Nontraumatic Osteonecrosis of the Femoral Head: Where Do We Stand Today?: A 5-Year Update

An injectable hydrogel loaded with miRNA nanocarriers promotes vessel-associated osteoclast (VAO)-mediated angiogenesis and bone regeneration in osteonecrosis of the rat femoral head

Osteonecrosis of the femoral head (ONFH) remains a significant clinical challenge. Despite various strategies aimed at promoting bone repair and halting disease progression, an effective cure remains elusive. Recent studies have identified a non-bone-resorbing osteoclast subtype, vessel-associated osteoclasts (VAOs), distinct from classical bone-associated osteoclasts (BAOs), offering new therapeutic opportunities for ONFH. Notably, we observed alterations in the populations and distributions of VAOs and BAOs in the femoral head of ONFH patients, suggesting that the imbalance between these two osteoclast subtypes contributes to ONFH pathology. Here, we developed an injectable alginate/hydroxyapatite hydrogel (AHH) loaded with graphene oxide-based miR-7b nanocarriers (GPC@miR) for ONFH treatment. The controlled release of GPC@miR from AHH/GPC@miR inhibited BAO formation by suppressing dendritic cell-specific transmembrane protein (DC-STAMP), thereby reducing bone resorption. Meanwhile, mono-/bi-nucleated VAOs were preserved and increased in number, promoting angiogenesis of type H vessels and osteogenesis via platelet-derived growth factor-BB (PDGF-BB) and vascular endothelial growth factor-A (VEGF-A) secretion. Intraosseous administration of AHH/GPC@miR rebalanced VAOs and BAOs, restored the femoral head microenvironment, and enhanced vascularization and bone regeneration in ONFH rat models. This study introduces a novel biomaterial-based strategy for ONFH repair by regulating osteoclast subtypes, providing insights into VAO-mediated angiogenesis and osteogenesis for bone regeneration.

Calcified Cartilage Zone Remodeling Induced by IL-1β Derived from Necrotic Subchondral Bone Initiates Cartilage Degeneration in Patients with Glucocorticoids-induced Osteonecrosis of the Femoral Head

Glucocorticoids-induced osteonecrosis of the femoral head (GONFH) is characterized by progressive cartilage degeneration, yet the role of calcified cartilage zone (CCZ) remodeling in this process remains poorly understood. This study investigated how the inflammatory microenvironment within necrotic subchondral bone drove CCZ remodeling and subsequent cartilage degeneration. Using osteochondral tissues from GONFH patients and interleukin-1β (IL-1β)-treated hypertrophic chondrocytes induced by ATDC5 cells, we combined histology, immunohistochemistry, scanning electron microscopy, energy dispersive spectrometer, transmission electron microscopy, nanoindentation testing, enzyme linked immunosorbent assay and fluorescent tracking to evaluate morphological, biomechanical, and molecular changes. Our findings revealed that CCZ of GONFH exhibited significant thinning, matrix decomposition, demineralization, diminished mechanical strength, and increased porosity. Spatial analysis demonstrated a strong correlation between CCZ remodeling and site-specific cartilage degeneration. Notably, IL-1β was overexpressed in necrotic subchondral bone and the site deep zones of cartilage. It potently enhanced catabolic activity in hypertrophic chondrocytes, promoting matrix metalloproteinase expression while impairing mineralization capacity. This study uncovers a novel pathological cascade in GONFH: necrotic subchondral bone-derived IL-1β drives CCZ remodeling via biomechanical and biological pathways, leading to cartilage degeneration independent of femoral head collapse. Our findings highlight IL-1β as a critical therapeutic target, providing a rationale for subchondral bone-targeted anti-inflammatory strategies to mitigate GONFH progression.

Outcomes of Core Decompression with Allograft-Bone Threaded Cage or Mineralized Collagen Threaded Scaffold for the Treatment of Early-Stage Osteonecrosis of the Femoral Head: A 10-Year Follow-Up

BACKGROUND

Osteonecrosis of the femoral head (ONFH) is a progressive condition impacting young, active individuals. To delay or avoid total hip arthroplasty (THA), joint-preserving techniques like core decompression (CD) with structural grafting are often employed. This study compared long-term (10- year) outcomes of CD combined with either an allograft-bone threaded cage (ATC) or a novel mineralized collagen threaded scaffold (MCTS).

METHODS

A retrospective cohort analysis was performed on 103 consecutively enrolled patients who had unilateral ONFH classified as Steinberg stages I to IIIA, who underwent CD with implantation of either ATC or MCTS between October 2010 and December 2014. Among these, 90 patients (87.4%) successfully completed the follow-up, while 13 patients (12.6%) were lost. The primary outcome was graft survival, assessed through Kaplan-Meier survival analysis, with THA conversion as the endpoint. Secondary outcomes included improvements in the Harris Hip Score (HHS) and radiographic evaluations of graft osteointegration.

RESULTS

At an average of 10-year follow-up, graft survival rates for the ATC and MCTS groups were 75.6 and 77.6%, respectively, with no significant intergroup difference. Both groups showed significant improvements in HHS postoperatively, though intergroup differences were non-significant. Radiographic evidence of osteointegration was observed in 92.7% of ATC cases after a mean follow-up period of 13.2 months and in 93.9% of MCTS cases following a mean follow-up of 7.6 months. Graft failure occurred between 1.2 and 7.2 years postoperatively, with failure rates remaining below 30% for early-stage ONFH (Steinberg stages I to II) but exceeding 50% for stage IIIA in both groups.

CONCLUSIONS

In patients with pre-collapse ONFH, CD combined with ATC or MCTS demonstrated comparable long-term survivorship and functional outcomes, though both their efficacy diminished in advanced stages. These findings highlight the potential viability of biomaterial scaffolds in joint-preserving interventions for early-stage ONFH and underscore the importance of early intervention.

The Prognostic Value of Antero-lateral Femoral Head Preservation Extension in Post-Collapse Femoral Head Necrosis

BACKGROUND

The extent of antero-lateral wall preservation is crucial for early osteonecrosis of the femoral head (ONFH) prognosis. This study aimed to assess the predictive value of the anterior preserved angle (APA) and lateral preserved angle (LPA) of the femoral head in post-collapse ONFH prognosis.

METHODS

There were 77 patients (102 hips) who had Association Research Circulation Osseous stage IIIA ONFH enrolled in this study, with an average follow-up of 7.3 years. Hips were categorized into the favorable and poor function groups based on the Harris hip score and whether a conversion to total hip arthroplasty occurred during follow-up. The LPA and APA were measured to quantify unaffected antero-lateral femoral head regions. Univariate and multivariate analyses were conducted to identify independent factors associated with hip function status. Cutoff values of LPA and APA were determined from receiver operating characteristic curves for predicting favorable hip function, while the survival rates were assessed using Kaplan-Meier survival analysis.

RESULTS

Ultimately, there were 49 hips in the poor function group and 52 hips in the favorable function group. Multivariate COX regression analysis identified both LPA and APA as independent protective factors for hip function. Cutoff values were 44.6° for LPA and 41.1° for APA, respectively. The 10-year survival rates with poor joint function as the endpoint were 87.5% for LPA ≥ 44.6° and 17.6% for LPA < 44.6° as well as 88.1% for APA ≥ 41.1° and 23.4% for APA < 41.1°. Similar results were obtained when considering collapse progression and secondary osteoarthritis changes as endpoints, respectively. Additionally, a satisfactory prognosis was observed when LPA ≥ 44.6° was combined with APA ≥ 41.1°.

CONCLUSIONS

In ONFH, femoral head collapse does not necessarily indicate a poor prognosis. Specifically, cases with LPA ≥ 44.6° and APA ≥ 41.1° are expected to have a favorable prognosis, enabling long-term "survival with collapse."

Clinical outcomes and risk factors for failure of nano-hydroxyapatite/polyamide 66 bracing rod combined with allogeneic bone in treatment of early-stage osteonecrosis of the femoral head

PURPOSE

This study was performed to analyse the clinical factors associated with failure of nano-hydroxyapatite/polyamide 66 (nHA/PA66) bracing rods combined with allogeneic bone in the treatment of early-stage osteonecrosis of the femoral head (ONFH).

METHODS

In total, 96 patients were treated with nHA/PA66 bracing rods combined with allogeneic bone for ONFH between October 2016 and September 2020. The patients were classified according to aetiology, Association Research Circulation Osseous (ARCO) type, Japanese Investigation Committee (JIC) type, age, and body mass index(BMI). The outcome measures were the Hip Harris Score (HHS), imaging changes, and the need for total hip arthroplasty (THA) (performed in cases of clinical failure, at which point follow-up was discontinued).

RESULTS

All patients were included in the study, with a mean follow-up duration of 50.76 ± 17.94 months. The preoperative HHS was 79.00 ± 13.61 and that at the final follow-up was 81.73 ± 17.67(P = 0.149). The excellent and good rate improved from 43.88% preoperatively to 65.47% at the final follow-up(P = 0.000). The radiographic progression rate was 36.70% and the incidence of THA was 23.02%. Univariate analysis identified ARCO type (P = 0.000), JIC type (P = 0.000), and age (P = 0.003) as independent risk factors for postoperative failure. Postoperative multivariate analysis also confirmed ARCO type, JIC classification, and age as risk factors.

CONCLUSION

This technique is not recommended for patients older than 44 years or those with ARCO type 3 or JIC type C ONFH.

