Exosomes derived from M2 macrophages prevent steroid-induced osteonecrosis of the femoral head by modulating inflammation, promoting bone formation and inhibiting bone resorption

Inflammatory reactions are involved in the development of steroid-induced osteonecrosis of the femoral head(ONFH). Studies have explored the therapeutic efficacy of inhibiting inflammatory reactions in steroid-induced ONFH and revealed that inhibiting inflammation may be a new strategy for preventing the development of steroid-induced ONFH. Exosomes derived from M2 macrophages(M2-Exos) display anti-inflammatory properties. This study aimed to examine the preventive effect of M2-Exos on early-stage steroid-induced ONFH and explore the underlying mechanisms involved. In vitro, we explored the effect of M2-Exos on the proliferation and osteogenic differentiation of bone marrow-derived mesenchymal stem cells(BMMSCs). In vivo, we investigated the role of M2-Exos on inflammation, osteoclastogenesis, osteogenesis and angiogenesis in an early-stage rat model of steroid-induced ONFH. We found that M2-Exos promoted the proliferation and osteogenic differentiation of BMMSCs. Additionally, M2-Exos effectively attenuated the osteonecrotic changes, inhibited the expression of proinflammatory mediators, promoted osteogenesis and angiogenesis, reduced osteoclastogenesis, and regulated the polarization of M1/M2 macrophages in steroid-induced ONFH. Taken together, our data suggest that M2-Exos are effective at preventing steroid-induced ONFH. These findings may be helpful for providing a potential strategy to prevent the development of steroid-induced ONFH.

Risk factor analysis of femoral avascular necrosis after operation for Tönnis grade IV developmental dysplasia of the hip

PURPOSE

We explored the risk factors for avascular necrosis (AVN) after surgery using open reduction, pelvic osteotomy, and femoral osteotomy for Tönnis grade IV developmental dysplasia of the hip (DDH).

METHODS

In this retrospective study, we collected data of patients with Tönnis grade IV DDH treated with open reduction and pelvic osteotomy combined with femoral osteotomy from January 2012 to May 2020. The patients were divided into the AVN group and non-AVN group using the Kalamchi-MacEwen classification system. The clinical and imaging data of the two groups were collected, and the possible risk factors were included in the analysis. Univariate and multivariate logistic regression analyses were used to identify the independent risk factors and odds ratios of AVN.

RESULTS

In all, 254 patients (mean age; 2.6±0.9 years, 278 hips) were included. The mean follow-up time was 3.8±1.5 years. A total of 89 hips (32%) were finally classified as AVN (Kalamchi-MacEwen II-IV). Univariate analysis showed significant associations with AVN for age (p=0.006), preoperative femoral neck anteversion (FAV) (p<0.001), femoral osteotomy length to dislocation height ratio (FDR) <1 (p<0.001), and the epiphyseal ossific nucleus diameter to the neck diameter ratio (ENR) <50% (p=0.009). Multivariate logistic regression analysis showed that only excessive preoperative FAV (OR: 1.04; 95% CI: 1.02-1.05; p<0.001) and FDR<1 (OR: 3.58; 95% CI: 2.03-6.31; p<0.001) were independent risk factors for femoral head necrosis.

CONCLUSION

Excessive preoperative FAV and FDR<1 are important risk factors for femoral AVN after open reduction, pelvic osteotomy, and femoral osteotomy for Tönnis grade IV DDH. For children with DDH with high dislocation and excessive FAV, clinicians should fully evaluate their condition and design more personalized treatment programs to prevent AVN.

The protective role of vitamins C and E in steroid-induced femoral head osteonecrosis: An experimental study in rats

OBJECTIVES

This study aimed to determine whether vitamin C (VC) and vitamin E (VE) can effectively protect the femoral head and reduce the risk of developing osteonecrosis in rats that have been treated with steroids.

MATERIALS AND METHODS

The study was conducted on 30 young adult male Sprague-Dawley rats (mean weight: 356±18 g; range, 330 to 375 g), which were randomly assigned to one of five groups. The control group received saline solution, while the other groups were given lipopolysaccharide/methylprednisolone (LPS/MPS) to induce osteonecrosis. Three groups in which osteonecrosis was induced were also intraperitoneally administered either VC, VE, or both once a day for four weeks. Intracardiac blood samples were taken at the end of the fourth week for biochemical examination, and the rats were then sacrificed under general anesthesia. After sacrification, right femurs were removed for histopathological, immunohistochemical, and radiologic examinations.

RESULTS

The results showed that the mean trabecular number increased significantly in the VC+VE group. There was a substantial decrease observed in the mean trabecular separation within the LPS/MPS group compared to the control group, although trabecular separation decreased in all three vitamin groups compared to the LPS/MPS group. The surface area/bone volume was significantly increased in the VC+VE group compared to the LPS/MPS group. Histological, immunohistochemical, and radiological examinations showed that the administration of VC and VE significantly reduced oxidative stress, inflammation, and microvascular dysfunction in rats with steroid-induced femoral head osteonecrosis.

CONCLUSION

This study suggests that VC, VE, and particularly VC+VE have a protective effect on the femoral head in rats with steroid-induced femoral head osteonecrosis. These findings may lead to new treatment options for patients.

Extracellular vesicles from human umbilical cord mesenchymal stem cells prevent steroid-induced avascular necrosis of the femoral head via the PI3K/AKT pathway

Extracellular vesicles (EVs) secreted by human umbilical cord mesenchymal stem cells (hucMSC) have excellent therapeutic potential for many diseases. The aim of this study was to define the role of hucMSC-EVs in the prevention and treatment of steroid-induced avascular necrosis of the femoral head (SANFH). After establishing the SANFH rat model, the effects of hucMSC-EVs were assessed by measuring the microstructure of the femoral head using HE staining, micro-computed tomography (micro-CT), and TUNEL staining. The administration of hucMSC-EVs caused a significant reduction to glucocorticoids (GCs)-induced osteoblast apoptosis and empty lacuna of the femoral head, while effectively improving the microstructure. HucMSC-EVs rescued the deactivation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway induced by GCs, and reversed the proliferation and migration of osteoblasts inhibited by GCs. In addition, hucMSC-EVs attenuated the inhibitory effects of GCs on rat osteoblast osteogenesis, angiogenesis of endothelial cells, and prevented osteoblast apoptosis. However, the promoting effects of hucMSC-EVs were abolished following the blockade of PI3K/AKT on osteoblasts. hucMSC-EVs were found to prevent glucocorticoid-induced femoral head necrosis in rats through the PI3K/AKT pathway.

Effects of Puerarin-Loaded Tetrahedral Framework Nucleic Acids on Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) is recognized as a common refractory orthopedic disease that causes severe pain and poor quality of life in patients. Puerarin (Pue), a natural isoflavone glycoside, can promote osteogenesis and inhibit apoptosis of bone mesenchymal stem cells (BMSCs), demonstrating its great potential in the treatment of osteonecrosis. However, its low aqueous solubility, fast degradation in vivo, and inadequate bioavailability, limit its clinical application and therapeutic efficacy. Tetrahedral framework nucleic acids (tFNAs) are promising novel DNA nanomaterials in drug delivery. In this study, tFNAs as Pue carriers is used and synthesized a tFNA/Pue complex (TPC) that exhibited better stability, biocompatibility, and tissue utilization than free Pue. A dexamethasone (DEX)-treated BMSC model in vitro and a methylprednisolone (MPS)-induced ONFH model in vivo is also established, to explore the regulatory effects of TPC on osteogenesis and apoptosis of BMSCs. This findings showed that TPC can restore osteogenesis dysfunction and attenuated BMSC apoptosis induced by high-dose glucocorticoids (GCs) through the hedgehog and Akt/Bcl-2 pathways, contributing to the prevention of GC-induced ONFH in rats. Thus, TPC is a promising drug for the treatment of ONFH and other osteogenesis-related diseases.

The effects of prophylactic tadalafil use on VEGF expression in the rabbit model of steroid-induced femoral head avascular necrosis

OBJECTIVE

The purpose of this study was to examine the effect of prophylactic tadalafil use on a steroid-induced femoral head avascular necrosis model in terms of microscopic, imaging, and molecular biological changes.

