Hypofibrinolysis, thrombophilia, osteonecrosis

Updating Osteonecrosis of the Femoral Head

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

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

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

Association of Nitric Oxide Synthase Polymorphism and Coagulopathy in Patients with Osteonecrosis of the Femoral Head

Genetic polymorphism of nitric oxide synthase (NOS) can cause reduction of nitric oxide (NO) levels and may be associated with osteonecrosis of the femoral head (ONFH). However, the association of coagulopathy and NOS polymorphism in ONFH patients has not been confirmed. Between November 2005 and October 2013, 155 patients with ONFH were recruited in the study of serum coagulation profiles and NOS polymorphism. Another 43 patients who had dysplasia, osteoarthritis, or trauma of hip joints were included as controls. PCR genotyping for the analysis of NOS 27-bp polymorphism in intron 4 was performed. The analysis of coagulation profiles included fibrinogen, fibrinogen degradation product (FDP), protein S, protein C, and anti-thrombin III. The results showed that 27-bp repeat polymorphism was significantly associated with ONFH (OR 4.32). ONFH patients had significantly higher fibrinogen, FDP, protein S, and anti-thrombin III levels than that of the controls. The incidence of coagulopathy was significantly higher in ONFH patients (73.2%), and the odds ratio increased from 2.38 to 7.33 when they had 27-bp repeat polymorphism. Patients with hyperfibrinogenemia, elevated FDP levels, and with the risk factor of alcohol or steroid use had significantly higher risks of bilateral hip involvement. This study demonstrated the presence of NOS polymorphism, and a resultant reduction in NO production was associated with coagulopathy, which in turn might contribute to higher risks of bilateral ONFH. Our data suggests that checking NOS polymorphism and coagulopathy may provide a new avenue in managing ONFH.

Atraumatic osteonecrosis of the humeral head: pathophysiology and current concepts of evaluation and treatment

The humeral head is considered the second most common site for osteonecrosis to occur after the femoral head. As seen in the femoral head, the circulatory implications characteristic of this condition are attributable to the interaction between a genetic predisposition and the exposure to certain risk factors. There is no consensus regarding the pathogenesis of osteonecrosis, yet the final common pathway results in disrupted blood supply, increased intraosseous pressure, and bone death. Disease staging using radiography and magnetic resonance imaging is predictive of disease progression and can help the orthopedic surgeon to guide treatment. Although there is a myriad of treatment modalities, there is a lack of high-quality evidence to conclude what is the most appropriate treatment option for each stage of humeral head osteonecrosis. Nonoperative treatment is the preferred option in early-stage disease, and it may prevent disease progression. Nonetheless, in some cases, disease progression occurs despite nonoperative measures, and surgical treatment is required. The purpose of this article is to provide an updated review of the available evidence on risk factors, diagnosis, and treatment of atraumatic humeral head osteonecrosis.

Association of MTHFR rs1801133 and homocysteine with Legg-Calvé-Perthes disease in Mexican patients

Background

Legg–Calvé–Perthes disease (LCPD) is the avascular osteonecrosis of the proximal femoral epiphysis. It is a rare disease of unclear etiology in children, although alterations in coagulation or the collagen gene have been described and could be associated with its etiology. Our objective was to evaluate the following alterations: COL1A1 (rs1107946, rs2412298), COL2A1 (rs121912891 and rs387106558), MTHFR rs1801133, CBS rs115742905, and PT rs1799963 and their relationship with LCPD.

Methods

DNA was obtained and genotyped by real-time PCR with TaqMan probes. Prothrombin (FII) and homocysteine (Hcy) were determined by a coagulometric method. The variables were described as mean and standard deviation or percentages, and genotypic and allelic distributions were analyzed using the Student's t-test. The Hardy–Weinberg equilibrium and OR were also used.

Results

We studied 23 patients with LCPD and 46 controls. We did not find any association of the MTHFR, CBS, PT, COL1A1, and COL2A1 genetic variants with LCPD. However, when adjusting the data with the Hcy values for the MTHFR C677T polymorphism, the C/C genotypes showed an association with the recessive model (p = 0.038), with susceptibility to LCPD.

Conclusion

No association was found with the CBS, PT, COL1A1, and COL2A1 genes. Nevertheless, our results suggest a significant link between moderately elevated Hcy levels and the MTHFR C677T polymorphism in a cohort of Mexican children with LCPD.

Quantile-specific heritability of plasminogen activator inhibitor type-1 (PAI-1, aka SERPINE1) and other hemostatic factors

BACKGROUND

Plasminogen activator inhibitor type-1 (PAI-1, aka SERPINE1) is a moderately heritable glycoprotein that regulates fibrin clot dissolution (fibrinolysis).

OBJECTIVES

Test whether the heritabilities (h2 ) of PAI-1 and other hemostatic factors are constant throughout their distribution or whether they are quantile-specific (i.e., a larger or smaller h2 depending on whether their concentrations are high or low).

METHODS

Quantile regression was applied to 5606 parent-offspring pairs and 5310 full siblings of the Framingham Heart Study. Quantile-specific heritability was estimated from the parent-offspring regression slope (βPO , h2  = 2βPO /(1+rspouse )) and the full-sib regression slope (βFS , h2  = {(1+8rspouse βFS )0.5 -1}/(2rspouse )).

RESULTS

Heritability (h2  ± SE) increased significantly with increasing percentiles of the offspring's age- and sex-adjusted PAI-1 distribution when estimated from βPO (plinear trend  = 0.0001): 0.09 ± 0.02 at the 10th, 0.09 ± 0.02 at the 25th, 0.16 ± 0.02 at the 50th, 0.29 ± 0.04 at the 75th, and 0.26 ± 0.08 at the 90th percentile of the PAI-1 distribution, and when estimated from βFS (plinear trend  = 6.5x10-7 ). There was no significant evidence for quantile-specific heritability for factor VII (plinear trend  = 0.35), D-dimer (plinear trend  = 0.08), tPA (plinear trend  = 0.74), or von Willebrand factor (plinear trend  = 0.79).

CONCLUSION

Higher mean plasma PAI-1 antigen concentrations tend to accentuate genetic effects (quantile-dependent expressivity), which is consistent with the greater reported differences in PAI-1 concentrations between rs1799889 SERPINE1 (4G/5G) genotypes in patients with osteonecrosis, meningococcal sepsis, obesity, prior myocardial infarction, deep vein thrombosis, and polycystic ovarian syndrome than in healthy controls. It is also consistent with the greater increases in PAI-1 concentrations in 4G-allele carriers than 5G/5G homozygotes following fibrinolytic treatment, low-salt intake, and high saturated fat intake.

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

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

Osteonecrosis of the Femoral Head: an Updated Review of ARCO on Pathogenesis, Staging and Treatment

Non-traumatic osteonecrosis of the femoral head (ONFH) usually affects adults younger than 50 years and frequently leads to femoral head collapse and subsequent arthritis of the hip. It is becoming more prevalent along with increasing use of corticosteroids for the adjuvant therapy of leukemia and other myelogenous diseases as well as management of organ transplantation. This review updated knowledge on the pathogenesis, classification criteria, staging system, and treatment of ONFH.

Osteotomies for avascular necrosis of the femoral head

BACKGROUND

In osteonecrosis of the femoral head (ONFH), blood supply is insufficient for the metabolic requirements of the bone. The initial management is conservative, and, in case of failure, surgery is indicated. Osteotomies aim to change the spatial position of the necrotic portion of the femoral head. This systematic review evaluates the effectiveness and safety of osteotomies for ONFH.

SOURCE OF DATA

The systematic review, organized, conducted and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, was performed on PubMed and Google Scholar. We analysed outcomes in term of Harris Hip Score, leg shortening, secondary collapse and blood loss. We also verified the percentage of patients who required total hip replacement (THR) after osteotomy for ONFH.