Core decompression and bone marrow aspirate injection in avascular necrosis of the femoral head

To evaluate the clinical and radiological outcomes of core decompression combined with bone marrow aspirate injection (BMAI) in patients with femoral head avascular necrosis (AVN) before articular surface collapse. Twenty-two patients with AVN underwent core decompression and BMAI. The patients were followed for at least 12 months. Radiological assessments were performed using plain radiography and magnetic resonance imaging, and staging was conducted based on the Association Research Circulation Osseous system. Clinical outcomes were evaluated using the Harris Hip Score and Merle d'Aubigne-Postel scoring systems. At the 12-month follow-up, hip function scores showed significant improvement. The mean Harris Hip Score increased by 23 points (P < .001), and the mean Merle d'Aubigne-Postel score increased by 1 point (P < .001). Radiologically, all stage I lesions regressed to stage 0 (P < .001). Among stage II lesions, 83% remained stable, while progression was observed in 17%. 75% of the stage IIIA lesions showed radiological progression. Core decompression combined with BMAI effectively halts the progression of early-stage AVN, preserving joint integrity and delaying the need for total hip arthroplasty. Further studies are warranted to explore the efficacy of biological therapy in treating femoral head AVN.

Knowledge mapping of core decompression in osteonecrosis of the femoral head: a bibliometric analysis

Background

Osteonecrosis of the femoral head (ONFH), caused by disrupted blood supply leading to bone cell death and joint collapse, remains a critical orthopedic challenge. While core decompression has advanced significantly in ONFH treatment, no bibliometric analysis has mapped its research landscape.

Method

We analyzed 854 articles from the Web of Science Core Collection (1986-2023) using VOSviewer, CiteSpace, and bibliometrix.

Results

Publications surged from 5.4/year (1986-2001) to 52.3/year (2015-2023), reflecting intensified interest. China (253 articles, 29.6%) and the United States (232, 27.2%) dominated contributions, with Stanford University and Johns Hopkins University as top institutions. International collaborations linked China to the United States, Germany, and England. Clinical Orthopaedics and Related Research was the most cited journal (4708 citations). Keyword analysis revealed emerging hotspots: mesenchymal stem cells (19 occurrences), cell therapy, and angiogenesis. Citation bursts highlighted Mont MA's seminal work (burst strength: 19.67) on joint-preserving strategies and stem cell-enhanced core decompression.

Conclusion

This first bibliometric study delineates trends, collaborations, and frontiers in core decompression for ONFH, emphasizing the translational potential of stem cell therapies.

Fatty infiltration of periarticular muscles in patients with osteonecrosis of the femoral head

PURPOSE

Muscle mass and fatty infiltration can be assessed on computed tomography (CT) images using the cross-sectional area (CSA) and computed tomography attenuation value (CTV). Femoral head collapse in osteonecrosis of the femoral head (ONFH) may affect both values. We investigated factors influencing the CSA and CTV of the periarticular muscles in patients with ONFH.

METHODS

Overall, 101 patients with ONFH with unilateral hip pain (stage 2, 24 patients; stage 3 A, 49 patients; and stage 3B, 28 patients) were included. The CSA and mean CTV of the bilateral gluteus maximus (Gmax), gluteus medius (Gmed), gluteus minimus (Gmin), and iliopsoas (IP) muscles were measured using CT cross-sections. Bilateral comparisons and associations with Japanese Investigation Committee (JIC) stage were analysed. Multiple regression analysis was used to evaluate factors associated with the CSA and CTV.

RESULTS

On the symptomatic side, the CSA was significantly lower for the Gmax, Gmed, and IP, whereas the CTV was significantly lower for all tested muscles (all p < 0.01). The CTV, but not the CSA, of the Gmax, Gmed, and Gmin was significantly associated with the JIC stage severity bilaterally (all p < 0.01). Multiple regression analysis showed significant associations of the CTV with age, sex, and JIC stage (all p < 0.01).

CONCLUSION

Symptomatic ONFH leads to decreased muscle mass and increased fatty infiltration. Femoral head collapse progression is associated with a decrease in the CTV. Periarticular muscle assessment, including on the contralateral side, is important in patients with ONFH, particularly in older women.

X-ray based radiomics machine learning models for predicting collapse of early-stage osteonecrosis of femoral head

This study aimed to develop an X-ray radiomics model for predicting collapse of early-stage osteonecrosis of the femoral head (ONFH). A total of 87 patients (111 hips; training set: n = 67, test set: n = 44) with non-traumatic ONFH at Association Research Circulation Osseous (ARCO) stage II were retrospectively enrolled. Following data dimensionality reduction and feature selection, radiomics models were constructed based on anteroposterior (AP), frog-lateral (FL), and AP + FL combined view using random forest (RF), support vector machine (SVM), and stochastic gradient descent (SGD). After the optimal radiomics model was selected based on areas under the curve (AUC), its performance on the test set was compared with that of orthopaedists using receiver operating characteristic (ROC) curves and confusion matrices. Among all radiomics models, the SVM-based AP + FL combined view model (AP + FL-Rad_SVM) achieved the highest individual performance demonstrating an AUC of 0.904 (95% CI 0.829 -0.978) in the test set, which was significantly better than that of three attending surgeons (p = 0.014, 0.004, and 0.045, respectively). The SVM model based on AP + FL views of hip X-ray exhibited excellent ability in predicting the collapse of ONFH and showed superior performance compared with less experienced orthopaedic surgeons. This model may inform clinical decision-making for early-stage ONFH.

Aging and autophagic phenotypic changes in bone marrow mesenchymal stem cells in glucocorticoid-induced osteonecrosis

BACKGROUND

Glucocorticoid (GC) overuse is the main cause of osteonecrosis of the femoral head (ONFH). The dysfunction of bone marrow mesenchymal stem cells (BMSCs) plays an important role in ONFH pathogenesis. Physiological concentrations of GCs can induce the osteogenic differentiation of BMSCs; however, intervention with high concentrations of GC may lead to changes in aging and autophagy in certain cell types.

METHODS

We generated an ONFH mouse model by injecting C57BL/6 J mice with MPS. BMSCs were harvested from the femora and tibiae of mice and were analyzed for osteogenesis, adipogenesis, senescence, and cell proliferation. In vitro, BMSCs were treated with different concentrations of GC for 48 h, followed by functional analyses to identify differentially expressed genes (DEGs) associated with ONFH. Additionally, various bioinformatics analyses were performed to identify differentially expressed genes in ONFH.

RESULTS

BMSCs from ONFH mice showed signs of aging, as indicated by increased SA-β-gal positive cells (4.4-fold) and upregulated p53 (2.6-fold) and p21 (2.0-fold) protein expression. It is also accompanied by changes in osteogenic/lipogenic differentiation ability. Bioinformatics analysis further verified these findings. High-dose GC stimulation significantly induced cellular senescence of BMSCs, as indicated by an increase in SA-β-gal positive cells (6.2-fold) and a decrease in autophagy levels. GC stimulation changes the differentiation fate of BMSCs.

CONCLUSIONS

Our results indicated that GC-induced ONFH was associated with changes in aging and autophagy in BMSCs. GC not only directly affected the osteogenic differentiation of BMSCs but also indirectly affected their differentiation fate through aging and autophagy changes.

[Clinical study of double-channel core decompression combined with medullary cavity irrigation for non-traumatic osteonecrosis of femoral head]

Objective

To compare the effects of double-channel core decompression (CD) combined with medullary cavity irrigation with those of simple CD on progression of collapse and clinical outcomes in non-traumatic osteonecrosis of the femoral head (ONFH).

Methods

A retrospective analysis was conducted on the clinical data of 19 patients (30 hips) with non-traumatic ONFH who underwent double-channel CD combined with medullary cavity irrigation and admitted between January 2024 and October 2024 (CD+irrigation group). According to a 1: 2 ratio, 54 patients (60 hips) who underwent simple CD and were matched in terms of age, gender, and body mass index (BMI) were included as the control (CD group). There was no significant difference in baseline data such as age, gender, BMI, affected side, ONFH type, preoperative Association Research Circulation Osseous (ARCO) stage, bone marrow edema stage, visual analogue scale (VAS) score for pain, and Harris score between the two groups ( P>0.05). The postoperative discharge time and occurrence of complications were recorded for both groups. The VAS scores before operation and at discharge after operation were compared, and the differences between pre- and post-operation (change values) were calculated for intergroup comparison. The Harris scores before operation and at discharge and 3 months after operation were also compared. During follow-up, X-ray film, CT, and MRI were performed for reexamination. The ARCO stage and bone marrow edema stage were evaluated at 3 months after operation and compared with those before operation to determine whether there was radiological progression or relief.

Results

All incisions in both groups healed by first intention after operation, with no infection, femoral neck fracture, or other operation-related complications. All patients were followed up, and the follow-up time of the CD+irrigation group was (146.8±27.7) days, and that of the CD group was (164.3±48.2) days; there was no significant difference between the two groups ( t=1.840, P=0.069). There was no significant difference in the length of hospital stay between the two groups ( P>0.05). At discharge after operation, the VAS score of the CD+irrigation group was significantly lower than that of the CD group ( P<0.05), and the change value was significantly higher than that of the CD group ( P<0.05). The Harris scores at discharge and 3 months after operation in the CD+irrigation group were significantly higher than those in the CD group ( P<0.05). The Harris score gradually increased with time, and the differences between different time points were significant ( P<0.05). Radiological reexamination showed that there was no significant difference in the ARCO stage and the incidence of radiological progression between the two groups at 3 months after operation ( P>0.05); however, the bone marrow edema stage and the degree of bone marrow edema relief in the CD+irrigation group were better than those in the CD group, with significant differences ( P<0.05).

