Abnormal subchondral bone microstructure following steroid administration is involved in the early pathogenesis of steroid-induced osteonecrosis

The Preserved Thickness Ratio of the Femoral Head Contributes to the Collapse Predictor of Osteonecrosis

OBJECTIVES

The collapse of femoral head is a serious symptom of osteonecrosis of the femoral head (ONFH), resulting in hip pain and deformity. However, it is hardly possible to reestablish the femoral head nonoperatively once the collapse happens. Predicting femoral head collapse is of great value for the prognosis of ONFH. This study aimed to develop a new method to quantify the preserved thickness of femoral head and to assess its diagnostic contribution in predicting femoral head collapse on plain radiographs.

METHODS

This was a single-center retrospective study. A total of 101 hips (85 patients) with ARCO stage II from January 2008 to December 2016 were included in this study. The preserved thickness was measured on standard anteroposterior (AP) and frog-leg (FL) radiographs. The anteroposterior view's preserved thickness ratio (APTR) and the frog-leg view's preserved thickness ratio (FPTR) were calculated to show the preserved thickness ratio of the femoral head anteriorly and laterally. Univariate and multivariate logistic regression was performed to determine the risk factors for collapse. Sensitivity, specificity, and cut-off values for APTR and FPTR were determined by the receiver operating characteristic (ROC) curve analysis. Kaplan-Meier (K-M) analysis was applied to determine femoral head survival in ONFH patients.

RESULTS

The mean age of the 27 females and 58 males was 38.93 years old. The mean follow-up time was 74.62 (36-124) months in the non-collapse group and 18.66 (3-82) months in the collapse group. Femoral head collapse was observed in 62 hips during the follow-up period. Logistic regression analysis and ROC results showed that APTR <24.79% and FPTR <10.62% were significantly correlated with femoral head collapse. The Kaplan-Meier survival curve suggested that the overall survival rate of APTR ≥24.79% was 68.2% at 5 and 10 years and FPTR ≥10.62% was 71.63% at 5 and 10 years. At the last follow-up, 26 hips had collapse on the anterior side of the femoral head, 12 hips occurred on the lateral side, and 24 hips happened to collapse on both anterior and lateral sides.

CONCLUSION

Femoral head collapse predominantly occurred anteriorly rather than laterally in ONFH patients. The measurements of APTR and FPTR have noticeable implications for the prediction of femoral head collapse, and contribute to the selection of treatment options for ONFH patients with types B and C1 according to the JIC classification.

What Is New in Stage 3 of the 2019 Revised Association Research Circulation Osseous Staging System of Osteonecrosis of the Femoral Head: A Relationship to Bone Resorption

PURPOSE

The aim of the study is to evaluate the stage 3 findings of the 2019 revision of the Association Research Circulation Osseous (ARCO) staging system for osteonecrosis of the femoral head between 3A and 3B and the relationship with bone resorption area.

MATERIALS AND METHODS

We retrospectively enrolled 87 patients with ARCO stage 3 osteonecrosis of the femoral head, divided into stage 3A (n = 73) and 3B (n = 14). The revised stage 3 findings included subchondral fracture, fracture in necrotic portion, and flattening of the femoral head and were compared between stage 3A and 3B. The association between these findings and the causative features of bone resorption area was also evaluated.

RESULTS

All stage 3 cases had subchondral fractures. In stage 3A, these fractures were generated by crescent sign (41.1%) and by fibrovascular reparative zone in 58.9%; however, in stage 3B, fibrovascular reparative zone generated 92.9% of these fractures and crescent sign only 7.1% with statistical significance ( P = 0.034). Necrotic portion fracture was noted in 36.7% and femoral head flattening was observed in 14.9% of all stage 3. Necrotic portion fracture (92.9% vs 26.0%) and femoral head flattening (71.4% vs 4.1%) were observed more frequently in stage 3B than 3A ( P < 0.001). Almost all subchondral fractures by fibrovascular reparative zone (96.4%) and necrotic portion fracture (96.9%), and all femoral head flattening was presented with bone resorption area with expanding areas.

