Osteonecrosis of the Femoral Head: Etiology, Investigations, and Management

Comparative Short-Term Outcomes of Femoral Neck System (FNS) and Cannulated Screw Fixation in Patients with Femoral Neck Fractures: A Multicenter Study

Background

Femoral neck fractures need to be treated in their early stages with accurate reduction and stable fixation to reduce complications. The authors compared the early radiologic outcomes of femoral neck fractures treated with the recently introduced Femoral Neck System (FNS, Depuy-Synthes) with conventional cannulated screws (CS) in a multicenter design. Furthermore, the factors associated with early failure after FNS were analyzed.

Methods

The FNS group included 40 patients treated between June 2019 and January 2020, and the CS group included 65 patients treated between January 2015 and May 2019. The operation was performed in 3 university hospitals. Patient demographics, fracture classification, postoperative reduction quality, sliding distance of FNS or CS, union and time to union, and complication rates were examined. Logistic regression analysis was performed on candidate factors for early failure of the FNS group.

Results

The FNS group had a 90% union rate and a mean time to union of 4.4 months, while the CS group had similar results with an 83.1% union rate and a mean time to union of 5.1 months. In the subgroup analysis of Pauwels type III fractures, the union rates were 75.0% and 58.8% in the FNS and CS groups, respectively, and the time to union was significantly shorter in the FNS group with 4.8 months compared to 6.8 months in the CS group. Early failure rate within 6 months of FNS fixation was observed to be 10%, which included 3 reduction failures and 1 excessive sliding with a broken implant. Risk factors for early failure after FNS were identified as displaced fractures (Garden classification type III or IV), poor reduction quality, longer tip-apex distance, greater sliding distance, and 1-hole implants, of which sliding distance was the only significant risk factor in multivariate analysis.

Conclusions

In femoral neck fractures, FNS and CS did not show significant differences for short-term radiologic results. FNS resulted in shorter operative time than cannulated screw fixation and favorable outcomes in Pauwels type III femoral neck fractures. The FNS could be considered a reliable and safe alternative to CS when treating femoral neck fractures.

Long-Term Outcomes of Cementless Bipolar Hemiarthroplasty in Young Patients With Osteonecrosis of the Femoral Head: The Impact of Implant Improvements and Preoperative Stage

Introduction Advancements in bipolar hemiarthroplasty (BHA) implants in the mid-1990s contributed to favorable short-term outcomes for osteonecrosis of the femoral head (ONFH), particularly in cases without acetabular cartilage lesions. Nevertheless, long-term results remain unclear. In this study, we investigated (i) the impact of new-generation BHA implants and (ii) the effect of the preoperative stage on long-term outcomes in young patients with ONFH. Methods The records of consecutive patients with ONFH who underwent cementless BHA were retrospectively reviewed. Patients aged ≥60 years, with <10 years of follow-up, or who underwent acetabular reaming during surgery were excluded. Radiographical and clinical outcomes of patients who received first-generation BHAs and new-generation BHAs (developed after 1998) were compared by stratifying based on preoperative stage 2/3A and 3B/4, according to the Japanese Investigation Committee classification. Results Overall, 50 hips from 39 patients (mean age: 44.6 years; 64% male) with an average follow-up of 18.6 years were included. The frequency of advanced-stage patients was significantly higher in the first-generation BHA group than in the new-generation group. Regarding postoperative outcomes, the first-generation BHA group had higher acetabular erosion grades (p<0.001) and more femoral component loosening than those in the new-generation group (p<0.001). Revisions were performed in eight hips (seven in the first-generation and one in the new-generation BHA groups, p<0.001). In the new-generation BHA group, there were no significant differences in patient background between stage 2/3A and 3B/4 groups, and only one case in the stage 3B/4 group required revision. In the new-generation group, the grade of acetabular erosion was significantly higher for stage 3B/4 than stage 2/3A (p<0.001); other radiographical and clinical outcomes did not differ significantly between stages. Conclusion New-generation BHAs have significantly better implant survival rates for early-stage ONFH than those of first-generation BHAs. These findings indicate that BHA is an acceptable treatment option for early-stage ONFH in young patients.

Treatment of osteonecrosis of the femoral head with multiple drilling and bone marrow mesenchymal stem cells expanded ex vivo plus biomolecules derived from platelet-rich plasma: a case report

Osteonecrosis of the femoral head (ONFH) is a debilitating condition that predominantly affects young individuals, resulting in disability and involving significant healthcare costs. Therefore, it is crucial to develop an effective therapeutic strategy to treat this debilitating disease. In this context, autologous bone marrow-derived mesenchymal stem cells (auto-BM-MSCs) have emerged as a promising approach for treating ONFH. In this case report, we applied this therapy to a patient with ONFH and evaluated both its safety and therapeutic benefits. The treatment consisted of the administration of a single dose of 4×107 ex vivo-expanded auto-BM-MSCs combined with biomolecules derived from platelet-rich plasma. These therapeutic agents were injected into the necrotic zone after accessing it through the technique of multiple small drillings. Subsequently, the progression of ONFH was assessed after 18 months of the auto-BM-MSC administration. Radiographic evaluation showed that the initial femoral head flattening persisted, but no further progression or coxofemoral arthritic changes were observed. Nevertheless, magnetic resonance imaging (MRI) demonstrated a significant improvement in the affected femoral head's area, resulting in a Kerboull angle of 80°, without evidence of flattening or a notable collapse compared to the preoperative condition. Furthermore, the patient exhibited a remarkable functional improvement, as evidenced by a modified Harris hip score of 90 points. The absence of any additional surgery reinforces the positive outcomes achieved through this therapeutic intervention. In conclusion, our case study provides evidence for using the ex vivo-expanded auto-BM-MSCs in combination with platelet-rich plasma-derived biomolecules as a viable and safe treatment for ONFH. However, further research and clinical trials are necessary to validate these promising findings.

