The natural history of untreated asymptomatic osteonecrosis of the femoral head: a systematic literature review

Evaluating blood supply changes in the osteonecrosis of the femoral head using gadobutrol-based steady-state MR angiography

OBJECTIVES

Assess the feasibility of using gadobutrol-based steady-state (SS) MR angiography (MRA) to evaluate the blood supply changes of osteonecrosis of the femoral head (ONFH).

MATERIALS AND METHODS

Participants were recruited in this prospective study from December 2021 to May 2022 in a single center. The number of superior retinacular arteries (SRAs), inferior retinacular arteries (IRAs), anterior retinacular arteries (ARAs), and overall retinacular arteries (ORAs), as well as the affected rates of SRA and IRA, were determined and compared between healthy and ONFH hips and between hips across the Association Research Circulation Osseous (ARCO) staging I-IV.

RESULTS

Twenty healthy and 64 ONFH hips were evaluated in 54 participants. There were significant differences between ARCO I-IV for the number of ORAs (mean of 3.5, 2.3, 1.7, and 0.8 for ARCO I-IV, respectively; p < .001), SRAs (median of 2.5, 1, 0.5, and 0 for ARCO I-IV, respectively; p < .001), and the affected rate of SRAs (20.00%, 65.22%, 77.78%, 92.31% for ARCO I-IV, respectively, p = 0.002). There were significant differences between ONFH and healthy hips for the number of ORAs (median of 5 vs. 2; p < .001), SRAs (median of 3 vs. 1; p < .001), IRAs (median of 1 vs. 1; p < .001), ARAs (median of 0 vs. 0; p = 0.04), and also the affected rate of SRAs (5.00% vs. 67.20%, p < .001) and IRAs (30% vs. 84.4%, p < .001).

CONCLUSION

Gadobutrol-enhanced SS MRA is a feasible method for evaluation of hemodynamics in ONFH.

CLINICAL RELEVANCE STATEMENT

Gadobutrol-enhanced magnetic resonance angiography can evaluate blood supply changes of ONFH and therefore helps to aid in the diagnosis and guide treatment of ONFH.

KEY POINTS

• Gadobutrol-enhanced magnetic resonance angiography showed changes in the retinacular artery related to the severity of femoral osteonecrosis. • Gadobutrol-enhanced magnetic resonance angiography revealed a reduced blood supply to the ischemic necrotic femoral head compared to the healthy counterparts.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Automatic detection of early osteonecrosis of the femoral head from various hip pathologies using deep convolutional neural network: a multi-centre study

PURPOSE

The aim of this study was to develop a deep convolutional neural network (DCNN) for detecting early osteonecrosis of the femoral head (ONFH) from various hip pathologies and evaluate the feasibility of its application.

METHODS

We retrospectively reviewed and annotated hip magnetic resonance imaging (MRI) of ONFH patients from four participated institutions and constructed a multi-centre dataset to develop the DCNN system. The diagnostic performance of the DCNN in the internal and external test datasets was calculated, including area under the receiver operating characteristic curve (AUROC), accuracy, precision, recall, and F1 score, and gradient-weighted class activation mapping (Grad-CAM) technique was used to visualize its decision-making process. In addition, a human-machine comparison trial was performed.

RESULTS

Overall, 11,730 hip MRI segments from 794 participants were used to develop and optimize the DCNN system. The AUROC, accuracy, and precision of the DCNN in internal test dataset were 0.97 (95% CI, 0.93-1.00), 96.6% (95% CI: 93.0-100%), and 97.6% (95% CI: 94.6-100%), and in external test dataset, they were 0.95 (95% CI, 0.91- 0.99), 95.2% (95% CI, 91.1-99.4%), and 95.7% (95% CI, 91.7-99.7%). Compared with attending orthopaedic surgeons, the DCNN showed superior diagnostic performance. The Grad-CAM demonstrated that the DCNN placed focus on the necrotic region.

CONCLUSION

Compared with clinician-led diagnoses, the developed DCNN system is more accurate in diagnosing early ONFH, avoiding empirical dependence and inter-reader variability. Our findings support the integration of deep learning systems into real clinical settings to assist orthopaedic surgeons in diagnosing early ONFH.

Efficacy of Modified Lightbulb Technique by Percutaneous Femoral Neck-Head Fenestration Combined With Compacted Artificial Bone Graft for Treating Precollapse Osteonecrosis of the Femoral Head

BACKGROUND

Whether artificial bone provides comparable outcomes to autogenous bone has not been determined for osteonecrosis of the femoral head (ONFH). This study was conducted to compare the clinical outcomes of autogenous and artificial bone grafting (demineralized bone matrix/calcium sulfate [DBM/CaS]) through a modified lightbulb technique by percutaneous femoral neck-head fenestration for treating precollapse ONFH.

METHODS

A total of 73 Association Research Circulation Osseous Stage Ⅱ ONFH patients (81 hips) who had a mean follow-up of 61 months (range, 52 to 74) were included in this retrospective study. Among them were 40 hips treated with autogenous bone and 41 hips treated with DBM/CaS grafting through the percutaneous femoral neck-head fenestration. The Harris scores, radiographic progressions, clinical success rates, and survival analyses were analyzed.

RESULTS

At final follow-up, the mean Harris score was 80 points (range, 63 to 92) in the DBM/CaS group and 76 points (range, 69 to 91) in the autogenous bone group (P = .751). The radiographic progression rate was 29.9% in the DBM/CaS group, without significant difference from the autogenous bone group, which was 37.5% (P = .43). About 73.2% of patients in the DBM/CaS group and 75% in the autologous bone group avoided a total hip arthroplasty (P = .85). Survival analysis for femoral head protection revealed similar outcomes between the 2 groups (P > .05).

CONCLUSION

Percutaneous femoral neck-head fenestration combined with artificial bone (DBM/CaS) grafting had comparable clinical outcomes to autologous bone grafting on preventing femoral head collapse and rescuing THA at a mean of 61-month follow-up for treating early ONFH.

Pyroptosis -related potential diagnostic biomarkers in steroid-induced osteonecrosis of the femoral head

PURPOSE

Steroid-induced necrosis of the femoral head (SONFH) is a refractory orthopedic hip disease occurring in young and middle-aged people, with glucocorticoids being the most common cause. Previous experimental studies have shown that cell pyroptosis may be involved in the pathological process of SONFH, but its pathogenesis in SONFH is still unclear. This study aims to screen and validate potential pyroptosis-related genes in SONFH diagnosis by bioinformatics analysis to further elucidate the mechanism of pyroptosis in SONFH.

METHODS

There were 33 pyroptosis-related genes obtained from the prior reviews. The mRNA expression was downloaded from GSE123568 dataset in the Gene Expression Omnibus (GEO) database, including 10 non-SONFH (following steroid administration) samples and 30 SONFH samples. The pyroptosis-related differentially expressed genes involved in SONFH were identified with "affy" and "limma" R package by intersecting the GSE123568 dataset with pyroptosis genes. In addition, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the pyroptosis-related differentially expressed genes involved in SONFH were conducted by "clusterProfiler" R package and visualized by "GOplot" R package. Then, the correlations between the expression levels of the pyroptosis-related differentially expressed genes involved in SONFH were confirmed with "corrplot" R package. Moreover, the protein-protein interaction (PPI) network was analysed by using GeneMANIA database. Next, The ROC curve of pyroptosis-related differentially expressed genes were analyzed by "pROC" R package.

RESULTS

A total of 10 pyroptosis-related differentially expressed genes were identified between the peripheral blood samples of SONFH patients and non-SONFH patients based on the defined criteria, including 20 upregulated genes and 10 downregulated genes. The GO and KEGG pathway enrichment analyses revealed that these 10 pyroptosis-related differentially expressed genes involved in SONFH were particularly enriched in cysteine-type endopeptidase activity involved in apoptotic process, positive regulation of interleukin-1 beta secretion and NOD-like receptor signaling pathway. Correlation analysis revealed significant correlations among the 10 differentially expressed pyroptosis-related genes involved in SONFH. The PPI results demonstrated that the 10 pyroptosis-related differentially expressed genes interacted with each other. Compared to non-SONFH samples, these pyroptosis-related differentially expressed genes had good predictive diagnostic efficacy (AUC = 1.000, CI = 1.000-1.000) in the SONFH samples, and NLRP1 had the highest diagnostic value (AUC: 0.953) in the SONFH samples.

CONCLUSIONS

There were 10 potential pyroptosis-related differentially expressed genes involved in SONFH were identified via bioinformatics analysis, which might serve as potential diagnostic biomarkers because they regulated pyroptosis. These results expand the understanding of SONFH associated with pyroptosis and provide new insights to further explore the mechanism of action and diagnosis of pyroptosis associated in SONFH.

