Fabricating patient-specific 3D printed drill guides to treat femoral head avascular necrosis.

BACKGROUND: Femoral head avascular necrosis (AVN), or death of femoral head tissue due to a lack of blood supply, is a leading cause of total hip replacement for non-geriatric patients. Core decompression (CD) is an effective treatment to re-establish blood flow for patients with AVN. Techniques aimed at improving its efficacy are an area of active research. We propose the use of 3D printed drill guides to accurately guide therapeutic devices for CD. METHODS: Using femur sawbones, image processing software, and 3D modeling software, we created a custom-built device with pre-determined drill trajectories and tested the feasibility of the 3D printed drill guides for CD. A fellowship trained orthopedic surgeon used the drill guide to position an 8 ga, 230 mm long decompression device in the three synthetic femurs. CT scans were taken of the sawbones with the drill guide and decompression device. CT scans were processed in the 3D modeling software. Descriptive statistics measuring the angular and needle-tip deviation were compared to the original virtually planned model. RESULTS: Compared to the original 3D model, the trials had a mean displacement of 1.440 ± 1.03 mm and a mean angle deviation of 1.093 ± 0.749º. CONCLUSIONS: The drill guides were demonstrated to accurately guide the decompression device along its predetermined drill trajectory. Accuracy was assessed by comparing values to literature-reported values and considered AVN lesion size. This study demonstrates the potential use of 3D printing technology to improve the efficacy of CD techniques.

Elucidating the role of the GC/GR/GLUT1 axis in steroid-induced osteonecrosis of the femoral head: A proteomic approach.

BACKGROUND: Steroid-induced osteonecrosis of the femoral head (SONFH) is a prevalent and incapacitating condition that affects the hip joint. Unfortunately, early diagnostic and treatment measures are limited. METHODS: Our study employed Tandem Mass Tag (TMT) labeling mass spectrometry (MS)-based quantitative proteome to compare the proteins of femoral head tissues in patients with SONFH with those of patients who sustained femoral neck fracture (FNF). We investigated the level and effects of glucose transporter member 1 (GLUT1) in SONFH patients and MC3T3-E1 cells and examined the function and molecular mechanism of GLUT1 in the context of SONFH using in vivo and in vitro approaches. RESULTS: The SONFH group exhibited significant changes in protein expression levels compared to the fracture group. Specifically, we observed the up-regulation of 86 proteins and the down-regulation of 138 proteins in the SONFH group. Among the differentially expressed proteins, GLUT1 was down-regulated and associated with glucose metabolic processes in the SONFH group. Further analysis using Parallel Reaction Monitoring (PRM), WB, and PCR confirmed that the protein was significantly down-regulated in both femoral head tissue samples from SONFH patients and dexamethasone-treated MC3T3-E1 cells. Moreover, overexpression of GLUT1 effectively reduced glucocorticoid (GC)-induced apoptosis and the suppression of osteoblast proliferation and osteogenic differentiation in MC3T3-E1 cells, as well as GC-induced femoral head destruction in GC-induced ONFH rat models. Additionally, our research demonstrated that GC down-regulated GLUT1 transcription via glucocorticoid receptors in MC3T3-E1 cells. CONCLUSIONS: GLUT1 was down-regulated in patients with SONFH; furthermore, down-regulated GLUT1 promoted apoptosis and inhibited osteoblast ossification in dexamethasone-induced MC3T3-E1 cells and contributed to GC-induced femoral head destruction in a SONFH rat model. Glucocorticoids inhibited the transcriptional activity of GLUT1, leading to a reduction in the amount and activity of GLUT1 in the cells and ultimately promoting apoptosis and inhibiting osteoblast ossification via the GC/GR/GLUT1 axis in SONFH.

Osteonecrosis risk after steroids-related treatment of COVID-19 is not negligible: A cross sectional study.