GC-MS based comparative metabolomic analysis of human cancellous bone reveals the critical role of linoleic acid metabolism in femur head necrosis

INTRODUCTION

Femur head necrosis (FHN) is a challenging clinical disease with unclear underlying mechanism, which pathologically is associated with disordered metabolism. However, the disordered metabolism in cancellous bone of FHN was never analyzed by gas chromatography-mass spectrometry (GC-MS).

OBJECTIVES

To elucidate altered metabolism pathways in FHN and identify putative biomarkers for the detection of FHN.

METHODS

We recruited 26 patients with femur head necrosis and 22 patients with femur neck fracture in this study. Cancellous bone tissues from the femoral heads were collected after the surgery and were analyzed by GC-MS based untargeted metabolomics approach. The resulting data were analyzed via uni- and multivariate statistical approaches. The changed metabolites were used for the pathway analysis and potential biomarker identification.

RESULTS

Thirty-seven metabolites distinctly changed in FHN group were identified. Among them, 32 metabolites were upregulated and 5 were downregulated in FHN. The pathway analysis showed that linoleic acid metabolism were the most relevant to FHN pathology. On the basis of metabolites network, L-lysine, L-glutamine and L-serine were deemed as the junctions of the whole metabolites. Finally, 9,12-octadecadienoic acid, inosine, L-proline and octadecanoic acid were considered as the potential biomarkers of FHN.

CONCLUSION

This study provides a new insight into the pathogenesis of FHN and confirms linoleic acid metabolism as the core.

Core decompression combined with local DFO administration loaded on polylactic glycolic acid scaffolds for the treatment of osteonecrosis of the femoral head: a pilot study

BACKGROUND

Deferoxamine (DFO) angiogenesis induction potential has been demonstrated in earlier studies, but not in the osteonecrosis of the femoral head (ONFH). In this study, we evaluated the outcome of ONFH treated with combined core decompression and local DFO administration loaded on Polylactic Glycolic Acid (PLGA).

PATIENTS AND METHODS

In a pilot experimental study, six patients (10 hips) with early-stage non-traumatic ONFH were treated by core decompression, and concurrent injection of local DFO loaded on PLGA scaffold into the subchondral femoral head. Outcome measures were evaluated before the surgery and 12 and 24 months after the surgery and included visual analog scale (VAS) for pain, modified Merle d'Aubigné-Postel (MAP) score for hip function by MRI, and rate of osteonecrosis assessed by the modified.

RESULTS

The mean MPA score was 14.7 ± 1.16 before the surgery and 16.7 ± 1.41 one year after the surgery (P = 0.004). The mean VAS for pain was 4.7 ± 1.25 before the surgery and 1.8 ± 1.03 one year after the surgery (P = 0.005). The mean Kerboul angle was 219 ± 58.64 before the operation and 164.6 ± 41.82 one year after the operation (P < 0.001). Osteonecrosis progression or collapse was not seen in any of the patients at the final follow-up. No postoperative side effect attributed to the DFO was noticed, as well.

CONCLUSION

In short-term follow-up, combined core decompression and local DFO administration not only prevent the progression of ONFH but also reduces the rate of osteonecrosis significantly. However, future controlled studies are required to confirm the present results.

TRIAL REGISTRATION

IRCT20161121031003N3, 16/04/2019.

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

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Not applicable.

TRIAL REGISTRATION

Not applicable.

The Antagonism of Neuropeptide Y Type I Receptor (Y1R) Reserves the Viability of Bone Marrow Stromal Cells in the Milieu of Osteonecrosis of Femoral Head (ONFH)

Neuropeptide Y (NPY)-Y1 receptor (Y1R) signaling is known to negatively affect bone anabolism. Our study aimed at investigating the impact of NPY-Y1R signaling in the pathogenesis of glucocorticoid-related osteonecrosis of the femoral head (ONFH). Femoral heads were retrieved from 20 patients with and without ONFH, respectively. The bone marrow stromal cells (BMSCs) from ONFH femoral heads were treated with Y1R agonists and antagonists for subsequent analysis. We showed that the local NPY expression level was lower in ONFH heads. The Y1R agonists and antagonists disturb and facilitate the survival of BMSCs. The transcription of stromal derived factor-1 (SDF-1) was enhanced by Y1R antagonists. Our study showed that the local NPY expression level was lower in ONFH heads. Y1R antagonists facilitate the survival of BMSCs and stimulate the transcription of SDF-1 by BMSCs. These findings shed light on the role of NPY-Y1R signaling in the pathogenesis of ONFH.

Mesenchymal stem cell-derived extracellular vesicles: a possible therapeutic strategy for orthopaedic diseases: a narrative review

Accumulating evidence suggests that the therapeutic role of mesenchymal stem cells (MSCs) in bone diseases is closely related to paracrine-generated extracellular vesicles (EVs). MSC-derived EVs (MSC-EVs) carry proteins, nucleic acids, and lipids to the extracellular space and affect the bone microenvironment. They have similar biological functions to MSCs, such as the ability to repair organ and tissue damage. In addition, MSC-EVs also have the advantages of long half-life, low immunogenicity, attractive stability, ability to pass through the blood-brain barrier, and demonstrate excellent performance with potential practical applications in bone diseases. In this review, we summarise the current applications and mechanisms of MSC-EVs in osteoporosis, osteoarthritis, bone tumours, osteonecrosis of the femoral head, and fractures, as well as the development of MSC-EVs combined with materials science in the field of orthopaedics. Additionally, we explore the critical challenges involved in the clinical application of MSC-EVs in orthopaedic diseases.