Ex vivo study of detergent-assisted intraosseous bone wash treatment of osteonecrosis

Avascular necrosis (AVN) involves ischemic cell death of the bone. AVN leaves an abundance of necrotic lipids and debris in the bone marrow, which instigates inflammatory bone repair. Consequently, the necrotic bone microenvironment stimulates excessive bone resorption, leading to joint deformities and osteoarthritis. Here, we performed a detergent-assisted bone wash using poloxamer 407 (P407) to clean the necrotic bone environment by removing lipids and necrotic debris. The new concept was tested using an established ex vivo AVN model of porcine cadaver humeral heads. The P407 wash was performed using P407 solution and followed with saline via two intraosseous needles. Visual inspection and image analyses of average pixel light intensity showed that the P407 wash produced a better-cleaned bone than the saline wash. Analyses of the collected bone wash solution showed a two-fold increase in triglycerides (101 vs. 53 mmol/head, p = 0.006) and a 10-fold increase in the dry weight of the removed debris (1.34 vs. 0.13 g/head, p = 0.02) with the P407 wash compared to saline. The histological evaluation showed significantly decreased Oil-Red-O (fats) staining in the P407-washed bone compared with the saline-washed bone. The in vitro assays of Alizarin red and qPCR showed the P407 wash neither altered the osteogenic behaviors of porcine bone marrow-derived mesenchymal cells (pBMMCs) nor raised inflammatory responses of porcine bone marrow-derived macrophages (pBMMs). In conclusion, detergent-assisted bone wash using P407 produced a better removal of nonsoluble debris from the bone marrow space than the saline wash without causing changes to osteogenesis or inflammatory reactions.

Low miR-182-5p Expressing Extracellular Vesicles Derived From Human Bone Marrow Stromal Cells of Subjects With Steroid-Induced Osteonecrosis of the Femoral Head Aggravate Disease Progression

Steroid-induced osteonecrosis of the femoral head (SONFH) is a refractory, progressive disease. However, the underlying mechanisms that aggravate femoral head necrosis remain unclear. Extracellular vesicles (EVs) act as molecular carriers in intercellular communication. We hypothesize that EVs derived from human (h) bone marrow stromal cells (BMSC) resident in SONFH lesion areas promote the pathogenesis of SONFH. In the present study, we determined the modulatory effects of SONFH-hBMSCs-derived EVs on the pathogenesis of SONFH in vitro and in vivo. We found that the expression of hsa-miR-182-5p was downregulated in SONFH-hBMSCs and EVs isolated from those hBMSCs. After tail vein injection, EVs isolated from hBMSCs transfected with hsa-miR-182-5p inhibitor aggravated femoral head necrosis in the SONFH mouse model. We conclude that miR-182-5p regulates bone turnover in the SONFH mouse model via targeting MYD88 and subsequent upregulation of RUNX2 expression. We further assume that EVs derived from hBMSCs resident in SONFH lesion areas aggravate femoral head necrosis by downregulating miR-182-5p secreted from hBMSC located outside these lesions. We suggest that miR-182-5p could provide a novel target for future therapeutic approaches to treat or prevent SONFH. © 2023 American Society for Bone and Mineral Research (ASBMR).

Reliability and repeatability of 2021 ARCO classification and its guiding significance in treatment of nontraumatic osteonecrosis of the femoral head

BACKGROUND

The study was designed to evaluate the interobserver reliability and intraobserver repeatability of the 2021 Association Research Circulation Osseous (ARCO) classification and explore its guiding significance in the treatment of nontraumatic osteonecrosis of the femoral head (ONFH).

METHODS

In this retrospective study, we randomly selected and investigated 50 sets of preoperative computed tomography or magnetic resonance imaging scans from 96 patients (139 hips) to validate the reliability and repeatability of the 2021 ARCO classification. Patients with a nano-hydroxyapatite/polyamide-66 support rod were included in the clinical efficacy study. The Harris hip score (HHS) was used to assess hip function. Femoral head collapse of > 2 mm was considered radiological failure. Total hip arthroplasty (THA) was performed for clinical failure, and follow-up was discontinued.

RESULTS

The average kappa value of interobserver consistency was 0.652. The average rate of consistency was 90.25%, and the average kappa value of intraobserver consistency was 0.836. Eighty-two patients (122 hips) were enrolled and followed up for a mean of 43.57 ± 9.64 months. There was no significant difference in the HHS among the three groups before surgery, but the difference was statistically significant at the last follow-up. Among them, types 1 and 2 had significantly higher scores at the last follow-up than preoperatively (P < 0.05), whereas type 3 had a lower score at the last follow-up than preoperatively, although the difference was not statistically significant (P > 0.05).According to the imaging evaluation, the failure rate of type 1, 2, and 3 at the last follow-up was 0%, 19%, and 87%, respectively. Univariate analysis showed that the femoral head survival rate of radiography was significantly affected by the new classification system (P = 0.00). At the last follow-up, the incidence rate of THA in type 1, 2, and 3 was 5%, 7%, and 31%, respectively. Univariate analysis showed that the femoral head survival rate was significantly affected by the new classification system (P = 0.001).

CONCLUSIONS

The 2021 ARCO classification for early-stage ONFH shows substantial consistency and repeatability. We do not recommend femoral head-preserving surgery for patients with type 3 ONFH.

The Lnc-HOTAIR/miR122/PPARγ signaling mediated the occurrence and continuous development of alcohol-induced Osteonecrosis of the femoral head

This study aimed to explore the mechanism of alcohol-induced Osteonecrosis of the femoral head (ONFH) through in vivo and in vitro experiments. In vitro, the Oil Red O staining showed that ethanol promoted extracellular adipogenesis in a dose-dependent manner. ALP staining and alizarin red staining showed that ethanol inhibited the formation of extracellular mineralization in a dose-dependent manner. The Oil Red O staining showed that miR122 mimics and Lnc-HOTAIR SiRNA rescued extracellular adipogenesis induced by ethanol in BMSCs. Besides, we found that the high expression of PPARγ in BMSCs recruited histone deacetylase 3 (HDAC3) and histone methyltransferase (SUV39H1), which reduced the histone acetylation level and increased the histone methylation level in the miR122 promoter region, respectively. In vivo, the levels of H3K9ac, H3K14ac, and H3K27ac of miR122 promoter region in the ethanol group were significantly decreased compared to the control group, respectively. The levels of H3K9me2 and H3K9me3 of miR122 promoter region in the ethanol group were significantly increased compared to the control group. Lnc-HOTAIR/miR-122/PPARγ signaling mediated the alcohol-induced ONFH in the rat model. Furthermore, the persistent decrease of miR122 expression mediated the continuous progress of alcohol-induced ONFH after stopping alcohol consumption.

Metabolomic analysis of bone-derived exosomes in osteonecrosis of the femoral head based on UPLC-MS/MS

INTRODUCTION

Osteonecrosis of the femoral head (ONFH) is a disorder that causes a collapse of the femoral head, requiring subsequent total hip replacement. However, the pathogenesis of ONFH remains largely unclear. Herein, exosome metabolomics analyses were conducted to explore the pathophysiology of ONFH.

OBJECTIVES

This study aimed to conduct metabolic profiling of bone-derived exosomes of ONFH.

METHODS

30 ONFH patients and 30 femoral neck fracture (FNF) patients were included in this study. Exosomes were harvested from the femoral head by using ultracentrifugation. Ultraperformance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) was performed in combination with multivariate statistical analysis to reveal and provided new insight into identify the global metabolic profile of ONFH.

RESULTS

The results of transmission electron microscope (TEM), nanoparticle tracking analysis (NTA), and Western blots indicated that the microvesicles isolated from the femoral head were exosomes. Several compounds were identified, including lipids and lipid-like molecules, amino acids, peptides, organooxygen compounds. 44 differential metabolites were screened between ONFH and FNF patients. The up-and down-regulation of Riboflavin metabolism, Pantothenate and CoA biosynthesis, Glycerophospholipid metabolism, and Sphingolipid metabolism were associated with ONFH pathophysiology.

CONCLUSION

Our results suggest that metabolomics has huge prospects for elucidating pathophysiology of ONFH.

