The effect of 8 or 5 years of denosumab treatment in postmenopausal women with osteoporosis: results from the FREEDOM Extension study

RANKL blockade for erosive hand osteoarthritis: a randomized placebo-controlled phase 2a trial

Erosive hand osteoarthritis (OA) is a prevalent and disabling disease with limited treatment options. Here we present the results of a monocentric, placebo-controlled, double-blind, randomized phase 2a clinical trial with denosumab, a receptor activator of nuclear factor-κB ligand inhibitor, evaluating the effects on structure modification in erosive hand OA. Patients were randomized to 48 weeks treatment with denosumab 60 mg every 3 months (n = 51, 41 females) or placebo (n = 49, 37 females). The primary (radiographic) endpoint was the change in the total Ghent University Scoring System (GUSS) at week 24, where positive changes correspond to remodeling and negative changes to erosive progression. Secondary endpoints were the change in the GUSS at week 48 and the number of new erosive joints at week 48 by the anatomical phase scoring system. Baseline mean GUSS (standard deviation) of target joints was 155.9 (69.3) in the denosumab group and 158.7 (46.8) in the placebo group. The primary endpoint was met with an estimated difference between groups of 8.9 (95% confidence interval (CI) 1.0 to 16.9; P = 0.024) at week 24. This effect was confirmed at week 48 (baseline adjusted GUSS (standard error of the mean) denosumab and placebo were 163.5 (2.9) and 149.2 (3.9), respectively; with an estimated difference between groups of 14.3 (95% CI 4.6 to 24.0; P = 0.003)). At patient level, more new erosive joints were developed in the placebo group compared with denosumab at week 48 (odds ratio 0.24 (95% CI 0.08 to 0.72); P = 0.009). More adverse events occurred in the placebo group (125 events in 44 patients (90%)) compared with the denosumab group (97 events in 41 patients (80%)). These results demonstrate that denosumab has structure modifying effects in erosive hand OA by inducing remodeling and preventing new erosive joints. EU Clinical Trials Register identifier 2015-003223-53 .

Ozone therapy effect in medication-related osteonecrosis of the jaw as prevention or treatment: microtomographic, confocal laser microscopy and histomorphometric analysis

OBJECTIVE

This study aimed to evaluate the efficacy of ozone therapy in the preoperative (prevention) and/or postoperative (treatment) of MRONJ.

MATERIAL AND METHODS

Forty male Wistar rats were caudally treated with zoledronic acid (ZOL) and to ozone therapy before extraction (prevention, POG), after extraction (treatment, TOG), or both (prevention and treatment, TPOG), and treated with saline (SAL). The animals received intramuscular fluorochrome (calcein and alizarin), and 28 days postoperatively, they were euthanized, and the tissues were subjected to microtomographic computed tomography (microCT), LASER confocal, and histomorphometric analyses.

RESULTS

Micro-CT showed a higher bone volume fraction average in all groups than that in the ZOL group (P < 0.001), the ZOL group showed high porosity (P = 0.03), and trabecular separation was greater in the TOG group than in the POG group (P < 0.05). The mineral apposition rate of the POG group was high (20.46 ± 6.31) (P < 0.001), followed by the TOG group (20.32 ± 7.4). The TOG group presented the highest mean newly formed bone area (68.322 ± 25.296) compared with the ZOL group (P < 0.05), followed by the SAL group (66.039 ± 28.379) and ZOL groups (60.856 ± 28.425).

CONCLUSIONS

Ozone therapy modulated alveolar bone repair in animals treated with ZOL, mainly after surgery trauma, leading to bone formation as healing tissue.

CLINICAL RELEVANCE

Osteonecrosis has been a challenge in dentistry, and owing to the lack of a consensus regarding therapy, studies presenting new therapies are important, and ozone has been one of the therapies explored empirically.

Low-Intensity Pulsed Ultrasound Maintains Bone Mass After Withdrawal of Human Parathyroid Hormone in Ovariectomized Mice

The intermittent injection of teriparatide, a recombinant fragment of human parathyroid hormone (PTH 1-34), activates anabolic activity on bone turnover. However, the PTH administration period is limited to 2 years. Thus, sequential therapy after discontinuation of PTH is required. Low-intensity pulsed ultrasound (LIPUS) has been widely used for bone fracture healing. In this study, we examined the effects of LIPUS on bone mass after PTH withdrawal in ovariectomized (OVX) model mice. The LIPUS-non-irradiated femoral trabecular bone mineral density (BMD) in the treated after PTH withdrawal was significantly decreased. Meanwhile, the femoral BMD in the OVX + PTH-LIPUS group was remarkably higher than that of the OVX group. Additionally, mRNA expression of Runx2, Osterix, Col1a1, and ALP increased significantly following LIPUS irradiation after PTH withdrawal. These results suggest that LIPUS protected against femoral trabecular BMD loss and up-regulated the osteogenic factors following PTH withdrawal in OVX mice.

Adherence of denosumab treatment for low bone mineral density in Japanese people living with HIV: a retrospective observational study

BACKGROUND

Long-term care issues, specifically metabolic bone disorders, are a concern for people living with human immunodeficiency virus (PLWH) who undergo life-long antiretroviral therapy (ART). Previous clinical trials with denosumab, an anti-RANKL antibody inhibitor, have revealed its effectiveness in increasing bone mineral density (BMD) in patients with osteoporosis. However, there are limited data on adherence and effectiveness of denosumab treatment for osteoporosis in PLWH. Hence, this study aimed to investigate the adherence and effectiveness of denosumab treatment for osteoporosis in Japanese PLWH.

METHODS

This study is a retrospective exploratory analysis of 29 Japanese PLWH who initiated denosumab treatment for osteoporosis, between 2013 and 2021. The study included patients who received at least one dose of denosumab every 6 months. Adherence and persistence were defined as receiving two consecutive injections of denosumab 6 months ± 4 weeks apart and 6 months + 8 weeks apart, respectively. The primary outcome measure of the study was the adherence of denosumab treatment for 24 months. The secondary outcome measures included treatment persistence and BMD. The period after January 2020 was defined as the coronavirus disease 2019 (COVID-19) pandemic period, and its impact on adherence was investigated.

RESULTS

The treatment adherence rates at 12 and 24 months were 89.7% and 60.7%, respectively. By contrast, the treatment persistence at 12 and 24 months was 100% and 85.7%, respectively. More patients in the group who initiated denosumab treatment after the COVID-19 pandemic reached non-adherence than in the group who initiated denosumab treatment before the pandemic. BMD at the lumbar spine and femoral neck significantly increased compared to that at baseline, with median percentage changes of 8.7% (p < 0.001) and 3.5% (p = 0.001), respectively.

CONCLUSIONS

The results showed that patients in the study had a high rate of non-adherence but a lower rate of non-persistence. Additionally, PLWH on ongoing ART experienced increased BMD with denosumab treatment. This study provides an opportunity to improve future strategies for denosumab treatment in the Japanese PLWH.

The Sequential Therapy in Osteoporosis

Background

Osteoporosis management often involves a sequential treatment approach to optimize patient outcomes and minimize fracture risks. This strategy is tailored to individual patient characteristics, treatment responses, and fracture risk profiles.

Methods

A thorough literature review was systematically executed using prominent databases, including PubMed and EMBASE. The primary aim was to identify original articles and clinical trials evaluating the effectiveness of sequential therapy with anti-osteoporosis drugs, focusing on the period from 1995 to 2023. The analysis encompassed an in-depth examination of osteoporosis drugs, delineating their mechanisms of action, side effects, and current trends as elucidated in the literature.

Results and Discussion

Our study yielded noteworthy insights into the optimal sequencing of pharmacologic agents for the long-term treatment of patients necessitating multiple drugs. Notably, the achievement of optimal improvements in bone mass is observed when commencing treatment with an anabolic medication, followed by the subsequent utilization of an antiresorptive drug. This stands in contrast to initiating therapy with a bisphosphonate, which may potentially diminish outcomes in the post-anabolic intervention period. Furthermore, it has been discerned that caution should be exercised against transitioning from denosumab to PTH homologs due to the adverse effects of heightened bone turnover and sustained weakening of bone structure. Despite the absence of fracture data substantiating the implementation of integrated anabolic/antiresorptive pharmacotherapy, the incorporation of denosumab and teriparatide presents a potential avenue worthy of consideration for individuals at a heightened vulnerability to fragility fractures.

Conclusions

A judiciously implemented sequential treatment strategy in osteoporosis offers a flexible and tailored approach to address diverse clinical scenarios, optimizing fracture prevention and patient outcomes.

Biologic Antiresorptive: Denosumab

Background

Osteoporosis is an age-related common bone disorder characterized by low bone mineral density and increased fragility fracture risk. Various Antiresorptive medications are being used to target osteoclast mediated bone resorption to prevent bone loss and reduce fracture risk.

About Denosumab

Denosumab is a novel biological antiresorptive drug that belongs to the class of monoclonal antibodies. It binds to and inhibits the cytokine receptor activator of nuclear factor kappa-B ligand (RANKL), which is requisite for osteoclast differentiation, function and survival.

Effectiveness

Denosumab has been shown to be a potent and effective therapy for osteoporosis, with clinical trial data demonstrating significant improvement in bone mineral density (BMD) and reductions in fracture risk at various skeletal sites for more than 10 years of treatment.

Safety Profile

Denosumab has a favourable benefit/risk profile, with low rates of complications such as infection, atypical femoral fracture and osteonecrosis of the jawbone.

Challenges

However, denosumab treatment requires continuous administration, as discontinuation leads to rapid bone mineral loss and increased risk of multiple vertebral fractures due to rebound of bone turnover. Therefore, modification to another anti-osteoporosis drug therapy after denosumab discontinuation is required to maintain bone health.