CONCLUSIONS

The ARCO stage 3 descriptions reflect severity in this order: subchondral fracture, necrotic portion fracture, and femoral head flattening. More severe findings are usually associated with expanding bone resorption areas.

An injectable copolymer of fatty acids (ARA 3000 BETA) as a promising treatment for osteoarthritis

Osteoarthritis (OA) is the most prevalent rheumatic disease and a fast growing cause of disability. Current pharmacological treatments include antalgics and non-steroid anti-inflammatory drugs to control pain and inflammation as well as slow acting drugs such as intra-articular (IA) administration of hyaluronic acid. Oral supplementation or diet rich in polyunsaturated free fatty acids are proposed but evidence for benefit is still under debate. We here investigated the therapeutic potential of ARA 3000 BETA, an injectable copolymer of fatty acids, at the structural level in OA. Collagenase-induced osteoarthritis model was induced in C57BL/6 mice by collagenase injection into knee joint. Mice were treated with one or two IA or four intra-muscular injections (IM) of ARA 3000 BETA. At sacrifice, knee joints were recovered for cartilage analysis by confocal laser scanning microscopy (CLSM) and bone analysis by micro-computed tomography system. OA histological scoring was performed after safranin O/fast green staining. Histological analysis revealed a protective effect against cartilage degradation in treated knee joints after IM and IA administration. This was confirmed by CLSM with a significant improvement of all articular cartilage parameters, including thickness, volume and surface degradation whatever the administration route. A slight protective effect was also noticed on subchondral bone parameters and knee joint calcification after IM administration and to a lesser extent, two IA injections. We demonstrated the therapeutic efficacy of injectable ARA 3000 BETA in OA with a protection against cartilage and bone alterations providing the proof-of-concept that clinical translation might be envisioned to delay disease progression.

Osteonecrosis of Trapezium Occurring in Patient with History of Recurrent Carpometacarpal Corticosteroid Injection

Osteonecrosis affecting the carpal bones is rare and is mostly seen in the lunate (Kienböck's disease). Osteonecrosis of the scaphoid (Preiser disease) is even rarer. There are only four individual case reports published on patients presenting with trapezium necrosis, none with previous history of corticosteroid injection. This case report is the first presentation of isolated trapezial necrosis in the setting of prior corticosteroid injection for thumb basilar arthritis. Level of Evidence: Level V (Therapeutic).

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.

Promotion of osteogenesis by Sweroside via BMP2-involved signaling in postmenopausal osteoporosis

Phlomis umbrosa has been traditionally used for bone diseases in traditional Korean Medicine. Sweroside (SOS), marker compounds of P. umbrosa, has been known to promote osteoblast differentiation. In this study, ameliorative effects of SOS on osteoporosis and potential target pathway were investigated. Ovariectomized mice were administered three doses of SOS three times a week for 4 weeks after inducing osteoporosis. Bone mineral content (BMC) and bone mineral density (BMD) were analyzed by dual energy X-ray absorptiometry. A human osteosarcoma cell line (SaOS-2) was differentiated to clarify the promoting effects of SOS on osteoblast differentiation and bone formation. Osteoblastic bone-forming markers were evaluated in lumbar vertebrae (LV) and mineralized SaOS-2 cells. SOS markedly elevated BMC and BMD levels and attenuated the bone marrow adipocytes in the femoral shaft. SOS increased the formation of bone matrix in SaOS-2 cells. Bone morphogenetic protein-2 (BMP2) and runt-related transcription factor 2 (CBFA1) in LV and SaOS-2 cells were up-regulated by SOS. SOS increased alkaline phosphatase (ALPL), osteopontin (SPP1), and bone sialoprotein-1 (BSPH1). In conclusion, SOS induced the formation of mineralized bone matrix by regulating BMP2/CBFA1-mediated molecules. Therefore, SOS could be a therapeutic compound of treatment for osteoporosis by producing the new bone matrix.