Bone tissue engineering for treating osteonecrosis of the femoral head

Osteonecrosis of the femoral head (ONFH) is a devastating and complicated disease with an unclear etiology. Femoral head-preserving surgeries have been devoted to delaying and hindering the collapse of the femoral head since their introduction in the last century. However, the isolated femoral head-preserving surgeries cannot prevent the natural progression of ONFH, and the combination of autogenous or allogeneic bone grafting often leads to many undesired complications. To tackle this dilemma, bone tissue engineering has been widely developed to compensate for the deficiencies of these surgeries. During the last decades, great progress has been made in ingenious bone tissue engineering for ONFH treatment. Herein, we comprehensively summarize the state-of-the-art progress made in bone tissue engineering for ONFH treatment. The definition, classification, etiology, diagnosis, and current treatments of ONFH are first described. Then, the recent progress in the development of various bone-repairing biomaterials, including bioceramics, natural polymers, synthetic polymers, and metals, for treating ONFH is presented. Thereafter, regenerative therapies for ONFH treatment are also discussed. Finally, we give some personal insights on the current challenges of these therapeutic strategies in the clinic and the future development of bone tissue engineering for ONFH treatment.

The indications for core decompression surgery in patients with ARCO stage I-II osteonecrosis of the femoral head: a new, comprehensive prediction system

BACKGROUND

Core decompression (CD) is considered the most popular treatment method for patients with Association Research Circulation Osseous (ARCO) stage I-II osteonecrosis of the femoral head (ONFH). However, the definitive indication for CD is currently not well established.

METHODS

This was a retrospective cohort study. Patients who were diagnosed with ARCO stage I-II ONFH and who underwent CD were included. According to the prognosis, the patients were divided into two groups: collapse of the femoral head after CD and noncollapse of the femoral head. Independent risk factors for the failure of CD treatment were identified. Subsequently, a new scoring system that included all these risk factors was built to help estimate the individual risk of CD failure in patients who were planning to undergo CD.

RESULTS

The study included 1537 hips after decompression surgery. The overall failure rate of CD surgery was 52.44%. Seven independent prognostic factors for failed CD surgery were identified, such as male sex (HR = 75.449; 95% confidence interval (CI), 42.863-132.807), Aetiology (Idiopathic HR = 2.762; 95% CI, 2.016-3.788, Steroid-induced HR = 2.543; 95% CI, 1.852-3.685), if the patient had a seated occupation (HR = 3.937; 95% CI, 2.712-5.716), age (HR = 1.045; 95% CI, 1.032-1.058), haemoglobin level (HR = 0.909; 95% CI, 0.897-0.922), disease duration (HR = 1.217; 95% CI, 1.169-1.267) and the combined necrosis angle (HR = 1.025; 95% CI, 1.022-1.028). The final scoring system included these seven risk factors, and the area under the curve of this scoring system was 0.935 (95% confidential interval = 0.922-0.948).

CONCLUSION

This new scoring system might provide evidence-based medical proof for determining whether a patient with ARCO stage I - II ONFH might benefit from CD surgery. This scoring system is crucial for making clinical decisions. Consequently, this scoring system is recommended before CD surgery, which could help determine the potential prognosis of patients.

Decreased serum MMP-9 levels in patients with nontraumatic osteonecrosis of the femoral head

BACKGROUND

Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinases-1 (TIMP-1) are involved in the pathological mechanism of osteonecrosis of the femoral head (ONFH). This study aimed to investigate the relationship of serum MMP-9, TIMP-1, and the MMP-9/TIMP-1 ratio with disease severity in patients with nontraumatic ONFH.

METHODS

Serum levels of MMP-9 and TIMP-1 among 102 nontraumatic ONFH patients and 96 healthy individuals were determined by enzyme-linked immunosorbent assay (ELISA). Imaging severity was determined using the FICAT classification system. The Harris hip score (HHS) and visual analogue scale (VAS) were used to evaluate clinical progress. The correlations of serum MMP-9 and TIMP-1 levels with imaging severity and clinical progress was evaluated statistically. The diagnostic value of MMP-9 for NONFH disease severity was evaluated by examining receiver operating characteristic (ROC) curves.

RESULTS

The serum MMP-9 levels and the MMP-9/TIMP-1 ratio were significantly increased in patients with ONFH compared to normal controls, and TIMP-1 levels did not differ between the two groups. Serum MMP-9 levels and the MMP-9/TIMP-1 ratio were positively correlated with FICAT stage and VAS and were negatively correlated with the HHS score. The ROC curve results indicated that MMP-9 could be used as a potential marker of nontraumatic ONFH imaging progression.

CONCLUSIONS

We hypothesize that increased MMP-9 expression and an imbalance in the MMP-9/TIMP-1 ratio play a role in the development of ONFH and are correlate with the severity of ONFH. The determination of MMP-9 can be a useful tool to assess the severity of the disease in patients with nontraumatic ONFH.

A Pilot Experiment to Measure the Initial Mechanical Stability of the Femoral Head Implant in a Cadaveric Model of Osteonecrosis of Femoral Head Involving up to 50% of the Remaining Femoral Head

Background and Objectives: Currently, only patients with osteonecrosis of the femoral head (ONFH), who had bone defects involving 30–33.3% of the remaining femoral head, are indicated in hip resurfacing arthroplasty (HRA). In an experimental cadaver model of ONFH involving up to 50% of the remaining femoral head, the initial stability of the femoral head implant (FHI) at the interface between the implant and the remaining femoral head was measured. Materials and Methods: The ten specimens and the remaining ten served as the experimental group and the control group, respectively. We examined the degree of the displacement of the FHI, the bonding strength between the FHI and the retained bone and that at the interface between the FHI and bone cement. Results: Changes in the degree of displacement at the final phase from the initial phase were calculated as 0.089 ± 0.036 mm in the experimental group and 0.083 ± 0.056 mm in the control group. However, this difference reached no statistical significance (p = 0.7789). Overall, there was an increase in the degree of displacement due to the loading stress, with increased loading cycles in both groups. In cycles of up to 6000 times, there was a steep increase. After cycles of 8000 times, however, there was a gradual increase. Moreover, in cycles of up to 8000 times, there was an increase in the difference in the degree of displacement due to the loading stress between the two groups. After cycles of 8000 times, however, such difference remained almost unchanged. Conclusions: In conclusion, orthopedic surgeons could consider performing the HRA in patients with ONFH where the bone defects involved up to 50% of the remaining femoral head, without involving the femoral head–neck junction in the anterior and superior area of the femoral head. However, more evidence-based studies are warranted to justify our results.

Revisiting prediction of collapse in hip osteonecrosis with artificial intelligence and machine learning: a new approach for quantifying and ranking the contribution and association of factors for collapse

PURPOSE

This study proposes machine learning to analyze the risk factors of the collapse in patients with non-traumatic hip osteonecrosis of the femoral head.

METHODS

We collected data of 900 consecutive patients (634 males) with bilateral (428) or unilateral non-traumatic osteonecrosis diagnosed before collapse (at stage I or stage II). The follow-up was average five years (3 to 8 years). A total of 50 variables related to the osteonecrosis were included in the study. The osteonecroses were randomly divided into a training set (80%) and a validation set (20%) with a similar percentage of hips with collapse in the two groups. Machine learning (ML) algorithms were trained with the selected variables. Performance was evaluated and the different factors (variables) for collapse were ranked with Shapley values. The primary outcome was prediction of occurrence of collapse from automated inventory systems.

RESULTS

In this series of patients, the accuracy with machine learning for predicting collapse within three years follow-up was 81.2%. Accuracies for predicting collapse within six to 12-24 months were 54.2%, 67.3%, and 71.2%, respectively, demonstrating that the accuracy is lower for a prevision in the short term than for the mid-term. Despite none of the risk-factors alone achieving statistical significance for prediction, the system allowed ranking the different variables for risk of collapse. The highest risk factors for collapse were sickle cell disease, liver, and cardiac transplantation treated with corticosteroids, osteonecrosis volume > 50% of the femoral head. Cancer (such as leukemia), alcohol abuse, lupus erythematosus, Crohn's disease, pemphigus vulgaris treated with corticosteroids, and osteonecrosis volume between 40 and 50% were medium risk factors for collapse. Familial cluster of collapse, HIV infection, chronic renal failure, nephrotic syndrome, and renal transplantation, when treated with corticosteroids, stage II, osteonecrosis volume between 30 and 40%, chemotherapy, hip pain with VAS > 6, and collapse progression on the contralateral side, were also significant but lowest risk factors. A heat map is proposed to illustrate the ranking of the combinations of the different variables. The highest risk of collapse is obtained with association of various risks factors.

CONCLUSION

This study, for the first time, demonstrated prediction of collapse and ranking of factors for collapse with a machine learning system. This study also shows that collapse is due to a multifactorial risk factors.

