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

BACKGROUND Femoral head necrosis(FHN)can significantly affect patients'psychological well-being and functional outcomes.However,the long-term relationship between postoperative depression,anxiety,and functional recovery in patients with FHN remains unclear.AIM To investigate the dynamic changes in postoperative depression and anxiety and their relationship with functional recovery in patients with FHN for 3 years.METHODS Ninety-three patients with FHN who underwent surgical treatment in March 2020 to 2023 were enrolled in this longitudinal study.Depression and anxiety status were assessed using the hospital anxiety and depression scale(HADS)at baseline,6 months,1,2,and 3 years postoperatively.Functional recovery was evaluated using the Harris hip score(HHS).The dynamic changes in HADS and HHS were analyzed using repeated measures ANOVA;the relationship between depre-ssion/anxiety status and functional recovery was examined using Pearson’s correlation analysis.RESULTS The mean HADS-depression(HADS-D)and HADS-anxiety(HADS-A)scores significantly improved over time(P<0.001).The prevalence of depression and anxiety decreased from 36.6%and 41.9%at baseline to 10.8%and 12.9%,respectively,at 3 years postoperatively.The mean HHS increased sig-nificantly from 52.3±10.5 at baseline to 88.1±7.2 at 3 years postoperatively(P<0.001).Significant negative correl-ations were found between HADS-D/HADS-A scores and HHS at all time points(P<0.05).CONCLUSION The severity of depression and anxiety negatively correlated with functional recovery,highlighting the importance of psychological interventions in the management of patients with FHN.

Three-dimensional analysis of age and sex differences in femoral head asphericity in asymptomatic hips in the United States

BACKGROUND The sphericity of the femoral head is a metric used to evaluate hip pathologies and is associated with the development of osteoarthritis and femoral-acetabular impingement.AIM To analyze the three-dimensional asphericity of the femoral head of asymptomatic pediatric hips.We hypothesized that femoral head asphericity will vary significantly between male and female pediatric hips and increase with age in both sexes.METHODS Computed tomography scans were obtained on 158 children and adolescents from a single institution in the United States(8-18 years;50%male)without hip pain.Proximal femoral measurements including the femoral head diameter,femoral head volume,residual volume,asphericity index,and local diameter difference were used to evaluate femoral head sphericity.RESULTS In both sexes,the residual volume increased by age(P<0.05).Despite significantly smaller femoral head size in older ages(>13 years)in females,there were no sex-differences in residual volume and aspherity index.There were no age-related changes in mean diameter difference in both sexes(P=0.07)with no significant sex-differences across different age groups(P=0.06).In contrast,there were significant increases in local aspherity(maximum diameter difference)across whole surface of the femoral head and all quadrants except the inferior regions in males(P=0.03).There were no sex-differences in maximum diameter difference at any regions and age group(P>0.05).Increased alpha angle was only correlated to increased mean diameter difference across overall surface of the femoral head(P=0.024).CONCLUSION There is a substantial localized asphericity in asymptomatic hips which increases with age in.While 2D measured alpha angle can capture overall asphericity of the femoral head,it may not be sensitive enough to represent regional asphericity patterns.

Treatment of a femoral neck fracture combined with ipsilateral femoral head and intertrochanteric fractures: A case report

BACKGROUND This article presents a rare case of a complex hip fracture involving the ipsilateral femoral neck,trochanter,and femoral head,that was accompanied by hip dislocation.Currently,there is no established standard treatment method for this specific type of fracture.Therefore,it is crucial to comprehensively consider factors such as patient age,fracture type,and degree of displacement to achieve a successful outcome.CASE SUMMARY A 38-year-old man sustained a comminuted fracture of his right hip as a result of a car accident.The injuries included a fracture of the femoral head,a fracture of the femoral neck,an intertrochanteric fracture of the femur,and a posterior dislocation of the hip on the same side.We opted for a treatment approach combining the use of a proximal femoral locking plate,cannulated screws,and Kirschner wires.Following the surgery,we developed an individualized rehabil-itation program to restore patient limb function.CONCLUSION For this complex fracture,we selected appropriate internal fixation and for-mulated individualized rehabilitation,which ultimately achieved good results.