AREAS OF AGREEMENT

A total of 16 articles were selected, including 775 patients and 852 osteotomies [curved varus osteotomy in 369 (43.3%) patients; transtrochanteric rotational osteotomy in 435 (51.05%) patients; half wedge osteotomy in 48 (5.6%) patients]. There was an overall THR conversion rate of 31.5% (268 hips on 852 osteotomies).

AREAS OF CONTROVERSY

There were no prospective randomized trials, and the outcome measures employed were often heterogeneous.

GROWING POINTS

Approximately one-third of the osteotomies performed in cases of ONFH are converted to THR over a period of ~7 years. In older patients, primary THR should be considered, especially as the conversion to THR after osteotomy is technically demanding.

AREAS TIMELY FOR DEVELOPING RESEARCH

Randomized clinical studies should be conducted in order to define the parameters of the patient that can direct towards the most suitable osteotomic technique.

ARCO Consensus on the Pathogenesis of Non-traumatic Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head (ONFH) is a devastating disease frequently leading to femoral head collapse and hip arthritis. Specifically, non-traumatic ONFH primarily affects young and middle-aged adults. Although compromised local circulation of the femoral head seems to be pathognomonic for the disease, the pathogenesis is perplexing and continues to be an area of scrutiny and research. Comprehension of the pathogenesis is of crucial importance for developing and guiding treatments for the disease. Therefore, we provide an up-to-date consensus on the pathogenesis of non-traumatic ONFH.

Bone marrow mesenchymal stem cell-derived exosomes promote plasminogen activator inhibitor 1 expression in vascular cells in the local microenvironment during rabbit osteonecrosis of the femoral head

Background

Nontraumatic osteonecrosis of the femoral head (NONFH) is a highly disabling orthopedic disease in young individuals. Plasminogen activator inhibitor 1 (PAI-1) has been reported to be positively associated with NONFH. We aimed to investigate the dysregulating PAI-1 in bone marrow mesenchymal stem cells (BMMSCs) and vascular cells in rabbit steroid-induced NONFH.

Methods

To verify the hypothesis that BMMSCs could promote thrombus formation in a paracrine manner, we collected exosomes from glucocorticoid-treated BMMSCs (GB-Exo) to determine their regulatory effects on vascular cells. microRNA sequencing was conducted to find potential regulators in GB-Exo. Utilizing gain-of-function and knockdown approaches, we testified the regulatory effect of microRNA in exosomes.

Results

The expression of PAI-1 was significantly increased in the local microenvironment of the femoral head in the ONFH model. GB-Exo promoted PAI-1 expression in vascular smooth muscle cells and vascular endothelial cells. We also revealed that miR-451-5p in GB-Exo plays a crucial role for the elevated PAI-1. Moreover, we identified miR-133b-3p and tested its role as a potential inhibitor of PAI-1.

Conclusions

This study provided considerable evidence for BMMSC exosomal miR-mediated upregulation of the fibrinolytic regulator PAI-1 in vascular cells. The disruption of coagulation and low fibrinolysis in the femoral head will eventually lead to a disturbance in the microcirculation of NONFH. We believe that our findings could be of great significance for guiding clinical trials in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-020-01991-2.

Hormones and thrombosis: risk across the reproductive years and beyond

Endogenous and exogenous hormones have significant effects on coagulation and may tip the hemostatic balance toward thrombosis. The endogenous hormonal changes in pregnancy and polycystic ovary syndrome, and exogenous hormonal contraception, menopause replacement, and transgender cross-hormone replacement may increase thromboembolism risk. Using the lowest effective dose is critical for prevention, but once thrombosis occurs, anticoagulation may be required, in some, long term. We review the relative risk of thrombosis in these conditions, risk factors, and anticoagulation treatment and prevention. Implementation of lowest effective hormonal therapies, thrombosis reduction strategies, and current anticoagulation management are critical for optimal patient outcomes.

Effectiveness of Iloprost in the Treatment of Bone Marrow Edema

Background and objective

Bone marrow edema (BME) is a rare condition caused by insufficient osseous blood supply and may result in severe pain that has adverse effects on patients’ life. To date, various conservative treatments have been recommended for the treatment of BME, including analgesics, immobilization of the affected extremity, and iloprost infusion. The aim of this retrospective study was to investigate the effectiveness of parenteral iloprost therapy in the treatment of BME detected in different skeletal locations.

Materials and methods

This retrospective study included 23 patients (17 men and six women) with BME who were classified as stage I-III according to the Association Research Circulation Osseous (ARCO) classification. BME was localized to the proximal femur in 13 (56.5%), the distal femur in four (17.4%), tarsal bone in four (17.4%), and tibial plateau in two (8.7%) patients. The mean age of the patients was 46.7 years and all the patients were evaluated with the Visual Analog scale (VAS), Functional Mobility Scale (FMS), and MRI.

Results

A significant improvement was observed in the post-treatment VAS and FMS scores of all patients compared to their pre-treatment scores. Moreover, the edema regressed completely in 60.9% of the patients at three months of MRI control. No serious side effects were observed during the treatment in any of the patients. However, transient side effects including headache, arrhythmia, and flushing were observed in five patients.

Conclusion

The present study indicated that iloprost therapy is an effective and safe option in the treatment of BME patients, particularly in the reduction of severe pain that has adverse effects on patients’ social life, regardless of ARCO staging. Moreover, this therapy could be particularly useful in reducing pain, improving functional recovery, and achieving complete regression of the edema on MRI in ARCO stage I-II patients.

Association of Thrombophilic Factors in Pathogenesis of Osteonecrosis of Femoral Head in Indian Population

PURPOSE

Role of heritable blood clotting disorders, both thrombophilias and hypofibrinolysis in causing avascular necrosis (AVN) of femoral head have been studied in regions like Europe and U.S.A. This study was done to investigate the role of heritable thrombophilias in ethnic Indian population.

MATERIALS AND METHODS

A case control study of 150 patients (100 cases and 50 age and sex matched controls) of Indian Ethnicity with clinico-radiographically documented idiopathic AVN of femoral head was done after ethics committee approval. DNA was extracted from the blood and PCR analysis was used to study heritable thrombophilic gene mutation (G1691A Factor V Leiden). Enzyme-linked immunosorbent assay (ELISA)-based assays, were utilized to measure antigen levels of protein C, antithrombin III levels and protein S.

RESULTS

Nine cases out of 100 showed deficiency of Protein C (9%) while no control showed deficiency of Protein C (p value: 0.028-significant, Odds ratio: 9.791) Ten cases showed deficiency of Protein S (10%) in study population as compared to one case (2%) in control population (p value: 0.038-significant, Odds ratio: 5.44). ATIII deficiency was more prevalent in control group i.e. 22% compared to 11% in study group. Factor V mutation was present in 3% cases as compared to one (2%) in control group. (p value is 0.393-not significant).

CONCLUSION

Difference in thrombophilic mutations in various populations indicates possible effect of ethnicity on genetic profile in the development of AVN. This risk stratification will enable in near future early diagnosis and possible role of antithrombotics in disease prevention.

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

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

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

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

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

Osteonecrosis in children with acute lymphoblastic leukemia: A report from Children's Cancer Hospital Egypt (CCHE)

BACKGROUND

As survival rates for children with acute lymphoblastic leukemia (ALL) improve, awareness of treatment complications becomes important. Osteonecrosis (ON) is a serious disabling complication in treated ALL patients. The aim of the study was to define the frequency of ON identified by magnetic resonance imaging (MRI) and to study the risk factors for ON.

PATIENTS AND METHODS

The frequency of ON was evaluated retrospectively in 858 patients with ALL who were diagnosed at Children's Cancer Hospital of Egypt from January 2009 to December 2012. Patients were treated with St Jude Total Therapy Study XV.

