Corticosteroid administration within 2 weeks after renal transplantation affects the incidence of femoral head osteonecrosis

Effect of Patient Age on Total Hip Arthroplasty Outcomes in Patients Who Have Osteonecrosis of the Femoral Head Compared to Patients Who Have Hip Osteoarthritis

BACKGROUND

Osteonecrosis of the femoral head (ONFH) affects both young and old patients. However, outcomes following total hip arthroplasty (THA) for these patients may vary with age. This study aimed to examine the effect of age on THA outcomes for non-traumatic ONFH patients, an area currently lacking research.

METHODS

Patients who had non-traumatic ONFH undergoing THA with at least 2 years of follow-up were identified using a database and divided into four groups by age. Then, 4 matched control groups of patients who had hip osteoarthritis (OA) were created. Multivariate logistic regression analyses were used to evaluate the rates of medical and surgical complications. Additionally, cohorts with a minimum 5-year follow-up were filtered to obtain further data on surgical outcomes. The study analyzed 85,462 non-traumatic ONFH and 80,120 hip OA patients undergoing THA.

RESULTS

Multiple medical complications in ONFH patients increased with age. Periprosthetic fracture within 2 years increased with age, while 90-day wound complications, 2-year periprosthetic joint infections, dislocations, and revisions decreased. The trends for complications continued at the 5-year follow-up. Compared to OA patients, those who had ONFH had higher risks of most complications, but this discrepancy decreased with age.

CONCLUSIONS

In ONFH patients undergoing THA, medical complications generally rise with age, while most surgical complications, including revisions, decrease. It is notable that ONFH patients experienced more complications than those who had OA, but this difference diminished with age.

Evolutionary course of the femoral head osteonecrosis: Histopathological - radiologic characteristics and clinical staging systems

Osteonecrosis of the femoral head (ONFH) is a recalcitrant ischemic disorder, which could be classified into two major categories: traumatic and nontraumatic. Regardless of different risk factors, it has been testified that ONFH results from primitive vascular problems, leading to temporary or permanent loss of blood supply to bone tissue. Histopathological and microarchitectural alterations ensues, which is a gradual evolutionary process involving bone marrow and osteocyte necrosis, progressive destruction of subchondral bone, unsuccessful reparative process, and eventual articular collapse and degenerative arthritis. Based on the imaging features of ONFH, different classification systems have been developed to evaluate the severity and prognosis of the disease, which is pivotal for implementation of treatment strategy, especially the joint-preserving surgery. However, patients classified with the same severity stage, especially in the peri-collapse stage, sometimes responded differently after similar joint-preserving surgery. The unusual phenomenon may be attributed to the limitation of the current imaging classification systems, which might underestimate the disease severity, especially when referring to the early stages. In this review, we briefly summarize the etiology and pathogenesis of ONFH. The imaging features and staging classification systems of ONFH are also described. More importantly, we focus on histopathological and microstructural alterations of the femoral head, and provide an overview of their essential contribution to ONFH progression. Given the observation of discordance between imaging characteristics and histopathological alterations, a substantial amount of research on the relationship between imaging and histopathological features is required to further modify and revise the current wide-accepted classification systems.

Can large doses of glucocorticoids lead to Perthes? a case report and review of the literature

Background

Perthes disease (Legg-Calvé-Perthes, LCP) is a self-limited and non-systemic disease occurring in the femoral heads of children, which is mainly manifested as an ischemic necrosis of the femoral head epiphysis, leading to subchondral ossification injury of the femoral head.

Case presentation

Here we report a case of 11-year-old child with long-term use of high-dose glucocorticoids. With MRI examination finding the epiphyseal necrosis of right humeral head, femur and tibia, and X-ray examination finding bilateral femoral head necrosis, the child was diagnosed as Perthes disease based on his clinical and imaging data.

Conclusions

Long-term and high-dose glucocorticoids may be one of the causes of Perthes disease.

Etiology of avascular osteonecrosis of the femoral head

Avascular osteonecrosis of the femoral head (ONFH) is one of the causes of hip pain that clinicians need to know about. In many cases, it is a fortuitous discovery when pelvic X-rays is performed for another reason. In the other cases, pain reveals the disease. For the rheumatologist, a major part of the job is to look for a cause. An etiology can be found to ONFH in about 70% of the cases. Some of them are evident and the context give the diagnosis (corticosteroids, alcohol abuse…). However, in many cases, additional tests to imaging are required to make the causal diagnosis. In some cases, the treatment of the cause can prevent the recurrence of the disease.