BACKGROUND & AIMS: During the pandemic, steroids use at various dosages and durations for the treatment of COVID-19 patients, especially in hospitalized patients, was a common and effective strategy. However, steroid administration is associated with osteonecrosis as an adverse event. The aim of the study was to examine the prevalence of skeleton osteonecrosis in COVID-19 patients treated with or without steroids. METHODS: Eighty randomly selected hospitalized COVID-19 patients were analyzed, of which 40 were managed with a published protocol including steroids and 40 did not receive steroids. Demographics and laboratory measurements including white blood cells count, C-reactive protein and ferritin were retrieved from the medical records. All patients underwent magnetic resonance imaging of the hips, shoulders, and knees. Subsequently, all patients were clinically examined and Oxford hip score (OHS) and EuroQol- 5 Dimension (EQ-5D-5 L) were documented. RESULTS: Three patients (3/40; 7.5 %) treated with steroids were diagnosed with femoral head osteonecrosis. None of the patients in the non-steroid-treated group developed osteonecrosis. There were no differences between the two groups regarding OHS and EQ-5D-5 L. Patients with osteonecrosis had higher ferritin levels, received higher doses of corticosteroids (median dose 2200 mg), and had longer hospitalization. CONCLUSIONS: COVID-19-related therapy with steroids resulted in lower prevalence of osteonecrosis than that previously recorded in patients with severe acute respiratory syndrome caused by coronavirus-type-1. However, this risk seems not negligible and therefore, high clinical suspicion for early diagnosis is warranted, given the fact that a great proportion of hospitalized patients received steroids during the COVID-19 pandemic.

Complex Bilateral Posterior Hip Dislocation with a Long-term Follow-up-A Case Report.

Bilateral hip dislocations are among the rarest traumatic incidents. We report a case of a 45-year-old, opium-addicted man with bilateral posterior hip dislocation and bilateral femoral head fractures proximal to the fovea with more comminution on the left side. After an unsuccessful closed reduction attempt, surgical reduction and internal fixation of the left and right femoral heads were performed on admission and 72 hours later. He was readmitted because of acute deep vein thrombosis (DVT) on the left side after six weeks and left femoral head avascular necrosis (AVN) after 14 months. All complications occurred on the left side regardless of the sooner intervention in this side compared with the right side. This may imply that the severity of the initial trauma could be a more important risk factor for AVN rather than other factors in case the reduction is delayed for more than six hours.

Fabricating Patient-Specific 3D Printed Drill Guides to Treat Femoral Head Avascular Necrosis.

Background: Femoral head avascular necrosis (AVN), or death of femoral head tissue due to a lack of blood supply, is a leading cause of total hip replacement for non-geriatric patients. Core decompression (CD) is an effective treatment to re-establish blood flow for patients with AVN. Techniques aimed at improving its efficacy are an area of active research. We propose the use of 3D printed drill guides to accurately guide therapeutic devices for CD. Methods: Using femur sawbones, image processing software, and 3D modeling software, we created a custom-built device with pre-determined drill trajectories and tested the feasibility of the 3D printed drill guides for CD. A fellowship trained orthopedic surgeon used the drill guide to position an 8 ga, 230 mm long decompression device in the three synthetic femurs. CT scans were taken of the sawbones with the drill guide and decompression device. CT scans were processed in the 3D modeling software. Descriptive statistics measuring the angular and needle-tip deviation were compared to the original virtually planned model. Results: Compared to the original 3D model, the trials had a mean displacement of 1.440±1.03 mm and a mean angle deviation of 1.093±0.749°. Conclusions: The drill guides were demonstrated to accurately guide the decompression device along its predetermined drill trajectory. Accuracy was assessed by comparing values to literature-reported values and considered AVN lesion size. This study demonstrates the potential use of 3D printing technology to improve the efficacy of CD techniques.

Animal Model Standardization for Studying Avascular Necrosis of the Femoral Head in Legg-Calvé-Perthes Disease.

Objective Testing an experimental model for ischemic necrosis of the femoral head in Legg-Calvé-Perthes disease by evaluating gait, imaging and morphohistology. Methods The operation was done in 11 piglets. Necrosis by cerclage in the right femoral neck was induced. Piglets were divided into group A, with 8 animals, euthanizing two in the 2 nd , 4 th , 6 th , and 8 th weeks, respectively; and group B, with 2 animals ( sham ), submitted to the surgical procedure without cerclage of the right femoral neck. The gait classification used was that of Etterlin. The frozen femurs were submitted to digital radiography and computed tomography. The height and width of the epiphysis and epiphysary coefficient were measured at study times. Light microscopy and immunohistochemistry with TGF-ß1 were performed. Results One animal died of sepsis in Group A. In this group, claudication was observed in all animals. On digital radiography and computed tomography, bone sclerosis, enlargement of the right femoral neck, flattening, collapse, and fragmentation of the right femoral head were observed. All epiphysis height and epiphysary coefficient values of the right femoral head were lower than the contralateral ones, in which were observed chondrocytes disordered and separated by gaps. A reduction in TGF-ß1 expression was observed at 2 and 6 weeks in the right femoral head and at eight in the left. In group B, there were no signs of necrosis and gait was normal. Conclusions The model presented reproduced macroscopic necrosis on digital radiography, computed tomography, and microscopy. Gait evaluation showed a good correlation with other ischemia findings. Level of Evidence V. Diagnostic studies.

