Canonical pathways for validating steroid-associated osteonecrosis in mice

The present study aimed to establish and evaluate a preclinical model of steroid-associated osteonecrosis (SAON) in mice. Sixteen 24-week-old male C57BL/6 mice were used to establish SAON by two intraperitoneal injections of lipopolysaccharide (LPS), followed by three subcutaneous injections of methylprednisolone (MPS). Each injection was conducted on working day, with an interval of 24 h. Six cycles of injections were conducted. Additional twelve mice (age- and gender-matched) were used as normal controls. At 2 and 6 weeks after completing induction, bilateral femora and bilateral tibiae were collected for histological examination, micro-CT scanning, and bulk RNA sequencing. All mice were alive until sacrificed at the indicated time points. The typical SAON lesion was identified by histological evaluation at week 2 and week 6 with increased lacunae and TUNEL+ osteocytes. Micro-CT showed significant bone degeneration at week 6 in SAON model. Histology and histomorphometry showed significantly lower Runx2+ area, mineralizing surface (MS/BS), mineral apposition rate (MAR), bone formation rate (BFR/BS), type H vessels, Ki67+ (proliferating) cells, and higher marrow fat fraction, osteoclast number and TNFα+ areas in SAON group. Bulk RNA-seq revealed changed canonical signaling pathways regulating cell cycle, angiogenesis, osteogenesis, and osteoclastogenesis in the SAON group. The present study successfully established SAON in mice with a combination treatment of LPS and MPS, which could be considered a reliable and reproducible animal model to study the pathophysiology and molecular mechanism of early-stage SAON and to develop potential therapeutic approaches for the prevention and treatment of SAON.

Selenium nanoparticles/carboxymethyl chitosan/alginate antioxidant hydrogel for treating steroid-induced osteonecrosis of the femoral head

Oxidative stress plays a crucial role in steroid-induced osteonecrosis of the femoral head (SONFH). Although several antioxidant strategies have been investigated for treating SONFH, their antioxidant efficiencies and therapeutic effects remain unsatisfactory. Here, we developed a selenium nanoparticles/carboxymethyl chitosan/alginate (SeNPs/CMC/Alg) antioxidant hydrogel and evaluated its ability to treat SONFH. In vitro assays indicated that the SeNPs/CMC/Alg hydrogel exhibited excellent properties, such as low cytotoxicity, sustained SeNPs release, and favorable antioxidant activity. Under oxidative stress, the SeNPs/CMC/Alg hydrogel promoted reactive oxygen species (ROS) elimination and enhanced the osteogenic and proangiogenic abilities of bone marrow mesenchymal stem cells (BMSCs). After establishing a rabbit model of SONFH, the SeNPs/CMC/Alg hydrogel was transplanted into the femoral head after core decompression (CD) surgery. Radiographic and histological analyses revealed that the hydrogel treatment alleviated SONFH by eliminating ROS and promoting osteogenesis and angiogenesis compared to those in the CD and CMC/Alg groups. In vitro and in vivo studies indicated that the Wnt/β-catenin signaling pathway was activated by the SeNPs/CMC/Alg hydrogel in both hydrogen peroxide-conditioned BMSCs and necrotic femoral heads. These findings indicate that local transplantation of the SeNPs/CMC/Alg hydrogel is beneficial for treating SONFH, as it promotes ROS elimination and activation of the Wnt/β-catenin signaling pathway.

Echinacoside alleviates glucocorticoid induce osteonecrosis of femoral head in rats through PI3K/AKT/FOXO1 pathway

Steroid-induced osteonecrosis of the femoral head (SONFH), caused by glucocorticoid (GC) administration, is known to exhibit a high incidence worldwide. Although osteoblast apoptosis has been reported as an important cytological basis of SONFH, the precise mechanism remains elusive. Echinacoside (Ech), a natural phenylethanoid glycoside, exerts multiple beneficial effects, such as facilitation of cell proliferation and anti-inflammatory and anticancer activities. Herein, we aimed to explore the regulatory mechanism underlying glucocorticoid-induced osteoblast apoptosis and determine the protective efficacy of Ech against SONFH. We comprehensively surveyed multiple public databases to identify SONFH-related genes. Using bioinformatics analysis, we identified that the PI3K/AKT/FOXO1 signaling pathway was most strongly associated with SONFH. We examined the protective effect of Ech against SONFH using in vivo and in vitro experiments. Specifically, dexamethasone (Dex) decreased p-PI3K and p-AKT levels, which were reversed following Ech addition. Validation of the PI3K inhibitor (LY294002) and molecular docking of Ech and PI3K/AKT further indicated that Ech could directly enhance PI3K/AKT activity to alleviate Dex-induced inhibition. Interestingly, Dex upregulated the expression of FOXO1, Bax, cleaved-caspase-9, and cleaved-caspase-3 and enhanced MC3T3-E1 apoptosis; application of Ech and siRNA-FOXO1 reversed these effects. In vitro, Ech decreased the number of empty osteocytic lacunae, reduced TUNEL and FOXO1 positive cells, and improved bone microarchitecture. Our results provide robust evidence that PI3K/AKT/FOXO1 plays a crucial role in the development of SONFH. Moreover, Ech may be a promising candidate drug for the treatment of SONFH.

n-3 PUFAs Show Promise as Adjuvants in Chemotherapy, Enhancing their Efficacy while Safeguarding Hematopoiesis and Promoting Bone Generation

Cancer ranks as the second leading cause of mortality in high-income countries, underscoring the critical need for effective therapeutic strategies. One prominent approach, chemotherapy, is widely employed for treating solid tumors. However, the significant adverse effects associated with chemotherapy, notably myeloablation and osteonecrosis, impart considerable challenges by compromising immune function and diminishing patients' quality of life. Furthermore, the emergence of chemotherapy resistance poses a formidable hurdle in achieving successful cancer treatment outcomes. In this context, the focus is on exploring alternative approaches to enhance the efficacy of cancer treatment and mitigate its adverse consequences. Among these approaches, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), two n-3 polyunsaturated fatty acids (PUFAs), have garnered substantial interest. These PUFAs exhibit the potential to influence membrane lipid composition and modulate critical gene expressions associated with cancer, such as Bcl-2, PI3K, NF-κB, and phosphorylated Akt, thereby potentially reducing cancer risk. Moreover, emerging evidence highlights their ability to augment chemotherapy efficacy, particularly in drug-resistant cancer cells. Importantly, both preclinical and clinical investigations have provided compelling evidence supporting the protective effects of n-3 PUFAs on healthy cells. Leveraging these findings, there has been growing attention on the exploration of n-3 PUFAs as adjuvants to chemotherapy. This strategic approach holds promise in mitigating the adverse effects linked to chemotherapy, notably myeloablation and osteonecrosis, while simultaneously enhancing its effectiveness in combating cancer. This comprehensive review delves into the multifaceted attributes of n-3 PUFAs, encompassing their cytotoxic properties, potential as chemopreventive agents, and their prospective role in ameliorating the adverse effects commonly associated with chemotherapy, with a particular emphasis on myeloablation and osteonecrosis. By elucidating the intricate interplay between n-3 PUFAs and cancer treatment paradigms, this review contributes to the expanding body of knowledge aimed at refining cancer therapeutic strategies and enhancing patient outcomes.