Multiple Drilling with Recombinant Human Bone Morphogenetic Protein-2 in Korean Patients with Non-Traumatic Osteonecrosis of the Femoral Head: A Prospective Randomized Pilot Study with a Minimum Two-Year Follow-Up

We sought to determine whether multiple drilling (MD) combined with the injection of recombinant human bone morphogenetic protein-2 (rhBMP-2) and β-tricalcium phosphate (β-TCP) could improve survival of the femoral head in pre-collapse lesions of non-traumatic osteonecrosis of the femoral head (ONFH) as compared with MD alone. We conducted a single-site, off-label, comparative and prospective cohort study between November 2017 and May 2019. We enrolled 25 hips (25 patients) with non-traumatic ONFH (Ficat–Arlet stage 2A or less). We performed a survival analysis, and the primary outcome was the occurrence of femoral head collapse on follow-up radiograph. Our cohort consisted of 11 men and 9 women of age 52.5 ± 8.8 years and a body mass index of 24.3 ± 3.0 kg/m². The femoral heads were preserved in 9 hips (45.0%) and collapsed in 11 hips (55.0%) at the final follow-up; mean survival to collapse was 6.9 (range 2.8–13.5) months. There were no significant differences in the survival of the femoral head between the MD alone group and the MD with rhBMP-2 and β-TCP group (five hips survived, 50% vs. four hips survived, 40%, respectively; p = 0.83). MD combined with the injection of rhBMP-2 and β-TCP did not improve femoral head survival compared to MD alone in the pre-collapse non-traumatic ONFH lesion.

Case report: Directional infusion of peripheral blood stem cells into the necrotic zone in femoral heads through the medial circumflex femoral artery: A tracing study

Objective

This study aimed to explore whether peripheral blood stem cells (PBSCs) infused through the medial circumflex femoral artery to treat osteonecrosis of the femoral head (ONFH) could migrate into the necrotic area of femoral head.

Methods

We collected PBSCs from a patient who had bilateral ONFH by apheresis technique using COBE spectra apheresis system (COBE BCT Inc, Lakewood, CO, USA) after subcutaneous injections of granulocyte-colony stimulating factor (G-CSF) at a dosage of 10 μg/kg for 4 days to mobilize PBSCs. After that, 100 MBq 2-[¹⁸F]-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) was used to label PBSCs. ¹⁸F-FDG labeled PBSCs were infused into the left femoral head via the medial circumflex femoral artery to treat ONFH. Then the patient was underwent three-dimensional positron emission tomography (3D-PET) examination 60 min after cell infusion to monitor the biological distribution of ¹⁸F-FDG-labeled PBSCs, and to observe whether the transplanted PBSCs could migrate into the necrotic area of femoral head.

Results

The total number of monouclear cells in the peripheral blood stem cell suspension was 1.95 × 10⁸ which contained 2.20 × 10⁶ CD34⁺ cells. The activity of ¹⁸F-FDG in the labeled cells was 1.8Bq/10³ monouclear cells. 3D-PET imaging showed that ¹⁸F-FDG radioactivity was detected in the necrotic area of femoral head, acetabulum and femoral bone marrow cavity after transplantation of ¹⁸F-FDG-labeled PBSCs via the medial circumflex femoral artery. It is worth noting that although PBSCs labeled with ¹⁸F-FDG were widely distributed around the hip, such as femoral bone marrow cavity, femoral head and acetabulum, PBSCs were generally located in the necrotic area of femoral head.

Conclusions

PBSCs could enter into the femoral head and migrate into the necrotic field of femoral head participating in the repair of osteonecrosis after infusion through the medial circumflex femoral artery.

Cementless femoral neck endoprosthesis SPIRON in men in aspects of clinical status and quality of life in an average 7-year follow-up

Background

We report the clinical evaluation, quality of life and pain assessment in patients who had a femoral neck SPIRON endoprosthesis.

Methods

The study group consisted of 27 men in whom 35 femoral neck endoprosthesis were implanted (8 on the left side, 12 on the right side and 7 bilateral) due to idiopathic osteoarthritis of the hip (20 patients) or avascular femoral osteonecrosis (7 patients) in a mean 7-year follow-up.

Results

The median pre-operative Harris Hip score (HHS) was 35.5 and post-operative 98.5 (p < 0.001). The median WOMAC HIP score was pre-operatively 57 and post-operatively 0 (p < 0.001). The median SF-12 score was pre-operatively 4 and post-operatively 33 (p < 0.001). The median pain assessment in VAS scale was 7 pre-operatively and 0 post-operatively (p < 0.001).

Conclusions

The results of all examined patients have changed significantly in every category showing that SPIRON endoprosthesis improved their quality of life and statistically reduced pain ailments. Moreover we have proved that higher BMI (> 30) is associated with worse operation outcomes.

Updates on Management of Avascular Necrosis Using Hip Arthroscopy for Core Decompression

Osteonecrosis of the femoral head (ONFH) is caused when circulation within the femoral head is disrupted. Etiology of this disease is characterized by either traumatic events or atraumatic risk factors, such as chronic alcohol consumption or glucocorticoid use. ONFH commonly presents as pain in the groin, gluteus muscles, and/or knee with reductions in internal rotation range of motion of the hip. ONFH pathology can be confirmed with radiographic or advanced imaging and characterized by stage, size and location of the lesion. Treatment for ONFH consists of conservative and therapeutic methods as well as surgical intervention. Historically, ONFH has been treated using total hip arthroplasty (THA), but with increasing incidence in a younger, active population, measures to preserve the native hip joint have been explored. Recent advancements in hip arthroscopy and arthroscopy-assisted core decompression have led to improved outcomes, reduced pain and higher hip survival rate for early onset ONFH compared with more invasive approaches such as THA. Biologic treatments combined with arthroscopic core decompression have also shown improved outcomes and quality of life in few reports, suggesting a potential role for biologic adjuncts. The current study provides a comprehensive review and update on the literature surrounding arthroscopy-assisted core decompression for patients with ONFH.