Conclusion

Double-channel CD combined with medullary cavity irrigation can significantly alleviate hip joint pain and improve joint function in patients with non-traumatic ONFH, reduce the degree of bone marrow edema in the femoral head, and delay the progression of ONFH.

Efficacy and safety of platelet-rich plasma combined with core decompression and enhanced bone grafting versus core decompression with enhanced bone grafting alone in treating femoral head necrosis: a systematic review and meta-analysis

BACKGROUND

The efficacy and safety of platelet-rich plasma (PRP) combined with core decompression (CD)-enhanced bone grafting for the treatment of osteonecrosis of the femoral head remains controversial. This study aimed to conduct a systematic review and meta-analysis of the efficacy and safety of PRP combined with CD-enhanced bone grafting for treating osteonecrosis of the femoral head and to compare this method with CD-combined bone grafting as a way to provide theoretical bases for future clinical treatments and research.

OBJECTIVE

This study aimed to assess the improved efficacy and safety of core decompression combined with platelet-rich plasma-enhanced bone grafting for osteonecrosis of the femoral head compared to core decompression-enhanced bone grafting.

METHOD

We systematically searched several databases for randomised controlled trials comparing bone graft and core decompression with or without PRP, including 16 studies involving 999 subjects and 1139 hip cases. This meta-analysis followed the Preferred Reporting Items (PRISMA) guidelines. The study is registered with PROSPERO under code CRD42024557968.

RESULT

16 articles involving 999 patients (1139 hips) were included in this study. Pooled analyses demonstrated that when core decompression-enhanced bone grafting was combined with PRP, the Harris hip score (mean difference [MD]: 5.26, 95% Cl:4.81-5.71; P < 0.00001), visual analog scale (MD: -0.74, 95% Cl:-0.99 - -0.49; P < 0.00001) and reduction in the need for THA: (risk ratio [RR]: 0.29; 95% Cl:0.16-0.53; P < 0.0001) were superior to core decompression-enhanced bone grafting alone. Furthermore, a pooled analysis confirmed the safety of PRP [RR:0.33; 95% Cl:0.13-0.83; P = 0.02]. All these results were statistically significant.

CONCLUSION

Compared to CD-enhanced bone grafting, the combination of PRP appears to yield superior therapeutic outcomes in restoring hip function, alleviating pain, preventing THA, and ensuring postoperative safety. Moreover, we require a higher level of randomised controlled trials to evaluate its efficacy and safety.

Differential risk of autoimmune disorders in non-traumatic osteonecrosis: clue to pathogenesis

INTRODUCTION

Non-traumatic osteonecrosis is a frequent complication in patients with autoimmune disorders, though its prevalence varies markedly depending upon the type of disorder. Understanding the causes of this difference can help uncover the underlying pathophysiology of osteonecrosis and guide the development of effective preventive and therapeutic strategies.

AREAS COVERED

In this perspective study, we reviewed available databases, including PubMed, Cochrane Library, Scopus, and Web of Science, to explore why the risk of osteonecrosis varies among different autoimmune disorders. Is this variation primarily due to the disease's pathophysiology, the use of medications such as corticosteroids, or a combination of both? If both factors are involved, what is the extent of each contribution in this context?

EXPERT OPINION

Non-traumatic osteonecrosis is often induced by an interaction between disease pathophysiology and corticosteroid use. In patients with different autoimmune disorders but an identical history of corticosteroid use, the risk of osteonecrosis is influenced by how the underlying pathophysiology compromises bone health. In autoimmune disorders with multiple adverse effects on bone, such as SLE (systemic lupus erythematosus), there is a much higher risk of osteonecrosis compared to disorders with minimal impact on bone health, such as celiac disease and MS (multiple sclerosis).

Advances in copper-containing biomaterials for managing bone-related diseases

Bone-related diseases pose a major challenge in contemporary society, with significant implications for both health and economy. Copper, a vital trace metal in the human body, facilitates a wide range of physiological processes by being crucial for the function of proteins and enzymes. Numerous studies have validated copper's role in bone regeneration and protection, particularly in the development and expansion of bone collagen. Owing to copper's numerous biological advantages, an increasing number of scientists are endeavoring to fabricate novel, multifunctional copper-containing biomaterials as an effective treatment strategy for bone disorders. This review integrates the current understanding regarding the biological functions of copper from the molecular and cellular levels, highlighting its potential for bone regeneration and protection. It also reviews the novel fabrication techniques for developing copper-containing biomaterials, including copper-modified metals, calcium phosphate bioceramics, bioactive glasses, bone cements, hydrogels and biocomposites. The fabrication strategies and various applications of these biomaterials in addressing conditions such as fractures, bone tumors, osteomyelitis, osteoporosis, osteoarthritis and osteonecrosis are carefully elaborated. Moreover, the long-term safety and toxicity assessments of these biomaterials are also presented. Finally, the review addresses current challenges and future prospects, in particular the regulatory challenges and safety issues faced in clinical implementation, with the aim of guiding the strategic design of multifunctional copper-based biomaterials to effectively manage bone-related diseases.

Relationship between anterior or posterior femoral head necrosis and collapse based on MRI-defined key necrotic layer sets

BACKGROUND

Current clinical studies on femoral head necrotic lesions primarily focus on the medial and lateral regions, while detailed MRI-based methods to evaluate the relationship between anterior or posterior necrosis and collapse remain lacking.

OBJECTIVE

By defining the anterior and posterior positions of the femoral head in MRI, a method was proposed for rapid clinical prognosis assessment of femoral head necrosis based on necrotic location.

METOHD

A retrospective analysis was conducted on TSE sequence T1W1 coronal plane images from 200 cases of femoral head necrosis. The frequency of necrotic lesions appearing on each MRI layer was statistically analyzed to construct a high-frequency necrotic layer set. Among these cases, 100 hips were randomly selected, and the relationship between femoral head collapse at one-year follow-up and different high-frequency necrotic layer sets was analyzed to identify the key necrotic layer set. Based on this, the anterior and posterior regions of the femoral head were defined on MRI. The remaining 100 hips were used as a validation set to assess the impact of anterior or posterior necrosis of the femoral head, as defined by this method, on collapse.

RESULTS

In this study, a total of eight high-frequency necrotic lesion layer sets (S1-S8) were constructed based on MRI data. Among them, S3 (L1 + L2 + L0 + L3) showed the strongest correlation with femoral head collapse, with an AUC of 0.662. Therefore, S3 was defined as the anterior side of the femoral head. Analysis of the validation set revealed that, using this method, the probability of femoral head collapse was 11.4 times higher when necrotic lesions appeared on the anterior side compared to the absence of necrosis on the anterior side.

CONCLUSION

In MRI, the anterior side of the femoral head corresponds to the S3 region, where necrosis increases the risk of collapse by 11.4 times.

Personalizing core decompression grafting technique for osteonecrosis of the femoral head: calculating the volume of bone resected and adjunct volume required to fill the defect

BACKGROUND

Osteonecrosis of the femoral head can be a debilitating disease leading to collapse of the femoral head and the subsequent need for a hip arthroplasty. Core decompression has emerged as a leading treatment to prevent collapse. Adjunctive therapies, such as bone graft, bone marrow aspirate concentrates, or synthetic bone substitutes are utilized to promote native bone regeneration. Determining the amount of bone resected and the volume of adjunct required is challenging, especially with newer minimally invasive reamers. Under- or over-filling the defect may impact progression of the disease or cause morbidity.

SURGICAL TECHNIQUE

We introduce a mathematical method to be utilized intraoperatively to calculate the volume of bone resected during core decompression with an expandable reamer. This method approximates the core decompression defect as two cylinders using measurements that can be easily taken during the procedure and can be adapted for use with any of the expandable reamer systems available. Using this technique, surgeons can calculate the size of the defect created, which can be used to personalize the amount of adjunct delivered to each patient.

CONCLUSIONS

When adjunctive therapies are used with core decompression to treat ONFH, care must be taken when filling the core decompression defect to avoid under- or over-filling the defect, potentially increasing the risk of complications or reducing the efficacy of the procedure. We provide a simple worksheet that can be used by surgeons to help determine how much adjunct should be used.

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.

Leveraging AI models for lesion detection in osteonecrosis of the femoral head and T1-weighted MRI generation from radiographs

This study emphasizes the importance of early detection of osteonecrosis of the femoral head (ONFH) in young patients on long-term glucocorticoid therapy, including those with acute lymphoblastic leukemia, lupus, and other diagnoses. While X-ray and magnetic resonance imaging (MRI) are standard imaging methods for staging ONFH, MRI can be costly and time-consuming. The research focuses on utilizing artificial intelligence (AI) to enhance the evaluation of radiographic images for ONFH detection. The study involved analyzing X-ray and MRI from 102 control hips and 104 ONFH-affected hips at Association Research Circulation Osseous (ARCO) Stage II and IIIa. We employed transfer learning with the YOLOv8 model for object detection, using 80% of the data for training and 20% for validation, then assessed detection accuracy through mean average precision (mAP) and a precision-recall curve. Additionally, AI generated synthetic MRI (sMRI) from X-ray images using a Generative Adversarial Network (GAN) and evaluated their similarity to original MRI. Results showed that the mAP for ONFH detection was 0.923 for the YOLOv8n model and 0.951 for YOLOv8x. The GAN-generated sMRI exhibited lower image quality compared with originals but maintained potential for lesion assessment. Intrarater reliability among evaluators was high. The findings indicate that AI techniques, particularly YOLOv8 for object detection and GAN for image generation, can effectively assist in ONFH screening, despite some limitations in the generated MRI quality.

