Risk Factors for Femoral Head Collapse in Osteonecrosis

BACKGROUND

Osteonecrosis of the femoral head (ONFH) affects at least 20,000 patients annually in the United States; however, the pathophysiology of disease progression is poorly understood. The purpose of this study was to determine the relative importance of three distinct elements and their relationship to the collapse of the femoral head as follows: (1) identifiable risk factors, (2) femoral head anatomy, and (3) the extent of the necrotic lesion.

METHODS

A single-center retrospective cohort study was performed on patients ≥ 18 year old who presented with ONFH. Ficat classification and femoral head anatomic parameters were measured on radiographs. Osteonecrotic lesion size was measured on magnetic resonance imaging using four validated methods. Multivariable regression analyses were performed to identify predictors of femoral head collapse.

RESULTS

There were 105 patients and 137 hips included in the final cohort, of which 50 (36.5%) had collapse of the femoral head. Multivariable analyses demonstrated that medical risk factors (adjusted odds ratio (aOR): 1.15), alcohol exposure (aOR: 1.23), and increased alpha angle (aOR: 4.51) were predictive of femoral head collapse. Increased femoral head offset (aOR: 0.54) was protective against collapse. An increased size of the osteonecrotic lesion was significantly predictive of collapse with all four measurement methods evaluated: three-dimensional volumetric (aOR: 3.73), modified Kerboul (aOR: 2.92), index of necrotic extent (aOR: 1.91), and modified index of necrotic extent (aOR: 2.05).

CONCLUSIONS

In an analysis of patients who had ONFH, we identified risk factors such as alcohol exposure, high alpha angle, increased lesion size, and decreased femoral offset as increasing the risk of femoral head collapse. Given the challenges of studying this patient population, large prospective studies of patients who have ONFH should seek to identify whether these factors are reliable indicators of femoral head collapse.

LEVEL OF EVIDENCE

III.

Etiology, pathology, and treatment of osteonecrosis of the femoral head in adolescents: A comprehensive review

Femoral head necrosis is a common refractory disease in orthopedics, and shows a trend of getting younger. The occurrence of femoral head necrosis in adolescents is related to the use of glucocorticoids, autoimmune diseases, trauma, and other factors. Because adolescent patients are in the period of physical development, high activity requirements, and have fertility needs in the future, treatment is relatively difficult. Early artificial joint replacement may have problems such as wear and loosening, so total hip replacement is not the preferred treatment for adolescent patients with femoral head necrosis. This article will elaborate the research progress of femoral head necrosis in adolescents from 3 aspects, and summarize the benefits and side effects of core decompression combined with autologous stem cell transplantation in the treatment of early femoral head necrosis, so as to provide clinical ideas for the treatment of femoral head necrosis in adolescents.

Identification of microtubule-associated biomarker using machine learning methods in osteonecrosis of the femoral head and osteosarcoma

Background

This study aims to explore the microtubule-associated gene signatures and molecular processes shared by osteonecrosis of the femoral head (ONFH) and osteosarcoma (OS).

Methods

Datasets from the TARGET and GEO databases were subjected to bioinformatics analysis, including the functional enrichment analysis of genes shared by ONFH and OS. Prognostic genes were identified using univariate and multivariate Cox regression analyses to develop a risk score model for predicting overall survival and immune characteristics. Furthermore, LASSO and SVM-RFE algorithms identified biomarkers for ONFH, which were validated in OS. Function prediction, ceRNA network analysis, and gene-drug interaction network construction were subsequently conducted. Biomarker expression was then validated on clinical samples by using qPCR.

Results

A total of 14 microtubule-associated disease genes were detected in ONFH and OS. Subsequently, risk score model based on four genes was then created, revealing that patients with low-risk exhibited superior survival outcomes compared with those with high-risk. Notably, ONFH with low-risk profiles may manifest an antitumor immune microenvironment. Moreover, by utilizing LASSO and SVM-RFE algorithms, four diagnostic biomarkers were pinpointed, enabling effective discrimination between patients with ONFH and healthy individuals as well as between OS and normal tissues. Additionally, 21 drugs targeting these biomarkers were predicted, and a comprehensive ceRNA network comprising four mRNAs, 71 miRNAs, and 98 lncRNAs was established. The validation of biomarker expression in clinical samples through qPCR affirmed consistency with the results of bioinformatics analysis.

Conclusion

Microtubule-associated genes may play pivotal roles in OS and ONFH. Additionally, a prognostic model was constructed, and four genes were identified as potential biomarkers and therapeutic targets for both diseases.