Rare Bi-focal Presentation of Avascular Necrosis of the Femoral Head: Successful Targeted Treatment as per the Diamond Concept and Review of the Literature

Avascular necrosis of the femoral head (AVNFH) is relatively infrequent, but if undiagnosed or untreated, it may result in significant functional disability, and due to severe ongoing pain, a total hip replacement (THR) may be necessitated. Most cases are associated with trauma, but a number of established risk factors exist. Diagnosis can be challenging but relies on clinical history, physical examination, and radiology. X-ray and MRI are used to stage avascular necrosis (AVN) lesions, which in turn influence management decisions. We present a male in his early 40s, diagnosed with a right-sided AVNFH (Ficat-Arlet stage I) five years previously at another centre. A number of risk factors were identified, such as chronic alcohol abuse, smoking, obesity, and Klinefelter's syndrome. A 'watch and wait' approach was adopted, which included advice on reducing risk factors and commencement on aspirin and alendronic acid. However, his pain had recently increased, resulting in a significant reduction in mobility and an increased reliance on opiates. MRI demonstrated progression to Ficat-Arlet stage II, and the appearance of an additional smaller, second lesion located more medially in the same femoral head. Due to his symptom severity, he was offered a THR. In view of his young age, he came to our tertiary referral centre for a second opinion. He elected for a simultaneous dual surgical decompression of both AVN lesions and biological stimulation for bone-guided regeneration. This involved the delivery of growth factor (bone morphogenetic protein), progenitor cells, and a scaffold/matrix. At 36 months post-operatively, he continued to have the full, pain-free weight-bearing functional capacity, with radiographic imaging demonstrating no residual AVN or femoral head structural collapse. This was a unique case of bi-focal femoral head lesions, treated successfully with decompressions and biological enhancement using the 'diamond concept' for bone repair. In similar situations, when salvage of the femoral head is the preferred treatment option, such a strategy should be considered in the surgeon's armamentarium.

Collapse-related bone changes at multidetector CT in ARCO 1-2 osteonecrotic femoral heads: correlation with clinical and MRI data

OBJECTIVE

To assess the frequency of collapse-related bone changes at multi-detector CT (MDCT) in osteonecrotic femoral heads (ONFH) and to compare clinical parameters and MRI findings in Association Research Circulation Osseous (ARCO) 1-2 ONFH with or without collapse-related bone changes (CRBC) at MDCT.

MATERIALS AND METHODS

This is a secondary analysis of radiographic, MRI, and MDCT examinations of ONFH of patients eligible for a prospective clinical trial. Radiographs and MRI were analyzed to perform ARCO staging. Frequency of CRBC at MDCT including cortical interruption, trabecular interruption, impaction, and resorption was determined by two readers (R1, R2) blinded to radiographic, MRI, and clinical data. Baseline clinical and imaging data of ARCO 1-2 ONFH were compared between hips with or without CRBC at MDCT.

RESULTS

One hundred thirty-two hips of 77 participants were analyzed. There were 78 non-collapsed and 54 collapsed ONFH. For R1 and R2, 31/78 (40%) and 20/78 (26%) ARCO 1-2 ONFH and 54/54 (100%) and 53/54 (98%) ARCO 3-4 ONFH showed at least one CRBC at MDCT. For both readers, there was no significant difference in pain, functional impairment, size of lesion, and the presence of BME on MRI between ARCO 1-2 hips with or without CRBC at MDCT.

CONCLUSION

Twenty-six to forty percent of ARCO 1-2 ONFH demonstrate at least one collapse-related bone change at CT. Their clinical and MRI findings do not differ from those without collapse-related bone changes.

KEY POINTS

• Ninety-eight to one hundred percent of collapsed and 26-40% of non-collapsed osteonecrotic femoral heads presented at least one collapse-related bone change at CT (cortical or trabecular bone interruption, trabecular bone impaction, or resorption). • There was no significant difference in age, sex, pain, functional impairment, size of lesion, or frequency of marrow edema on MRI between non-collapsed hips with or without collapse-related bone changes at CT. • The significance of collapse-related bone changes at CT should be further assessed.

Core decompression with β-tri-calcium phosphate grafts in combination with platelet-rich plasma for the treatment of avascular necrosis of femoral head

BACKGROUND

This study was aimed to investigate whether the application of platelet-rich plasma (PRP) combined with β-tri-calcium phosphate (β-TCP) grafts after core decompression (CD) could improve the clinical outcomes of early stage of avascular necrosis of femoral head.

METHODS

Forty-five (54 hips) patients with Ficat-Arlet classification stage I-II treated by CD with β-TCP grafts with or without the application of PRP from July 2015 to October 2020 were reviewed. Group A (CD + β-TCP grafts) included 24 patients (29 hips), while group B (CD + β-TCP grafts + PRP) included 21 patients (25 hips). Visual analogue scale (VAS) score, Harris hip score (HHS), change in modified Kerboul angle and the hip joint survival were evaluated and compared between the groups. Patients had a mean follow-up period of 62.1 ± 17.2 months and 59.3 ± 14.8 months in group A and group B, respectively.

RESULTS

The mean VAS scores in group A was significantly higher than group B at the 6 months (2.9 ± 0.7 vs 1.9 ± 0.6, p < 0.01) and final follow up postoperative (2.8 ± 1.2 vs 2.2 ± 0.7, p = 0.04). The mean HHS in group A was significantly lower than group B at the 6 months (80.5 ± 13.8 vs 89.8 ± 12.8, p = 0.02). However, at the final follow up, there is no significant difference between the groups (77.0 ± 12.4 vs 83.1 ± 9.3, p = 0.07). The mean change in modified Kerboul angle was -7.4 ± 10.6 in group A and -19.9 ± 13.9 in group B which is statistically significant (p < 0.01). Survivorship from total hip arthroplasty were 86.2%/84% (p = 0.86) at the final follow up, which was not statistically significant. No serious complications were found in both groups.

CONCLUSIONS

A single dose of PRP combined with CD and β-TCP grafts provided significant pain relief, better functional outcomes, and delayed progression in the short term compared to CD combined with β-TCP grafts. However, the prognosis of the femoral head did not improve significantly in the long term. In the future, designing new implants to achieve multiple PRP injections may improve the hip preservation rate.

Familial Thrombophilia Is Associated With Primary Multifocal Osteonecrosis: A Case-Control Study of 40 Patients

To characterize pathoetiologic associations of heritable thrombophilia-hypofibrinolysis with idiopathic (primary) multifocal osteonecrosis (ON) (≥3 ON anatomic sites), we prospectively studied 28 women and 12 men with primary multifocal ON compared with 27 women and 24 men with primary nonmultifocal ON (<3 sites) and 110 healthy controls without ON. The 40 cases with primary multifocal ON differed from controls for 3 familial thrombophilias: Factor V Leiden heterozygosity (6 of 40 [15%] vs 2 of 109 [2%], P=.002), G20210A prothrombin gene heterozygosity (6 of 40 [15%] vs 3 of 110 [3%], P=.011), and high (>150%) Factor VIII (8 of 40 [20%] vs 7 of 103 [7%], P=.031). These case-control familial coagulation differences paralleled those in 51 concurrently evaluated cases with primary nonmulti-focal ON, 7 of 51 (14%) of whom had Factor V Leiden heterozygosity vs 2% of controls (P=.005) and 14 of 44 (32%) of whom had high Factor VIII vs 7 of 103 (7%) of controls (P=.0002). Recognition of familial thrombophilia as a common pathoetiology of primary multifocal ON provides an opportunity for early anticoagulation (before joint collapse), allowing both prophylaxis and therapy aimed at relieving pain and slowing or stopping progression of the disease to joint collapse. [Orthopedics. 202X;XX(X):xx-xx.].

Hip function in patients undergoing conservative treatment for osteonecrosis of the femoral head

PURPOSE

Once collapsed, osteonecrosis of the femoral head (ONFH) generally obtains collapse cessation naturally and surgical intervention can be avoided in the long term. This study aimed to investigate the process of hip function and secondary osteoarthritis changes in ONFH patients undergoing conservative treatment.

METHODS

We included 54 patients with symptomatic ONFH at the first visit with a minimum follow-up of three years with conservative treatment. Patients were divided into two groups based on collapse cessation < 3 mm (stable group) or progression to > 3 mm (progression group). Additionally, we investigated age, sex, body mass index (BMI), etiology, contralateral side hip joint, the Japanese Investigation Committee (JIC) type classification, Harris hip score (HHS), Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ), and survival rate with secondary osteoarthritis as the endpoint.

RESULTS

The stable and progression groups had 31 and 23 patients, respectively. No significant differences in age, sex, BMI, and aetiology were observed between the two groups, except for the contralateral side hip joint and JIC type classification. The HHS and JHEQ were significantly improved at the final follow-up than at the first visit in the stable group. However, there were no significant differences in HHS and JHEQ at the final follow-up than at the first visit in the progression group. The five year survival rates with secondary osteoarthritis as the endpoint were significantly higher in the stable group (100%) than in the progression group (32.5%).