Short-term outcomes of AVN CAGE implantation for early-stage osteonecrosis of the femoral head

PURPOSE

Considering the low survival rate for the numerous hip-preserving procedures developed for treating early-stage osteonecrosis of the femoral head (ONFH), this study aimed to evaluate short-term clinical outcomes following avascular necrosis (AVN) CAGE implantation.

METHODS

58 hips with early-stage ONFH (44 with Association Research Circulation Osseous [ARCO] stage 2 and 14 with stage 3A) treated with the AVN CAGE between August 2018 and December 2021 were included. The survival rates were analysed using radiographic progression and conversion to subsequent total hip arthroplasty (THA) as endpoints.

RESULTS

The mean follow-up period was 22.2 ± 8.2 months. 11 hips progressed to ARCO stage 3B/4, and 6 underwent THA. The estimated 2-year radiographic survival rates were 89.1% and 59.0% for patients with ARCO stages 2 and 3A, respectively. The estimated 2-year radiographic survival rates were 92.9% and 76.3% for Japanese Investigation Committee type B/C1 and C2, respectively. The overall estimated 2-year THA-free survival rate was 88.9%. Advanced disease stage and a large necrotic area were independent risk factors for radiographic progression.

CONCLUSIONS

AVN CAGE combined with standard core decompression was a promising hip-preserving option for patients with no signs of collapse, small necrotic areas, or medially located necrotic locations.

Hip joint-preserving strategies for treating osteonecrosis of the femoral head: From nonoperative to operative procedures

Osteonecrosis of the femoral head (ONFH) has an exceedingly high prevalence and disability rate, causing a tremendous socioeconomic burden. The prevalence of ONFH is increasing, while the population of the patients with ONFH is becoming younger. Once the femoral head collapses, treatment becomes difficult and often requires a hip joint replacement, which is not favorable for young patients. Therefore, hip joint-preserving treatments at an early stage of ONFH are particularly important. This study provides a comprehensive review on hip-preserving strategies for treating ONFH, including nonoperative treatments (e.g., protective weight bearing, hyperbaric oxygen, pulsed electromagnetic, extracorporeal shockwave, bisphosphonate, anticoagulants, hypolipidemics, vasodilators, and traditional Chinese medicine) and operative treatments (e.g., core decompression, osteotomy, bone grafting, mesenchymal stem cell transplantation, tantalum rods, and tissue engineering). Nonoperative treatments aim to slow down the progression of the disease and delay the need for joint replacement; however, they usually cannot effectively prevent the progression of the disease, except in cases of small necrosis areas (<10 %). Additionally, nonoperative treatments have unclear mechanisms that require further investigation. In contrast, operative treatments may stop the negative outcomes of necrosis and therefore appear to be more promising. Currently, an emerging area in operative treatments is regenerative medicine, which could promote the generation of bone tissues and blood vessels and restore hip joint function to pre-necrotic levels as much as possible. This review seeks to not only provide an important reference for clinicians when choosing appropriate strategies for treating ONFH but also offer certain guidance for future basic research in developing ONFH treatments.

The translational potential of this article

The incidence of ONFH is increasing, and patients are becoming younger on average. Therefore, the development of hip joint-preserving strategies to treat ONFH at earlier stages is urgently needed, particularly for young patients. However, a comprehensive review is lacking regarding the currently-available hip joint-preserving strategies and their effectiveness. This study is motivated to fill this gap and serve as an important reference for clinicians in choosing appropriate strategies to treat ONFH.

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.

Jack Surgery: Reconstructing Collapsed Femoral Head in Association Research Circulation Osseous Stage III Osteonecrosis: A Series of 13 Cases

OBJECTIVE

According to Association Research Circulation Osseous (ARCO) staging, patients with ARCO III osteonecrosis of femoral head (ONFH) have joint pain and dysfunction due to the collapse of femoral head. Current hip preservation surgeries are not satisfying in the treatment of ARCO III ONFH according to the long-term follow-up. In our practice, we focused on reconstructing femoral head by restoring the round shape of femoral head and subsequently preventing the development of hip arthritis. To lift the collapsed femoral head and postpone the potential total hip arthroplasty, we practiced Jack surgery, combining surgical hip dislocation, removal of necrotic bone, impaction bone grafting, and lifting the cartilage of femoral head.

METHODS

From February 2019 to July 2022, 13 patients (15 hips) who received Jack surgery in the research center were included in this retrospective study. Follow-up was conducted every 3 months after surgery for imaging and clinical evaluation. The differences between visual analogue scale (VAS) and Harris hip score (HSS) before and after surgery were compared to observe whether the femoral head collapsed and whether osteotomy healed after surgery. Severe collapse of the femoral head ( > 2 mm) or receiving total hip arthroplasty (THA) was defined as failure of hip preservation therapy. An Independent sample t-test was used to compare the data, and the chi-square test was used for categorical data.

RESULTS

All the 13 patients successfully completed the surgery and were followed up. The average time of follow-up was 36.46 ± 16.87 months (ranging from 14 to 66 months). HSS was assessed 12 months after surgery: excellent in 1 patient with 1 hip; good in 9 patients with 11 hips; modest in 3 patients with 3 hips. To the last follow-up, the VAS scores decreased from 6.17 ± 1.02 to 2.08 ± 0.90 (p < 0.001), HSS increased from 46.69 ± 4.15 to 89.77 ± 2.86 (p < 0.001). No deep infection, fracture, osteotomy nonunion, nerve injury, deep vein thrombosis, pulmonary embolism, or other complications occurred.

CONCLUSION

For young patients with ONFH of ACRO III, this surgical technique can effectively restore the original shape of the femoral head and achieve satisfactory hip function in the short term. The mechanism is similar to jacking the roof of a house; thus, we named it "Jack surgery".

Therapeutic effect of low-dose BMSCs-Loaded 3D microscaffold on early osteonecrosis of the femoral head

The early treatment of Osteonecrosis of Femoral Head (ONFH) remains a clinical challenge. Conventional Bone Marrow Mesenchymal Stem Cell (BMSC) injection methods often result in unsatisfactory outcomes due to mechanical cell damage, low cell survival and retention rates, inadequate cell matrix accumulation, and poor intercellular interaction. In this study, we employed a novel cell carrier material termed "3D Microscaffold" to deliver BMSCs, addressing these issues and enhancing the therapeutic effects of cell therapy for ONFH. We injected 3D microscaffold loaded with low-dose BMSCs or free high-dose BMSCs into the femoral heads of ONFH rats and assessed therapeutic effects using imaging, serology, histology, and immunohistochemistry. To understand the mechanism of efficacy, we established a co-culture model of human osteoblasts and BMSCs, followed by cell proliferation and activity detection, flow cytometry analysis, Quantitative RT-PCR, and Western blotting. Additionally, RNA sequencing was performed on femoral head tissues. Results showed that the 3D microscaffold with low-dose BMSCs had a therapeutic effect comparable to high-dose free BMSCs. Osteoblasts in the 3D microscaffold group exhibited superior phenotypes compared to the non-3D microscaffold group. Furthermore, we have, for the first time, preliminarily validated that the low-dose BMSCs-loaded 3D microscaffolds may promote the repair of femoral head necrosis through the synergistic action of the MAPK and Hippo signaling pathways.

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.

Biomechanical and clinically controlled study of different fenestration positions in vascularized iliac bone flaps for treating femoral head necrosis

BACKGROUND

No appropriate studies have been conducted that compare the biomechanical properties of different fenestration positions in deep circumflex iliac artery (DCIA)-vascularized iliac bone grafts for femoral head necrosis (ONFH) treatment. In this study, we aimed to explore the fenestration locations of DCIA-vascularized iliac grafting in ONFH treatment using FEA and clinical retrospective analysis.

METHODS

We simulated an iliac bone flap transplantation with a vascularized tip by finite element analysis (FEA). Patients were divided into four groups using different femur fenestration positions as follows: center-window group (C-group), superior-window group (S-group), medial-window group (M-group), and inferior-window group (I-group). In this study, we primarily observed the maximum femoral stress at different healing degrees (0, 25, 50, 75, and 100%). We retrospectively analyzed the changes in the postoperative Harris scores (HHS) and the imaging of 16 patients with iliac flaps for ONFH (11 and 5 cases in the center and other-positioned groups, respectively) at the final follow-up visit.

RESULTS

The FEA results showed that the peak von Mises stresses in the four groups at the time of complete healing were in the following order: group C (20.28 MPa) < group I (20.33 MPa) < group M (20.92 MPa) < group S (22.00 MPa). A clinical retrospective study following a comparison of the two groups found that the mean improvement in HHS was 18.00 ± 12.38 in the center-window group and 13.60 ± 25.55 in the other groups. However, no significant difference was observed in the rate of collapse (36.37 vs. 40.00%) or changes in the HHS between the two groups.

CONCLUSION

A fenestration at the center of the femoral neck resulted in improved biomechanical gain and clinical outcomes.

TRIAL REGISTRATION

approval was granted by the Ethics Committee (II202418102).

A radiomics and deep learning nomogram developed and validated for predicting no-collapse survival in patients with osteonecrosis after multiple drilling

PURPOSE

Identifying patients who may benefit from multiple drilling are crucial. Hence, the purpose of the study is to utilize radiomics and deep learning for predicting no-collapse survival in patients with femoral head osteonecrosis.