RESULTS

Of 858 patients evaluated, 665 were eligible for the study and 65 (9.7%) developed ON. The cumulative 5-year incidence of ON was 11.96% (SE, 0.131%). Of 154 patients aged 10 years and older, 40 (26%) developed ON. The mean age of patients with ON was 10.7 years. The prognostic factors with a significant relationship with ON were age 10 years and older (P = 0.0001) and intermediate-/high-risk group (P = 0.0001). However, gender did not have a significant relationship. At the onset of ON, the mean cumulative dexamethasone dose was 796 mg/m² , and the mean total corticosteroid dose, calculated as prednisolone equivalence, was 6,431 mg/m² . Out of 43 patients who developed ON while on corticosteroid therapy, 36 (84%) required dexamethasone dose modification and/or discontinuation.

CONCLUSION

The frequency of ON among the studied patients was 9.7%. Risk factors with a significant association with ON were older age and more intensive corticosteroid therapy.

Association of MTHFR and TNF-α genes polymorphisms with susceptibility to Legg-Calve-Perthes disease in Iranian children: A case-control study

Objective

The aim of this study was to assess the association of MTHFR and TNF-α genes polymorphisms with Legg-Calvé-Perthes' disease (LCPD) risk in the Iranian children.

Methods

A total of 45 children with LCPD and 55 healthy controls were recruited to the study. Genotyping was performed via the RFLP-PCR method and genetic risk was calculated by odds ratio (OR) with its corresponding 95% confidence interval (CI).

Results & conclusion

Our case-control study failed to determine any association of MTHFR (677C > T and 1298A > C) and TNF-α (-308G > A and -238G > A) polymorphisms with LCPD risk. More studies with larger sample size are warranted to validate our findings.

Genetics of pleiotropic effects of dexamethasone

OBJECTIVES

Glucocorticoids such as dexamethasone have pleiotropic effects, including desired antileukemic, anti-inflammatory, or immunosuppressive effects, and undesired metabolic or toxic effects. The most serious adverse effects of dexamethasone among patients with acute lymphoblastic leukemia are osteonecrosis and thrombosis. To identify inherited genomic variation involved in these severe adverse effects, we carried out genome-wide association studies (GWAS) by analyzing 14 pleiotropic glucocorticoid phenotypes in 391 patients with acute lymphoblastic leukemia.

PATIENTS AND METHODS

We used the Projection Onto the Most Interesting Statistical Evidence integrative analysis technique to identify genetic variants associated with pleiotropic dexamethasone phenotypes, stratifying for age, sex, race, and treatment, and compared the results with conventional single-phenotype GWAS. The phenotypes were osteonecrosis, central nervous system toxicity, hyperglycemia, hypokalemia, thrombosis, dexamethasone exposure, BMI, growth trajectory, and levels of cortisol, albumin, and asparaginase antibodies, and changes in cholesterol, triglycerides, and low-density lipoproteins after dexamethasone.

RESULTS

The integrative analysis identified more pleiotropic single nucleotide polymorphism variants (P=1.46×10(-215), and these variants were more likely to be in gene-regulatory regions (P=1.22×10(-6)) than traditional single-phenotype GWAS. The integrative analysis yielded genomic variants (rs2243057 and rs6453253) in F2RL1, a receptor that functions in hemostasis, thrombosis, and inflammation, which were associated with pleiotropic effects, including osteonecrosis and thrombosis, and were in regulatory gene regions.

CONCLUSION

The integrative pleiotropic analysis identified risk variants for osteonecrosis and thrombosis not identified by single-phenotype analysis that may have importance for patients with underlying sensitivity to multiple dexamethasone adverse effects.

Current practice of BHS members in the treatment of osteonecrosis of the femoral head in adults

INTRODUCTION

The management of osteonecrosis (ON) of the femoral head remains controversial. It is unclear the extent to which non-arthroplasty procedures are used and there has been no previous report of the trends in operative management of ON in the UK. Our objective is to report current trends in management of ON of the femoral head amongst specialist hip surgeons in the UK.

METHODS

A single-stage internet-based survey was e-mailed to 352 eligible members of the British Hip Society (BHS). This consisted of 10 question stems including 16 hypothetical clinical scenarios with imaging.

RESULTS

115 active Consultant members of the BHS completed the survey. For symptomatic pre-collapse ON we found core decompression (CD) was the most common operative intervention and for post-collapse ON we found that total hip arthroplasty (THA) was the most common operative intervention. We found no difference in the rate of operative intervention between 24 and 48-year-old patients at any stage of ON but joint preserving procedures were more often selected for the younger patient and arthroplasty for the older patient. Surgeons were more likely to offer arthroplasty to a 48-year-old patient at an earlier stage of disease.

CONCLUSIONS

Our respondents would offer different operative interventions dependent on stage of ON and patient age. Core decompression (CD) and arthroplasty were common but variation in treatment options offered suggests a lack of consensus amongst UK hip surgeons. We suggest that further research such as a prospective RCT is needed to gain consensus on management of this condition.

Role of coagulopathy in glucocorticoid-induced osteonecrosis of the femoral head

The two major theories of glucocorticoid (GC)-induced osteonecrosis of the femoral head (ONFH) are apoptosis and ischaemia. The traditional theory implicates ischaemia as the main aetiological factor because the final common pathway of ONFH is interruption of blood supply to the bone. The most common causes of interruption of blood supply include fat embolism and coagulation disorders. GCs can directly or indirectly lead to coagulation disorders, producing a hypercoagulable state, followed by poor blood flow, ischaemia, and eventually ONFH. This review summarizes the existing knowledge on coagulation disorders in the context of GC-induced ONFH, including hypofibrinolysis and thrombophilia, endothelial cell dysfunction and damage, endothelial cell apoptosis, lipid metabolism, platelet activation, and the effect of anticoagulant treatment.

The use of anticoagulants for prevention and treatment of osteonecrosis of the femoral head: A systematic review

BACKGROUND

Osteonecrosis of the femoral head (ONFH) is a progressive disease, which mainly affects young adults and often necessitates total hip arthroplasty (THA), so early interventions are critical to successfully protect hip joint from THA. In this review, our purpose was to determine the effects of anticoagulants for preventing and treating the primary and secondary ONFH, respectively, before the collapse stage or before the pathology of necrosis.

METHODS

We searched PubMed, Embase, Web of Science databases for relevant studies. Any observational or experimental studies that evaluated anticoagulants and ONFH were our goal of searching the electric databases.

RESULTS

Four studies including a total of 218 hips were identified in this review, 2 of them were prospective studies which performed by 1 group, 1 was a retrospective study, and the last was a prospective comparative study.

CONCLUSIONS

Our findings supported that the anticoagulants could be used for primary ONFH. However, anticoagulants cannot play a protective role on secondary ONFH. Moreover, there were no serious adverse effects reported in the studies after anticoagulants treatment. Nevertheless, our present study with some limitations such as the limited sample size only provided limited quality of evidence; confirmation from further systematic review or meta-analysis with large-scale, well-designed randomized control trials is required.

Case report: primary osteonecrosis associated with thrombophilia-hypofibrinolysis and worsened by testosterone therapy

Background

Familial and acquired thrombophilia are often etiologic for idiopathic hip and jaw osteonecrosis (ON), and testosterone therapy (TT) can interact with thrombophilia, worsening ON.