Conclusion

Denosumab is a promising biological antiresorptive therapy for osteoporosis that offers high efficacy and safety, but also poses challenges for long-term management.

Risk comparison of osteonecrosis of the jaw in osteoporotic patients treated with bisphosphonates vs. denosumab: a multi-institutional retrospective cohort study in Taiwan

In this multi-institutional retrospective cohort study, we compared the long-term risk of osteonecrosis of the jaw following the use of denosumab vs. bisphosphonates in osteoporotic patients. After 2-year use, the likelihood of osteonecrosis of the jaw is lower with denosumab compared to bisphosphonates, and the difference increases with time.

PURPOSE

To compare the long-term risk of osteonecrosis of the jaw (ONJ) between osteoporotic patients treated with bisphosphonates (BPs) and denosumab.

METHODS

This multi-institutional retrospective cohort study included patients aged > 40 years with osteoporosis between January 2010 and December 2018. Patients who met the eligibility criteria were divided into BPs and denosumab groups by propensity score matching (PSM). The risk of ONJ of denosumab vs. BPs was estimated using a Cox proportional hazards model and was described by the cumulative incidence rate using the Kaplan-Meier method.

RESULTS

A total of 84,102 patients with osteoporosis were enrolled, among whom, 8962 were eligible for inclusion based on their first-line drug use (denosumab, n = 3,823; BPs, n = 5,139). Following PCM matching (1:1), the BPs and denosumab groups included 3665 patients each. The incidence density of ONJ in the denosumab and BPs matching groups was 1.47 vs. 2.49 events (per 1000 person-years), respectively. The hazard ratio of ONJ in the denosumab vs. BPs group was estimated as 0.581 (95% confidence interval: 0.33-1.04, p = 0.07). The cumulative incidence rates of ONJ in both groups were similar for the first and second years of drug use (p = 0.062), but significantly different from the third year onwards (p = 0.022). The severity of ONJ was not significantly different between the two groups.

CONCLUSION

In osteoporotic patients, after 2 years of use, the likelihood of ONJ being induced by denosumab is lower than that of BPs, and the difference increases with time.

Denosumab Use in Chronic Kidney Disease Associated Osteoporosis: A Narrative Review

Chronic kidney disease (CKD) and hemodialysis (HD) patients have a high incidence of bone disease and increased fracture risk, making effective management of their bone health a clinical challenge. Denosumab, a human monoclonal antibody, has been investigated as a therapeutic option in this patient population. In this review, we summarize the current evidence on the efficacy and safety of denosumab in CKD and HD patients. A comprehensive search of the relevant literature was conducted, including randomized controlled trials, observational studies, and meta-analyses. The findings suggest that denosumab reduces the risk of fractures and improves bone mineral density in all stages of CKD. The results of this review support the use of denosumab as a promising option for managing bone disease in CKD and HD patients.

Long-Term Effect of Denosumab on Bone Disease in Patients with CKD

BACKGROUND

The effect of long-term denosumab therapy and of denosumab discontinuation on the cortical bone of the hip regions in dialysis patients has not been studied.

METHODS

This retrospective study investigated the cortical and trabecular compartments and estimated strength indices of the hip region, obtained using 3D-SHAPER software, after a maximum of 5 years of denosumab therapy in 124 dialysis patients. A Wilcoxon signed-rank test was used to identify the differences in each parameter before and after denosumab initiation. Similarly, we investigated the changes in these parameters after denosumab discontinuation in 11 dialysis patients.

RESULTS

Integral and trabecular volumetric bone mineral densities (BMD) were significantly lower at the start of denosumab therapy than those in 1 year before denosumab initiation. After starting denosumab, areal BMD (median change +7.7% [interquartile range (IQR), +4.6 to +10.6]), cortical volumetric BMD (median change +3.4% [IQR, +1.0 to +4.7]), cortical surface BMD (median change +7.1% [IQR, +3.4 to +9.4]), and cortical thickness (median change +3.2% [IQR, +1.8 to +4.9]) showed a significantly higher trend for 3.5 years, which then stabilized at a higher value compared with baseline. A similar trend in the trabecular volumetric BMD (median change +9.8% [IQR, +3.8 to +15.7]) was observed over 2.5 years, with a higher value maintained thereafter. The whole area of the hip region improved after denosumab therapy. Similar trajectories were also found in the estimated strength indices. Conversely, at 1 year after denosumab discontinuation, these 3D parameters and estimated strength indices tended to largely worsen. The lateral aspect of the greater trochanter was the most pronounced location showing volumetric BMD loss.

CONCLUSIONS

The BMD of both cortical and trabecular components in the hip region was significantly higher after starting denosumab therapy. However, these measurements exhibited a trend of declining substantially after the discontinuation of denosumab.

Using sequential pharmacotherapy for the treatment of osteoporosis: an update of the literature

INTRODUCTION

Osteoporosis, which is characterized by compromised bone density and heightened susceptibility to fractures, is a substantial public health concern, especially among the aging population. Underdiagnosis, undertreatment, and therapy non-adherence contribute to its impact. Anabolic and dual-action agents like teriparatide, abaloparatide, and romosozumab have emerged as effective treatments, allowing rapid gains in bone mineral density (BMD) and reducing fracture risk. However, administering treatments in the correct order is paramount, with an 'anabolic first' approach gaining traction for patients at high risk of fractures. This strategy involves starting anabolic therapies, followed by antiresorptive agents as maintenance therapy. It is important to note that the effectiveness of anabolic agents differs between treatment-naive and previously treated patients: tailored treatment approaches are therefore necessary. This comprehensive strategy adheres to clinical guidelines, emphasizing individualized care, early intervention, and patient-centered management to mitigate the burden of osteoporosis and enhance patients' quality of life.

AREA COVERED

The aim of this review is to summarize recent evidence on the sequential treatment of osteoporosis and to provide recommendations on the best treatment strategies.

EXPERT OPINION

Effective treatments, such as anabolic agents, are key in high-risk patients, who require an 'anabolic first' approach. Sequential therapy, specifically tailored to a patient's history, can help to optimize prevention and management of fractures.

JAK/STAT as a Potential Therapeutic Target for Osteolytic Diseases

Several cytokines with major biological functions in inflammatory diseases exert their functions through the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signal transduction pathway. JAKs phosphorylate the cytoplasmic domain of the receptor, inducing the activation of its substrates, mainly the proteins known as STATs. STATs bind to these phosphorylated tyrosine residues and translocate from the cytoplasm to the nucleus, further regulating the transcription of several genes that regulate the inflammatory response. The JAK/STAT signaling pathway plays a critical role in the pathogenesis of inflammatory diseases. There is also increasing evidence indicating that the persistent activation of the JAK/STAT signaling pathway is related to several inflammatory bone (osteolytic) diseases. However, the specific mechanism remains to be clarified. JAK/STAT signaling pathway inhibitors have gained major scientific interest to explore their potential in the prevention of the destruction of mineralized tissues in osteolytic diseases. Here, our review highlights the importance of the JAK/STAT signaling pathway in inflammation-induced bone resorption and presents the results of clinical studies and experimental models of JAK inhibitors in osteolytic diseases.

Denosumab for osteoporosis in patients with primary hyperparathyroidism and mild-to-moderate renal insufficiency

PURPOSE

We aimed to assess the efficacy and safety of denosumab in postmenopausal women with primary hyperparathyroidism (PHPT)-related osteoporosis and chronic kidney disease (CKD).

METHODS

Women over 50 years of age with PHPT or postmenopausal osteoporosis (PMO) were retrospectively recruited into this longitudinal study. These PHPT and PMO groups were further categorized into subgroups based on the presence of CKD (Glomerular filtration rate (GFR) < 60 mL/min/1.73 m²). All patients were given denosumab over 24 months due to verified osteoporosis. The primary outcomes were changes in bone mineral density (BMD) and serum calcium levels.

RESULTS

145 postmenopausal women median age 69 [63;77] were recruited and assigned to one of the subgroups: PHPT patients with CKD (n = 22), PHPT patients without CKD (n = 38), PMO patients with CKD (n = 17) and PMO patients without CKD (n = 68). Denosumab treatment significantly increased BMD in patients with PHPT-related osteoporosis and CKD: median T-score L1-L4 from -2.0 to -1.35 (p < 0.001), femur neck from -2.4 to -2.1 (p = 0.012), radius 33% from -3.2 to -3 (p < 0.05)) at 24 months. Changes in BMD were similar in all four studied groups compared to baseline. A marked decline in calcium was noted in the primary study group of PHPT with CKD (median ΔCa = -0.24 mmol/L p < 0.001), compared to PHPT without CKD (median ΔCa = -0.08 mmol/L p < 0.001) and PMO with or without CKD. Denosumab treatment was well-tolerated with no serious adverse events.

CONCLUSION

Denosumab treatment was similarly effective at increasing BMD in patients with PHPT and PMO with and without renal insufficiency. The calcium lowering effects of denosumab were most significant in patients with PHPT and CKD. The safety of denosumab did not differ among participants with and without CKD.

MRONJ of the Mandible—From Decortication to a Complex Jaw Reconstruction Using a CAD/CAM-Guided Bilateral Scapula Flap

Medication-related osteonecrosis of the jaw (MRONJ) has been an integral part of the maxillofacial patient population for some time. The therapeutic concept ranges from conservative approaches over less extended decortications to major jaw resections, which can result in a considerable loss of quality of life. Based on three case reports, this paper presents the long-term history of patients with MRONJ of the mandible, whose disease ultimately resulted in partial or total mandibular resection and subsequent multisegmental reconstruction using a microvascular anastomosed bone flap. Furthermore, a suitable alternative for complex mandibular reconstruction is demonstrated when using a free fibula flap is not possible. The options are limited, particularly when multisegmental restoration of mandibular continuity is required. One case presents a mandible reconstruction using a CAD/CAM-guided bilateral scapular free flap (CAD/CAM = Computer-Aided Design and Manufacturing), which has not been described for this purpose before. Due to the complexity, computer-assisted surgery and patient-specific implants seem reasonable, which is why a special focus was applied to this topic.