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

INTRODUCTION: Femur head necrosis (FHN) is a challenging clinical disease with unclear underlying mechanism, which pathologically is associated with disordered metabolism. However, the disordered metabolism in cancellous bone of FHN was never analyzed by gas chromatography-mass spectrometry (GC-MS). OBJECTIVES: To elucidate altered metabolism pathways in FHN and identify putative biomarkers for the detection of FHN. METHODS: We recruited 26 patients with femur head necrosis and 22 patients with femur neck fracture in this study. Cancellous bone tissues from the femoral heads were collected after the surgery and were analyzed by GC-MS based untargeted metabolomics approach. The resulting data were analyzed via uni- and multivariate statistical approaches. The changed metabolites were used for the pathway analysis and potential biomarker identification. RESULTS: Thirty-seven metabolites distinctly changed in FHN group were identified. Among them, 32 metabolites were upregulated and 5 were downregulated in FHN. The pathway analysis showed that linoleic acid metabolism were the most relevant to FHN pathology. On the basis of metabolites network, L-lysine, L-glutamine and L-serine were deemed as the junctions of the whole metabolites. Finally, 9,12-octadecadienoic acid, inosine, L-proline and octadecanoic acid were considered as the potential biomarkers of FHN. CONCLUSION: This study provides a new insight into the pathogenesis of FHN and confirms linoleic acid metabolism as the core.

Updating Osteonecrosis of the Femoral Head.

Osteonecrosis of the femoral head (ONFH), a condition characterized by the presence of a necrotic bone lesion in the femoral head, is caused by a disruption in the blood supply. Its occurrence is more common in young and middle-aged adults and it is the main reason for performance of total hip arthroplasty in this age group. Its incidence is increasing along with increased use of glucocorticoids for management of adjuvant therapy for treatment of leukemia as well as organ transplantation and other myelogenous diseases. Current information on etiology and pathogenesis, as well as natural history, stage system, and treatments is provided in this review. A description of the Association Research Circulation Osseous (ARCO) criteria for classification of glucocorticoids- and alcohol-associated ONFH, 2019 ARCO staging system, and 2021 ARCO classification using computed tomography for the early stages of ONFH is also provided.

Animal Model Standardization for Studying Avascular Necrosis of the Femoral Head in Legg-Calvé-Perthes Disease / Padronização de modelo animal para o estudo da necrose isquêmica da cabeça femoral na doença de Legg-Calvé-Perthes

Abstract Objective Testing an experimental model for ischemic necrosis of the femoral head in Legg-Calvé-Perthes disease by evaluating gait, imaging and morphohistology. Methods The operation was done in 11 piglets. Necrosis by cerclage in the right femoral neck was induced. Piglets were divided into group A, with 8 animals, euthanizing two in the 2nd, 4th, 6th, and 8th weeks, respectively; and group B, with 2 animals (sham), submitted to the surgical procedure without cerclage of the right femoral neck. The gait classification used was that of Etterlin. The frozen femurs were submitted to digital radiography and computed tomography. The height and width of the epiphysis and epiphysary coefficient were measured at study times. Light microscopy and immunohistochemistry with TGF-β1 were performed. Results One animal died of sepsis in Group A. In this group, claudication was observed in all animals. On digital radiography and computed tomography, bone sclerosis, enlargement of the right femoral neck, flattening, collapse, and fragmentation of the right femoral head were observed. All epiphysis height and epiphysary coefficient values of the right femoral head were lower than the contralateral ones, in which were observed chondrocytes disordered and separated by gaps. A reduction in TGF-β1 expression was observed at 2 and 6 weeks in the right femoral head and at eight in the left. In group B, there were no signs of necrosis and gait was normal. Conclusions The model presented reproduced macroscopic necrosis on digital radiography, computed tomography, and microscopy. Gait evaluation showed a good correlation with other ischemia findings. Level of EvidenceV. Diagnostic studies.