METHODS

Twenty-four New Zealand rabbits were divided into 3 equal groups. Eight rabbits were designated as the control group and did not receive treatment. Rabbits in group 1 (G1) received 0.1 mg/kg Escherichia coli lipopolysaccharide (LPS) intravenously and 40 mg/ kg methylprednisolone sodium succinate (MP) was administered intramuscularly for 3 days consecutively. Rabbits in group 2 (G2) were given 5 mg/kg tadalafil orally for 10 consecutive days. Starting on the eighth day, 0.1 mg/kg LPS was given, and following this 40 mg/kg MP injections were administered for 3 days. All animals were sacrificed 3 weeks after the final MP injection. Magnetic resonance imaging was performed, and bilateral femora were harvested. Half of the femoral head was stored for Vascular Endothelial Growth Factor (VEGF) examination with Western blot analysis. The other half was examined microscopically for the presence of osteonecrosis.

RESULTS

In G1, 15 out of 16 hips (93%) of the 8 rabbits had osteonecrosis compared to 8 out of 12 hips (67%) of 6 rabbits in G2 (P > .05). The VEGF expression in G2 was significantly higher than in the control group and G1 (P < .05 and P < .001, respectively). There was no significant difference in VEGF expression between the control group and G1 (P > .05).

CONCLUSION

This study has shown us that femoral head osteonecrosis can be reliably induced with LPS and corticosteroid, as described in the literature. Prophylactic tadalafil use did not decrease the occurrence of osteonecrosis significantly. However, it significantly increased VEGF expression in the femoral head independent of the effects of steroids and LPS.

[Expert consensus on clinical drug prevention and treatment of osteonecrosis of the femoral head(2022)]

With the in-depth understanding of osteonecrosis of femoral head (ONFH), and more and more patients seeking medical treatment in the early stage of the disease, surgical treatment of femoral head necrosis alone is no longer sufficient for the current treatment of patients' demand, how to rationally and effectively apply drugs to strengthen the early prevention and treatment of femoral head necrosis and delay the progression of disease is becoming more and more important. This article combines the latest expert consensus and evidence-based medical evidence on the principles of ONFH diagnosis and treatment in Chinese and Western medicine at home and abroad, combined with domestic actual clinical application experience, and is organized by experts from Association Related to Circulation Osseous Chinese Microcirculation Society (CSM-ARCO) to write this consensus, focusing on the types of ONFH drugs, the characteristics, safety, rationality and basic principles of drug use provide reference opinions for the safe, reasonable, standardized and effective drug use of medical institutions at all levels. This consensus is only an expert guideline based on literature and clinical experience, not as a requirement for mandatory implementation, let alone as a legal basis. The clinical practice could be tailored to the actual local conditions to develop appropriate prevention and treatment measures for patients.

Ginkgo biloba L. extract prevents steroid-induced necrosis of the femoral head by rescuing apoptosis and dysfunction in vascular endothelial cells via the PI3K/AKT/eNOS pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ginkgo biloba L. extract (EGb) is one of the world's most extensively used herbal medicines. Due to the diverse pharmacological properties of EGb, it has been used in the treatment of neurological illnesses, as well as cardiovascular and cerebrovascular ailments. However, the effect and pharmacological mechanism of EGb on steroid-induced necrosis of the femoral head (SINFH) are still unclear.

AIM OF THE STUDY

SINFH remains a challenging problem in orthopedics. Previous investigations have shown that EGb has the potential to reduce the occurrence of SINFH. The goal was to determine the effect and mechanism of EGb in preventing SINFH by inhibiting apoptosis and improving vascular endothelial cells (VECs) functions.

MATERIALS AND METHODS

CCK-8, nitric oxide (NO) production and flow cytometry were used to determine the cell apoptosis and function. The scratch and angiogenesis tests assessed migration and tube formation. Western blot analysis detected the expressions of apoptosis-related proteins and PI3K/AKT/eNOS pathway-related proteins. Apoptosis and angiogenesis were also detected treated with the inhibitors. A mouse model of SINFH was established. Paraffin section was used to determine the necrotic pathology and apoptosis. Vessels in the femoral heads were assessed by immunofluorescence staining.

RESULTS

When stimulated by methylprednisolone (MPS), cell viability, NO generation and tube formation were decreased, the apoptotic rate increased. Simultaneously, MPS decreased the expression levels of p-PI3K, p-AKT, and p-eNOS. EGb increased the expression levels of these proteins, restrained apoptosis, and restored cell functions. The addition of the inhibitors decreased anti-apoptotic effect and angiogenesis. In addition, when compared to the model mice, there were fewer empty lacunae and normal trabecular arrangement after taking different doses of EGb. The protective effect was also confirmed by the vascular quantitative analysis in vivo.

CONCLUSION

This study established that EGb increased endothelial cell activity and inhibited apoptosis and function loss induced by MPS, elucidating the effect and molecular mechanism of EGb on early SINFH.

Evaluation of avascular necrosis risk factors after closed reduction for developmental dysplasia of the hip before walking age

Avascular necrosis (AVN) of the femoral head is one of the most important complications after closed reduction and spica cast application in developmental dysplasia of the hip (DDH) treatment. This study aims to put forth the impact of closed reduction age and other factors which can cause AVN. Inclusion criteria of the study were: closed reduction and spica cast application before walking age (12 months) and minimum 2 years duration of follow-up. The presence of femoral head ossific nucleus, International Hip Dysplasia Institute (IHDI) score, acetabular indices and AVN were evaluated from radiographies. Hip abduction angles were evaluated on CT images. The absence of the ossific nucleus at the closed reduction time and preoperative IHDI grade were not significant risk factors for AVN (respectively OR = 2.83; 95% CI, 0.99-8.07; P = 0.052; OR = 2.5; 95% CI, 0.85-7.32; P = 0.094). For the patients older than 10 months, (1) the absence of the ossific nucleus was a significant risk factor for grade 2 or higher AVN according to the Bucholz Ogden criteria (P = 0.020) and (2) the higher preoperative IHDI grade (IHDI 3-4) was a significant risk factor for AVN (P = 0.032). AVN of the femoral head was a significant risk factor for fair or poor clinical outcome (P = 0.001). It is not reasonable to wait for radiological visibility of the ossific nucleus to prevent femoral head AVN before applying closed reduction and spica cast, irrespective of the age interval.

Soluble epoxide hydrolase inhibitor can protect the femoral head against tobacco smoke exposure-induced osteonecrosis in spontaneously hypertensive rats

Exposure to tobacco smoke (TS) has been considered a risk factor for osteonecrosis of the femoral head (ONFH). Soluble epoxide hydrolase inhibitors (sEHIs) have been found to reduce inflammation and oxidative stress in a variety of pathologies. This study was designed to assess the effect of sEHI on the development of ONFH phenotypes induced by TS exposure in spontaneously hypertensive (SH) rats. SH and normotensive Wistar Kyoto (WKY) rats were exposed to filtered air (FA) or TS (80 mg/m3 particulate concentration) 6 h/day, 3 days/week for 8 weeks. During this period, sEHI was delivered through drinking water at a concentration of 6 mg/L. Histology, immunohistochemistry, and micro-CT morphometry were performed for phenotypic evaluation. As results, TS exposure induced significant increases in adipocyte area, bone specific surface (BS/BV), and trabecular separation (Tb.SP), as well as significant decreases in bone mineral density (BMD), percent trabecular area (Tb.Ar), HIF-1a expression, bone volume fraction (BV/TV), trabecular numbers (Tb.N), and trabecular thickness (Tb.Th) in both SH and WKY rats. However, the protective effects of sEHI were mainly observed in TS-exposed SH rats, specifically in the density of osteocytes, BMD, Tb.Ar, HIF-1a expression, BV/TV, BS/BV, Tb.N, and Tb.SP. Our study confirms that TS exposure can induce ONFH especially in SH rats, and suggests that sEHI therapy may protect against TS exposure-induced osteonecrotic changes in the femoral head.

Can formation of avascular necrosis really be prevented in Delbet type 2 femoral neck fractures?

BACKGROUND

Fractures of proximal femur are rarely seen in childhood. These fractures can result in serious complications such as avascular necrosis (AVN), coxa vara, and early closure of the femoral epiphysis. The aim of this study is to investigate retrospectively the Delbet type 2 fractures that are commonly seen and has high rates of AVN.

METHODS

Forty-two patients whose Delbet type 2 fractures were treated in our hospital between January 2009 and June 2018 were analyzed. The patients' mechanism of fracture formation, displacement of the fracture, presence of accompanying injuries, timing of surgery, open or closed reduction, whether the screws cross the epiphyseal growth plate epiphyseal line, and AVN data were analyzed retrospectively.

RESULTS

Of the 42 screened patients, 34 patients with complete follow-up graphs and files were included in the study. The mean age of the patients was 11.02 years (1-17 years old), and the mean follow-up time was 40.82 months (range 24 to 98 months). When the follow-up radiographs of the patients were examined, it was found that AVN in 9 patients (26.5%), coxa vara in 2 patients (5.9%), and non-union in 1 patient (2.9%). The AVN rate was significantly higher in patients with high-energy injuries and high fracture displacement at baseline (p=0.034 and p=0.047, respectively).