METHODS

Patients who underwent multiple drilling were enrolled. Radiomics and deep learning features were extracted from pelvic radiographs and selected by LASSO-COX regression, radiomics and DL signature were then built. The clinical variables were selected through univariate and multivariate Cox regression analysis, and the clinical, radiomics, DL and DLRC model were constructed. Model performance was evaluated using the concordance index (C-index), area under the receiver operating characteristic curve (AUC), net reclassification index (NRI), integrated discrimination improvement (IDI), calibration curves, and Decision Curve Analysis (DCA).

RESULTS

A total of 144 patients (212 hips) were included in the study. ARCO classification, bone marrow edema, and combined necrotic angle were identified as independent risk factors for collapse. The DLRC model exhibited superior discrimination ability with higher C-index of 0.78 (95%CI: 0.73-0.84) and AUC values (0.83 and 0.87) than other models. The DLRC model demonstrated superior predictive performance with a higher C-index of 0.78 (95% CI: 0.73-0.84) and area under the curve (AUC) values of 0.83 for 3-year survival and 0.87 for 5-year survival, outperforming other models. The DLRC model also exhibited favorable calibration and clinical utility, with Kaplan-Meier survival curves revealing significant differences in survival rates between high-risk and low-risk cohorts.

CONCLUSION

This study introduces a novel approach that integrates radiomics and deep learning techniques and demonstrates superior predictive performance for no-collapse survival after multiple drilling. It offers enhanced discrimination ability, favorable calibration, and strong clinical utility, making it a valuable tool for stratifying patients into high-risk and low-risk groups. The model has the potential to provide personalized risk assessment, guiding treatment decisions and improving outcomes in patients with osteonecrosis of the femoral head.

The efficacy of core decompression combined with regenerative therapy in early femoral head necrosis: a systematic review and meta-analysis involving 954 subjects

Background

The debate continues on whether combining core decompression (CD) with regenerative therapy provides a more effective treatment for early femoral head necrosis than CD alone. This systematic review and meta-analysis endeavored to assess its efficacy.

Methods

We systematically searched PubMed, Web of Science, and Cochrane Library through July 2024 for RCTs and cohort studies evaluating the impact of core decompression (CD) with regenerative therapy versus CD alone in early-stage osteonecrosis (ARCO I, II or IIIa or Ficat I or II) of the femoral head (ONFH). Bias was evaluated using the Cochrane ROB 2.0 for RCTs and the Newcastle-Ottawa Scale (NOS) for cohort studies. The primary outcome was disease progression, measured by the incidence of staging advancement and total hip arthroplasty (THA) conversion. Clinical outcomes, including VAS, HHS, WOMAC, and Lequesne index, were secondary measures. Subgroup analyses were performed for variables such as age, BMI, follow-up period, and dosage in the bone marrow aspirate concentrate (BMAC) group, with results depicted in forest plots.

Results

This study represented a total of seven RCTs (mean follow-up time 36.57 months) and eight cohort trials (mean follow-up time 74.18 months) involving 954 hips. CD, when combined with agents, exhibited considerably enhanced efficacy over CD alone (risk ratio (RR) = 0.55 (95% CI 0.39-0.77), p < 0.001, I 2 = 54%) and 0.59 (95% CI 0.43-0.81), p = 0.001, I 2 = 51%), respectively). However, a significant difference was exclusive to the CD combined with BMAC group in terms of stage progression outcomes (stage progression, RR = 0.47 (95% CI 0.28-0.78), p = 0.004, I 2 = 67%); THA conversions, RR = 0.41 (95% CI 0.32-0.52), p < 0.001, I 2 = 43%). Secondary outcomes (VAS, HHS, WOMAC score and Lequesne index) showed improved results when CD was combined with other regenerative agents, such as bone mesenchymal stem cells (BMSCs) and bone morphogenetic proteins (BMPs), etc. In the reported data, the regenerative group demonstrated significantly higher rates of subjective improvement in pain and functional outcomes compared to those in the CD group (71.74% (66/92) vs. 56.38% (53/94). Subgroup analysis revealed superior outcomes in the low-dose (less than 20 mL) BMAC group and patients aged under 40 years old in stage progression rate and THA conversion rate.

Conclusion

CD, when combined with regenerative therapy, can diminish hip pain and enhance functionality, but its ability to slow disease progression remains uncertain. BMAC presents a more substantiated efficacy evidence than other agents, with low-doses of BMAC in patients under 40 years potentially slowing ONFH progression. Nonetheless, the high heterogeneity and relatively short follow-up time of these studies make it difficult to draw accurate conclusions, which necessitates verification through future trials comparing CD versus CD combined with regenerative therapy, with a focus on extended follow-up periods.

Systematic Review Registration

identifier CRD42023467873.

Efficacy of small-diameter core decompression with platelet-rich plasma in early osteonecrosis of the femoral head: a retrospective study

BACKGROUND

Osteonecrosis of the femoral head (ONFH) is a challenging condition, primarily affecting young and middle-aged individuals, which results in hip dysfunction and, ultimately, femoral head collapse. However, the comparative effectiveness of joint-preserving procedures, particularly in the early stages of ONFH (ARCO stage I or II), remains inconclusive. This study aims to evaluate the efficacy of a novel technique called small-diameter core decompression (CD) combined with platelet-rich plasma (PRP), for the treatment of early-stage ONFH.

METHODS

Clinical data of 40 patients (51 hips) with pre-collapse stage ONFH were retrospectively analyzed. Nineteen patients (23 hips) underwent small-diameter CD + PRP (group A) and 21 patients (28 hips) received conventional CD (group B) and follow-up was conducted every 3 months. Hip radiographs (X-rays and MRI) were evaluated using various ONFH staging systems (Preserved Angles, ARCO, JIC, and CHFJ stages). X-rays were performed at each follow-up to assess femoral head collapse and the rate of total hip arthroplasty (THA). Additionally, the Visual Analogue Scale (VAS), Harris Hip Score (HHS), Charnley score, SF-36, Athens Insomnia Scale (AIS), and State-Trait Anxiety Inventory (STAI) were used to evaluate hip pain, function, quality of life, and psychological status. These assessments were conducted both preoperatively and at each follow-up visit.

RESULTS

The mean follow-up duration in Group A was 11.57 months, with a femoral head survivorship of 82.61%. One hip underwent THA 14 months after the novel procedure. In Group B, with an average follow-up period of 11.32 months, femoral head survivorship was 60.71% (p = 0.111), and 2 hips required THA (p = 0.999). At the final follow-up, the VAS, stiffness, HHS and Charnley scores of Group A showed significant improvements compared to those in Group B. Quality of life, anxiety and insomnia were also significantly improved in the Group A compared to Group B.

CONCLUSION

The application of PRP following CD results in significant pain relief, improved short-term functional outcomes, and enhanced quality of life compared to CD alone. However, whether it hinders disease progression in early ONFH and reduces the conversion rate to THA and femoral head collapse remains uncertain. Further research with larger sample sizes and extended follow-up is needed to validate these preliminary findings.

Extracorporeal shock wave therapy with imaging examination for early osteonecrosis of the femoral head: a systematic review

BACKGROUND

Extracorporeal shockwave therapy (ESWT) is a traditional noninvasive therapy to treat osteonecrosis of the femur head (ONFH). This systematic review aims to investigate whether ESWT can improve the clinical function of ONFH and whether differences in improvement can be observed in radiographic outcomes.

MATERIALS AND METHODS

Two authors independently searched PubMed, Embase, Cochrane Library, and Web of Science for English articles until 21 October 2023. After screening and reading the literature, the two authors independently used corresponding scales to evaluate the quality of the included articles and extracted data. The key data extracted included the Harris Hip Score (HHS), Visual Analog Scale (VAS), changes in lesion size, the change in the Association Research Circulation Osseous (ARCO) stage, and bone marrow edema (BME) stage.

RESULTS

Nine articles included 468 males and 248 females. The average age was 43.29 years and the mean follow-up time was 15.19 months. After receiving ESWT, five studies involving 146 hips showed a higher HHS (MD=-33.38; 95% CI: -46.31, -20.45), and the difference was statistically significant ( P <0.00001). The average VAS before treatment was above 5, but it dropped to 1.2 after ESWT (MD=4.64; 95% CI: 3.63-5.64), and the difference was statistically significant ( P <0.00001). Three studies found no significant differences in the areas of femoral head necrosis before and after treatment with ESWT(MD=9.66; 95% CI: -0.36, 19.67; P =0.06; I2 =84%). Two articles showed that the use of ESWT had no significant effect on the change in the ARCO stage (MD=1.11; 95% CI: 0.76-1.62; P =0.60; I2 =0%). Three studies indicated that using ESWT could improve the BME symptom in the early stage of ONFH (MD=4.35; 95% CI: 1.32-14.37; P =0.02; I2 =62%).

CONCLUSION

Based on the current evidence, ESWT shows promise as a therapy to enhance hip function and alleviate pain in the early stage of ONFH. With the advancement of more precise imaging techniques, ESWT can potentially reduce the area affected by ONFH. However, such reduction was not found to be statistically significant at the imaging level. Additionally, ESWT could improve symptoms of BME in the early stage. However, no significant change in ARCO grade was observed with ESWT treatment.

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.

Application of additive manufacturing TaBw01 porous tantalum rod in ARCO stage II osteonecrosis of the femoral head

PURPOSE

This study aims to investigate the suitable surgical strategies for applying TaBw01 porous tantalum rod across different stages of osteonecrosis of the femoral head (ONFH).