Effectiveness and Safety of Treatments to Prevent Fractures in People With Low Bone Mass or Primary Osteoporosis: A Living Systematic Review and Network Meta-analysis for the American College of Physicians

BACKGROUND

The prevalence of osteoporosis is increasing in the United States.

PURPOSE

To evaluate low bone mass and osteoporosis treatments to prevent fractures.

DATA SOURCES

Ovid MEDLINE ALL, Ovid Evidence Based Medicine Reviews: Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and ClinicalTrials.gov from 2014 through February 2022.

STUDY SELECTION

Adults receiving eligible interventions for low bone mass or osteoporosis. Randomized controlled trials (RCTs) for fracture outcomes, and RCTs and large observational studies (n ≥1000) for harms.

DATA EXTRACTION

Abstracted by 1 reviewer and verified by a second. Independent, dual assessments of risk of bias and certainty of evidence (CoE).

DATA SYNTHESIS

We included 34 RCTs (in 100 publications) and 36 observational studies. Bisphosphonates and denosumab reduced hip, clinical and radiographic vertebral, and other clinical fractures in postmenopausal females with osteoporosis (moderate to high CoE). Bisphosphonates for 36 months or more may increase the risk for atypical femoral fractures (AFFs) and osteonecrosis of the jaw (ONJ), but the absolute risks were low. Abaloparatide and teriparatide reduced clinical and radiographic vertebral fractures but increased the risk for withdrawals due to adverse events (WAEs; moderate to high CoE). Raloxifene and bazedoxifene for 36 months or more reduced radiographic vertebral but not clinical fractures (low to moderate CoE). Abaloparatide, teriparatide, and sequential romosozumab, then alendronate, may be more effective than bisphosphonates in reducing clinical fractures for 17 to 24 months in older postmenopausal females at very high fracture risk (low to moderate CoE). Bisphosphonates may reduce clinical fractures in older females with low bone mass (low CoE) and radiographic vertebral fractures in males with osteoporosis (low to moderate CoE).

LIMITATION

Few studies examined participants with low bone mass, males, or Black-identifying persons, sequential therapy, or treatment beyond 3 years.

CONCLUSION

Bisphosphonates, denosumab, abaloparatide, teriparatide, and romosozumab, followed by alendronate, reduce clinical fractures in postmenopausal females with osteoporosis. Abaloparatide and teriparatide increased WAEs; longer duration bisphosphonate use may increase AFF and ONJ risk though these events were rare.

PRIMARY FUNDING SOURCE

American College of Physicians. (PROSPERO: CRD42021236220).

Lessons learned from long-term side effects after zoledronic acid infusion following denosumab treatment: a case report and review of the literature

BACKGROUND

Zoledronic acid is an intravenous, highly potent aminobisphosphonate for use in patients with primary or secondary osteoporosis. Zoledronic acid-induced prolonged side-effects are well known and quite common. However, severe side-effects can be a threat to life. We report a case of severe side-effects induced by zoledronic acid infusion, and its positive effect on long-term back pain.

CASE PRESENTATION

In 2012, a 62-year-old white native Finnish woman was operated on for an estrogen and progesterone receptor-positive breast cancer. After radiotherapy, an aromatase inhibitor (letrozole) was started. Nine months after the operation, the patient suffered a low-energy compression fracture of Th XII. She received denosumab to prevent fragility fractures and to improve bone mineral density. Letrozole was discontinued after 5.5 years, and the last denosumab injection was given after 7 years. Six months later, at the age of 71 years, the patient received a single intravenous zoledronic acid infusion. Suddenly, at 10 hours from the infusion, she complained of severe trismus, muscle twitching, spasms, and tingling, matching hypocalcemia and several other symptoms. Her serum 25-hydroxyvitamin D concentration was high (163 nmol/L), the concentration of serum calcium and calcium-ion was normal (2.32 mmol/L and 1.23 mmol/L, respectively). However, the neutrophil to lymphocyte ratio (NLR) was low (1.6). A complete recovery took 2 months. Zoledronic acid infusion also had a positive effect: for many years, the patient had suffered low back pain and strain, which came to an end after this single infusion.

CONCLUSION

It is important that the potential patients receive sufficient information about the possibility of side-effects following the administration of intravenous zoledronic acid. To ensure that a zoledronic acid infusion is given as safely as possible, the safety information should include that the patient should not be left without monitoring for a minimum 24 hours after the infusion. Being alone and experiencing serious side-effects may lead to acute cardiac problems. Furthermore, the chronic low back pain and strain that our patient suffered for many years has clearly reduced for 16 months after infusion, so far. We conclude that this is a positive effect of zoledronic acid.

The why and how of sequential and combination therapy in osteoporosis. A review of the current evidence

It is now well recognized that over the lifetime of a patient with osteoporosis, more than one medication will be needed to treat the disease and to decrease fracture risk. Though current gaps in osteoporosis therapy can be potentially mitigated with sequential and combination regimens, how to move seamlessly amongst the multiple treatments currently available for osteoporosis for sustained efficacy is still unclear. Data from recent studies show that an anabolic agent such as teriparatide or romosozumab followed by an antiresorptive affords maximal gain in BMD and possibly better and earlier fracture risk reduction compared to a regimen which follows the opposite sequence. Sequentially moving to a bisphosphonate such as alendronate from an anabolic agent such as abaloparatide has also been shown to preserve the fracture reduction benefits seen with the latter. This sequence of an anabolic agent followed by an antiresorptive should especially be considered in the high-risk patient with imminent fracture risk to rapidly reduce the risk of subsequent fractures. The data surrounding optimum timing of initiation of bisphosphonate therapy following denosumab discontinuation is still unclear. Though data suggests that combining a bisphosphonate with teriparatide does not provide substantial BMD gains compared to monotherapy, the concomitant administration of denosumab with teriparatide has been shown to significantly increase areal BMD as well as to increase volumetric BMD and estimated bone strength. This narrative review explores the available evidence regarding the various sequential and combination therapy approaches and the potential role they could play in better managing osteoporosis.

Discovery of small molecule agonists of the Relaxin Family Peptide Receptor 2

The relaxin/insulin-like family peptide receptor 2 (RXFP2) belongs to the family of class A G-protein coupled receptors (GPCRs) and it is the only known target for the insulin-like factor 3 peptide (INSL3). The importance of this ligand-receptor pair in the development of the gubernacular ligament during the transabdominal phase of testicular descent is well established. More recently, RXFP2 has been implicated in maintaining healthy bone formation. In this report, we describe the discovery of a small molecule series of RXFP2 agonists. These compounds are highly potent, efficacious, and selective RXFP2 allosteric agonists that induce gubernacular invagination in mouse embryos, increase mineralization activity in human osteoblasts in vitro, and improve bone trabecular parameters in adult mice. The described RXFP2 agonists are orally bioavailable and display favorable pharmacokinetic properties, which allow for future evaluation of the therapeutic benefits of modulating RXFP2 activation in disease models.

Specific small molecule RXFP2 agonists with favorable pharmacokinetic properties induce gubernacular invagination in mouse embryos, increase mineralization activity in human osteoblasts in vitro, and improve bone trabecular parameters in adult mice.

Atypical femoral fracture in a bisphosphonate-naïve patient on denosumab for osteoporosis

A post-menopausal Caucasian woman sustained an atypical femoral fracture (AFF) after 5-years continuous denosumab for osteoporosis without prior bisphosphonate exposure. This is only the fifth case reported of AFF in a bisphosphonate-naïve patient receiving denosumab for osteoporosis. Although rare, physicians should consider AFF in patients taking denosumab even without prior bisphosphonate exposure.

INTRODUCTION

Denosumab has demonstrated overwhelmingly favourable skeletal benefit/risk profile in managing post-menopausal osteoporosis with up to 10-year exposure in the extension of the pivotal FREEDOM randomised placebo-controlled trial. Four previous cases of atypical femoral fracture have been reported in bisphosphonate-naïve patients receiving denosumab for osteoporosis.

METHODS

We present an 85-year-old Caucasian post-menopausal woman without prior fragility fracture who sustained unilateral atypical femoral fracture after 5-years continuous subcutaneous denosumab for osteoporosis. She had no prior bisphosphonate or glucocorticoid exposure and had known chronic kidney disease.

RESULTS

X-ray scan demonstrated complete, non-comminuted left proximal femoral shaft fracture meeting radiographic criteria for an atypical femoral fracture. Computed tomography (CT) scan lower limbs revealed unusual side-by-side appearance of proximal and distal fragments of left proximal femur. DXA BMD was artefactually elevated at lumbar spine (1.504 g/cm², T-score + 2.5) and low-normal at right femoral neck (0.856 g/cm², T-score -1.0). Serum biochemistry showed renal impairment at baseline (eGFR 30 mL/min/1.73m²). Low-normal serum C telopeptide of type 1 collagen (CTX) (230 ng/L) indicated therapeutic suppression of bone resorption.

CONCLUSION

The patient underwent intramedullary nailing of the femur and denosumab was ceased. This is only the fifth case reported of atypical femoral fracture in a bisphosphonate-naïve patient receiving denosumab for osteoporosis. Although rare, physicians should maintain a high index of suspicion for atypical femoral fracture in a patient taking denosumab even without prior bisphosphonate exposure.