Resumo Objetivo Testar um modelo experimental para necrose isquêmica da cabeça femoral na doença de Legg-Calvé-Perthes avaliando a marcha, exames de imagens e morfohistologia. Métodos Operaram-se 11 leitões. Induziu-se a necrose por cerclagem no colo femoral direito. Dividiram-se os leitões em grupo A com 8 animais, sacrificando-se dois na 2ª, 4ª, 6ª e 8ª semanas, respectivamente; e grupo B, com 2 animais (sham), submetidos ao procedimento cirúrgico sem a cerclagem do colo femoral direito. A classificação da marcha utilizada foi a de Etterlin. Os fêmures congelados foram submetidos à radiografia digital e tomografia computadorizada. Mediram-se a altura e largura da epífise e o coeficiente epifisário nos tempos de estudo. Realizou-se, microscopia de luz e imunohistoquímica com TGF-β1. Resultados Um animal morreu por sepse no grupo A. Neste grupo, observou-se claudicação em todos os animais. Na radiografia digital e tomografia computadorizada observaram-se: esclerose óssea, alargamento do colo femoral direito, achatamento, colapso e fragmentação da cabeça femoral direita. Todos os valores da altura da epífise e coeficiente epifisário da cabeça femoral direita foram menores que os contralaterais, nos quais observaram-se condrócitos desordenados e separados por lacunas. Observou-se redução da expressão do TGF-β1 com 2 e 6 semanas nas cabeças femorais direitas e nas esquerdas com oito. No grupo B, não ocorreram sinais de necrose e a marcha foi normal. Conclusões O modelo apresentado reproduziu a necrose macroscopicamente, na radiografia digital, tomografia computadorizada e microscopia. A avaliação da marcha demonstrou boa correlação com os demais achados de isquemia. Nível de EvidênciaV. Estudos diagnósticos.

Biomechanical Gait Analysis in Patients with Osteonecrosis of the Femoral Head.

Objectives Although osteonecrosis of the femoral head is a prevalent condition, its effects on gait parameters have not been thoroughly studied and are not well-established in the current literature. The primary aim of the present study is to describe gait in patients with a diagnosis of osteonecrosis. Methods This is a cross-sectional study. Nine patients diagnosed with osteonecrosis of the femoral head who were regularly followed-up at an outpatient clinic were selected for the present study and underwent gait analysis using Vicon Motion Capture Systems. Spatiotemporal data was obtained, and joint angles were calculated using an Euler angle coordinate system. Distal coordinate systems were used to calculate joint moments and force plates to obtain ground reaction forces. Results Patients with osteonecrosis presented with slower velocity (0.54 m/s ± 0.19) and smaller cadence (83.01 steps/min ± 13.23) than healthy patients. The pelvic obliquity range of motion was of 10.12° ± 3.03 and rotation was of 18.23° ± 9.17. The mean hip flexion was of 9.48° ± 3.40. Ground reaction forces showed reduced braking and propelling forces. Joint moments were reduced for flexion and adduction (0.42 Nm/kg ± 0.2 and 0.30 Nm/kg ± 0.11, respectively) but the abduction moment was increased (0.42 Nm/kg ± 0.18). Conclusions The present study showed that osteonecrosis of the femoral head presents compensatory gait mechanisms, with increased pelvic motion and decreased knee flexion to protect the hip joint. Decreased moments for hip flexion and adduction were also identified and muscle weakness for those groups may be correlated to the disease.

Epidemiological Characteristics and Trends of Primary Hip Arthroplasty in Five Tertiary Hospitals: A Multicenter Retrospective Study.