Osteonecrosis as a rare musculoskeletal complication in Behcet's disease- the largest case series with literature review

BACKGROUND

Behcet disease (BD) as a variable vessel vasculitis is mainly characterized by ocular involvement, genital and oral aphthosis, and erythema nodosum. However, major organ involvements including gastrointestinal involvement, nervous system, and vascular involvement are among the severe complications. Osteonecrosis is a rare complication of patients with BD. We aim to report the largest series of BD patients suffering from osteonecrosis.

METHODS

We have retrospectively reviewed all patients in Iran Behcet's Disease Registry and reported those with osteonecrosis. Patients' medication and clinical features, symptoms, and details of osteonecrosis will also be presented. Furthermore, previously reported cases will also be reviewed.

RESULTS

Seven thousand eight hundred thirty-one patients were diagnosed with BD and registered. 18 patients developed ON with an incidence of 0.22%. The most common involvement during the disease progression was oral aphthosis which appeared in 100% of patients followed by ocular involvement in 85.7% and skin involvement in 71.4%. Vascular, ocular, and nervous system involvements are significantly higher in BD patients with osteonecrosis than the other BD patients. For the management of acute episode of uveitis, deep vein thrombosis, severe gastrointestinal involvement, arterial involvement, nervous system Involvement, and joint involvement high dose of glucocorticoids is indicated.

CONCLUSIONS

ON tends to appear as a multifocal involvement in BD patients, hence, after diagnosis of ON in one joint other possible sites of ON should be investigated.

Application of Biomaterials in Treating Early Osteonecrosis of the Femoral Head: Research Progress and Future Perspectives

Osteonecrosis of the femoral head (ONFH), a progressive pathological process of femoral head ischemia and osteocyte necrosis, is a refractory orthopedic disease caused by multiple etiologies and there is no complete cure at present. With the extension of ONFH duration, osteocyte apoptosis and trabecular bone loss can decrease the load-bearing capacity of the femoral head, which leads to the collapse of the articular cartilage and subchondral bone. Therefore, an urgent clinical need exists to develop effective treatment strategies of early-stage ONFH for maintaining the hip joint function and preventing femoral head collapse. In recent years, extensive attention has been paid to the application of diverse biomaterials in treating early ONFH for sustaining the normal morphology and function of the autologous femoral head, and slowing disease progression. Herein, we review the research progress of bone grafts, metallic materials, bioceramics, bioglasses and polymer materials for early ONFH treatment, and discuss the biological mechanisms of bone repair and regeneration in the femoral-head necrotic area. We propose suggestions for future research directions, from a special perspective of improving the local microenvironment in femoral head by facilitating vessel-associated osteoclasts (VAOs) generation and coupling of bone-specific angiogenesis and osteogenesis, as well as inhibiting bone-associated osteoclasts (BAOs) and BAO-mediated bone resorption. This review can provide ideas for the research, development, and clinical application of biomaterials for treating early ONFH. STATEMENT OF SIGNIFICANCE: We believe that at least three aspects of this manuscript make it interesting to readers of the Acta Biomaterialia. First, we briefly summarize the incidence, pathogenesis, risk factors, classification criteria and treatment of early osteonecrosis of the femoral head (ONFH). Second, we review the research progress in biomaterials for early ONFH treatment and the biological mechanisms of bone repair and regeneration in femoral-head necrotic area. Third, we propose future research progress on improving the local microenvironment in femoral head by facilitating vessel-associated osteoclasts generation and coupling of bone-specific angiogenesis and osteogenesis, as well as inhibiting bone-associated osteoclasts and bone resorption. We hope this review can provide ideas for the research, development, and clinical application of biomaterials for treating early ONFH.

Etiology of avascular necrosis of the hip and shoulder. Screening for Gaucher disease

INTRODUCTION

Avascular necrosis (AON) of the hip and shoulder is a little studied disease and the predisposing risk factors for its development are not well known. A high percentage of patients are diagnosed with idiopathic osteonecrosis. This study aims to investigate the prevalence of potential etiological factors for AON and to screen for Gaucher disease among patients with idiopathic AON.

MATERIAL AND METHODS

This retrospective, single-center, observational study was conducted on patients who had at least one episode of AON of the hip or shoulder at the Hospital de Poniente (Almería, Spain) from January 2010 to December 2019. Clinical and analytical data were collected. Patients whose medical record described no etiological factors for this disease were screened for Gaucher disease.