CONCLUSION

According to our findings in Delbet type 2 fractures, other than the severity of the trauma and the initial displacement of the fracture, factors related to the treatment process do not have a significant effect on the development of AVN. Age was not determined as a risk factor for the development of AVN in these patients.

Exosomes Secreted from Hypoxia-Preconditioned Mesenchymal Stem Cells Prevent Steroid-Induced Osteonecrosis of the Femoral Head by Promoting Angiogenesis in Rats

Recent studies have suggested that exosomes exert similar therapeutic effects to those of mesenchymal stem cells (MSCs) in regenerative medicine and MSCs-derived exosomes exhibit therapeutic effects on steroid-induced osteonecrosis of the femoral head (ONFH). Furthermore, reparative functions of exosomes from MSCs are enhanced by hypoxia treatment of the cells. However, there are no related reports about whether exosomes derived from hypoxia-preconditioned MSCs could show better therapeutic effects on steroid-induced ONFH. In vitro, we investigated the effects of hypoxia precondition on exosomes derived from bone marrow mesenchymal stem cells (BMMSCs) from rats and the proangiogenic ability of exosomes derived from hypoxia-preconditioned BMMSCs. In vivo, we investigated the role of exosomes from hypoxia-preconditioned BMMSCs on angiogenesis and protecting osteonecrosis in a rat ONFH model. We found that the potential of the proangiogenic ability of exosomes derived from hypoxia-preconditioned BMMSCs was higher than exosomes derived from BMMSCs cultured under normoxia. Exosomes derived from hypoxia-preconditioned BMMSCs significantly promoted proliferation, migration, vascular endothelial growth factor (VEGF) expression, and tube formation of human umbilical vein endothelial cells (HUVECs) compared with exosomes derived from BMMSCs cultured under normoxia. Administration of exosomes derived from hypoxia-preconditioned BMMSCs significantly prevented bone loss and increased vessel volume in the femoral head compared with exosomes derived from BMMSCs cultured under normoxia. Taken together, our data suggest that exosomes derived from hypoxia-preconditioned BMMSCs exert better therapeutic effects on steroid-induced ONFH by promoting angiogenesis and preventing bone loss.

[Expert consensus on prevention and treatment strategies for osteonecrosis of femoral head during the prevention and control of novel coronavirus pneumonia (2020)]

Novel coronavirus pneumonia is a new type of respiratory infectious disease that has rapidly spread in many countries or regions around the world. The World Health Organization (WHO) named it "coronavirus disease 2019 (COVID-19)". Glucocorticoids (GC) have certain application value in patients with COVID-19, but they need to be used with caution and strict indications and dosage. Application of large doses of GC can also cause osteonecrosis of femoral head (ONFH). On the basis of the latest literature and evidence-based medical evidence on the fight against COVID-19 epidemic and steroid ONFH diagnosis and treatment, the Bone Circulation and Osteonecrosis Professional Committee, Shockwave Medical Specialty Committee of Chinese Research Hospital Association organized Chinese bone necrosis related experts to jointly write this consensus, focusing on the prevention strategy and the protective management measures in the ONFH diagnosis and treatment process during the prevention and control of COVID-19, which can provide reference for hospitals at all levels to carry out early prevention and treatment of ONFH.

Effects of erythropoietin for precaution of steroid-induced femoral head necrosis in rats

BACKGROUND

Steroids such as glucocorticoid have been widely used for their excellent anti-inflammatory, anti-immune, and anti-shock properties. However, the long-term use in high doses has been found to cause necrosis of femoral head and other serious adverse reactions. Thus, it is of great importance to safely use these medications on patients without inducing bone necrosis.

METHODS

In this preclinical study, we examined the effects of erythropoietin (EPO) to attenuate the induction of steroid-induced femoral bone necrosis using rats to build up the in-vivo models. Rats were randomly divided into three groups: negative control group (group A), disease group (group B), and EPO group (group C). 20 mg/kg methylprednisolone was administrated into group B and group C for 6 weeks with two intramuscular injections per week per rat. Group C was further given daily intraperitoneal injections of rHuEPO during this period. Group A received only injection of saline at the same schedule. 12 weeks after the initial drug administration, the rats' femoral tissues were harvested for HE staining, immunohistochemistry studies for PECAM-1(also CD31) expression and Western Blotting for VEGF expression.

RESULTS

Histology studies showed that compared with the disease group, EPO group had significant improvement and bone morphology being much closer to the negative control group. Immunohistochemical studies revealed that EPO group had statistically much more expression of PECAM-1 than the other groups did. Western Blot demonstrated that the EPO group had significantly higher VEGF expression than the disease group.

CONCLUSION

Results suggested that simultaneous injection of EPO could partially prevent steroid-induced ANFH.

Pharmacological interventions for the prevention of insufficiency fractures and avascular necrosis associated with pelvic radiotherapy in adults

BACKGROUND

Pelvic radiotherapy is a treatment delivered to an estimated 150,000 to 300,000 people annually across high-income countries. Fractures due to normal stresses on weakened bone due to radiotherapy are termed insufficiency fractures. Pelvic radiotherapy-related interruption of the blood supply to the hip is termed avascular necrosis and is another recognised complication. The reported incidences of insufficiency fractures are 2.7% to 89% and risk of developing avascular necrosis is 0.5%. These complications lead to significant morbidity in terms of pain, immobility and consequently risk of infections, pressure sores and mortality.

OBJECTIVES

To assess the effects of pharmacological interventions for preventing insufficiency fractures and avascular necrosis in adults over 18 years of age undergoing pelvic radiotherapy.

SEARCH METHODS

We performed electronic literature searches in the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and DARE to 19 April 2017. We also searched trial registries. Further relevant studies were identified through handsearching of citation lists of included studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or non RCTs with concurrent comparison groups including quasi-RCTs, cluster RCTs, prospective cohort studies and case series of 30 or more participants were screened. We included studies assessing the effect of pharmacological interventions in adults over 18 years of age undergoing radical pelvic radiotherapy as part of anticancer treatment for a primary pelvic malignancy. We excluded studies involving radiotherapy for bone metastases. We assessed use of pharmacological interventions at any stage before or during pelvic radiotherapy. Interventions included calcium or vitamin D (or both) supplementation, bisphosphonates, selective oestrogen receptor modulators, hormone replacement therapy (oestrogen or testosterone), denosumab and calcitonin.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We contacted study authors to obtain missing data. Data were to be pooled using the random-effects model if study comparisons were similar, otherwise results were to be reported narratively.

MAIN RESULTS

We included two RCTs (1167 participants). The first RCT compared zoledronic acid with placebo in 96 men undergoing pelvic radiotherapy for non-metastatic prostate cancer.The second RCT had four treatment arms, two of which evaluated zoledronic acid plus adjuvant androgen suppression compared with androgen suppression only in 1071 men undergoing pelvic radiotherapy for non-metastatic prostate cancer.Both studies were at a moderate to high risk of bias and all evidence was judged to be of very low certainty.The studies provided no evidence on the primary outcomes of the review and provided limited data in relation to secondary outcomes, such that meta-analyses were not possible. Both studies focused on interventions to improve bone health in relation to androgen deprivation rather than radiation-related insufficiency fractures and avascular necrosis. Few fractures were described in each study and those described were not specific to insufficiency fractures secondary to radiotherapy. Both studies reported that zoledronic acid in addition to androgen deprivation and pelvic radiotherapy led to improvements in BMD; however, the changes in BMD were measured and reported differently. There was no available evidence regarding adverse effects.

AUTHORS' CONCLUSIONS

The evidence relating to interventions to prevent insufficiency fractures and avascular necrosis associated with pelvic radiotherapy in adults is of very low certainty. This review highlights the need for prospective clinical trials using interventions prior to and during radiotherapy to prevent radiation-related bone morbidity, insufficiency fractures and avascular necrosis. Future trials could involve prospective assessment of bone health including BMD and bone turnover markers prior to pelvic radiotherapy. The interventions for investigation could begin as radiotherapy commences and remain ongoing for 12 to 24 months. Bone turnover markers and BMD could be used as surrogate markers for bone health in addition to radiographic imaging to report on presence of insufficiency fractures and development of avascular necrosis. Clinical assessments and patient reported outcomes would help to identify any associated adverse effects of treatment and quality of life outcomes.

