Bone marrow oedema predicts bone collapse in paediatric and adolescent leukaemia patients with corticosteroid-induced osteonecrosis

Efficacy and confounding factors of CT attenuation value differences in distinguishing acute and old vertebral compression fractures: a retrospective study

PURPOSE

To evaluate the influence of various factors on CT attenuation values (HUs) of acute and old fracture vertebra, and to determine the efficacy of HU differences (△HUs) in the differentiation of the two type of fractures.

MATERIALS AND METHODS

A total of 113 acute and 71 old fracture vertebrae confirmed by MRI were included. Four HUs measured at the mid-sagittal, upper 1/3 axial, mid-axial, and lower 1/3 axial planes of each vertebra were obtained. The △HUs between fracture vertebra and its control counterpart was calculated. Receiver operating characteristic (ROC) curve analysis was used and the areas under the ROC curve (AUC) were calculated to evaluate the efficacy of HUs and △HUs. To evaluate the effect of height reduction, region, age and gender on HUs and △HUs, one-way analysis of variance, Pearson correlation analysis and t-test were used.

RESULTS

The HUs and △HUs at the upper 1/3 axial plane achieved the highest AUCs of 0.801 and 0.839, respectively. The HUs decreased gradually from Thoracic to Lumbar in control group of acute fracture. While no significant differences were found in the HUs among the 3 localizations in both fracture groups (all P > 0.05). The HUs were negatively correlated with age in all groups. The HUs of male were significantly higher than female patients in all groups (all P < 0.05). While △HU was not significantly different between males and females (all P > 0.05).

CONCLUSION

The vertebral HUs at the upper 1/3 axial plane are more likely to identify acute fractures. △HUs were beneficial in eliminating interfering factors.

CT and MRI findings beyond the subchondral bone in osteonecrosis of the femoral head to distinguish between ARCO stages 2 and 3A

OBJECTIVES

To determine the diagnostic values of deep changes beyond the subchondral bone in osteonecrosis of the femoral head (ONFH) to distinguish between Association Research Circulation Osseous (ARCO) stages 2 and 3A.

METHODS

This retrospective study included 124 hips with ONFH of stages 2 (n = 49; 23 females; mean age, 50.7 years) and 3A (n = 75; 20 females; mean age, 53.2 years) from May 2017 to August 2022, who underwent CT (n = 124) and MRI (n = 85). Deep changes beyond subchondral bone were analyzed on CT (bone resorption area and cystic change) and on MRI (bone marrow edema [BME] and joint effusion). Diagnostic performance and multivariate analysis were evaluated for detecting stage 3A.

RESULTS

Stage 3A showed more frequent bone resorption area (72.0% vs. 4.1%), cystic change (52.0% vs. 0.0%), BME (93.5% vs. 43.6%), and joint effusion (76.0% vs. 24.5%) than stage 2 (p < 0.001, all). Bone resorption area and cystic change showed low sensitivities (52.0~72.0%) but high specificities (96.0~100.0%), while BME and joint effusion showed high sensitivities (76.0~93.0%) but low specificities (56.0~76.0%) for stage 3A. Predictors were in the order of bone resorption area, cystic change, and joint effusion (odds ratio: 32.952, 26.281, 9.603, respectively), and combined bone resorption area and cystic change had the best predictive value (AUC, 0.900) for stage 3A.

CONCLUSIONS

Among deep changes, bone resorption area and cystic changes were highly specific and BME and joint effusion were highly sensitive for stage 3A. Combined bone resorption area and cystic change had the best predictive value for predicting ARCO stage 3A.

KEY POINTS

• The exact classification between ARCO stage 2 and 3A is essential but it is sometimes difficult to distinguish between ARCO stage 2 and 3A only by subchondral fracture, especially early post-collapse stage with preservation of femoral head contour. • The predictors of stage 3A were in the order of bone resorption area, cystic change, and joint effusion and combined bone resorption area and cystic change had the best predictive value for predicting stage 3A. • Analysis of deep changes beyond the subchondral bone may make it easier to distinguish between ARCO stage 2 and 3A.

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.

Recent perspectives on the association between osteonecrosis and bone mineral density decline in childhood acute lymphoblastic leukemia

The attention to treatment-related toxicity has increased since the survival of children with acute lymphoblastic leukemia (ALL) has improved significantly over the past few decades. Intensive ALL treatment schedules including corticosteroids and asparaginase have been shown to give rise to skeletal abnormalities such as osteonecrosis and low bone mineral density (BMD), which may lead to debilitating sequelae in survivors. Although osteonecrosis and low BMD are different entities with suggested separate pathophysiological mechanisms, recent studies indicate that osteonecrosis is associated with accelerated BMD decline. Common underlying mechanisms for osteonecrosis and BMD decline are considered, such as an enhanced sensitivity to corticosteroids in children who suffer from both osteonecrosis and low BMD. In addition, restriction of weight-bearing activities, which is generally advised in patients with osteonecrosis, could aggravate BMD decline. This induces a clinical dilemma, since bone stimulation is important to maintain BMD but alternative interventions for osteonecrosis are limited. Furthermore, this recent finding of accelerated BMD decline in children with osteonecrosis emphasizes the need to develop effective preventive measures for osteonecrosis, which may include targeting BMD decline.