Correlation between continuation of glucocorticoid treatment and risk of femoral head collapse : A retrospective cohort study of patients with glucocorticoid-induced osteonecrosis of femoral head after hip-preserving interventions

OBJECTIVE

To evaluate the correlation between continuation of glucocorticoid (GC) treatment and risk of femoral head collapse in patients with glucocorticoid-induced osteonecrosis of the femoral head (GIONFH) after hip-preserving interventions.

METHODS

The cohort included patients with GIONFH who had received a hip-preserving intervention between 1 January 2014 and 1 April 2016. All hips were at the non-collapse stage. The independent variable and the dependent variable were postoperative GC use and femoral head collapse (≥3 mm), respectively. Multivariate Cox proportional hazards regression were performed to estimate the association of the variables after adjusting for other covariates.

RESULTS

A total of 27 hips (24 patients) were included for the final data analysis of which 6 hips out of 18 developed femoral head collapse (≥3 mm) in patients who discontinued taking GC postoperatively and 6 hips out of 9 developed collapse (≥3 mm) in those requiring GC treatment postoperatively. In the fully adjusted Cox proportional hazards model, the risk of femoral head collapse (≥3 mm) was higher in participants requiring postoperative GC use than those not requiring GC (hazard ratio, HR 3.7, 95% confidence interval, CI 1.1-13.0).

CONCLUSION

The results of this study demonstrated that patients with GIONFH who continued GC treatment postoperatively had a significantly increased risk of femoral head collapse (≥3 mm) compared to those who discontinued use of GC.

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.

Exploring the Risk Factors for the Misdiagnosis of Osteonecrosis of Femoral Head: A Case-Control Study

Objective

The purpose of the present study was to evaluate the present situation and risk factors for the misdiagnosis of osteonecrosis of femoral head (ONFH), providing the basis for accurate diagnosis of ONFH.

Methods

For this retrospective study, 1471 patients with ONFH were selected from the China Osteonecrosis of Femoral Head Database (CONFHD). These patients had been recruited between July 2016 and December 2018. According to whether or not they were misdiagnosed, the patients were divided into two groups, with 1168 cases (22–84 years old) included in the diagnosis group and 303 cases (21–80 years old) in the misdiagnosis group. Misdiagnosis was measured using the following criteria: (i) the patient had the same symptoms and signs, and the second diagnosis was not consistent with the initial diagnosis within 6 months; and (ii) the patient was admitted to a hospital participating in CONFHD and the previous diagnosis was inconsistent with the diagnosis given by the expert group. Comparisons of age, visual analogue scale for pain, and body mass index between the two groups were performed using a t‐test. Gender, causes of ONFH, primary diseases requiring corticosteroids, methods of corticosteroid use, corticosteroid species, type of trauma, onset side of the disease, pain side, whether symptoms are hidden, and type of imaging examination at the initial visit were compared using the χ²‐test. Years of alcohol consumption, weekly alcohol consumption, and physician title at the initial visit were compared using a Mann–Whitney U‐test. Furthermore, the statistically significant factors were evaluated using multiple regression analysis to investigate the risk factors of misdiagnosis.

Results

A total of 303 patients (20.6%) were misdiagnosed: 118 cases were misdiagnosed as lumbar disc herniation, 86 cases as hip synovitis, 48 cases as hip osteoarthritis, 32 cases as rheumatoid arthritis, 11 cases as piriformis syndrome, 5 cases as sciatica, and 3 cases as soft‐tissue injury. Whether symptoms are hidden (P = 0.038, odds ratio [OR] = 1.546, 95% confidence interval [CI] = 1.025–2.332), physician title at the initial visit (P < 0.001, OR = 3.324, 95% CI = 1.850–5.972), X‐ray examination (P < 0.001, OR = 4.742, 95% CI = 3.159–7.118), corticosteroids (P < 0.001, OR = 0.295, 95% CI = 0.163–0.534), alcohol (P < 0.001, OR = 0.305, 95% CI = 0.171–0.546), and magnetic resonance imaging (MRI) examination (P = 0.042, OR = 0.649, 95% CI = 0.427–0.985) were each found to be associated with misdiagnosis.

