Impact of oral corticosteroid use for idiopathic osteonecrosis of the femoral head: a nationwide multicenter case-control study in Japan

Acetabular coverage exerts minimal influence on femoral head collapse and the necessity for surgical intervention in patients with osteonecrosis of femoral head

PURPOSE

The acetabular coverage in osteonecrosis of the femoral head (ONFH) affects the need for surgical intervention, and the collapse of the femoral head remains unclear. This study aimed to evaluate the relation between the acetabular coverage and the need for surgical treatment and femoral head collapse.

METHODS

The study included 158 patients with 252 hips with glucocorticoid administration and idiopathic ONHF without osteoarthritis changes. The mean age at the first visit was 45.2 years, and the mean follow-up period was 92.2 months. All ONFH hips were subsequently divided into two groups: those needing surgical intervention and those without surgery. Additionally, it divided 167 initially non-collapsed hips into those that either later collapsed or not. Radiographic parameters with the centre-edge angle, acetabular roof obliquity, sharp angle, and necrotic location, following the guidelines of the Japanese Investigation Committee, were evaluated.

RESULTS

There were no significant differences in radiographic parameters between the 106 hips that underwent surgery and the 146 hips without surgery. Among the 167 hips without initial collapse, 91 eventually collapsed while 76 did not; their radiographic findings have no significant differences. The necrotic locations were significantly larger in hips requiring surgical intervention or femoral head collapse. Furthermore, 21.8% (55 out of 252 hips) had acetabular dysplasia, which did not significantly correlate with the necessity for surgical treatment or the incidence of femoral head collapse.

CONCLUSIONS

Acetabular coverage has little effect on the necessity for surgical treatment and femoral head collapse in ONFH patients over a long-term follow-up.

Time elapsed from definitive diagnosis to surgery for osteonecrosis of the femoral head: a nationwide observational study in Japan

OBJECTIVES

This study documents the time elapsed from the diagnosis of osteonecrosis of the femoral head (ONFH) to surgery, exploring the factors that influence ONFH severity.

DESIGN

Retrospective observational study of a nationwide database.

SETTING

The Kaplan-Meier method with log-rank tests was applied to examine the period from definitive diagnosis of ONFH to surgery using any surgery as the end point. For bilateral cases, the date of the first surgery was the endpoint.

PARTICIPANTS

This study included 2074 ONFH cases registered in 34 university hospitals and highly specialised hospitals of the multicentre sentinel monitoring system of the Japanese Investigation Committee between 1997 and 2018.

MAIN OUTCOME MEASURE

The primary outcome was the time from diagnosis to surgery. The secondary outcome was the proportion of subjects remaining without surgery at 3, 6 and 9 months, and at 1, 2 and 5 years after diagnosis.

RESULTS

The median time to surgery was 9 months (IQR 4-22 months) after diagnosis of ONFH. The time to surgery was significantly shorter in the alcohol alone group and the combined corticosteroid and alcohol group than in the corticosteroid alone group (p=0.018 and p<0.001, respectively), in early stage ONFH with no or mild joint destruction (stages II and III, p<0.001), and with joint preserving surgery (p<0.001). The proportion without surgery was 75.8% at 3 months, 59.6% at 6 months, 48.2% at 9 months, 40.5% at 1 year, 22.2% at 2 years and 8.3% at 5 years.

CONCLUSION

ONFH has been considered to be an intractable disease that often requires surgical treatment, but the fact that surgery was performed in more than half of the patients within 9 months from diagnosis suggests severe disease with a significant clinical impact.

TRIAL REGISTRATION NUMBER

Chiba University ID1049.

No evidence of genetic causality between diabetes and osteonecrosis: a bidirectional two-sample Mendelian randomization analysis

OBJECTIVE

This study aimed to examine whether diabetes mellitus is causally associated with osteonecrosis.

METHOD

Using publicly accessible genome-wide association study statistics, a bidirectional two-sample Mendelian randomization analysis was carried out. In order to determine whether diabetes has a causal effect on osteonecrosis and whether osteonecrosis has a causal effect on diabetes, we extracted six date on diabetes in Europeans from IEU OpenGWAS and GWAS Catalogue and osteonecrosis in Europeans from FinnGen. We then evaluated the data using inverse variance weighting, MR-Egger regression, weighted median, weighted mode, and simple mode. The results' stability and dependability were then evaluated using sensitivity analysis and heterogeneity analysis. Finally, meta-analysis is used to further confirm if there is a relationship between diabetes and osteonecrosis.

RESULTS

When diabetes was used as an exposure factor, MR-Egger regression showed that directional fold product was unlikely to bias the results. Cochran's Q test showed only minor heterogeneity in a few data sets. Multidirectional tests Egger-intercept, MR-PRESSO and funnel plots for most data did not show multidirectional and asymmetry at the gene level. Most of the IVW results showed no causal relationship between diabetes mellitus and osteonecrosis. The results of meta-analysis of IVW methods further confirmed the absence of a causal relationship. Inverse MR analysis also showed no causal relationship between osteonecrosis and diabetes.

CONCLUSION

Results of bidirectional MR analysis show no evidence of causal relationship between diabetes and osteonecrosis.

The potential effect of BMSCs with miR-27a in improving steroid-induced osteonecrosis of the femoral head

Steroid induced osteonecrosis of the femoral head (ONFH) frequently leads to femoral head collapse and subsequent hip arthritis. This study aimed to investigate the potential therapeutic mechanism of miR-27a on steroid-induced ONFH. Levels of IL-6, TNF-α, miR-27a, Runx2, PPAR-γ and ApoA5 were first examined in bone marrow tissues from steroid-induced ONFH and controls. Subsequently, we overexpressed or knocked down miR-27a in bone marrow mesenchymal stem cells (BMSCs) and detected cell proliferation, osteogenic differentiation, adipogenic differentiation. In addition, miR-27a mimics and BMSCs were injected into the established steroid-induced ONFH rats, and the osteoprotective effects of both were evaluated. Dual luciferase reporter was used to test the targeting effect of miR-27a-3p and PPARG. miR-27a and Runx2 were lowly expressed in steroid-induced ONFH, PPAR-γ and ApoA5 were highly expressed. Overexpression of miR-27a in BMSCs promoted cell proliferation and osteogenic differentiation, inhibited adipogenic differentiation. Furthermore, increasing miR-27a and BMSCs obviously reduced bone loss in steroid induced ONFH rats. The expressions of Runx2 in BMSCs and steroid-induced ONFH rats was significantly up-regulated, while IL-6, TNF-α, PPAR-γ and ApoA5 were down-regulated with miR-27a overexpression. Additionally, PPARG was the target of miR-27a-3p. The results of the present study reveal a role for miR-27a in promoting osteogenesis and may have a synergistic effect with BMSCs.