CONCLUSION

Hip joint function improved by continuing conservative treatment in ONFH patients with collapse cessation < 3 mm.

Comparison of current treatment strategy for osteonecrosis of the femoral head from the perspective of cell therapy

Aims: The purpose of our study is to compare the effects of core decompression (CD) and bone grafting (BG) on osteonecrosis of the femoral head (ONFH). And evaluate the efficacy of CD based on cell therapy to provide guidance for the dose and number of cells. Methods: We searched PubMed, Embase, and the Cochrane Library between 2012 and 2022, with keywords including "osteonecrosis of the femoral head", "core decompression" and "bone grafting". We selected comparative studies of CD and BG, and the comparison of CD combined with bone marrow (BM) transplantation and CD alone. Changes in hip pain were assessed by VAS, hip function were assessed by HHS and WOMAC, and THA conversion rate was used as an evaluation tool for femoral head collapse. From these three aspects, the dose of bone marrow and the number of cells transplantation were subgroup analyzed. Results: Eleven studies were used to compare the efficacy of CD and BG. There was no significant difference in HHS, and the THA conversion rate of BG was significantly lower than that of CD. Thirteen CD studies based on cell therapy were included in the meta-analysis. Bone marrow aspiration concentrate (BMAC) can significantly improve VAS (mean difference (MD), 10.15; 95% confidence intervals (CI) 7.35 to 12.96, p < 0.00001) and reduce THA conversion rate (odds ratio (OR), 2.38; 95% CI 1.26 to 4.47, p = 0.007). Medium dose bone marrow fluid has a lower p-value in THA conversion rate. The p values of bone marrow mononuclear cells (BMMC) of 10⁹ magnitude in VAS score were lower. Conclusion: In general, there is no consensus on the use of BG in the treatment of ONFH. The enhancement of cell-based CD procedure shows promising results. Using 20 mL BMAC and 10⁹ magnitude BMMC is likely to achieve better results.

[Expert consensus on clinical diagnosis and treatment technique of osteonecrosis of the femoral head (2022 version)]

Osteonecrosis of the femoral head (ONFH) is a common and refractory disease in the clinic. Although the exact pathophysiological mechanism is not fully understood, it is believed to be closely related to the interruption of intra-bone circulation and eventual bone tissue death. The prevention and treatment of ONFH is always a great challenge for orthopedists. The diagnostic level of ONFH has been continuously improved with the development of imaging techniques such as MRI and the in-depth understanding of the disease in recent years.There are many treatment methods for ONFH, which are generally considered individually and comprehensively according to factors such as the patient's age, osteonecrosis stage, classification, and compliance with joint-sparing treatment. There is currently no unified standard. ONFH staging and classification play an important reference value for doctors to choose treatment options. In recent years, based on the characteristics of ONFH in Chinese people, the academic community has proposed Chinese staging and China-Japan Friendship Hospital (CJFH) classification. The consensus also introduces them together with the international Association Research Circulation Osseous (ARCO) staging to provide guidance for individualized treatment of ONFH. In order to further standardize the diagnosis of ONFH and expand the treatment of ONFH, the Association Related to Circulation Osseous, Chinese Microcirculation Society (CSM-ARCO) organized domestic experts in the field of ONFH to jointly formulate the expert consensus, in order to provide reference for the standardized diagnosis of ONFH and the selection of individualized diagnosis and treatment techniques.

The influence of bone marrow edema for the assessment of the boundaries of necrotic lesions in patients with osteonecrosis of the femoral head

This study aimed to investigate the influence of bone marrow edema (BME) for the assessment of the boundaries of necrotic lesions using unenhanced and contrast-enhanced (CE) magnetic resonance (MR) images in patients with osteonecrosis of the femoral head (ONFH). We retrospectively reviewed 72 consecutive hips in 55 patients of ONFH that were Association Research Circulation Osseous (ARCO) stage III or higher and underwent both unenhanced and contrast-enhanced MR imaging between January 2005 and February 2016. The degree of extension of BMEs, and the boundaries of the necrotic lesions were compared using unenhanced and CE MR images on both mid coronal and mid oblique-axial slices. Forty-two percent of the coronal T1 images, 40% of the coronal fat-saturated T2 images, and 48% of the oblique-axial T1 images showed differences in the boundaries of necrotic lesion, by comparison with those of CET1-weighted MR images. The boundaries of necrotic lesions were clearly detected in all hips on CE coronal slices and 97% of all hips on CE oblique-axial slices. The BME grade in the difference group was significantly higher than in the non-difference group on the coronal plane (P = 0.0058). There were significant differences between the BME grade and duration from the onset of hip pain to MR imaging examination. Multivariate analyses revealed that the duration from the onset to MR imaging examination in both coronal (P = 0.0008) and oblique-axial slices (P = 0.0143) were independently associated with differences in the boundary of necrotic lesion between T1 and CET1-weighted MR images. Our findings suggest that unenhanced MR image may be insufficient for a precise assessment of the boundaries of the necrotic lesions for ONFH cases in the early phase of subchondral collapse due to the diffuse BME.

Posterior Pelvic Tilt in the Standing Position Might Be Associated with Collapse Progression in Post-Collapse Stage Osteonecrosis of the Femoral Head

OBJECTIVE

Excessive pelvic tilt has been reported to impair the biomechanical loading of the hip joint. However, the influence of pelvic tilt in osteonecrosis of the femoral head (ONFH) remains unclear. This study aims to assess whether sagittal pelvic posture in the standing position correlates with progression of femoral head collapse in post-collapse stage ONFH.

METHODS

This is a single-center retrospective study. We investigated 107 patients (107 hips; 73 males and 34 females; mean age, 48 years) diagnosed with Association of Research Circulation Osseous (ARCO) stage III ONFH at the first visit and who subsequently underwent surgical treatment in our institution from July 2016 to December 2020. The sagittal pelvic posture in the standing position before surgery was quantified as the angle formed by the anterior pelvic plane and the vertical z-axis in the sagittal view (APP angle). An APP angle <0° indicated posterior pelvic tilt. Progression of femoral head collapse was calculated as collapse speed. The following factors potentially associated with collapse speed were evaluated by exploratory data analysis followed with multiple linear regression analysis: sex, age, BMI, etiology, pelvic incidence, contralateral hip condition, time interval between the first visit and surgery, size of necrotic lesion, location of necrotic lesion, and APP angle.

RESULTS

As ONFH progressed from ARCO stage IIIA to stage IV, APP angle decreased significantly and continuously (stage IIIA, -0.2° ± 5.5°; stage IIIB, -3.7° ± 5.8°; stage IV, -7.1° ± 6.4°). The factors significantly associated with collapse speed were size of necrotic lesion (p = 0.0079), location of necrotic lesion (p = 0.0190), and APP angle (p < 0.0001). APP angle showed a negative correlation with collapse speed (r = -0.40, p < 0.0001). After stratifying by size of necrotic lesion (<50% and ≥50% involvement) and location of necrotic lesion (JIC type C1 and C2), a significant negative correlation was observed between APP angle and collapse speed in each group (JIC type C1 with <50% involvement, r = -0.69, p < 0.0001; JIC type C1 with ≥50% involvement, r = -0.58, p = 0.0475; JIC type C2 with <50% involvement, r = -0.51, p = 0.0124; JIC type C2 with ≥50% involvement, r = -0.39, p = 0.0286).

CONCLUSIONS

Our results suggest that posterior pelvic tilt in the standing position occurred as ONFH progressed from ARCO stage IIIA to stage IV, which might be associated with progression of femoral head collapse in ONFH.

[Short hip stem for THA in avascular necrosis of the femoral head]

INTRODUCTION

Osteonecrosis of the femoral head or avascular necrosis of the femoral head (HKN) is a complex disease that, without treatment, leads to infraction of the femoral head in most cases. In these cases, only replacement of the hip joint will help, although there is no clear recommendation of an arthroplasty type. In the last two decades, the treatment of primary and secondary coxarthrosis with short-shaft prostheses with different anchoring philosophies has increased. Since short-shaft fitting is a possible option especially in younger patients, the question arises about possible fittings of advanced HKN with these stem types, especially with metaphyseal anchorage. The aim of this study was to review the existing literature on the results of short stem prosthesis in HKN and to present the advantages and disadvantages of short stem prosthesis in osteonecrosis of the femoral head.

MATERIAL AND METHODS

This review analyzes the existing studies on short stem arthroplasty for HKN.

RESULTS

Only a few studies exist that have analyzed clinical and radiologic outcomes of short stem replacement in HKN.