Surgical Treatment of Osteonecrosis of the Femoral Head Using Minimally Invasive Surgical Drilling and Cancellous Grafting at Brazzaville University Hospital

Introduction: Osteonecrosis of the femoral head (ONTF) is a debilitating condition. Several treatments have been proposed with controversial results. The aim of our study was to evaluate treatment by surgical drilling coupled with in situ cancellous grafting. Materials and methods: Our study was a case-control study conducted at Brazzaville University Hospital from 1st January 2018 to 31 December 2023. It compared two groups of patients with ONTF: non-operated (13 patients, 20 hips) and operated (22 patients, 35 hips). We used the visual digital scale (VDS) for pain assessment, the Merle D’Aubigne-Postel (MDP) scoring system for clinical and functional assessment, and the evolution of necrosis. Results: The group of non-operated patients had a mean age of 35.69 ± 3.4 years, no improvement in pain with an EVN above seven at the last recoil and a mean global MDP score falling from 12.7 before offloading to 10.13 at one year. The group of patients operated on had a mean age of 37.86 ± 7.02 years, a significant reduction in pain (p = 0.00004) and a significantly increased MDP score (p = 0.0034). A comparison of the two groups of patients showed significant stabilization of the necrotic lesions in the operated patients (p = 0.00067), with better satisfaction in the same group. Conclusion: Surgical drilling combined with grafting in the treatment of early-stage ONTF has improved progress in our series. The technique is reproducible and less invasive. It has made it possible to delay unfavorable progression and, consequently, hip replacement surgery.

Bilateral Avascular Necrosis of the Femoral Head in Renal Transplant Recipient: A Case Report

Osteoarticular complications are common after renal transplantation. The complications may result from the bone condition prior to transplantation or the iatrogenic effects of the treatments administered. These complications lead to significant morbidity and mortality, in addition to chronic pain and functional impairment. We report the clinical case of bilateral avascular necrosis (AVN) of the femoral head in a kidney transplant recipient. Clinical Case: 53-year-old male with a history of chronic hypertension. He underwent chronic hemodialysis for 12 months and was treated with Entecavir for chronic hepatitis B. The patient received a kidney transplant from a non-related living donor. Induction therapy included Thymoglobulin along with tapered corticosteroids, reaching a dose of 5 mg/day after 3 months, Mycophenolate mofetil (2 g/day), and Tacrolimus adjusted based on residual levels. There was good recovery of renal graft function. After six months, the patient reported bilateral hip pain and functional impairment of both lower limbs. Pelvic X-rays showed signs suggestive of bilateral AVN of the femoral heads. The diagnosis was confirmed by MRI. The patient underwent right hip drilling and total left hip replacement (THR). A right THR was performed a year later. Conclusion: AVN constitutes a frequent cause of morbidity and mortality after RT. The pathophysiology of osteonecrosis remains complex and multifactorial. We emphasize the importance of conducting a thorough assessment of bone health in patients both before and after RT.

Prosthetic modeling for femoral head based on ellipsoid fitting

A novel modeling method which can restore the shape of the femoral head with collapse induced by ischemic necrosis is proposed. First, sequential tomograms of the hip are obtained from a CT scan; secondly, an accurate and automatic method is used to extract the profile of the acetabulum; thirdly, a hybrid method is utilized to gather fiducial marks on the acetabulum; fourthly, bulky error sampling points are removed. Finally, an ellipsoid fitting method is used to fit the ellipsoid model of the femoral head. Two male sufferers with different necrosis extents are chosen as experimental subjects for contrastive simulation. Fifty cases of different ages （from 25 to 79 years old） are utilized for statistical comparisons of matching errors. The prosthetic models highly resemble the primary shape of the femoral head in health. This new method provides not only a theoretical model for accurate operation position fixing in an orthopaedics clinic, but it is also an innovative practical means for the individual manufacture of artificial femoral heads.