Conclusion

Osteonecrosis of the femoral head is easily misdiagnosed as lumbar disc herniation, hip synovitis, hip osteoarthritis, and rheumatoid arthritis. Patient history of corticosteroid use or alcohol abuse and MRI examination at the initial diagnosis may be protective factors for misdiagnosis. Hidden symptoms, physician title at the initial visit (as attending doctor or resident doctor), and only X‐ray examination at the initial diagnosis may be risk factors for misdiagnosis.

Incidence and risk factors for osteonecrosis of the hip in renal transplant patients: a prospective single-centre study

BACKGROUND

There is a lack of evidence about the risk factors associated with osteonecrosis of the femoral head (ONFH).

PURPOSES

To determine the incidence and risk factors for ONFH following renal transplantation (RT).

METHODS

In total, data of 681 RT patients (mean age at surgery, 49.5 ± 13.6 years; 249 women and 432 men) were evaluated to determine the incidence of ONFH. Hip magnetic resonance imaging (MRI) was performed six months after RT. The following potential predictors of ONFH were evaluated: (1) patient's condition at RT; laboratory test results including calcium (Ca), phosphorus (P), calcium-phosphorus product (Ca × P), and intact parathyroid hormone before RT; blood relationship between the patient and donor; and mismatching number of human leukocyte antigens (HLAs), especially HLA class I and class II and (2) dosages of steroids after RT, immunosuppressive regimen, and incidence of acute rejection.

RESULTS

ONFH was observed in 30 hips (21 cases, 3.1%). We successfully matched 63 patients without ONFH. Multivariate logistic regression analysis, adjusted for cumulative dosages of steroids, revealed that mismatching number of HLA (hazard ratio [HR], 1.61; 95% confidence interval [CI], 1.10-2.36; p = 0.014), HLA class II (HR, 3.73; 95% CI, 1.46-9.56; p = 0.001), P before RT (HR, 1.62; 95% CI, 1.02-2.58; p = 0.041), and Ca × P  before RT (HR, 1.06; 95% CI, 1.01-1.11; p = 0.024) were risk factors for ONFH.

CONCLUSION

A greater number of HLA mismatches, HLA class II, serum P, and serum Ca × P were risk factors for ONFH after RT. Therefore, these factors should be evaluated in order to predict ONFH after RT.

Transitional changes in the incidence of hip osteonecrosis among renal transplant recipients

BACKGROUND

Immunosuppressive therapy for renal allograft recipients has changed substantially since the introduction of the anti-CD25 monoclonal antibody, basiliximab. We hypothesized that recent improvements in immunosuppressive treatment may reduce the incidence of osteonecrosis of the femoral head (ONFH). This study aimed to investigate transitional changes in the incidence of OFNH among renal transplant recipients by MRI.

METHODS

Participants comprised 110 patients who had undergone renal transplantation from 2003 to 2012, during which time basiliximab was in regular use at our institute (Recent group), and 232 patients who had undergone RT between 1986 and 2003 (Past group). We compared ONFH incidence between the two groups and evaluated risk factors for ONFH, including immunosuppressants (calcineurin inhibitors, basiliximab, and/or steroids) and postoperative renal function.

RESULTS

Incidence of ONFH was lower in the Recent group (0%) than in the Past group (3.4%; p = 0.043). In the Recent group, age was greater, ABO/human leukocyte antigen incompatibility was worse, while steroid dose was decreased and post-transplant renal function was improved. Cumulative methylprednisolone dose at postoperative week 2 and delayed graft function were identified as risk factors for ONFH.

CONCLUSION

Risk of ONFH after renal transplantation has fallen with the advent of regular use of basiliximab, although this agent does not appear to be a factor directly associated with the incidence of ONFH.

STUDY DESIGN

Clinical prognostic study (Level III case control study).

Epidemiology of osteonecrosis among older adults in Sweden

This study estimated the incidence of osteonecrosis in a Swedish, nationwide cohort of older adults. Osteonecrosis was approximately 10 times more common than in previous studies. The strongest risk factors were dialysis, hip fracture, osteomyelitis, and organ transplantation, but only hip fractures could have contributed substantially to the disease burden.

INTRODUCTION

The aim of this study was to estimate the incidence of osteonecrosis in a Swedish, nationwide cohort of older adults and in a large number of risk groups in that cohort.