Corticosteroid-associated osteonecrosis of the femoral head after orthotopic liver transplantation and the outcomes of subsequent total hip arthroplasty

BACKGROUND

Corticosteroids are essential for immunosuppression after orthotopic liver transplantation (OLT), but also have many side effects. Osteonecrosis of the femoral head (ONFH) is one of the most serious complications requiring prostheses. However, few studies have investigated ONFH after OLT. The purpose of this study is to survey the incidence of corticosteroid-induced ONFH after OLT and the outcomes of total hip arthroplasty (THA).

METHODS

Between January 2001 and December 2010, a series of 926 patients underwent OLT at our Hospital. A retrospective analysis was performed on a total of 738 patients who survived at least 2 years after OLT. The incidence of symptomatic ONFH, the interval from OLT to the initial diagnosis of ONFH, and the cumulative dose of corticosteroids were analyzed. The side effects related to OLT, such as other osteonecrosis lesions, osteoporotic fractures, and infection, were monitored. For patients who underwent THA, radiological findings and Japanese Orthopaedic Association (JOA) scores were evaluated.

RESULTS

ONFH occurred in 10 patients (13 hips) (6 men [7 hips], 4 women [6 hips]), with an incidence of 1.36%. The average age at OLT was 51.4 years (range, 31-61 years). The average interval from OLT to ONFH was 86.7 months (range, 22-155 months). The average cumulative dose of corticosteroids was 7274 mg (range, 1342-29,514 mg). Twenty patients suffered from side effects related to OLT. Seven patients (8 hips) underwent THA. No adverse events including infection arose during the perioperative process. One hip dislocated, and one femoral stem displayed a radiolucent line. The average JOA score improved from 45.4 (range, 25-76) preoperatively to 86.9 (range, 73-99) at final follow-up. No patients required revision surgery.

CONCLUSIONS

The incidence of symptomatic ONFH after OLT was 1.36%. Once the graft function becomes stable, THA can be a safe and effective treatment option for patients with ONFH after OLT.

Geographic distribution of the incidence of osteonecrosis of the femoral head in Japan and its relation to smoking prevalence

OBJECTIVES

Alcohol intake and smoking are modifiable lifestyle-related risk factors for osteonecrosis of the femoral head (ONFH). We investigated geographic differences in ONFH incidence in Japan and the correlation with alcohol intake and smoking to develop prevention strategies for ONFH in Japan.

METHODS

This ecological study was conducted in Japan primarily using the following data sources: nationwide epidemiological survey and national survey. We estimated the annual ONFH incidence and the prevalence of alcohol drinking and smoking in each prefecture. Prefectural incidence and prevalence were calculated by sex and age-standardization.

RESULTS

The mean annual ONFH incidence per 100,000 population was 3.08 in men and 1.63 in women, respectively. There was no significant correlation between ONFH incidence and the prevalence of any levels of alcohol intake, while smoking ≥20 cigarettes/day showed a significant and moderate correlation in men (r = 0.47, p = .01). This correlation remained significant after adjustment for the prevalence of any levels of alcohol intake (standardized partial regression coefficient = 0.47-0.49, p = .009-.01).

CONCLUSION

ONFH incidence is geographically variable in Japan, and this may be partly explained by the distribution of smoking prevalence. Smoking cessation may contribute to an effective decline in the overall ONFH incidence in Japan.

Cotransplantation of mesenchymal stem cells and endothelial progenitor cells for treating steroid-induced osteonecrosis of the femoral head

Steroid-induced osteonecrosis of the femoral head (ONFH) is characterized by decreased osteogenesis, angiogenesis, and increased adipogenesis. While bone tissue engineering has been widely investigated to treat ONFH, its therapeutic effects remain unsatisfactory. Therefore, further studies are required to determine optimal osteogenesis, angiogenesis and adipogenesis in the necrotic area of the femoral head. In our study, we developed a carboxymethyl chitosan/alginate/bone marrow mesenchymal stem cell/endothelial progenitor cell (CMC/ALG/BMSC/EPC) composite implant, and evaluated its ability to repair steroid-induced ONFH. Our in vitro studies showed that BMSC and EPC coculture displayed enhanced osteogenic and angiogenic differentiation. When compared with single BMSC cultures, adipogenic differentiation in coculture systems was reduced. We also fabricated a three-dimensional (3D) CMC/ALG scaffold for loading cells, using a lyophilization approach, and confirmed its good cell compatibility characteristics, that is, high porosity, low cytotoxicity and favorable cell adhesion. 3D coculture of BMSCs and EPCs also promoted secretion of osteogenic and angiogenic factors. Then, we established an rabbit model of steroid-induced ONFH. The CMC/ALG/BMSC/EPC composite implant was transplanted into the bone tunnel of the rabbit femoral head after core decompression (CD) surgery. Twelve weeks later, radiographical and histological analyses revealed CMC/ALG/BMSC/EPC composite implants had facilitated the repair of steroid-induced ONFH, by promoting osteogenesis and angiogenesis, and reducing adipogenesis when compared with CD, CMC/ALG, CMC/ALG/BMSC and CMC/ALG/EPC groups. Thus, our data show that cotransplantation of BMSCs and EPCs in 3D scaffolds is beneficial in treating steroid-induced ONFH.

Retrospective Study on Implantation of Autologous-Cultured Osteoblasts for the Treatment of Patients with Avascular Necrosis of the Femoral Head

Purpose

Osteonecrosis of the femoral head is a progressive and debilitating disease that causes pain, osteoarthritis and hip joint collapse, eventually necessitating hip replacement. This study evaluated the long-term outcomes of autologous adult live-cultured osteoblasts (AALCO) implantation in patients with osteonecrosis of femoral head.

Patients and Methods

In this retrospective multicenter study, we collated and analyzed data of patients ≥12 years of age who underwent AALCO (OSSGROW^®) between 2010 and 2015 for the treatment of osteonecrosis of the femoral head.