Taxifolin-mediated Nrf2 activation ameliorates oxidative stress and apoptosis for the treatment of glucocorticoid-induced osteonecrosis of the femoral head

Glucocorticoid-induced osteonecrosis of the femoral head (GIONFH) is the main complication secondary to long-term or excessive use of glucocorticoids (GCs). Taxifolin (TAX) is a natural antioxidant with various pharmacological effects, such as antioxidative stress and antiapoptotic properties. The purpose of this study was to explore whether TAX could regulate oxidative stress and apoptosis in GIONFH by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. We conducted qRT-PCR, Western blotting, TUNEL assays, flow cytometry, and other experiments in vitro. Microcomputed tomography analysis, hematoxylin-eosin staining, and immunohistochemical staining were performed to determine the therapeutic effect of TAX in vivo. TAX mitigated the overexpression of ROS and NOX gene expression induced by DEX, effectively reducing oxidative stress. Additionally, TAX could alleviate DEX-induced osteoblast apoptosis, as evidenced by qRT-PCR, Western blotting, and other experimental techniques. Our in vivo studies further demonstrated that TAX mitigates the progression of GIONFH in rats by combating oxidative stress and apoptosis. Mechanistic exploration revealed that TAX thwarts the progression of GIONFH through the activation of the Nrf2 pathway. Overall, our research herein reports that TAX-mediated Nrf2 activation ameliorates oxidative stress and apoptosis for the treatment of GIONFH.

Cyasterone has a protective effect on steroid-induced Osteonecrosis of the femoral head

CONTEXT

Cyasterone alleviated the apoptosis of BMSCs induced by Dexamethasone via the PI3K/AKT signaling pathway. In addition, Cyasterone had a protective effect on SIONFH model rats by reducing the percentage of empty bone lacunae.

OBJECTIVE

To study the effect of Cyasterone on apoptosis of rat BMSCs and its function on the SIONFH rat model.

METHODS

Rat BMSCs were cultured and divided into Control, DXM and Cyasterone (DXM+Cyasterone) groups. The apoptosis of each group was detected by flow cytometry, the expressions of Caspase-3 and Caspase-9 were detected by immunofluorescence staining, and the mRNA and protein expressions of AKT, BAX, P53, P85, Bcl-2 and Cytochrome C were detected by qPCR and WB. In animal experiments, the femoral head of rats were subjected to HE staining and Micro-CT to observe the necrosis and repair conditions.

RESULTS

The apoptosis rate of DXM and Cyasterone groups increased compared with Control group, and the apoptosis rate of Cyasterone group decreased compared with DXM group. Compared with DXM group, the mRNA expression of BAX, P53, P85 and Cytochrome C in Cyasterone group were increased, while the protein expression of AKT and Bcl-2 decreased. The histopathological and morphological analysis showed that Cyasterone promoted the trabecular bone structure in rat, which evenly benefit for the repair of SIONFH.

CONCLUSION

Cyasterone can reduce the apoptosis of rat BMSCs induced by Dexamethasone, and help promoting the bone repair in SIONFH rats.

Menaquinone-4 prevents medication-related osteonecrosis of the jaw through the SIRT1 signaling-mediated inhibition of cellular metabolic stresses-induced osteoblast apoptosis

Long-term usage of bisphosphonates, especially zoledronic acid (ZA), induces osteogenesis disorders and medication-related osteonecrosis of the jaw (MRONJ) in patients, thereby contributing to the destruction of bone remodeling and the continuous progression of osteonecrosis. Menaquinone-4 (MK-4), a specific vitamin K2 isoform converted by the mevalonate (MVA) pathway in vivo, exerts the promotion of bone formation, whereas ZA administration suppresses this pathway and results in endogenous MK-4 deficiency. However, no study has evaluated whether exogenous MK-4 supplementation can prevent ZA-induced MRONJ. Here we showed that MK-4 pretreatment partially ameliorated mucosal nonunion and bone sequestration among ZA-treated MRONJ mouse models. Moreover, MK-4 promoted bone regeneration and inhibited osteoblast apoptosis in vivo. Consistently, MK-4 downregulated ZA-induced osteoblast apoptosis in MC3T3-E1 cells and suppressed the levels of cellular metabolic stresses, including oxidative stress, endoplasmic reticulum stress, mitochondrial dysfunction, and DNA damage, which were accompanied by elevated sirtuin 1 (SIRT1) expression. Notably, EX527, an inhibitor of the SIRT1 signaling pathway, abolished the inhibitory effects of MK-4 on ZA-induced cell metabolic stresses and osteoblast damage. Combined with experimental evidences from MRONJ mouse models and MC3T3-E1 cells, our findings suggested that MK-4 prevents ZA-induced MRONJ by inhibiting osteoblast apoptosis through suppression of cellular metabolic stresses in a SIRT1-dependent manner. The results provide a novel translational direction for the clinical application of MK-4 for preventing MRONJ.

Alpha-lipoic acid could be a promising treatment in steroid-induced osteonecrosis

OBJECTIVE

Glucocorticoid-induced osteonecrosis is a serious debilitating health problem. In the present study, we investigated the effects of alpha-lipoic acid on glucocorticoid-induced osteonecrosis in rats.

MATERIALS AND METHODS

A total of 40 male Wistar albino rats were equally assigned to 4 groups as control, methylprednisolone acetate (MPA), alpha-lipoic acid (ALA), and methylprednisolone acetate with alpha-lipoic acid (MPA+ALA). The animals in MPA group subcutaneously received 15 mg/kg/week for 2 weeks, whereas 100 mg/kg/day alpha-lipoic acid was intraperitoneal administered for 4 weeks to ALA group. The MPA+ALA group was subjected to both treatments in same doses. Osteonecrosis was confirmed and graded histologically. The serum concentrations of glucose, total cholesterol, low- and high-density lipoprotein, triglyceride, as well as the total oxidant and antioxidant status, oxidative stress index, prothrombin time and activated partial thromboplastin time were evaluated. Also, lipid peroxidation and DNA damage were immunohistochemically assessed in the bone.

RESULTS

Osteonecrotic lesions were narrower in the MPA+ALA group than in the MPA group (p<0.05). As compared to the controls, the biochemical parameters in MPA and MPA+ALA groups were significantly increased (p<0.001). The oxidative stress index was significantly higher in the groups with MPA than the controls (p=0.002), but the animals treated with ALA alongside MPA displayed lesser scores than the ones injected with solely MPA (p=0.03). The administration of MPA elevated lipid peroxidation and DNA damage, which were successfully alleviated by ALA.

CONCLUSIONS

Alpha-lipoic acid may be suggested to be a protective supplement in glucocorticoid-induced osteonecrosis in rats. The antioxidant capacity of alpha-lipoic acid may involve its beneficial effects.