Case presentation

Case 1: A 62-year-old Caucasian male (previous deep venous thrombosis), on warfarin 1 year for atrial fibrillation (AF), had non-specific right hip-abdominal pain for 2 years. CT scan revealed bilateral femoral head ON without collapse. Coagulation studies revealed Factor V Leiden (FVL) heterozygosity, 4G/4G plasminogen activator inhibitor (PAI) homozygosity, high anti-cardiolipin (ACLA) IgM antibodies, and endothelial nitric oxide (NO) synthase (eNOS) T786C homozygosity (reduced conversion of L-arginine to NO, required for bone health). Apixaban 5 mg twice daily was substituted for warfarin; and L-arginine 9 g/day was started to increase NO. On Apixaban for 8 months, he became asymptomatic. Case 2: A 32-year-old hypogonadal Caucasian male had 10 years of unexplained tooth loss, progressing to primary jaw ON with cavitation 8 months after starting TT gel 50 mg/day. Coagulation studies revealed FVL heterozygosity, PAI 4G/4G homozygosity, and the lupus anticoagulant. TT was discontinued. Jaw pain was sharply reduced within 2 months.

Conclusions

Idiopathic ON, often caused by thrombophilia-hypofibrinolysis, is worsened by TT, and its progression may be slowed or stopped by discontinuation of TT and, thereafter, anticoagulation. Recognition of thrombophilia-hypofibrinolysis before joint collapse facilitates anticoagulation which may stop ON, preserving joints.

Protective effects of molecular hydrogen on steroid-induced osteonecrosis in rabbits via reducing oxidative stress and apoptosis

Background

The objective of this study was to investigate the protective effects of molecular hydrogen, a novel and selective antioxidant, on steroid-induced osteonecrosis (ON) in a rabbit model.

Methods

Sixty rabbits were randomly divided into two groups (model group and hydrogen group). Osteonecrosis was induced according to an established protocol of steroid-induced ON. Rabbits in the hydrogen group were treated with intraperitoneal injections of molecular hydrogen at 10 ml/kg body weight for seven consecutive days. Plasma levels of total cholesterol, triglycerides, soluble thrombomodulin(sTM), glutathione(GSH) and malondialdehyde(MDA) were measured before and after steroid administration. The presence or absence of ON was examined histopathologically. Oxidative injury and vascular injury were assessed in vivo by immunohistochemical staining of 8-hydoxy-2-deoxyguanosine(8-OHdG) and MDA, and ink artery infusion angiography. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assays were performed to measure apoptosis.

Results

The incidence of steroid-induced ON was significantly lower in hydrogen group (28.6%) than that in model group (68.0%). No statistically differences were observed on the levels of total cholesterol and triglycerides. Oxidative injury, vascular injury and apoptosis were attenuated in the hydrogen group compared with those in the model group in vivo.

Conclusions

These results suggested that molecular hydrogen prevents steroid-induced osteonecrosis in rabbits by suppressing oxidative injury, vascular injury and apoptosis.

Atraumatic Femoral Head Necrosis in Adults

BACKGROUND

Atraumatic necrosis of the femoral head is a common cause of hip arthrosis in middle age. In Germany, it affects 5000-7000 patients per year, corresponding to an incidence of 0.01%. Though rarer than primary hip arthrosis, it is still of major clinical and socio-economic significance. Patients with this problem should be diagnosed early and given stage-appropriate treatment.

METHODS

This review is based on pertinent publications that were retrieved by a selective search in the PubMed, Embase, Medline, and Cochrane Library databases using the terms "osteonecrosis," "femoral head necrosis," "diagnosis," "classification," "conservative treatment," "surgical treatment," "joint preservation," "osteotomy," and "arthroplasty," as well as a recent guideline on atraumatic necrosis of the femoral head in adults.

RESULTS

The etiology and pathogenesis of atraumatic femoral head necrosis in adults are not yet fully clear. The main risk factor is prolonged corticosteroid treatment. Nonspecific complaints and an initially normal plain x-ray of the hip can delay the diagnosis. The diagnosis is established by plain x-ray, computerized tomography, magnetic resonance tomography, and scintigraphy. Conservative treatment alone is not considered adequate. The range of surgical treatments includes joint-preserving and (for more severe necrosis) joint-resecting methods.

CONCLUSION

Atraumatic femoral head necrosis in adults is a disease that progresses in stages; depending on its stage, it can either be cured or lead to hip arthrosis. A full cure is possible only in early stages. Current research focuses on the effect of new drugs on the intermediateand long-term outcome.

Bone Marrow Aspirate Concentrate in Combination With Intravenous Iloprost Increases Bone Healing in Patients With Avascular Necrosis of the Femoral Head: A Matched Pair Analysis

With disease progression, avascular necrosis (AVN) of the femoral head may lead to a collapse of the articular surface. The exact pathophysiology of AVN remains unclear, although several conditions are known that can result in spontaneous cell death, leading to a reduction of trabecular bone and the development of AVN. Hip AVN treatment is stage-dependent in which two main stages of the disease can be distinguished: pre-collapse (ARCO 0-II) and post-collapse stage (ARCO III-IV, crescent sign). In the pre-collapse phase, core decompression (CD), with or without the addition of bone marrow (e.g. bone marrow aspirate concentrate, BMAC) or bone graft, is a common treatment alternative. In the post-collapse phase, THA (total hip arthroplasty) must be performed in most of the patients. In addition to surgical treatment, the intravenous application of Iloprost has been shown to have a curative potential and analgesic effect. From October 2009 to October 2014, 49 patients with AVN (stages I-III) were treated with core decompression at our institution. All patients were divided into group A (CD + BMAC) and group B (CD alone). Of these patients, 20 were included in a matched pair analysis. The patients were matched to age, gender, ARCO-stage, Kerboul combined necrotic angle, the cause of AVN, and whether Iloprost-therapy was performed. The Merle d’Aubigné Score and the Kerboul combined necrotic angle in a-p and lateral radiographs were evaluated pre- and postoperatively. The primary endpoint was a total hip arthroplasty. In group A, two patients needed THA while in group B four patients were treated with THA. In group A, the Merle d’Aubigné Score improved from 13.5 (pre-operatively) to 15.3 (postoperatively). In group B there was no difference between the pre- (14.3) and postoperative (14.1) assessment. The mean of the Kerboul angle showed no difference in both groups compared pre- to postoperatively (group A: pre-op 212°, postop 220°, group B: pre-op 213, postop 222°). Regarding radiographic evaluation, the interobserver variability revealed a moderate agreement between two raters regarding the pre-(ICC 0.594) and postoperative analysis (ICC 0.604).This study demonstrates that CD in combination with the application of autologous bone marrow aspirate concentrate into the femoral head seems to be a safe and efficient treatment alternative in the early stages of AVN of the femoral head when compared to CD alone.

Osteonecrosis

Younger patients are affected more often by osteonecrosis than by osteoarthritis, and osteonecrosis has significantly greater long-term morbidity.

Corticosteroids are the most common cause of nontraumatic osteonecrosis.

The femoral head is the most common site of osteonecrosis.

In rare instances, osteonecrosis of the jaw has been associated with bisphosphonate exposure. This phenomenon is more common with repeated intravenous infusions of bisphosphonates.

Case reports of osteonecrosis of the jaw in association with other medications, such as denosumab, have been reported.

The final common pathway in the pathogenesis of osteonecrosis is disruption of blood supply to a segment of bone.

Abnormalities in lipid metabolism, bone homeostasis, regulation of apoptosis, coagulopathies, innate immunity, and oxidative stress may play a role in the pathogenesis of osteonecrosis.

Epigenetics may alter the predisposition to develop osteonecrosis.

MRI is currently the optimal test for early diagnosis and identification of the extent of osteonecrosis.

Nonsurgical treatment of osteonecrosis does not change the natural history of the disease.

Although surgical treatment of femoral head osteonecrosis has many variations, most symptomatic patients eventually require total hip arthroplasty.

Knowledge of risk factors and early detection are crucial to the successful management of osteonecrosis.