Results

Data from 64 patients (101 hip joints) were assessed in this study. The mean ±SD duration of disease since diagnosis of osteonecrosis was 7.4±1.6 years. The mean follow-up duration was 6.3±1.4 years. The mean VAS score (n=98 hips) reduced significantly from 58.8 ± 13.8 to 32.2 ± 32.1 post-operatively (mean difference: −26.5±35.2, p=0.001) and Harris hip score (n=97 hips) also significantly improved from 47.1±12.3 to 63.7±27.7 post-operatively (mean difference:16.7±28.7, p=0.0001). Following the AALCO treatment, 29 hips in 13 patients (28.7%) underwent total hip replacement (THA), indicating that AALCO treatment could delay THA for 71.3% of hips. A total of 39.1% of hips diagnosed in early stage versus 60.8% in the late stage of osteonecrosis required THA. Overall, 60.4% of hips improved, 2% remained stable, and 37.6% progressed following the AALCO implantation. The condition of disease was found to have improved in 71.1% of patients in early stage (Grades I and II) versus 58% in the late stage (Grades III and IV) of osteonecrosis.

Conclusion

Patients with osteonecrosis who received implantation of autologous-cultured osteoblasts using AALCO showed improvement in joint function and decrease in pain. Treatment with AALCO halted progression of osteonecrosis, preserved the natural hip, and eliminated the need for hip replacement surgeries in 7 out of 10 patients.

Japanese Orthopaedic Association 2019 Guidelines for osteonecrosis of the femoral head

PURPOSE

The Clinical Practice Guidelines for Osteonecrosis of the Femoral Head (ONFH) 2019 Edition, written by the working group for ONFH guidelines of the Japanese Investigation Committee (JIC) for ONFH under the auspices of the Japanese Ministry of Health, Labour, and Welfare and endorsed by the Japanese Orthopaedic Association, were published in Japanese in October 2019. The objective of this guideline is to provide a support tool for decision-making between doctors and patients.

METHODS

Procedures for developing this guideline were based on the Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014, which proposed an appropriate method for preparing clinical guidelines in Japan.

RESULTS

This clinical practice guideline consists of 7 chapters: epidemiology; pathology; diagnosis; conservative therapy; surgical treatment: bone transplantation/cell therapy; surgical treatment: osteotomy; and surgical treatment: hip replacement. Twelve background questions and 13 clinical questions were determined to define the basic features of the disease and to be addressed when deciding treatment in daily practice, respectively.

CONCLUSIONS

The clinical practice guidelines for the ONFH 2019 edition will be useful for physicians, investigators, and medical staff in clinical practice, as well as for patients, during the decision-making process when defining how to treat ONFH.

Simultaneous Bilateral Avascular Necrosis of the Femoral Heads Associated With Cocaine Use

We present a case of a 38-year-old female patient, presenting with debilitating simultaneous bilateral avascular necrosis of the femoral head (AVNFH) 10 years after cocaine detoxification, making her wheelchair-bound for six months. This case is reported for the rarity of association of cocaine with AVNFH, and for the unique fact of the simultaneous bilateral condition occurring a long time after cocaine ingestion in the absence of other important risk factors.

This report postulates cocaine as a possible cause of bilateral AVNFH, which can increase the index of suspicion of this pathology, allowing early diagnosis and better outcomes.

Avascular necrosis less frequently found in systemic lupus erythematosus patients with the use of alternate day corticosteroid

Background/aim

Avascular necrosis (AVN) is the death of bone due to compromise of blood flow. The etiology of AVN is multifactorial; corticosteroid usage is the second most significant factor after trauma, and systemic lupus erythematosus (SLE) is the most common underlying disease. The objective of this study was to assess the factors of AVN in SLE patients.

Materials and methods

The study included 127 patients with SLE who fulfilled 1997 American College of Rheumatology (ACR) revised criteria. Demographic data, age at SLE diagnosis, disease duration, disease activity, body mass index, clinical findings, antiphospholipid syndrome, steroid usage, dose and duration, comorbid diseases, and smoking history were recorded.

Results

AVN was found in 11 of 127 (8.7%) SLE patients. Hyperlipidemia (P < 0.001), cushingoid body habitus (P < 0.001), and proteinuria (P = 0.013) were found at higher rates in the AVN group. All of the 11 AVN cases had osteoporosis (P < 0.02). In multivariate regression analysis, daily steroid usage was the only factor for development of AVN in SLE.

Conclusion

The hypothesis of our study was that an alternate day steroid regimen may decrease AVN frequency in SLE patients.

Acetabular Anatomical Parameters in Patients With Idiopathic Osteonecrosis of the Femoral Head

BACKGROUND

Osteonecrosis of the femoral head (ONFH) is an increasing worldwide health problem. However, about 30% of the patients are diagnosed with idiopathic ONFH, which means no underlying etiology is identified. We hypothesized that acetabular anatomical abnormalities might be related to idiopathic ONFH.

METHODS

This retrospective, 1:2 matched, case-control study included 101 patients (136 hips) with idiopathic ONFH and 202 control subjects (404 hips) matched for age, gender, and body mass index who had no apparent radiographic hip pathologies. The anteroposterior pelvic X-rays of the patients and control subjects were used to measure the anatomical parameters including the center-edge angle, the sharp angle, the acetabular depth ratio (ADR), and the acetabular head index (AHI).

RESULTS

We found that hips with idiopathic osteonecrosis had less acetabular coverage, lower center-edge angle (28.3° vs 32.3°, P < .001), acetabular depth ratio (298.0 vs 306.4, P = .006), and acetabular head index (82.2 vs 85.8, P < .001), and higher sharp angle (39.7° vs 38.0°, P < .001), compared with the control subjects. The incidence of acetabular dysplasia was also higher in the idiopathic ONFH group than the control group.

CONCLUSION

Less acetabular coverage was found in hips with idiopathic osteonecrosis than the control subjects. Less acetabular coverage may be associated with the development of ONFH in East Asian population.