METHODS

TaBw01 tantalum rods were fabricated using type FTaY-1 tantalum powder via the foam impregnation-sintering method. Mechanical testing with the Instron 8801 universal testing machine and finite element analysis (FEA) assessed single tantalum rod implantation and impaction bone grafting combined with rod implantation. A total of 86 osteonecrosis of the femoral head (ONFH) patients (94 hips) were treated: the experimental group (45 patients, 50 hips) underwent surgical hip dislocation (SHD) with impaction bone grafting and tantalum rod implantation, while the control group (41 patients, 44 hips) received single rod implantation. Primary failure criteria included femoral head collapse (≥ 2 mm) or total hip arthroplasty. Patient-reported outcomes (PROs), including Harris Hip Score (HHS), Visual Analog Score (VAS), Hip Outcome Score Activities of Daily Living Subscale (HOS-ADL), and Hip Outcome Score Sport-Specific Subscale (HOS-SSS), were analyzed based on Minimum Clinically Important Difference (MCID).

RESULTS

FEA confirmed stresses below the material's yield and compressive strength. At 3 years, survival rates for ARCO (Association Research Circulation Osseous) stage IIb and IIc were higher in the experimental group (100%, 80.38%) than the control group, while stage IIa survival was 100% in the control group. The experimental group also had higher MCID attainment for HHS, HOS-ADL, and HOS-SSS.

CONCLUSIONS

Compared with single TaBw01 implantation, impaction bone grafting combined with TaBw01 implantation via SHD demonstrated superior outcomes for ARCO stage IIb and IIc, with a minimum 2-year follow-up. while single TaBw01 implantation may be more suitable for stage IIa. This study emphasizes the importance of combining biological and biomechanical reconstruction in ONFH treatment.

Techniques of core decompression in the treatment of idiopathic avascular necrosis of the femoral head

Core decompression was developed as a joint-preserving procedure for patients with early-stage osteonecrosis of the femoral head. Previous studies indicated a high success rate that outperforms nonoperative management of pre-collapse hips. The traditional single-tunnel core decompression technique uses a cannulated drill bit inserted into the lateral cortex of the proximal femur. Multiple small drilling was introduced to decrease the risk of fracture through a less invasive technique. Adjunctive therapeutics such as tantalum rods, bone-grafting, orthobiologic (e,g, bone marrow aspirate concentrate, mesenchymal stem cells, platelet-rich plasma, and human umbilical cord mesenchymal stem cell extracts) as well as electric stimulation have all been studied. No consensus regarding the ideal treatment has been reached. This review analyzes the advantages and disadvantages of current core decompression techniques to provide orthopaedic surgeons with direction in managing patients with avascular necrosis of the femoral head.

Safety and efficacy of orthopedic robots in total hip arthroplasty: a network meta-analysis and systematic review

BACKGROUND

With the increasing demand for total hip arthroplasty (THA) and the inevitable trend of orthopedic robots and artificial intelligence in the future, it is necessary to explore the safety and effectiveness of orthopedic robots in THA. Currently, most orthopedic robots are in the early stages of development, and evaluating their clinical efficacy can assist in making informed decisions for practical use.

OBJECTIVE

To explore the advantages of 7 types of robot-assisted THA with respect to 5 indicators.

METHODS

Literature from databases such as CNKI, PubMed, and Web of Science was retrieved up to July 17, 2024. Literature evaluation was conducted via Review Manager 5.4, and a network meta-analysis was performed via RStudio (version 4.4.1).

RESULTS

A total of 17 studies involving 1741 patients were included. In direct comparisons, the operation time was longer for MAKO (MD = 19; CI = 6.7, 31), TRex (MD = 37, CI = 20, 54) and YUANHUA (MD = 35, CI = 4.2, 66) than for C-THA. The leg length discrepancy (LLD) was smaller for TRex (MD = -3.4, CI = -6.6, -0.36) and RO (MD = -4.3, CI = -8.7, -0.064) than for C-THA. In the comprehensive best probability ranking, operation time [C-THA (96%) > TJ (68%) > RO (53.2%) > MAKO (53%) > LA (45%) > YU (21%) > TR (13%)], blood loss [TJ (89%) > C-THA (50%) > LA (49%) > YU (42%) > MAKO (20%)], LLD [RO (83%) > TR (75%) > MAKO (61%) > TJ (51%) > YU (43%) > JJ (40%) > C-THA (24%) > LA (22%)], HHS [RO (65%) > C-THA (55%) > LA (51%) > TR (50%) > JJ (48%) > YU (46%) > MAKO (37%)], and infection [TJ (77%) > C-THA (67%) > MAKO (44%) > RO (10%)].

CONCLUSION

Each of the seven types of RA-THA and C-THA has its own advantages, with TJ and RO RA-THA being slightly more prominent. Overall, in terms of safety and effectiveness, RA-THA is generally superior to C-THA, although further development is still needed.

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.

Arthroscopy-Assisted Core Decompression and Bone Grafting for Avascular Necrosis of the Hip

Although specific techniques vary, core decompression is generally accepted as the treatment of choice for precollapse avascular necrosis (AVN) of the hip to delay or prevent progression of the disease. This can be combined with hip arthroscopy to allow visual assessment of the femoral head as well as treatment of intra-articular pathologies, which may contribute to pain and joint degeneration. We describe a technique of hip arthroscopy and concurrent core decompression using an expandable reamer and bone grafting for treatment of hip AVN. This allows for minimally invasive treatment of both bony and intra-articular soft tissue pathologies, which are often concomitantly present in hip AVN disease, while minimizing reaming of healthy femoral bone.

Pathological mechanisms and related markers of steroid-induced osteonecrosis of the femoral head

BACKGROUND

Osteonecrosis of the femoral head (ONFH) is a refractory orthopedic disease with a high disability rate. Long-term administration of steroids is the most common pathogenic factor for non-traumatic ONFH. Early diagnosis of steroid-induced osteonecrosis of the femoral head (SONFH) is difficult and mainly depends on imaging.

OBJECTIVES

The objectives of this review were to examine the pathological mechanisms of SONFH, summarize related markers of SONFH, and identify areas for future studies.

METHODS

We reviewed studies on pathological mechanisms and related markers of SONFH and discussed the relationship between them, as well as clinical applications and the outlook of potential markers.

RESULTS

The pathological mechanisms of SONFH included decreased osteogenesis, lipid accumulation, increased intraosseous pressure, and microcirculation disruption. Differential proteomics and genomics play crucial roles in the occurrence, progression, and outcome of SONFH, providing novel insights into SONFH. Additionally, the biological functions of mesenchymal stem cells (MSCs) and exosomes (Exos) in SONFH have attracted increasing attention.

CONCLUSIONS

The pathological mechanisms of SONFH are complex. The related markers mentioned in the current review can predict the occurrence and progression of SONFH, which will help provide effective early clinical prevention and treatment strategies for SONFH.

Global incidence of osteonecrosis of the femoral head after femoral neck fracture surgery in adolescents: a meta-analysis

BACKGROUND

Osteonecrosis of the femoral head (ONFH) is a significant postoperative complication following femoral neck fractures (FNFs) in adolescents, that has garnered considerable attention from researchers. Despite this interest, the incidence of ONFH in adolescents post-FNF surgery has not been extensively evaluated. To contribute to the body of research, we performed a meta-analysis utilizing articles sourced from multiple databases, with an emphasis on the rate of ONFH occurrence in young adolescents following FNF surgery.

OBJECTIVE

The purpose of this study was to investigate the incidence of ONFH after FNFs in adolescents worldwide and analyse potential risk factors affecting its occurrence to provide guidance for the treatment and rehabilitation after FNFs in adolescents and reduce the incidence of ONFH.

METHODS

A comprehensive search of medical literature databases, including MEDLINE, Web of Science, the Cochrane Library, and Embase, was conducted to identify relevant studies on ONFH and its associated risk factors after surgical treatment for FNFs in adolescents, covering the period from the establishment of the database to April 2024. Studies that did not meet the inclusion criteria were excluded. The study was conducted based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA). Literature extraction, management, and data entry were performed using Zotero 6.0 and Excel 2016. The meta-analysis was conducted using R Studio 4.2.2. Subgroup analysis, sensitivity analysis, and assessment of publication bias were performed to explore sources of heterogeneity and evaluate the reliability of the results. This study has been registered on Prospero. (registration number: CRD4202452794; date of registration: 03/04/2024) RESULTS: A total of 17 publications involving 862 patients with FNFs were included in this meta-analysis. The findings revealed that the incidence of ONFH after FNF surgery in adolescents was 24.02% [95% CI (0.2118, 0.2712)]. The included studies demonstrated good consistency, and no publication bias was observed.

CONCLUSION

This study revealed that the incidence of ONFH after FNFs in adolescents is high (24.02%). Early screening and effective treatment of postoperative patients are crucial.

Arthroscopic assisted versus open core decompression for osteonecrosis of the femoral head: A systematic review and meta-analysis

BACKGROUND

Minimally invasive treatment options for osteonecrosis of the femoral head (ONFH) have been a prominent area of research in recent years. Arthroscopic-assisted treatments have been applied in the clinical management of ONFH; however, high-quality evidence verifying their effectiveness and safety is still lacking.

OBJECTIVE

To systematically assess the clinical efficacy and safety of arthroscopic-assisted core decompression (AACD) in treating ONFH.