Because of the lack of successful treatment options, new modes of management focus on the prevention of osteonecrosis.

Osteonecrosis in children with acute lymphoblastic leukemia

The morbidity and toxicity associated with current intensive treatment protocols for acute lymphoblastic leukemia in childhood become even more important as the vast majority of children can be cured and become long-term survivors. Osteonecrosis is one of the most common therapy-related and debilitating side effects of anti-leukemic treatment and can adversely affect long-term quality of life. Incidence and risk factors vary substantially between study groups and therapeutic regimens. We therefore analyzed 22 clinical trials of childhood acute lymphoblastic leukemia in terms of osteonecrosis incidence and risk factors. Adolescent age is the most significant risk factor, with patients >10 years old at the highest risk. Uncritical modification or even significant reduction of glucocorticoid dosage cannot be recommended at this stage. A novel and innovative approach to reduce osteonecrosis-associated morbidity might be systematic early screening for osteonecrosis by serial magnetic resonance images. However, discriminating patients at risk of functional impairment and debilitating progressive joint disease from asymptomatic patients still remains challenging.

Thrombophilia in Klinefelter Syndrome With Deep Venous Thrombosis, Pulmonary Embolism, and Mesenteric Artery Thrombosis on Testosterone Therapy: A Pilot Study

We compared thrombophilia and hypofibrinolysis in 6 men with Klinefelter syndrome (KS), without previously known familial thrombophilia, who had sustained deep venous thrombosis (DVT)-pulmonary emboli (PE) or mesenteric artery thrombosis on testosterone replacement therapy (TRT). After the diagnosis of KS, TRT had been started in the 6 men at ages 11, 12, 13, 13, 19, and 48 years. After starting TRT, DVT-PE or mesenteric artery thrombosis was developed in 6 months, 1, 11, 11, 12, and 49 years. Of the 6 men, 4 had high (>150%) factor VIII (177%, 192%, 263%, and 293%), 3 had high (>150%) factor XI (165%, 181%, and 193%), 1 was heterozygous for the factor V Leiden mutation, and 1 was heterozygous for the G20210A prothrombin gene mutation. None of the 6 men had a precipitating event before their DVT-PE. We speculate that the previously known increased rate of DVT-PE and other thrombi in KS reflects an interaction between prothrombotic, long-term TRT with previously undiagnosed familial thrombophilia. Thrombophilia screening in men with KS before starting TRT would identify a cohort at increased risk for subsequent DVT-PE, providing an optimally informed estimate of the risk/benefit ratio of TRT.

Treatable high homocysteine alone or in concert with five other thrombophilias in 1014 patients with thrombotic events

In 1014 patients with thrombotic events, we determined how often treatable high serum homocysteine alone, or in concert with five other thrombophilias, was associated with thrombotic events. We studied 1014 outpatients sequentially referred for evaluation of thrombotic events, all having six measures of thrombophilia--three PCR (methylenetetrahydrofolate reductase C677T-A1298C, factor V Leiden G506A, prothrombin G20210A), and three serologic (factors VIII, XI, homocysteine). Of the 1014 patients, 198 (20%) had atherothrombosis, 199 (20%) ocular vascular thrombosis, 211 (21%) osteonecrosis, 180 (18%) pseudotumor cerebri, and 123 (12%) recurrent miscarriage. In 434 of 1014 (43%) patients, all six thrombophilic measures were normal. High homocysteine, present in 126 of 1014 patients (12.4%), was the sole thrombophilia in 50 (5%), accompanied only by methylenetetrahydrofolate reductase homozygosity-compound heterozygosity in 22 (2.2%), and accompanied by other thrombophilias in 54 (5%). Patients were more likely than 110 healthy controls to have high homocysteine (12 vs. 5%; P = 0.02) and high factor VIII (21 vs. 7%; P = 0.0003). On treatment for a median of 18 months with L-methyl folate (5 mg), vitamin B6 (100 mg), and vitamin B12 (2 mg/day), in 74 homocysteinemic patients, median homocysteine fell from 15.6 to 10.0 μmol/l (P < 0.0001), and in 56 (76%), homocysteine fell to normal on treatment. When homocysteinemia was the sole thrombophilia, normalization of homocysteine was accompanied by freedom from new thrombotic events in 38 of 41 patients (93%). In evaluation of 1014 patients with thrombotic events, 126 (12%) had treatable high serum homocysteine, and in 50 (5%), high homocysteine was the sole treatable thrombophilia.

Risk factors for symptomatic osteonecrosis in childhood ALL: A retrospective study of a Slovenian pediatric ALL population between 1970 and 2004

Treatment induced non-traumatic osteonecrosis (ON) has been reported increasingly in children treated for acute lymphoblastic leukemia (ALL). Several risk factors for ON have been identified in childhood cancer patients; however, their diagnostic and prognostic power is limited and the etiology of the disease remains unclear. Therefore, a continuous effort is focused on the identification of additional ON risk factors. We performed a retrospective study of 313 childhood ALL patients to test the association between the ON occurrence in children receiving ALL therapy and common polymorphisms in potential target genes: Thiopurine S-methyltransferase (TPMT; 460G>A, 719A>G), 5,10-methylenetetrahydrofolate reductase (MTHFR; 677C>T, 1298A>C), estrogen receptor alpha 1 (ESR1; XbaI) and collagen type I, α1 (COL1A1; Sp1). In the present cohort, higher age and more recently developed treatment protocols were independent risk factors for ON. In children >14.5 years old, TPMT genotype modulated the risk of ON. Additionally, in children <12.9 years old ESR1 genotypes were also implicated in the pathogenesis of ON. Besides greater age and more recent treatment protocols, genetic factors (polymorphisms in ESR1 and TPMT genes) were suggested to be implicated in the pathogenesis of ON and could be potentially used as genetic prognostic markers for ON.

Associations of Thrombophilia, Hypofibrinolysis, and Retinal Vein Occlusion

We prospectively assessed whether thrombophilia and hypofibrinolysis, amplified by thrombophilic hormone replacement therapy (HRT), were associated with retinal vein occlusion (RVO). We studied 44 cases (18 men, 26 women), ≥ 3 months after RVO, 42 with central RVO, 2 with branch RVO, in the consecutive order of their referral by 2 community-based ophthalmologists. PCR and serologic coagulation assays were compared to 83 and 40 healthy adult normal controls, respectively. The 4G allele frequency of the plasminogen activator inhibitor-1 (PAI-1) gene, associated with hypofibrinolysis, was 56 of 88 (64%) in cases vs 79 of 166 (48%) in controls, X2 = 5.95, p = .015. The PAI-1 gene product, plasminogen activator inhibitor activity (PAI-Fx), was higher in cases than controls (age-race-sex-adjusted mean 12.2 U/mL vs 6.3, p = .013). By stepwise logistic regression, the PAI-1 gene 4G allele was associated with RVO, odds ratio 1.94, 95% CI 1.12-3.34, p = .018. Thrombophilic resistance to activated protein C (RAPC) was present in 6 of 32 (19%) of cases vs 0 of 40 (0%) controls, Fisher’s p [pf] = .006. Thrombophilic high factor VIII (>150%) was present in 3 of 30 (10%) cases vs 0 of 40 (0%) controls, p = .041, pf = .07. Comparing 23 RVO cases ≤ age 55 and controls ≤ age 55 (n = 44 for PCR, n = 40 for serologic measures), RAPC was present in 17% of cases vs 0% controls (pf = .026), high Factor VIII in 17% vs 0% (pf = .026), heterozygosity for the G1691A Factor V Leiden mutation in 13% vs 2% (pf = 0.11), and the 4G allele frequency of the PAI-1 gene 74% vs 39% (p = .0001). PAIFx was higher in cases than controls (age-race-sex adjusted mean 12.7 U/mL vs 6.7, p = .016). The case-control odds ratio for the PAI-1 4G allele was 5.54, 95% CI = 1.86-16.7, p = .002. Of the 26 women, 9 (35%) took HRT; 4 of the 9 had PAI-1 gene 4G4G homozygosity, 2 had thrombophilic high anticardiolipin antibody (IgG), 1 was heterozygous for the G1691A Factor V Leiden mutation, and 2 were heterozygous for the thrombophilic PL A1/A2 mutation of the platelet glycoprotein IIb/IIIa gene. Associations between heritable coagulation disorders and RVO, most marked in cases ≤ age 55, and often amplified in women by thrombophilic HRT, are, speculatively, causal.