Inhibition of HMGB1/RAGE Signaling Reduces the Incidence of Medication-Related Osteonecrosis of the Jaw (MRONJ) in Mice

Medication-related osteonecrosis of the jaw (MRONJ) is a severe complication of antiresorptive or antiangiogenic medications, used in the treatment of bone malignancy or osteoporosis. Bone necrosis, mainly represented by osteocytic death, is always present in MRONJ sites; however, the role of osteocyte death in MRONJ pathogenesis is unknown. High mobility group box 1 (HMGB1) is a non-histone nucleoprotein that in its acetylated form accumulates in the cytoplasm, whereas non-acetylated HMGB1 localizes in the nucleus. SIRT1 deacetylase regulates cellular localization of HMGB1. Interestingly, HMGB1 is released during cell necrosis and promotes inflammation through signaling cascades, including activation of the RAGE receptor. Here, we utilized a well-established mouse MRONJ model that utilizes ligature-induced experimental periodontitis (EP) and treatment with either vehicle or zolendronic acid (ZA). Initially, we evaluated HMGB1-SIRT1 expression in osteocytes at 1, 2, and 4 weeks of treatment. Significantly increased cytoplasmic and perilacunar HMGB1 expression was observed at EP sites of ZA versus vehicle (Veh) animals at all time points. SIRT1 colocalized with cytoplasmic HMGB1 and presented a statistically significant increased expression at the EP sites of ZA animals for all time points. RAGE expression was significantly higher in the submucosal tissues EP sites of ZA animals compared with those in vehicle group. To explore the significance of increased cytoplasmic and extracellular HMGB1 and increased RAGE expression in MRONJ pathogenesis, we used pharmacologic inhibitors of these molecules. Combined HMGB1/RAGE inhibition resulted in lower MRONJ incidence with statistically significant decrease in osteonecrotic areas and bone exposure versus non-inhibitor treated ZA animals. Together, our data point to the role of HMGB1 as a central alarmin, overexpressed at early phase of MRONJ pathogenesis during osteocytic death. Moreover, HMGB1-RAGE pathway may represent a new promising therapeutic target in patients at high risk of MRONJ. © 2022 American Society for Bone and Mineral Research (ASBMR).

Secondary osteonecrosis of the knee as a part of long COVID-19 syndrome: a case series

COVID-19 infection affects different organ systems with long-term sequelae, which has been termed as long COVID-19 syndrome. To the best of our knowledge, osteonecrosis of the knee as a part of long COVID-19 syndrome has not been documented. Corticosteroids are being used extensively in moderate and severe cases of COVID-19. We report two cases who developed osteonecrosis of the knee after being treated for COVID-19 infection. In our case series, the mean cumulative dose of prednisolone was 1156.5 mg (900-1413 mg), which is less than the cumulative dose reported in literature for osteonecrosis of the knee. In our case series, the patients developed symptomatic osteonecrosis at a mean interval of 73 days after initiation of steroid therapy, with the earliest presenting at 25 days. Early diagnosis of osteonecrosis of the knee on high clinical suspicion by MRI would help in early intervention with bisphosphonate therapy.

Bone Targeting Agents in Patients with Prostate Cancer: General Toxicities and Osteonecrosis of the Jaw

Introduction: Bone metastases are the most frequent site of secondary localization of prostate cancer (PCa) and are present in about 90% of cases of advanced disease. Consequently, an adequate management of bone involvement is of pivotal importance in the therapeutic approach and skeletal-related events (SREs) need to be closely monitored and promptly assessed and treated. Bone targeting agents (BTAs), consisting in bisphosphonates and denosumab, are an essential part of the treatment of metastatic prostate cancer that accompanies systemic treatments throughout the most part of the history of the disease. Activity and safety of bone targeting agents: These treatments are correlated to better outcomes in terms of reduction of SREs and, in metastatic castration resistant setting, of increased overall survival (OS), but several important adverse events have to be managed and prevented. Of these, osteonecrosis of the jaw (ONJ) is extremely invalidating and should be managed with a special attention. Discussion: The role of BTAs in prostate cancer is pivotal throughout many stages of the disease, but several toxicities should be quickly recognized and treated. We aim at recollecting evidence on clinical benefit of BTAs, common and specific toxicities, and explore the pathophysiology and clinical aspects of osteonecrosis of the jaw. We present a review of the literature to report the role of the different types of bone targeting agents in the management of prostate cancer with bone metastases with a particular focus on common toxicities and ONJ to recollect current evidences on the activity of these compounds and the correct management of their adverse events.

Regeneration of Bone Defects in a Rabbit Femoral Osteonecrosis Model Using 3D-Printed Poly (Epsilon-Caprolactone)/Nanoparticulate Willemite Composite Scaffolds

Steroid-associated osteonecrosis (SAON) is a chronic disease that leads to the destruction and collapse of bone near the joint that is subjected to weight bearing, ultimately resulting in a loss of hip and knee function. Zn2+ ions, as an essential trace element, have functional roles in improving the immunophysiological cellular environment, accelerating bone regeneration, and inhibiting biofilm formation. In this study, we reconstruct SAON lesions with a three-dimensional (3D)-a printed composite made of poly (epsilon-caprolactone) (PCL) and nanoparticulate Willemite (npW). Rabbit bone marrow stem cells were used to evaluate the cytocompatibility and osteogenic differentiation capability of the PCL/npW composite scaffolds. The 2-month bone regeneration was assessed by a Micro-computed tomography (micro-CT) scan and the expression of bone regeneration proteins by Western blot. Compared with the neat PCL group, PCL/npW scaffolds exhibited significantly increased cytocompatibility and osteogenic activity. This finding reveals a new concept for the design of a 3D-printed PCL/npW composite-based bone substitute for the early treatment of osteonecrosis defects.

Bisphosphonate Therapy for Treating Osteonecrosis in Pediatric Leukemia Patients: A Systematic Review

BACKGROUND

Despite improved outcomes in children with leukemia, complications such as osteonecrosis are common. We conducted a systematic review to investigate the role of bisphosphonates in reducing pain, improving mobility, and stabilizing lesions in pediatric leukemia survivors.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we searched the PubMed, Embase, Cochrane, Web of Science, Scopus, CINAHL, and ClinicalTrials.gov databases. Five of 221 articles retrieved met our inclusion criteria.

RESULTS

Bisphosphonates, especially when combined with dietary calcium and vitamin D supplements and physical therapy (supplements/PT) were associated with improved pain and mobility in 54% and 50% of patients, respectively. A significantly greater proportion of patients treated with bisphosphonates (83%) reported mild/moderate pain or no pain compared with those with supplements/PT alone (36%) (P<0.001). Sixty-six percent of patients treated with bisphosphonates achieved improved/full mobility compared with 27% of those treated with supplements/PT alone (P=0.02). However, 46% of patients showed progressive joint destruction despite bisphosphonate therapy. No adverse events were reported, except for acute phase reactions to intravenous therapies.

CONCLUSIONS

Bisphosphonates, when combined with supplements/PT, were associated with less pain and improved mobility, but not prevention of joint destruction in pediatric leukemia patients with osteonecrosis.

Juvenile-onset multifocal osteonecrosis in systemic lupus erythematosus: A case report

RATIONALE

Osteonecrosis (ON) is a devastating illness that leads to bone ischemia and potential joint destruction. Systemic lupus erythematosus (SLE) is a chronic, autoimmune disease, with multi-system involvement which is closely associated with occurrence of ON. Multifocal ON, with an estimated morbidity of 3% in SLE patients, is extremely rare in juvenile subjects.