METHODS

A comprehensive literature search was conducted in PubMed, Web of Science, EMBASE, Cochrane Library, Chinese National Knowledge Infrastructure, China Science and Technology Journal Database, WanFang, and the Chinese BioMedical Literature Database, from inception to June 25, 2024. We identified randomized controlled trials and non-randomized controlled studies on AACD for the treatment of ONFH based on predefined inclusion and exclusion criteria. A meta-analysis was performed using Review Manager 5.4.1 and Stata 17.0 software. The analyzed outcomes included operative time, intraoperative blood loss, length of hospital stay, postoperative femoral head collapse rate, Harris hip score, and postoperative complication rate. The Grades of Recommendations, Assessment, Development, and Evaluations (GRADE) system was used to assess the quality of evidence for the outcome indicators.

RESULTS

A total of fourteen studies were included in this meta-analysis, comprising 1,063 patients-541 in the core decompression (CD) group and 522 in the AACD group. The meta-analysis revealed no significant differences between the two groups in terms of intraoperative blood loss, length of hospital stay, 12-month postoperative Harris hip score, or overall postoperative complication rate (P > 0.05). However, the AACD group had a longer operative time (MD = 31.19, 95% Cl: 5.32 to 57.07, P = 0.02) and a lower overall postoperative femoral head collapse rate (RR = 0.49, 95% Cl: 0.27 to 0.89, P = 0.02) compared with the CD group. Additionally, the AACD group showed significant improvements in Harris hip scores at 3 months (MD = 6.39, 95% Cl: 5.44 to 7.33, P < 0.00001), 6 months (MD = 7.56, 95% Cl: 6.63 to 8.49, P < 0.00001), ≥ 24 months (MD = 7.00, 95% Cl: 4.80 to 9.21, P < 0.00001), and at the last follow-up (MD = 6.89, 95% Cl: 5.30 to 8.48, P < 0.00001) compared to the CD group. The GRADE evidence assessment indicated that the overall postoperative complication rate was supported by moderate-quality evidence, while the evidence for operative time, intraoperative blood loss, postoperative femoral head collapse rate, and Harris hip score was of low quality. The evidence for length of hospital stay was deemed very low quality.

CONCLUSION

This meta-analysis suggests that AACD is an effective and safe treatment for patients with ONFH. However, due to the limited quantity and quality of the included studies, these results should be interpreted with caution. Further high-quality studies are recommended to confirm these findings.

Predicting steroid-induced osteonecrosis of the femoral head: role of lipid metabolism biomarkers and radiomics in young and middle-aged adults

BACKGROUND

Femoral head necrosis is a common orthopedic disease that results in significant physical disability in patients. Early prediction and diagnosis of steroid-induced osteonecrosis of the femoral head (SONFH) are crucial for the prevention and treatment of this condition.

METHODS

In this study, initial CT images and clinical data of patients with SONFH, admitted from January 2019 to December 2022, were collected. Patients were grouped as follows: (1) those diagnosed with SONFH at the initial diagnosis (control group), and (2) those with high-risk factors but no symptoms at first diagnosis, who developed SONFH two years later (experimental group). CT imaging histological features, clinical characteristics, and transcriptome screening for differentially expressed genes, pathway enrichment, and immune infiltration analyses were performed.

RESULTS

Significant differences were found in triglyceride (TG) levels between the training and validation groups. Age, sex, alkaline phosphatase (ALP), and hemoglobin levels differed between the training and internal validation groups, while HDL and red blood cell counts varied between the training and external validation groups. Univariate analysis showed that age, TG, HDL, and Radiomics scores influenced SONFH, while multivariate analysis revealed TG, HDL, and Radiomics scores were closely related to SONFH. Transcriptomic analysis showed associations with sphingolipid and adipocyte signaling pathways, along with immune cell involvement, linking SONFH to lipid metabolism and atherosclerosis.

CONCLUSIONS

These findings indicate a significant association between steroid-induced osteonecrosis of the femoral head and age, with TG and HDL serving as indicators of lipid metabolism closely correlated with the occurrence of SONFH. Radiomics scores were also found to correlate with SONFH occurrence, supported by transcriptomic and CT imaging findings. However, this study has limitations, including its retrospective design and a relatively limited sample size, which may impact the generalizability of the results. Further prospective studies with larger, more diverse populations are needed to validate and enhance the predictive model.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Prediction of femoral head collapse in osteonecrosis using deep learning segmentation and radiomics texture analysis of MRI

BACKGROUND

Femoral head collapse is a critical pathological change and is regarded as turning point in disease progression in osteonecrosis of the femoral head (ONFH). In this study, we aim to build an automatic femoral head collapse prediction pipeline for ONFH based on magnetic resonance imaging (MRI) radiomics.

METHODS

In the segmentation model development dataset, T1-weighted MRI of 222 hips from two hospitals were retrospectively collected and randomly split into training (n = 190) and test (n = 32) sets. In the prognosis prediction model development dataset, 206 hips were also retrospectively collected from two hospitals and divided into training set (n = 155) and external test set (n = 51) according to data source. A deep learning model for automatic lesion segmentation was trained with nnU-Net, from which three-dimensional regions of interest were segmented and a total of 107 radiomics features were extracted. After intra-class correlation coefficients screening, feature correlation coefficient screening and Least Absolute Shrinkage and Selection Operator regression feature selection, a machine learning model for ONFH prognosis prediction was trained with Logistic Regression (LR) and Light Gradient Boosting Machine (LightGBM) algorithm.

RESULTS

The segmentation model achieved an average dice similarity coefficient of 0.848 and an average 95% Hausdorff distance of 3.794 in the test set, compared to the manual segmentation results. After feature selection, nine radiomics features were included in the prognosis prediction model. External test showed that the LightGBM model exhibited acceptable predictive performance. The area under the curve (AUC) of the prediction model was 0.851 (95% CI: 0.7268-0.9752), with an accuracy of 0.765, sensitivity of 0.833, and specificity of 0.727. Decision curve analysis showed that the LightGBM model exhibited favorable clinical utility.

CONCLUSION

This study presents an automated pipeline for predicting femoral head collapse in ONFH with acceptable performance. Further research is necessary to determine the clinical applicability of this radiomics-based approach and to assess its potential to assist in treatment decision-making for ONFH.

Changes in postoperative depression and anxiety and their relationship with recovery from femoral head necrosis: A longitudinal study

BACKGROUND

Femoral head necrosis (FHN) can significantly affect patients' psychological well-being and functional outcomes. However, the long-term relationship between postoperative depression, anxiety, and functional recovery in patients with FHN remains unclear.

AIM

To investigate the dynamic changes in postoperative depression and anxiety and their relationship with functional recovery in patients with FHN for 3 years.

METHODS

Ninety-three patients with FHN who underwent surgical treatment in March 2020 to 2023 were enrolled in this longitudinal study. Depression and anxiety status were assessed using the hospital anxiety and depression scale (HADS) at baseline, 6 months, 1, 2, and 3 years postoperatively. Functional recovery was evaluated using the Harris hip score (HHS). The dynamic changes in HADS and HHS were analyzed using repeated measures ANOVA; the relationship between depression/anxiety status and functional recovery was examined using Pearson’s correlation analysis.

RESULTS

The mean HADS-depression (HADS-D) and HADS-anxiety (HADS-A) scores significantly improved over time (P < 0.001). The prevalence of depression and anxiety decreased from 36.6% and 41.9% at baseline to 10.8% and 12.9%, respectively, at 3 years postoperatively. The mean HHS increased significantly from 52.3 ± 10.5 at baseline to 88.1 ± 7.2 at 3 years postoperatively (P < 0.001). Significant negative correlations were found between HADS-D/HADS-A scores and HHS at all time points (P < 0.05).

CONCLUSION

The severity of depression and anxiety negatively correlated with functional recovery, highlighting the importance of psychological interventions in the management of patients with FHN.

Preliminary study of the role of histone deacetylase (HDAC) in steroid-induced avascular necrosis of the femoral head induced by BMSC adipogenic differentiation

Our previous research revealed a close association between the acetylation of peroxisome proliferator-activated receptor γ (PPARγ) histone H3K27 and the adipogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). We preliminarily explored the epigenetic mechanism of steroid-induced avascular necrosis of the femoral head (SANFH) development, but the specific histone deacetylase (HDAC) involved in this regulatory process remains unknown. In this study, we combined cell, animal, and clinical specimen experiments to screen for specific HDAC genes that could regulate BMSC adipogenic differentiation and to explore their roles. The results showed that dexamethasone (DEX) significantly exacerbated the imbalance between the adipogenic and osteogenic differentiation of BMSCs, and there were differences in HDAC expression in the adipogenic differentiation cell models, with histone deacetylase 10 (HDAC10) showing the most significant decrease in expression. Subsequent use of a chromatin immunoprecipitation assay kit and quantitative polymerase chain reaction (ChIP‒qPCR) revealed a decrease in HDAC10 expression at predicted potential sites within the PPARγ promoter, indicating a significant decrease in HDAC10 enrichment in the PPARγ promoter region of BMSCs, thereby promoting sustained PPARγ expression. Additionally, immunohistochemistry of samples collected from mice and humans with SANFH and normal femoral heads revealed an imbalance between adipogenic and osteogenic differentiation in the necrotic area of femoral heads, with a significant decrease in the relative expression of HDAC10 in the necrotic area of femoral heads with SANFH. In summary, we speculate that HDAC10 affects the progression of SANFH by regulating BMSC adipogenic differentiation, a process possibly related to PPARγ histone acetylation. These findings provide a promising direction for the treatment of SANFH.