Histopathological and immunohistochemical aspects of bone tissue in aseptic necrosis of the femoral head

Femoral head osteonecrosis, also known as avascular necrosis, is a disease with a multifactorial etiology, characterized by a profound change of bone architecture, which leads to the diminishing of bone resistance and femoral head collapse. The main causes that lead to femoral head necrosis are represented by the decrease of local blood perfusion and increase of intraosseous pressure, because of an excessive development of adipose tissue in the areolas of the trabecular bone tissue in the femoral head. The histopathological and immunohistochemical (IHC) study performed by us showed that most of bone trabeculae were damaged by necrotic-involutive processes, their sizes being reduced, both regarding their length and their diameter; generally, the spans were thin, fragmented, distanced among them, which led to the occurrence of some large areolar cavities, full of conjunctive tissue, rich in adipocytes. Some of the residual bone spans even presented microfractures. In the structure of the trabecular bone tissue, numerous cavities showed lack of content, which indicates the death of osteocytes inside, while the endosteum appeared very thin, with few osteoprogenitor, flattened, difficult to highlight cells. The IHC study showed a low reaction of the bone reparatory processes and a reduced multiplication capacity of bone cells involved in the remodeling and remake of the diseased bone tissue. Nevertheless, there were identified numerous young conjunctive cells (fibroblasts, myofibroblasts), positive to proliferating cell nuclear antigen (PCNA), cells that have a high capacity of multiplication, participating in the formation of a fibrous conjunctive tissue (sclerous) instead of the damaged bone trabeculae. The formation of fibrous conjunctive tissue causes the reduction of mechanical resistance of the femoral head and its collapse. The IHC study of the microvascularization in the femoral head damaged by aseptic osteonecrosis showed the presence of a very low vascular system, both in the residual bone trabeculae and in the sclerous conjunctive tissue. Of the inflammatory cells present in the spongy bone tissue of the femoral head affected by osteonecrosis, the most numerous ones were the macrophages. Both macrophages and T- and B-lymphocytes had a heterogenous distribution.

Dose-related histopathology and bone remodeling characteristics of the knee articular cartilage and subchondral bone induced by glucocorticoids in rats

The aim of the current study was to investigate histopathological changes and bone remodeling in the knee articular cartilage and subchondral bone in rats following treatment with glucocorticoids. A total of 30 3-month-old female Sprague-Dawley rats were randomly divided into either a vehicle control group or one of three experimental groups wherein dexamethasone (Dex) was administered at a dose of 1.0, 2.5 or 5.0 mg/kg (Dex1.0, Dex2.5 and Dex5.0, respectively), for 8 weeks. Articular cartilage and the epiphyseal subchondral bone of the proximal tibias were evaluated by histopathology or for bone remodeling using histomorphometry. No histological changes were identified in the knee articular cartilage but the bone formation rate of the subchondral bone was lower in the Dex1.0 group compared with that of the control group. Compared with the control and the Dex1.0 group, the width of the articular cartilage and the subchondral plate were larger, with abnormal morphology and increased apoptosis of chondrocytes, decreased cell/matrix volume ratio in the cartilage and fewer blood vessels in the subchondral plate in the Dex2.5 and Dex5.0 groups. A higher Dex dose resulted in more severe inhibition of bone formation, a greater number of apoptotic osteocytes and constrained bone resorption. All microstructure parameters indicated no significant changes in the Dex2.5 group but exhibited deterioration in the Dex5.0 group compared with the normal and Dex1.0 group. There were no significant differences in morphological changes, or in static and dynamic bone indices between the Dex2.5 and Dex5.0 groups. In conclusion, long-term glucocorticoid use induced dose-related histopathological changes in the knee articular cartilage, along with unbalanced bone remodeling and osteopenia in the subchondral bone. The degree of damage to the articular cartilage was milder and transformed from compensation to degeneration at higher doses.