RESULTS

The study sample consisted of 81 patients, of whom 58 were male. The mean age at presentation of AON was 45.9 years. They presented with unilateral hip necrosis (n=43), bilateral hip necrosis (n=34), bilateral hip and unilateral shoulder necrosis (n=3), and unilateral shoulder necrosis (n=1). The most frequent potential etiological factors were smoking (46.9%) and obesity (17.3%). Screening for Gaucher disease was performed in ten patients, all of whom tested negative.

CONCLUSIONS

In our study population, the main potential etiological factors the onset of AON of the shoulder or hip were smoking and obesity. A high percentage of patients were diagnosed with idiopathic AON. We believe that a more exhaustive study of less frequent risk factors should be carried out in these cases.

Analysis of Factors Influencing Postoperative Femoral Head Collapse in Patients With Ficat I, II, and III Stages of Aseptic Necrosis of the Femoral Head

OBJECTIVE

To investigate the factors influencing postoperative femoral head collapse (FHC) in patients with Ficat I, II, and III stages of aseptic necrosis of the femoral head (ANFH).

METHODS

Retrospective analysis of 178 patients with ANFH admitted to our hospital from October 2018 to October 2021 was studied, and patients were categorized into the FHC group and no FHC group according to whether FHC occurred after surgery. The influencing factors causing postoperative FHC were analyzed by univariate and multifactor logistic regression.

RESULTS

In the collapsed group, there were statistically significant differences in etiology, extent of necrosis, mechanism of injury, preoperative waiting time, Japanese Femoral Necrosis Research Society staging, distance from the tip of the tantalum rod to the center of necrosis, and Harris score after treatment ( P < 0.05). The etiology, extent of necrosis, mechanism of injury, preoperative waiting time, Japanese Femoral Osteonecrosis Research Society classification, distance between the tantalum rod tip and the center of necrosis, and Harris score after treatment were set as independent variables, and postoperative FHC in patients with Ficat I, II, and III stages of ANFH was used as the dependent variable in the univariate logistic regression analysis.

DISCUSSION

Hormonal osteonecrosis of the femur, extent of necrosis, type C1 and type C2 in the Japanese Society for the Study of Femoral Osteonecrosis staging, and distance of the tip of the tantalum rod from the center of necrosis are risk factors for postoperative FHC in patients with Ficat I, II, and III stages of ANFH.

Comparison of minimally-invasive fibular supporting of T-type with traditional bloody iliac flap metastasis for osteonecrosis of the femoral head at ARCO stage II

Purpose

Our research mainly evaluates the clinical efficacy of two surgical methods in the treatment of osteonecrosis of the femoral head (ONFH) at ARCO stage II, aiming to provide optimal hip-preserving treatment of ONFH.

Method

From October 2018 to September 2020, 48 patients (59 hips) met the inclusion criteria and randomized. 24 cases (29 hips) in experimental group were treated with minimally-invasive fibular supporting of T-type; 24 cases (30 hips) in control group were treated with traditional bloody iliac flap metastasis. We will compare some intraoperative and postoperative conditions.

Result

The operation time in experimental group was 37 (6) minutes, in control group was 130 (21.75) minutes; the length of surgical incision in two groups was 3.7 (0.7) cm and 12.85 (2.68) cm. The intraoperative blood loss in two groups was 69 (21) ml and 363 (87) ml; the postoperative VAS score of the experimental group on day 1, day 3, day 7 after surgery was 5.5 (2), 3.5 (1), 0 (1); the control group was 6 (1.75), 4 (1), 3 (1). The data differences between above groups have statistically significant. The follow-up time of two groups was (33.86 ± 5.66) months and (35.67 ± 4.69) months. The bone graft healing time in two groups was (14.21 ± 1.93) months and (13.83 ± 2.34) months. The Harris hip scores of two groups at the last follow-up were 90 (7.5) and 86.5 (8.5). The survival rates of two groups were 79.31% (23/29) and 76.67% (23/30). The difference was no statistically significant in above groups (P > 0.05).

Conclusion

The two different bone graft implantation showed satisfactory early outcomes. Compared to the control group, the experimental group has the advantages of lesser pain, lesser blood loss, lesser trauma and shorter operation time. It may be a choice as bone graft for the treatment of ONFH at early stage.

Impact of Femoral Neck Cortical Bone Defect Induced by Core Decompression on Postoperative Stability: A Finite Element Analysis

Objective

To analyze the impact of femoral neck cortical bone defect induced by core decompression on postoperative biomechanical stability using the finite element method.

