Diagnostic criteria for non-traumatic osteonecrosis of the femoral head. A multicentre study

Borderline Developmental Dysplasia of the Hip: A Risk Factor Predicting the Development and Poor Prognosis after Core Decompression for Idiopathic Osteonecrosis of the Femoral Head

OBJECTIVE

It is unclear whether idiopathic osteonecrosis of the femoral head (ONFH) is associated with borderline developmental dysplasia of the hip (BDDH). This study aimed to compare the incidence of BDDH between patients with idiopathic ONFH and matched control subjects and determine the influence of BDDH on poor prognosis after core decompression (CD).

METHODS

We retrospectively examined 78 consecutive patients (111 hips) with idiopathic ONFH undergoing CD and 1:2 matched with 156 control subjects (222 hips). The anteroposterior pelvic radiographs were used to measure the acetabular anatomical parameters and divide included subjects into BDDH or non-BDDH group. The incidence of BDDH and acetabular anatomical parameters were compared between patients with idiopathic ONFH and matched controls. Clinical outcomes, such as Harris Hip Score (HHS), progression of collapse, and conversion to total hip arthroplasty (THA), were compared between patients with BDDH and without BDDH in the idiopathic ONFH group, with a mean follow-up of 72.1 ± 36.6 months.

RESULTS

Patients with idiopathic ONFH had a significantly higher incidence of BDDH than matched controls (29.7% vs 12.2%, p < 0.001). Less acetabular coverage was also found in patients with idiopathic ONFH than in matched controls as demonstrated by lower CEA (28.5° ± 4.7° vs 33.1° ± 5.7°, p < 0.001), AHI (82.4 ± 5.0 vs 86.3 ± 5.4, p < 0.001), ADR (299.6 ± 28.4 vs 318.8 ± 31.3, p < 0.001), and a higher sharp angle (40.0° ± 3.4° vs 37.4° ± 3.7°, p < 0.001). In patients with idiopathic ONFH, the BDDH group had a significantly lower mean HHS at the last follow-up (83.5 ± 17.4 vs 91.6 ± 9.7, p = 0.015) with a different score distribution (p = 0.004), and a lower 5-year survival rate with both clinical failure (66.7%, 95% CI 52.4%-84.9% vs 83.7%, 95% CI 75.2%-93.1%; p = 0.028) and conversion to THA (74.6%, 95% CI 60.7%-91.6% vs 92.1%, 95% CI 85.6%-99.0%; p = 0.008) as the endpoints than the non-BDDH group.

CONCLUSION

The incidence of BDDH was significantly higher in patients with idiopathic ONFH than matched controls, and idiopathic ONFH patients who underwent CD with BDDH had lower mean HHS as well as 5-year survival rate than those without BDDH. Therefore, BDDH should be considered a risk factor predicting the development of idiopathic ONFH as well as poor prognosis after CD.

Attenuated serum vasoactive intestinal peptide concentrations are correlated with disease severity of non-traumatic osteonecrosis of femoral head

Background and objective

The neuropeptide vasoactive intestinal peptide is a 28-amino acid neuropeptide that has been shown to stimulate bone repair and angiogenesis. The purpose of this study was to explore the potential role of serum VIP concentration in osteonecrosis of femoral trauma (ONFH).

Methods

One hundred five patients diagnosed with non-traumatic ONFH and 103 healthy individuals were enrolled in our study. Serum VIP, tumor necrosis factor-α (TNF-α), interluekin-1 beta (IL-1β), and macrophage colony-stimulating factor (M-CSF) levels also were detected using the commercial ELISA kit. Radiographic progression was evaluated using FICAT classification. The clinical severity of ONFH was assessed by visual analog score (VAS) and Harris Hip Score (HHS). Receiver-operating characteristic (ROC) curve was performed to test the potential diagnostic value of VIP in radiographic progression.

Results

The serum VIP level of patients with non-traumatic ONFH was significantly lower than that of healthy controls. There was no significant difference between the alcohol group, the steroid-induction group, and the idiopathic group. Serum VIP levels were significantly higher in ONFH patients with femoral head pre-collapse stage than collapse stage. Serum VIP levels were significantly lower. FICAT 4 non-traumatic ONFH patients had significantly lower serum concentrations of VIP when compared with FICAT 3 and FICAT 2. Moreover, serum VIP levels were significantly lower in ONFH patients with FICAT 3 than FICAT 2. Serum VIP levels were negatively related to FICAT stage. In addition, serum VIP levels were negatively associated with VAS score and positively associated with HHS score. Last, we found serum VIP levels were negatively associated with serum TNF-α and IL-1β levels. ROC curve analysis indicated that decreased serum VIP could serve as a decent biomarker with regard to the diagnosis of radiographic progression.

Conclusion

Attenuated serum VIP concentrations are correlated with disease severity of non-traumatic ONFH. Decreased serum VIP may serve as a potential indicator of non-traumatic ONFH.

Long-term outcomes of curved intertrochanteric varus osteotomy combined with bone impaction grafting for non-traumatic osteonecrosis of the femoral head

AIMS

We compared the clinical outcomes of curved intertrochanteric varus osteotomy (CVO) with bone impaction grafting (BIG) with CVO alone for the treatment of osteonecrosis of the femoral head (ONFH).

METHODS

This retrospective comparative study included 81 patients with ONFH; 37 patients (40 hips) underwent CVO with BIG (BIG group) and 44 patients (47 hips) underwent CVO alone (CVO group). Patients in the BIG group were followed-up for a mean of 12.2 years (10.0 to 16.5). Patients in the CVO group were followed-up for a mean of 14.5 years (10.0 to 21.0). Assessment parameters included the Harris Hip Score (HHS), Oxford Hip Score (OHS), Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ), complication rates, and survival rates, with conversion to total hip arthroplasty (THA) and radiological failure as the endpoints.

RESULTS

There were no significant differences in preoperative and postoperative HHS or postoperative OHS and JHEQ between the BIG group and the CVO group. Complication rates were comparable between groups. Ten-year survival rates with conversion to THA and radiological failure as the endpoints were not significantly different between groups. Successful CVO (postoperative coverage ratio of more than one-third) exhibited better ten-year survival rates with radiological failure as the endpoint in the BIG group (91.4%) than in the CVO group (77.7%), but this difference was not significant (p = 0.079).

CONCLUSION

Long-term outcomes of CVO with BIG were favourable when proper patient selection and accurate surgery are performed. However, this study did not show improvements in treatment results with the concomitant use of BIG. Cite this article: Bone Joint J 2021;103-B(4):665-671.

Associations between glucocorticoids, antiphospholipid antibodies and femur head necrosis in patients with SLE: a directed acyclic graph-based multicentre study

Background

Osteonecrosis of the femoral head (ONFH) remains a major cause of disability in patients with systemic lupus erythematosus (SLE) and seriously impairs quality of life. This study aimed to investigate associations between glucocorticoids (GCs), antiphospholipid antibodies (aPLs), and ONFH in patients with SLE.

Methods

We conducted a multicentre cohort study on patients with SLE and used a directed acyclic graph-based analysis strategy. Details of GC therapy, aPLs status, other drug administration and other SLE-related characteristics were collected. ONFH occurrence during follow-up was determined by magnetic resonance imaging. Multivariable logistic regression and generalized estimating equation models were performed to assess their effects on ONFH, and a simplified scoring system comprising these factors for short- and medium-term SLE-ONFH prediction was developed by receiver operating characteristic curve analysis.