Screening of Serum Protein Markers for Avascular Osteonecrosis of Femoral Head Differentially Expressed after Treatment with Yuanshi Shengmai Chenggu Tablets

Avascular necrosis of the femoral head (ANFH) is an a frequently occurring orthopaedic disease with high morbidity. Traditional Chinese Medicine (TCM) Yuanshi Shengmai Chenggu Tablet is a valid prescription for treating steroid-induced femoral head necrosis. However, there are rare investigations about the serum protein marker expression after the acting of drugs on hormone and TCM. In the present study, we aimed to systematically discover and validate the serum biomarkers expression difference in patients with steroid-induced avascular necrosis of femoral head (SANFH) after taking Yuanshi Shengmai Chenggu Tablets (SANFH-TCM), so as to reveal the action mechanism of TCM from the molecular level by using isobaric tags for relative and absolute quantification (iTRAQ) with multiple reaction monitoring quantification. Significant differences in fibrinogen alpha, fibrinogen beta, fibrinogen gamma, fibronectin, C-reactive protein, apolipoprotein A, apolipoprotein D, and apolipoprotein E were found among SANFH, SANFH-TCM, and healthy controls. Therefore, our study proposes potential biomarkers for SANFH diagnosis and for the prognosis of femoral head necrosis after Traditional Chinese Medicine treatment.

Predicting the collapse of the femoral head due to osteonecrosis: From basic methods to application prospects

Collapse of the femoral head is the most significant pathogenic complication arising from osteonecrosis of the femoral head. It is related to the disruption of the maintenance of cartilage and bone, and results in an impaired function of the vascular component. A method for predicting the collapse of the femoral head can be treated as a type of clinical index. Efforts in recent years to predict the collapse of the femoral head due to osteonecrosis include multiple methods of radiographic analysis, stress distribution analysis, finite element analysis, and other innovative methods. Prediction methods for osteonecrosis of the femoral head complications originated in Western countries and have been further developed in Asia. Presently, an increasing number of surgeons have chosen to focus on surgical treatments instead of prediction methods to guide more conservative interventions, resulting in a growing reliance on the more prevalent and highly effective total hip arthroplasty, rather than on more conservative treatments. In this review, we performed a literature search of PubMed and Embase using search terms including "osteonecrosis of femoral head," "prediction," "collapse," "finite element," "radiographic images," and "stress analysis," exploring the basic prediction method and prospects for new applications.

Salvianolic acid B prevents steroid-induced osteonecrosis of the femoral head via PPARγ expression in rats

Salvianolic acid B (Sal B) is a water-soluble phenolic compound derived from Salvia Miltiorrhiza. Recent studies show Sal B has a clear function of anti-cerebral ischemia injury, which is closely related to antioxidation, free radical scavenging, neuroprotection and the blood brain barrier. The aim of the present study was to verify whether Sal B prevents steroid-induced osteonecrosis of the femoral head and to investigate its underlying pharmacological mechanisms. Steroid-induced osteonecrosis rat models were established to evaluate the effects of Sal B on osteonecrotic changes and repair processes. The use of Sal B improved steroid-induced histopathological scores and inhibited osteoclast differentiation in rats. Notably, Sal B induced bone marrow-derived mesenchymal stem cells into osteogenesis. Moreover, Sal B treatment suppressed peroxisome proliferator-activated receptor (PPAR)γ and AP2 protein expression levels and increased runt-related transcription factor 2 and Collagen I protein expression levels in steroid-induced rats. osteocalcin and alkaline phosphatase content in steroid-induced rats was enhanced by treatment with Sal B. These results suggest that Sal B prevents steroid-induced osteonecrosis of the femoral head via PPARγ expression in rats. The present pilot study provides a brief insight into the effect of Sal B on steroid-induced osteonecrosis.