An Experimental Study of Pathogenesis of Steroid-induced Avascular Necrosis of Femoral Head

Objective: To explore the pathogenesis of avascular necrosis of femoral head(ANFH) and search an effective method for clinical practice. Methods: Twenty-four Japanese rabbitswere divided into 2 groups of models and controls. ANFH models were produced byintramuscular-injection of large dosage of steroid to rabbits for 8 weeks. From the 4th, 8th and12th week after production of models, 2 rabbits of each group were sacrificed to observe thestructure of femoral head through light microscope and scanning electron microscope. The contents ofNitric Oxide (NO), tissue-type plasminogen activator (t-PA) and -plasminogen activator inhibitor(PAI) in plasma of the 4 rabbits in each group were estimated at the same time. Results: Comparedwith control group, the rabbits of model group exhibited many differences: such as osteoporosis offemoral head, the presence of more bone lacuna and fat cell through light microscope observing; thebroken and sunk bone trabecula, the loosen and broken collagen fibers on the surface of bone matrixthrough scanning electron microscope observing. Compared with control group, the Concentration ofNO and t-PA in plasma of the model rabbits decreased obviously, but the Concentration of the PAIincreased obviously. Conclusion: The steroid-induced ANFH might be related to the lower level of NOand the descent of fibrinolytic activity.

A Rabbit Model of Hormone-induced Early Avascular Necrosis of the Femoral Head

Objective To establish an experimental model of early stage avascular necrosis of the femoral head （ANFH） caused by corticosteroid in adult rabbits and to observe the pathological changes with various imaging techniques. Methods ANFH was induced by a combination of hypersensitivity vasculitis caused by injection of horse serum and subsequent administration of a high dose of corticosteroid. The pathological changes were detected with digital radiography （DR）, computed tomography （CT）, magnetic resonance imaging （MRI）, ink artery infusion angiography, hematoxylin-eosin staining, and immunohistochemistry. Results The imageological and pathological changes corresponded to the clinical characteristics of early stage ANFH. DR showed bilaterally increased bone density, an unclear epiphyseal line, and blurred texture of cancellous bone. CT showed spot-like low-density imaging of cancellous bone, thinner cortical bone, osteoporosis, and an unclear epiphyseal line. MR! showed bone marrow edema and spot-like high signals in T2-weighted imaging in cancellous bone. Ink artery infusion angiography showed fewer obstructed blood vessels in the femoral head. HE staining of pathological sections showed fewer trabeculae and thin bone, an increased proportion of empty osteocyte lacunae, decreased hematopoiesis, thrombosis, and fat cell hypertrophy. Immunohistochemistry showed attenuated expression of vascular endothelial growth factor in osteoblasts and chondrocytes, and on the inner membrane of blood vessels. Conclusion Experimental rabbit model of early stage ANFH caused by corticosteroid can be successfully established and provide the foundation for developing effective methods to treat early stage ANFH.

Association of Toll-like receptor 4 Signaling Pathway with Steroid-induced Femoral Head Osteonecrosis in Rats

Osteonecrosis of the femoral head is frequently observed in patients treated with excessive corticosteroids. However, the pathogenesis of corticosteroid-induced osteonecrosis remains unclear. The purpose of this study was to investigate the role of Toil-like receptor 4 （TLR4） signaling pathway in steroid-induced femoral head osteonecrosis in rats. Male Sprague-Dawley rats were injected intramus- cularly with 20 mg/kg methylprednisolone （MP） for 8 weeks, twice per week. The animals were sacri- ficed at 2, 4 and 8 weeks after the last MP injection, respectively, and then allocated to the 2-, 4- and 8-week model groups （n=24 each）. Rats in the control group （n=12） were not given any treatment. Histopathological analysis was performed and the concentration of tartrate-resistant acid phosphatase （TRAP） in plasma was determined. The activation of osteoclasts in the femoral head was assessed by TRAP staining. The expression of TLR4, MyD88, TRAF6 and NF-Id3 p65 that are involved in TLR4 signaling, and MCP-1 production were detected by using real-time PCR （RT-PCR） and Western blotting. The results showed that the osteonecrosis in the femoral head was clearly observed and the concentra- tion of TRAP in the plasma was increased in the model rats. The femoral head tissues in MP-treated rats were positive for TRAP and the intensity of TRAP staining was greater in MP-treated rats than in con- trol rats. As compared with the control group, the mRNA expression of TLR4 signaling-related factors was enhanced significantly at 4 and 8 weeks, and the protein levels of these factors increased signifi- cantly with time. It was concluded that MP could induce the femoral head osteonecrosis in rats, which was associated with osteoclast activation via the TLR4 signaling pathway. These findings suggest that TLR4 signaling pathway plays a pivotal role in the pathogenesis of steroid-induced osteonecrosis.