Integrative analyses of genes related to femoral head osteonecrosis: an umbrella review of systematic reviews and meta-analyses of observational studies

Background

Femoral head osteonecrosis (FHON) is a worldwide challenging clinical topic. Steroid use is one of the main etiologies of FHON. There are several genetic variants associated with FHON. Therefore, the purpose of this umbrella review was to provide a comprehensive summary of a meta-analysis and systematic review of genetic variations associated with nonsteroidal and steroid-induced FHON.

Methods

The eligible studies were selected from the PubMed and MEDLINE databases for the collection of diverse systematic meta-analyses and reviews. The genetic main effect score was assigned using the Human Genome Epidemiology Network’s Venice criteria to assess the cumulative evidence on the effects of a single nucleotide polymorphism (SNP) on FHON.

Results

Eight articles reported the meta-analysis of candidate SNP-based studies covering eight genes and 13 genetic variants. In the nonsteroid-induced FHON genetic variants including rs2012390 and rs11225394 in MMP8, rs1800629 and rs361525 in tumor necrosis factor (TNF)-α, VNTR in intron 4, rs1799983 and rs2070744 in endothelial nitric oxide synthase (eNOS), rs2010963 in vascular endothelial growth factor (VEGF), and rs6025 in factor V showed significance in each reference. The steroid-induced FHON genetic variants including rs693 and rs1042031 in apolipoprotein (Apo)B, rs1045642 in ABCB1, and rs1799889 in PAI-1 showed significance in each reference.

Conclusion

Based on the systematic review conducted in this study, we organized the genomes associated with FHON and looked at each contribution. Our results could give an integrative approach for understanding the mechanism of FHON etiology. It is expected that these results could contribute to the strategy of prediagnosis, evaluating the individual risk of nonsteroid-induced and steroid-induced FHON.

Level of Evidence: Level I.

Preliminary report of the outcomes and indications of single approach, double-channel core decompression with structural bone support and bone grafting for osteonecrosis of the femoral head

Background

To report the outcomes of the single approach to double-channel core decompression and bone grafting with structural bone support (SDBS) for osteonecrosis of the femoral head (ONFH) and define the indications.

Methods

One-hundred-and-thirty-nine hips in 96 patients (79 males, 17 females; mean age 37.53±10.31 years, range 14–58 years; mean body mass index 25.15±3.63 kg/m²) were retrospectively analysed. The Harris hip score (HHS) was used to assess hip function, and radiographs were used to assess the depth of femoral head collapse. Treatment failure was defined as the performance of total hip arthroplasty (THA). The variables assessed as potential risk factors for surgical failure were: aetiology, Japanese Osteonecrosis Investigation Committee (JIC) type, age, and Association Research Circulation Osseous (ARCO) stage. Complications were recorded.

Results

The mean follow-up time was 29.26±10.02 months. The HHS increased from 79.00±13.61 preoperatively to 82.01±17.29 at final follow-up (P=0.041). The average HHS improvement was 3.00±21.86. The combined excellent and good rate at final follow-up (65.6%) was significantly higher than that before surgery (34.5%) (P<0.05). On radiographic evaluation, 103 (74.1%) hips remained stable, while 36 (25.9%) had femoral head collapse or aggravation of ONFH. THA was performed in 18 hips. Thus, the overall femoral head survival rate was 87.05% (121/139). The success rate was adversely affected by JIC type, but not by aetiology, age, or ARCO stage. The only complication was a subtrochanteric fracture in one patient.

Conclusion

The SDBS may be an effective method to delay or even terminate the natural progression of ONFH, especially for patients with JIC types B and C1. The SDBS represents a new option for treating early-stage ONFH.

Tissue Engineering Strategies for Treating Avascular Necrosis of the Femoral Head

Avascular necrosis (AVN) of the femoral head commonly leads to symptomatic osteoarthritis of the hip. In older patients, hip replacement is a viable option that restores the hip biomechanics and improves pain but in pediatric, adolescent, and young adult patients hip replacements impose significant activity limitations and the need for multiple revision surgeries with increasing risk of complication. Early detection of AVN requires a high level of suspicion as diagnostic techniques such as X-rays are not sensitive in the early stages of the disease. There are multiple etiologies that can lead to this disease. In the pediatric and adolescent population, trauma is a commonly recognized cause of AVN. The understanding of the pathophysiology of the disease is limited, adding to the challenge of devising a clinically effective treatment strategy. Surgical techniques to prevent progression of the disease and avoid total hip replacement include core decompression, vascular grafts, and use of bone-marrow derived stem cells with or without adjuncts, such as bisphosphonates and bone morphogenetic protein (BMP), all of which are partially effective only in the very early stages of the disease. Further, these strategies often only improve pain and range of motion in the short-term in some patients and do not predictably prevent progression of the disease. Tissue engineering strategies with the combined use of biomaterials, stem cells and growth factors offer a potential strategy to avoid metallic implants and surgery. Structural, bioactive biomaterial platforms could help in stabilizing the femoral head while inducing osteogenic differentiation to regenerate bone and provide angiogenic cues to concomitantly recover vasculature in the femoral head. Moreover, injectable systems that can be delivered using a minimal invasive procedure and provide mechanical support the collapsing femoral head could potentially alleviate the need for surgical interventions in the future. The present review describes the limitations of existing surgical methods and the recent advances in tissue engineering that are leading in the direction of a clinically effective, translational solution for AVN in future.