Methods

Five finite element models (FEMs) were established, including the standard operating model and four models of cortical bone defects at different portions of the femoral neck (anterior, posterior, superior, and inferior). The maximum stress of the proximal femur was evaluated during normal walking and walking downstairs.

Results

Under both weight-bearing conditions, the maximum stress values of the five models were as follows: femoral neck (inferior) > femoral neck (superior) > femoral neck (posterior) > femoral neck (anterior) > standard operation. Stress concentration occurred in the areas of femoral neck cortical bone defect. Under normal walking, the maximum stress of four bone defect models and its increased percentage comparing the standard operation were as follows: anterior (17.17%), posterior (39.02%), superior (57.48%), and inferior (76.42%). The maximum stress was less than the cortical bone yield strength under normal walking conditions. Under walking downstairs, the maximum stress of four bone defect models and its increased percentage comparing the standard operation under normal walking were as follows: anterior (36.75%), posterior (67.82%), superior (83.31%), and inferior (103.65%). Under walking downstairs conditions, the maximum stress of bone defect models (anterior, posterior, and superior) was less than the yield strength of cortical bone, while the maximum stress of bone defect model (inferior) excessed yield strength value.

Conclusions

The femoral neck cortical bone defect induced by core decompression can carry out normal walking after surgery. To avoid an increased risk of fracture after surgery, walking downstairs should be avoided when the cortical bone defect is inferior to the femoral neck except for the other three positions (anterior, posterior, and superior).

The Role of Structural Deterioration and Biomechanical Changes of the Necrotic Lesion in Collapse Mechanism of Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) is a crippling disease which is due to a lack of effective therapeutic measures. Its natural progression is rapid, the internal bone structure of the femoral head changes dramatically, and the subsequent fractures and collapse cause severe hip pain and loss of hip function. Femoral head collapse is a critical turning point in the development of ONFH and is related to the prognosis of patients. Early prevention and intervention help to preserve the hip joint and delay femoral head collapse. However, the mechanism of collapse still needs to be further studied because it is affected by different complex factors. This review discusses the underlying causes of femoral head collapse from two aspects: structural degradation and regional changes of biomechanical properties in the necrotic femoral head.

Osteogenesis-Related Long Noncoding RNA GAS5 as a Novel Biomarker for Osteonecrosis of Femoral Head

Background: The lack of effective biomarkers makes it difficult to achieve early diagnosis and intervention for osteonecrosis of the femoral head (ONFH). Hence, we aimed to identify novel long noncoding RNA (lncRNA) biomarkers for ONFH.

Methods: High-throughput RNA sequencing was performed to detect lncRNA and mRNA expression levels in subchondral bone samples from three patients with ONFH and three patients with femoral neck fractures. Integrated bioinformatics analyses were conducted to identify lncRNAs associated with ONFH development and their potential functions and signaling pathways. A co-expression network was constructed based on the gene time-series expression data in GSE113253. After selecting lncRNA GAS5 as a novel biomarker for ONFH, bone marrow mesenchymal stem cell (BMSC) osteogenic differentiation assays were performed to verify the association between lncRNA GAS5 and osteogenic differentiation. Alkaline phosphatase (ALP) staining and quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to measure the osteogenic phenotype and lncRNA GAS5 expression. Finally, for further validation, ONFH rat models were established, and lncRNA GAS5 expression in subchondral bone was detected by RT-qPCR.

Results: We identified 126 and 959 differentially expressed lncRNAs and genes, respectively. lncRNA GAS5 expression level was significantly downregulated in patients with ONFH compared to the control group patients. The BMSC osteogenic differentiation assays showed that ALP activity increased gradually from days 3 to 7, while the lncRNA GAS5 expression level was significantly upregulated in the osteogenic differentiation induction groups. Furthermore, in vivo experiments suggested that the bone volume/tissue volume value and trabecular thickness significantly decreased in the ONFH rat model group compared to the control group, whereas the trabecular space significantly increased in the ONFH group compared to the control group. In addition, the lncRNA GAS5 expression level significantly decreased in the ONFH rat model group.

Conclusion: The lncRNA GAS5 expression level was highly associated with BMSC osteogenic differentiation and was significantly downregulated in both the subchondral trabecular bone tissue of ONFH patients and ONFH rat models. Therefore, lncRNA GAS5 can serve as an ONFH osteogenic biomarker to provide an effective target for early diagnosis and molecular therapy of ONFH.