PATIENT CONCERNS

A 13.3-year-old female SLE patient was admitted to hospital 20 months following the SLE diagnosis because of a sudden aggravation of sore knees. She suffered from double knee joint pain and her left knee joint showed typical signs of inflammation including redness, swelling, heat, and pain.

DIAGNOSES

The SLE patient was diagnosed with multifocal ON of her knee joint based on magnetic resonance imaging findings of bone destruction and osteoproliferation at the bilateral distal femur and proximal tibia.

INTERVENTIONS

The patient received high-dose methylprednisolone and intravenous cyclophosphamide pulse therapies for controlling active lupus and nephritis. Oral calcitriol and dipyridamole were administered to alleviate knee pain and inhibit thrombi formation, thereby suppressing ON progress.

OUTCOMES

Three weeks following the treatment, the swelling in patient's left knee subsided. Her self-reporting pain score decreased from 9 to 4 and walking time increased from 45minutes to 90minutes per day. Nearly 5 weeks later, the pain in bilateral knee joints disappeared and the patient could walk without difficulties.

LESSONS

This patient is the youngest SLE patient who developed multifocal ON based on the reported literature. It suggests that ON can occur in young SLE patients. A combination of internal and external risk factors can promote the development of ON. The balanced approach to the application of corticosteroids and immunosuppressors in the treatment of SLE and prevention of ON is a challenging problem that deserves further exploration.

Bisphosphonate for spontaneous osteonecrosis of the knee: A protocol for systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Bisphosphonates are commonly used to treat spontaneous osteonecrosis of the knee (SONK), while there are no relevant systematic review or meta-analysis designed to evaluate the effects of bisphosphonates on SONK.

METHODS

We will identify relevant randomized controlled trials from the PubMed, EMBASE, CINAHL and China National Knowledge Infrastructure, up to March 20, 2020. Data that meets the inclusion criteria will be extracted and analyzed using RevMan V.5.3 software. Two reviewers will assess quality of the included studies by using the Cochrane Collaboration risk of bias tool. Egger test and Begg test will be used to evaluate publication bias. And Grading of Recommendations Assessment, Development and Evaluation will be employed to assess the quality of evidence.

RESULTS

In this study, we will analyze the effect of bisphosphonates on pain intensity, physical function, biochemical including alkaline phosphatase, N-terminal propeptide of type I procollagen, and C-terminal type I collagen telopeptide, radiological outcome (evaluated by using Magnetic resonance imaging) and ratio of secondary surgery for patients with SONK.

CONCLUSION

Our findings will provide evidence for the effectiveness and potential treatment prescriptions of bisphosphonates acupuncture for patients affected by SONK.

The rule of hydrogen peroxide long term rinse during a particular alveolar bone healing after ONJ injuries in a patient with periodontal disease: a 4-year radiological follow up report of a mental nerve emergence migration

Bisphosphonate Related Osteonecrosis of the Jaw (BRONJ) is a pathology initially described in the early 2000s that has become increasingly common in clinical dentistry and maxillofacial practice due to the frequent use of bisphosphonates medical drugs (BPs) to treat various diseases such as osteoporosis, Paget's syndrome, osteomyelitis and in bone metastases secondary to tumors. Supragingival irrigation applied as monotherapy and in combination with root planning or BFs related bone necrosectomy revealed that supragingival irrigation with a variety of agents reduced the gingival microbial load and gingival inflammation. In this 4-year follow-up study we analyze the use of hydrogen peroxide (H2O2) as an antimicrobial agent for maintenance periodontal health, improving the longevity of teeth and oral cavity healing process.

Do Bisphosphonates Alleviate Pain in Children? A Systematic Review

PURPOSE OF REVIEW

The goal of this systematic review is to analyze the effectiveness of bisphosphonates (BPs) to treat bone pain in children and adolescents who have diseases with skeletal involvement.

RECENT FINDINGS

We included 24 studies (2 randomized controlled trials, 3 non-randomized controlled trials, 10 non-randomized open-label uncontrolled studies, 8 retrospective studies, and 1 study with design not specified). The majority of included studies assessed pain from a unidimensional approach, with pain intensity the most frequently evaluated dimension. Only 38% of studies used validated tools; visual analogue scale was the most frequently employed. BPs were used to alleviate bone pain in a wide variety of pediatrics conditions such as osteogenesis imperfecta, secondary osteoporosis, osteonecrosis related to chemotherapy, chronic non-bacterial osteitis, idiopathic juvenile osteoporosis, unresectable benign bone tumor, and cancer-related pain. Twenty of the 24 studies reported a positive effect of BPs for alleviating pain in different pathologies, but 58% of the studies were categorized as having high risk of bias. Intravenous BPs are helpful in alleviating bone pain in children and adolescents. It is advised that our results be interpreted with caution due to the heterogeneity of the doses used, duration of treatments, and types of pathologies included. In addition, this review shows the paucity of high-quality evidence in the available literature and further research is needed.

TRIAL REGISTRATION

Before the completion of this review, the protocol was registered to PROSPERO (International prospective register of systematic reviews), PROSPERO 2020 ID # CRD42020158316. Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020158316.

Bilateral Kienböck's disease concomitant with gouty arthritis

A 38-year-old man presented with a 2-month history of pain and stiffness in the bilateral wrist. The pain in right wrist was disabling and severe enough to restrict the daily life activities. After the evaluation of clinical and radiological features, the patient was diagnosed with Kienböck's disease Lichtman stage IIIB in the right wrist and stage IIIA in the left wrist. Routine laboratory investigations revealed a serum uric acid 9.27 mg/dL. Lunate excision and scaphocapitate fusion were done in the right wrist after discussing with the patient. The histopathological examinations of tophi in synovial tissue were negatively birefringent under polarised light microscopy. It confirmed the diagnoses of gout. Febuxostat was started postoperatively. The patient returned to work at the end of 5 months. There was no recurrence of symptoms and radiological signs of arthritis at the end of 1 year.

Treatment of spontaneous osteonecrosis of the knee by daily teriparatide: A report of 3 cases

RATIONALE

Although the treatment of femoral head necrosis has already been established with the adoption of daily teriparatide, a clear consensus on the treatment of spontaneous osteonecrosis of the knee (SONK) has yet to be reached. Therefore, we focused on the treatment of SONK with daily teriparatide administration (20 μg, subcutaneous) and confirmed its effects to determine whether it is a valid option.

PATIENTS' CONCERNS

Three osteoporotic patients who were diagnosed with SONK complained of knee pain.

DIAGNOSIS

SONK was diagnosed on magnetic resonance imaging in all cases.

INTERVENTIONS

All patients took daily teriparatide as a treatment for SONK.

OUTCOMES

There was a significant and dramatic reduction in the visual analog scale score 1 month after treatment. After 6 months of treatment, the sizes of the affected SONK lesions were smaller than in the initial phase, and plain X-rays showed no further signs of progression.

LESSONS

Daily teriparatide might be an effective treatment for SONK.