Multi-joint steroid-induced avascular necrosis in a malignant brain tumor patient

Avascular necrosis (AVN) is a rare but serious adverse event associated with the use of corticosteroids for long durations or at high doses. This case report describes a 47-year-old female patient with low-grade astrocytoma who was initiated on low-dose dexamethasone for symptom management. The patient developed joint pain 1 year after steroid exposure, then was found to have AVN of the hip followed by multiple other joints. This case report highlights the extent to which AVN can occur in patients with brain tumors following a short course of low-dose corticosteroids. Careful evaluation of and monitoring for the development of AVN should occur frequently in patients with brain tumors given the frequent use of corticosteroids for symptom management in this population.

Core decompression and bone marrow aspirate concentrate injection for Avascular Necrosis (AVN) of the femoral head: A scoping review

BACKGROUND

Various joint preserving treatments are available for use in Avascular Necrosis of the femoral head. Most of these are effective in the pre-collapse stage of the disease. This review aimed to evaluate the effectiveness of core decompression and Bone Marrow Aspirate Concentrate in various stages of AVN, in modifying the progression of the disease and the need for hip replacement.

MATERIAL AND METHODS

The Preferred Reporting Items for Systematic reviews and Meta-Analysis Extension for Scoping Reviews reporting guidelines were followed. The literature search was conducted from inception till 2^nd May 2021, on the PUBMED, SCOPUS, and Google Scholar search engines, using "bone marrow aspirate concentrate osteonecrosis femur" and "bmac osteonecrosis femur" as the keywords. In all these studies, Core Decompression with Bone marrow Aspirate concentrate was performed. The evaluation was done based on the progression of osteonecrosis, improvement in functional outcomes and the conversion to total hip arthroplasty.

RESULTS

We have analyzed 612 hips from11 studies, based on our inclusion and exclusion criteria. The mean age of the patients was 38.27 years. There was a predominance of males. The grade of AVN ranged from grade 1 to 4. The average follow-up period of the cases ranged from 2 to 12 years (average: 4.38 years). The functional scores were improved in the majority of cases. Radiographic progression occurred in 23.5% of hips, and the Total Hip Arthroplasty was performed in 14.9% of hips.

CONCLUSIONS

Core decompression with Bone Marrow Aspirate Concentrate in pre-collapse stages of the disease is beneficial in improving the functions scores and for reducing the radiological progression of the disease and need for total hip arthroplasty, in the majority of cases.

Neohesperidin promotes the osteogenic differentiation of human bone marrow stromal cells by inhibiting the histone modifications of lncRNA SNHG1

Neohesperidin (NH) was reported to regulate osteoclastic differentiation, while LncRNA SNHG1 could inhibit osteogenic differentiation of bone marrow stromal cells (BMSCs). In this study, we aimed to explore whether SNHG1-mediated osteogenic differentiation could be regulated by NH. Osteonecrosis and adjacent tissues, as well as normal bone marrow samples were gathered. BMSCs were isolated from normal bone marrow samples by Ficoll density gradient and identified by flow cytometry. Histopathological changes of tissues were detected by hematoxylin-eosin staining. After the treatment with NH or transfection, cell viability, osteogenic differentiation, and the activity of alkaline phosphatase (ALP) in BMSCs were detected by MTT, alizarin red staining, and microplate method, respectively. The histone modification and expressions of SNHG1 and osteogenic marker genes in tissues or BMSCs were detected by q-PCR and Chromatin Immunoprecipitation (ChIp). SNHG1 was highly expressed in osteonecrosis tissues, and typical signs of empty lacunae appeared in the necrotic tissues zone. NH increased viability and osteogenic differentiation of BMSCs, activity of ALP, and expressions of RUNX2, OCN and ALP. NH decreased both SNHG1 expression and H3K4me3 (activating histone modification) occupancies and increased H3K27me3 (inhibiting histone modification) occupancies of SNHG1. Furthermore, siSNHG1 enhanced osteogenic differentiation of BMSCs and expressions of RUNX2, OCN and ALP, while SNHG1 overexpression did the opposite and reversed the effects of NH on the osteogenic differentiation of BMSCs. In a word, NH promotes the osteogenic differentiation of human BMSCs by inhibiting the histone modifications of lncRNA SNHG1.

Osteonecrosis of the Femoral Head in Patients with Hypercoagulability-From Pathophysiology to Therapeutic Implications

Osteonecrosis of the femoral head (ONFH) is a debilitating disease with major social and economic impacts. It frequently affects relatively young adults and has a predilection for rapid progression to femoral head collapse and end-stage hip arthritis. If not diagnosed and treated properly in the early stages, ONFH has devastating consequences and leads to mandatory total hip arthroplasty. The pathophysiology of non-traumatic ONFH is very complex and not fully understood. While multiple risk factors have been associated with secondary ONFH, there are still many cases in which a clear etiology cannot be established. Recognition of the prothrombotic state as part of the etiopathogeny of primary ONFH provides an opportunity for early medical intervention, with implications for both prophylaxis and therapy aimed at slowing or stopping the progression of the disease. Hereditary thrombophilia and hypofibrinolysis are associated with thrombotic occlusion of bone vessels. Anticoagulant treatment can change the natural course of the disease and improve patients' quality of life. The present work focused on highlighting the association between hereditary thrombophilia/hypofibrinolysis states and ONFH, emphasizing the importance of identifying this condition. We have also provided strong arguments to support the efficiency and safety of anticoagulant treatment in the early stages of the disease, encouraging etiological diagnosis and prompt therapeutic intervention. In the era of direct oral anticoagulants, new therapeutic options have become available, enabling better long-term compliance.