Pregnancy Loss, Polycystic Ovary Syndrome, Thrombophilia, Hypofibrinolysis, Enoxaparin, Metformin

Thrombophilia, hypofibrinolysis, and polycystic ovary syndrome (PCOS) are associated with recurrent pregnancy loss (RPL) and spontaneous abortion (SAB) alone and concurrently. The efficacy and safety of combined enoxaparin-metformin was prospectively assessed in women with PCOS with one or more previous SAB, thrombophilia, and/or hypofibrinolysis. Twenty-four white women with PCOS were studied; 23 with previous pregnancies, seven with RPL of unknown etiology (≥ three consecutive pregnancy losses <20 weeks’ gestation), two with two consecutive SABs, 13 with one SAB, and one with one live birth (HELLP syndrome). Prospectively, metformin (1.5 to 2.55 g/day) was administered before and throughout gestation, with concurrent enoxaparin (60 mg/day) throughout gestation. The 24 cases differed from 93 normal white female controls for the factor V Leiden mutation, 17% vs. 2%, Fisher’s p [pf] = .016, and for the 4G4G mutation of the plasminogen activator inhibitor-1 (PAI-1) gene (46% vs. 24%, Chi-square 4.63, p =. 031). The patients also differed from 44 normal white female controls for high levels (> 21.1 U/mL) of the PAI-1 gene product, plasminogen activator inhibitor activity (PAI-Fx) (33% vs. 8%, pf =. 018), and for high factor VIII (>150%) (22% vs. 0%, pf = .037). Of the 24 women, 23 had 65 previous pregnancies without metformin or enoxaparin, with 18 live births, 46 SAB (71%), and one elective abortion. On metforminenoxaparin, the same 23 women had 26 current pregnancies (28 fetuses), with 20 live births, two normal pregnancies 13 weeks or longer, and six SAB (21%), 3.4-fold lower than previous gestations (McNemar’s S = 33.6, p <. 0001). There were no adverse maternal or fetal therapy effects. Enoxaparin-metformin reduces pregnancy loss in women with PCOS with one or more previous SAB, who also have thrombophilia and/or hypofibrinolysis.

Ramifications of Four Concurrent Thrombophilic Mutations and One Hypofibrinolytic Mutation

A kindred was examined in which the 48-year-old white female proband with three deep venous thrombosis-pulmonary emboli events had four thrombophilic and one hypofibrinolytic mutations, and in which her 14-year-old asymptomatic daughter had four thrombophilic mutations. The proband was heterozygous for the G1691A factor V Leiden, G20210A prothrombin, and platelet glycoprotein IIIa PL A1/A2 mutations, had high factor VIII (221%), and was homozygous for the 4G4G plasminogen activator inhibitor-1 gene mutation, with high plasminogen activator inhibitor activity (23.7 U/mL). Her 14-year-old daughter was homozygous for the G1691A factor V Leiden and platelet glycoprotein IIb-IIIa PL A2/A2 mutations, compound heterozygous for the C677T and A1298C methylenetetrahydrofolate reductase (MTHFR) mutations, and heterozygous for the G20210A prothrombin mutation, a combination with an estimated likelihood of 1.6 × 10-7. In 247 white healthy controls, there was no V Leiden homozygosity and no V Leiden-prothrombin gene compound heterozygosity. Heterozygosity for the V Leiden and prothrombin gene mutations was 3.2% and 4.1%, respectively. Homozygosity for the platelet glycoprotein IIb-IIIa PL A2A2, PAI-1 gene 4G4G, and C677T MTHFR mutations was 3.2%, 22.7%, and 12%, respectively. The proband will receive anticoagulation therapy for life. Beyond aspirin, avoidance of exogenous estrogens, and enoxaparin prophylaxis during pregnancy, it is not known whether the proband’s daughter should have lifelong anticoagulation therapy, or only after her first thrombotic event.

Idiopathic Intracranial Hypertension: Associations with Thrombophilia and Hypofibrinolysis in Men

The existence of an association between idiopathic intracranial hypertension (IIH) and coagulation disorders in men was assessed prospectively. Microthrombi, associated with thrombophilia-hypofibrinolysis, occlude arachnoid sinus villi, thus reducing resorption of cerebrospinal fluid, leading to IIH. Ten consecutively referred men with IIH, nine whites, one African American, median age 36 years, were 2 to 1 matched by age and race by healthy male controls. Polymerase chain reaction assays were done for four thrombophilic and one hypofibrinolytic gene mutations: G1691A factor V Leiden, G20210A prothrombin, C677T MTHFR, platelet glycoprotein IIb/IIIa (PL A1/A2), and 4G/5G polymorphism of the plasminogen activator inhibitor (PAI-1) gene promoter. Coagulation measures in plasma included dilute Russel’s viper venom time (dRVVT), activated partial thromboplastin time (aPTT), the lupus anticoagulant, factor VIII, factor XI, plasminogen activator inhibitor activity (PAI-Fx), protein C antigenic, protein S total (antigenic), protein S free (antigenic), antithrombin III (functional), and resistance to activated protein C (RAPC). Tests performed on serum included anticardiolipin antibodies, homocysteine, and Lp(a). The body mass index was 40 kg/m2 or greater (extremely obese) in two men, 30 to 40 kg/m2(obese) in three, and was 25 to 30 kg/m2 in five (overweight). Cases differed from controls for inherited 4G4G homozygosity of the PAI-1 gene, four of 10 (40%) vs. one of 20 (5%), Fisher’s p [pf]= .031, and for high levels (>21.1 U/mL) of the hypofibrinolytic PAI-1 gene product, PAI-Fx, 5 of 10 (50%) vs. one of 18 (6%), pf = .013. Thrombophilic factor VIII was high (≥ 150%) in three of 10 (30%) cases vs. zero of 16 (0%) controls, pf=. 046. The thrombophilic lupus anticoagulant was present in two of 10 (20%) cases vs. zero of 32 (0%) controls, pf = .052. Heritable hypofibrinolysis and heritable and acquired thrombophilia appear, speculatively, to be treatable etiologies of IIH in men. Understanding contributions of hypofibrinolysis and thrombophilia to the development of IIH should facilitate development of novel new approaches to treat this often-disabling neurologic disorder.

Hospitalization for pulmonary embolism associated with antecedent testosterone or estrogen therapy in patients found to have familial and acquired thrombophilia

BACKGROUND

In patients hospitalized over a 4 year period for pulmonary embolism (PE), we assessed relationships of testosterone (TT) and estrogen therapy (ET) anteceding PE in patients found to have familial-acquired thrombophilia.

METHODS

From 2011 through 2014, 347 patients were hospitalized in Cincinnati Mercy Hospitals with PE. Retrospective chart review was used to identify patients receiving TT or ET before PE; coagulation studies were done prospectively if necessary.

RESULTS

Preceding hospitalization for PE, 8 of 154 men (5 %) used TT, and 24 of 193 women (12 %) used ET. The median number of months from the initiation of TT or ET to development of PE was 7 months in men and 18 months in women. Of the 6 men having coagulation measures, all had ≥ 1 thrombophilia, and of the 18 women having measures of coagulation, 16 had ≥ 1 thrombophilia. The sensitivity of a previous history of thrombosis to predict PE was low, 25 % (2/8 men), 4 % (1/24 women).