The clinician's guide to prevention and treatment of osteoporosis

Osteoporosis is the most common metabolic bone disease in the USA and the world. It is a subclinical condition until complicated by fracture(s). These fractures place an enormous medical and personal burden on individuals who suffer from them and take a significant economic toll. Any new fracture in an adult aged 50 years or older signifies imminent elevated risk for subsequent fractures, particularly in the year following the initial fracture. What a patient perceives as an unfortunate accident may be seen as a sentinel event indicative of bone fragility and increased future fracture risk even when the result of considerable trauma. Clinical or subclinical vertebral fractures, the most common type of osteoporotic fractures, are associated with a 5-fold increased risk for additional vertebral fractures and a 2- to 3-fold increased risk for fractures at other sites. Untreated osteoporosis can lead to a vicious cycle of recurrent fracture(s), often resulting in disability and premature death. In appropriate patients, treatment with effective antifracture medication prevents fractures and improves outcomes. Primary care providers and medical specialists are critical gatekeepers who can identify fractures and initiate proven osteoporosis interventions. Osteoporosis detection, diagnosis, and treatment should be routine practice in all adult healthcare settings. The Bone Health and Osteoporosis Foundation (BHOF) - formerly the National Osteoporosis Foundation - first published the Clinician's Guide in 1999 to provide accurate information on osteoporosis prevention and treatment. Since that time, significant improvements have been made in diagnostic technologies and treatments for osteoporosis. Despite these advances, a disturbing gap persists in patient care. At-risk patients are often not screened to establish fracture probability and not educated about fracture prevention. Most concerning, the majority of highest risk women and men who have a fracture(s) are not diagnosed and do not receive effective, FDA-approved therapies. Even those prescribed appropriate therapy are unlikely to take the medication as prescribed. The Clinician's Guide offers concise recommendations regarding prevention, risk assessment, diagnosis, and treatment of osteoporosis in postmenopausal women and men aged 50 years and older. It includes indications for bone densitometry as well as fracture risk thresholds for pharmacologic intervention. Current medications build bone and/or decrease bone breakdown and dramatically reduce incident fractures. All antifracture therapeutics treat but do not cure the disease. Skeletal deterioration resumes sooner or later when a medication is discontinued-sooner for nonbisphosphonates and later for bisphosphonates. Even if normal BMD is achieved, osteoporosis and elevated risk for fracture are still present. The diagnosis of osteoporosis persists even if subsequent DXA T-scores are above - 2.5. Ongoing monitoring and strategic interventions will be necessary if fractures are to be avoided. In addition to pharmacotherapy, adequate intake of calcium and vitamin D, avoidance of smoking and excessive alcohol intake, weight-bearing and resistance-training exercise, and fall prevention are included in the fracture prevention armamentarium. Where possible, recommendations in this guide are based on evidence from RCTs; however, relevant published data and guidance from expert clinical experience provides the basis for recommendations in those areas where RCT evidence is currently deficient or not applicable to the many osteoporosis patients not considered for RCT participation due to age and morbidity.

Effect of denosumab treatment on bone mineral density and bone turnover markers in osteoporotic patients: real-life experience 2-year follow-up

Denosumab leads to improvements in BMD levels and is a well-tolerated agent according to results of randomized controlled studies but results in real-life setting are important to evaluate drug adherence and real-life efficiency. In this study, we present the results of 305 patients that were treated with denosumab in our clinic.

INTRODUCTION

The long-term efficacy of anti-osteoclastic drugs in treatment of osteoporosis is well known. Denosumab, a novel human monoclonal antibody, is an anti-osteoclastic agent that has been shown to lead to reductions in vertebral, nonvertebral, and hip fracture risk in randomized and observational studies. Real-life data of this agent is increasing. In this study, we presented our real-life data about the 2-year follow-up of patients under denosumab treatment.

METHODS

Osteoporotic patients who were treated with at least one denosumab injection between 2014 and 2020 years were included. Clinical and demographic data, bone turnover markers, and radiological reports (bone mineral densitometry (BMD), vertebral x-ray) were obtained from patient files retrospectively.

RESULTS

A total of 305 patients (f/m: 275/30, 68.1 ± 11.05 years) were included. The median injection number was 4 (1-10). Two hundred seventy-three patients (89.8%) were persistent on treatment at the 12th month; 175 patients (57.3%) were persistent at 24th month. Sixty-eight patients (22%) were not using denosumab anymore, 55 of the patients were not continuing by doctor desicion and 13 were not continuing due to patient-related causes. Median BMD levels significantly increased from 0.809 (0.2-1.601, IQR: 0.136) to 0.861 (0.517-1.607, IQR: 0.14) in L1-L4 and from 0.702 (0.349-0.997, IQR: 0.125) to 0.745 (0.508-1.008, IQR: 0.137) in femur area at the 24th month of treatment. An improvement of 8.04% in L1-L4 BMD and 4.5% in femur neck BMD levels at the 24th month of treatment was observed. There was a significant decrease in bone turnover markers at the 24th month of treatment.

CONCLUSION

In our group of patients under denosumab treatment, 53% of persistence was found at 24 months and associated with improvement in BMD levels without any significant side effects except one case with urticarial reaction. Denosumab leads to improvements in BMD levels and is a well-tolerated agent in a real-life setting comparable to results of randomized controlled studies in patients with different comorbidities.

Changes in dual energy X-ray absorptiometry parameters in postmenopausal women with osteoporosis who received at least 12 months of denosumab treatment

Background/Aim: Denosumab is a human monoclonal antibody that binds to the receptor-activated nuclear factor kappa beta ligand (RANKL). Densosumab leads to a reduction in bone resorption by inhibiting RANKL and has been approved for treating postmenopausal osteoporosis (OP). The present study investigated real life data by evaluating the demographic data of postmenopausal patients with OP who received denosumab treatment and the changes in dual energy x-ray absorptiometry (DEXA) parameters before and after denosumab treatment. Methods: This retrospective cohort study included 49 postmenopausal female patients followed in our OP outpatient clinic who were treated with 60 mg subcutaneous denosumab every six months for at least 12 months. The study retrospectively analyzed and recorded patient age, body mass index, age of menopause, fracture history, antiresorptive and/or anabolic drug treatment history, and pre- and post-denosumab T-scores in addition to L1–4, femoral neck, and total hip bone mineral densities (BMDs) on DEXA scans. The changes that occurred before and after the treatment in addition to those that occurred after the treatment based on whether previous anabolic or antiresorptive agents had been used were statistically compared. Results: The L1–4 and total hip T-scores and L1–4 and total hip BMD values measured prior to denosumab treatment showed a statistically significant increase after denosumab treatment (P < 0.001, P = 0.002, P = 0.028, and P = 0.002, respectively). No statistically significant changes in the femoral neck T-score and BMD after denosumab treatment compared to that before denosumab use (P = 0.056 and P = 0.138, respectively) were found. Furthermore, no statistically significant difference between the pre- and post-denosumab DEXA parameters in the patients who used antiresorptive agents and those who did not (P > 0.05) was found. Additionally, pre- and post-denosumab parameters were not statistically significantly different between those who received and did not receive anabolic therapy before denosumab (P > 0.05). Conclusion: Denosumab treatment for postmenopausal OP leads to a significant increase in lumbar and total hip T-scores and BMDs.

Real-world effectiveness of osteoporosis treatments in Germany

This observational study assessed the impact on the fracture incidence of osteoporosis medications in postmenopausal women in Germany. Continued treatment with osteoporosis medications was associated with reductions of fracture rates in a real-world setting.

PURPOSE

The efficacy of osteoporosis medications has been demonstrated in clinical trials, but a lack of evidence exists of their real-world effectiveness. This real-world study assessed the treatment patterns and impact on the fracture incidence of osteoporosis medications in postmenopausal women in Germany.

METHODS

This cohort study used data from the WIG2 benchmark database, a German anonymised healthcare claims database. All women ≥ 50 years of age with ≥ 1 prescription for osteoporosis medication between 1 January 2013 and 31 December 2017 were included. The primary outcome was treatment effectiveness, evaluated as the change in fracture incidence after initiating treatment. Fracture types included all fractures, clinical vertebral, hip and wrist/forearm. Fracture incidence was assessed during the early-treatment period (0-3 months) and the on-treatment period (4-12, 13-24, 25-36 and 37-48 months).

RESULTS

Baseline covariates and treatment patterns were determined for 41,861 patients. The median duration of therapy was longer with denosumab (587 days) than with intravenous ibandronate (451 days), intravenous zoledronate (389 days) or oral bisphosphonates (258 days). The baseline incidence rate of all fractures was higher in patients receiving denosumab than in those receiving other treatments (87.6, 78.2, 56.6 and 66.0 per 1000 person-years for denosumab, oral bisphosphonates, intravenous ibandronate and intravenous zoledronate, respectively). Rates of all fractures declined with continued denosumab (by 38%, 50%, 56% and 67% at 12, 24, 36 and 48 months, respectively) and oral bisphosphonates (by 39%, 44%, 49% and 42%, respectively) treatment.

CONCLUSION

Continued treatment with osteoporosis medications was associated with reductions of fracture rates in a real-world setting.

A Rare Case of an Intertrochanteric Hip Fracture Combined with an Ipsilateral Incomplete Atypical Femoral Fracture Treated with a Long Gamma Intramedullary Nail

Introduction

Osteoporotic hip fractures can occur at the femoral neck and intertrochanteric area, with the peritrochanteric fracture being responsible for half of these fractures in the geriatric population. Atypical femoral fractures have been associated in the literature with long-term use of bisphosphonates or denosumab. However, few cases with the characteristics of these fractures have been reported in the past in patients not receiving antiresorptive drugs. To date, no combination of an intertrochanteric fracture with an impending incomplete atypical fracture of the ipsilateral femoral diaphysis has been previously reported in the literature.

Case Report

We present a rare case of a 97-year-old female patient with an intertrochanteric femoral fracture, with a preexisting focal cortical thickening along the lateral aspect of the ipsilateral proximal femoral diaphysis which is a warning sing for an incomplete atypical femoral fracture. A long gamma nail was used to fix the intertrochanteric fracture and simultaneously to stabilize and protect the area of the atypical femoral fracture.