Dynamic hip system blade versus cannulated compression screw for the treatment of femoral neck fractures: A retrospective study

OBJECTIVE

The aim of this study was to compare clinical outcomes of patients with femoral neck fractures treated with the dynamic hip system blade (DHS-BLADE) or cannulated compression screws.

METHODS

Eighty-six patients with femoral neck fractures were treated by closed reduction internal fixation with a DHS-BLADE (n = 42; 18 males and 24 females; mean age: 56.3 years (37-87)) or cannulated compression screws (n = 44; 20 males and 24 females; mean age: 53.8 years (26-83)) between March 2011 and August 2013. The groups were compared with Harris hip score, operation time, surgical blood loss, incision size, hospital stay, and related complications.

RESULTS

The average follow-up time was 27 months (range, 24-36 months). There was no significant difference for the operation time, incision size, hospital stay, and Harris hip score between the groups. Also, no statistically significant differences in the rates of nonunion (4.5% vs. 0) and avascular necrosis of the femoral head (9.1% vs. 7.1%) were observed. However, the screw group experienced significantly less surgical blood loss (32.4 ± 24.7 ml) than the blade group (87.2 ± 46.6 ml; P = 0.041). The incidence of femoral neck shortening above 10 mm in the screw group was significantly higher than that in the blade group (15.9% vs. 2.4%, P = 0.031). The blade group had a significantly lower incidence of screw migration than the screw group (4.8% vs. 22.7%, P = 0.016).

CONCLUSION

The DHS-BLADE and cannulated compression screws might be equally effective in terms of postoperative fracture union. However, the DHS-BLADE has advantages over cannulated compression screws for preventing femoral neck shortening, screw migration, and cut-out.

LEVEL OF EVIDENCE

Level III, Therapeutic study.

Research in the precaution of recombinant human erythropoietin to steroid-induced osteonecrosis of the rat femoral head

Objective

To elucidate the effects of recombinant human erythropoietin (rHuEPO) on steroid-induced osteonecrosis of the femoral head in rats.

Methods

Twenty-four adult Wistar rats were randomly divided into three groups of eight rats each. The rats in the positive control group were injected with dexamethasone at 1 mg/kg twice a week for 5 weeks. The rats in the negative control group were injected with sodium chloride alone. The rats in the experimental group were injected with dexamethasone at 1 mg/kg twice a week for 5 weeks and rHuEPO (500 u/d/kg) daily for 5 weeks. The femoral head on one side was examined by hematoxylin and eosin staining, and that on the other side was examined by CD31 staining of the capillaries.

Results

Hematoxylin and eosin staining in the positive control group showed that the bony trabeculae had become obviously narrow and sparse with discontinuity of the integrity. The integrity of the trabeculae was better in the experimental group than positive control group. The CD31 expression was lower in the positive control group than in the other two groups.

Conclusion

rHuEPO can effectively prevent osteocyte apoptosis, delaying or decreasing osteonecrosis of the femoral head.

Prevention of steroid-induced osteonecrosis of femoral head in systemic lupus erythematosus by anti-coagulant

Although osteonecrosis of femoral head (ONF) is one of the serious complications in systemic lupus erythematosus (SLE) associated with corticosteroid therapy, there has been few trials of prevention of ONF described. We aimed to prevent ONF in steroid-treated SLE patients using anticoagulant, warfarin, conducting a multicenter prospective study. Sixty newly diagnosed SLE patients requiring 40 mg/day or more prednisolone were alternately assigned to either of two groups; a warfarin group and a control one. Warfarin (1 ∼ 5 mg/day) was started together with the beginning of steroid therapy and continued at least for three months. Patients were observed for the development of silent ONF by magnetic resonance imaging (MRI) and symptomatic ONF by plain radiography for over five years. The warfarin group consisted of 31 patients (62 hips) and the control one 29 patients (58 hips). Silent ONF developed in 13 hips (21%) and 19 hips (33%) in the warfarin group and the control group, respectively ( P = 0.13). On the other hand, warfarin tended to prevent symptomatic ONF; only three hips of 62 (4.8%) in the warfarin group and eight hips of 58 (14%) in the control group ( P = 0.08) developed silent ONF. It was also found that silent ONF developed, if it did, very early; within three months in 16 of 18 patients (89%). Among risk factors for silent ONF, steroid pulse therapy was most outstanding and it seemed to overcome the effect of warfarin. Taken together, for the time being, anticoagulant therapy, if not significantly sufficient, may be of use for the prevention of steroid-induced ONF in SLE. We consider that this study added to important evidence for the pathogenesis and prevention of ONF.

Lithium prevents rat steroid-related osteonecrosis of the femoral head by β-catenin activation

This study explored the use of lithium to prevent rat steroid-related osteonecrosis of the femoral head (ONFH) through the modulation of the β-catenin pathway. ONFH was induced by methylprednisolone combined with lipopolysaccharide, and serum lipids were analyzed. ONFH was detected by hematoxylin-eosin staining. Micro-CT-based angiography and bone scanning were performed to analyze vessels and bone structure, respectively. Immunohistochemical staining for peroxisome proliferator-activated receptor gamma (PPARγ), bone morphogenetic protein-2 (BMP-2), and vascular endothelial growth factor (VEGF) was analyzed. Protein levels of phospho-glycogen synthase kinase-3β at Tyr-216 (p-Tyr(216) GSK-3β), total glycogen synthase kinase-3β (GSK-3β) and β-catenin, as well as mRNA levels of GSK-3β and β-catenin in femoral heads, were assessed. The rate of empty bone lacunae in the femoral heads was lower in the lithium and control groups than in the model group. The lithium group showed preventive effects against steroid-related vessel loss by micro-CT-based angiography and VEGF staining. Lithium treatment improved hyperlipidemia and reduced PPARγ expression. Moreover, lithium improved steroid-related bone loss in micro-CT bone scans and BMP-2 staining analyses. Furthermore, local β-catenin was reduced in steroid-related ONFH, and lithium treatment increased β-catenin expression while reducing p-Tyr(216) GSK-3β levels. The local β-catenin pathway was inhibited during steroid-related ONFH. Lithium may enhance angiogenesis and stabilize osteogenic/adipogenic homeostasis during steroid-related ONFH in rats by activating the β-catenin pathway.

[Experimental study on preventive effect of Yougui drink on femoral head necrosis in rats under micro CT]

OBJECTIVE

To explore the preventive effect of Yougui drink on femoral head necrosis in rats under micro CT.

METHODS

Twenty-five SD rats were divided into steroid hormone group (group A, 10 rats ), Yougui drink group (group B,10 rats) and normal group (group C,5 rats)with random number table. Endotoxin were injected into abdominal cavity of rats in group A and B for 2 days, methylprednisolone sodium succinate were injected by gluteus for twice a week continued for 6 weeks; group B were gavaged by Yougui drink (veryday for 8 weeks; group C did not do any processing. All rats were killed on the 10th weeks,m icro CT were used to scan femoral head in vitro and preventive effect of Yougui drink (n femoral head necrosis in rats.

RESULTS

There was statistical significance in BMD, BV/TV, Tb.N, Tb, Th, Thb, Sp, BS/TV and DA but no significance in SMI between group A and B. Comparison between A and C, there was significant meaning in BMD, BV/TV, Tb.N, Tb, Th, Tb, Sp, BS/TV, DA and SMI.

CONCLUSION

Yougui drink on femoral head necrosis in rats under micro CT has preventive effect from BMD BV/TV, Tb.N, Tb, Th, Tb, Sp, BS/TV and DA.