Osteonecrosis of the hip: is there a difference in the survivorship of total hip arthroplasty with or without previous vascular iliac bone grafting?

Background

Osteonecrosis of the femoral head (ONFH) is a debilitating condition. Vascularized iliac bone graft (VIBG) is a joint-preserving surgery to improve blood supply to the avascular portion of the femoral head which may delay secondary osteoarthritis and total hip arthroplasty (THA). However, whether VIBG will affect the subsequent THA survivorship and outcomes are still uncertain.

Methods

Implant survivorship and clinical outcomes were compared between 27 patients who had undergone prior VIBG and 242 patients who had only undergone THA for ONFH. Baseline characteristics and the postoperative Harris Hip Score (HHS) were also recorded and compared between the two groups. Implant survivorship was determined using Kaplan-Meier survival analysis.

Results

The overall implant survival for all patients who had a primary diagnosis of ONFH and eventually underwent THA was 92.9%. There was no significant difference in the implant survivorship between the group who directly received THA (survivorship of 93%) and the group which failed VIBG and was subsequently converted to THA (survivorship of 91.9%) (p = 0.71). In addition, higher THA revision rates were associated with smokers and drinkers.

Conclusions

VIBG may be a reasonable option as a “buy-time” procedure for ONFH. Even if conversion to THA is eventually required, patients may be reassured that the overall survivorship and clinical outcomes may not be compromised. Patients are recommended to give up smoking and binge drinking prior to THA to increase implant survival rate.

IKKe in osteoclast inhibits the progression of methylprednisolone-induced osteonecrosis

Previous studies have described that NF-κB signaling mediated by NFκB-inducing kinase (NIK) plays a critical role of the differentiation of osteoclasts. We aim to explore the role of IKKe in methylprednisolone -induced osteonecrosis of the femoral head (ONFH). Methylprednisolone-induced ONFH mice model was successfully established, and subjected to micro computed tomography to detect the femoral head image of the mice. Bone marrow cells from experimental mice were collected and cultured. qPCR and immunoblot were performed to examine the possible signal pathways of IKKe involvement, and osteoclast-related gene expressions in IKKe+/+ and IKKe-/- cells in vitro and in vivo were examined. It was found that the levels of IKKe decreased in ONFH patients, and IKKe interacted with NIK in the NF-κB signal pathway to suppress osteoclasts via inhibiting the transcription of NIK. Furthermore, IKKe knockout promoted the osteoclastogenesis in mice model. Finally, IKKe knockout suppressed methylprednisolone-induced ONFH and pro-inflammatory responses in mice model. Our findings show a mechanism of IKKe inhibition of the progression of methylprednisolone-induced ONFH via the NIK/NF-κB pathway.

Autologous bone marrow derived mesenchymal stem cell therapy for osteonecrosis of femoral head: A systematic overview of overlapping meta-analyses

STUDY DESIGN

Systematic Review.

OBJECTIVES

We performed this systematic overview on the overlapping meta-analyses that analyzed autologous bone marrow-derived mesenchymal stem cell(BM-MSC) therapy along with core decompression(CD) for the management of osteonecrosis of the femoral head(ONFH) and identify which study provides the current best evidence on the topic and generate recommendations for the same.

MATERIALS AND METHODS

We conducted independent and duplicate electronic database searches in PubMed, Web of Science, Embase, Cochrane Database of Systematic Reviews, and the Database of Abstracts of Reviews of Effects till September 2020 for meta-analyses that analyzed the efficacy of BM-MSC therapy along with CD for ONFH. Methodological quality assessment was made using Oxford Levels of Evidence, AMSTAR scoring, and AMSTAR 2 grades. We then utilized the Jadad decision algorithm to identify the study with the highest quality to represent the current best evidence to generate the recommendation.

RESULTS

6 meta-analyses fulfilling the eligibility criteria were included. The AMSTAR scores of the included studies varied from 4 to 9 (mean:7) and all the included studies had critically low reliability in their summary of results due to their methodological flaws according to AMSTAR 2 grades. The current best evidence showed that utilization of BM-MSC therapy along with CD for ONFH resulted in significant improvement in Harris hip scores at 12 and 24 months along with a significant reduction in the necrotic area of the femoral head and the rate of conversion to total hip arthroplasty(THA) without a significant rise in adverse events due to the procedure.

CONCLUSION

Based on this systematic overview, we give a Level II recommendation that BM-MSC therapy is more efficacious along with CD in the management of ONFH compared to CD alone. BM-MSC therapy provides better pain relief with significant functional improvement and delaying the collapse of the femoral head thereby preventing further treatment such as THA.

Novel MRI technique for the quantification of biochemical deterioration in steroid-induced osteonecrosis of femoral head: a prospective diagnostic trial

To explore the novel magnetic resonance imaging techniques, IVIM-DWI and IDEAL-IQ in detecting bone marrow fat and microcirculation in steroid-induced osteonecrosis of the femoral head (SIONFH). In this prospective study, 49 patients (80 hips) with SIONFH taking glucocorticoids and 24 healthy volunteers (48 hips) were recruited and assessed by T1WI, T2WI/fs, IDEAL-IQ and IVIM-DWI. The affected hips, contralateral asymptomatic hips and normal hips, as well as normal, penumbra and necrotic areas in the affected hips, were classified and evaluated. Imaging results were compared with histologic bone sections obtained from SIONFH patients undergoing surgery. The fat fraction (FF) and perfusion fraction (f) differences between groups were analyzed using analysis of variance, the LSD t-test, Pearson correlation analysis and ROC curve analysis. Our results demonstrate that IDEAL-IQ (FF) and IVIM-DWI (f) enable the classification of SIONFH at different ARCO stages. The FF was positively associated with the progression of the disease (r = 0.72), in contrast to f (r = -0.17). The FF and f were significantly different among the necrotic, penumbra and normal areas, and they were negatively correlated with each other (r = -0.37). The diagnostic sensitivity and specificity of IDEAL-IQ were 96.9% and 86.7%, and those of IVIM-DWI were 72.34% and 58.33%, respectively. The FF in contralateral asymptomatic hips was significantly higher than in normal hips, but no difference was found for f. IDEAL-IQ, and not IVIM-DWI, was identified to successfully detect bone marrow fat, which is beneficial to the diagnosis of the severity of SIONFH.