Evaluating the association between avascular necrosis of femoral head and oral corticosteroids use in Taiwan

The aim of this study was to assess a correlation between avascular necrosis of femoral head and oral corticosteroids use in the general population in Taiwan. A population-based case-control study was performed to analyze the database of Taiwan National Health Insurance Program. The study consisted of 3002 subjects aged 20 to 84 with newly diagnosed avascular necrosis of femoral head between 2000 and 2013 as the cases and 11279 sex-matched and age-matched subjects without avascular necrosis of femoral head as the matched controls. Use of oral corticosteroids was defined as subjects who had at least a prescription for oral corticosteroids before the index date. No use of oral corticosteroids was defined as subjects who did not have a prescription for oral corticosteroids before the index date. The logistic regression model revealed that subjects with avascular necrosis of femoral head were 1.65 times more likely to be exposed to oral corticosteroids than those subjects without avascular necrosis of femoral head (OR 1.65, 95% CI = 1.51-1.80). A sub-analysis revealed that there was a significant association between avascular necrosis of femoral head and increasing cumulative duration of oral corticosteroids for each additional month of use (OR 1.03, 95% CI = 1.02-1.03). A significant association is detected between avascular necrosis of femoral head and oral corticosteroids use in the general population in Taiwan. There is a duration-dependent effect of oral corticosteroids use on the risk of avascular necrosis of femoral head. Clinicians should be aware of the risk of avascular necrosis of femoral head when oral corticosteroids are prescribed for a long time.

Increased COUP-TFII Expression Mediates the Differentiation Imbalance of Bone Marrow-Derived Mesenchymal Stem Cells in Femoral Head Osteonecrosis

Objective

Bone marrow-derived mesenchymal stem cells (BMSCs) have multilineage differentiation potential, which allows them to progress to osteogenesis, adipogenesis, and chondrogenesis. An imbalance of differentiation between osteogenesis and adipogenesis will result in pathologic conditions inside the bone. This type of imbalance is also one of the pathological findings in osteonecrosis of the femoral head (ONFH). Chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) was previously reported to mediate the differentiation of mesenchymal stem cells. This study investigated the expression of the osteogenesis regulator Runx2, osteocalcin, the adipogenesis regulator PPARγ, and COUP-TFII in the femoral head tissue harvested from ONFH patients, and characterized the effect of COUP-TFII on the differentiation of primary BMSCs.

Methods

Thirty patients with ONFH were recruited and separated into 3 groups: the trauma-, steroid- and alcohol-induced ONFH groups (10 patients each). Bone specimens were harvested from patients who underwent hip arthroplasty, and another 10 specimens were harvested from femoral neck fracture patients as the control group. Expression of the osteogenesis regulator Runx2, osteocalcin, the adipogenesis regulator PPARγ, C/EBP-α, and COUP-TFII was analyzed by Western blotting. Primary bone marrow mesenchymal cells were harvested from ONFH cells treated with COUP-TFII RNA interference to evaluate the effect of COUP-TFII on MSCs.

Results

ONFH patients had significantly increased expression of the adipogenesis regulator PPARγ and C/EBP-α and decreased expression of the osteogenesis regulator osteocalcin. ONFH bone tissue also revealed higher COUP-TFII expression. Immunohistochemical staining displayed strong COUP-TFII immunoreactivity adjacent to osteonecrotic trabecular bone. Increased COUP-TFII expression in the bone tissue correlated with increased PPARγ and decreased osteocalcin expression. Knockdown of COUP-TFII with siRNA in BMSCs reduced adipogenesis and increased osteogenesis in mesenchymal cells.

Conclusion

Increased COUP-TFII expression mediates the imbalance of BMSC differentiation and progression to ONFH in patients. This study might reveal a new target in the treatment of ONFH.

Serum levels of carotenoids in patients with osteonecrosis of the femoral head are lower than in healthy, community-living people

PURPOSE

Oxidative stress is closely associated with the pathogenesis of nontraumatic osteonecrosis of the femoral head (ONFH). This study aimed to determine whether the serum levels of antioxidant nutrients were decreased in patients with ONFH.

METHODS

We analyzed the serum levels of antioxidant nutrients in 39 patients with ONFH (ONFH group) and 78 age- and gender-matched healthy people (control group) who voluntarily participated in the Yakumo study, which is a comprehensive health examination program. We measured and compared the serum levels of α-tocopherol (vitamin E) and total carotenoids, including zeaxanthin/lutein, β-cryptoxanthin, lycopene, α-carotene, and β-carotene, in the ONFH and control groups using high-performance liquid chromatography.

RESULTS

The mean serum levels of total carotenoids were significantly lower in the ONFH group than in the control group (2.36 ± 1.26 and 3.79 ± 2.36 µmol/l, respectively, p < 0.001). However, no significant difference was found in α-tocopherol between the two groups (26.37 ± 6.90 µmol/l in the ONFH group and 26.24 ± 6.28 µmol/l in the control group, p = 0.920). Among each carotenoid, the serum levels of zeaxanthin/lutein, lycopene, and β-carotene were significantly lower in the ONFH group than in the control group ( p < 0.001).

CONCLUSIONS

The serum levels of carotenoids were lower in patients with ONFH than in healthy, community-living people. This result suggests that carotenoids may be related to the pathogenesis of ONFH.

Osteonecrosis of the femoral head: pathophysiology and current concepts of treatment

Osteonecrosis of the femoral head is a disabling pathology affecting a young population (average age at treatment, 33 to 38 years) and is the most important cause of total hip arthroplasty in this population. It reflects the endpoint of various disease processes that result in a decrease of the femoral head blood flow.The physiopathology reflects an alteration of the vascularization of the fine blood vessels irrigating the anterior and superior part of the femoral head. This zone of necrosis is the source of the loss of joint congruence that leads to premature wear of the hip.Several different types of medication have been developed to reverse the process of ischemia and/or restore the vascularization of the femoral head. There is no consensus yet on a particular treatment.The surgical treatments aim to preserve the joint as far as the diagnosis could be made before the appearance of a zone of necrosis and the loss of joint congruence. They consist of bone marrow decompressions, osteotomies around the hip, vascular or non-vascular grafts.Future therapies include the use of biologically active molecules as well as implants impregnated with biologically active tissue. Cite this article: EFORT Open Rev 2019;4:85-97. DOI: 10.1302/2058-5241.4.180036.

Etiologic Classification Criteria of ARCO on Femoral Head Osteonecrosis Part 1: Glucocorticoid-Associated Osteonecrosis

BACKGROUND

Glucocorticoid usage, a leading cause of osteonecrosis of the femoral head (ONFH), and its prevalence was reported in 25%-50% of non-traumatic ONFH patients. Nevertheless, there have been no unified criteria to classify glucocorticoid-associated ONFH (GA-ONFH). In 2015, the Association Research Circulation Osseous addressed the issue of developing a classification scheme.