5-Azacytidine and trichostatin A enhance the osteogenic differentiation of bone marrow mesenchymal stem cells isolated from steroid-induced avascular necrosis of the femoral head in rabbit

Bone marrow mesenchymal stem cells (BMSCs) play an important role in the process of bone repair. The present study investigated the effect of 5-azacytidine (AZA) and trichostatin A (TSA) on BMSC behaviors in vitro. The role of WNT family member 5A (WNT5A)/WNT family member 5A (WNT7A)/beta-catenin signaling was also investigated. BMSCs were isolated from a steroid-induced avascular necrosis of the femoral head (SANFH) rabbit model. The third-generation of BMSCs was used after identification. The results revealed obvious degeneration and necrosis in the SANFH rabbit model. AZA, TSA and TSA + AZA increased BMSC proliferation in a time-dependent fashion. AZA, TSA and TSA + AZA induced the cell cycle release from the G0/G1 phase and inhibited apoptosis in BMSCs. AZA, TSA and TSA + AZA treatment significantly decreased caspase-3 and caspase-9 activities. The treatment obviously increased the activity and relative mRNA expression of alkaline phosphatase. The treatment also significantly up-regulated the proteins associated with osteogenic differentiation, including osteocalcin and runt-related transcription factor 2 (RUNX2), and Wnt/beta-catenin signal transduction pathway-related proteins beta-catenin, WNT5A and WNT7A. The relative levels of Dickkopf-related protein 1 (an inhibitor of the canonical Wnt pathway) decreased remarkably. Notably, TSA + AZA treatment exhibited a stronger adjustment ability than either single treatment. Collectively, the present studies suggest that AZA, TSA and TSA + AZA promote cell proliferation and osteogenic differentiation in BMSCs, and these effects are potentially achieved via upregulation of WNT5A/WNT7A/b-catenin signaling.

Rescue bisphosphonate treatment of alveolar bone improves extraction socket healing and reduces osteonecrosis in zoledronate-treated mice

Bisphosphonate (BP)-related osteonecrosis of the jaw, previously known as BRONJ, now referred to more broadly as medication-related osteonecrosis of the jaw (MRONJ), is a morbid condition that represents a significant risk for oncology patients who have received high dose intravenous (IV) infusion of a potent nitrogen containing BP (N-BP) drug. At present, no clinical procedure is available to prevent or effectively treat MRONJ. Although the pathophysiological basis is not yet fully understood, legacy adsorbed N-BP in jawbone has been proposed to be associated with BRONJ by one or more mechanisms. We hypothesized that removal of the pre-adsorbed N-BP drug common to these pathological mechanisms from alveolar bone could be an effective preventative/therapeutic strategy. This study demonstrates that fluorescently labeled BP pre-adsorbed on the surface of murine maxillo-cranial bone in vivo can be displaced by subsequent application of other BPs. We previously described rodent BRONJ models involving the combination of N-BP treatment such as zoledronate (ZOL) and dental initiating factors such as tooth extraction. We further refined our mouse model by using gel food during the first 7 days of the tooth extraction wound healing period, which decreased confounding food pellet impaction problems in the open boney socket. This refined mouse model does not manifest BRONJ-like severe jawbone exposure, but development of osteonecrosis around the extraction socket and chronic gingival inflammation are clearly exhibited. In this study, we examined the effect of benign BP displacement of legacy N-BP on tooth extraction wound healing in the in vivo model. Systemic IV administration of a low potency BP (lpBP: defined as inactive at 100 μM in a standard protein anti-prenylation assay) did not significantly attenuate jawbone osteonecrosis. We then developed an intra-oral formulation of lpBP, which when injected into the gingiva adjacent to the tooth prior to extraction, dramatically reduced the osteocyte necrosis area. Furthermore, the tooth extraction wound healing pattern was normalized, as evidenced by timely closure of oral soft tissue without epithelial hyperplasia, significantly reduced gingival inflammation and increased new bone filling in the extraction socket. Our results are consistent with the hypothesis that local application of a rescue BP prior to dental surgery can decrease the amount of a legacy N-BP drug in proximate jawbone surfaces below the threshold that promotes osteocyte necrosis. This observation should provide a conceptual basis for a novel strategy to improve socket healing in patients treated with BPs while preserving therapeutic benefit from anti-resorptive N-BP drug in vertebral and appendicular bones.

Uncommon presentation of medication-related osteonecrosis of the mandible in a patient with metastatic prostate cancer

An 82-year-old man with a background of prostate carcinoma and bony metastases presented with bilateral discharging neck fistulae. Two years prior to presentation, the patient had been treated with intravenous zoledronic acid for 1 year as part of chemotherapy. Intraoral examination revealed extensive bilateral medication-related osteonecrosis, with orocutaneous fistulae within the neck. Treatment comprised removal of loose necrotic bone sequestrae, debridement of the fistulae and long-term administration of antibiotics, vitamin E and pentoxifylline. Four weeks later, the orocutaneous fistulae had healed.

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

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

Composite Hydrogel Embedded with Porous Microspheres for Long-Term pH-Sensitive Drug Delivery

IMPACT STATEMENT

A composite hydrogel embedded with porous microspheres fabricated by phase separation methods was developed and showed excellent long-term anticancer drug delivery capability to cancer cells.

Life threatening bleeding from an osteonecrosis of the jaw: Are bisphosphonates safe in irradiated head and neck cancer patients?

Osteonecrosis of the jaw is a significant complication secondary to radiation therapy or drug therapy, most commonly bisphosphonates. Safety data regarding the administration of bisphosphonates in bone metastatic head and neck cancer patients with history of jaw irradiation are almost non-existent. In this paper, we report the case of a Head and Neck (HNC) patient, with history of radiation therapy to the mandible region, treated with intravenous bisphosphonates for bone metastases that resulted in gross, life threatening mouth hemorrhage secondary to advanced, locally invasive ONJ.

Medium-term outcome of closed radial wedge osteotomy of the distal radius for Preiser disease with concomitant Kienböck disease: Two case reports and a literature review

RATIONALE

Idiopathic avascular necrosis of the scaphoid or lunate bone are known as Preiser disease and Kienböck disease, respectively. Although there are reports of avascular necrosis involving more than one carpal bone, concurrent idiopathic avascular necrosis of the scaphoid and lunate bones is rare, with only five cases reported in the English literature (including the two herein). Although the optimum treatment for Preiser disease with concomitant Kienböck disease has not been established, our cases underwent closed radial wedge osteotomy based on the evidence of satisfactory outcomes for treating Kienböck disease. We report the medium-term results of closed radial wedge osteotomy of the distal radius in two cases of Preiser disease with concomitant Kienböck disease.

PATIENT CONCERNS

We presented two patients with concomitant Preiser and Kienböck diseases. Although both smoked cigarettes, neither had any other risk factors; there was no history of trauma, although both women had jobs that required relatively heavy or repetitive manual labor.

DIAGNOSES

Two patients were diagnosed by radiographs and magnetic resonance imaging of the wrists.

INTERVENTIONS

A non-surgical strategy of splint immobilization and analgesia was not effective, and surgery was ultimately required.