Three-dimensional mapping of necrotic lesions for early-stage osteonecrosis of the femoral head

BACKGROUND

There is a scarcity of evidence regarding the potential relationship between the size and location of necrotic lesions, which must be understood to provide optimal joint-preserving treatment. The purpose of this study was to characterize the distribution patterns of necrotic lesions of varying sizes in early-stage osteonecrosis of femoral head (ONFH) with the use of three-dimensional mapping.

METHODS

We retrospectively evaluated clinical CT images of the hips that were performed in the Third Hospital of Hebei Medical University from January 2018 to December 2022 and collected all CT images diagnosed with stage I and II ONFH. Three-dimensional structures that included both necrotic lesions and normal areas of the femoral heads were reconstructed and divided into eight regions to record their size and location. CT images for all lesions were superimposed onto a standard template, and three-dimensional mapping was created to determine the presence of concentrated areas of lesions.

RESULTS

In a cohort of 143 patients with stage I and II ONFH, a total of 150 hips were reviewed. For lesions with less than 15% of the femoral head volume, necrotic lesions predominantly involve regions I, III, and V, with region I showing concentration. For lesions with volumes ranging from 15 to 30%, necrotic lesions exhibited a wider distribution across regions I, II, III, IV, V, and VII, with significant concentrations in regions I, III, and V. For lesions exceeding 30% of the femoral head volume, the necrotic lesions were extensively distributed across nearly the entire femoral head, with a notable expansion of the concentrated necrotic areas.

CONCLUSIONS

The distribution of necrotic lesions varies with lesion size, with smaller lesions primarily concentrated in the anterior and medial regions of the femoral head, particularly in the anterosuperior region, while larger lesions expand to the lateral and inferior regions. These findings enhance existing classification systems and provide crucial insights for guiding hip-preserving surgical planning and approaches.

Loss of walking independence one year after primary total hip arthroplasty for osteonecrosis of the femoral head: incidence and risk prediction model

BACKGROUND

Assessment of postoperative ambulation in osteonecrosis of the femoral head (ONFH) patients treated with total hip arthroplasty (THA) is limited. This study aimed to define the incidence and risk factors for losing walking independence (LWI) at one-year postoperatively in patients with ONFH undergoing primary THA, and to establish and validate a predictive nomogram.

METHODS

This was a retrospective analysis of prospective collected data from patients admitted to a tertiary referral hospital with ONFH who underwent primary unilateral THA from October 2014 to March 2018. The Functional Independence Measure-Locomotion scale was used to quantify walking independence and was documented at a one-year continuous postoperative follow-up, which classified patients with a final score below 6 as LWI. Multivariate logistic regression identified independent risk factors for LWI, and a predictive nomogram was constructed based on the analysis results. The stability of the model was assessed using patients from April 2018 to April 2019 as an external validation set.

RESULTS

1152 patients were enrolled in the study, of which 810 were used in the training cohort and the other 342 for the validation cohort. The incidence of LWI was 5.93%. Multivariate analysis revealed that age 62 years or older (odd ratio (OR) = 2.37, 95% confidence interval (CI) 1.07-5.24), Charlson's comorbidity index 3 or higher (OR = 3.64, 95% CI 1.09-12.14), Association Research Circulation Osseous stage IV (OR = 2.16, 95% CI 1.03-4.54), reduced femoral offset (OR = 2.41, 95% CI 1.16-5.03), and a higher controlling nutritional status score (OR = 1.14, 95% CI 1.01-1.30) were independent risk factors of LWI. The nomogram had a concordance index of 0.773 and a Brier score of 0.049 in the training set, with corrected values of 0.747 and 0.051 after internal validation. The receiver-operating characteristic curve, calibration curve, Hosmer-Lemeshow test, and decision curve analysis all performed well in both the training and validation cohorts.

CONCLUSIONS

This study reported a 5.93% incidence of LWI and established a risk prediction model in patients undergoing THA for ONFH, supporting targeted screening and intervention to assist surgeons in assessing ambulation capacity and managing rehabilitation.

Risk assessment for femoral head collapse in osteonecrosis utilizing MRI-derived large lesion ratio: a retrospective cohort study

PURPOSE

This study aimed to developed a novel and practical method to quantify the involvement of lesion in osteonecrosis of the femoral head (ONFH). We hypothesized that the new metric large lesion ratio (LLR) had promising prognostic value.

METHODS

A total of 131 hips with non-traumatic ONFH were included in this retrospective study. Patient aged 18-60 with MRI-confirmed diagnosis, and a minimum of 2-year follow-up or radiographic collapse progression during follow-up were included. Patients with prior hip surgery, incomplete data or advanced ONFH at baseline (femoral head collapse > 2 mm or osteoarthritis) were excluded. Involvement of necrotic lesion was evaluated by calculating LLR. The differences of LLR between collapse progression and non-progression groups were investigated, and the differences among different scanning parameters groups were also examined. Prognostic value of LLR was examined by multivariate regression analysis. Receiver operating characteristic curves (ROC) were constructed and areas under the curve (AUC) were compared.

RESULTS

The median of LLR was 66.67% in the collapse progression group, which was significantly higher compared with 25.00% in the non-progression group (P < 0.001). Subgroups analysis showed that LLR were significantly higher in the collapse progression group of Japanese Investigation Committee type C1 (P < 0.001)and C2 (P = 0.002). Multivariate regression showed that LLR were independently correlated with collapse progression (OR, 1.46 [95% CI, 1.24-1.78]; P < 0.001). ROC analysis showed that the AUC for LLR was 0.84, outperforming the 0.74 AUC OF the JIC classification.

CONCLUSION

LLR could served as a efficient tool to assess the risk of collapse progression and guide the selection of treatment strategy.

Deep Circumflex Iliac Artery-vascularized Iliac Bone Graft for Femoral Head Osteonecrosis: Computed Tomography Anatomical Study

BACKGROUND

 Deep circumflex iliac artery (DCIA)-vascularized iliac graft transposition is a method for treating femoral head osteonecrosis but with inconsistent efficacy. We aim to improve the method of this surgery by recommending the optimal location of the iliac pedicle to satisfy the vascular length for transposition and the blood supply of the vascularized iliac graft.

METHODS

 The DCIA and its surrounding tissues were assessed on computed tomography angiography images for 100 sides (left and right) of 50 patients. The length of the vascular pedicle required for transposition and the length of the pedicle at different iliac spine positions were compared. The diameter and cross-sectional area of the DCIA and the distance between the DCIA and iliac spine were measured at different points to assess blood supply. We also compared differences in sex and left-right position.

RESULTS

 The diameter and cross-sectional area of the DCIA gradually decreased after crossing the anterior superior iliac spine (ASIS), and it approached the iliac bone. However, when the DCIA was 4 cm behind the ASIS (54 sides, 54%), it coursed posteriorly and superiorly away from the iliac spine. The vascular length of the pedicle was insufficient to transpose the vascularized iliac graft to the desired position when it was within 1 cm of the ASIS. The vascular length requirement was satisfied, and the blood supply was sufficient when the pedicle was positioned at 2 or 3 cm.

CONCLUSION

 To obtain a satisfactory pedicle length and sufficient blood supply, the DCIA pedicle of the vascularized iliac graft should be placed 2 to 3 cm behind the ASIS. The dissection of DCIA has slight differences in sex and left-right position due to anatomical differences.

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.

Effectiveness of various interventions for non-traumatic osteonecrosis: a pairwise and network meta-analysis

Background

Osteonecrosis of the femoral head (ONFH) is acknowledged as a prevalent, challenging orthopedic condition for patients.

Purpose

This study aimed to evaluate the efficacy of various interventions for non-traumatic ONFH and provide guidance for clinical decision-makers.

Methods

We searched PubMed, Embase, Cochrane Library, and Web of Science databases from inception to February 2023 for relevant randomized controlled trials evaluating treatments for femoral head necrosis, without language restrictions. Quality evaluation was performed using the Cochrane risk-of-bias assessment tool, and analysis was performed using Stata 15.1.

Results

Eleven randomized controlled trials were included in this study. The meta-analysis results revealed that CellTherapy [MD= -3.46, 95%CI= (-5.06, -1.85)], InjectableMed [MD= -3.68, 95%CI= (-6.11, -1.21)], ESWT [MD= -2.84, 95%CI= (-4.23, -1.45)], ESWT+InjectableMed [MD= -3.86, 95%CI= (-6.22, -1.53)] were significantly more effective in improving VAS pain score than CD+PTRI, as well as CD+BG+CellTherapy, and CD+BG. Furthermore, CD+BG+CellTherapy was better than CD+BG [MD= -0.97, 95%CI= (-1.71, -0.19)]. The SUCRA ranking for HHS score indicated that CellTherapy (77%) has the best effectiveness rate, followed by ESWT+InjectableMed (72.2%), ESWT (58.3%), InjectableMed (50%), CD+PTRI (31.4%), and CD+BG (11%). In terms of WOMAC and Lequesne scores, the meta-analysis showed no statistically significant differences between the experimental group CD+BG+CellTherapy and the control group CD+BG.

Conclusion

CellTherapy and non-surgical ESWT combined with medication or CellTherapy have the best effect on ONFH. Surgical CD+BG combined with CellTherapy is more effective than CD+BG alone. ESWT+InjectableMed is recommended for short-term or acute onset patients, while ESWT is recommended for long-term patients.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42024540122.