Knee loading protects against osteonecrosis of the femoral head by enhancing vessel remodeling and bone healing

Osteonecrosis of the femoral head is a serious orthopedic problem. Moderate loads with knee loading promote bone formation, but their effects on osteonecrosis have not been investigated. Using a rat model, we examined a hypothesis that knee loading enhances vessel remodeling and bone healing through the modulation of the fate of bone marrow-derived cells. In this study, osteonecrosis was induced by transecting the ligamentum teres followed by a tight ligature around the femoral neck. For knee loading, 5 N loads were laterally applied to the knee at 15 Hz for 5 min/day for 5 weeks. Changes in bone mineral density (BMD) and bone mineral content (BMC) of the femur were measured by pDEXA, and ink infusion was performed to evaluate vessel remodeling. Femoral heads were harvested for histomorphometry, and bone marrow-derived cells were isolated to examine osteoclast development and osteoblast differentiation. The results showed that osteonecrosis significantly induced bone loss, and knee loading stimulated both vessel remodeling and bone healing. The osteonecrosis group exhibited the lowest trabecular BV/TV (p b 0.001) in the femoral head, and lowest femoral BMD and BMC (both p b 0.01). However, knee loading increased trabecular BV/TV (p b 0.05) as well as BMD (pb 0.05) and BMC (p b 0.01). Osteonecrosis decreased the vessel volume (pb 0.001), vessel number (pb 0.001) and VEGF expression (p b 0.01), and knee loading increased them (pb 0.001, pb 0.001 and p b 0.01). Osteonecrosis activated osteoclast development, and knee loading reduced its formation, migration, adhesion and the level of “pit” formation (pb 0.001, pb 0.01, pb 0.001 and pb 0.001). Furthermore, knee loading significantly increased osteoblast differentiation and CFU-F (both p b 0.001). A significantly positive correlation was observed between vessel remodeling and bone healing (both p b 0.01). These results indicate that knee loading could be effective in repair osteonecrosis of the femoral head in a rat model. This effect might be attributed to promoting vessel remodeling, suppressing osteoclast development, and increasing osteoblast and fibroblast differentiation. In summary, the current study suggests that knee loading might potentially be employed as a non-invasive therapy for osteonecrosis of the femoral head.

Open Reduction of Pediatric Femoral Neck Fractures Reduces Osteonecrosis Risk

Pediatric femoral neck fractures are rare injuries that are associated with a high risk of osteonecrosis of the femoral head. This study compared pediatric patients with fully displaced femoral neck fractures treated with either open reduction and internal fixation (ORIF) or closed reduction and internal fixation (CRIF). After institutional review board approval was obtained, the authors identified 53 patients who were treated for femoral neck fracture between 2003 and 2012. Inclusion criteria were as follows: (1) diagnosis of a fully displaced femoral neck fracture with no anatomic cortical contact; (2) age of at least 4 years; and (3) clinical/radiographic follow-up of at least 1 year. Medical records and radiographs were retrospectively reviewed. Excluded from the study were 16 patients who had fractures that were not fully displaced, 4 who were outside of the eligible age range, 1 who had insufficient radiographs, and 10 who had insufficient follow-up. Of the 22 patients included, 6 were treated with ORIF and 16 were treated with CRIF. Treatment groups were compared with Fisher's exact test for categorical outcome data and the Wilcoxon rank-sum test for continuous variables. There was a significantly (P=.051) greater occurrence of osteonecrosis after CRIF (50%) than after ORIF (0%). Further, patients who underwent ORIF had a higher (P=.009) quality of reduction, a higher (P=.046) rate of anatomic union, and fewer (P=.009) complications than those who underwent CRIF. Major complications occurred in significantly fewer (P=.015) hips after ORIF than after CRIF. No significant difference (P=.477) was seen between groups, according to the Ratliff assessment of final results. Fully displaced pediatric femoral neck fractures treated with ORIF had a significantly higher quality of reduction, with fewer complications, including osteonecrosis, than those treated with CRIF.

Key pathway to prevent the collapse of femoral head in osteonecrosis

OBJECTIVE

Osteonecrosis of the femoral head (ONFH) is a multifactorial disease, with unclear pathogenesis. The collapse of the femoral head is an important turning point in ONFH, especially for young patients. Many methods have been proposed, but the best treatment lacks consensus among orthopedic surgeons. Thus, understanding the collapse mechanism of the femoral head in ONFH is the key to a successful outcome of joint preservation. This review aims to provide an update of the collapse mechanism of the femoral head in ONFH and to focus on the most appropriate therapeutic strategies to adopt in clinical practice.

MATERIALS AND METHODS

We reviewed the international literature to identify studies focusing on ONFH and therapeutic options. PubMed, Medline and Cochrane Library databases were searched for English language papers.

RESULTS

An imbalance between bone resorption and bone formation as well as stress distribution on insufficient trabecular bone may be the most important collapse mechanism in ONFH.

CONCLUSIONS

Treatment to avoid femoral head collapse should focus on local effective mechanical support with modification of bone remodeling in the femoral head.

[Neglected traumatic dislocation of the hip treated with total hip arthroplasty: report of 2 cases]

Les luxations négligées de la hanche sont des lésions exceptionnelles. Elle concerne généralement des traumatismes graves, où les lésions ostéo-articulaires ne sont pas minutieusement recherchées, ou relayer au second plan. L’évolution inéluctable se fait vers la nécrose de la tête fémorale et la coxarthrose. L'arthroplastie permet de raccourcir cette évolution et de réinsérer rapidement ces patients.

Hypoxia-inducible factor prolyl hydroxylase inhibitor prevents steroid-associated osteonecrosis of the femoral head in rabbits by promoting angiogenesis and inhibiting apoptosis

The purpose of this study was to investigate the preventive effect of ethyl 3,4-dihydroxybenzoate(EDHB) on steroid-associated femoral head osteonecrosis(ONFH) in a rabbit model. New Zealand white rabbits were randomly divided into two groups (prevention group and model group), each containing 24 rabbits. Osteonecrosis was induced by lipopolysaccharide(LPS) combined with methylprednisolone(MPS). The prevention group received an intraperitoneal injection of EDHB at 50 mg/kg body weight every other day starting three days before establishing rabbit models of osteonecrosis, for a total of nine doses. Osteonecrosis was verified by haematoxylin-eosin (HE) staining. The expression of HIF-1α and VEGF was analyzed by immunohistochemistry. Angiogenesis, apoptosis and microstructural parameters were also analyzed. The rabbit models of osteonecrosis were successfully established and observed by HE staining. Histopathological observations indicated that EDHB reduced the rate of empty lacunae and the incidence of osteonecrosis. Immunohistochemical staining for HIF-1α and VEGF suggested that EDHB therapy inhibited degradation of HIF-1α and promoted expression of VEGF. Ink artery infusion angiography and microvessel density analysis revealed that there were more microvessels in the prevention group than in the model group. The TUNEL apoptosis assay suggested that EDHB intervention could reduce the number of apoptotic cells in avascular osteonecrosis of the femoral head. Micro-CT scanning indicated that the treatment group had better microstructural parameters than the model group. EDHB prevents steroid-associated osteonecrosis of the femoral head in rabbits by promoting angiogenesis and inhibiting apoptosis of bone cells and hematopoietic tissue.

Gastrodin prevents steroid-induced osteonecrosis of the femoral head in rats by anti-apoptosis

BACKGROUND

Gastrodin, as one of the major components extracted from the Chinese herb Gastrodia elata Bl., has many biologic effects, one of which is anti-apoptosis. Apoptosis is considered to be one of the pathogenetic mechanisms in steroid-induced osteonecrosis of the femoral head (ONFH). Therefore, we performed this study to investigate whether gastrodin has the potential to prevent steroid-induced ONFH.

METHODS

All 18 male adult Wistar rats were divided equally into three groups: the steroid group, the gastrodin+steroid group, and the control group. Osteonecrosis was induced by low-dose lipopolysaccharide and subsequent high-dose methylprednisolone. Histomorphometric method was used to determine the incidence of osteonecrosis. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay was performed to detect apoptotic index of osteocytes and osteoblasts. Real-time PCR and Western blotting were performed to detect mRNA and protein expression of Bax, Bcl-2, and Caspase-3. Fisher's exact probability test and one-way analysis of variance (ANOVA) with Turkey's post hoc test were used to examine significant differences between groups.

RESULTS

The incidence of osteonecrosis in the gastrodin+steroid group (16.7%) was significantly lower than that in the steroid group (83.3%). According to TUNEL assay, the apoptotic indices in the steroid group, the gastrodin+steroid group, and the control group were 91.1%, 27.1%, and 5.4%, respectively, and the differences were significant between groups. Compared with the control group and the gastrodin+steroid group, the mRNA and protein expression levels of Bax and Caspase-3 were significantly higher in the steroid group, but the Bcl-2 mRNA and protein expression levels were significantly lower.

CONCLUSION

Gastrodin could prevent steroid-induced ONFH by anti-apoptosis.