METHODS

In this retrospective cohort study, we included everyone who was aged 50 years or older and who was living in Sweden on 31 December 2005. We used Swedish national databases to collect data about prescription medication use, diagnosed medical conditions, and performed medical and surgical procedures. The study outcome was diagnosis of primary or secondary osteonecrosis at any skeletal site. The strength of risk factors was assessed using age- and sex-standardized incidence ratios (SIRs).

RESULTS

The study cohort comprised 3,338,463 adults. The 10-year risk of osteonecrosis was 0.4% (n = 13,425), and the incidence rate was 4.7 cases/10000 person-years (95% confidence interval [CI], 4.6 to 4.7 cases). The strongest risk factors for osteonecrosis were hip fracture (SIR, 7.98; 95% CI, 7.69-8.27), solid organ transplantation (SIR, 7.14; 95% CI, 5.59-8.99), dialysis (SIR, 6.65; 95% CI, 5.62-7.81), and osteomyelitis (SIR, 6.43; 95% CI, 5.70-7.23). A history of hip fracture was present in 21.7% of cases of osteonecrosis, but osteomyelitis, dialysis, and solid organ transplantation were present in only 0.5 to 2% of cases.

CONCLUSIONS

Osteonecrosis was approximately 10 times more common than a small number of previous population-based studies have suggested. The strongest risk factors for osteonecrosis were dialysis, hip fracture, osteomyelitis, and solid organ transplantation, but only hip fractures could have contributed substantially to the disease burden.

Incidence of osteonecrosis and insufficiency fracture of the hip and knee joints based on MRI in 300 renal transplant patients

INTRODUCTION

The purpose of this study was to investigate the incidence of necrosis and insufficiency fracture of the hip and knee using magnetic resonance imaging (MRI) in renal transplant patients.

METHODS

We examined 300 consecutive renal transplant patients using MRI of the hips and knees (T1-weighted coronal MRI) preoperatively and at 3 and 6 months postoperatively. Oblique axial-plane T1-weighted MRI and short-tau inversion-recovery T2-weighted MRI were performed parallel to the femoral neck when distinguishing the osteonecrosis of the femoral head (ONFH) from subchondral insufficiency fracture (SIF) of the femoral head was difficult.

RESULTS

ONFH was observed in 3 hips (3 cases, 1.0%). Osteonecrosis of the knee was observed in 2 knees (1 case, 0.3%). SIF of the femoral head was observed in 5 hips (3 cases, 1.0%). Bilateral simultaneous onset of SIF of the femoral head was observed in 2 cases (0.7%). Insufficiency fracture of the knee was observed in 2 knees (1 case, 0.3%).

CONCLUSIONS

When it was difficult to distinguish ONFH from SIF of the femoral head, oblique axial-plane T1-weighted MRI and the short-tau inversion-recovery T2-weighted MRI parallel to the femoral neck were useful to establish the correct diagnosis.

Avascular osteonecrosis in kidney transplant recipients: Risk factors in a recent cohort study and evaluation of the role of secondary hyperparathyroidism

Avascular osteonecrosis (AVN) is a bone complication that indicates poor functional prognosis. Modern immunosuppressive and steroid-sparing drugs have significantly lowered the occurrence of AVN after kidney transplantation (KT). However, recent data on its incidence rates and risk factors are lacking. Using a large, recent cohort, we sought to investigate AVN incidence and risk factors, with a special focus on mineral and bone disorders. We conducted a cohort study in 805 patients who underwent KT between 2004 and 2014. AVN was identified in 32 patients (4%): before KT in 15 (1.8%) and after KT in 18 (2.2%) cases, including one patient with both. In the group with post-KT AVN, the median time intervals from KT to 1) first symptoms and 2) AVN diagnosis were 12 months [1–99] and 20 months [4–100], respectively. Being overweight/obese, having pre-transplant diabetes or hyperparathyroidism at transplantation, developing acute rejection, and receiving higher cumulative corticosteroid doses were associated with AVN occurrence. Multivariate analysis revealed that BMI ≥ 26 kg/m² and higher cumulative corticosteroid doses were predictive of AVN. In conclusion, overweight/obesity is a strong risk factor for AVN. Despite a low maintenance dose, the use of corticosteroids—mostly for treatment of acute rejection—remains an independent risk factor.

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.