Surface-based map plasticity of brain regions related to sensory motor and pain information processing after osteonecrosis of the femoral head

Pain is one of the manifestations of hip disorder and has been proven to lead to the remodeling of somatotopic map plasticity in the cortex.However,most studies are volume-based which may lead to inaccurate anatomical positioning of functional data.The methods that work on the cortical surface may be more sensitive than those using the full brain volume and thus be more suitable for map plasticity study.In this prospective cross-sectional study performed in Yueyang Hospital of Integrated Traditional Chinese and Western Medicine,Shanghai University of Traditional Chinese Medicine,China,20 patients with osteonecrosis of the femoral head(12 males and 8 females,aged 56.80±13.60 years)and 20 healthy controls(9 males and 11 females,aged 54.56±10.23 years)were included in this study.Data of resting-state functional magnetic resonance imaging were collected.The results revealed that compared with healthy controls,compared with the healthy controls,patients with osteonecrosis of the femoral head(ONFH)showed significantly increased surface-based regional homogeneity(Re Ho)in areas distributed mainly in the left dorsolateral prefrontal cortex,frontal eye field,right frontal eye field,and the premotor cortex and decreased surface-based Re Ho in the right primary motor cortex and primary sensory cortex.Regions showing significant differences in surfacebased Re Ho values between the healthy controls and patients with ONFH were defined as the regions of interests.Seed-based functional connectivity was performed to investigate interregional functional synchronization.When the areas with decreased surface-based Re Ho in the frontal eye field and right premotor cortex were used as the regions of interest,compared with the healthy controls,the patients with ONFH displayed increased functional connectivity in the right middle frontal cortex and right inferior parietal cortex and decreased functional connectivity in the right precentral cortex and right middle occipital cortex.Compared with healthy controls,patients with ONFH showed significantly decreased cortical thickness in the para-insular area,posterior insular area,anterior superior temporal area,frontal eye field and supplementary motor cortex and reduced volume of subcortical gray matter nuclei in the right nucleus accumbens.These findings suggest that hip disorder patients showed cortical plasticity changes,mainly in sensorimotor-and pain-related regions.This study was approved by the Medical Ethics Committee of Yueyang Hospital of Integrated Traditional Chinese and Western Medicine,Shanghai University of Traditional Chinese Medicine(approval No.2018-041)on August 1,2018.

Experimental Study of Vascular Endothelial Growth Factor Gene Therapy for Avascular Necrosis of the Femoral Head

To explore a new method for the therapy of the avascular necrosis of the femoral head, the recombinant plasmid pCD-hVEGF 165 was mixed with collagen and was implanted in the necrotic femoral head The expression of vascular endothelial growth factor (VEGF) was detected by RNA dot hybridization and immunohistochemical method The repair of the femoral head was observed by histological method The results showed that the expression of VEGF was detectable in the femoral head treated with VEGF gene Angiogenesis in these femoral heads was more abundant than the control Bone repairing was augmented in the femoral head treated with VEGF gene The results suggest that angiogenesis in bone tissue could be augmented by gene transfection of VEGF and bone repairing would be accelerated accordingly

Microstructures and properties of cancellous bone of avascular necrosis of femoral heads

The aim of this study is to investigate microscopic structure and characterize cancellous bone of avascular necrosis of the femoral head （ANFH）. The rabbit model of the ANFH is established. The histopathologic features are studied successfully. The differences between the steroidinjection group （S.G.） and the controlled group （C.G.） are examined, including the weight of rabbits, the hematological examination and the three-dimensional stnactures. It is found that the plasma levels of cholesterol （CHO）, high-density lipoprotein （HDL） and low-density lipoprotein （LDL） in S.G. are lower than those in C.G. when the triglyceride （TG） increased in the S.G.; but the bone mineral content （BMC） and the structural model index （SMI） of the organ and tissue decreased significantly in S.G. Three-dimensional structures of the femoral head are obtained using micro-computed tomography （CT） scanning and the mechanical model is established to analyze the influences of these structural changes on the mechanical properties of the cancellous bone.