CONCLUSIONS

Of 154 men hospitalized for PE, 8 (5 %) used TT, and of 193 women, 24 (12 %) used ET. Our data suggests that PE is an important complication of TT in men and ET in women, in part reflecting an interaction between familial and acquired thrombophilia and exogenous hormone use.

Testosterone Therapy Can Interact With Thrombophilia, Leading to Osteonecrosis

Although this effect is not widely recognized, testosterone therapy can interact with thrombophilia, causing osteonecrosis. In 12 men and 4 women who had idiopathic osteonecrosis a median of 6 months after the onset of testosterone therapy, the authors examined the interaction between testosterone therapy and previously undiagnosed thrombophilia. The authors hypothesized that patients who had osteonecrosis after starting testosterone therapy were more likely than 110 normal control subjects or 48 patients who had osteonecrosis and were not receiving testosterone therapy to have thrombophilia. Measures of thrombophilia included Factor V Leiden, prothrombin, PAI-1 gene mutations, Factor VIII, Factor XI, anticardiolipin antibody immunoglobulin G or immunoglobulin M, and homocysteine values. In 10 cases, osteonecrosis occurred 6 months or less after the onset of testosterone therapy, and in all 16 cases, it occurred after a median of 6 months of testosterone therapy. Of the 16 cases, 5 (31%) were Factor V Leiden heterozygotes vs 2 of 109 (2%) healthy control subjects (P=.0003) and 4 of 48 patients who had osteonecrosis and were not receiving testosterone therapy (P=.04). Of the 16 cases, 4 (25%) had high (>150%) Factor VIII levels vs 7 of 103 (7%) healthy control subjects (P=.04), and 3 (19%) had high (>150%) Factor XI levels vs 3 of 101 (3%) healthy control subjects (P=.03). Of the 16 patients with osteonecrosis, 14 (88%) had at least 1 abnormal procoagulant value (of the 8 measured) vs 47 of 110 (43%) healthy control subjects (P=.0009). Of the 5 men whose serum estradiol level was measured while they were receiving testosterone therapy, this level was high (≥42.6 pg/mL) in 4. When testosterone therapy is given to patients with thrombophilia, they are at increased risk for osteonecrosis.

The simultaneous occurrence of both hypercoagulability and hypofibrinolysis in blood and serum during systemic inflammation, and the roles of iron and fibrin(ogen)

Although the two phenomena are usually studied separately, we summarise a considerable body of literature to the effect that a great many diseases involve (or are accompanied by) both an increased tendency for blood to clot (hypercoagulability) and the resistance of the clots so formed (hypofibrinolysis) to the typical, 'healthy' or physiological lysis. We concentrate here on the terminal stages of fibrin formation from fibrinogen, as catalysed by thrombin. Hypercoagulability goes hand in hand with inflammation, and is strongly influenced by the fibrinogen concentration (and vice versa); this can be mediated via interleukin-6. Poorly liganded iron is a significant feature of inflammatory diseases, and hypofibrinolysis may change as a result of changes in the structure and morphology of the clot, which may be mimicked in vitro, and may be caused in vivo, by the presence of unliganded iron interacting with fibrin(ogen) during clot formation. Many of these phenomena are probably caused by electrostatic changes in the iron-fibrinogen system, though hydroxyl radical (OH˙) formation can also contribute under both acute and (more especially) chronic conditions. Many substances are known to affect the nature of fibrin polymerised from fibrinogen, such that this might be seen as a kind of bellwether for human or plasma health. Overall, our analysis demonstrates the commonalities underpinning a variety of pathologies as seen in both hypercoagulability and hypofibrinolysis, and offers opportunities for both diagnostics and therapies.

Genetics of glucocorticoid-associated osteonecrosis in children with acute lymphoblastic leukemia

Glucocorticoids are important therapy for acute lymphoblastic leukemia (ALL) and their major adverse effect is osteonecrosis. Our goal was to identify genetic and nongenetic risk factors for osteonecrosis. We performed a genome-wide association study of single nucleotide polymorphisms (SNPs) in a discovery cohort comprising 2285 children with ALL, treated on the Children's Oncology Group AALL0232 protocol (NCT00075725), adjusting for covariates. The minor allele at SNP rs10989692 (near the glutamate receptor GRIN3A locus) was associated with osteonecrosis (hazard ratio = 2.03; P = 3.59 × 10(-7)). The association was supported by 2 replication cohorts, including 361 children with ALL on St. Jude's Total XV protocol (NCT00137111) and 309 non-ALL patients from Vanderbilt University's BioVU repository treated with glucocorticoids (odds ratio [OR] = 1.87 and 2.26; P = .063 and .0074, respectively). In a meta-analysis, rs10989692 was also highest ranked (P = 2.68 × 10(-8)), and the glutamate pathway was the top ranked pathway (P = 9.8 × 10(-4)). Osteonecrosis-associated glutamate receptor variants were also associated with other vascular phenotypes including cerebral ischemia (OR = 1.64; P = 2.5 × 10(-3)), and arterial embolism and thrombosis (OR = 1.88; P = 4.2 × 10(-3)). In conclusion, osteonecrosis was associated with inherited variations near glutamate receptor genes. Further understanding this association may allow interventions to decrease osteonecrosis. These trials are registered at www.clinicaltrials.gov as #NCT00075725 and #NCT00137111.

Incidence, risk factors, and treatment outcome of symptomatic osteonecrosis in Taiwanese children with acute lymphoblastic leukemia: a retrospective cohort study of 245 patients in a single institution

Osteonecrosis (ON) is a potentially disabling complication encountered in children who receive chemotherapy for acute lymphoblastic leukemia (ALL). Considering the possible effect of ethnic difference on the clinical features of symptomatic ON in pediatric ALL, we retrospectively evaluated 245 children with ALL who were treated at Chang Gung Memorial Hospital, Linkou, between 2002 and 2011. Six (2.4 %) patients developed symptomatic ON in a total of 17 sites during the follow-up period. Diagnosis of ON was confirmed by X-ray in seven, magnetic resonance imaging in two, and bone scan in three patients. The estimated cumulative incidence of symptomatic ON in newly diagnosed ALL was 3.4 % at 8 years. Four patients received ON-directed surgical interventions, including total hip replacement in three and arthroplasty in one. The incidence of ON was significantly higher among girls (P = 0.03), patients >10 years old (P = 2.2 × 10(-4)), and patients who had received more intensive chemotherapy regimen (P = 0.02). These results indicate that the incidence and risk factors in our institute were similar to those observed in Western countries. Future studies surveying the impact on the quality of life of childhood ALL survivors in Taiwan are warranted.

Long term anticoagulation (4-16 years) stops progression of idiopathic hip osteonecrosis associated with familial thrombophilia

In 6 patients with familial thrombophilia (5 Factor V (FV) Leiden heterozygotes, 1 with resistance to activated protein C (RAPC)), we prospectively assessed whether continuous longterm (4–16 years) anticoagulation would prevent progression of idiopathic osteonecrosis (ON), ameliorate pain, and facilitate functional recovery. Four men and 2 women (9 hips, 8 Ficat stage II, 1 stage I) were anticoagulated with enoxaparin (60 mg/day) for 3 months and subsequently with Coumadin, Xarelto, or Pradaxa, warranted by ≥2 prior thrombotic events. Anticoagulation was continued for 4, 4, 9, 13, 13, and 16 years, with serial clinical and X-ray follow-up. On 4–16-years anticoagulation, 9 hips in the 6 patients (8 originally Ficat II, 1 Ficat I) remained unchanged, contrasted to untreated ON Ficat stage II, where 50%–80% of hips progress to collapse (Ficat stages III-IV) within 2 years after diagnosis. Within 3, 3, 3, 9, and 16 months after starting anticoagulation, 5 patients became pain-free and remained asymptomatic throughout follow-up; the 6th patient required Percocet for pain. There were no significant bleeding episodes. Long term (4–16 years) anticoagulation initiated in Ficat stages I-II of idiopathic hip ON in patients with FV-RAPC changes the natural history of ON, stopping progression, resolving pain, and restoring function.