OBJECTIVE: The number of primary hip arthroplasty (PHA) has increased sharply in recent years. Whether the epidemiological characteristics and trends of PHA have changed are unknown. This study aims to analyze the epidemiological characteristics and trends of those patients are urgent for public health institutions. METHODS: The data of patients who underwent PHA in five tertiary hospitals from January 2011 to December 2020 were retrospectively reviewed. A total of 21,898 patients were included, most of whom were aged 60-69 years (25.1% males and 31.5% females). According to the hospitalization date, the patients were divided into two groups (Group A and Group B). The patients admitted between January 2011 and December 2015 were designated as Group A (7862), and those admitted between January 2016 and December 2020 were designated as Group B (14036). The patient data of the two groups, including sex, age, disease causes, body mass index (BMI), comorbidities, surgical procedures, hospital stay duration, and hospitalization costs, were analyzed by Pearson chi-Square test, Student t test or Mann-Whitney U test. RESULTS: More women were included in Group B than in Group A (58.5% vs 52.5%, P < 0.001). The mean age of Group B was less than that of Group A (62.27 ± 14.77 vs 60.69 ± 14.44 years, P < 0.001). Femoral head necrosis was the primary pathogenic factor in both groups, with a higher proportion in Group B than in Group A (55.5% vs 45.5%, P < 0.001). Significant differences were found between the two groups in BMI, comorbidities, surgical procedures, hospital stay duration, and hospitalization costs. Total hip arthroplasty (THA) was the most common surgical procedure in both groups, with a higher proportion in Group B than in Group A (89.8% vs 79.3%, P < 0.001). The proportion of patients with one or more comorbidities was significantly higher in Group B than in Group A (69.2% vs 59.9%, P < 0.001). In addition, Group B had a shorter hospital stay duration and higher hospitalization costs than Group A. CONCLUSION: Femoral head necrosis was the primary etiology for PHA in this study, followed by femoral neck fracture and hip osteoarthritis. Patients who underwent PHA exhibited a higher percentage of femoral head necrosis; underwent THA more often; and had larger BMIs, more comorbidities, higher medical costs, and younger age in the past decade.

Bone Metabolite Profile Differs between Normal and Femur Head Necrosis (FHN/BCO)-Affected Broilers: Implications for Dysregulated Metabolic Cascades in FHN Pathophysiology.

Femur head necrosis (FHN), also known as bacterial chondronecrosis with osteomyelitis (BCO), has remained an animal welfare and production concern for modern broilers regardless of efforts to select against it in primary breeder flocks. Characterized by the bacterial infection of weak bone, FHN has been found in birds without clinical lameness and remains only detectable via necropsy. This presents an opportunity to utilize untargeted metabolomics to elucidate potential non-invasive biomarkers and key causative pathways involved in FHN pathology. The current study used ultra-performance liquid chromatography coupled with high-resolution mass spectrometry (UPLC-HRMS) and identified a total of 152 metabolites. Mean intensity differences at p < 0.05 were found in 44 metabolites, with 3 significantly down-regulated and 41 up-regulated in FHN-affected bone. Multivariate analysis and a partial least squares discriminant analysis (PLS-DA) scores plot showed the distinct clustering of metabolite profiles from FHN-affected vs. normal bone. Biologically related molecular networks were predicted using an ingenuity pathway analysis (IPA) knowledge base. Using a fold-change cut off of -1.5 and 1.5, top canonical pathways, networks, diseases, molecular functions, and upstream regulators were generated using the 44 differentially abundant metabolites. The results showed the metabolites NAD+, NADP+, and NADH to be downregulated, while 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR) and histamine were significantly increased in FHN. Ascorbate recycling and purine nucleotides degradation were the top canonical pathways, indicating the potential dysregulation of redox homeostasis and osteogenesis. Lipid metabolism and cellular growth and proliferation were some of the top molecular functions predicted based on the metabolite profile in FHN-affected bone. Network analysis showed significant overlap across metabolites and predicted upstream and downstream complexes, including AMP-activated protein kinase (AMPK), insulin, collagen type IV, mitochondrial complex, c-Jun N-terminal kinase (Jnk), extracellular signal-regulated kinase (ERK), and 3ß-hydroxysteroid dehydrogenase (3ß HSD). The qPCR analysis of relevant factors showed a significant decrease in AMPKα2 mRNA expression in FHN-affected bone, supporting the predicted downregulation found in the IPA network analysis. Taken as a whole, these results demonstrate a shift in energy production, bone homeostasis, and bone cell differentiation that is distinct in FHN-affected bone, with implications for how metabolites drive the pathology of FHN.