Conclusion

Any patient with a peritrochanteric hip fracture who was under long-term treatment with antiresorptive agents against osteoporosis, or has other risk factors predisposing to atypical femoral fracture, should undergo a thorough radiological examination of the ipsilateral femur, to exclude the possibility of simultaneous presence of both of the above pathologies. In any such case, the use of a long hip cephalomedullary nail seems to be the best treatment option, because it can treat both fractures at the same time.

Assessment of Strategies for Safe Drug Discontinuation and Transition of Denosumab Treatment in PMO—Insights From a Mechanistic PK/PD Model of Bone Turnover

Denosumab (Dmab) treatment against postmenopausal osteoporosis (PMO) has proven very efficient in increasing bone mineral density (BMD) and reducing the risk of bone fractures. However, concerns have been recently raised regarding safety when drug treatment is discontinued. Mechanistic pharmacokinetic-pharmacodynamic (PK-PD) models are the most sophisticated tools to develop patient specific drug treatments of PMO to restore bone mass. However, only a few PK-PD models have addressed the effect of Dmab drug holidays on changes in BMD. We showed that using a standard bone cell population model (BCPM) of bone remodelling it is not possible to account for the spike in osteoclast numbers observed after Dmab discontinuation. We show that inclusion of a variable osteoclast precursor pool in BCPMs is essential to predict the experimentally observed rapid rise in osteoclast numbers and the associated increases in bone resorption. This new model also showed that Dmab withdrawal leads to a rapid increase of damage in the bone matrix, which in turn decreases the local safety factor for fatigue failure. Our simulation results show that changes in BMD strongly depend on Dmab concentration in the central compartment. Consequently, bone weight (BW) might play an important factor in calculating effective Dmab doses. The currently clinically prescribed constant Dmab dose of 60 mg injected every 6 months is less effective in increasing BMD for patients with high BW (2.5% for 80 kg in contrast to 8% for 60 kg after 6 years of treatment). However, bone loss observed 24 months after Dmab withdrawal is less pronounced in patients with high BW (3.5% for 80kg and 8.5% for 60 kg). Finally, we studied how to safely discontinue Dmab treatment by exploring several transitional and combined drug treatment strategies. Our simulation results indicate that using transitional reduced Dmab doses are not effective in reducing rapid bone loss. However, we identify that use of a bisphosphonate (BP) is highly effective in avoiding rapid bone loss and increase in bone tissue damage compared to abrupt withdrawal of Dmab. Furthermore, the final values of BMD and damage were not sensitive to the time of administration of the BP.

HDAC inhibitor quisinostat prevents estrogen deficiency-induced bone loss by suppressing bone resorption and promoting bone formation in mice

Postmenopausal osteoporosis (PMOP) is a metabolic skeletal disorder characterized by reduced bone mass and impaired bone microarchitecture resulting in increased bone fragility and fracture risk. PMOP is primarily caused by excessive osteoclastogenesis induced by estrogen deficiency. Quisinostat (Qst) is a potent hydroxamate-based second-generation inhibitor of histone deacetylases (HDACs) that can inhibit osteoclast differentiation in vitro, and protect mice from titanium particle-induced osteolysis in vivo. However, whether Qst has therapeutic potential against PMOP remains unclear. In the present study, we evaluated the therapeutic efficacy of Qst on PMOP, using a murine model of ovariectomy (OVX)-induced osteoporosis. We examined the body weight, femur length, and histology of major organs, and showed that Qst did not cause obvious toxicity in mice. Micro-computed tomography and histological analyses revealed that Qst treatment prevented OVX-induced trabecular bone loss both in femurs and vertebrae. Moreover, ELISA showed that Qst decreased the serum levels of the osteoclastic bone resorption marker CTX-1, whereas increased the levels of the osteoblastic bone formation marker Osteocalcin in OVX mice. Consistent with the CTX-1 results, TRAP staining showed that Qst suppressed OVX-induced osteoclastogenesis. Mechanistically, we showed that Qst suppressed RANKL-induced osteoclast differentiation in part by inhibiting p65 nuclear translocation. Collectively, our results demonstrated that Qst can ameliorate estrogen deficiency-induced osteoporosis by inhibiting bone resorption and promoting bone formation in vivo. In summary, our study provided the first preclinical evidence to support Qst as a potential therapeutic agent for PMOP prevention and treatment.

Bone Mineral and Organic Properties in Postmenopausal Women Treated With Denosumab for Up to 10 years

In postmenopausal women with osteoporosis, denosumab (DMAb) therapy through 10 years resulted in significantly higher degree of mineralization of bone, with a subsequent increase from years 2-3 to year 5 and no further difference between years 5 and 10. Our aim was to assess the variables reflecting the quality of bone mineral and organic matrix (Fourier transform infrared microspectroscopy), and the microhardness of bone (Vickers microindentation). Cross-sectional assessments were performed in blinded fashion on iliac bone biopsies from osteoporotic women (72 from FREEDOM trial, 49 from FREEDOM Extension trial), separately in cortical and cancellous compartments. After 2-3 years of DMAb, mineral/matrix ratio and microhardness of cortical bone were significantly higher compared with placebo, whereas mineral maturity, mineral crystallinity, mineral carbonation, and collagen maturity were not different in both bone compartments. Through 5 years of DMAb, mineral carbonation was significantly lower and mineral/matrix ratio, mineral maturity, and crystallinity were significantly higher versus 2-3 years and were not different between 5 and 10 years, with the exception of mineral maturity in cancellous bone. These data support a transition of mineral to more mature crystals (within physiological range) and the completeness of secondary mineralization within 5 years of DMAb treatment. Microhardness in cortical and cancellous compartments was significantly lower at 5 years of DMAb versus 2-3 years and was not different from years 5 to 10. The lower microhardness at years 5 and 10 is likely the result of maturation of the organic matrix in a persistently low state of bone remodeling over 5 and 10 years. © 2022 American Society for Bone and Mineral Research (ASBMR).

Roles of the RANKL-RANK Axis in Immunity-Implications for Pathogenesis and Treatment of Bone Metastasis

A substantial amount patients with cancer will develop bone metastases, with 70% of metastatic prostate and breast cancer patients harboring bone metastasis. Despite advancements in systemic therapies for advanced cancer, survival remains poor for those with bone metastases. The interaction between bone cells and the immune system contributes to a better understanding of the role that the immune system plays in the bone metastasis of cancer. The immune and bone systems share various molecules, including transcription factors, signaling molecules, and membrane receptors, which can stimulate the differentiation and activation of bone-resorbing osteoclasts. The process of cancer metastasis to bone, which deregulates bone turnover and results in bone loss and skeletal-related events (SREs), is also controlled by primary cancer-related factors that modulate the intratumoral microenvironment as well as cellular immune process. The nuclear factor kappa B ligand (RANKL) and the receptor activator of nuclear factor kappa B (RANK) are key regulators of osteoclast development, bone metabolism, lymph node development, and T-cell/dendritic cell communication. RANKL is an osteoclastogenic cytokine that links the bone and the immune system. In this review, we highlight the role of RANKL and RANK in the immune microenvironment and bone metastases and review data on the role of the regulatory mechanism of immunity in bone metastases, which could be verified through clinical efficacy of RANKL inhibitors for cancer patients with bone metastases. With the discovery of the specific role of RANK signaling in osteoclastogenesis, the humanized monoclonal antibody against RANKL, such as denosumab, was available to prevent bone loss, SREs, and bone metastases, providing a unique opportunity to target RANKL/RANK as a future strategy to prevent bone metastases.

Kidney Function Change and All-Cause Mortality in Denosumab Users with and without Chronic Kidney Disease

Denosumab is approved for osteoporosis treatment in subjects with and without chronic kidney disease (CKD). Confirmation is required for its safety, treatment adherence, renal function effect, and mortality in patients with CKD. A retrospective cohort study was conducted to compare new users of denosumab in terms of their two-year drug adherence in all participants (overall cohort) and CKD participants (CKD subcohort), which was defined as baseline estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m². The eGFR was calculated using the 2021 CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation. We defined high adherence (HA) users as receiving three or four doses and low adherence (LA) users as receiving one or two doses. All-cause mortality was analyzed using Kaplan–Meier curves and Cox regression models. In total, there were 1142 subjects in the overall cohort and 500 subjects in the CKD subcohort. HA users had better renal function status at baseline than LD users in the overall cohort. A decline in renal function was only observed among LD users in the overall cohort. In the CKD subcohort, no baseline renal function difference or renal function decline was demonstrated. The all-cause mortality rate of HA users was lower than LA users in both the overall cohort and CKD. A randomized control trial is warranted to target this unique population to confirm our observations.

Long-term persistence with denosumab: real-world data from the Austrian Osteoporosis Clinic (AOC). A retrospective data analysis

In short-term studies, persistence with denosumab has been higher than with other osteoporosis drugs. This study shows that persistence can be maintained in the long-term and is associated with efficacy and safety parameters.

PURPOSE

To assess long-term persistence with denosumab in postmenopausal women with osteoporosis. Secondary purposes were the evaluation of changes in efficacy and tolerance/safety parameters over time.

METHODS

Persistence was determined by number and rate of patients receiving denosumab on time in 6-month intervals (+ / - 8 weeks). The total population was stratified by internal patients (injections and monitoring at the Austrian Osteoporosis Clinic [AOC], 74%) and external patients (injections at the practitioner's office with occasional monitoring at the AOC, 26%). In internal patients, efficacy parameters including bone mineral density (BMD) and the bone marker CTX were assessed at fixed time points and tolerance/safety parameters including side effects (SEs), adverse events (AEs), and serious AEs (SAEs) evaluated.