METHODS

In June 2017, a task force was set up to conduct a Delphi survey concerning ONFH. The task force invited 28 experts in osteonecrosis/bone circulation from 8 countries. Each round of the Delphi survey consists of questionnaires, analysis of replies, and feedback reports to the panel. After 3 rounds of the survey, the panel reached a consensus on the classification criteria. The response rates were 100% (Round 1), 96% (Round 2), and 100% (Round 3), respectively.

RESULTS

The consensus on the classification criteria of GA-ONFH included the following: (1) patients should have a history of glucocorticoid use >2 g of prednisolone or its equivalent within a 3-month period; (2) osteonecrosis should be diagnosed within 2 years after glucocorticoid usage, and (3) patients should not have other risk factor(s) besides glucocorticoids.

CONCLUSION

Association Research Circulation Osseous established classification criteria to standardize clinical studies concerning GA-ONFH.

Epidemiological Profile of Femoral Head Osteonecrosis in the North Indian Population

BACKGROUND

There are limited studies on the epidemiology of femoral head osteonecrosis in Indian population. This study was designed to look for the risk factors of osteonecrosis hip and to assess the severity as per radiological staging (Association Research Circulation Osseous [ARCO]) and clinical score (Harris hip score [HHS]).

MATERIALS AND METHODS

249 patients (382 hips) of osteonecrosis femoral head (ONFH) who were evaluated at our center between January 1, 2005, and June 30, 2013, were included in this retrospective study. The details of history, clinical examination, radiological grading, and HHS were entered into a proforma.

RESULTS

The mean age was 34.71 years (range 14-70 years) and 70.28% (n=175) patients were between 20 and 40 years. Male to female ratio was 5:1. Bilateral ONFH was observed in 53.41% (n=133) patients. In atraumatic conditions, bilateral involvement was seen in 61.61% (130/211) patients. Steroid administration (37.3%, 93/249) was most commonly observed in the patients followed by idiopathic in 21.3% (53/249) patients, chronic alcohol consumption in 20.1% (50/249) patients, and trauma in 15.3% (38/249) patients. There were 48% (185/382) hips in ARCO Stage 2 followed by 33% (125/382) in Stage 3 and 16% (61/382) in Stage 4. The mean HHS was 80.97 ± 14.35 in unilateral ONFH. The mean HHS was 72.79 ± 14.43 and 80.07 ± 13.52 in more involved hip and in less involved hip, respectively, in bilateral ONFH. The ARCO staging had statistically significant correlation with HHS (Pearson's correlation coefficient r = -0.783, P < 0.01) in unilateral ONFH patients and more severely affected hip in bilateral (Pearson's correlation coefficient r = -0.654, P < 0.01) ONFH, but it did not show any association with less involved hip in bilateral cases.

CONCLUSION

ONFH in the North Indian patients is a disease of young individuals with male predominance. Steroid intake is most commonly observed in these patients followed by idiopathic, chronic alcohol consumption, and trauma.

Risk factor analysis for postoperative complications requiring revision surgery after transtrochanteric rotational osteotomy for osteonecrosis of the femoral head

BACKGROUND

This study investigated the risk factors for postoperative complications requiring revision surgery within 3 years after transtrochanteric rotational osteotomy (TRO) for osteonecrosis of the femoral head (ONFH).

METHODS

We reviewed 127 patients (147 hips) who underwent TRO (anterior or posterior rotational osteotomy) for ONFH between January 2002 and December 2014. Two patients were lost to follow-up, and five patients with progression of femoral head collapse requiring a salvage procedure such as total hip arthroplasty within 3 years after TRO were excluded. The better hip in patients treated bilaterally was also excluded (n = 20) to avoid duplication of patient demographics, leaving 120 hips (120 patients) for the analysis. We reviewed the medical records of each patient to screen for postoperative complications that required revision surgery within 3 years after surgery, recording the patient's age, sex, body mass index, surgical side, condition of the contralateral hip, previous alcohol intake, previous alcohol abuse, previous corticosteroid use, perioperative corticosteroid use, smoking status, preoperative stage and type of ONFH, preoperative activity level, and preoperative and final follow-up Japanese Orthopaedic Association scores. Differences between cases with and without complications were analyzed.

RESULTS

Eleven (9.2%) cases showed postoperative complications that required revision surgery. The most common complication was deep infection (n = 5), followed by nonunion of the greater trochanter (n = 3), nonunion of the intertrochanteric osteotomy site (n = 2), and femoral head fracture (n = 1). The multivariate analysis showed an independent association between previous alcohol abuse and postoperative complications (odds ratio, 13.5).

CONCLUSION

A correlation might exist between alcohol abuse and complications following a TRO procedure.

Genome-wide Association Study of Idiopathic Osteonecrosis of the Femoral Head

Idiopathic osteonecrosis of the femoral head (IONFH) is an ischemic disorder that causes bone necrosis of the femoral head, resulting in hip joint dysfunction. IONFH is a polygenic disease and steroid and alcohol have already known to increase its risk; however, the mechanism of IONFH remains to be elucidated. We performed a genome-wide association study using ~60,000 subjects and found two novel loci on chromosome 20q12 and 12q24. Big data analyses identified LINC01370 as a candidate susceptibility gene in the 20q12 locus. Stratified analysis by IONFH risk factors suggested that the 12q24 locus was associated with IONFH through drinking capacity. Our findings would shed new light on pathophysiology of IONFH.

TGF‑β1 expression in adults with non‑traumatic osteonecrosis of the femoral head

Non-traumatic osteonecrosis of the femoral head (NONFH) is a common clinical osteoarthropathy. The present study aimed to investigate the association between transforming growth factor β1 (TGF‑β1) and NONFH. Femoral head specimens were collected from patients with NONFH. Patients with traumatic osteonecrosis served as the control. Hematoxylin and eosin (H&E) staining was used to visualize the bone tissue architecture. Immunohistochemistry and densitometry were performed to quantify TGF‑β1 expression in tissues. Flow cytometry was used to detect cluster of differentiation (CD)3+, CD4+ and CD8+ cells, and the ratio of CD4+ to CD8+ T cells in the peripheral blood. H&E staining revealed osteonecrosis, disintegration of osteocytes with karyopyknosis and karyorrhexis, loss of osteocyte lacunae, aberrantly arranged circumferential lamellae, as well as dissolution of the lamellae and subtle osteogenesis in the experimental group, as opposed to the control group. Immunohistochemistry revealed that the expression of TGF‑β1 was significantly reduced in the experimental group (P<0.01). Further, the NONFH group had a decrease in the CD3+ and CD4+ cell populations (P<0.05 and P<0.01, respectively), an increase in the CD8+ cell population (P<0.05), as well as a reduction in the ratio of CD4+ to CD8+ cells (P<0.01). The present study indicated that TGF‑β1 expression was reduced in NONFH. This was associated with impaired repairing capacity of the femoral head and dysregulated subsets of T‑lymphocytes and possible immune functions.