Biomechanical Gait Analysis in Patients with Osteonecrosis of the Femoral Head / Análise biomecánica da marcha de pacientes com osteonecrose da cabeça do fémur

Abstract Objectives Although osteonecrosis of the femoral head is a prevalent condition, its effects on gait parameters have not been thoroughly studied and are not well-established in the current literature. The primary aim of the present study is to describe gait in patients with a diagnosis of osteonecrosis. Methods This is a cross-sectional study. Nine patients diagnosed with osteonecrosis of the femoral head who were regularly followed-up at an outpatient clinic were selected for the present study and underwent gait analysis using Vicon Motion Capture Systems. Spatiotemporal data was obtained, and joint angles were calculated using an Euler angle coordinate system. Distal coordinate systems were used to calculate joint momentsand forceplatestoobtaingroundreactionforces. Results Patients with osteonecrosis presented with slower velocity (0.54 m/s ± 0.19) and smaller cadence (83.01 steps/min ± 13.23) than healthy patients. The pelvic obliquity range of motion was of 10.12° ± 3.03 and rotation was of 18.23° ± 9.17. The mean hip flexion was of 9.48° ± 3.40. Ground reaction forces showed reduced braking and propelling forces. Joint moments were reduced for flexion and adduction (0.42 Nm/kg ± 0.2 and 0.30 Nm/kg ± 0.11, respectively) but the abduction moment was increased (0.42 Nm/kg ± 0.18). Conclusions The present study showed that osteonecrosis of the femoral head presents compensatory gait mechanisms, with increased pelvic motion and decreased knee flexion to protect the hip joint. Decreased moments for hip flexion and adduction were also identified and muscle weakness for those groups may be correlated to the disease.

Resumo Objetivos Embora a osteonecrose da cabeça do fêmur seja uma lesão prevalente, seus efeitos sobre os parâmetros da marcha não foram minuciosamente estudados e não estão bem estabelecidos na literatura atual. O objetivo principal do presente estudo é descrever a marcha em pacientes com osteonecrose. Métodos Trata-se de um estudo transversal. Nove pacientes com diagnóstico de osteonecrose da cabeça do fêmur, sob acompanhamento regular em ambulatório, foram selecionados para o presente estudo e submetidos à análise da marcha com Vicon Motion Capture Systems. Os dados espaciais e temporais foram obtidos e os ângulos articulares foram calculados com o sistema de coordenadas angulares de Euler. Sistemas de coordenadas distais e plataformas de força foram utilizados para o cálculo de momentos articulares e de forças de reação ao solo, respectivamente. Resultados Os pacientes com osteonecrose apresentaram menor velocidade (0,54 m/s ± 0,19) e menor cadência (83,01 passos/minuto ± 13,23) do que pacientes saudáveis. As amplitudes de movimento de obliquidade e rotação pélvica foram de 10,12°± 3,03 e 18,23° ± 9,17, respectivamente. A média de flexão do quadril foi de 9,48° ± 3,40. O estudo das forças de reação ao solo revelou redução das forças de frenagem e propulsão. Os momentos articulares de flexão e adução caíram (0,42 Nm/kg ± 0,2 e 0,30 Nm/kg ± 0,11), mas o momento de abdução aumentou (0,42 Nm/kg ± 0,18). Conclusões O presente estudo mostrou que a osteonecrose da cabeça do fêmur é associada a mecanismos compensatórios da marcha, com aumento da movimentação pélvica e diminuição da flexão do joelho para proteção da articulação do quadril. A redução dos momentos de flexão e adução do quadril também foi identificada e a fraqueza destes grupos musculares pode estar correlacionada à doença.

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.

Early efficacy of rotational femoral neck osteotomy with preservation of the round ligament in treating subchondral insufficiency fracture of the femoral head in young and middle-aged population / 中华创伤杂志