RESULTS

Of 851 patients, 71% (73% internal and 64% external) were persistent at 7.5 years of follow-up. The mean rate of cumulative persistence in internal patients decreased from 94% at the time of the second dose to 73% at the time of the fifteenth dose. BMD increased and CTX decreased, overall and in pairwise comparisons (all p < .001). AEs and SAEs, but not SEs, were lower in persistent than non-persistent patients.

CONCLUSIONS

This is the first study showing that long-term (> 3 years) real-world persistence with denosumab could be maintained at a high level (> 70%) in most patients. Denosumab was well tolerated and associated with decreased CTX levels and increased BMD.

AGN1 implant material to treat bone loss: Resorbable implant forms normal bone with and without alendronate in a canine critical size humeral defect model

BACKGROUND

Fractures secondary to osteoporosis, particularly those of the hip and spine, are a major public health concern with high social and economic costs. The Local Osteo-Enhancement Procedure (LOEP) is an approach intended to strengthen skeletal areas that are at the highest risk for fracture due to osteoporosis. LOEP involves the implantation of AGN1, a triphasic, calcium-based, osteoconductive material which is then resorbed and replaced by bone. Since alendronate is the most prescribed osteoporotic treatment, the purpose of this canine study is to determine if the newly formed bone has the same properties as normal bone and whether alendronate treatment impacts AGN1 resorption and replacement with bone.

METHODS

Sixty skeletally mature male hounds (24-38 kg) were evenly divided between alendronate (0.2 mg/kg/day) and non-alendronate treatment groups. A critical-size core bone defect created in one proximal humerus was implanted with AGN1 while the contralateral non-operated humerus served as a paired control in each animal. Animals were sacrificed 13, 26, and 52 weeks post-operatively (10 per treatment per timepoint). The control and treatment site bone specimens from each animal were examined using radiographic, histomorphometric, and biomechanical techniques. Results between alendronate-treated and non-alendronate-treated animals were compared as groups.

RESULTS

AGN1 implant material was consistently resorbed and replaced by bone in all animals. At 52 weeks, only minimal residual implant material could be detected (0.9 ± 2.3% non-alendronate group; 2.2 ± 3.1% alendronate group), and new bone filled the defects in both the non-alendronate and alendronate groups. At 13 and 26 weeks, microCT revealed the newly formed bone in the defects had significantly higher trabecular bone volume and number connectivity than control bone in both groups. Mechanical testing demonstrated that the new bone had ultimate compressive strength and modulus equivalent to control bone as early as 13 weeks post-surgery which was maintained to 52 weeks in both groups.

CONCLUSIONS

In this canine critical-sized humeral core defect model, AGN1 was progressively replaced by normal bone as evaluated by all outcome measures. Concurrent alendronate therapy did not significantly impact AGN1 resorption or new bone formation. These results demonstrate that AGN1 can be used in conjunction with alendronate in non-osteoporotic animals.

CLINICAL RELEVANCE

This study suggests that the AGN1 implant material demonstrates potential for local restoration of bone in critical-size core defects, and that the material is compatible with alendronate drug therapy. Further studies will be required to determine if these results apply to other osteoporosis medications.

The osteocyte as a signaling cell

Osteocytes, former osteoblasts encapsulated by mineralized bone matrix, are far from being passive and metabolically inactive bone cells. Instead, osteocytes are multifunctional and dynamic cells capable of integrating hormonal and mechanical signals and transmitting them to effector cells in bone and in distant tissues. Osteocytes are a major source of molecules that regulate bone homeostasis by integrating both mechanical cues and hormonal signals that coordinate the differentiation and function of osteoclasts and osteoblasts. Osteocyte function is altered in both rare and common bone diseases, suggesting that osteocyte dysfunction is directly involved in the pathophysiology of several disorders affecting the skeleton. Advances in osteocyte biology initiated the development of novel therapeutics interfering with osteocyte-secreted molecules. Moreover, osteocytes are targets and key distributors of biological signals mediating the beneficial effects of several bone therapeutics used in the clinic. Here we review the most recent discoveries in osteocyte biology demonstrating that osteocytes regulate bone homeostasis and bone marrow fat via paracrine signaling, influence body composition and energy metabolism via endocrine signaling, and contribute to the damaging effects of diabetes mellitus and hematologic and metastatic cancers in the skeleton.

The therapeutic potential of mesenchymal stem cells in treating osteoporosis

Osteoporosis (OP), a common systemic metabolic bone disease, is characterized by low bone mass, increasing bone fragility and a high risk of fracture. At present, the clinical treatment of OP mainly involves anti-bone resorption drugs and anabolic agents for bone, but their long-term use can cause serious side effects. The development of stem cell therapy and regenerative medicine has provided a new approach to the clinical treatment of various diseases, even with a hope for cure. Recently, the therapeutic advantages of the therapy have been shown for a variety of orthopedic diseases. However, these stem cell-based researches are currently limited to animal models; the uncertainty regarding the post-transplantation fate of stem cells and their safety in recipients has largely restricted the development of human clinical trials. Nevertheless, the feasibility of mesenchymal stem cells to treat osteoporotic mice has drawn a growing amount of intriguing attention from clinicians to its potential of applying the stem cell-based therapy as a new therapeutic approach to OP in the future clinic. In the current review, therefore, we explored the potential use of mesenchymal stem cells in human OP treatment.

Interstitial Lung Disease in a Woman with Rheumatoid Arthritis Treated with Denosumab: A Case Report

The present report describes the case of an 84-year-old female Japanese patient with rheumatoid arthritis (RA) who experienced exacerbation of interstitial lung disease (ILD) after denosumab (Dmab) treatment. The onset of RA occurred in 2008, and the patient had been treated with intravenous or subcutaneous injection of tocilizumab (TCZ) since 2009. In July 2013, she experienced a lumbar vertebral fracture and began treatment with 60-mg Dmab injection every 6 months in January 2014. The patient had a history of mild ILD and was evaluated for ILD by chest computed tomography (CT) imaging prior to the start of Dmab use. The vertebral fracture did not recur after the initiation of Dmab treatment, and her osteoporosis was successfully treated. However, she expressed a concern of exacerbations of cough and respiratory discomfort that had occurred since September 2019. The chest CT image in November 2015 showed minor ILD progression, whereas the image in September 2019 showed severe exacerbation of ILD. To treat this exacerbation, 10 mg of methylprednisolone (mPSL) and 2.5 mg of tacrolimus (TAC) were administered, and Dmab was discontinued. The patient was subsequently switched to oral bisphosphonate. The patient's respiratory discomfort and the finding of interstitial lung lesion in CT imaging improved after Dmab discontinuation. This case showed that exacerbation of ILD may occur after Dmab treatment, and physicians should consider the risks of Dmab-related ILD in patients with RA complicated by ILD.

The Effects of Osteoporotic and Non-osteoporotic Medications on Fracture Risk and Bone Mineral Density

Osteoporosis is a highly prevalent bone disease affecting more than 37.5 million individuals in the European Union (EU) and the  United States of America (USA). It is characterized by low bone mineral density (BMD), impaired bone quality, and loss of structural and biomechanical properties, resulting in reduced bone strength. An increase in morbidity and mortality is seen in patients with osteoporosis, caused by the approximately 3.5 million new osteoporotic fractures occurring every year in the EU. Currently, different medications are available for the treatment of osteoporosis, including anti-resorptive and osteoanabolic medications. Bisphosphonates, which belong to the anti-resorptive medications, are the standard treatment for osteoporosis based on their positive effects on bone, long-term experience, and low costs. However, not only medications used for the treatment of osteoporosis can affect bone: several other medications are suggested to have an effect on bone as well, especially on fracture risk and BMD. Knowledge about the positive and negative effects of different medications on both fracture risk and BMD is important, as it can contribute to an improvement in osteoporosis prevention and treatment in general, and, even more importantly, to the individual's health. In this review, we therefore discuss the effects of both osteoporotic and non-osteoporotic medications on fracture risk and BMD. In addition, we discuss the underlying mechanisms of action.

Effect of drugs on bone mineral density in postmenopausal osteoporosis: a Bayesian network meta-analysis

Background

Osteoporosis affects mostly postmenopausal women, leading to deterioration of the microarchitectural bone structure and low bone mass, with an increased fracture risk with associated disability, morbidity and mortality. This Bayesian network meta-analysis compared the effects of current anti-osteoporosis drugs on bone mineral density.

Methods

The present systematic review and network meta-analysis follows the PRISMA extension statement to report systematic reviews incorporating network meta-analyses of health care interventions. The literature search was performed in June 2021. All randomised clinical trials that have investigated the effects of two or more drug treatments on BMD for postmenopausal osteoporosis were accessed. The network comparisons were performed through the STATA Software/MP routine for Bayesian hierarchical random-effects model analysis. The inverse variance method with standardised mean difference (SMD) was used for analysis.

Results

Data from 64 RCTs involving 82,732 patients were retrieved. The mean follow-up was 29.7 ± 19.6 months. Denosumab resulted in a higher spine BMD (SMD −0.220; SE 3.379), followed by pamidronate (SMD −5.662; SE 2.635) and zoledronate (SMD −10.701; SE 2.871). Denosumab resulted in a higher hip BMD (SMD −0.256; SE 3.184), followed by alendronate (SMD −17.032; SE 3.191) and ibandronate (SMD −17.250; SE 2.264). Denosumab resulted in a higher femur BMD (SMD 0.097; SE 2.091), followed by alendronate (SMD −16.030; SE 1.702) and ibandronate (SMD −17.000; SE 1.679).

Conclusion

Denosumab results in higher spine BMD in selected women with postmenopausal osteoporosis. Denosumab had the highest influence on hip and femur BMD.