[Clinical observation of jianpi bushen formula to prevent collapse of osteonecrosis of femoral head]

To observe the clinical effect of Jianpi Bushen formula to prevent the collapse of osteonecrosis of femoral head (ONFH) of type phlegm and blood stasis obstructing the collaterals. 50 cases (including 73 hips) of non-collapse ONFH (ARCO I, II, III a) were selected from the out-patient department of orthopedic in Guang'anmen Hospital attached to China Academy of Chinese Medical Science. All the cases fit for diagnostic criteria were given Jianpi Bushen formula and followed up. Staging criteria was ARCO classification. Harris score evaluated the hip function. The mean follow-up time was 4.2 years (3-5.4 years). After a mean of 4.2 years (3-5.4 years) followed-up, 12 hips collapse occurred while 61 hips not (the non-collapse rate was 83.56%). Collapse did not occurred among the all 7 hips at stage ARCO I (the non-collapse rate was 100%). Among the 49 hips at stage ARCO II, 9 hips collapse occurred while 40 hips not (the non-collapse rate was 81.63%). Among the 17 hips at stage ARCO III a, 3 hips collapse occurred while 14 hips not (the non-collapse rate was 82.35%). Kaplan-Meier analysis showed the average survival time of non-collapse was 5 years (4. 8-5.2 years). The 3 year survival rate of non-collapse was 92.5%. The 4 year survival rate was 74% and the condition tended to be stability trend. The Harris score was 71.93 +/- 11.25 before treatment and 81.63 +/- 12.16 after treatment, significantly different. These results suggest that: Jianpi Bushen formula is an effective method for treating ONFH of type phlegm and blood stasis obstructing the collaterals. It can delay or prevent the collapse of femoral head and significantly improve the hip function.

Does dynamic immobilization reduce chondrocyte apoptosis and disturbance to the femoral head perfusion?

The purpose of this study is to investigate whether the dynamic hip immobilization is more favourable for lessening ischemic injury to the immature femoral head than a static immobilization. 152 Japanese white rabbits were divided into four groups randomly, and the hips were immobilized into "human" position (group A), "frog leg" position (group B) and "dynamic frog leg" position (group C). Group D was used as control. Ten rabbits in each group were killed, and the hip specimens were harvested at 1, 2, and 3 weeks after immobilization. Bcl-2/Bax expression balance and chondrocytes apoptosis were analyzed. The remaining eight rabbits in each group were used to measure the blood supply of capital femoral epiphysis by selective vascular perfusion with Indian ink. The Bcl-2/Bax expression ratio in group C was significantly increased than that in group A and B (p<0.001), while that was not significantly different from control group (p=0.0592). At three weeks after immobilization, the average apoptotic ratio was 36.7%, 45.8%, and 26.7% in group A, B and C, respectively (p<0.01). There was no significant difference between group C and normal control (p=0.0597). The perfusion ratio was 0.03±0.03, 0.03±0.02, and 0.08±0.03 in group A, B and C respectively, and 0.12±0.04 in control group (p<0.05). Thus, the dynamic immobilization model exhibited a relatively less chondrocytes apoptosis and disturbance to the femoral head perfusion than other immobilizations in vivo, which therefore may be useful for reducing avascular necrosis following the treatment of developmental dysplasia of the hip.

[Effect of Epimedium extract on osteoprotegerin and RANKL mRNA expressions in glucocorticoid-induced femoral head necrosis in rats]

OBJECTIVE

To investigate the effect of glucocorticoid on the expression levels of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa B ligand (RANKL) mRNAs in rat femoral head and the antagonistic effect of Epimedium, and explore the mechanism of Epimedium in preventing glucocorticoid-induced femoral head necrosis.

METHODS

Forty-eight adult SD rats were randomized into glucocorticoid group, Epimedium group and control group. In the former two groups, the rats received intramuscular injection of 12.5 mg prednisolone twice a week, and in Epimedium group, additional 1 ml/100 g aqueous Epimedium extract (equivalent to 0.1 g/ml of the crude drug) was administered intragastrically once daily. The control group received only intramuscular saline injection. After 4 weeks of treatment, osteonecrosis of the left femoral head was detected by HE staining, and the right femoral head was sampled for detection of OPG and RANKL mRNA expressions using real-time quantitative PCR.

RESULTS

In glucocorticoid, Epimedium and control groups, the mortality rate of the rats was 12.5% (2/16), 6.25% (1/16), 0 (0/16), and femoral head necrosis occurred at a rate of 71.43% (10/14), 26.67% (4/15), and 0 (0/16), respectively. In glucocorticoid group, the expression level of OPG mRNA was significantly lower, RANKL expression significantly higher, and OPG/RANKL ratio significantly lower than those in Epimedium and control groups (P<0.05). OPG, RANKL and their ratios showed no significant differences between Epimedium group and the control group.

CONCLUSION

Epimedium can prevent glucocorticoid-induced femoral head necrosis probably by antagonizing glucocorticiod-induced abnormal expressions of OPG and RANKL mRNA.

Anterior approach according to Ganz--surgical dislocation of hip joint

The surgical technique of an anterior approach to the hip joint according to Ganz is described. The procedure preserves the deep branch of the medial circumflex artery, which, combined with greater trochanter osteotomy, allows for safe hip joint dislocation without a risk of avascular necrosis of the femoral head. This approach makes it possible to inspect the femoral head and the entire acetabulum. It is suitable for the treatment of early stages of coxarthrosis.

[Final results of the operatively treated femoral neck fractures in children and adolescents]

BACKGROUND

Femoral neck fractures in children occur 130 times more seldom than in adult's population. According to specific vascularisation the most common complication is avascular necrosis (AVN) of the femoral head. Purpose of the study was the treatment's results analysis of the 15 children and adolescent's femoral neck fractures.

METHODS

15 patients at a mean age of 12.7 years (5-17 years) presenting with femoral neck fractures were analyzed. On the pre- and postoperatively X-rays we have determined the type of fracture in Delbet classification and compared femoral-neck angle with the healthy side. In the final clinical examination ROM, the equality of leg's length and quality of walking were checked. The results were determined in the Harris hip score and Ratliff score. We divided the patients into 3 groups that depended on the time of surgery: 1) operated up to 24 hours after injury (6 patients), 2) 24-72 hours post fracture (5), 3) after 72 hours (4).

RESULTS

10 fractures were classified to type 2, 3 fractures to type 3 according to Delbet scale (X-rays of 2 patients are missed). The final outcome after 7-163 months (57 on average) could be precised at 13 patients. Significant ROM decreasing was confirmed in 4 patients. The highest restriction was noticed in internal rotation (on average 14 degrees comparing with the healthy side). Other motions were slightly restricted. Inequality of limb's length amounted 0.5 cm on average. The average Harris hip score amounted 92.58 (76-100). The final results were assessed as very good at 8 patients, good at 4 and moderate in 1 patient. We haven't noticed bad results. AVN were suspected in 3 patients, 2 of them were scintigraphically confirmed.

CONCLUSIONS

In order to avoid AVN the most important thing is an early (up to 24 hours since the injury) anatomic reposition and proper bone fragments stabilization.

Vitamin E prevents steroid-induced osteonecrosis in rabbits

Background and purpose

Prevention of osteonecrosis after corticosteroid administration would be important. We examined the potential of vitamin E (α-tocopherol) to reduce the incidence of corticosteroid-induced osteonecrosis in an animal model.

Methods

Japanese white rabbits were divided into 2 groups; the control group was fed a normal diet and the experimental group was fed α-tocopherol-supplemented diet in which α-tocopherol (600 mg/kg diet) was added to the normal diet. To induce osteonecrosis, high-dose methylprednisolone acetate (MPSL) (20 mg/kg body weight) was injected once into the right gluteus medius muscle of all rabbits. 4 weeks after the injection of MPSL, the presence or absence of osteonecrosis of bilateral femurs was examined histopathologically. The tocopherol/cholesterol ratios were calculated. The plasma levels of thiobarbituric acid-reactive substances (TBARS) were measured.

Results

Alpha-tocopherol-supplemented diet reduced the incidence of osteonecrosis, which developed in 14 of 20 rabbits in the control group and 5 of 21 rabbits in the experimental group (p = 0.004). The tocopherol/cholesterol ratio was higher in the experimental group than in the control group after the α-tocopherol administration. The plasma TBARS level was lower in the experimental group than in the control group at 4 weeks after the MPSL administration.

Interpretation

Our findings may offer a new approach for the prevention of corticosteroid-induced osteonecrosis.

Optimal treatment of femoral neck fractures according to patient's physiologic age: an evidence-based review

For decades, the basic tenets of managing displaced femoral neck fractures have not changed, but the optimal treatment choice continues to be highly debated. The contemporary controversies associated with the treatment principles of displaced femoral neck fractures are distinct between young and old patients and are considered individually in this article about the current evidence. Although fixation constructs all seem to have similar complication rates, there is increasing evidence suggesting that total hip replacement improves patient functional outcomes for healthy, independent, elderly patients compared with hemiarthroplasty and should be considered as the treatment of choice for these patients.