Objective:To investigate the short-term efficacy of rotational femoral neck osteotomy with preservation of the round ligament in the treatment of subchondral insufficiency fracture of the femoral head (SIFFH) in young and middle-aged people.Methods:A retrospective case series study was used to analyze the clinical data of 13 patients with SIFFH, who were admitted to 920th Hospital of Joint Logistics Support Force from January 2017 to January 2022. The patients included 10 males and 3 females, aged 22-49 years [(33.5±8.3)years]. There were 6 patients with fracture on the left hip and 7 on the right hip. All the patients were treated by rotational femoral neck osteotomy with preservation of the round ligament. Postoperatively, standardized joint functional training was given. The operative time and intraoperative bleeding were recorded. The modified Harris hip score and visual analogue score (VAS) were compared preoperatively, at 3, 6 months postoperatively and at the final follow-up. Radiological examinations were used to observe the occurrence of any collapse of the femoral head, non-union at osteotomy site or other complications.Results:The patients were followed up for 13-24 months [(17.9±3.1)months]. The operative time was (127.3±9.8)minutes, with the intraoperative bleeding of (393.9±21.9)ml. The values of modified Harris hip score were (61.6±3.3)points, (80.2±4.4)points, and (91.9±4.1)points at 3, 6 months postoperatively and at the final follow-up, respectively, being significantly higher than the preoperative (51.4±3.5)points (all P<0.05), and there were significant differences between different postoperative timepoints (all P<0.05). The values of VAS were (4.9±1.1)points, (3.0±0.9)points, and (1.4±0.5)points at 3, 6 months postoperatively and at the final follow-up, respectively, being significantly lower than preoperative (6.7±0.9)points (all P<0.05), and there were significant differences between different postoperative timepoints (all P<0.05). Imaging examination showed no femoral head collapse, with all the bones healed at the osteotomy site. There were no serious complications such as bone non-union, incision infection or peripheral nerve injury. Conclusion:Rotational femoral neck osteotomy with preservation of the round ligament in treating SIFFH in the young and middle-aged population has the advantages of shortened operative time, less intraoperative bleeding, promoted hip function recovery, attenuated pain and decreased complications, showing a satisfactory early effect.

Research progress in hip-preserving modalities for early osteonecrosis of the femoral head in young and middle-aged patients / 中华创伤杂志

Osteonecrosis of the femoral head (ONFH) is one of the common and difficult-to-treat orthopedic diseases caused by a variety of factors that lead to abnormal blood flow to the femoral head, which in turn leads to deformation and collapse of the femoral head and eventually results in severe hip joint dysfunction. The key to the treatment is early diagnosis and correct treatment according to the stage classification and active prevention of further aggravation of ONFH aiming to delay or avoid hip replacement surgery in young and middle-aged patients. At present, there are various non-surgical and surgical hip-preserving modalities for early ONFH, designed to slow down the progression of the disease, prevent the femoral head from collapsing and stop the mild collapse. In recent years, with the emergence and development of bone reconstruction biomaterials, artificial bone reconstruction after scraping of ONFH lesions has shown great potential in the treatment of early ONFH. The authors review the research progress in hip-preserving modalities for early ONFH in young and middle-aged patients from non-surgical and surgical perspectives, hoping to provide a reference for clinical treatment of early ONFH.

A deep transfer learning method using plain radiographs for the differential diagnosis of osteonecrosis of the femoral head with other hip diseases / 中华骨科杂志

Objective:To develop a deep transfer learning method for the differential diagnosis of osteonecrosis of the femoral head (ONFH) with other common hip diseases using anteroposterior hip radiographs.Methods:Patients suffering from ONFH, DDH, and other hip diseases including primary hip osteoarthritis, non-infectious inflammatory hip disease, and femoral neck fracture treated in the First Affiliated Hospital of Guangzhou University of Chinese Medicine from January 2018 to December 2020 were enrolled in the study. A clinical data set containing anteroposterior hip radiographs of the eligible patients was created. Data augmentation by rotating and flipping images was performed to enlarge the data set, then the data set was divided equally into a training data set and a testing data set. The ResNet-152, a deep neural network model, was used in the study, but the original Batch Normalization was replaced with Transferable Normalization to construct a novel deep transfer learning model. The model was trained to distinguish ONFH and DDH from other common hip diseases using anteroposterior hip radiographs on the training data set and its classification performance was evaluated on the testing data set.Results:The clinical data set was comprised of anteroposterior hip radiographs of 1024 hips, including 542 with ONFH, 296 with DDH, and 186 with other common hip diseases (56 hips with primary osteoarthritis, 85 hips with non-infectious inflammatory osteoarthritis, 45 hips with femoral neck fracture). After data augmentation, the size of the data set multiplied to 6144. The model was trained 100 050 times in each task. Accuracy was used as the representative parameter to evaluate the performance of the model. In the binary classification task to identify ONFH, the best accuracy was 95.80%. As for the multi-classification task for classification of ONFH and DDH from other hip diseases, the best accuracy was 91.40%. The plateau of the model was observed in each task after 50 000 times of training. The mean accuracy in plateaus was 95.35% (95% CI: 95.33%, 95.37%), and 90.85% (95% CI: 90.82%, 90.87%), respectively. Conclusion:The present study proves the encouraging performance of a deep transfer learning method for the first-visit classification of ONFH, DDH, and other hip diseases using the convenient and economical anteroposterior hip radiographs.