Results

Of 449 SLE patients with a median follow-up duration of 5.3 years, 41 (9.1%) developed ONFH. Independently risk factors of SLE-ONFH including: average daily GC dose with an adjusted odds ratio (aOR) of 1.1 and 95% confidence interval (CI) of 1.0-1.1; GC therapy duration (3-5 years: aOR 3.3, 95% CI 1.4-7.8; >5 years: aOR 8.0, 95% CI 3.3-19.4); initial intravenous GC (aOR 4.4, 95% CI 1.9-10.1); positive aPLs (aOR 2.8, 95% CI 1.4-5.8); and Arterial hypertension secondary to GC usage (aOR 5.2, 95% CI 1.4-19.1). And we successfully developed the simplified scoring system (SCORE model) with an area under the curve of 0.88 (95% CI 0.82-0.94).

Conclusion

Based on the risk factors involved in the development of SLE-ONFH, a novel SCORE model was developed, which might be helpful for risk stratification of SLE-ONFH in clinical practice.

Evaluation of whole-body modalities for diagnosis of multifocal osteonecrosis-a pilot study

Background

This study aimed to investigate the ability of whole-body bone scintigraphy (WB-BS) in the detection of multifocal osteonecrosis (ON) compared to whole-body magnetic resonance imaging (WB-MRI) and to clarify the characteristics of patients with multifocal ON among those with ON of the femoral head (ONFH) using WB-MRI.

Methods

Forty-six patients who had symptomatic ONFH and underwent surgery in our hospital from April 2019 to October 2020 were included in the study. Data on patient demographics, including age, sex, body mass index (BMI), history of corticosteroid intake, alcohol abuse, smoking, and symptomatic joints, were collected from their medical records. All patients underwent WB-MRI and WB-BS before surgery.

Results

The agreement in the detection of ON by WB-MRI vs the uptake lesions by WB-BS in the hip joints was moderate (κ = 0.584), while that in other joints was low (κ < 0.40). Among the 152 joints with ON detected by WB-MRI, 92 joints (60.5%) were symptomatic, and 60 joints (39.5%) were asymptomatic. Twelve out of the 46 (26.0%) patients had multifocal (three or more distinct anatomical sites) ON. Nonetheless, while WB-BS detected symptomatic ON detected by WB-MRI as uptake lesions in 82.6% (76/92) of the joints, asymptomatic ON detected by WB-MRI was detected as uptake lesions in 21.7% (13/60) of the joints. All patients with multifocal ON had a history of steroid therapy, which was significantly higher than that in patients with oligofocal ON (P = 0.035). The patients with a hematologic disease had multifocal ON at a higher rate (P = 0.015).

Conclusions

It might be difficult for WB-BS to detect the asymptomatic ON detected by WB-MRI compared to symptomatic ON. Considering the cost, examination time, and radiation exposure, WB-MRI might be useful for evaluating multifocal ON. Larger longitudinal studies evaluating the benefits of WB-MRI for detecting the risk factors for multifocal ON are required.

Hip survival after plain core decompression alone versus bone morphogenetic protein and/or bone marrow reinjection with core decompression for avascular osteonecrosis of the femoral head: a retrospective case control study in ninety two patients

INTRODUCTION

Injecting bone marrow or bone morphogenetic protein 7 (BMP) during core decompression for avascular osteonecrosis (AVN) may improve survival. We hypothesized that adding a complementary technique (injection of BMP and/or non-concentrated bone marrow) to core decompression would reduce the number of patients requiring a subsequent total hip arthroplasty (THA).

METHODS

We retrospectively reviewed 92 cases from 2003 to 2018 with a minimum of 2 years of follow-up and an average follow-up of 64 months (24-204). Twenty-four patients had a core decompression (CD) (26.1% (24/92)), 25 had a CD associated with reinjection of bone marrow and BMP (rhBMP7) (27.2% (25/92)), and 43 patients had a CD with bone marrow reinjection (46.7% (43/92)).

RESULTS

Hip survival after CD was 66.3% (61/92) at two years and 59.8% (55/92) at 10 years. CD with bone marrow and BMP reinjection had a better hip survival at ten years (HR: 0.492 (CI95%: 0.254-0.952) p = 0.035). A volume of necrosis greater than 30% (HR = 12.97 (CI95 [3.88-43.3] (p < 0.001))) and a Kerboul angle greater than 60° (HR: 12.5 (CI95 [2.84-54.6] (p < 0.001))) were risk factors for a subsequent THA.

CONCLUSIONS

CD is an interesting non-invasive technique to preserve the native hip after AVN of the femoral head. Reinjection of bone marrow and/or BMP improved CD hip survival.

Joint-preserving procedures for osteonecrosis of the femoral head

Osteonecrosis of the femoral head is a poorly understood condition that may lead to progressive destruction of the hip joint. Its incidence is common between the third and fifth decades of life and it is the diagnosis behind 5–18% of annually performed total hip arthroplasties (THAs) in the USA.

Regarding the high rate of complications of THA in that age group, authors have agreed on the importance of joint-preservation techniques for this disease but techniques vary to establish a generally accepted algorithmic approach.

Surgical head-preserving procedures, core decompression with or without graft, stem cell augmentation, or biologic adjuncts, vascularized bone grafting, and proximal femoral osteotomies have all been published on with heterogeneous results and with limited evidence to date.

Consensus states that the prognosis of patients with osteonecrosis of the femoral head can be significantly improved with early diagnosis and timely intervention.

Cite this article: EFORT Open Rev 2019;4:647-658. DOI: 10.1302/2058-5241.4.180073

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.

Global urinary metabolic profiling of the osteonecrosis of the femoral head based on UPLC-QTOF/MS

INTRODUCTION

Osteonecrosis of the femoral head (ONFH), one of the widespread orthopedic diseases with a decrease in bloodstream to the femoral head, is frequently accompanied by cellular death, trabecula fracture, and collapse of the articular surface. The exactly pathological mechanism of ONFH remains to explore and further identify.

OBJECTIVES

The aim was to identify the global urinary metabolic profiling of ONFH and to detect biomarkers of ONFH.

METHODS

Urine samples were collected from 26 ONFH patients and 26 healthy people. Ultra-performance liquid chromatography-quadrupole time of flight tandem mass spectrometry (UPLC-QTOF/MS) in combination with multivariate statistical analysis was developed and performed to identify the global urinary metabolic profiling of ONFH.

RESULTS

The urinary metabolic profiling of ONFH group was significantly separated from the control group by multivariate statistical analysis. 33 distinctly differential metabolites were detected between the ONFH patients and healthy people. Sulfate, urea, Deoxycholic acid and PE(14:0/14:1(9Z)) were screened as the potential biomarkers of ONFH. In addition, the up/down-regulation of sulfur metabolism, cysteine and methionine metabolism, glycerophospholipid metabolism, and histidine metabolism were clearly be associated with the ONFH pathogenic progress.

CONCLUSION

Our results suggested that metabolomics could serve as a promising approach for identifying the diagnostic biomarkers and elucidating the pathological mechanism of ONFH.