Level of evidence

Level I, Bayesian network meta-analysis of RCTs

Medical treatment of osteoporosis

Osteoporosis is a common chronic condition that markedly increases the risk of fractures. Osteoporotic-related fractures increase morbidity and mortality and impair quality of life. Therefore, a correct approach for fracture prevention seems mandatory. Lifestyle changes should be recommended to all patients, including weight reduction if patients are obese/overweight, increasing physical activity and avoiding alcohol consumption and smoking. Additionally, calcium and vitamin D3 should be prescribed until the vitamin D deficit is resolved. Osteoporosis treatment options mainly include antiresorptives (i.e. estrogens, selective estrogen receptor modulators, bisphosphonates, denosumab) and anabolic agents (i.e. teriparatide, abaloparatide, romosozumab). Although presenting differences in efficacy and side effects, they have all been shown to increase bone mineral density (BMD) and to reduce osteoporotic-related fractures. Monotherapy with antiresorptive agents, particularly oral bisphosphonates, should be considered routinely as the first option for treatment of postmenopausal women. However, in the case of side effects, therapeutic failure or the need for long-term use, anabolic agents may be considered. In high-risk patients, anabolic agents may be considered as an initial therapeutic option. The combination of antiresorptive and anabolic agents may be useful to increase BMD compared with monotherapy, but more information is warranted to determine the effects on fracture risk.

Analysis of bone architecture using fractal-based TX-Analyzer™ in adult patients with osteogenesis imperfecta

BACKGROUND

Osteogenesis imperfecta (OI) is a rare genetic disorder characterized by impaired bone quality and quantity. Established imaging techniques have limited reliability in OI. The TX-Analyzer™ is a new, fractal-based software allowing a non-invasive assessment of bone structure based on conventional radiographs. We explored whether the TX-Analyzer™ can discriminate OI patients and healthy controls. Furthermore, we investigated the correlation between TX-Analyzer™ parameters and (i) bone mineral density (BMD) by Dual Energy X-ray Absorptiometry (DXA), (ii) trabecular bone score (TBS), and (iii) bone microstructure by high-resolution peripheral quantitative computed tomography (HR-pQCT).

MATERIAL AND METHODS

Data of 29 adult OI patients were retrospectively analyzed. Standard radiographs of the thoracic and lumbar spine were evaluated using the TX-Analyzer™. Bone Structure Value (BSV), Bone Variance Value (BVV), and Bone Entropy Value (BEV) were measured at the vertebral bodies T7 to L5. Data were compared to a healthy, age- and gender-matched control group (n = 58). BMD by DXA, TBS, and trabecular bone microstructure by means of HR-pQCT were correlated to TX-Analyzer™ parameters in OI patients. The accuracy of the TX-Analyzer™ parameters in detecting OI was assessed with area under curve (AUC) analysis of receiver operating characteristic (ROC).

RESULTS

BEV of the thoracic and the lumbar spine were significantly lower in OI patients compared to controls (both p < 0.001). BEV of the thoracic spine was significantly correlated to TBS (ρ = 0.427, p = 0.042) as well as trabecular number (Tb.N) at the radius (ρ = 0.603, p = 0.029) and inhomogeneity of the trabecular network (Tb.1/N.SD) at the radius (ρ = -0.610, p = 0.027), when assessed by HR-pQCT. No correlations were found between BEV and BMD by DXA. BEV of the thoracic and the lumbar spine had an AUC of 0.81 (95% confidence interval [CI] 0.67-0.94, p < 0.001) and 0.73 (95% CI 0.56-0.89, p = 0.008), respectively. BSV and BVV did not differ between OI patients and controls.

CONCLUSION

The software TX-Analyzer™ is able to discriminate patients with OI from healthy controls. ROC curves of BEV values suggest a suitable clinical applicability. Low to no correlations with conventional methods suggest, that the TX-Analyzer™ may indicate a new and independent examination tool in OI.

Denosumab Discontinuation in Patients Treated for Low Bone Density and Osteoporosis

Denosumab (DMAB) is a potent antiresorptive treatment used for treatment of osteoporosis and low bone mineral density (BMD) in those at high risk for fracture. In postmenopausal women with osteoporosis, DMAB treatment for 10 years has been studied, with results showing continued gains in BMD, sustained fracture risk reduction, and low risk of adverse events. However, upon discontinuation of DMAB, there is a rapid reversal of effect, with increase in bone turnover, loss of BMD, and in a subset of patients, a greater risk for multiple vertebral fractures.

High persistence over two years with denosumab among postmenopausal women with osteoporosis in France: A prospective cohort study

PURPOSE

To assess the 12 and 24-month persistence with denosumab in postmenopausal women with osteoporosis in real-world clinical practice in France, and to describe characteristics and management of these patients.

METHODS

This prospective, multicenter cohort study evaluated persistence with denosumab at 12 months (primary endpoint) and 24 months (secondary endpoint), defined as at least 2 or 4 injections respectively, and time elapsed between 2 consecutive injections did not exceed 6 months +8 weeks. Other endpoints included patients' characteristics at baseline, medical history, concomitant and previous treatments, and incidence of adverse drug reactions (ADR), serious adverse events and fractures.

RESULTS

478 patients were enrolled by 86 physicians between June 2015 and February 2016. The mean follow-up was 28 months. Mean age was 72 years and 91% of patients had been previously treated for osteoporosis. The persistence with denosumab was 86% (95%CI: 83%-89%) at 12 months and 72% (95%CI: 68%-76%) at 24 months. Using the Kaplan-Meier estimates, the persistence probability over time was 86% at 12 months and 76% at 24 months. During the study, 78 patients discontinued therapy. No multiple vertebral fractures were reported upon discontinuation. ADR were reported for 55 patients, 4 being serious, and 27 patients discontinued denosumab due to an ADR. Among patients who received at least one injection, 10 died. None of the deaths were attributable to denosumab.

CONCLUSION

Persistence with denosumab at 12 and 24 months was high, and the treatment was well tolerated among postmenopausal women with osteoporosis treated in routine clinical practice in France.

Denosumab for the treatment of HIV-associated osteoporosis with fractures in a premenopausal woman

The prevalence of osteoporosis is about three times greater in people living with HIV than in the general population. Bisphosphonates are the only class of antiresorptive drugs which have proved to be safe and effective in HIV patients. However, bisphosphonates are not recommended in women of childbearing age due to an increased rate of associated neonatal complications. To the best of our knowledge no reports on the use of denosumab in HIV-infected individuals have been published so far. We describe a 38 year-old woman with HIV, osteoporosis and vertebral fractures treated with denosumab, a monoclonal antibody targeting RANKL. After four years of treatment, bone mineral density improved, no new fractures occurred, and neither HIV reactivation nor opportunistic infections were observed. We show that denosumab could be a safe and effective approach for osteoporosis in patients with HIV and could be considered in women of childbearing age.

Risk factors for vertebral fractures and bone loss after denosumab discontinuation: A real-world observational study

BACKGROUND

Denosumab discontinuation without subsequent bisphosphonates (BPs) is associated with bone loss and multiple vertebral fractures.

OBJECTIVE

Identifying risk factors for bone loss and vertebral fractures after denosumab discontinuation.

METHODS

This retrospective study measured the outcome of 219 women with osteoporosis who discontinued denosumab treatment and received subsequent treatment with zoledronate, other BPs or a selective estrogen receptor modulator (SERM), or no therapy. Fracture rate, longitudinal bone mineral density (BMD) changes and bone turnover markers (BTMs) within 2 years after denosumab discontinuation were analysed. Linear regression analysis evaluated loss of BMD and age, BMI (kg/m²), denosumab treatment duration, pre-treatment, prior fracture state, baseline T-scores, use of glucocorticoids or aromatase inhibitors and BMD gains under denosumab therapy.

RESULTS

171 women received zoledronate after denosumab discontinuation, 26 had no subsequent treatment and 22 received other therapies (other BPs or a SERM). Zoledronate was associated with the fewest vertebral fractures (hazard ratio 0.16, p = 0.02) and all subsequent therapies retained BMD at all sites to some extent. Higher BMD loss was associated with younger age, lower BMI, longer denosumab treatment, lack of prior antiresorptive treatment and BMD gain under denosumab treatment. BTM levels correlated with denosumab treatment duration and bone loss at the total hip, but not the lumbar spine.

CONCLUSIONS

Compared to no subsequent therapy, zoledronate was associated with fewer vertebral fractures after denosumab. Further, BMD loss depended on denosumab treatment duration, age, prior BP therapy and BMD gain under denosumab therapy, whereas BTM levels were associated with bone loss at the total hip and denosumab treatment duration.

Efficacy of Denosumab Therapy Following Treatment with Bisphosphonates in Women with Osteoporosis: A Cohort Study

Denosumab is a human monoclonal antibody that neutralizes RANKL, a cytokine able to interact with the RANK receptor on preosteoclasts and osteoclasts, decreasing their recruitment and differentiation, leading to a decreased bone resorption. The aim of this observational real-life study was to analyze adherence to denosumab therapy and assess its efficacy in increasing bone mineral density (BMD) and modulating biochemical skeletal markers following previous treatments with bisphosphonates in a group of post-menopausal women with osteoporosis. Women were recruited in the specialized center from March 2012 to September 2019. Biochemical markers were recorded at baseline and every six months prior to subsequent drug injection. Dual X-ray absorptiometry was requested at baseline and after 18/24 months. Comparing BMD at baseline and after denosumab therapy in naive patients and in those previously treated with bisphosphonates, a positive therapeutic effect was observed in both groups. The results of our real-life study demonstrate, as expected, that BMD values significantly increased upon denosumab treatment. Interestingly, denosumab showed an increased efficacy in patients previously treated with bisphosphonates. Moreover, biochemical markers data indicate that osteoporotic patients, without other concomitant unstable health conditions, could be evaluated once a year, decreasing the number of specialistic center access.