OUTCOMES

Satisfactory medium-term results were achieved with closed radial wedge osteotomy of the distal radius in both cases. Although there was imaging evidence of progression of dorsal intercalated segmental instability deformity, neither of the patients was symptomatic and both declined salvage surgery.

LESSONS

We compare our cases and treatment strategy with others reported in the literature. Our cases suggest that closed radial wedge osteotomy of the distal radius is a safe and relatively straightforward means of treating patients with this rare combination of wrist disorders, and appears to obviate the need for more extensive salvage procedures.

Cryptococcal Maxillary Osteomyelitis and Osteonecrosis in a 18-Month-Old Dog

An 18-month-old neutered male labradoodle was treated with surgical debridement for maxillary osteomyelitis and sequestrum formation. Histopathologic findings of the necrotic bone were consistent with Cryptococcus subspecies, confirmed with latex agglutination serum titer testing. The patient responded to a combination of fluconazole and surgical debridement and was titer negative after 8 months of medical therapy. The patient never exhibited signs of systemic illness which is commonly reported with cryptococcosis. Cryptococcus subspecies infection in dogs in the Pacific Northwest is part of an ongoing outbreak in the region, first reported in 2001, and is associated with specific risk factors. This is the first published case of oral cryptococcosis from primary inoculation.

Bisphosphonate-Induced Osteonecrosis of the Jaw

Objective:

To review the risk of osteonecrosis of the jaw associated with bisphosphonates.

Data Sources:

A MEDLINE search (1966–January 2007) and a search of international Pharmaceutical Abstracts (1970–January 2007) were conducted to identify relevant literature. Additional references were reviewed from selected articles.

Study Selection and Data Extraction:

Articles related to bisphosphonate-induced osteonecrosis of the jaw were reviewed and summarized. Inclusion criteria required that articles be either case studies or case series that were reporting actual cases linking osteonecrosis of the jaw with bisphosphonate use. Articles that addressed sites of osteonecrosis not involving the jaw, teaching cases (fictitious patients), and a retrospective claims analysis paper were excluded from consideration.

Data Synthesis:

Bisphosphonates have recently been linked to osteonecrosis of the jaw, with the greatest incidence seen with the intravenous preparations zoledronic acid and pamidronate. Osteonecrosis refers to death of a part of the bone, resulting in decreased bone density. Although the majority of occurrences have been associated with the intravenous bisphosphonates, oral bisphosphonates have also been implicated. Other risk factors noted from reported cases include dental extraction or trauma to the jaw exposing part of the bone. It is difficult to determine an exact incidence of osteonecrosis of the jaw in the general population of patients prescribed bisphosphonates; however, the incidence in cancer patients is approximately 6–7%.

Conclusions:

Although discontinuation of intravenous bisphosphonates in cancer patients has been recommended, stopping oral bisphosphonates prior to dental work cannot be universally endorsed at this time, since it is unknown whether this is effective in reducing the risk of osteonecrosis of the jaw. Treatment of this condition is not well established; therefore, efforts should be directed toward prevention. Pharmacists may further counsel patients to practice good oral hygiene and regularly follow up with their dentist during therapy. Current evidence suggests limited surgical debridement with systemic and local antibiotics as treatments.

[Study on the Distribution of Constitutions of Chinese Medicine in Patients with Osteonecrosis of Femoral Head]

OBJECTIVE

To observe the distribution of constitution types of Chinese medicine (CM) in patients with osteonecrosis of femoral head (ONFH).

METHODS

Totally 130 ONFH patients were recruited. Constitution types of CM were identified in all patients. Distribution features of constitution types of CM in ONFH patients were observed. The differences of distribution in gender, age, single or bilateral hips, course of disease, staging, cause, and region were also analyzed.

RESULTS

Seventy patients were of complicated constitutions, while 60 patients were of single constitution. Among the 60 single constitution cases, yang-deficiency constitution [18 (13.9%)], damp-heat constitution [10 (7.7%)], blood-stasis constitution [7 (5.4%)], and qi-deficiency constitution [7 (5.4%)] were mainly distributed. Of the complicated constitutions, yang-deficiency dominated constitution occupied the top ratio [30 (23.1%)], followed by blood-stasis dominated constitution [15 (11.5%)], damp-heat dominated constitution [9 (6.9%)]. By putting them together, yang-deficiency constitution occupied the top constitution of CM [48 (36.9%)], followed by blood-stasis constitution [ 22 (16.9%)] and damp-heat constitution [19 (14.6%)]. The aforesaid three constitutions accounted for 68.5% of the total. There were no statistical distribution differences in gender, age, single or bilateral hips, course of disease, staging, or cause.

CONCLUSION

Yang-deficiency constitution, damp-heat constitution, and blood-stasis constitution were liable constitutions of CM in ONFH patients.

Medical treatment of osteonecrosis of the knee associated with thrombophilia-hypofibrinolysis

In 6 patients with stage II knee osteonecrosis, all 6 with thrombophilia and 4 with concurrent hypofibrinolysis, the authors prospectively determined whether anticoagulation with enoxaparin could prevent collapse and progression to osteoarthritis, ameliorate pain, and restore function. The 6 patients were treated with enoxaparin (40 to 60 mg/d for 3 or more months) as mandated by a US Food and Drug Administration-approved protocol. In post-enoxaparin prospective follow-up, patients were reassessed clinically every 4 to 6 months, and radiographs were obtained every year. The 6 patients followed up at 15.1, 7.5, 3.9, 2.25, 2, and 1 year, respectively. None progressed to joint collapse or severe osteoarthritis. Four became and remained asymptomatic at 2-, 3.9-, 7.5-, and 15.1-year follow-up, respectively. A fifth patient did not progress to collapse or severe osteoarthritis but had residual pain at 2.25-year follow-up. The sixth patient had no symptomatic benefit on enoxaparin but improved on rivaroxaban at 1-year follow-up. Two patients had recurrences of knee pain 1 and 4 years after their initial treatment with enoxaparin. One resolved after a second course of enoxaparin, and the other, with a second recurrence 1 year after the second course, resolved after a third course. Pretreatment, all 6 patients required canes, crutches, or wheelchairs, but after enoxaparin, no patient required them, and walking was unrestricted. Thrombophilia-hypofibrinolysis contributes to the pathogenesis of knee osteonecrosis. Thrombophilic-hypofibrinolytic patients with stage II knee osteonecrosis treated with enoxaparin have had no collapse or progression to severe osteoarthritis, and most have had resolution of pain and restoration of full function. This represents a major improvement compared with the natural history of untreated spontaneous knee osteonecrosis.

Successful treatment of a humeral capitulum osteonecrosis with bone morphogenetic protein-7 combined with autologous bone grafting

We present the case of a 27-year-old female with subcortical osteonecrosis of the humeral capitulum. Percutaneous retrograde drilling of the lesion and application of recombinant human bone morphogenetic protein (BMP)-7 were combined with autologous bone grafting. At follow-up the patient was almost pain-free, had normalized her range of motion, and radiography showed consolidation of the lesion without any heterotopic bone formation. By timing surgery prior to subchondral collapse, biomechanical stability of the subchondral bone was maintained. To our knowledge, this is the first report on the treatment of an osteonecrosis in this location with a BMP, and this strategy could potentially be applied in other locations with juxta-articular osteonecrosis.