A mathematical model for predicting postoperative leg shortening after curved intertrochanteric varus osteotomy for osteonecrosis of the femoral head

Despite good clinical outcomes associated with curved intertrochanteric varus osteotomy for the treatment of osteonecrosis of the femoral head, post-operative leg-length discrepancy is frequently reported and might reduce patient satisfaction. Although previous report showed that varus angulation affected post-operative leg-length discrepancy, sufficient varus angulation is the most important factor for obtaining a lateral intact portion. Therefore, to ensure better postoperative outcomes, detection of other parameters associated with leg shortening may prove useful. This study aimed to detect other factors influencing post-operative leg-length discrepancy and to develop a theory for pre-operative planning. The study included 42 hips of 36 patients with osteonecrosis of the femoral head [25 men and 11 women; mean age at the time of surgery, 33.8 years (range, 17 to 53 years)]. Patients were assessed their clinical and radiological results bofore and after surgery. Additionally, a mathematical model was developed to predict leg shortening after curved intertrochanteric varus osteotomy based on the degree of varus angulation and the distance between the femoral head and osteotomy arc centers. Predicted and actual leg shortening in patients were compared to verify the accuracy of our model. Post-operatively, mean varus angle was 21.7° (range, 15 to 38°) and mean leg shortening was 1.7 mm (range, -5.1 to 11.4 mm). Univariate analysis showed that varus angulation and lateral shift of the osteotomy arc might influence the degree of leg shortening. Furthermore, mathematically predicted leg shortening significantly correlated with actual leg shortening (r = 0.905, p < 0.001), suggesting the usefulness of our model for predicting complications of curved intertrochanteric varus osteotomy. This study indicates the importance of not positioning the center of the osteotomy arc lateral from the center of the femoral head to minimize leg shortening after curved intertrochanteric osteotomy.

Cementless total hip arthroplasty for osteonecrosis and osteoarthritis produce similar results at ten years follow-up when matched for age and gender

PURPOSE

The aim of this study was to compare the clinical outcomes of cementless total hip arthroplasty (THA) used for the treatment of osteonecrosis of the femoral head (ONFH) and for osteoarthritis (OA) at a mean ten years follow-up.

METHODS

Case-control study of 78 patients (86 hips) who underwent THA for ONFH treatment (ONFH group). Patients were matched for age and sex to 78 patients (86 hips) who underwent THA for OA (OA group). We compared the clinical and patient-reported outcomes, implant survival rates, and rates of complications between the groups.

RESULTS

There were no between-group differences in the Harris Hip Score and in the following patient-reported outcomes at the last follow-up: Japanese Orthopedic Association Hip-Disease Evaluation Questionnaire (JHEQ) pain and movement scores and the Physical Component Summary and Role/Social Component Summary scores of Short Form-36 (SF-36). However, the mental score of the JHEQ, the Mental Component Summary score of SF-36, and The Visual Analog Scale score for satisfaction were lower for the ONFH group than for OA group. The rate of complication was equivalent between the groups: 5% for the ONFH group and 3% for the OA group. The ten year implant survival rate was equivalent between the groups, at 97.5% for the ONFH group and 98.2% for the OA group.

CONCLUSION

The functional outcomes, implant survival, and rate of complications for cementless THAs are comparable at a mean follow-up of ten years for ONFH and OA.

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.

MMP9 polymorphism is associated with susceptibility to non-traumatic osteonecrosis of femoral head in a Chinese Han population

Non-traumatic osteonecrosis of femoral head (ONFH) is an orthopedic refractory disease with escalating morbidity in Chinese Han population. In our case-control study, we examined eight previously identified MMP9 single-nucleotide polymorphisms (SNPs) in 585 non-traumatic ONFH patients and 507 healthy individuals from northern China to determine whether these SNPs associated with the risk of developing non-traumatic ONFH. Genetic model and haplotype analyses were used to evaluate the association between SNPs and non-traumatic ONFH. MMP9 rs2274755 (OR, 0.740; 95% CI, 0.578-0.949; p = 0.017) was associated with a reduced risk of non-traumatic ONFH. After adjusting for age and gender, the logistic regression results showed that rs2274755 associated with a lower risk of non-traumatic ONFH in the dominant (OR=0.71, 95% CI: 0.54-0.94, p=0.016), overdominant (OR=0.73, 95% CI: 0.55-0.96, p=0.026) and log-additive (OR=0.74740; 95% CI, 0.578-0.949; p=0.017) models. In addition, the “TGC” haplotype of rs2274755 was associated with a 0.79-fold decrease in risk while the “CTC” haplotype associated with a 0.65-fold decrease risk of the non-traumatic ONFH. These results provide evidence that the MMP9 SNP at the rs2274755 locus is associated with a decreased risk of non-traumatic ONFH in a Chinese Han population.

Characteristics of bone turnover markers in rapidly destructive coxopathy

The purpose of this study was to clarify bone turnover marker levels in rapidly destructive coxopathy (RDC). Twenty patients with RDC (mean age, 72 ± 11 years; 3 men, 17 postmenopausal women), 111 with osteoarthritis (OA) (age, 60 ± 10 years; 15 men, 13 premenopausal women, 83 postmenopausal women), and 18 with osteonecrosis of femoral head (ON) (55 ± 14 years; 11 men, 3 premenopausal women, 4 postmenopausal women), and 100 patients with femoral neck fracture (FNF) (81 ± 10 years; 27 men, 73 postmenopausal women) were included. Serum tartrate-resistant acid phosphatase 5b (TRACP-5b), bone alkaline phosphatase (BAP), matrix metalloproteinase-3 (MMP-3) levels, and bone mineral density (BMD) of proximal femur and lumbar spine were investigated. TRACP-5b levels were significantly higher in RDC than in OA and ON, whereas BAP levels were higher in RDC than in OA (P < 0.05). MMP-3 levels were higher in RDC and ON than in OA (P < 0.05). TRACP-5b were higher in RDC than OA (P < 0.05) and FNF (P < 0.05) in performing propensity score matching; there were no differences in BMD between RDC and OA. TRACP-5b showed the largest area under the curve (AUC, 0.82) according to receiver operating characteristic (ROC) curve analysis for diagnosing RDC against OA and ON. AUCs of BAP and MMP-3 were 0.78 and 0.74. The respective sensitivities and specificities were 70.0 % and 85.3 % for TRACP-5b (cutoff, 623 mU/dl), 95.0 % and 57.1 % for BAP (13.8 U/l), and 70.0 % and 76.4 % for MMP-3 (52.7 ng/ml). The lack of differences in BMD suggested that high bone turnover marker levels may reflect osteoclast cell activation in RDC hips. Serum TRACP-5b and BAP could be RDC markers.

Degeneration of articular cartilage in osteonecrosis of the femoral head begins at the necrotic region after collapse: a preliminary study using T1 rho MRI

OBJECTIVE

The purpose of this study is to evaluate the role of collapse on the degeneration of articular cartilage in patients with osteonecrosis of the femoral head (ONFH).

MATERIALS AND METHODS

Sixteen hips in 12 patients (four men, eight women; mean age, 34.8 years) with a history of systemic corticosteroid treatment were studied using T1 rho magnetic resonance imaging (MRI). Six hips had collapsed ONFH, five had non-collapsed ONFH, and five had no osteonecrosis (controls). Using oblique coronal images, we divided the articular surface of necrotic femoral heads into a region just above the necrotic bone (necrotic zone) and another above the living bone (living zone). T1 rho value was evaluated for each zone.