Neohesperidin Ameliorates Steroid-Induced Osteonecrosis of the Femoral Head by Inhibiting the Histone Modification of lncRNA HOTAIR

Background

Neohesperidin (NH) and lncRNA HOTAIR (HOTAIR) could regulate osteoclastic and osteogenic differentiation. This study aimed to explore whether HOTAIR-mediated osteogenic differentiation was regulated by NH.

Methods

Steroid-induced osteonecrosis of the femoral head (SONFH) mice model was established. Histopathological changes in mouse osteonecrosis tissues were detected by hematoxylin-eosin staining. Bone marrow stromal cells (BMSCs) were isolated from healthy mice bone marrow samples by Ficoll density gradient and identified by flow cytometry. After treating the BMSCs with NH and dexamethasone or transfecting with HOTAIR overexpression plasmids and siHOTAIR, histone modification of HOTAIR, the cell viability, osteogenic differentiation, and adipogenic differentiation were detected by chromatin immunoprecipitation, MTT, Alizarin Red and Oil Red O staining, respectively. The expressions of HOTAIR and differentiation-related factors in the BMSCs were detected by RT-qPCR and Western blot.

Results

HOTAIR was highly expressed in SONFH model mice. NH ameliorated histopathological changes in the model mice, but the effect was reversed by overexpressed HOTAIR. NH increased viability of BMSCs and the H3K27me3 occupancy of HOTAIR, but decreased the expression and the H3K4me3 occupancy of HOTAIR. HOTAIR expression was down-regulated in BMSCs after osteogenic differentiation but was up-regulated after adipogenic differentiation. HOTAIR overexpression inhibited osteogenic differentiation and the expressions of RUNX2, OCN, and ALP, but increased adipogenic differentiation and the expressions of LPL and PPARr in BMSCs; moreover, the opposite results were observed in siHOTAIR.

Conclusion

NH ameliorated SONFH by inhibiting the histone modifications of HOTAIR.

Prediction of the progression of femoral head collapse in ARCO stage 2-3A osteonecrosis based on the initial bone resorption lesion

OBJECTIVES

To predict the progression of femoral head collapse in Association Research Circulation Osseous (ARCO) Stage 2-3A osteonecrosis based on the initial bone resorption lesion.

METHODS

A retrospective analysis of the location, attenuation, and maximum area in coronal position (MAC) of the initial bone resorption lesion in ARCO Stage 2 and 3A was conducted in 85 cases of osteonecrosis of the femoral head (ONFH). The cases were divided into rapid and slow progression groups according to whether femoral head collapse at follow-up was greater than 2 mm. The characteristics of the bone resorption lesion between the two groups were compared by analysis of variance. Receiver operating characteristic curve was used to analyze the MAC, regions of A2, and C1 of bone resorption lesion in predicting collapse progression.

RESULTS

The MAC of initial bone resorption lesion in rapid progression group (117.8 ± 72.1 mm²) was significantly larger than slow (53.1 ± 39.5 mm²) (p < 0.001). Regions of A2 and C1 involved were significantly higher in rapid than slow progression group. The area under the receiver operating characteristic curve of MAC, regions of A2 and C1 of bone resorption lesion to predict collapse progression were 0.81, 0.72 and 0.62 respectively. A threshold MAC of 49 mm² had sensitivity of 86.1% and specificity of 61.9% to predict collapse progression.

CONCLUSIONS

The MAC of initial bone resorption lesion in ARCO Stage 2-3A ONFH can predict the progression of femoral head collapse. If it is greater than 49 mm² and located in regions of A2 and C1, the possibility of rapid progression is high, active monitoring and intervention should be recommended.

ADVANCES IN KNOWLEDGE

This study is the first to find that the maximum area in coronal position of initial bone resorption lesion in ARCO Stage 2 or 3A can predict progression of the femoral head collapse with a threshold of 49 mm². If the maximum area is larger than 49 mm² and located in the anterolateral or lateral column of the femoral head, the possibility of rapid collapse progression is high, therefore, monitoring should be strengthened and active intervention should be considered.

Outcome of tantalum rod insertion in the treatment of osteonecrosis of the femoral head with minimum follow-up of 1 year: a meta-analysis and systematic review