Traditional Chinese Medicine Regulates Wnt/β-catenin Signaling Pathway to Treat Steroid-induced Femoral Head Necrosis： A Review / 中国实验方剂学杂志

Steroid-induced necrosis of the femoral head （SNOFH） is a common orthopedic disease，which is difficult to cure and has poor clinical prognosis. The number of SNOFH patients in China is still increasing year by year，which seriously threatens human health. Long-term non-standard or short-term extensive use of hormone （GC） is an important reason for the occurrence of this disease. At present，SNOFH is mostly treated by surgical methods such as hip replacement，which has limitations of great harm to patients and high cost. In recent years，with the continuous deepening and innovation of traditional Chinese medicine（TCM） research，the use of TCM to treat SNOFH has been widely used in clinical practice. The main TCM pathogenesis of SNOFH is kidney deficiency and blood stasis. Therefore，TCM monomer and compound compound of tonifying kidney and promoting blood circulation are used to treat SNOFH. And TCM has obvious therapeutic effect，small side effects，less cost and other advantages. Glycoprotein/beta chain protein secretion （Wnt/beta- catenin） signaling pathway as a classic signaling pathway is closely related to the bone，between its by promoting bone marrow mesenchymal stem cell update，enhance the activity of osteoblast and suppress the apoptosis，which adjust the metabolic balance of bone tissue，increase bone density，will play an important role in the process of bone formation. In recent years，the use of TCM monomers and compounds to regulate Wnt/β-catenin signaling pathway to accelerate bone marrow mesenchymal stem cells，promote their transformation into osteoblasts，and maintain bone metabolic balance mechanism to treat SNOFH has become a new research hotspot. This article reviews the research progress of TCM in the prevention and treatment of SNOFH by regulating Wnt/β-catenin signaling pathway，in order to provide reference for the application of TCM in the treatment of SNOFH.

Avascular necrosis predictive factors after closed reduction in patients with developmental dysplasia of the hip.

Background: Developmental dysplasia of the hip (DDH) is a common pediatric orthopedic condition. Closed reduction (CR) is the conservative treatment approach with high success rates for DDH. However, avascular necrosis (AVN) is a severe potential complication after this procedure. This study retrospectively assessed the potential risk factors for AVN occurrence after CR and Spica cast immobilization. Materials and Methods: In a retrospective observational study, 71 patients (89 hips) with DDH aged 6-24 months old undergoing CR were enrolled. All patients were followed up for 3 years, and their demographic data, initial Tönnis grade, pre-reduction procedures, abduction angle in the Spica cast, and the AVN presence (based on Bucholz and Ogden classification [3rd-4th class]) were documented. Results: Of 71 patients (89 hips) with a mean age of 12.5 ± 3.9 months, 13 patients (18 hips) developed AVN. The mean age of patients in the AVN and non-AVN groups was 14.3 ± 4.9 and 12.2 ± 3 months (P = 0.07); also, the mean abduction angle in patients with and without AVN was 51.86 ± 3.66 and 58.46 ± 3.91 (P < 0.001) in univariate analysis. The distribution of initial Tönnis grade, and previous conservative procedures, adductor tenotomies during the CR were comparable between the two groups (P > 0.05). We found age 12 months and 54° in abduction angle as the best cutoff values for differentiating AVN patients from non-AVN and the risk of experiencing AVN for patients older than 12 months was odds ratio (OR) =4.22 (P = 0.06) and patients with abduction angle greater than 54 was OR = 34.88 (P < 0.001). Conclusion: In this study, older age at the time of intervention and larger abduction angle in the hip Spica cast were two predictors of experiencing AVN in DDH patients after undergoing CR treatment approach. Performing CR at a younger age and keeping the abduction angle lower than 54° in the hip Spica cast could help to have the best possible prognosis. Level of Evidence: IV, retrospective, observational, cross-sectional study.