RESULTS

The mean T1 rho value in the necrotic zone was significantly higher in the collapsed ONFH group (48.4 ± 2.7 ms) than in the non-collapsed ONFH group (41.0 ± 0.9 ms). In the collapsed ONFH group, the mean T1 rho value was significantly higher in the necrotic zone (48.4 ± 2.7 ms) than in the living zone (43.5 ± 2.5 ms). In the non-collapsed ONFH group, there was no significant difference between the mean T1 rho values of the necrotic and living zones. In the collapsed ONFH group, the mean T1 rho value of the necrotic zone and the interval from pain onset to the MRI examination were positively correlated.

CONCLUSIONS

The current T1 rho MRI study suggested that the degeneration of articular cartilage in ONFH begins at the necrotic region after collapse.

Radiologic and Clinical Features of Misdiagnosed Idiopathic Osteonecrosis of the Femoral Head

Idiopathic osteonecrosis of the femoral head (ONFH) can be correctly diagnosed in accordance with the established criteria. However, some general orthopedic physicians have misdiagnosed patients as having ONFH. The goal of this study was to clarify the radiologic and clinical features of misdiagnosed patients. This study included 50 patients who were referred to the authors' hospital by general physicians with a diagnosis of ONFH. The correct diagnosis was made based on the Japanese Investigation Committee diagnostic criteria for ONFH. Demographic data were compared between patients with and without ONFH. Of the 50 patients, 24 were diagnosed with other diseases: 10 with osteoarthritis, 7 with transient osteoporosis of the femoral head, 4 with rapidly destructive coxopathy, and 3 with subchondral insufficiency fracture. Seventeen patients who did not have ONFH had magnetic resonance imaging findings that showed a bone marrow edema pattern at the femoral head. The mean age of 62.9 years among patients without ONFH was significantly higher than that of 45.2 years among patients with ONFH. There were 18 female patients in the non-ONFH group and 5 female patients in the ONFH group. Bilateral disease was found in 1 patient in the non-ONFH group and 17 patients in the ONFH group. No patients in the non-ONFH group had a history of systemic steroid administration compared with 11 patients in the ONFH group. Clinical features associated with the non-ONFH group were female sex, older age, unilateral disease, and no history of systemic steroid administration. For patients with these features, the diagnosis of ONFH should be made carefully. [Orthopedics. 2017; 40(1):e117-e123.].

What factors predict the failure of curved intertrochanteric varus osteotomy for the osteonecrosis of the femoral head?

INTRODUCTION

The purpose of this study was to examine the 10-year survivorship and clinical outcome after curved intertrochanteric varus osteotomy (CVO) for the osteonecrosis of the femoral head (ONFH), and to determine what factors predict the failure of this procedure.

MATERIALS AND METHODS

We retrospectively reviewed 102 consecutive CVOs in 93 patients diagnosed with ONFH. Mean follow-up duration was 10.1 years (3.0-23.2 years). Factors associated with radiographic failure (secondary collapse and/or osteoarthritic change), conversion to total hip arthroplasty (THA) and low Harris Hip Score (HHS), were assessed. The Kaplan-Meier method was used to estimate survival rate.

RESULTS

Radiographic failure occurred in 27 hips (26.5 %), and 11 hips (10.8 %) were converted to THA. The 10-year survival rate was 91.0 % [95 % confidence interval (CI) 83.4-95.2 %] with conversion to THA as the endpoint and 72.4 % (95 % CI 62.3-80.3 %) with radiographic failure as the endpoint. Mean HHS improved from 70.0 preoperatively to 88.1 at the final follow-up (p < 0.001). Multivariate Cox regression analysis showed that postoperative intact ratio <33.3 % [hazard ratio (HR), 11.17; 95 % CI 4.14-30.14] and center-edge (CE) angle <25° (HR 4.91; 95 % CI 1.92-12.55) were independent factors determining radiographic failure. In addition, the multivariate Cox regression analysis showed that postoperative intact ratio <33.3 % (HR 10.65; 95 % CI 2.24-50.53) and CE angle <25° (HR 7.81; 95 % CI 2.17-28.07) were also factors determining conversion to THA. Worse HHSs of <80 were seen in patients with postoperative intact ratio <33.3 % (p < 0.001), CE angle <25° (p < 0.001), and acetabular head index <75 % (p = 0.006).

CONCLUSIONS

Postoperative intact ratio <33.3 % and CE angle <25° were identified as independent factors determining radiographic failure and conversion to THA. Therefore, these factors must be taken into consideration when selecting patients for CVO.

Patient-reported outcomes of femoral osteotomy and total hip arthroplasty for osteonecrosis of the femoral head: a prospective case series study

Background

Patient-reported scoring systems have recently been used after surgical procedures. The purpose of this prospective study was to evaluate the patient-reported outcomes of femoral osteotomy and total hip arthroplasty (THA) for osteonecrosis of the femoral head (ONFH).

Methods

Forty-two symptomatic ONFH patients with asymptomatic contralateral hip underwent either transtrochanteric anterior rotational osteotomy (ARO) or THA as a primary operation. Of these, 20 patients whose contralateral hips remained asymptomatic at the final follow-up (more than 1 year postoperatively) were recruited to participate in this study. Nine patients were treated with ARO (ARO group) and 11 patients were treated with THA (THA group). Both the Oxford hip score (OHS) and the short form 36 (SF-36) were evaluated preoperatively and at the final follow-up.

Results

The preoperative OHS was 29.1 ± 10.9 and 21.9 ± 9.6 points in the ARO and THA groups, which significantly improved to 38.4 ± 9.4 and 40.3 ± 5.1 points at the final follow-up, respectively. The preoperative physical component summary score was 30.8 ± 12.8 and 17.8 ± 14.5 points in the ARO group and THA groups, which significantly improved to 44.5 ± 10.6 and 43.3 ± 10.4 points at the final follow-up, respectively. The preoperative mental component summary score was 48.0 ± 8.5 and 48.6 ± 11.3 points in the ARO and THA groups, both of which remained unchanged at the final follow-up.

Conclusions

The short-term patient-reported outcomes of this study suggested that both ARO and THA for ONFH resulted in significantly improved postoperative hip joint function.

Impaired osteogenic differentiation associated with connexin43/microRNA-206 in steroid-induced avascular necrosis of the femoral head

Connexin(Cx)43 and microRNA(miR)-206 play an important role in osteogenesis. However, their role in steroid-induced femoral head osteonecrosis (SANFH) is still ambiguous. The present study aimed to establish a rabbit model and investigate osteogenesis in steroid-induced femoral head osteonecrosis occurring via Cx43/miR-206 and the changes of Wnt/β-catenin signal pathway-related proteins. A total of 72 adult New Zealand white rabbits were divided randomly into a model group (Group A) and a control group (Group B) of 36 rabbits each. Group A was injected intravenously with lipopolysaccharide (10μg/kg body weight, once per day). After 48h, three injections of methylprednisolone (MPS; 20mg/kg body weight) were administered intramuscularly at 24-hour intervals. Group B were fed and housed under identical conditions but received saline injections. All animals were sacrificed at two, four, and eight weeks from the first MPS injection. Typical early osteonecrosis symptoms were observed in Group A. The expression of miR-206 in Group A was significantly higher than that of Group B. The mRNA and protein levels of Cx43, β-catenin, runt-related transcription factor 2, and alkaline phosphatase gradually decreased while Dickkopf-1 (Dkk-1) gradually increased in Group A compared with Group B. These findings indicated that Cx43/miR-206 is involved in the pathogenesis of early stage SANFH and may be associate with Wnt/β-catenin signal pathway.