Combining frog-leg lateral view may serve as a more sensitive X-ray position in monitoring collapse in osteonecrosis of the femoral head

Load-bearing capacity of the bone structures of anterolateral weight-bearing area plays an important role in the progressive collapse in osteonecrosis of the femoral head (ONFH). The purpose of this study is to assess the efficacy of combined evaluation of anteroposterior (AP) and frog-leg lateral (FLL) view in diagnosing collapse. Between December 2016 and August 2018, a total of 478 hips from 372 patients with ONFH (268 male, 104 female; mean age 37.9 ± 11.4 years) were retrospectively evaluated. All patients received standard AP and FLL views of hip joints. Japanese Investigation Committee (JIC) classification system was used to classify necrotic lesion in AP view. Anterior necrotic lesion was evaluated by FLL view. All patients with pre-collapse ONFH underwent non-operative hip-preserving therapy. The collapse rates were calculated and compared with Kaplan–Meier survival analysis with radiological collapse as endpoints. Forty-four (44/478, 9.2%) hips were classified as type A, 65 (65/478, 13.6%) as type B, 232 (232/478, 48.5%) as type C1 and 137 (137/478, 28.7%) as type C2. Three hundred cases (300/478, 62.5%) were collapsed at the initial time point. Two hundred and twenty six (226/300, 75.3%) hips and 298 (298/300, 99.3%) hips collapse were identified with AP view and FLL view, respectively. An average follow-up of 37.0 ± 32.0 months was conducted to evaluate the occurrence of collapse in 178 pre-collapse hips. Collapses occurred in 89 hips (50.0%). Seventy-seven (77/89, 86.5%) hips were determined with AP view alone and 85 (85/89, 95.5%) hips were determined with the combination of AP and FLL views. The collapse rates at five years were reported as 0% and 0%, 16.2% and 24.3%, 58.3% and 68.1% and 100% and 100% according to AP view alone or combination of AP and FLL views for types A, B, C1 and C2, respectively. The collapse can be diagnosed more accurately by combination of AP and FLL views. Besides, JIC type A and type B ONFH can be treated with conservative hip preservation, but pre-collapse type C2 ONFH should be treated with joint-preserving surgery. Type C1 needs further study to determine which subtype has potential risk of collapse.

The Therapeutic Effect of Huo Xue Tong Luo Capsules in Association Research Circulation Osseous (ARCO) Stage II Osteonecrosis of the Femoral Head: A Clinical Study With an Average Follow-up Period of 7.95 Years

Background: Huo Xue Tong Luo (HXTL) capsules are an oral preparation that could relieve pain and ameliorate osteonecrosis in patients with asymptomatic osteonecrosis of femoral head (ONFH). We wanted to verify whether it could be a treatment option for ARCO stage II ONFH.

Methods: A total of 44 patients (66 hips) with ARCO stage II ONFH were recruited from June 1996 to October 2013 (clinical trial registry number: ChiCTR-RPC-15006,290). HXTL capsules were given under a specific protocol, and the endpoint was set as femoral head collapse. The clinical indicators [including visual analog scale (VAS) and Harris Hip Score (HHS)] and radiological indicators [including Tonnis classification, ARCO stage, Japanese Investigation Committee (JIC) classification, lateral preserved angle (LPA), anterior preserved angle (APA), and combined preserved angle (CPA)] before and after treatment were compared. Kaplan–Meier survival analysis and Cox regression analysis were used to identify the risk factors associated with femoral head collapse.

Result: Twenty-six males and 18 females with an average age of 38.3 ± 2.8 were followed for an average of 7.95 years. Forty-six of the 66 (69.7%) hips had no progression in pain or collapse, and patients exhibited a higher HHS (p < 0.05) after therapy. Twenty of the 66 (30.3%) hips progressed in Tonnis classification and ARCO stage, but only one of the 66 (1.5%) hips required total hip arthroplasty (THA). The Kaplan–Meier survivorship curve suggested that the survival rates were 96.97% at 5 years, 69.15% at 10 years, and 40.33% at 15 years. Patients with type A necrotic lesions on anteroposterior (AP) and frog-leg lateral (FLL) radiographs revealed 100% survival rates. Multivariate Cox regression analysis revealed that patients with an LPA ≤ 60.9 exhibited a 3.87 times higher risk of collapse of the femoral head [95% confidence interval (CI), 1.241–5.673] than did those patients with an LPA>60.9.

Conclusion: HXTL capsules could be a treatment option for ARCO stage II ONFH, resulting in improved hip function and delayed progression to femoral head collapse, especially when the anterior and lateral portions of the femoral head were not affected. However, an LPA of less than 60.9° may be a risk factor for collapse of the femoral head.