Bone infarction of the hip after hand allotransplantation: A case report

Vascularized composite allotransplantation represents as an emerging field in reconstructive surgery. However, some complications can be associated with the procedure. The authors describe a case of bone infarctions of the bilateral hip joints following the first hand allotransplantation in Taiwan. A 45-year-old man who experienced a traumatic amputation of the distal third of his forearm received a hand transplantation from a brain-dead donor. Immunosuppression included antithymocyte globulins, and bolus methylprednisolone (Solu-Medrol) was used for the induction. The maintenance therapy protocol included systemic tacrolimus, mycophenolate mofetil, and prednisone. The patient discontinued the systemic steroid 15 months after surgery. Two episodes of acute rejections were observed at 105 and 810 days after surgery. These signs disappeared after pulse therapy with Solu-Medrol, titration with tacrolimus, and topical immunosuppressive creams (tacrolimus and clobetasol). However, the patient felt pain in both hips after long periods of standing 30 months after the transplantation. A pelvic radiograph and magnetic resonance imaging revealed avascular necrosis (AVN) in both hip joints. Because of the progressive worsening of the pain, the patient underwent a decompression surgery on the left hip involving a fibula bone graft. The patient underwent a right hip hemi-arthroplasty with a bipolar prosthesis 3 months later. The patient remained in good health without major complications. These findings indicate that systemic steroids and tacrolimus might be the major predisposing factors for the induction of AVN after hand allotransplantation.

Corticosteroid-induced Osteonecrosis of the Femoral Head: Detection, Diagnosis, and Treatment in Earlier Stages

Objective:

This review aimed to provide a current recommendation to multidisciplinary physicians for early detection, diagnosis, and treatment of corticosteroid-induced osteonecrosis of the femoral head (ONFH) based on a comprehensive analysis of the clinical literature.

Data Sources:

For the purpose of collecting potentially eligible articles, we searched for articles in the PubMed, Cochrane Library, Embase, and CNKI databases up to February 2017, using the following key words: “corticosteroid”, “osteonecrosis of the femoral head”, “risk factors”, “diagnosis”, “prognosis”, and “treatment”.

Study Selection:

Articles on relationships between corticosteroid and ONFH were selected for this review. Articles on the diagnosis, prognosis, and intervention of earlier-stage ONFH were also reviewed.

Results:

The incidence of corticosteroid-induced ONFH was associated with high doses of corticosteroids, and underlying diseases in certain predisposed individuals mainly occurred in the first 3 months of corticosteroid prescription. The enhanced awareness and minimized exposure to the established risk factors and earlier definitive diagnosis are essential for the success of joint preservation. When following up patients with ONFH, treatment should be started if necessary. Surgical treatment yielded better results than conservative therapy in earlier-stage ONFH. The ideal purpose of earlier intervention and treatment is permanent preservation of the femoral head without physical restrictions in daily living.

Conclusions:

Clinicians should enhance their precaution awareness of corticosteroid-induced ONFH. For high-risk patients, regular follow-up is very important in the 1^st year after high-dose prescription of corticosteroids. Patients with suspected ONFH should be referred to orthopedists for diagnosis and treatment in its earlier stage to preserve the joint.

Clinical analysis of 23 cases of steroid-associated osteonecrosis of the femoral head with normal initial magnetic resonance imaging presentation

To explore the clinical characteristics of steroid-associated osteonecrosis of the femoral head (ONFH) presenting initially normal magnetic resonance imaging (MRI) results.This retrospective study examined data from 23 cases that suffered from ONFH but presented a normal image at the first MRI examination after corticosteroid therapy from June 2005 to December 2013. Data on protopathy, age, sex, time of pain onset, MRI examination, and initial diagnosis were collected and analyzed.Average time from steroid therapy to first MRI examination was 45.7 ± 25.5 days (range, 10-94 days). Average time to final diagnosis was 199.9 ± 165.8 days (range, 32-762 days). Of the 23 cases, 21 cases complained of discomfort and were misdiagnosed because of a normal initial MRI scan. Twelve hips progressed to collapse and 1 hip received lumbar discectomy when got the final diagnosis. Cases with continuous pain (9/21) presented with pain at a later time than those with intermittent pain (12/21), although the continuous pain cases were diagnosed earlier.MRI performed 2 to 3 months after steroid therapy may present normal images. Another MRI examination is necessary to make a definite diagnosis.