Is bone mineral density lower in the necrotic lesion in pre-collapse osteonecrosis of the femoral head?

The purpose of this study was to clarify whether bone mineral density (BMD) of the necrotic lesion in precollapse osteonecrosis of the femoral head (ONFH) is reduced according to Hounsfield unit (HU) values on computed tomography (CT). The superior one-third of the femoral head in the coronal section was set as the region of interest (ROI) for the measurement of HU values. First, HU values of 101 control participants were assessed to identify relevant confounding factors. Next, the relationship between HU values and BMD on dual-energy X-ray absorptiometry (DXA) was verified. Then the mean HU value of the ROI in patients with pre-collapse ONFH was compared with that in propensity score-matched control participants. Finally, the HU values of the lateral boundary in the patients with and without subsequent collapse were compared. Multivariable analysis showed that both age and BMI were significantly correlated with the HU value, which showed a strong correlation with the BMD of the femoral neck on DXA (r = 0.92). In 25 ONFH patients and 25 propensity-matched control participants, no significant difference was found in the HU value of the ROI (p = .54). The mean HU value of the lateral boundary in patients with subsequent collapse was found to be significantly higher than that in patients without subsequent collapse (p < .01). The assessment of HU values on CT was useful for the evaluation of BMD of the femoral head. The current assessment did not demonstrate reduced bone mineral density of the necrotic lesion in pre-collapse ONFH.

Digital Subtraction Angiography and Magnetic Resonance Imaging-Based Staging of Circulatory Obstruction in the Femoral Head During Osteonecrosis of the Femoral Head Development

INTRODUCTION

Nontraumatic osteonecrosis of the femoral head (NONFH) is a common and difficult disease in orthopedics. Magnetic resonance imaging (MRI) assessment of NONFH and bone marrow edema was combined with digital subtraction angiography (DSA) to evaluate the circulatory status of NONFH in different Association Research Circulation Osseous stages. Based on the circulatory obstruction status (venous stasis, arterial ischemia, and arterial occlusion), appropriate perioperative management was adopted to achieve hip joint preservation and effectively delay the time for total hip arthroplasty in young patients.

METHODS

From January 2013 to March 2019, 41 orthopedic patients were evaluated for medical imaging. Sixty-one ONFH cases were enrolled. The inclusion criteria include: (1) Clear diagnosis of osteonecrosis of the femoral head. (2) No history of infection in the affected hip, no history of hip surgery, and no congenital hip diseases. The patients enrolled in this study were 8 women and 33 men between the ages of 19 and 64 years (mean, 39.25 ± 8.90 years). Preoperative X-ray, computed tomography, MRI, DSA, and histological data were taken.

RESULTS

The combination of DSA and MRI can efficiently show blood supply changes in the femoral head of NONFH patients at different Association Research Circulation Osseous stages; and also can possibly reveal the causes and development of NONFH. Different stages of circulatory obstruction of the femoral head can be clearly distinguished and used to determine the required perioperative management, thus yielding successful surgical outcomes.

CONCLUSIONS

The existing classification systems do not fully reflect the progression of circulatory obstruction in ONFH. Each stage of NONFH development has its own characteristics circulatory obstruction. Early-stage NONFH displays characteristic venous stasis of the femoral head, whereas advanced stage NONFH is characterized by insufficient arterial blood supply to the femoral head. Corresponding NONFH treatment strategies should be considered based on their specific circulatory status. This work also provides guidance and recommendations for adopting corresponding femoral head preserving strategies for young patients in different NONFH circulatory status.

How We Manage Bone Marrow Edema-An Interdisciplinary Approach

Bone marrow edema (BME) is a descriptive term for a common finding in magnetic resonance imaging (MRI). Although pain is the major symptom, BME differs in terms of its causal mechanisms, underlying disease, as well as treatment and prognosis. This complexity together with the lack of evidence-based guidelines, frequently makes the identification of underlying conditions and its management a major challenge. Unnecessary multiple consultations and delays in diagnosis as well as therapy indicate a need for interdisciplinary clinical recommendations. Therefore, an interdisciplinary task force was set up within our large osteology center consisting of specialists from internal medicine, endocrinology/diabetology, hematology/oncology, orthopedics, pediatrics, physical medicine, radiology, rheumatology, and trauma surgery to develop a consenus paper. After review of literature, review of practical experiences (expert opinion), and determination of consensus findings, an overview and an algorithm were developed with concise summaries of relevant aspects of the respective underlying disease including diagnostic measures, clinical features, differential diagnosis and treatment of BME. Together, our single-center consensus review on the management of BME may help improve the quality of care for these patients.