Protective Effect of Human Umbilical Cord Mesenchymal Stem Cells in Glucocorticoid-induced Osteonecrosis of Femoral Head

Objective:To evaluate the effect of human umbilical cord mesenchymal stem cells(hUC-MSCs)on preventing rats from glucocorticoid-induced osteonecrosis of femoral head(GC-ONFH)in the early stage in vivo and to investigate the possible mechanism of hUC-MSCs in regulating the balance of osteogenesis and adipogenesis.Methods:All rats were randomly divided into 3 groups:control group(C group),model group(M group),and intervention group(Ⅰ group).The model of GC-ONFH was developed by a sequential administration of lipopolysaccharide and methylprednisolone.The rats in the Ⅰ group were treated with caudal vein injection of hUC-MSCs.Six weeks later,the blood samples were obtained to measure the activity of alkaline phosphatase(ALP)and the content of triglyceride(TG)in serum,and the femoral heads were harvested and observed by hematoxylin-eosin staining,Micro-CT,Western blot and real-time quantitative polymerase chain reaction.Results:After intervention of hUC-MSCs,the necrosis rate of femoral head decreased from 83%(10/12)to 33%(4/12),the rate of empty bone lacuna was significantly decreased,the activity of ALP increased significantly,the content of TG decreased significantly,the bone density increased obviously,the expression of RUNX2 and Col Ⅰ increased significantly and the expression of PPARγ decreased significantly.Conclusion:These results revealed that caudal vein injection of hUC-MSCs can effectively reduce the incidence of GC-ONFH in rats by increasing ALP activity and reducing TG content in serum,increasing bone mineral density,promoting the expression of RUNX2 and Col I,and inhibiting the expression of PPARγ.

Modified technique of advanced core decompression for treatment of femoral head osteonecrosis

BACKGROUND Osteonecrosis of the femoral head(ONFH)is a destructive condition most commonly affecting young and middle-aged patients.The leading consequence of ONFH is often a significant articular disability.Effective joint-preserving surgical treatments are urgently needed for patients with early stage ONFH when outcomes of treatment are in general better than the advanced stage disease.AIM To introduce a new surgery procedure called percutaneous expanded core decompression and mixed bone graft technique,which is a new way of jointpreserving surgical treatments.METHODS The clinical data of 6 patients with ONFH diagnosed and treated with the procedure called percutaneous expanded core decompression and mixed bone graft technique at The First Hospital of Qiqihar from March 2013 to August 2019 were retrospectively analyzed;the follow-up ended in December 2019.RESULTS There were 6 male patients with an average age of 43 years in our study.Gratifying results have been obtained from the comparison of Harris hip score,visual analogue scale,and imaging examination before and after operation.CONCLUSION This new modified technique is simple,safe,and reliable.No serious perioperative complications were observed in our cases.Advantages of the single blade expandable reamer are obvious.The adjuvant substance is inexpensive and easy to obtain.Thus,this technique is an effective joint-preserving surgical treatment for patients with early stage of ONFH.

Safety and efficacy of surgical hip dislocation in managing femoral head fractures: A systematic review and meta-analysis

BACKGROUND Femoral head fractures(FHFs)are considered relatively uncommon injuries;however,open reduction and internal fixation is preferred for most displaced fractures.Several surgical approaches had been utilized with controversial results;surgical hip dislocation(SHD)is among these approaches,with the reputation of being demanding and leading to higher complication rates.AIM To determine the efficacy and safety of SHD in managing FHFs by reviewing the results reported in the literature.METHODS Major databases including PubMed,Embase,Web of Science,and Cochrane Central Register of Controlled Trials were searched to identify studies reporting on outcomes of SHD utilized as an approach in treating FHFs.We extracted basic studies data,surgery-related data,functional outcomes,radiological outcomes,and postoperative complications.We calculated the mean differences for continuous data with 95%confidence intervals for each outcome and the odds ratio with 95%confidence intervals for binary outcomes.P<0.05 was considered significant.RESULTS Our search retrieved nine studies meeting our inclusion criteria,with a total of 129 FHFs.The results of our analysis revealed that the average operation time was 123.74 min,while the average blood loss was 491.89 mL.After an average followup of 38.4 mo,a satisfactory clinical outcome was achieved in 85%of patients,ranged from 30%to 86%,with avascular necrosis,heterotopic ossification,and osteoarthritis being the most common complications occurring at an incidence of 12%,25%,and 16%,respectively.Trochanteric flip osteotomy nonunion and trochanteric bursitis as a unique complication of SHD occurred at an incidence of 3.4%and 3.8%,respectively.CONCLUSION The integration of SHD approach for dealing with FHFs offered acceptable functional and radiological outcomes with a wide range of safety in regards to the hip joint vascularity and the development of avascular necrosis,the formation of heterotopic ossification,and the development of posttraumatic osteoarthritis;however,it still carries its unique risk of trochanteric flip osteotomy nonunion and persistent lateral thigh pain.