Teriparatide therapy for denosumab-induced osteonecrosis of the jaw in a male osteoporotic patient

We report the first case of teriparatide adjuvant role in the management of a denosumab-induced osteonecrosis of the jaw in a male subject with idiopathic osteoporosis. Clinical benefits and CT healing were obtained within 2 months of teriparatide initiation and denosumab withdrawal. Increase in bone turnover previously described, when denosumab treatment is removed, might have a synergistic effect to the stimulating effect of teriparatide on bone remodeling to promptly heal osteonecrosis of the jaw.

[Progress and problems in oral bisphosphonate]

Oral bisphosphonates are the first class of drugs other than estrogen that have been proven to reduce fracture incidence substantially. Since they are agents that inhibit bone resorption and are hardly absorbed through intestine, researchers have been focusing on augmentation of inhibitory effects of bisphosphonates on bone resorption and prolongation of the interval of drug administration. Even though they have a break-through efficacy on preventing fractures, there remain some rare problems to be solved, such as osteonecrosis of the jaw and atypical femoral fracture, after long-term exposure to bisphosphonates.

Effect of ibandronate on spontaneous osteonecrosis of the knee: a randomized, double-blind, placebo-controlled trial

Based on this double-blind, placebo-controlled study, ibandronate has no beneficial effect on clinical and radiological outcome in patients with spontaneous osteonecrosis of the knee over and above anti-inflammatory medication.

INTRODUCTION

Observational studies suggest beneficial effects of bisphosphonates in spontaneous osteonecrosis (ON) of the knee. We investigated whether ibandronate would improve clinical and radiological outcome in newly diagnosed ON.

METHODS

In this randomized, double-blind, placebo-controlled trial, 30 patients (mean age, 57.3 ± 10.7 years) with ON of the knee were assigned to receive either ibandronate (cumulative dose, 13.5 mg) or placebo intravenously (divided into five doses 12 weeks). All subjects received additional treatment with oral diclofenac (70 mg) and supplementation with calcium carbonate (500 mg) and vitamin D (400 IU) to be taken daily for 12 weeks. Patients were followed for 48 weeks. The primary outcome was the change in pain score after 12 weeks. Secondary endpoints included changes in pain score, mobility, and radiological outcome (MRI) after 48 weeks.

RESULTS

At baseline, both treatment groups (IBN, n = 14; placebo, n = 16) were comparable in relation to pain score and radiological grading (bone marrow edema, ON). After 12 weeks, mean pain score was reduced in both ibandronate- (mean change, -2.98; 95% CI, -4.34 to -1.62) and placebo- (-3.59; 95% CI, -5.07 to -2.12) treated subjects (between-group comparison adjusted for age, sex, and osteonecrosis type, p = ns). Except for significant decrease in bone resorption marker (CTX) in ibandronate-treated subjects (p < 0.01), adjusted mean changes in all functional and radiological outcome measures were comparable between treatment groups after 24 and 48 weeks.

CONCLUSIONS

In patients with spontaneous osteonecrosis of the knee, bisphosphonate treatment (i.e., IV ibandronate) has no beneficial effect over and above anti-inflammatory medication.

Prospective biomarker evaluation in patients with osteonecrosis of the jaw who received bisphosphonates

Bone biomarkers have been suggested for the risk assessment for osteonecrosis of the jaw, a serious complication associated with bisphosphonate (BP) use; however, no consensus has been reached. This study investigated the possible associations between bone biomarkers and the development of bisphosphonates-related osteonecrosis of the jaw (BRONJ). This is a case-control study of 37 patients with BRONJ (age, 73.6±11.2years) who had at least 1 sample available at diagnosis, out of which, 35 were taking BPs for osteoporosis and 2 patients for bone metastasis. Age- and gender-matched 37 patients who had been exposed to BPs for >24months and had no evidence of BRONJ after dentoalveolar surgery served as control group. The association between biomarkers (osteocalcin [OC], deoxypyridinoline [DPD], C-terminal telopeptide of collagen I [CTX], N-terminal telopeptides [NTX], bone-specific alkaline phosphatase [BAP], and parathyroid hormone [PTH]) and BRONJ development, the effects of BP discontinuation on biomarkers, and the performance of biomarkers for risk assessment were investigated. In our study, the PTH levels were found to be significantly higher in BRONJ patients compared to controls (P<0.05). But the OC, DPD, CTX, NTX, and BAP levels were not significantly different between the 2 groups (P>0.05). The CTX level in reference to a 150pg/mL cutoff was also not significant for BRONJ development (P>0.05). Among BRONJ patients who discontinued BP, in a linear mixed model, only CTX showed a significant increase over time (β=0.002, P=0.007). The cutoff PTH level was >41.52pg/mL (AUC=0.719, P=0.009), and that of CTX was ≤0.094ng/mL (AUC=0.619, P=0.069). In conclusion, there is insufficient evidence for the risk prediction for BRONJ of current bone biomarkers; additional research is necessary.

Dental extraction as a risk factor for bisphosphonate related osteonecrosis of the jaw in cancer patients: an update

Osteonecrosis of the jaw (ONJ) is a complication related to the use of bisphosphonates (BPs). Patients receiving BPs for the treatment of malignancies are at an increased risk of developing bisphosphonate-related ONJ (BRONJ) as compared to patients receiving BPs for the treatment of other disorders such as osteoporosis. Additionally, tooth extractions have been suggested to increase the risk of BRONJ in individuals taking BPs.

OBJECTIVE

To review the role of dental extraction as a risk factor for BRONJ in cancer patients.

MATERIALS AND METHODS

Databases were searched from January 1999 up to and including July 2012 using various combinations of the following keywords: "bisphosphonate", "osteonecrosis of the jaw", "cancer", "oral" and "dental extraction".

RESULTS

Twenty two studies were included. Eighteen studies assessed the relationship between BRONJ and dental extractions in cancer patients, reporting the overall prevalence of BRONJ following extraction in this group as 3.25 +/- 2.23%. Four studies did not report a correlation between BRONJ and extractions, and recommended protocols to avoid the complication.

CONCLUSION

There is a plausible relationship between dental extractions and the development of BRONJ in cancer patients. Written informed consent must be obtained prior to dental procedures in patients at risk for developing BRONJ.

Preventive effects of the anti-vasospasm agent via the regulation of the Rho-kinase pathway on the development of steroid-induced osteonecrosis in rabbits

A number of studies have suggested that ischemia is the principal pathomechanism of osteonecrosis, however, the detailed mechanism responsible for ischemia remains unclear. We examined the effects of fasudil, an anti-vasospasm agent, on the development of steroid-induced osteonecrosis in rabbits. One group of rabbits received 15mg/kg of fasudil intravenously, which were then injected once intramuscularly with 20mg/kg of methylprednisolone (n=33), and one received methylprednisolone alone as a control (n=28). Eight rabbits from each group were sacrificed 24h after methylprednisolone injection to analyze them by the expression of endothelinA-receptor and eNOS. Two weeks after the steroid injection, the femora and humeri were examined histopathologically for the incidence of osteonecrosis. In addition, plasma from each of four osteonecrosis-positive or -negative rabbits was used for the proteomic analysis in the fasudil group. The incidence of osteonecrosis was significantly lower in the fasudil group (32%) than that in the control group (75%) (P<0.01). Immunohistochemically, endothelinA-receptor expressions levels were decreased in the smooth muscle of the bone marrow in the fasudil group in comparison to that in the control group. The eNOS expressions levels in both serum and bone marrow in the MF group were significantly higher than those in the M group (P<0.05). Based on the proteomic analysis, several proteins related to vasospasm, such as fibrinogen, thrombin, and apolipoprotein E, were identified in rabbits with osteonecrosis soon after steroid administration. This study indicates that vasospasm is one of the important factors involved in the pathogenesis of steroid-induced osteonecrosis and that the anti-vasospasm agents seem to decrease the incidence of steroid-induced osteonecrosis.