CONCLUSION

The existing short- and medium-term results show mostly good outcomes. However, it is difficult to draw a general conclusion due to differences in stem design and fixation. Short stems with primary diaphyseal fixation do not show an increased risk of failed osseointegration or loosening. Constructions with primary metaphyseal fixation should undergo MRI to rule out the possibility of necrosis extending beyond the femoral neck.

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.

Effect of trochanter displacement on impingement and bone contact in total hip arthroplasty performed after curved intertrochanteric varus osteotomy for osteonecrosis of the femoral head: a simulation study

Background

Curved intertrochanteric varus osteotomy (CVO) is a useful treatment option for osteonecrosis of the femoral head (ONFH). However, the effect of proximal femoral deformity in cases of CVO converted to total hip arthroplasty (THA) remains unclear. The aim of this study was to evaluate the effect of trochanter displacement on impingement and the contact state of the implant and femur in THA.

Methods

Thirty-eight hips that had undergone CVO for ONFH were reviewed and compared with a control group of 30 contralateral hips that had not undergone surgery. The range of motion (ROM) and impingement patterns and the percentage of cortical bone in the stem placement within the femur were measured by simulation using CT-based three-dimensional template software. We also measured the ROM and the number of joints that achieved the ROM required for activities of daily living when the upward displaced apex of the greater trochanter with osteotomy was resected and compared the findings with those obtained when the apex was not resected.

Results

The CVO group showed a significantly greater bony impingement in external rotation (68.4% vs. 43.3%, p = 0.033) and abduction (78.9% vs. 33.3%, p < 0.001) than in the control group. The CVO group showed a significantly smaller range of external rotation (19.0° [interquartile range; 4.0–28.8] vs. 38.0° [interquartile range; 36.0–41.8], p < 0.001) and abduction (23.0° [interquartile range; 8.5–38.8] vs. 56.0° [interquartile range; 50.3–60.0], p < 0.001) than in the control group. Significantly more joints achieved the ROM necessary for activities of daily living when the apex was resected than when it was not (10.5% vs. 63.2%, p < 0.001). The percentage of cortical bone in the stem placement position was significantly higher in the CVO group than in the control group in the proximal portion of the stem (25.5% vs. 0.0%, p < 0.001).

Conclusion

In cases requiring conversion to THA, we recommend resecting the upward displaced apex to achieve a sufficient ROM and carefully resecting the bone to avoid malignment of the stem.

Borderline Developmental Dysplasia of the Hip: A Risk Factor Predicting the Development and Poor Prognosis after Core Decompression for Idiopathic Osteonecrosis of the Femoral Head

OBJECTIVE

It is unclear whether idiopathic osteonecrosis of the femoral head (ONFH) is associated with borderline developmental dysplasia of the hip (BDDH). This study aimed to compare the incidence of BDDH between patients with idiopathic ONFH and matched control subjects and determine the influence of BDDH on poor prognosis after core decompression (CD).

METHODS

We retrospectively examined 78 consecutive patients (111 hips) with idiopathic ONFH undergoing CD and 1:2 matched with 156 control subjects (222 hips). The anteroposterior pelvic radiographs were used to measure the acetabular anatomical parameters and divide included subjects into BDDH or non-BDDH group. The incidence of BDDH and acetabular anatomical parameters were compared between patients with idiopathic ONFH and matched controls. Clinical outcomes, such as Harris Hip Score (HHS), progression of collapse, and conversion to total hip arthroplasty (THA), were compared between patients with BDDH and without BDDH in the idiopathic ONFH group, with a mean follow-up of 72.1 ± 36.6 months.

RESULTS

Patients with idiopathic ONFH had a significantly higher incidence of BDDH than matched controls (29.7% vs 12.2%, p < 0.001). Less acetabular coverage was also found in patients with idiopathic ONFH than in matched controls as demonstrated by lower CEA (28.5° ± 4.7° vs 33.1° ± 5.7°, p < 0.001), AHI (82.4 ± 5.0 vs 86.3 ± 5.4, p < 0.001), ADR (299.6 ± 28.4 vs 318.8 ± 31.3, p < 0.001), and a higher sharp angle (40.0° ± 3.4° vs 37.4° ± 3.7°, p < 0.001). In patients with idiopathic ONFH, the BDDH group had a significantly lower mean HHS at the last follow-up (83.5 ± 17.4 vs 91.6 ± 9.7, p = 0.015) with a different score distribution (p = 0.004), and a lower 5-year survival rate with both clinical failure (66.7%, 95% CI 52.4%-84.9% vs 83.7%, 95% CI 75.2%-93.1%; p = 0.028) and conversion to THA (74.6%, 95% CI 60.7%-91.6% vs 92.1%, 95% CI 85.6%-99.0%; p = 0.008) as the endpoints than the non-BDDH group.

CONCLUSION

The incidence of BDDH was significantly higher in patients with idiopathic ONFH than matched controls, and idiopathic ONFH patients who underwent CD with BDDH had lower mean HHS as well as 5-year survival rate than those without BDDH. Therefore, BDDH should be considered a risk factor predicting the development of idiopathic ONFH as well as poor prognosis after CD.

Imbalanced T-Cell Subsets May Facilitate the Occurrence of Osteonecrosis of the Femoral Head

Background

Osteonecrosis of the femoral head (ONFH) is a complex disease resulting in degeneration of the hip joint. The pathogenesis of ONFH is largely unknown, but alterations in immunological factors have been proposed to play a role.

Methods

We included 109 patients with ONFH and 109 age-, sex-, and body mass index-matched healthy controls in this study. The percentage of circulating CD3+, CD4+, and CD8+ lymphocytes among the total lymphocytes was identified by flow cytometry and compared between the cases and controls. Subgroup analysis within each etiological group and correlation analysis of T-cell subset levels with disease duration were performed. Furthermore, we compared the expression patterns of CD4, RANKL, and FoxP3 in the femoral head of healthy and glucocorticoid (GC)-treated ONFH rats.

Results

The results showed that CD3+ and CD4+ T-cell counts and the CD4+/CD8+ ratio were significantly higher in patients with ONFH and that CD3+ lymphocyte levels were negatively correlated with disease duration. The CD4+ T-cell levels and CD4+/CD8+ ratios in the GC-ONFH etiological group were lower than those in the idiopathic-, traumatic-, and alcoholic-ONFH groups, while the CD8+ T-cell levels were higher. Furthermore, the CD3+, CD4+, and CD8+ T-cell counts and the CD4+/CD8+ ratio were higher in the GC-ONFH group than in the control group. Finally, we observed diminished levels of FoxP3/CD4 double-positive T regulatory cells and increased RANKL+ T-cell levels in the bone marrow of the femoral head in GC-ONFH rats.

Conclusion

The imbalance of T-cell subsets might be involved in the pathophysiological process of ONFH, and diminished CD4+/FoxP3+ T regulatory cells may be associated with increased RANKL+ T cells in the bone marrow of the femoral head in GC-ONFH, which may facilitate bone resorption and collapse of the femoral head.

Trial Registration

This study was registered in the Chinese Clinical Trial Registry (Registration number: ChiCTR2100042642).

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

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

Osteonecrose da cabeça femoral: Artigo de atualização

Among the pathologies that affect the hip joint, osteonecrosis of the femoral head (ONFH) is probably the most intriguing and challenging. It consists of a multifactorial disease with a highly-variable spectrum in its clinical presentation. It has a devastating effect, due to disabling painful conditions, both for usual activities and sports. Given the huge range of risk factors, such as prolonged use of corticosteroids (especially in cases of rheumatologic diseases), trauma sequelae, sickle cell anemia, HIV, alcoholism, smoking, blood dyscrasias, and several other diseases that compromise the blood supply to the femoral head, ONFH has a varied clinical presentation and prognosis, which makes it difficult to determine a specific treatment, especially in cases in which chondral involvement has not yet occurred and the hip joint is still preserved. These are the main factors found in the literature that determine the classifications of this pathology. The range of treatments includes several options for cases in which an attempt is made to save the joint: conservative treatment, traditional decompression and/or combined with some type of adjuvant treatment (homologous grafting, synthetic grafting, vascularized grafts, tantalum screws, and bone marrow aspirate injection), and, for cases in which there is already a subchondral fracture and/or collapse of the femoral head and/or a reduction in the joint space, femoral osteotomies or total hip arthroplasty are commonly performed.

Treatment of non-traumatic avascular necrosis of the femoral head (Review)

Non-traumatic osteonecrosis of the femoral head is the main cause of disability in young individuals and incurs major health care expenditure. The lifestyle changes in recent years, especially increased use of hormones and alcohol consumption, has greatly increased the incidence of femoral head necrosis. The underlying causes and risk factors of osteonecrosis of the femoral head are increasingly being elucidated, which has led to the development of novel surgical and non-surgical treatment options. Although the main goal of any treatment method is prevention and delaying the progression of disease, there is no common consensus on the most suitable method of treatment. The present review discussed the latest developments in the etiology and treatment methods for femoral head necrosis.