Clinical Trial Registration:http://www.chictr.org.cn/showproj.aspx?proj=10829, identifier ChiCTR-OPC-15007030

Geographical distribution of the associated factors of osteonecrosis of the femoral head, using the designated intractable disease database in Japan

OBJECTIVES

Osteonecrosis of the femoral head (ONFH) is a designated intractable disease (DID) in Japan. The Ministry of Health, Labour, and Welfare launched an online registry system for DIDs. We aimed to investigate the epidemiological characteristics of patients with ONFH using the DID database.

METHODS

Data of patients with ONFH registered in the DID database between January 2004 and December 2013 were extracted. The incidence of new cases and distributions of sex, age, and associated risk factors were investigated. The prevalence of the two categories, 'steroid-associated' and 'alcohol-associated' risk factors, was estimated for each prefecture.

RESULTS

New 15,049 cases of ONFH were investigated. The mean registration rate-corrected annual ONFH incidence per 100,000 individuals was 1.77. The male-to-female ratio was 1.33. Age distribution peaked in the 40s and 50s for male and 60s for female. The prevalence of steroid-associated ONFH was lower in males (28.6%) than in females (49.8%), while that of alcohol-associated ONFH was higher in males (47.2%) than in females (9.3%). No clear region was identified for the steroids. The incidence of alcohol-associated ONFH was significantly higher in Tokyo and Okinawa, regardless of sex.

CONCLUSIONS

Alcohol-associated ONFH incidence varies geographically across Japan, suggesting that it has regional characteristics.

Glucocorticoid-induced osteonecrosis in systemic lupus erythematosus patients

Osteonecrosis (ON) is a complex and multifactorial complication of systemic lupus erythematosus (SLE). ON is a devastating condition that causes severe pain and compromises the quality of life. The prevalence of ON in SLE patients is variable, ranging from 1.7% to 52%. However, the pathophysiology and risk factors for ON in patients with SLE have not yet been fully determined. Several mechanisms for SLE patients' propensity to develop ON have been proposed. Glucocorticoid is a widely used therapeutic option for SLE patients and high-dose glucocorticoid therapy in SLE patients is strongly associated with the development of ON. Although the hips and knees are the most commonly affected areas, it may be present at multiple anatomical locations. Clinically, ON often remains undetected until patients feel discomfort and pain at specific sites at which point the process of bone death is already advanced. However, strategies for prevention and options for treatment are limited. Here, we review the epidemiology, risk factors, diagnosis, and treatment options for glucocorticoid-induced ON, with a specific focus on patients with SLE.

Ten-year results of mesenchymal stromal cell transplantation augmented with vascularised bone grafts for advanced osteonecrosis of the femoral head

Background

A prospective, open-label clinical trial, in which transplantation of cultured autologous bone marrow-derived multipotent mesenchymal stromal cells in combination with vascularised bone grafts for the treatment of post-collapse extensive osteonecrosis of the femoral head in ten patients, was conducted previously. The aim of this study was to assess the 10-year clinical and radiographic results of that study.

Methods

Patients were evaluated for radiographic progression of osteonecrosis of the femoral head using anteroposterior radiographs at 10 years postoperatively. Clinical score and hip function, including the timed up and go test, were also estimated.

Results

Osteoarthritic changes in the affected hip were found in five of the ten patients, two of whom had undergone total hip arthroplasty at 7 and 9 years postoperatively. Five of the six cases (83.3%) in which pre-operative femoral head collapse was less than 3 mm, had no further collapse. On the other hand, all four cases in which pre-operative femoral head collapse was ≥3 mm, showed osteoarthritic changes within 10 years. The average clinical score significantly improved postoperatively and was maintained at 10 years.

Conclusions

Considering that eight of 10 post-collapse cases could avoid total hip arthroplasty conversion with good clinical results for 10 years and five of 6 post-collapse cases (collapse <3 mm) could avoid further collapse and osteoarthritic changes for 10 years, mesenchymal stromal cell transplantation in combination with vascularised bone grafts could be an effective treatment for post-collapse osteonecrosis of the femoral head.