[Preventing steroid-induced osteonecrosis of the femoral head with Liuwei dihuang pills and molecular mechanism]

OBJECTIVE

To evaluate the effects and the molecular mechanism of Liuwei dihuang pills in preventing steroid-induced osteonecrosis of the femoral head (ONFH) so as to provide an experimental basis for preventing ONFH clinically.

METHODS

Thirty-six adult Kunming mice (weighing 40-50 g, 46 g on average) were randomly divided into three groups (n=12): group A (control group), group B (model group) and group C (prevention group). In groups B and C, ONFH mice models were produced by intraperitoneal injection of horse serum at first (10 mL/kg) and a second injection of horse serum intraperitoneally (5 mL/kg) and prednisolone intramuscularly [45 mL/(kg x day), for 5 days] 2 weeks later. At the same time, the mice in group C were given Liuwei dihuang pills intragastrically [2 g/(kg x day)] and were given normal saline [10 mL/(kg x day)] in group B. In group A, mice were given normal saline intramuscularly and intragastrically as controls. The animals were sacrificed 2, 4, and 8 weeks after first treatment with prednisone, and femoral heads and livers were harvested to do histopathology analysis and apoptosis assay.

RESULTS

Other mice survived throughout the experiment period except two death at 7 and 11 days after second injection of horse serum intraperitoneally in group B and one death at 24 hours after second injection of horse serum intraperitoneally in group C. The appearance and shape of the femoral head and the surface of cartilages were all normal. The histological observation showed: normal structures of liver and femoral head were seen in group A at each time point; swelling liver cells with small fat vacuole, unclear structure of hepatic cords and narrower sinus hepaticus were seen, the bone trabeculae of femoral head was thin, sparse and collapsed in some regions and the changes became more obvious with time in group B; group C had similar results to group A. The percentage of empty osteocyte lacunae was significantly higher in group B than in groups A and C (P < 0.01). The osteoprotegerin expression significantly decreased and the osteoprotegerin ligand expression significantly increased in group B when compared with groups A and C (P < 0.01). Apoptosis analysis showed that the apoptosis index in group B was significantly higher than that in groups A and C (P < 0.01).

CONCLUSION

Liuwei dihuang pills can prevent steroid-induced ONFH by improving lipid metabolism, relieving bone lesion, and protecting against cell death.

[Effect of abducens orthosis combined with walker on developmental dysplasia of the hip]

OBJECTIVE

To evaluate the effect of abducens orthosis combined with walker on developmental dysplasia of the hip (DDH).

METHODS

A total of 126 patients (224 hips) with DDH aged 6-36 months in Xiangya Hospital was randomly divided into 2 groups: an orthosis combined with walker group and an improved hip frog cast fixation group. Seventy patients (130 hips) were treated by the orthosis combined with walker and 56 patients (94 hips) were treated by the improved hip frog cast fixation. We compared the effect and complications of the 2 groups.

RESULTS

The fineness rates of the orthosis combined with walker group and the improved hip frog cast fixation group were 89.2% and 90.4%, respectively, with no significant difference (P>0.05). The rate of femoral head osteonecrosis in the orthosis combined with walker group was significantly lower than that in the improved hip frog cast fixation group (1.5% vs. 5.3%,P<0.05), but the re-dislocation rate in the former was significantly higher than that in the latter (6.9% vs. 1.1 %, P<0.05).

CONCLUSION

Both methods are effective for DDH. Orthosis combined with walker has a lower proportion of femoral head osteonecrosis, but a higher proportion of re-dislocation.

Treatment of femoral neck fractures in young adults

Femoral neck fractures in physiologically young adults, which often result from high-energy trauma, are less common than intracapsular femoral neck fractures in elderly patients. They are associated with higher incidences of femoral head osteonecrosis and nonunion. Understanding the multiple factors that play a significant role in preventing these complications will contribute to a good outcome. Although achieving an anatomic reduction and stable internal fixation are imperative, other treatment variables, such as time to surgery, the role of capsulotomy, and the method of fixation remain debatable. Open reduction and internal fixation through a Watson-Jones exposure is the recommended approach. Definitive fixation can be accomplished with three cannulated or noncannulated cancellous screws. Capsulotomy in femoral neck fractures remains a controversial issue, and the practice varies by institution, region, and country. The timing of the open reduction and internal fixation is controversial. Until conclusive data are available through prospective, controlled studies, performing a capsulotomy followed by open reduction and internal fixation on an urgent basis is recommended. The goals of treating femoral neck fractures should include early diagnosis, early surgery, anatomic reduction, capsular decompression, and stable internal fixation.

Salvage of failed treatment of femoral neck fractures

The number of patients treated for femoral neck fractures continues to increase. Although most fractures will heal, reported rates of nonunion and osteonecrosis are cause for concern; therefore, implementation of effective salvage strategies is important. The choice of salvage strategy generally is guided by patient age, remaining bone quality, the status of the articular surface of the hip joint, and the viability of the femoral head. Nonunions in patients younger than 60 years are typically treated with valgus-producing osteotomies, which convert shear forces to compressive forces and have demonstrated relatively high union rates. The role of various vascularized and nonvascularized bone grafts remains undefined. Nonunions in patients older than 60 years are typically salvaged with some form of hip arthroplasty. Both hemiarthroplasty and total hip arthroplasty can be effective. Surgical challenges include osteopenic bone; bony defects from hardware; and contracted, scarred, and shortened limbs. Careful attention to detail during surgery is necessary to avoid complications and provide durable reconstructions in this setting.

Fractures of the femoral neck

Fractures of the femoral neck are increasing at an exponential rate as a result of the longevity of the general population. The Garden and Pauwels classifications both are routinely used to describe displacement and stability of femoral neck fractures. Osteonecrosis and nonunion remain problematic because of the compromised blood supply to the femoral head in displaced fractures. Nondisplaced fractures and displaced fractures in patients physiologically younger than 65 years are treated with closed or open reduction and internal fixation. Anatomic reduction is the single most important step in the treatment and fixation of these difficult fractures. Because of the higher complication rate in patients physiologically older than 65 years, a prosthetic replacement may be considered for the treatment of displaced fractures. In patients who are low-level community ambulators or nursing home ambulators with comorbidities and who are not expected to live more than 5 years after injury, a hemiprosthesis is indicated. In active, elderly patients physiologically older than 65 years who are expected to live longer than 5 years after injury, a total hip replacement is the treatment of choice. Total hip replacement relieves pain and allows faster rehabilitation than other forms of treatment in this age group. Patients with preexisting hip disease also are treated with total hip replacement. An algorithm that considers physiologic age and activity level of the patient is helpful when deciding whether to fix or replace the hip in a patient with a displaced femoral neck fracture. It is also useful in deciding what type of prosthesis to use. The treatment of femoral neck fractures remains complex and difficult. Because of the enormous burden of this injury, orthopaedists must improve results in the care of femoral neck fractures.

Preventive effects of puerarin on alcohol-induced osteonecrosis

Alcohol can induce adipogenesis by bone marrow stromal cells and may cause osteonecrosis of the femoral head. Currently, there are no medications available to prevent alcohol-induced osteonecrosis. We hypothesized puerarin, a Chinese herbal medicine with antioxidative and antithrombotic effects, can prevent alcohol-induced adipogenesis and osteonecrosis. Both bone marrow stromal cells (in vitro) and mice (in vivo) were treated either with ethanol or with ethanol and puerarin, with an untreated group serving as a control. In the in vitro study, the number of adipocytes, contents of triglycerides, and levels of PPAR gamma mRNA expression were decreased and alkaline phosphatase activity, contents of osteocalcin, and levels of osteocalcin mRNA expression were increased in cells treated with both alcohol and puerarin, compared with cells treated with alcohol only. In the in vivo study, marrow necrosis, fat cell hypertrophy and proliferation, thinner and sparse trabeculae, diminished hematopoiesis, and increased empty osteocyte lacunae in the subchondral region of the femoral head were observed in mice treated with alcohol. However, no such changes were seen in femoral heads of mice treated with alcohol and puerarin. The data suggest puerarin can inhibit adipogenic differentiation by bone marrow stromal cells both in vitro and in vivo and prevents alcohol-induced osteonecrosis in this model.