Comparison Between Concentrated Autologous Bone Marrow Aspirate Transplantation as a Hip Preserving Surgery and Natural Course in Idiopathic Osteonecrosis of the Femoral Head

Purpose The purpose is to compare the therapeutic efficacy of concentrated autologous bone marrow aspirate transplantation (CABMAT) with that of observation alone for osteonecrosis of the femoral head (ONFH). Methods This single-center study included patients with idiopathic ONFH that were either treated with CABMAT (CABMAT group) or managed through observation alone (observation group) over a >2-year follow-up period. The Japanese Investigation Committee classification was used to diagnose and classify ONFH. The collapse rates for stages 1 and 2 ONFH (i.e., pre-collapse stages) and the THA conversion rates were compared between the CABMAT and observation groups. Results The CABMAT and observation groups comprised 232 (mean follow-up: 8.2 years) and 106 (mean follow-up: 6.0 years) patients, respectively. No significant intergroup differences were noted in the stages, types, and associated factors of ONFH. The collapse rates for pre-collapse stages in the CABMAT and observation groups were 67.1% and 65.3%, respectively. For stage 1, the collapse rates were significantly lower in the observation group than in the CABMAT group (p<0.05). The overall THA conversion rates in the CABMAT and observation groups were 24.3% and 41.5%, respectively (p<0.0001). For ONFH of stages 3A and 3B (collapse stages), the THA conversion rates were significantly lower in the CABMAT group (p<0.05). Conclusion Collapse rates were significantly higher for stage 1 ONFH; for collapse stages, the THA conversion rates were significantly lower in the CABMAT group than in the observation group. Therefore, observation and CABMAT are recommended for ONFH of stage 1 and for ONFH of higher stages, respectively.

Predicting Collapse in Osteonecrosis of the Femoral Head Using a New Method: Preserved Angles of Anterior and Lateral Femoral Head

BACKGROUND

Femoral head collapse (FHC) is associated with a poor prognosis in osteonecrosis of the femoral head (ONFH). Preserved angles (PAs), including the lateral preserved angle (LPA), the anterior preserved angle (APA) and the combined preserved angle (CPA), can be used to quantify the extent of femoral head necrosis and predict the risk of femoral head collapse. The purpose of this retrospective cohort study was to assess the efficacy of these preserved angles in the prediction of femoral head collapse using plain radiographs.

METHODS

Patients with ONFH treated conservatively between January 2010 and January 2019 were analyzed retrospectively to assess the risk of FHC. A logistic regression model was used to evaluate the independent prognostic factors associated with FHC, including age, sex, etiology, onset of symptom, The Japanese Investigation Committee classification, and PAs (LPA, APA, and CPA).

RESULTS

A total of 137 patients, with 180 hips, had follow-up of at least two years and were included. During the follow-up period, FHC occurred in 89 hips (49.44%) after the initial diagnosis. Multivariable analysis indicated that CPA (odds ratio [OR] = 0.95; 95%CI = 0.93-0.97; P < 0.01) was a stronger predictor of femoral head collapse compared with the Japanese Investigation Committee classification (OR = 2.40, 95%CI = 0.92-6.25; P > 0.01). The receiver operating characteristic and survival curve analyses revealed that the predictive cutoff point for the CPA was 118.7° (sensitivity = 96.70%, specificity = 79.78%, log-rank test: P < 0.01).

CONCLUSIONS

Assessment of preserved angles on plain radiographs is a simple method to quantify the extent of lateral and anterior necrosis of the femoral head. Specifically, CPA has a potential value in predicting femoral head collapse.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

3.

Reliability and Repeatability of the China-Japan Friendship Hospital Typing Classification for Nontraumatic Osteonecrosis of the Femoral Head

BACKGROUND

The purpose of this study was to analyze the interobserver reliability and intraobserver repeatability of the China-Japan Friendship Hospital (CJFH) typing classification system for nontraumatic osteonecrosis of the femoral head (ONFH).

METHODS

Image data of 50 hips were randomly selected in 289 patients (433 hips) with ONFH who underwent treatment in the China-Japan Friendship Hospital from 2012 to 2016. Bilateral hip plain radiography, magnetic resonance imaging (MRI), or computerized tomography (CT) were performed in all hips. The assessments were performed by 8 new residents independently, and the repeatability was assessed at 4-week intervals. Evaluation indicators included the size, location, and extent of necrotic lesions. Kappa values were used to determine the reliability and repeatability.

RESULTS

According to the CJFH classification system, 2,800 evaluations were performed with an average interobserver Kappa value of 0.711, and 400 assessments were performed with an average intraobserver Kappa value of 0.748. Reliability analysis indicated a higher reliability and repeatability of this classification system. Critical factors affecting the consistency included the accurate selection of the median coronal plane and definitive tri-pillar division of the femoral head.

CONCLUSION

The CJFH classification system is a simple and direct evaluation model for ONFH with substantial inter- and intraobserver reliability.

Hip joint mechanics in patients with osteonecrosis of the femoral head following treatment by advanced core decompression

BACKGROUND

Osteonecrosis of the femoral head is a serious disease which, if left untreated, leads to destruction of the affected hip joint. For treatment of early stages of this disease, core decompression is the most common procedure. This study investigated the influence of the necrotic lesion and core decompression on the stress pattern in the hip joint using finite element analysis.

METHODS

Subject-specific models were generated from CT scan data of 5 intact hips. For each intact hip, twelve affected hip models were created by imposing a necrotic lesion in the femoral head, and four treated models were then created from four affected ones with central lesion, respectively. Treated models were created by supposing that the defect zone and the drill canal were filled with a bone substitute. Totally 105 hip models from three groups (intact, affected and treated) were simulated during normal walking activity.

FINDINGS

Necrotic lesion modified the stress distribution within the femoral head. Peak stress increased significantly up to 186% in mean in hips with a large lesion indicating an increased risk of femoral head collapse. Additionally, the presence of a medium to large necrosis altered significantly stress values (P < 0.05) and pattern in the articular cartilage. Our study revealed that advanced core decompression can recover normal cartilage stress values and pattern in treated joint.

INTERPRETATION

The presence of a large lesion increased the risk of femoral head collapse. Advanced core decompression with bone grafts can restore normal cartilage mechanics in hip postoperatively.

Knowledge structure and emerging trends on osteonecrosis of the femoral head: a bibliometric and visualized study

Background

Osteonecrosis of the femoral head (ONFH) is a common disabling disease with considerable social and economic impacts. Although extensive studies related to ONFH have been conducted in recent years, a specific bibliometric analysis on this topic has not yet been performed. Our study attempted to summarize the comprehensive knowledge map, development landscape, and future directions of ONFH research with the bibliometric approach.

Methods

All publications concerning ONFH published from 2001 to 2020 were identified from Web of Science Core Collection. Key bibliometric indicators were calculated and evaluated using CiteSpace, VOSviewer, and the online bibliometric analysis platform.

Results

A total of 2594 publications were included. Our analysis revealed a significant exponential growth trend in the annual number of publications over the past 20 years (R² = 0.9663). China, the USA, and Japan were the major contributors both from the quality and quantity points of view. Correlation analysis indicated that there was a high positive correlation between the number of publications and gross domestic product (r = 0.774), and a moderate positive correlation between publications and demographic factor (r = 0.673). All keywords were categorized into four clusters including Cluster 1 (etiology and risk factors study); Cluster 2 (basic research and stem cell therapy); cluster 3 (hip-preserving study); and Cluster 4 (hip replacement study). Stem cell therapy-related research has been recognized as an important research hotspot in this field. Several topics including exosomes, autophagy, biomarkers, osteogenic differentiation, microRNAs, steroid-induced osteonecrosis, mesenchymal stem cells, double-blind, early-stage osteonecrosis, and asymptomatic osteonecrosis were considered as research focuses in the near future.

Conclusion

Over the past two decades, increasing attention has been paid to global ONFH-related research. Our bibliometric findings provide valuable information for researchers to understand the basic knowledge structure, identify the current research hotspots, potential collaborators, and future research frontiers in this field.

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

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

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.

Development and validation of a prediction model for glucocorticoid-associated osteonecrosis of the femoral head by targeted sequencing

OBJECTIVE

To develop and validate a prediction model based on targeted sequencing for glucocorticoid (GC)-associated osteonecrosis of the femoral head (GA-ONFH) in GC-treated adults.