Steroid therapy and the risk of osteonecrosis in SARS patients: a dose-response meta-analysis

This meta-analysis synthesized current evidence from 10 trials to evaluate the association between steroid therapy and osteonecrosis incidence in patients with severe acute respiratory syndrome (SARS). Our results suggest that higher cumulative doses and longer treatment durations of steroids are more likely to lead to the development of osteonecrosis in SARS patients.

INTRODUCTION

The link between steroid treatment and the risk of osteonecrosis in SARS patients remains unknown. The present meta-analysis aimed to examine the dose-response association between steroid therapy and osteonecrosis incidence in SARS patients. The sex differences in the development of steroid-induced osteonecrosis were also examined.

METHODS

We searched PubMed, Web of Science, CNKI, and WANFANG for studies that involved steroid therapy and reported osteonecrosis data in SARS patients. Two authors independently extracted the data from the individual studies, and the rate ratio (RR) of osteonecrosis was calculated using random-effect models.

RESULTS

Ten studies with 1137 recovered SARS patients met the inclusion criteria. Close relationships between osteonecrosis incidence and both the cumulative dose and treatment duration of steroids were observed. The summary RR of osteonecrosis was 1.57 (95% confidence interval (CI) 1.30-1.89, p < 0.001) per 5.0 g increase in the cumulative dose of steroids and was 1.29 (95% CI 1.09-1.53, p = 0.003) for each 10-day increment of increase in treatment duration. The relationship was non-linear (p _non-linear < 0.001 and p _non-linear = 0.022). There were no significant differences in the risk of developing osteonecrosis between the male and female patients (RR 0.01, 95% CI -0.03 to 0.06, p = 0.582).

CONCLUSIONS

SARS patients who received higher cumulative doses and longer treatment durations of steroids were more likely to develop osteonecrosis, and there were no sex differences in this dose-dependent side effect. Our findings suggest that it is important to reduce osteonecrosis risk by modifying the cumulative dose and the treatment duration of steroids in SARS patients.

Guideline for Diagnostic and Treatment of Osteonecrosis of the Femoral Head

There is a new knowledge for clinical presentations and findings of imagine in patients with osteonecrosis of the femoral head (ONFH) in recent more than ten years. According to clinical data in Chinese huge patients with ONFH, the guideline for diagnosis and treatment of ONFH has been put forward by Chinese specialists. The newer contents of guideline include the definition for predisposing risk factors of ONFH, the new knowledge for clinical manifestations, the new interpretation for changes of imagine, important differential diagnosis. Based on the supplementary and revision for widely used staging and classification system, the new Chinese staging and classification system have been established. The advantages of Chinese staging and classification system accord with clinical and pathological features, it could be predicted the prognosis, and clinical applications are convenient. The guideline gives a brief account of principles for treatment selection and treatment methods for enhancement of diagnosis and treatment for ONFH.

Nitric oxide content and apoptosis rate in steroid-induced avascular necrosis of the femoral head

The aim of the present study was to explore the effect on nitric oxide (NO) content and osteocyte apoptosis of steroid-induced avascular necrosis of the femoral head (SANFH) in an animal model of SANFH. A total of 40 Japanese white rabbits, 5 months of age and weighing 2.5±0.5 kg, were randomly divided into groups A (hormone + endotoxin group), B (endotoxin + normal saline group), C (normal saline + hormone group) and D (control group). Following the establishment of the model, a blood sample was taken from the heart of each animal and centrifuged; the levels of NO in the serum were detected. The bilateral femoral heads were conventionally dissected, fixed, decalcified and stained with hematoxylin and eosin. Subsequently, the empty bone lacunae were counted under an optical microscope. Changes in osteocyte morphology were observed using electron microscopy and osteocyte apoptosis was detected with a terminal deoxynucleotidyl transferase dUTP nick end labeling assay. The percentage of empty bone lacunae in group A was significantly higher compared with that in groups B, C and D (P<0.01); however, there was no significant difference in percentage among groups B, C and D. The NO content in group A was significantly higher compared with that in groups B, C and D (P<0.01); however, there was no significant difference in NO content among groups B, C and D. The osteocyte apoptosis index in group A was significantly higher compared with that in the other groups (P<0.01); there was no significant difference among groups B, C and D. NO content was positively correlated with osteocyte apoptosis index (r=0.707). Thus, the present study found that NO content and the osteocyte apoptosis index were increased in SANFH, and that they play an important role in SANFH. The content of NO was positively correlated with the osteocyte apoptosis index, indicating that NO induces apoptosis.