Pharmacological Management of Postmenopausal Osteoporosis: a Level I Evidence Based - Expert Opinion

Objectives: Postmenopausal osteoporosis carries a high risk of fractures, which decrease quality of life and are associated with high morbidity, mortality, and economic burden. The best pharmacological treatment options to manage and prevent osteoporotic fractures remain still unclear. The present study investigated the efficacy and safety of the most commonly employed drugs in the management of postmenopausal osteoporosis. Methods: Only RCTs comparing different drugs for the management of postmenopausal osteoporosis were included. Data from 76 RCTs (205,011 patients) were collected. The mean follow-up was 27.6 ± 14.9 months. Results: Denosumab reported the lowest rate of non-vertebral fractures (LOR -1.57), Romosozumab the lowest rate of vertebral fractures (LOR 1.99), and Ibandronate the lowest rate of hip fractures (LOR0.18). Serious adverse events resulted in the lowest in the Raloxifene group (LOR 3.11), while those leading to study discontinuation were lowest in the Romosozumab cohort (LOR 2.65). Conclusions: Denosumab resulted in most effective, particularly in reducing the occurrence of non-vertebral fractures. Romosozumab and Ibandronate resulted best to prevent, respectively, vertebral fractures and hip fractures. Adverse events leading to study discontinuation were less frequent in the Romosozumab and Denosumab groups, while Raloxifene and Alendronate showed a lower incidence of serious adverse events overall. Level of evidence: I, Bayesian network meta-analysis of RCTs.

The Effect of Teriparatide for the Treatment of Multiple Spontaneous Clinical Vertebral Fractures after Discontinuation of Denosumab in a Female Patient with Rheumatoid Arthritis: A Case Report

Discontinuation of denosumab is associated with the risk of rebound in bone turnover and rebound-associated spontaneous clinical vertebral fractures. This case report presents an 86-year-old woman with rheumatoid arthritis who experienced rebound-associated spontaneous clinical vertebral fractures at 9 months after denosumab discontinuation. Following 5-year bisphosphonate treatment, the patient had 9 injections of 60-mg denosumab every 6 months. Because of tooth extraction, denosumab treatment was discontinued, and raloxifene was administered. At 9 months after the last denosumab injection, the patient experienced severe low back pain. Magnetic resonance imaging (MRI) and radiograph demonstrated clinical fracture at the fourth lumbar vertebra. MRI performed at 3 months after first fracture showed two additional fractures at the second and third lumbar vertebrae. Teriparatide was administered for management of rebound-associated spontaneous clinical, multiple vertebral fractures. Teriparatide was effective for accelerating the fracture healing and suppressing the occurrence of new fractures. However, 2-year treatment of teriparatide did not have suppressive effect of rebound in bone turnover and general bone loss. This case suggested that teriparatide was effective for suppression of new rebound-associated spontaneous clinical vertebral fractures, but not effective in prevention of general bone loss after denosumab discontinuation.

Should denosumab treatment for osteoporosis be continued indefinitely?

Denosumab was approved for the treatment of postmenopausal osteoporosis in 2010, based on the FREEDOM study, which indicated a benefit in terms of increased bone mineral density and reduced risk of major osteoporotic fracture. In the initial clinical studies it was noted that discontinuation of denosumab can lead to a rebound of bone turnover markers and loss of accrued bone mineral density. An increased risk of fractures (multiple vertebral fractures in particular) associated with discontinuation was noted after approval and marketing of denosumab. For many patients experiencing gain in bone mineral density and fracture prevention while taking denosumab, there is no reason to stop therapy. However, discontinuation of denosumab may happen due to non-adherence; potential lack of efficacy in an individual; where reimbursement for therapy is limited to those with bone mineral density in the osteoporosis range, when assessment reveals this has been exceeded; or patient or physician concern regarding side effects. This review paper aims to discuss these concerns and to summarize the data available to date regarding sequential osteoporosis therapy following denosumab cessation to reduce the risk of multiple vertebral fracture.

Relationship Between Bone Mineral Density and Risk of Vertebral Fractures with Denosumab Treatment in Japanese Postmenopausal Women and Men with Osteoporosis

In this post hoc analysis of the Denosumab Fracture Intervention Randomized Placebo-Controlled Trial (DIRECT) in Japanese postmenopausal women and men with osteoporosis, we evaluated the relationship between vertebral fracture risk and both bone mineral density (BMD) T-score and percent change after 24 months of denosumab treatment at total hip, femoral neck, and lumbar spine. Logistic regression analysis was performed and the proportion of treatment effect explained by BMD in vertebral fracture risk was estimated. The results demonstrate that both total hip BMD T-score and change can be strong predictors of subsequent fracture risk, and that total hip BMD change explained 73%, while T-score explained 23%, of the treatment effect. In contrast, neither femoral neck BMD change nor T-score can predict the effect of denosumab on vertebral fracture risk. Furthermore, although lumbar spine BMD T-score was associated with vertebral fracture incidence, lumbar spine BMD change was inversely related to vertebral fracture risk. Because there was no relationship between lumbar spine BMD change and T-score at 24 months of denosumab treatment, and because there can be small undetectable vertebral deformities that may increase BMD values, these results suggest that lumbar spine BMD change is not a good surrogate for vertebral fracture risk assessment. It is suggested that both total hip BMD change and T-score can be good surrogates for predicting vertebral fracture risk in Japanese patients with osteoporosis under denosumab treatment.ClinicalTrials.gov identifier: NCT00680953.

Bone Health and Osteoporosis Prevention and Treatment

Postmenopausal osteoporosis is a common condition and is associated with increased risk of fracture, including hip and vertebral fractures that in turn can have devastating consequences on morbidity and mortality. In this article, we review the pathogenesis and diagnostic approach to postmenopausal osteoporosis. We review available nonpharmacologic and pharmacologic therapies and we discuss their clinical efficacy and complications, with a detailed discussion of atypical femur fractures and osteonecrosis of the jaw.

Treatment of postmenopausal osteoporosis with bone-forming and antiresorptive treatments: Combined and sequential approaches

Efficient therapies are available for the treatment of osteoporosis. Bisphosphonates and denosumab are the most commonly used antiresorptive therapies. Despite differences in the increase in bone mineral density seen with these drugs, the reductions in fracture risk are similar; 50-70%, 20%, and 40% for vertebral, non-vertebral and hip fractures, respectively. The bone-forming treatments; teriparatide and abaloparatide increase bone mineral density more than the antiresorptives and the reductions in fracture risk are 85% and 40-50% for vertebral and non-vertebral fractures, respectively, compared to placebo. The VERO study demonstrated a >50% reduction in vertebral and clinical fractures in women treated with teriparatide compared to risedronate. The dual-action treatment; romosozumab leads to more pronounced increases in BMD than other treatment modalities and reduces the risk of vertebral and clinical fractures by 73% and 36% compared to placebo after 12 months and the sequential treatment regime; romosozumab for 12 months followed by alendronate reduced the risk of vertebral, non-vertebral and hip fractures by 48%, 20% and 38%, respectively compared to alendronate after 2-3 years. The evidence for combination therapy targeting both resorption and formation is limited as only short-term studies with BMD as the endpoint have been performed. All bone-forming and dual-action treatments increase BMD and reduce the fracture risk, however, the effect wears off with time and treatment is therefore only temporary and should be followed by antiresorptive treatment with a bisphosphonate or denosumab. The sequence of treatment matters as the BMD response to teriparatide is reduced in patients previously treated with bisphosphonates; however, based on the findings of the VERO trial, the anti-fracture efficacy of bone-forming treatment in comparison with risedronate seems to be preserved after bisphosphonate therapy. The DATA study suggested that transitioning from denosumab to teriparatide is problematic due to the increase in bone resorption occurring after stopping denosumab. Studies have shown further improvements in BMD when transitioning from oral bisphosphonates to zoledronic acid or denosumab. Management of osteoporosis will in many patients include a long-term treatment plan. This will often include sequential therapy which in severe cases preferably should start with bone-forming followed by antiresorptive treatment. The severity of osteoporosis, reaching a treatment goal, and responding to treatment failure are important factors determining the treatment sequence in the individual patient.

A Review on the Role of Denosumab in Fracture Prevention

Denosumab is a receptor activator of nuclear factor kappa-Β ligand inhibitor, which suppresses the bone resorption process to preserve bone mass. It is usually recommended to postmenopausal women and men with high fracture risk. With the recent publication of the results from FREEDOM study and its extension, the long-term effect of denosumab in preventing fragility fractures has been put forward. This review aims at summarising the evidence of denosumab in reducing fracture risk and its safety derived from clinical studies. Most of the evidence are derived from FREEDOM trials up to 10 years of exposure. Denosumab is reported to prevent vertebral and non-vertebral fractures. It is also proven effective in Japanese women, patients with chronic kidney diseases and breast cancer patients receiving antineoplastic therapy. Denosumab discontinuation leads to high remodeling, loss of bone mineral density and increased fracture risk. These negative effects might be preventable by bisphosphonate treatment. The safety profile of denosumab is consistent with increased years of exposure. In conclusion, denosumab is a safe and effective option for reducing fracture risk among patients with osteoporosis.

Atypical Subtrochanteric Femur Fracture and Hip Osteoarthritis Treated with a Revision Monoblock Stem and Strut Allograft: A Case Report

CASE

A 73-year-old woman was diagnosed with a nondisplaced incomplete atypical bisphosphonate-related subtrochanteric femur fracture and ipsilateral hip osteoarthritis. She was treated with a total hip arthroplasty using a monoblock revision stem and a strut allograft to provide adjunctive mechanical and biological support. At the final follow-up, the patient had no pain, the stem was well fixed, and the allograft strut had incorporated; however, a persistent fracture line was noted.

CONCLUSION

When an atypical femur fracture coexists with hip osteoarthritis, total hip arthroplasty may be a reasonable treatment option to address the fracture and concomitant hip osteoarthritis with a single surgical intervention. However, consideration should be given to using a stem with distal fixation and augmenting the construct with a strut allograft.