Osteonecrosis of the femoral head (ONFH) is a debilitating disease that can cause deformity and collapse of the femoral head, thus leading to the development of degenerative joint disease that can incapacitate the patient with pain and reduction in hip mobility. This study aims to determine the safety and efficacy of tantalum rod insertion in the treatment of ONFH with a minimum follow-up period of 1 year. A multi-database search was performed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Data from studies assessing the clinical and radiological outcomes as well as complications of tantalum rod insertion in the treatment of ONFH with a minimum follow-up period of 1 year were extracted and analyzed. Ten studies were included in this meta-analysis, consisting of 550 hips. There was a statistically significant increase in HHS (MD = 30.35, 95% CI: 20.60-40.10, P < 0.001) at final follow-up versus pre-operative scores. The weighted pooled proportion (PP) of radiographic progression of ONFH was 0.221 (95% CI: 0.148-0.316), while that of progression into femoral head collapse was 0.102 (95% CI: 0.062-0.162). Conversion to total hip arthroplasty (THA) had a PP of 0.158 (95% CI: 0.107-0.227) with a mean weighted period of 32.4 months (95% CI: 24.9-39.9 months). Subgroup analysis of conversion to THA when tantalum rods were used in conjunction with bone grafting (PP = 0.150, 95% CI: 0.092-0.235) showed a marginal risk reduction than when compared with subgroup analysis of tantalum rods being used alone (PP = 0.154, 95% CI: 0.078-0.282). Tantalum rod is a safe alternative option to the current joint-preserving procedures available in the treatment of ONFH. However, more studies are needed to investigate and identify the most appropriate patients who would benefit most and the synergistic effect brought on by the use of complementary biological augmentation of bone grafting or stem cells with tantalum rods.

Association between MTHFR C677T polymorphism and non-traumatic osteonecrosis of the femoral head: An update meta-analysis

Objective To investigate the correlation between MTHFR C677T polymorphism and non-traumatic osteonecrosis of the femoral head.

Methods Open published studies relevant to MTHFR C677T polymorphism and non-traumatic osteonecrosis of the femoral head were electronic systematic searched in the databases of cochrane central register of controlled trials, EMBSE and CNKI. The correlation between MTHFR C677T polymorphism and non-traumatic osteonecrosis of the femoral head was calculated by odds ratio (OR) and corresponding 95% confidence interval (95%CI). The publication bias for the included studies were assessed by Begg’s funnel plot and Egger’s line regression text.

Results After systematic searching the electronic databases, 11 original studies were finally included the present work. The I2 test indicated significant statistical heterogeneity (I2=53.5%, P=0.018) across the included 11 publications. The polled results indicated that subjects of Caucasians with CC genotype had decreased risk of developing non-traumatic osteonecrosis of the femoral head (OR=0.65,95%CI: 0.44-0.96, P=0.031). However, there was no correlations between MTHFR C677T polymorphism and non-traumatic osteonecrosis of the femoral head in American Jewish and East Asian races(p>0.05). Sensitivity analysis indicated the pooled ORs were not sensitive to any included single study. The Begg’s funnel plot was generally left and right symmetrical which indicated no obviously publications. The Egger’s line regression test also demonstrated no statistical publication bias (t=1.57, P=0.15).

Conclusion According to the present evidence, MTHFR C677T polymorphism was correlated with non-traumatic osteonecrosis of the femoral head especially for Caucasians race. Subjects of Caucasians race with CC genotype had decreased risk of developing non-traumatic osteonecrosis of the femoral head.

Three-dimensional distribution of cystic lesions in osteonecrosis of the femoral head

Purpose

The aim of this study was to investigate the location characteristics of cystic lesions in a three-dimensional context and discuss the mechanism of formation.

Methods

A total of 155 femoral head computed tomography images from 94 patients diagnosed with stage II and III osteonecrosis of the femoral head were retrospectively reviewed. Three-dimensional structures of the femoral head including the cystic lesions and necrotic area were reconstructed. We divided each femoral head into eight regions to observe the positional relationship of the cystic lesions, normal areas, and necrotic areas.

Results

The regional distribution revealed 14 (13%), 35 (32%), 9 (8%), 25 (23%), 6 (6%), 15 (14%), 4 (4%), and 0 (0%) cystic lesions in regions Ⅰ, Ⅱ, Ⅲ, Ⅳ, Ⅴ, Ⅵ, Ⅶ, and Ⅷ, respectively. The anteromedial zone, A (Ⅰ ​+ ​Ⅲ), contained 22% of the lesions, anterolateral zone, B (Ⅱ ​+ ​Ⅳ), contained 54%, posteromedial zone, C (Ⅴ +Ⅶ), contained 9% of the lesions, and posterolateral zone, D (Ⅵ ​+ ​Ⅷ), contained 15% of the lesions. Most of the cystic lesions (78%) were located between the normal and necrotic areas; 18% of cystic lesions were in the necrotic area ​and 4% were in the normal area.

Conclusions

Cystic lesions most often occur at the junction of the necrotic ​and normal areas and are most commonly located in the anterolateral femoral head, which is similar to the distribution of the stress concentration region.

The translational potential of this article

The study showed the location characteristics of cystic lesions in osteonecrosis of femoral head, which suggested that the formation of cystic lesions may be related to stress and could accelerate the collapse of femoral head. The results can support further research on cystic lesions and provide a reference for doctors' treatment strategies for patients with osteonecrosis of femoral head.

[Atraumatic and aseptic osteonecrosis of large joints]

Subchondral osteonecrosis of large weight-bearing joints (hip and knee joints) represents a severe and joint-threatening disease. Apart from idiopathic forms, glucocorticoid medication and alcohol abuse have been identified as major causative factors for atraumatic osteonecrosis. In addition to direct cytotoxic factors, a critically reduced perfusion of the subchondral osseous space will eventually lead to bone marrow ischemia and osseous necrosis. Magnetic resonance imaging (MRI) is capable of visualizing a reactive border-like zone in this early, already irreversible and often asymptomatic stage I according to the Association of Research Circulation Osseous (ARCO) staging system. Later in the course, osteonecrosis progresses to form serpiginous sclerotic lines, enclosing the necrotic bone area (stage II ARCO). Repair mechanisms of osteonecrosis are mostly unsuccessful and depending on the size of the osteonecrosis result in biomechanical failure and ultimately subchondral insufficiency fractures (crescent sign), thus marking the transition to stage III ARCO (joint surface collapse).