Genetic association between methylenetetrahydrofolate reductase gene polymorphism and risk of osteonecrosis of the femoral head

BACKGROUND

Methylenetetrahydrofolate reductase (MTHFR) SNP rs1801133 has been frequently investigated in recent years. Relevant candidate gene association studies with this SNP and osteonecrosis of the femoral head (ONFH) reported conflicting results. Meta-analysis provides a method to combine these data and to determine the association in a larger sample size.

METHOD

We conducted a systematic search to identify possible studies. Four pooled ORs (odds ratios, T versus C, TT versus CC, TT/CT versus CC, and TT versus CT/CC), along with 95% confidence interval (CI), were calculated to evaluate the association between SNP rs1801133 and ONFH susceptibility. Both fixed effects model and random effects model were used.

FINDINGS

We eventually included twelve studies in this analysis, with results showing no overall association between ONFH susceptibility and SNP rs1801133 (T versus C: OR=1.15, 95% CI=0.97-1.38; TT versus CC: OR=1.15, 95% CI=0.91-1.46; TT/CT versus CC: OR=1.09, 95% CI=0.95-1.25; and TT versus

CT/CC

OR=1.16, 95% CI=0.93-1.45). When stratified based on ethnicity, the results were still not significant.

CONCLUSION

Our findings are generally supportive of no association between MTHFR SNP rs1801133 and the etiology of ONFH.

Management of femoral head osteonecrosis: Current concepts

Osteonecrosis of femoral head (ONFH) is a disabling condition of young individuals with ill-defined etiology and pathogenesis. Remains untreated, about 70-80% of the patients progress to secondary hip arthritis. Both operative and nonoperative treatments have been described with variable success rate. Early diagnosis and treatment is the key for success in preserving the hip joint. Once femoral head collapses (>2 mm) or if there is secondary degeneration, hip conservation procedures become ineffective and arthroplasty remains the only better option. We reviewed 157 studies that evaluate different treatment modalities of ONFH and then a final consensus on treatment was made.

Medical treatment of osteonecrosis of the knee associated with thrombophilia-hypofibrinolysis

In 6 patients with stage II knee osteonecrosis, all 6 with thrombophilia and 4 with concurrent hypofibrinolysis, the authors prospectively determined whether anticoagulation with enoxaparin could prevent collapse and progression to osteoarthritis, ameliorate pain, and restore function. The 6 patients were treated with enoxaparin (40 to 60 mg/d for 3 or more months) as mandated by a US Food and Drug Administration-approved protocol. In post-enoxaparin prospective follow-up, patients were reassessed clinically every 4 to 6 months, and radiographs were obtained every year. The 6 patients followed up at 15.1, 7.5, 3.9, 2.25, 2, and 1 year, respectively. None progressed to joint collapse or severe osteoarthritis. Four became and remained asymptomatic at 2-, 3.9-, 7.5-, and 15.1-year follow-up, respectively. A fifth patient did not progress to collapse or severe osteoarthritis but had residual pain at 2.25-year follow-up. The sixth patient had no symptomatic benefit on enoxaparin but improved on rivaroxaban at 1-year follow-up. Two patients had recurrences of knee pain 1 and 4 years after their initial treatment with enoxaparin. One resolved after a second course of enoxaparin, and the other, with a second recurrence 1 year after the second course, resolved after a third course. Pretreatment, all 6 patients required canes, crutches, or wheelchairs, but after enoxaparin, no patient required them, and walking was unrestricted. Thrombophilia-hypofibrinolysis contributes to the pathogenesis of knee osteonecrosis. Thrombophilic-hypofibrinolytic patients with stage II knee osteonecrosis treated with enoxaparin have had no collapse or progression to severe osteoarthritis, and most have had resolution of pain and restoration of full function. This represents a major improvement compared with the natural history of untreated spontaneous knee osteonecrosis.

Relationship between the Apolipoprotein AI, B gene polymorphism and the risk of non-traumatic osteonecrosis

BACKGROUND

Previous studies suggested that Apolipoprotein AI (ApoAI) and apolipoprotein B (ApoB) gene polymorphisms may result in lipid metabolism disorders. Genetic polymorphisms in these genes may be associated with the occurrence of osteonecrosis.

METHODS

We designed a case-control study including 429 patients of osteonecrosis and 368 age- and sex-matched control subjects. Polymerase chain reaction was used to amplify the DNA fragments in promoter -75 G > A of ApoAI gene and EcoR I, Xba I and 3'-VNTR of ApoB gene in osteonecrosis patients and healthy controls. We utilized polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method to genotype these four single nucleotide polymorphisms (SNPs).

RESULTS

For -75 G > A polymorphism of ApoAI, AA genotype frequency (0.501) was significantly higher in patients with osteonecrosis than that in control (0.462) subjects (P <0.001), GA genotype frequency (0.170) was significantly lower than that in the control (0.310) group (P <0.0001). In osteonecrosis patients, the odds ratio (OR) of A allele was 3.932 (95% CI: 3.0847 ~ 5.0123), which suggested that subjects carrying A allele of promoter region -75 G > A of ApoAI gene had higher susceptibility to osteonecrosis than G allele carriers. The genotype and allele frequency distributions showed no significant difference in EcoR I, Xba Iand 3'-VNTR loci of ApoB gene between the osteonecrosis group and control group.

CONCLUSION

Our study suggested that ApoAI gene -75G > A polymorphism may be associated with susceptibility to osteonecrosis in Chinese population. However, our results need further investigation with large sample size and various populations.

Single nucleotide polymorphisms other than factor V Leiden are associated with coagulopathy and osteonecrosis of the femoral head in Chinese patients

Single nucleotide polymorphisms (SNPs) of factor V Leiden have been associated with osteonecrosis of the femoral head (ONFH) in Caucasians but remains controversial in Asians. We used an SNP microarray to screen 55 loci of factor V gene in patients with ONFH of Chinese. Significantly different candidate SNPs at 14 loci were analyzed in 146 patients and 116 healthy controls using MALDI-TOF (matrix-assisted laser desorption/ionization time-of-flight) mass spectrometry and gene sequencing. The factor V Leiden (rs6025) was not found in all participants. Six SNP loci (rs9332595, rs6020, rs9332647, rs3766110, rs10919186, and rs12040141) were confirmed with significant differences in patients but not in controls. The rs6020 G-to-A polymorphism was found in 88.9% of the patients. In addition, a high percentage (87.6%) of the patients had an abnormal coagulation profile that included hyperfibrinogen, elevated fibrinogen degradation products, elevated D-dimer, abnormal protein S, abnormal protein C, or a decrease in anti-thrombin III. Patients with the rs6020 G-to-A polymorphism (mutation) had a higher risk (odds ratio: 4.62; 95% confidence interval: 1.44-14.8) of having coagulation abnormalities than did those without the mutation (wild-type) (χ(2) p  =  0.006). Our findings suggested that the rs6020 polymorphism might be the genetic trait that accounts for the higher prevalence of ONFH in the Chinese population than in Westerners. Exposure to risk factors such as alcohol and steroids in patients with the rs6020 polymorphism causes coagulation abnormalities and, subsequently, thromboembolisms in the femoral head.