Influence of cigarette smoking on osteonecrosis of the femoral head (ONFH): a systematic review and meta-analysis

BACKGROUND

Current studies demonstrate controversy regarding the relationship between cigarette smoking and osteonecrosis of the femoral head (ONFH).

METHODS

We conducted a meta-analysis to evaluate the association between smoking and ONFH. Relevant articles published before September 2016 were identified by a systematic search of EMBASE and MEDLINE via Ovid. Summary odds ratios (OR) were calculated using random effects models, and study quality was assessed using a modified Newcastle-Ottawa scale.

RESULTS

102 citations were screened and 7 case-control studies were identified and included in the review. When compared with nonsmokers, current smokers had a higher risk of developing ONFH (OR 2.53; 95% confidence interval [CI] 1.68-3.79), as did former smokers (OR 1.82; 95% CI, 1.10-3.00). Within the group of current smokers, those classified as heavy smokers (with a daily number >20 cigarettes/day) demonstrated higher risks of ONFH (OR 2.03; 95% CI, 1.29-3.19), and light smokers classified as smoking <20 cigarettes/day, also demonstrated a higher risk of ONFH when compared with nonsmokers (OR 1.73; 95% CI, 1.06-2.83). When smoking was classified by pack-years, heavy smokers (>20 pack-years) were at a higher risk of ONFH (OR 2.26; 95% CI, 1.24-4.13), but no significant difference in risk was identified in light smokers (<20 pack-years) (OR 1.81; 95% CI, 0.88-3.71) when compared with nonsmokers.

CONCLUSIONS

Our meta-analysis showed that current smokers were at a higher risk of ONFH, this high risk can also be found in former smokers. And heavy cigarette smoking showed a higher risk of ONFH than light smoking.

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.

Screening of the COL2A1 mutation in idiopathic osteonecrosis of the femoral head

Idiopathic osteonecrosis of the femoral head (idiopathic ONFH) is an ischemic disorder resulting in necrosis of the subchondral bone of the femoral head. COL2A1 mutations, including c.3508G>A, have been reported to be involved in its etiology. However, the etiological role of COL2A1 mutations in idiopathic ONFH remains controversial, because the pathology of idiopathic ONFH is ischemic necrosis, not epiphyseal dysplasia usually seen in the diseases caused by COL2A1 mutations. The purpose of this study is to examine whether COL2A1 mutations have causal relation with idiopathic ONFH or not. We recruited 1,451 Japanese patients with idiopathic ONFH, including steroid-, alcohol-, and neither steroid nor alcohol-associated (neither-associated) ONFH. The diagnosis was based on the criteria of the Japanese Research Committee on idiopathic ONFH of the Ministry of Health, Labour and Welfare. By whole-exome sequencing, entire COL2A1 coding regions and flanking introns were analyzed in 49 neither-associated ONFH patients. In addition, the c.3508G>A mutation of COL2A1 was checked in all idiopathic ONFH patients using the invader assay. Whole-exome sequencing did not detect any COL2A1 mutations in the 49 patients. The c.3508G>A mutation was not found in any of the 1,451 patients. In conclusion, COL2A1 is unlikely to cause idiopathic ONFH. Epiphyseal dysplasia of the femoral head caused by COL2A1 mutations may radiographically mimic idiopathic ONFH. COL2A1 mutations should prompt clinical re-evaluation of the patient's phenotype. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:768-774, 2017.

Cirrhosis-related musculoskeletal disease: radiological review

Musculoskeletal problems in patients with liver disease are common; however, they are not so well described in the literature. Therefore, there is a need to collate information on these disorders, as their incidence is on a constant rise and some of these pathologies can severely debilitate the patient's quality of life. These disorders are parietal wall varices with or without bleeding, spontaneous intramuscular haematoma (e.g. rectus sheath), abdominal wall hernia, anasarca, hepatic osteodystrophy, septic arthritis, osteomyelitis, necrotizing fasciitis, osseous metastases from hepatocellular carcinoma etc. While portal hypertension plays a key role in disorders, in others, dysregulation of the coagulation system or a compromised immune system are responsible. Imaging plays an essential role in the assessment of these complications and awareness of these musculoskeletal manifestations is vital for establishing a timely diagnosis and planning of appropriate therapy, as these disorders can significantly impact the morbidity and mortality and also influence candidacy for liver transplantation. We herein comprehensively appraise various musculoskeletal complications associated with chronic liver disease/liver cirrhosis especially from an imaging perspective which, to the best of our knowledge, have not been collectively described in English literature.

Clinical and basic research on steroid-induced osteonecrosis of the femoral head in Japan

BACKGROUND

Steroid (glucocorticoid)-induced osteonecrosis of the femoral head (ONFH) in young adults has been a challenging disorder due to frequent incidence of collapse of the femoral head and resulting dysfunction of the hip joint and impairing quality of life. In Japan, the working group on ONFH in the Specific Disease Investigation Committee under auspices of the Japanese Ministry of Health, Labor and Welfare was founded in 1975, clinical and related basic research on ONFH have been continued for more than 40 years.

EPIDEMIOLOGY AND CLINICAL COURSE

A national epidemiologic survey in 2004 estimated that 2200 new patients per year would be diagnosed with ONFH in Japan. ONFH was associated with steroid intake (51%), heavy alcohol intake (31%), both (3%), and neither (15%). The male-to-female ratio was 5:4, and the peak decades of age at definitive diagnosis were the 40s in male patients and the 30s in females. MRI studies revealed that ONFH would have occurred in early phase after start of steroid administration and no expansion of necrotic lesion within the femoral head in spite of continued steroid use. To standardize ONFH diagnosis and treatment strategy, the Committee established validated diagnostic criteria, a radiological staging system, and type categorization.

TREATMENT OPTIONS

Most symptomatic patients with collapse of the femoral head require various surgical procedures. Joint preserving surgery, such as transtrochanteric rotational osteotomy and curved varus osteotomy, should be the treatment choice for young patients with healthy areas without severe collapse of the femoral head.