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.

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.

MRI-detected bone marrow changes within 3 weeks after initiation of high-dose corticosteroid therapy: a possible change preceding the subsequent appearance of low-intensity band in femoral head osteonecrosis

Osteonecrosis of the femoral head is considered to occur early during the course of corticosteroid treatment. However, it remains unclear exactly how early it can develop after initiation of corticosteroid treatment. We report a case of osteonecrosis of the femoral head in which abnormal findings were observed on short-tau inversion recovery (STIR) sequence image performed 2 weeks and 4 days after initiation of high-dose corticosteroid therapy. A 45-year-old man with hemophagocytic syndrome was started on prednisolone, with a maximum dose of 40 mg/day. On day 13 after initiation of this corticosteroid therapy, he transiently experienced left hip pain with no apparent cause. STIR sequence image 5 days after the onset of pain revealed high-intensity bone marrow lesions at the femoral neck of both hips. At 3 months after initiation of corticosteroid therapy, T1-weighted magnetic resonance imaging revealed concave-shaped low-intensity bands, which corresponded to the preceding high-intensity lesions on both hips. Because of the subsequent progression to collapse of the left femoral head, he underwent prosthetic replacement surgery. The high-intensity lesions on STIR sequence image indicate the possibility that osteonecrosis can occur within 3 weeks after initiation of high-dose corticosteroid therapy.

Low femoral antetorsion as a risk factor for bony impingement after bipolar hemiarthroplasty

Introduction

Reports of dislocation after bipolar hemiarthroplasty (BHA) abound in literature, and several studies have mentioned the factors that are associated with an increased risk of dislocation. However, there is no report detailing the pattern of impingement in BHA and how femoral antetorsion can affect the range of motion (ROM) after BHA.

Purpose

The purpose of this study was to evaluate the pattern of impingement in BHA and whether femoral antetorsion affects the ROM after BHA using three-dimensional (3D) dynamic motion analysis.

Methods

Using the computed tomography (CT) data of 60 patients (60 hips), including 31 men and 29 women who underwent BHA for the treatment of idiopathic osteonecrosis (ION) of the femoral head, we calculated the antetorsion of the femoral neck, ROM of flexion (Flex), internal rotation (Int-R), and external rotation (Ext-R) using a CT-based 3D simulation software. We evaluated the pattern of impingement and the relationship between femoral antetorsion and ROM in BHA. As for the implant position in the 3D simulation software, the anteversion of the femoral implant was set to be the same as the natural antetorsion of the femoral neck and neck length was set to be the standard neck in all cases.

Results

This study revealed the mechanism of impingement in BHA: (1) bone to bone impingement and (2) implant to bone impingement. We found a significant decrease in the ROM of Flex and Int-R inversely proportional to the femoral antetorsion. In patients with lower femoral antetorsion, the ROM of Flex and Int-R decreased due to bony impingement (the anterior great trochanteric region of the femur impinges on the anteroinferior edge of the anteroinferior iliac spine). Whereas, high anteversion of the femoral implant may decrease the ROM of Ext-R; however, our results also showed that even the lowest ROM of Ext-R with 10° hip extension was over 40°.

Conclusions

We demonstrated that lower femoral antetorsion substantially affects the ROM of Flex and Int-R due to bony impingement. For these patients, there should be consideration given to retaining femoral “anterior offset” in BHA.

Apoptosis associated with Wnt/β-catenin pathway leads to steroid-induced avascular necrosis of femoral head

Background

The objective of the current study was to establish a rat model to investigate apoptosis in steroid-induced femoral head osteonecrosis occurring via the Wnt/β-catenin pathway.

Methods

Male Sprague–Dawley (SD) rats were randomly divided into a control group (group A), model group (group B) and sFRP1 group (group C), each consisting of 24 rats, and the rats were intravenously injected with LPS (10 μg/kg body weight). After 24 h, three injections of MPS (20 mg/kg body weight) were administered intramuscularly at 24-h intervals. The rats in group C were injected intramuscularly with 1 μg/kg sFRP1 protein per day for 30 days, beginning at the time of the first MPS administration. The group A rats were fed and housed under identical conditions but received saline injection. All animals were sacrificed at weeks 2, 4 and 8 from the first MPS injection. Histopathological staining was preformed to evaluated osteonecrosis. Apoptosis was detected via quantitative terminal deoxynucleotidyl transferase (TdT) deoxyuridine triphosphate nick-end labelling (TUNEL) staining, caspase-3 activity assay, and detection of Bcl-2 and Bax protein expression by immunohistochemistry and Western blotting. Wnt/β-catenin pathway signalling molecules, including activated β-catenin and c-Myc, were detected by immunohistochemistry and Western blotting.

Results

Typical osteonecrosis was observed in groups B and C. Apoptosis gradually increased with increasing time in both groups B and C. More severe osteonecrosis and apoptosis were observed in group C compared with group B. The expression levels of caspase-3 and Bax were higher while that of Bcl-2 was lower in group C compared with group B. The expression levels of activated β-catenin and c-Myc gradually decreased with increasing time in both groups B and C, and they were lower in group C compared with group B.

Conclusions

The Wnt/β-catenin pathway is involved in the pathogenesis of early stage SANFH, as we have demonstrated in an SANFH rat model, and it may act through the regulation of c-Myc, which affects the cell cycle and cell apoptosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-015-0606-2) contains supplementary material, which is available to authorized users.

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.

Epidemiology of nontraumatic osteonecrosis of the femoral head in Japan

OBJECTIVES

To elucidate the epidemiology of nontraumatic osteonecrosis of the femoral head (ONFH), and to estimate the annual incidence rate in Japan.

METHODS

We examined, over the course of 3 years, personal records and radiographic images from the national registry of documents used for the study of nontraumatic ONFH in patients in Aichi Prefecture, Japan (population: 7.4 million). Those patients not meeting the diagnostic criteria according to the Japanese Investigation Committee for nontraumatic ONFH were excluded from this study.

RESULTS

A total of 285 out of the 327 patients who applied for the national registration of nontraumatic ONFH during the 3-year study met the diagnostic criteria for personal records, radiographic images, and magnetic resonance images. Forty-two patients (12.8%) were not considered to have nontraumatic ONFH. The mean age of patients was 50.4 years, and the male-female ratio was 2.1:1. Nontraumatic ONFH was steroid-induced in 135 cases (47.4%), alcohol-associated in 87 cases (30.5%), steroid-induced and alcohol- associated in 14 cases (4.9%), and idiopathic in 49 cases (17.2%).

CONCLUSIONS

The age-adjusted annual incidence of nontraumatic ONFH in Aichi Prefecture was estimated at 138.5 patients.Thus the annual incidence rate in Japan (population 128 million) was 1.91/100,000.

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

BACKGROUND AND PURPOSE

It has been suggested that avascular osteonecrosis (AVN) of the femoral head occurs early after systemic steroid administration. The purpose of this study was to investigate the risks regarding development of AVN at a very early stage after renal transplantation.