The efficacy of lapine preconditioned or genetically modified IL4 over-expressing bone marrow-derived mesenchymal stromal cells in corticosteroid-associated osteonecrosis of the femoral head in rabbits

Cell-based therapy for augmentation of core decompression (CD) using mesenchymal stromal cells (MSCs) is a promising treatment for early stage osteonecrosis of the femoral head (ONFH). Recently, the therapeutic potential for immunomodulation of osteogenesis using preconditioned (with pro-inflammatory cytokines) MSCs (pMSCs), or by the timely resolution of inflammation using MSCs that over-express anti-inflammatory cytokines has been described. Here, pMSCs exposed to tumor necrosis factor-alpha and lipopolysaccharide for 3 days accelerated osteogenic differentiation in vitro. Furthermore, injection of pMSCs encapsulated with injectable hydrogels into the bone tunnel facilitated angiogenesis and osteogenesis in the femoral head in vivo, using rabbit bone marrow-derived MSCs and a model of corticosteroid-associated ONFH in rabbits. In contrast, in vitro and in vivo studies demonstrated that genetically-modified MSCs that over-express IL4 (IL4-MSCs), established by using a lentiviral vector carrying the rabbit IL4 gene under the cytomegalovirus promoter, accelerated proliferation of MSCs and decreased the percentage of empty lacunae in the femoral head. Therefore, adjunctive cell-based therapy of CD using pMSCs and IL4-MSCs may hold promise to heal osteonecrotic lesions in the early stage ONFH. These interventions must be applied in a temporally sensitive fashion, without interfering with the mandatory acute inflammatory phase of bone healing.

Modified Kerboul Angle Predicts Outcome of Core Decompression With or Without Additional Cell Therapy

BACKGROUND

Core decompression is the most common procedure for early-stage osteonecrosis of the femoral head (ONFH). This study investigated outcomes of core decompression with/without bone marrow aspirate concentrate (BMAC), based on the Kerboul combined necrotic angles using magnetic resonance imaging.

METHODS

We reviewed 66 patients (83 hips) with early ONFH, Association Research Circulation Osseous stages I-IIIa, who underwent core decompression alone (26 patients, 33 hips) or in combination with BMAC (40 patients, 50 hips). Survival rate and progressive collapse were analyzed using the Kaplan-Meier method, and conversion to total hip arthroplasty (THA) was evaluated. Subgroup analyses based on the modified Kerboul angle were performed: grade I (<200°), grade II (200°-249°), grade III (250°-299°), and grade IV (≥300°).

RESULTS

Mean follow-up was 36 ± 23 months. Femoral head collapse with BMAC (16 hips, 32%) was significantly lower than without BMAC (19 hips, 58%, P = .019). Conversion THA was significantly lower with BMAC (28%) than without (58%, P = .007). Survival rates among groups showed significant differences (P = .017). In grade I, 0/12 hips with BMAC collapsed while 3/9 (33%) without BMAC collapsed (P = .063); in grade II, 2/16 hips (12%) with BMAC collapsed while 7/13 (54%) without BMAC collapsed (P = .023). There was no significant difference in collapse with (64%) or without (82%) BMAC in grade III-IV hips (P = .256).

CONCLUSION

Core decompression with/without BMAC had a high failure rate, by increasing disease progression and the necessity for THA, for combined necrotic angles >250°. In our study, addition of BMAC had more reliable outcomes than isolated core decompression for precollapse ONFH if the combined necrotic angles were <250°.

Outcomes of Cemented Total Knee Arthroplasty for Secondary Osteonecrosis of the Knee

BACKGROUND

Secondary osteonecrosis of the knee (SOK) generally occurs in relatively young patients; at advanced stages of SOK, the only viable surgical option is total knee arthroplasty (TKA). We conducted a retrospective study to investigate implant survivorship, clinical and radiographic outcomes, and complications of contemporary cemented bicompartmental TKA with/without patellar resurfacing for SOK.

METHODS

Thirty-eight cemented TKAs in 27 patients with atraumatic SOK, mean age 43 years (17 to 65), were retrospectively reviewed. Seventy-four percent had a history of corticosteroid use, and 18% had a history of alcohol abuse. Patellar osteonecrosis was coincidentally found in six knees (16%), and all were asymptomatic without joint collapse. The mean followup was 7 years (2 to 12). Knee Society Score (KSS) and radiographic outcomes were evaluated at 6 weeks, 1 year, then every 2 to 3 years.

RESULTS

Ninety-two percent had implant survivorship free from revision with significant improvement in KSS. Causes of revision included aseptic tibial loosening (one), deep infection (one), and instability with patellofemoral issues (one). Four of six cases also with patellar osteonecrosis received resurfacing, including one with periprosthetic patellar fracture after minor trauma, with satisfactory clinical results after conservative treatment. None of the unrevised knees had progressive radiolucent lines or evidence of loosening. An unresurfaced patella, use of a stem extension or a varus-valgus constrained prosthesis constituted 18%, 8% and 3%, respectively.