CLINICAL AND RELATED BASIC RESEARCH

Clinical and basic research has been performed to determine the pathogenesis of steroid-induced ONFH. Low hepatic CYP3A activity has been reported to significantly contribute to the risk of steroid-induced ONFH. Several gene polymorphisms related to steroid metabolism were shown to be associated with the occurrence of ONFH.

Temporal Trends in Characteristics of Newly Diagnosed Nontraumatic Osteonecrosis of the Femoral Head From 1997 to 2011: A Hospital-Based Sentinel Monitoring System in Japan

BACKGROUND

Nontraumatic osteonecrosis of the femoral head (ONFH) is a rare disorder caused by ischemic necrosis of unknown etiology. A few studies have demonstrated trends in the number of patients with ONFH. However, there are no data on temporal trends in characteristics such as age, gender, and causative factors. To investigate this, we examined data from a multicenter hospital-based sentinel monitoring system in Japan.

METHODS

A total of 3041 newly-diagnosed ONFH patients from 34 participating hospitals who were reported to the system from 1997-2011 were analyzed. We examined age at diagnosis, potential causative factors, and underlying diseases for which patients received systemic steroid administration. Their temporal trends were assessed according to date of diagnosis in 5-year intervals (1997-2001, 2002-2006, and 2007-2011).

RESULTS

The gender ratio and distribution of potential causative factors did not change. Regarding underlying diseases requiring steroid administration, the proportion of patients with systemic lupus erythematosus decreased in males (10% to 6.4%) and in females (37% to 29%). Proportion of patients with renal transplantation fell consistently across the study period in both males (3.8% to 1.2%) and females (3.2% to 0.8%). In contrast, the proportion of patients receiving steroids for pulmonary disease (except asthma) significantly increased in both males (0.5% to 5.5%) and females (0.5% to 3.6%).

CONCLUSIONS

This large descriptive study is the first to investigate temporal trends in the characteristics of ONFH, which provide useful information for future studies.

The utility of clinical features for distinguishing subchondral insufficiency fracture from osteonecrosis of the femoral head

PURPOSE

Subchondral insufficiency fractures of the femoral head (SIF) need to be differentiated from osteonecrosis of the femoral head (ON), since these two conditions have several overlapping characteristics especially in their radiological findings. The purpose of this study was to determine the useful clinical features for differentiating SIF from ON.

METHODS

This study reviewed 44 consecutive patients, aged 60 years or older with a radiological evidence of subchondral collapse of the femoral head. According to the histopathological diagnosis, 22 patients were grouped as SIF and 22 patients as ON. A 2 × 2 contingency table analysis was used to obtain the odd ratios (ORs) for SIF compared to ON.

RESULTS

The age, proportion of females, the rate of a history of neither corticosteroid intake nor alcohol abuse, and the presence of vertebral compression fracture in subchondral insufficiency fracture were significantly higher than those with osteonecrosis (p = 0.0001, 0.0212, 0.0001, and 0.0040, respectively). ORs for SIF were 12.01 [95 % confidence intervals (CI) 1.35-106.80] and 7.29 (95 % CI 1.91-27.86), if the patient were female and 70 years of age or older, respectively. In addition, OR for SIF was extremely high (OR 56.01, 95 % CI 6.12-512.87) compared to ON, if the patients have a history of neither corticosteroid intake nor alcohol abuse [corrected].

CONCLUSION

The results of this study indicate that osteoporotic elderly women without any history of corticosteroid intake or alcohol abuse need to first be considered to have subchondral insufficiency fracture when radiographs show a collapse of the femoral head.

The effect of alcohol intake and the use of oral corticosteroids on the risk of idiopathic osteonecrosis of the femoral head

The systemic use of steroids and habitual alcohol intake are two major causative factors in the development of idiopathic osteonecrosis of the femoral head (ONFH). To examine any interaction between oral corticosteroid use and alcohol intake on the risk of ONFH, we conducted a hospital-based case-control study of 71 cases with ONFH (mean age 45 years (20 to 79)) and 227 matched controls (mean age 47 years (18 to 79)). Alcohol intake was positively associated with ONFH among all subjects: the adjusted odds ratio (OR) of subjects with ≥ 3032 drink-years was 3.93 (95% confidence interval (CI) 1.18 to 13.1) compared with never-drinkers. When stratified by steroid use, the OR of such drinkers was 11.1 (95% CI 1.30 to 95.5) among those who had never used steroids, but 1.10 (95% CI 0.21 to 4.79) among those who had. When we assessed any interaction based on a two-by-two table of alcohol and steroid use, the OR of those non-drinkers who did use steroids was markedly elevated (OR 31.5) compared with users of neither. However, no further increase in OR was noted for the effect of using both (OR 31.6). We detected neither a multiplicative nor an additive interaction (p for multiplicative interaction 0.19; synergy index 0.95), suggesting that the added effect of alcohol may be trivial compared with the overwhelming effect of steroids in the development of ONFH.

Cite this article: Bone Joint J 2013;95-B:320–5.

Incidence of nontraumatic osteonecrosis of the femoral head in the Japanese population

OBJECTIVE

To estimate the incidence rate of nontraumatic osteonecrosis of the femoral head (ONFH) in the Japanese population.

METHODS

A survey was conducted to ascertain newly identified patients with nontraumatic ONFH in the Specified Disease Treatment Research Program of Fukuoka Prefecture (population 5 million) between 1999 and 2008. Distributions of age and sex in this population were investigated. Crude incidence rates of nontraumatic ONFH were calculated, and age-adjusted incidence rates were estimated by adjusting the crude values against those for the Japanese standard population in each year.

RESULTS

In Fukuoka Prefecture, 1,244 newly identified patients with nontraumatic ONFH were recruited into the Japanese subsidy program over the span of 10 years. The ratio of men to women was 1.6, comprising 758 men (61%; mean age 48 years) and 486 women (39%; mean age 56 years). The crude incidence rate of nontraumatic ONFH in the 10-year period was 2.58 cases per 100,000 person-years (range 1.54-3.66). The mean age-adjusted incidence rate was 2.51 cases per 100,000 person-years.

CONCLUSION

This study showed that the incidence rate of nontraumatic ONFH was 2.51 cases per 100,000 person-years in the Japanese population.