METHODS

The presence or absence of AVN was determined by MRI at 4 weeks, at 6-12 weeks, at 24 weeks, and at 12 months after renal transplantation in 286 patients (183 males) with a mean age of 39 (16-65) years. The relationship between AVN and age, sex, absence or presence of acute rejection (AR), type of transplanted kidney (living or cadaveric), type of immune suppressor, and total dose of orally administered steroids given in the 2-week period after transplantation was investigated.

RESULTS

There were no statistically significant correlations between the development of AVN and age, sex, absence or presence of AR, type of transplanted kidney, or type of immune suppressor. A significant dose-response relationship was found between development of AVN and the total dose of steroid administered in the first 2 weeks after surgery.

INTERPRETATION

We found a relationship between AVN development and steroid dose in the early postoperative period, and we also showed a dose-response relationship.

Administration of erythropoietin exerts protective effects against glucocorticoid-induced osteonecrosis of the femoral head in rats

Accumulating evidence has indicated that erythropoietin (EPO) plays a role in anti-apoptosis and tissue protection in a number of human diseases. The present study was implemented to evaluate these anti-apoptotic and tissue-protective effects in glucocorticoid-induced osteonecrosis in rats. Osteonecrosis was induced by low-dose lipopolysaccharide and subsequent high-dose methylprednisolone pulse. Rats in the preventive group were treated with 500 U/kg/day recombinant human EPO (rhuEPO) for 1 week. Hematological and histomorphometric methods were then used to determine the effects of the administration of rhuEPO. An analysis of trabecular bone architecture was performed to evaluate bone mass change in the osteonecrosis zone. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay was performed to determine the apoptotic index of osteoblasts and osteocytes. Immunoblot analysis was performed to assess the expression of caspase-3 and vascular endothelial growth factor (VEGF) in the femoral head. Treatment with rhuEPO greatly improved the histological performance. Additionally, the incidence of osteonecrosis markedly decreased in the rats in the rhuEPO-treated group (22.2%) compared with the control group (66.7%). Furthermore, the expression of caspase-3 markedly decreased in the rhuEPO-treated group. Consistently, the apoptosis of osteoblasts and osteocytes, as determined by TUNEL assays, was inhibited following the administration of rhuEPO. By contrast, the expression of VEGF increased in the osteonecrosis zone in the rats treated with rhuEPO. The results from the present study demonstrate that EPO exerts prominent protective effects against glucocorticoid-induced osteonecrosis of the femoral head in rats by inhibiting the apoptosis of osteoblasts and osteocytes and increasing the expression of VEGF.

The clinical and radiographic results of intertrochanteric curved varus osteotomy for idiopathic osteonecrosis of the femoral head

PURPOSE

In this study, postoperative results of intertrochanteric curved varus osteotomy (CVO) for idiopathic osteonecrosis of the femoral head (ION) were studied retrospectively and optimal indication of CVO was considered.

METHODS

Between 1995 and 2011, CVO was performed in 51 patients (53 hips) for the treatment of ION in our department. The patients who had the potential to obtain acetabular coverage of more than one-third of the intact articular surface on pre-operative AP hip radiographs in maximum abduction were considered suitable for this operation. For radiological assessment, a ratio of necrotic volume, a ratio of postoperative intact surface on the weight-bearing area, progression of collapse, shortening length of the lower limb, and lateralization of great trochanter were evaluated.

RESULTS

The mean ratio of necrotic volume was 16.9 %. The mean ratio of postoperative intact surface on the weight-bearing area of the femoral head was 51.7 %. The progression of collapse was observed in two hips (ratio of necrotic volume 10.4, 39.8 %; ratio of postoperative intact area 36.5, 38.1 %). The mean shortening length of the lower limb was 9 mm, and the mean lateralization of great trochanter was 3 mm. One hip (ratio of necrotic volume 11.6 %, ratio of intact area 35.8 %) was converted to THA because of the progression of osteoarthritis at 55 months after CVO.

CONCLUSION

The results of CVO for ION were successful, if this procedure was indicated for cases with intact load-bearing area more than 40 %.

Immune response associated with Toll-like receptor 4 signaling pathway leads to steroid-induced femoral head osteonecrosis

Background

Femoral head osteonecrosis is frequently observed in patients treated with excessive corticosteroids. The objective of the current study was to establish a rat model to investigate the disruption of immune response in steroid-induced femoral head osteonecrosis via Toll-like receptor 4 (TLR4) signaling pathway.

Methods

Male SD rats were divided into the treatment group (group A) and the model group (group B) consisting of 24 rats each, and were injected intramuscularly with 20 mg/kg methylprednisolone (MP) for 8 weeks, once a week. The rats in group A were injected intravenously with 7.5 mg/kg TAK242 before each MP administration. A control group (group N) consisted of 12 rats were received saline injection. All animals were sacrificed 8, 10 and 12 weeks from the first MP injection, respectively. Histopathological analysis was performed and the concentration of tartrate-resistant acid phosphatase (TRAP) in serum was tested. The signaling molecules including TLR4, MyD88, NF-κB p65 and MCP-1 were detected by immunohistochemistry, quantitative real-time PCR and Western blot.

Results

Femoral head osteonecrosis was observed in the model rats, and the concentration of TRAP and positive staining of all signaling molecules increased significantly in group B compared with that in group A and group N. Compare with the control group, the mRNA expressions and protein levels of all signaling molecules were enhanced significantly in group B, but no significant in group A.

Conclusions

Corticosteroids can induce femoral head osteonecrosis by disturbing the immune response via TLR4 signaling pathway. These findings suggest that the disruption of immune response play a role in the pathogenesis of osteonecrosis.

Relationship between preservation of the lateral pillar and collapse of the femoral head in patients with osteonecrosis

It is difficult to predict if and when the femoral head will collapse and whether the collapse can be minimized. This study examined the final outcome of early-stage osteonecrosis of the femoral head (ONFH) using magnetic resonance imaging to verify the relationship between preservation of the lateral pillar and collapse of the femoral head. A midcoronal section of the femoral head was divided into 3 pillars (medial, central, and lateral) on a T1-weighted image. According to the site of necrosis on the lateral pillar, the necrosis was divided into 3 types: I, the necrosis occupies the central and medial pillars, and the lateral pillar is preserved; II, the necrosis partially occupies the lateral pillar; and III, the necrosis totally occupies the lateral pillar. One group of 87 patients (127 hips) with Association for Research on Osseous Circulation (ARCO) stage I ONFH underwent nonoperative treatment and were followed for 3 to 8 years (average, 6.2 years). Another group of 42 patients (72 hips) with ARCO stage I ONFH underwent debridement and impacted bone graft and were followed for 5 to 9 years (average, 7.1 years). In both groups, the more preserved the lateral pillar, the less collapse occurred. The authors concluded that whether ONFH progressed to collapse is determined by preservation of the lateral pillar. The lateral pillar is the keystone for maintaining the sphere of the femoral head and its preservation.

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.