BASIC FIBROBLAST GROWTH FACTOR GENE TRANSFECTION TO ENHANCE THE REPAIR OF AVASCULAR NECROSIS OFTHE FEMORAL HEAD

Objective To explore a new method for the therapy of avascular necrosis of the femoral head. Method The recombinant plasmid pCD-rbFGF was mixed with collagen and was implanted in the necrotic femoral head. Expression of basic fibroblast growth factor (bFGF) was examined by RT-PCR and immunohistochemical method. Re-pair of the femoral head was observed by histological and histomorphometric analysis. Result Expression of bFGF was detected in the femoral head transfected with bFGF gene, indicating significant increase of angiogenesis 2 weeks after gene transfection and increased new bone formation 8 weeks after gene transfection on histom-orphometric analysis (P< 0.01). Conclusion Transfection of bFGF gene enhances bone tissue angiogenesis. Repair in osteonecrosis would be accelerated accordingly.

Effects of individual shock wave therapy vs celecoxib on hip pain caused by femoral head necrosis

BACKGROUND Celecoxib has been used to treat hip discomfort and functional difficulties associated with osteonecrosis of the femoral head(ONFH),although significant adverse reactions often follow long-term use.Extracorporeal shock wave therapy(ESWT)can delay the progression of ONFH,alleviate the pain and functional limitations it causes,and avoid the adverse effects of celecoxib.AIM To investigate the effects of individual ESWT,a treatment alternative to the use of celecoxib,in alleviating pain and dysfunction caused by ONFH.METHODS This was a randomized,controlled,double-blinded,non-inferiority trial.We examined 80 patients for eligibility in this study;8 patients were excluded based on inclusion and exclusion criteria.A total of 72 subjects with ONFH were randomly assigned to group A(n=36;celecoxib+alendronate+sham-placebo shock wave)or group B(n=36;individual focused shock wave[ESWT based on magnetic resonance imaging three-dimensional(MRI-3D)reconstruction]+alendronate).The outcomes were assessed at baseline,at the end of treatment,and at an 8-wk follow-up.The primary outcome measure was treatment efficiency after 2 wk of intervention using the Harris hip score(HHS)(improvement of 10 points or more from the baseline was deemed sufficient).Secondary outcome measures were post-treatment HHS,visual analog scale(VAS),and Western Ontario and McMaster Universities Osteoarthritis Index(WOMAC)scores.RESULTS After treatment,the pain treatment efficiency of group B was greater than that of group A(69%vs 51%;95%CI:4.56%to 40.56%),with non-inferiority thresholds of-4.56%and-10%,respectively.Furthermore,the HHS,WOMAC,and VAS scores in group B dramatically improved during the follow-up period as compared to those in group A(P<0.001).After therapy,the VAS and WOMAC in group A were significantly improved from the 2nd to 8th wk(P<0.001),although HHS was only significantly altered at the 2 wk point(P<0.001).On the 1st d and 2nd wk after treatment,HHS and VAS scores were different between groups,with the difference in HHS lasting until week 4.Neither group had severe complications such as skin ulcer infection or lower limb motorsensory disturbance.CONCLUSION Individual shock wave therapy(ESWT)based on MRI-3D reconstruction was not inferior to celecoxib in managing hip pain and restrictions associated with ONFH.