Spontaneous osteonecrosis of the knee (SONK)

PURPOSE

Spontaneous osteonecrosis of the knee (SONK/Morbus Ahlback) mainly affects the medial condyle of elderly women. It is assumed that localized vascular insufficiency leads to necrosis of the subchondral bone with subsequent disruption of the nutrition supply to the cartilage above. The aetiology remains unclear in detail. Operative treatment procedures compete against non-operative strategies, whereas the outcome is unpredictable in many cases.

METHOD

A consecutive case series of five patients suffering from SONK was analysed. All patients underwent a clinical examination, magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry scan, as well as laboratory analyses and visual analogue scale (VAS) evaluation. Our treatment regime is based on high-dose vitamin D administered orally and intravenous application of 3 mg ibandronate two times within 8 weeks. Another 8 weeks later, all patients were followed up including a follow-up MRI.

RESULTS

Within 4 weeks, all patients were free of symptoms. The MRI follow-up showed remission of the bone marrow oedema in every case studied. VAS decreased significantly from 7.4 ± 1.0 pre-interventional to 0.8 ± 1.0 post-interventional. No allergic reactions or other side effects were documented.

CONCLUSION

We showed that our treatment regime not only eliminated the pathological findings in the MRI of all cases studied, but also decreased the pain level and functional limitations within a short-time period.

LEVEL OF EVIDENCE

IV.

Parathyroid hormone applications in the craniofacial skeleton

Parathyroid hormone (PTH) is known for its ability to 'build' bone, with research in this area centered on its use as an osteoporosis therapeutic. Recent interest has developed regarding its potential for regenerative applications such as fracture healing and osseous defects of the oral cavity. Many years of investigation using murine gene-targeted models substantiate a role for signaling at the PTH/PTH-related protein (PTHrP) receptor (PPR) in intramembranous bone formation in the craniofacial region as well as in tooth development. Pre-clinical studies clearly support a positive role of intermittent PTH administration in craniofacial bones and in fracture healing and implant integration. A few human clinical studies have shown favorable responses with teriparatide (the biologically active fragment of PTH) administration. Favorable outcomes have emerged with teriparatide administration in patients with osteonecrosis of the jaw (ONJ). New delivery strategies are in development to optimize targeted application of PTH and to help maximize local approaches. The promising host-modulating potential of PTH requires more information to further its effectiveness for craniofacial regeneration and osseous wound-healing, including a better delineation of cellular targets, temporal effects of PTH action, and improved approaches for local/targeted delivery of PTH.

Glucocorticoid-induced osteoporosis and osteonecrosis

Glucocorticoid administration is the most common cause of secondary osteoporosis and the leading cause of nontraumatic osteonecrosis. In patients receiving long-term therapy, glucocorticoids induce fractures in 30% to 50% and osteonecrosis in 9% to 40%. This article reviews glucocorticoid-induced osteoporosis and osteonecrosis, addressing the risk factors, pathogenesis, evaluation, treatment, and uncertainties in the clinical management of these disorders.

Glucocorticoid-induced osteonecrosis

Awareness of the need for prevention of glucocorticoid-induced fractures is growing, but glucocorticoid administration is often overlooked as the most common cause of nontraumatic osteonecrosis. Glucocorticoid-induced osteonecrosis develops in 9-40% of patients receiving long-term therapy although it may also occur with short-term exposure to high doses, after intra-articular injection, and without glucocorticoid-induced osteoporosis. The name, osteonecrosis, is misleading because the primary histopathological lesion is osteocyte apoptosis. Apoptotic osteocytes persist because they are anatomically unavailable for phagocytosis and, with glucocorticoid excess, decreased bone remodeling retards their replacement. Glucocorticoid-induced osteocyte apoptosis, a cumulative and unrepairable defect, uniquely disrupts the mechanosensory function of the osteocyte-lacunar-canalicular system and thus starts the inexorable sequence of events leading to collapse of the femoral head. Current evidence indicates that bisphosphonates may rapidly reduce pain, increase ambulation, and delay joint collapse in patients with osteonecrosis.

Early appearance of osteonecrosis of the jaw after zoledronic acid in a patient with a long history of taking oral bisphosphonates

Osteonecrosis of the jaw (ONJ) is a serious side effect in patients receiving intravenous nitrogen-containing bisphosphonates (B). It has also been reported to occur due to oral administration of B. Most cases will appear after receiving B for more than 1 year. The authors report a case of a 67-year-old woman with osteoporosis who had received oral alendronate sodium for 2 years and stopped the treatment due to dyspepsia. 18 months later she was diagnosed with breast cancer and bone metastases. She started a treatment based on aromatase inhibitors and zoledronic acid (Z). She developed ONJ soon after the third administration. She was treated with antibiotics, anti-inflammatories and a chlorexidine colutory. She recovered 3 months later. ONJ secondary to Z may occur also earlier than it was thought in patients with a history of taking oral B.

Bisphosphonates in orthopedic applications

Bisphosphonates (BPs) exert potent effects on the skeleton. As such, there are important questions relating to how treatment with BPs for metabolic disorders might affect outcomes of orthopedic problems. A further question is what role, if any, might BPs play as adjunctive therapeutics for orthopedic problems. This article outlines the research thus far in the application of BPs to the management of osteonecrosis, bone repair, and joint arthroplasty. Many animal studies show a benefit to decreasing bone resorption in models of osteonecrosis. These include studies in both small and large animals, backed up by limited human data. Further clinical trials are underway for this indication. In bone repair, again, multiple studies exist. There are concerns that BPs could interfere with the normal processes of healing. Some of the controversy about benefits or adverse effects of BPs in this context can be distilled down to effects of dosing and administration. With some exceptions, longer intervals between dosing seem to be more beneficial while not producing adverse healing effects in animal studies. In joint arthroplasty, animal studies suggest a role for topical or systemic BPs for enhancing bone on-growth to implant surfaces and strength of mechanical fixation, although these are yet to be confirmed in clinical studies. Clinical studies show that BPs inhibit periprosthetic bone loss due to strain-adaptive remodeling and after impaction bone grafting, although an efficacy in inhibiting inflammatory bone loss due to wear particle-induced osteolysis has not been confirmed. Lastly, as anabolic drugs have become available, there is increasing interest in their combined use with BPs. From experimental data, manipulation of both the anabolic and catabolic responses is a powerful approach in models of bone repair.