Experimental rat model for alcohol-induced osteonecrosis of the femoral head

Alcohol-induced osteonecrosis of the femoral head (ONFH) is observed in alcohol abusers and patients with alcoholic fatty liver disease. It has been reported that Toll-like receptor 4 (TLR4) signalling plays a crucial role in the pathogenesis of alcoholic fatty liver disease. We previously reported a corticosteroid-induced ONFH rat model, and suggested that TLR4 signalling contributes to the pathogenesis of ONFH. Thus, it is thought that the pathogenesis of alcohol-induced ONFH is probably similar to that of corticosteroid-induced ONFH. The aim of this study was to develop a new animal model for alcohol-induced ONFH and to evaluate the relationship between the pro-inflammatory response via TLRs and the development of ONFH in rats. Male Wistar rats were fed a Lieber–DeCarli liquid diet containing 5% ethanol (experimental group) or dextran (control group) for 1–24 weeks. Histopathological and biochemical analyses were performed. Feeding the ethanol-containing liquid diet resulted in the development of ONFH with hepatic steatosis, hepatic dysfunction and hyperlipidaemia, whereas feeding the dextran-containing diet did not cause ONFH. However, we could not recognize any relationship between the pro-inflammatory response via TLR4 and the development of alcohol-induced ONFH. Thus in this study we have developed a new rat model for alcohol-induced ONFH based on the feeding of an ethanol liquid diet. ONFH was observed within seven days from the start of feeding with 5% ethanol-containing liquid diet. Although this was linked to hepatic steatosis, a TLR4 association was not a feature of this model.

New radiographic index for evaluating acetabular version

BACKGROUND

Several qualitative radiographic signs have been described to assess acetabular retroversion. However, quantitative assessment of acetabular version would be useful for more rigorous research purposes and perhaps to diagnose and treat hip disorders.

QUESTIONS/PURPOSES

We developed a new quantitative index for acetabular version (p/a ratio). We determined the average p/a, compared it with previous radiographic signs for acetabular retroversion, and evaluated its relationship with anatomic acetabular version.

METHODS

We calculated the p/a ratio by measuring p (distance from acetabular articular surface to posterior wall) and a (distance from acetabular articular surface to anterior wall) on plain hip AP radiographs and dividing p by a. P and a were assessed on the perpendicular bisector of the line between the teardrop and the lateral edge of the acetabulum. Using 185 hip radiographs from patients with suspected idiopathic osteonecrosis, we measured p/a and compared it with previous qualitative signs for acetabular retroversion. Using 62 hip CT images from patients with no osteoarthritis, we measured the anatomic anteversion at the height of the central femoral head and investigated its relationship with p/a.

RESULTS

The average p/a was 2.05 in 185 hips, and most patients with a p/a greater than 2.05 had a negative qualitative retroversion sign. A correlation was observed between central anteversion and p/a (r = 0.84).

CONCLUSIONS

We believe this ratio can be considered a simple quantitative parameter to assess acetabular version using plain AP radiographs.

Radiological outcome analyses of transtrochanteric posterior rotational osteotomy for osteonecrosis of the femoral head at a mean follow-up of 11 years

BACKGROUND

This study investigated the radiological factors that correlated with progression of collapse and joint space narrowing after transtrochanteric posterior rotational osteotomy (PRO) for osteonecrosis of the femoral head.

METHODS

This study reviewed 51 hips in 47 patients with a mean follow-up of 11 years (5-20). The subjects included 29 males and 18 females with a mean age of 34 years (12-54) at the time of surgery. The 51 hips were divided into two groups based on the radiological outcome (group I: evidence of progression of collapse and/or joint space narrowing, group II: no evidence of either progression of collapse or joint space narrowing). Both clinical and radiological factors were analyzed by both univariate and multivariable analyses.

RESULTS

Six hips were categorized as group I and 45 hips were categorized as group II. The postoperative intact ratio and preoperative stage were significantly correlated with the radiological outcome in both univariate (P < 0.0001, P = 0.006) and multivariate (P = 0.0014, P = 0.0039) analysis. The cutoff point for the postoperative intact ratio (the minimum ratio required to prevent both progression of collapse and joint space narrowing) was 36.8 %.

CONCLUSIONS

The results of this study indicate that the postoperative intact ratio is one of the main influences on progression of collapse and/or joint space narrowing after PRO, and should be at least 36.8 %. An increased awareness of this critical ratio would be useful for planning the optimal use of this procedure.

A canine model of femoral head osteonecrosis induced by an ethanol injection navigated by a novel template

There is no consensus on how to establish models of osteonecrosis of the femoral head (ONFH) in large mammals. The aim of this study was to investigate the effectiveness of a novel canine model of ONFH, induced by a navigated injection of absolute ethanol. Using three-dimensional reconstruction and rapid prototyping manufacturing techniques, a new template was designed and processed to navigate the ethanol injection. The femoral heads of 18 adult dogs were injected with ethanol. Macroscopic, X-ray and histological examinations were performed at 3, 6, and 9 weeks after the operation. Further, computed tomography (CT), magnetic resonance imaging (MRI), and radionuclide scans were performed 6 weeks postoperatively. Three weeks after the operation, the femoral heads showed evidence of osteonecrosis including increasing numbers of empty lacunae, decreased hematopoietic cells, and destroyed adipose tissue in the medullary cavity, which increased in severity at the subsequent follow-up evaluations at 6 and 9 weeks. Fractured trabeculae and fibrous tissue were noted 9 weeks postoperatively. Image analysis also revealed evidence of osteonecrosis, such as several osteopenic areas with sclerotic rims on the X-ray, several areas of low bone mineral density with sclerosis on the CT scan, increased uptake of the nuclide species in MRI, and an inhomogeneous long T2 signal on the radioisotopic images. Ethanol injection navigated by our novel template was successful in establishing a canine model of ONFH. This model can be used to test new treatment modalities for human ONFH.

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.

Association of hip joint effusion volume with early osteonecrosis of the femoral head

This study aimed to examine the association between hip joint effusion volume and osteonecrosis of the femoral head (ONFH) using the Association Research Circulation Osseous (ARCO) classification. Patients (n = 403) who were diagnosed with ONFH were enrolled between February 2005 and December 2008. Only patients (n = 109) with complete clinical and imaging data and at early to mid ARCO stage (I - III) were eligible for further analysis, including 94 males and 15 females. All the included patients had hip joint radiographic examinations (anteroposterior and frog-leg views) and magnetic resonance imaging scans (axial and coronal views). Out of 109 patients included in this study, 185 hip joints were involved (unilateral disease in 33 patients and bilateral diseases in 76 patients). The patients had a mean age of 39 ± 11 years (range, 13-70). All the affected hip joints exhibited effusion, classified as grade 1 (n = 70, 37.8%), grade 2 (n = 62, 33.5%), and grade 3 (n = 53, 28.7%). The volume of joint effusion varied significantly among stage I, II, and III (X2 = 29.210, P < 0.05). The effusion volume did not differ significantly among stage IIA, IIB, and IIC (X2 = 0.103, P > 0.05), whereas it differed significantly among stage IIIA, IIIB, and IIIC (X2 =11.556, P < 0.05). The volume of hip joint effusion was associated with the ARCO stage, and increased over the staging.

Experimental animal models of osteonecrosis

Osteonecrosis (ON) or avascular necrosis (AVN) is a common bone metabolic disorder, mostly affecting femoral head. Although many biological, biophysical, and surgical methods have been tested to preserve the femoral head with ON, none has been proven fully satisfactory. It lacks consensus on an optimal approach for treatment. This is due, at least in part, to the lack of ability to systematically compare treatment efficacy using an ideal animal model that mimics full-range osteonecrosis of femoral head (ONFH) in humans with high incidence of joint collapse accompanied by reparative reaction adjacent to the necrotic bone in a reproducible and accessible way. A number of preclinical animal ON models have been established for testing potential efficacy of various modalities developed for prevention and treatment of ON before introduction into clinics for potential applications. This paper describes a number of different methods for creating animal experimental ON models. Advantages and disadvantages of such models are also discussed as reference for future research in battle against this important medical condition.