[Differential diagnoses of osteonecrosis of large joints]

Subchondral insufficiency fractures and idiopathic bone marrow edema syndrome are the most important differential diagnoses to be distinguished from osteonecrosis because they have a deviating and as a rule more favorable prognosis and also different therapeutic strategies. Osteochondritis dissecans represents a different entity in many respects, which should not be confused or unified with osteonecrosis. Based on recent knowledge intractable subchondral insufficiency fractures may be the underlying cause of rapidly destructive osteoarthritis at least in some cases. Septic involvement of bone and joints can eo ipso cause severe articular damage due to direct destruction but also secondary to septic vascular occlusion resulting in septic osteonecrosis. Whereas bone marrow infiltrating systemic diseases and the therapeutic regimens can lead to osteonecrosis, bone tumors or tumor-like diseases, rarely pose a differential diagnostic problem with respect to the differentiation from osteonecrosis.

The radiological and clinical follow-up of osteonecrosis in cancer patients

BACKGROUND

In patients with cancer, osteonecrosis (ON) lesions can affect multiple sites throughout the skeleton, including the long and short bones and the joints. The aims of this study were to explore the natural course of ON in patients treated for cancer by using radiological classification suitable for multisite ON lesions and to assess correlations between the ON grade and surgical procedures.

MATERIAL AND METHODS

Data were retrieved from hospital databases on 233 ON lesions in 54 patients (aged 2-73 years at cancer diagnosis; mean age: 25 years). ONs were graded according to the Niinimäki classification, based on magnetic resonance images. Medical records were reviewed to identify surgical procedures.

RESULTS

A total of 14 different ON sites were detected; the hip was the most common site (n = 51), followed by the femur (n = 45), tibia (n = 41) and knee (n = 37). Among the 233 ON lesions, 78.1% did not require surgical procedures. The remaining lesions required total joint arthroplasty (TJA; 40/233, 17.2%), core decompression (3.4%) and arthroscopy (1.3%). Most TJAs (33/40, 82.5%) were performed on the hip. ONs of the knee required TJAs only once; grade 3 knee ONs frequently healed (58%, 11/19). None of the diaphyseal or metaphyseal (grade 1-2) ONs of the long bones required surgery, and no fractures of those bones were identified.

CONCLUSIONS

In conclusion, the natural history of ONs varied by the grade and site. Based on our findings, we would not recommend routine radiological follow-ups for grades 1-2 ON lesions that do not affect the joints, because the clinical consequences of those lesions appear to be minimal, although pain relief would be warranted. In contrast, joint deformations (grade 5) require surgery; therefore, intervention studies should focus on grades 3-4 ON lesions.

Pericollapse Stage of Osteonecrosis of the Femoral Head: A Last Chance for Joint Preservation

Objective:

To propose a new definition of the pericollapse stage of osteonecrosis of the femoral head (ONFH) and review its significance in disease diagnosis and treatment selection.

Data Sources:

A search for eligible studies was conducted in three electronic databases including PubMed, Cochrane Library, and Embase up to August 10, 2018, using the following keywords: “osteonecrosis”, “prognosis”, and “treatment”.

Study Selection:

Investigations appraising the clinical signs, symptoms, and imaging manifestations in different stages of ONFH were included. Articles evaluating the prognosis of various joint-preserving procedures were also reviewed.

Results:

The pericollapse stage refers to a continuous period in the development of ONFH from the occurrence of subchondral fracture to early collapse (<2 mm), possessing specific imaging features that mainly consist of bone marrow edema and joint effusion on magnetic resonance imaging (MRI), crescent signs on X-ray films, and clinical manifestations such as the sudden worsening of hip pain. Accumulating evidence has indicated that these findings may be secondary to the changes after subchondral fractures. Of note, computed tomography provides more information for identifying possible subchondral fractures than does MRI and serves as the most sensitive tool for grading the pericollapse lesion stage. The pericollapse stage may indicate a high possibility of progressive disease but also demonstrates satisfactory long- and medium-term outcomes for joint-preserving techniques. In fact, if the articular surface subsides more than 2 mm, total hip arthroplasty is preferable.

Conclusions:

The pericollapse stage with distinct clinical and imaging characteristics provides a last good opportunity for the use of joint-preserving techniques. It is necessary to separate the pericollapse stage as an independent state in evaluating the natural progression of ONFH and selecting an appropriate treatment regimen.

The skeletal impact of cancer therapies

Both cancer and therapies used in the treatment of cancer can have significant deleterious effects on the skeleton, increasing the risks for both bone loss and fracture development. While advancements in cancer therapies have resulted in enhanced cancer survivorship for patients with many types of malignancies, it is increasingly recognized that efforts to reduce bone loss and limit fractures must be considered for nearly all patients undergoing cancer therapy in order to diminish the anticipated future skeletal consequences. To date, most studies examining the impact of cancer therapies on skeletal outcomes have focused on endocrine-associated cancers of the breast and prostate, with more recent advances in our understanding of bone loss and fracture risk in other malignancies. Pharmacologic efforts to limit the adverse effects of cancer therapies on bone have nearly universally employed anti-resorptive approaches, although studies have frequently relied on surrogate outcomes such as changes in bone mineral density or bone turnover markers, rather than on fractures or other skeletal-related events, as primary study endpoints. Compounding current deficiencies for the provision of optimal care is the recognition that despite clearly written and straightforward society-based guidelines, vulnerable eligible patients are very often neither identified nor provided with appropriate treatments to limit the skeletal impact of their cancer therapies.