The pathogenesis of nontraumatic osteonecrosis

Nontraumatic osteonecrosis continues to be a challenging problem causing debilitating major joint diseases. The etiology is multifactorial, but steroid- and alcohol-induced osteonecrosis contribute to more than two thirds of all cases with genetic risk factors playing an important role in many other cases, especially when they contribute to hypercoagulable states. While the exact mechanisms remain elusive, many new insights have emerged from research in the last decade that have given us a clearer picture of the pathogenesis of nontraumatic osteonecrosis of the femoral head. Progression to end stage osteonecrosis of the femoral head appears to be related to four main factors: interactions involving the differentiation pathway of osteoprogenitor cells that promote adipogenesis, decreased angiogenesis, direct suppression of osteogenic gene expression and proliferation of bone marrow stem cells, and genetic anomalies or other diseases that promote hypercoagulable states.

Pronounced risk of nontraumatic osteonecrosis of the femoral head among cigarette smokers who have never used oral corticosteroids: a multicenter case-control study in Japan

BACKGROUND

Cigarette smoking has been linked to an increased risk of nontraumatic osteonecrosis of the femoral head (ONFH) in previous studies. However, the effect of smoking amount, duration and cessation, and interaction with corticosteroids remains unclear. The purpose of this study was to precisely evaluate the effects of smoking and the interaction with corticosteroid use.

METHODS

This was a multicenter, matched case-control study in Japan. Cases were defined as patients who were newly diagnosed with ONFH at an initial visit or during the previous year if they were referred patients. For each case, matched controls were selected from patients without ONFH. The matching conditions were sex, age, and ethnicity. A logistic regression model was used to compute odds ratios (OR) and 95 % confidence intervals (95 % CI).

RESULTS

We compared 72 cases with 244 matched controls. ORs were 3.89 (95 % CI 1.46-10.4) for current smokers, 3.89 (1.22-12.4) for smokers consuming more than 20 cigarettes per day, 4.26 (1.32-13.7) for smokers with 26 pack-years or more, and 3.11 (0.92-11.5) for smokers with a history of 29 years or more, with significant or marginally significant dose-response relationships. OR for current smokers was 10.3 among those who had never used corticosteroids and 1.56 among past or current corticosteroid users (P for interaction 0.010).

CONCLUSIONS

Our results revealed that heavier cigarette smoking was associated with a higher risk of ONFH. The elevated risk from cigarette smoking was markedly pronounced among those who had never used oral corticosteroids.

Osteonecrosis in systemic lupus erythematosus: an early, frequent, and not always symptomatic complication

Osteonecrosis may complicate the course of systemic lupus erythematosus and may contemporaneously affect multiple joints. The major risk factor associated with the development of osteonecrosis is the use of glucocorticoid at high doses. Recent studies using serial MRI, which represents the “gold standard” for the early detection of osteonecrosis, yielded some interesting findings about the natural history of this clinical entity. Osteonecrosis in the majority of the cases is asymptomatic and occurs early in the course of the disease. Its later occurrence is associated with lupus flare that requires the increase of corticosteroid dose. The optimal treatment of osteonecrosis is controversial. In case of silent osteonecrosis involving a small area conservative strategy is usually adequate. When lesions are symptomatic surgical treatment as core decompression or free vascularized fibular grafting is required; extracorporeal shockwave treatment may represent an alternative therapeutic approach. When the lesion has a medium-large dimension or involves a weight-bearing area bone collapse is a common complication requiring total joint replacement. Coadministration of bisphosphonate or warfarin with high doses of corticosteroid might be a promising preventive strategy of osteonecrosis.

Idiopathic and secondary osteonecrosis of the femoral head show different thrombophilic changes and normal or higher levels of platelet growth factors

BACKGROUND AND PURPOSE

Thrombophilia represents a risk factor both for idiopathic and secondary osteonecrosis (ON). We evaluated whether clotting changes in idiopathic ON were different from corticosteroid-associated ON. As platelet-rich plasma has been proposed as an adjuvant in surgery, we also assessed whether platelet and serum growth factors were similar to those in healthy subjects.

METHODS

18 patients with idiopathic ON and 18 with corticosteroid-associated ON were compared with 44 controls for acquired and inherited thrombophilia. Platelet factor 4 (PF4), transforming growth factor-β1, platelet-derived growth factor-BB (PDGF-BB), and vascular endothelial growth factor were assayed in the supernatants of thrombin-activated platelets, in platelet lysates, and in serum from 14 ON patients and 10 controls.

RESULTS

Idiopathic ON patients had higher plasminogen levels (median 118%) than controls (101%) (p = 0.02). Those with corticosteroid-associated ON had significantly higher D-dimer (333 ng/mL) and lower protein C levels (129%) than controls (164 ng/mL, p = 0.004; 160%, p = 0.02). The frequency of inherited thrombophilia was not different from the controls. No statistically significant differences were found between idiopathic and corticosteroid-associated ON. 20 of the 36 ON patients were smokers. (The controls were selected from smokers because nicotine favors hypercoagulability). ON patients had significantly higher serum PF4 levels (7,383 IU/mL) and PDGF-BB levels (3.1 ng/mL) than controls (4,697 IU/mL, p = 0.005; 2.2 ng/mL, p = 0.02).

INTERPRETATION

Acquired hypercoagulability was common in both ON types, but the specific changes varied. The release of GF from platelets was not affected, providing a biological basis for platelet-rich plasma being used as an adjuvant in surgical treatment.

Is liver cirrhosis a risk factor for osteonecrosis of the femoral head in adults? A population-based 3-year follow-up study

BACKGROUND

The relationship between osteonecrosis of the femoral head (OFH) and liver cirrhosis is controversial. The aim of this study was to determine whether liver cirrhosis is associated with the occurrence of OFH.

METHODS

We used the National Health Insurance Database, derived from the Taiwan National Health Insurance program. The study cohort comprised 40,769 adult patients with liver cirrhosis. The comparison cohort consisted of 40,769 randomly selected age- and sex-matched subjects.

RESULTS

During the 3-year follow-up period, there were 321 (0.8%) cirrhotic patients with OFH, and 126 (0.3%) non-cirrhotic patients with OFH (p<0.001). Cox's regression analysis, adjusted by the patients' age, sex, and other confounding factors, showed that the cirrhotic patients had a higher risk for occurrence of OFH than non-cirrhotic patients during the 3-year period (hazard ratio=2.38, p<0.001). In this 3-year study, the incidence density of cirrhotic patients hospitalized for OFH was 3 episodes/1,000 person-year.

CONCLUSION

We conclude that cirrhotic patients have a higher risk for occurrence of OFH than non-cirrhotic patients.