Previously unexplored etiology for femoral head necrosis:Metagenomics detects no pathogens in necrotic femoral head tissue

BACKGROUND Osteonecrosis of the femoral head(ONFH)is a frequent and refractory disease whose pathogenesis has not yet been elucidated.Infection and other factors that reduce the local blood supply can lead to bone necrosis.AIM To aim of this study was to assess the relationship of ONFH with bone infection by use of metagenomic sequencing.METHODS Twelve patients with idiopathic ONFH and 12 comparable controls who were undergoing hip arthroplasty were followed up in parallel.Necrotic femoral head specimens were collected for bacterial and fungal cultures using standard methods.Bone specimens were subjected to preliminary processing,and metagenomics sequencing of microorganisms was performed.A one-way analysis of variance was used to compare bacterial species in the two groups.RESULTS Bacterial and fungal cultures exhibited no evidence of microbial growth in all isolated necrotic femoral head tissues.We thus performed metagenomic sequencing and classified the species as suspected pathogens or suspected background microorganisms based on known bacterial pathogenicity.There was no evidence of viruses,fungi,parasites,M.tuberculosis complex,or mycoplasma/chlamydia.There were also no significant differences in suspected pathogens or suspected background microorganisms(P>0.05).CONCLUSION Although we found no pathogens specific for ONFH in necrotic femoral head tissue,our research provides a foundation for future research on the metagenomics of bone pathogens.

Tissue level microstructure and mechanical properties of the femoral head in the proximal femur of fracture patients

This study aims to investigate the regional variations of trabecular morphological parameters and mechanical parameters of the femoral head,as well as to determine the relationship between trabecular morphological and mechanical parameters.Seven femoral heads from patients with fractured proximal femur were scanned using a micro-CT system.Each femoral head was divided into 12 sub-regions according to the trabecular orientation.One 125 mm^3 trabecular cubic model was reconstructed from each sub-region.A total of 81 trabecular models were reconstructed,except three destroyed sub-regions from two femoral heads during the surgery.Trabecular morphological parameters,i.e.trabecular separation（Tb.Sp）,trabecular thickness（Tb.Th）,specific bone surface（BS/B V）,bone volume fraction（BV/TV）,structural model index（SMI）,and degree of anisotropy（DA） were measured.Micro-finite element analyses were performed for each cube to obtain the apparent Young＇s modulus and tissue level von Mises stress distribution under 1%compressive strain along three orthogonal directions,respectively.Results revealed significant regional variations in the morphological parameters（P〈0.05）.Young＇s moduli along the trabecular orientation were significantly higher than those along the other two directions.In general,trabecular mechanical properties in the medial region were lower than those in the lateral region.Trabecular mechanical parameters along the trabecular orientation were significantly correlated with BS/BV,BV/TV,Tb.Th,and DA.In this study,regional variations of microstructural features and mechanical properties in the femoral head of patients with proximal femur fracture were thoroughly investigated at the tissue level.The results of this study will help to elucidate the mechanism of femoral head fracture for reducing fracture risk and developing treatment strategies for the elderly.

The changes of nitric oxide and hemorheology in steroid-induced avas-cular necrosis of femoral head

Objective: To explore the pathogenesis of avascular necrosis of femoral head (ANFH), the early diagnosis index and the treatment effective index of ANFH in clinical practice. Methods: Twenty-four Japanese rabbits were divided into 2 groups: model group and control group. ANFH models were produced by intramuscular injection of large dosage of steroid to rabbits for 8 weeks. On the 4 th, 8 th week after the injection, two rabbits each time from each group were taken to observe the structure of femoral head by light microscope and scanning electron microscope. Four other stomach-empty rabbits from each group were also used to test the contents of Nitric Oxide (NO), contents of the hemorheology indexes. Results: Compared with the control group, the rabbits in the model group exhibited osteoporosis of femoral head and more bone lacuna and more fat cells through light microscope. Through scanning electron microscope observation bone trabecula were broken and sunk, and collagen fibers on the surface of bone matrix became loosen and broken, more osteocyte had pyknosis, adipocyte in the medullary cavity were enlarged and subchondral arterioles and capillaries of the femoral head were pressed by adipocyte. Compared with the control group, the model rabbits contained less NO and obvious increase of the plasma viscosity (PV), low blood viscosity (LBV), erythrocyte hematocrit (HCT), indices of erythrocyte rigidity (TK) and indices of erythrocyte aggregation (AI), plasma fibrin level (PFL) (P<0. 01) and an increase of erythrocyte electrophoresis rate (ERT) (P< 0.05). High blood viscosity (HBV), and erythrocyte sedimentation rate (ESR) were unchanged. Conclusion: The steroid-induced ANFH might be related to less NO and the abnormal hemorheology; and NO and hemorheology should be considered as an early diagnosis index for ANFH in clinical practice.