Pitavastatin may reduce risk of steroid-induced osteonecrosis in rabbits: a preliminary histological study

Several animal and human studies suggest pharmacological approaches may prevent steroid-induced osteonecrosis (ON). We asked whether the newly developed 3-hydroxymethyl-3-glutaryl-CoA (HMG-CoA) reductase inhibitor, pitavastatin, could prevent steroid-induced ON in rabbits. We injected 65 adult male Japanese white rabbits once with 20 mg/kg of methylprednisolone acetate into the right gluteus medius muscle. The rabbits were divided into two groups; one group of 35 rabbits received pitavastatins (PS), and the other group of 30 rabbits received no prophylaxis (CTR). Hematological examinations were performed just before the steroid injection (0 weeks) and at 1 and 2 weeks after steroid injection; both the femora and the humeri were histologically examined 2 weeks postinjection. The incidence of histologic changes consistent with early ON in the PS group (13 of 35; 37%) was lower in comparison to the CTR group (21 of 30; 70%). The size of the bone marrow fat cells in the PS group (56.6 +/- 10 microm) was smaller than those in the CTR group (60 +/- 4 microm). The data suggest pitavastatin has the potential to lower the incidence of steroid-induced ON in rabbits.

[Genetic analysis for prevention of steroid-induced osteonecrosis of the femoral head]

Idiopathic osteonecrosis of the femoral head (ION) is caused by disruption of blood flow. This disease often occurs in association with steroid treatment. The pathology of corticosteroid-induced ION is unclear, although abnormalities in the coagulation and fibrinolytic systems or in the lipid metabolism have been reported to be involved. We found the differences of gene polymorphism frequencies of ATP-binding casette, sub-family B, member 1 (ABCB1) C3435T, Apolipoprotein B (ApoB) C7623T and cAMP-response element binding protein-binding protein (CBP) (rs3751845) between ION cases and referent patients among those who were subjected to renal transplantation. For the prediction of ION, it is useful to analyze ABCB1 C3435T, ApoB C7623T and CBP (rs3751845) before the administration of steroids.

[Treatment of femoral neck fracture with cannulated screw fixation in young adults]

OBJECTIVE

To evaluate the clinical effect of cannulated screw on treatment of femoral neck fracture (FNF).

METHODS

Forty-two FNF patients were treated by using cannulated screw from January 2001 to December 2005. There were 22 males and 20 females with an average age of 41 years (19-59 years). Fracture was caused by traffic accident in 21 cases, by falling from height in 14 cases and by bruise in 7 cases. All cases were fresh fracture. According to Garden criterion for typing, 15 cases were classified as type I , 16 cases as type In and 11 cases as type IV. It was 7 hours to 15 days from injury to operation.

RESULTS

The patients were followed up for 1-6 years with an average of 2.5 years. The average fracture union time was 6.5 months. Three patients had ischemic necrosis of femoral head, and loosening and breakage of screw and rob was observed in 1 case. According to Brumback criterion for hip joint function, the result was excellent in 18 cases, good in 20 cases and bad in 4 cases, and the excellent and good rate was 90.4%.

CONCLUSION

Cannulated screw fixation is a good method to treat FNF in young adults. It can improve the rate of fracture union and reduce the rate of avascular necrosis of femoral head.

[Closed reduction in the treatment of developmental dysplasia of the hip]

One of the standard treatment methods for developmental dysplasia of the hip is closed reduction followed by immobilization in a hip spica cast. This treatment is performed before achievement of independent walking, under general anesthesia and with arthrographic control. Avoidance of forced reductions and immobilization of the hip with extreme positions is of utmost importance during the procedure. Development of avascular necrosis (AVN) of the femur head is the main parameter affecting the late outcome of the procedure. All modifiable factors should be influenced in favor of the patient to avoid AVN. This method appears to be satisfying with acceptable rates of AVN when applied by experienced pediatric orthopedic surgeons.

[Salter osteotomy: an overview]

Pelvic osteotomies are an integral part of treatment in developmental dysplasia of the hip after 18 months. This article focuses on the innominate osteotomy which was introduced by Richard Salter in 1961. Salter innominate osteotomy is a complete pelvic osteotomy that hinges on the symphysis pubis and results in anterolateral displacement of the acetabulum. The derotated acetabulum is held in place with a bone graft and fixed with Kirschner wires. Salter osteotomy has been performed over four decades and excellent short- and long-term results have been reported from different centers all over the world. Its success is closely related to appropriate patient selection and meticulous surgical technique with strict adherence to prerequisites.

[The course and treatment of avascular necrosis of the femoral head in developmental dysplasia of the hip]

Proximal femoral growth disturbance, commonly referred to as avascular necrosis (AVN) of the femoral head in the literature, is a potentially devastating complication in the treatment of developmental dysplasia of the hip (DDH). The early onset of debilitating degenerative changes in the hip joint when treatment options are limited remains the biggest fear. Controversy exists regarding the pathophysiology of this disorder, as well as exactly defining and diagnosing this problem. The natural history of AVN in the setting of DDH is very variable. Current practice concentrates primarily on prevention of this disorder, as there are no reliable ways to intervene at an early stage when changes are potentially reversible. Newer techniques using magnetic resonance imaging may have a role in early diagnosis of this condition before irreversible damage has occurred, and allow for interventions that will favorably affect the natural history of AVN. Treatment options for established AVN in DDH concentrate on improving the biomechanics of the proximal femur but unfortunately do not obviate the need for arthrodesis or arthroplasty at a later date.

Does unstable slipped capital femoral epiphysis require urgent stabilization?

Controversy exists regarding the role of early reduction and stabilization in the management of unstable slipped capital femoral epiphysis. It seems logical that early reduction and stabilization of an unstable slip might preserve the remaining blood supply to the epiphysis and reduce the incidence of avascular necrosis. Some studies have indeed shown lower rates of avascular necrosis following early reduction and stabilization, but others have shown the contrary. To try to resolve this disagreement, we conducted a retrospective review of slipped capital femoral epiphysis treated in Alder Hey Hospital over a 4-year period. We reviewed 117 consecutive slips in 82 children (43 boys and 39 girls, mean age 12 years), treated by internal fixation from 1998 to 2002. Mean follow-up was 18 months (range, 12-48 months). Sixteen cases (19%) were unstable at presentation. Avascular necrosis developed in eight of these, of which all but one were treated between 24 and 72 h after symptom onset. The eight unstable slips that did not develop avascular necrosis were treated either within 24 h (five children) or at 8 days (three children). Avascular necrosis did not develop in any of the stable slips. We recommend immediate stabilization of unstable slips presenting within 24 h. If this is not possible because of delayed presentation, we recommend deferring definitive management until at least a week has elapsed. This study supports the notion that there is a definite period of time during which medical intervention increases the risk of avascular necrosis and should be actively avoided. We term this period 'the unsafe window'.

Reduction of the potential for thermal damage during hip resurfacing

Resurfacing arthroplasty of the hip is being used increasingly as an alternative to total hip replacement, especially for young active patients. There is concern about necrosis of the femoral head after resurfacing which can result in fracture and loosening. Most systems use a cemented femoral component, with the potential for thermal necrosis of the cancellous bone of the reamed femoral head. We used thermal probes to record temperatures close to the cement-bone interface during resurfacing arthroplasty.

The maximum temperature recorded at the cement-bone interface in four cases was approximately 68°C which was higher than that reported to kill osteocytes. A modified surgical technique using insertion of a suction cannula into the lesser trochanter, generous pulsed lavage and early reduction of the joint significantly reduced the maximum recorded cancellous bone temperature to approximately 36°C in five cases (p = 0.014).

We recommend the modified technique since it significantly reduces temperatures at the cement-bone interface.

[Surgical treatment of hip dysplasia through the medial approach]

Open reduction of developmental hip dysplasia by the medial approach is one of the effective surgical treatment methods during early childhood. Although surgical approaches, fixation and follow-up methods may vary, successful results can be obtained by the algorithm involving the posteromedial approach and arthrographic evaluation. The aim of open reduction by the medial approach should be to obtain Tönnis grade I arthrographic reduction of the dysplastic hip and to maintain it. Avascular necrosis of the femoral head is a potential complication of this method. Even though actual evaluation of this problem requires monitoring patients until maturity, it is essential that special attention be given to the most effective factors (minimal invasive surgical technique, correct reduction, and appropriate position for fixation) for preventing this complication.

[Pavlik's method in developmental dysplasia of the hip]

One of the worst complications following treatment of developmental dysplasia of the hip is avascular necrosis. In the first half of the 20th century, the incidence of this problem reached up to 30% of treated children. To avoid this complication, Arnold Pavlik developed a new method in the late 1940s and called it a dynamic approach to treatment, which was based on the ingenious idea that the hip is an organ of movements and needs movement to be healed. Healing is accomplished by using stirrups as an aid to attaining flexion of the hips and knees, whereby the child achieves a normal hip nonviolently by himself. Pavlik's method spread slowly throughout the world and this literature review points out problems with this method, and summarizes the rates of success achieved and avascular necrosis reported by various authors.