Nationwide epidemiologic survey of idiopathic osteonecrosis of the femoral head

BACKGROUND

Although numerous studies describe the clinical characteristics of idiopathic osteonecrosis of the femoral head (ONFH) in specific study populations, these have not been confirmed in countrywide studies.

QUESTIONS/PURPOSES

We therefore determined: (1) the annual number of patients seeking medical care and number of patients newly diagnosed; and (2) the distribution of the age and gender of the patients, potential causative factors, severity of the disease, and operative procedures performed.

PATIENTS AND METHODS

We conducted a nationwide epidemiologic survey in 2005. The survey included all orthopaedic departments in Japan by stratified random sampling according to the number of beds.

RESULTS

The number of patients who sought medical care for idiopathic ONFH during 2004 was estimated to be 11,400 (95% confidence interval, 10,100-12,800). We obtained clinical information from 1502 of these patients. The peak in age distribution occurred in the 40s. Potential causative factors were systemic steroid administration (51%) and habitual alcohol use (31%). Hip replacement was the most frequently performed procedure (65%). Among patients with a history of systemic steroid administration, systemic lupus erythematosus was reported most frequently (31%) as the underlying disease. Among patients younger than 40 years, steroid use was the most prominent potential causative factor (60%), and hip replacement frequently was performed (45%). A greater proportion of patients with no history of steroid or alcohol use was observed among patients 65 years or older (41%).

CONCLUSIONS

In addition to the disease burden of idiopathic ONFH in Japan, our results confirmed the importance of developing preventive and treatment strategies, especially among the younger population.

LEVEL OF EVIDENCE

Level IV, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

MRI evaluation of collapsed femoral heads in patients 60 years old or older: Differentiation of subchondral insufficiency fracture from osteonecrosis of the femoral head

OBJECTIVE

The purpose of this article is to verify the hypothesis that osteonecrosis and subchondral insufficiency fracture of the femoral head can be differentiated on the basis of their appearance on MRI.

SUBJECTS AND METHODS

Between May 1998 and February 2009, we reviewed 30 consecutive hips in 30 patients, 60 years old or older at the time of onset of hip pain, with radiologic evidence of subchondral collapse of the femoral head and with both MR images and histologic results available. Both clinical and radiologic appearances were investigated. The patients were divided into two groups according to the shape of low-intensity bands on T1-weighted images. The first group showed concavity of the articular surface, which is characteristic of osteonecrosis, and the second group showed an irregular convexity of the articular surface, which is characteristic of subchondral insufficiency fracture.

RESULTS

Sixteen hips (53.3%) showed evidence of osteonecrosis, and 14 (46.7%) showed evidence of subchondral insufficiency fracture, which was consistent with the corresponding histopathologic diagnoses. In all cases of osteonecrosis, the patient had a history of either corticosteroid intake or alcohol abuse. Among patients with subchondral insufficiency fracture, the proportion of women was significantly higher than that among patients with osteonecrosis. A crescent sign (subchondral fracture) was present radiographically in about half of all cases in both groups.

CONCLUSION

The results of the present study suggest that the shape of the low-intensity band on MRI is useful for the differentiating subchondral insufficiency fracture from osteonecrosis. In addition, among osteoporotic elderly women without any history of corticosteroid intake or alcohol abuse, a diagnosis of subchondral insufficiency fracture should be considered.

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

BACKGROUND

Previous studies on corticosteroid use and idiopathic osteonecrosis of the femoral head (ONF) have been conducted involving patients with systemic lupus erythematosus and renal transplantation, among other disorders, which make it possible only to compare high- and low-dose corticosteroids. The main objective here was to estimate the impact of oral corticosteroid use for idiopathic ONF compared to nonuse of corticosteroids. In addition, we investigated the relations between underlying medical conditions and idiopathic ONF.

METHODS

A nationwide multicenter case-control study was conducted in Japan. Cases were defined as patients who visited the cooperative orthopedic department after January 2002 and received a diagnosis of idiopathic ONF after the visit. For each case, up to five matched controls were selected from among patients without idiopathic ONF who consulted the same orthopedic department after the visit of the identified case. The matching conditions were sex, age (5-year age groups), and ethnicity. The subjects' demographic and anthropometric data and histories of medications, diseases, alcohol consumption, and smoking were collected by a structured self-administered questionnaire. A conditional logistic regression model was used to obtain the odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

A total of 73 cases and 250 matched controls completed the questionnaire. After adjustment for the potential confounders, the multivariate OR of oral corticosteroid use compared to nonuse was 20.3 (95% CI 6.73-61.5). Furthermore, a positive association of liver disease with idiopathic ONF was observed with marginal significance (multivariate OR 3.53, 95% CI 0.88-14.1) regardless of oral corticosteroid use, alcohol consumption, and smoking.

CONCLUSIONS

The current findings first revealed the impact of oral corticosteroid use for idiopathic ONF compared to nonuse. However, because the regimen of corticosteroid therapy (dose and duration) could not be assessed, further study is required. An independent role of liver disease was also suggested.

To study the role of dynamic magnetic resonance imaging in assessing the femoral head vascularity in intracapsular femoral neck fractures

Intracapsular femoral neck fractures remain unsolved fractures even after improvement in techniques of diagnosis and internal fixation. Individuals who sustain displaced femoral neck fractures are at high risk of developing avascular necrosis and non-union. Although several methods for predicting the viability of femoral head have been reported, they are not effective or widely used because of unreliability, potential complications and technical difficulties. Dynamic MRI was introduced in the recent past as a simple, non-invasive technique to predict the femoral head viability after the femoral neck fractures. In this study role of dynamic MRI was studied in 30 patients with 31 intracapsular femoral neck fractures. Fractures were divided in to three types according to dynamic curve patterns on MRI evaluation and were followed up for 6 months to 2 years to observe the final outcome. Sensitivity, Specificity and the Accuracy of dynamic MRI in predicting vascularity after femoral neck fracture are 87%, 88% and 87%, respectively. Type A or Type B curve pattern is a positive factor to successful osteosynthesis with p value <0.0001 (Chi-square test). This is a statistically significant value. From this finding it can be suggested that the reliability of dynamic curves A and B in predicting maintained vascularity of femoral head is high. This investigation can be used to predict the vascularity of femoral head after intracapsular femoral neck fractures. There was a good correlation between the outcomes of fractures and dynamic MRI curves done within 48 h of injury. This signifies the role of dynamic MRI in predicting the vascularity of femoral head as early as 48 h. A treatment algorithm can be suggested on the basis of dynamic MRI curves. The fractures with Type C dynamic curve should be considered as fractures with poor vascularity of femoral head and measures to enhance the vascularity of femoral head along with rigid internal fixation should be undertaken to promote revascularization process and better healing of fractures. Patients with these fractures should be on longer non-weight bearing ambulation than other patients. To conclude, the dynamic MRI seems to be reliable, non-invasive, sensitive, specific and accurate method of assessing the femoral head vascularity after intracapsular femoral neck fractures as early as 48 h of injury and to predict the outcome of fractures and may be used as a guideline for management of intracapsular femoral neck fractures.