CONCLUSION

Cemented TKAs with selective stem extension in patients with SOK had satisfactory implant survivorship and reliable outcomes. Secondary osteonecrosis of the patella should be carefully evaluated prior to operation.

Osteonecrosis of the Femoral Head in Korean Patients with Human Immunodeficiency Virus Infection

Background

Osteonecrosis of the femoral head (ONFH) is a disabling condition that often necessitates total hip arthroplasty (THA). Although ONFH occurs more frequently among patients with human immunodeficiency virus (HIV) than among the general population, there is little epidemiological information regarding ONFH in Korean patients with HIV. In the present study, we aimed to investigate the incidence and clinical features of ONFH among Korean patients with HIV.

Materials and Methods

In this retrospective study, we reviewed the medical records of 1,250 Korean patients with HIV treated from January 1990 to December 2019. A standardised data collection sheet was used to obtain clinical information. Imaging data were analysed by a radiologist in accordance with the 2019 revised version of the Association Research Circulation Osseous (ARCO) staging system for ONFH.

Results

Among the 1,250 included patients, 13 patients (1.04%; 3 women, 10 men) were diagnosed with ONFH. The overall incidence of ONFH was 1.29 per 1,000 person-years (PYs) (95% confidence interval [CI]: 0.7 – 2.4 per 1,000 PYs). Median age among the 13 patients with ONFH was 47 years (interquartile range [IQR]: 41 – 57 years). The median duration since HIV diagnosis was 4.8 years (IQR: 2.3 – 10.1 years). The median CD4 cell count at the time of ONFH diagnosis was 381 cells/ mm³ (IQR: 161 – 551 cells/mm³). At the initial diagnosis of ONFH, 83.3% of patients exhibited bilateral involvement. ARCO stage 3 or 4 osteonecrosis was observed in 83% of patients. Among 22 hips, stage 1 ONFH was noted in 2 (9.1%), stage 2 ONFH was noted in 7 (31.8%), stage 3 ONFH was noted in 9 (40.9%), and stage 4 ONFH was noted in 4 (18.2%). THA was eventually performed in 84.6% of patients. Five (38.5%) patients had a history of steroid use, 4 (30.8%) patients had a history of alcohol abuse and 10 (76.9%) were smokers. Eight (61.5%) patients had a history of acquired immune deficiency syndrome-defining illness, including 7 with tuberculosis and 1 with pneumocystis pneumonia. Nine patients (69.2%) had a nadir CD4 cell count <200/µL, and 3 (23.1%) had a history of bone fracture. Overall, 84% of patients were exposed to antiretroviral therapy, while 54% had taken protease inhibitors for more than 1 year.

Conclusion

Considering that relatively high incidence of ONFH in patients with HIV, a high index of suspicion for those with risk factors and those with groin or hip pain for is required in HIV-infected patients.

Tumor necrosis factor inhibitors prevent structural damage in hips in ankylosing spondylitis-time to reconsider treatment guidelines? A case series and review of literature

Tumor necrosis factor inhibitors (TNFi) are indicated to treat ankylosing spondylitis (AS), also termed radiographic axial spondyloarthritis (axSpA). The main indication for TNFi is symptom relief, and whether they retard spinal structural damage as assessed by radiography is debated. Hips are the most common "non-spinal" joints involved in AS patients leading to major incapacitation. No major treatment guidelines mention measures to prevent peripheral joint damage, especially hips, in individuals with AS. We present our experience of prevention of structural damage in hips by TNFi in 4 AS patients from our practice. We conducted a literature review looking for articles describing prevention of structural damage progression in hips by TNFi. Over a 10-year period, three out of four patients were treated with TNFi and had no progression in hip damage as assessed by imaging. Only one patient that withdrew the TNFi due to infectious complications developed rapid worsening and required hip arthroplasty. Our literature review showed multiple case series with similar results suggesting that use of TNFi in patients with AS may prevent structural damage and at least postpone a hip replacement at a young age. Based on our experience, as well as from the literature review, we believe that treatment guidelines in axSpA should recommend prompt institution of TNFi following identification of hip involvement in patients to prevent a major source of disability. Whether interleukin (IL)-17 inhibitors or targeted synthetic anti-rheumatic drugs have hip sparing effects in patients with AS should also be investigated. Key Points • Hip involvement in ankylosing spondylitis is a major source of disability. • TNFi prevent hip damage in ankylosing spondylitis. • Prompt institution of TNFi should follow suspicion of hip involvement in ankylosing spondylitis.

Inflammation, Bone Healing and Osteonecrosis: From Bedside to Bench

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