METHODS

This two-centre retrospective study was conducted between July 2015 and April 2019 at Zhongshan Hospital (training set) and the Sixth People's Hospital (test set) in Shanghai, China. All patients had a history of GC therapy, with a dose exceeding 2000 mg equivalent prednisone within 6 weeks. Patients were divided into two groups according to whether they were diagnosed with GA-ONFH within 2 years after GC initiation. Blood or saliva samples were collected for targeted sequencing of 358 single nucleotide polymorphisms and genetic risk score (GRS) calculating for developing GA-ONFH prediction model. Receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA) were performed to evaluate and validate the model.

RESULTS

. The training set comprised 117 patients, while the test set comprised 30 patients for external validation. Logistic regression analysis showed that GRS was significantly associated with GA-ONFH (OR 1.87, 95% CI: 1.48, 2.37). The ROC and DCA curves showed that the multivariate model considering GRS, age at GC initial, sex and underlying diseases had a discrimination with area under the ROC curve (AUC) of 0.98 (95% CI: 0.96, 1.00). This model was further externally validated using the test set with an AUC of 0.91 (95% CI: 0.81, 1.00).

CONCLUSION

Our prediction model comprising GRS, age, sex and underlying diseases yields valid predictions of GA-ONFH incidence. It may facilitate effective screening and prevention strategies of GA-ONFH.

The effect of a rehabilitation program after mesenchymal stromal cell transplantation for advanced osteonecrosis of the femoral head: a 10-year follow-up study

Objective

To assess the status of 10 patients with advanced osteonecrosis of the femoral head who underwent mesenchymal stromal cell transplants and a 12-week rehabilitation program 10 years earlier.

Design

Retrospective study.

Setting

University clinical research laboratory.

Participants

Patients (N=10) who had undergone mesenchymal stromal cell transplantation and rehabilitation for a single hip osteonecrosis of the femoral head 10 years prior to the current study were recruited by telephone. The average age was 31.7 years and all participants were men; radiographic stages were 3A in 6 patients and 3B in 4 patients before treatment.

Intervention

A 12-week rehabilitation program with follow-up once every 1 to 2 years was performed after mesenchymal stromal cell transplantation.

Main Outcome Measures

Radiographic analysis, clinical score, timed Up and Go test, hip function (range of motion, muscle strength), and Short Form-36 scores were assessed before treatment and 1 and 10 years after treatment.

Results

Upon imaging, 5 hips were found to be stable (stable group) and 5 had progressed (progressed group); 2 of the latter group required a total hip arthroplasty. The pretreatment radiographic stage of the progressed group was more advanced than that of the stable group. Body mass index was higher in the progressed group than in the stable group. Hip function and clinical score at 1 and 10 years after treatment improved in the hips of 8 patients without total hip arthroplasty. There were no severe adverse events during the rehabilitation.

Conclusions

The 12-week rehabilitation program and annual follow-up after mesenchymal stromal cell transplantation for osteonecrosis of the femoral head was associated with pain reduction, maintaining hip muscle strength, widening range of motion, and improving quality of life. The level and timing of weight-bearing and social activity should be planned according to the individual's lifestyle and body composition.

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

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

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

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

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

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

Collapse Progression or Cessation Affects the Natural History of Contralateral Osteonecrosis of the Femoral Head

BACKGROUND

It is unclear how the condition of one side of the hip joint affects the natural history of contralateral osteonecrosis of the femoral head (ONFH). This study aimed to investigate the natural progression of bilateral ONFH on the asymptomatic side between patients with collapse progression and cessation on the symptomatic side.

METHODS

The study included 109 patients with bilateral ONFH at the first visit, who were divided into two groups in accordance with the symptomatic side based on the collapse progression of ≥3 mm (progressive group: 74 hips) and collapse cessation of <3 mm (stable group: 35 hips) with a minimum follow-up of 3 years. The assessment parameters included age, gender, body mass index, etiology, type classification, and survival rates of the asymptomatic side with radiographic failure as the endpoints.

RESULTS

Age, gender, body mass index, and etiology were not different between the two groups; however, a difference was observed in the type classification of the symptomatic side. The 4-year survival rates were significantly different between the progressive (34.3%) and stable groups (85.7%). Multivariate Cox regression analysis showed that age <40 years (vs ≥40 years; hazard ratio [HR], 2.439), type C2 (vs B + C1; HR, 2.865), and collapse progression on the symptomatic side (vs collapse cessation; HR, 7.751) were independent factors determining collapse on the asymptomatic side.

CONCLUSION

Collapse progression on the symptomatic side is a poor prognostic factor for the natural history of contralateral ONFH.

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

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

Hip decompression combined with bone marrow concentrate and platelet-rich plasma for corticosteroid-induced osteonecrosis of the femoral head : mid-term update from a prospective study

Aims

Bone marrow-derived mesenchymal stem cells obtained from bone marrow aspirate concentrate (BMAC) with platelet-rich plasma (PRP), has been used as an adjuvant to hip decompression. Early results have shown promise for hip preservation in patients with osteonecrosis (ON) of the femoral head. The purpose of the current study is to examine the mid-term outcome of this treatment in patients with precollapse corticosteroid-induced ON of the femoral head.

Methods

In all, 22 patients (35 hips; 11 males and 11 females) with precollapse corticosteroid-induced ON of the femoral head underwent hip decompression combined with BMAC and PRP. Mean age and BMI were 43 years (SD 12) and 31 kg/m² (SD 6), respectively, at the time of surgery. Survivorship free from femoral head collapse and total hip arthroplasty (THA) and risk factors for progression were evaluated at minimum five-years of clinical follow-up with a mean follow-up of seven years (5 to 8).

Results

Survivorship free from femoral head collapse and THA for any reason was 84% and 67% at seven years postoperatively, respectively. Risk factors for conversion to THA included a high preoperative modified Kerboul angle (grade 3 or 4) based on preoperative MRI (hazard ratio (HR) 3.96; p = 0.047) and corticosteroid use at the time of decompression (HR 4.15; p = 0.039). The seven-year survivorship for patients with grade 1 or 2 Kerboul angles for conversion to THA for articular collapse, and THA for any reason, were 96% and 72%, respectively, versus THA for articular collapse and THA for any reason in patients with grade 3 or 4 Kerboul angles of 40% (p = 0.003) and 40% (p = 0.032).

Conclusion

At seven years, hip decompression augmented with BMAC and PRP provided a 67% survivorship free from THA in patients with corticosteroid-induced ON. Ideal candidates for this procedure are patients with low preoperative Kerboul angles and can stop corticosteroid treatment prior to decompression.

Cite this article: Bone Jt Open 2021;2(11):926–931.

Safety of Intra-articular Hip Corticosteroid Injections: A Matched-Pair Cohort Study

Background

Recent studies have suggested there is an increased risk of avascular necrosis (AVN), subchondral insufficiency fracture (SIF), femoral head collapse, and osteoarthritis (OA) progression in the 12-month period after hip corticosteroid/anesthetic injection (CSI); however, these studies have failed to account for preinjection OA severity or preexisting AVN/SIF.

Purpose

To compare these complication rates in patients treated with versus without hip CSI, while minimizing the aforementioned forms of selection bias present in previous investigations.

Study Design

Cohort study; Level of evidence, 3.

Methods

For all patients who had undergone a single hip CSI and hip magnetic resonance imaging (MRI) within the preceding 12 months at a single institution (CSI cohort), 2 musculoskeletal radiologists retrospectively graded OA severity (modified Kellgren-Lawrence classification) and femoral head collapse on hip radiographs taken within 12 months before, and 1 to 12 months after, CSI. Using identical methodology, radiographs from a control cohort (composed of hips that had never undergone CSI and had undergone hip MRI with hip radiographs taken within 12 months before, and 1-12 months after, MRI) were also graded. The cohorts were matched for age, sex, body mass index, and OA severity. Readers were blinded to cohort and time point. OA progression was defined as an increase in modified Kellgren-Lawrence grade ≥1 between radiographs.

Results

Included were 141 matched pairs. After exclusion of 48 matched pairs with at least 1 incidence of preexisting AVN or SIF on index MRI, CSI (n = 93; mean time between CSI and final hip radiograph, 5.43 months) and control (n = 93; mean time between MRI and final hip radiograph, 4.87 months), groups did not significantly differ in rates of OA progression (3.2% vs 3.2%) or new femoral head collapse (3.2% vs 2.2%).

Conclusion

In contrast to the findings of recent retrospective investigations, we did not find that patients treated with hip CSI had significantly higher rates of short-term OA progression or femoral head articular surface collapse after controlling for baseline OA severity and preexisting AVN or SIF. Future randomized trials investigating safety of hip CSI are needed to determine its exact short-term risk profile.