Bisphosphonate use and the risk of subtrochanteric or femoral shaft fractures in older women

Differences in tissue-level properties as assessed by nano-scratching in patients with and without atypical femur fractures on long-term bisphosphonate therapy: a proof-of-concept pilot study

Atypical femur fractures (AFFs) are a well-established complication of long-term bisphosphonate (BP) therapy, but their pathogenesis is not fully understood. Although many patients on long-term BP therapy have severe suppression of bone turnover (SSBT), not all such patients experience AFF, even though SSBT is a major contributor to AFF. Accordingly, we evaluated tissue level properties using nano-scratch testing of trans-iliac bone biopsy specimens in 12 women (6 with and 6 without AFF matched for age and race). Nano-scratch data were analyzed using a mixed-model ANOVA with volume-normalized scratch energy as a function of AFF (Yes or No), region (periosteal or endosteal), and a first-order interaction between region and AFF. Tukey post hoc analyses of the differences of least squared means of scratch energy were performed and reported as significant if p<.05. The volume-normalized scratch energy was 10.6% higher in AFF than in non-AFF patients (p=.003) and 17.9 % higher in the periosteal than in the endosteal region (p=.004). The differences in normalized scratch energy are suggestive of a higher hardness of the bone tissue after long-term BP therapy. The results of this study are consistent with other studies in the literature and demonstrate the efficacy of using Nano-Scratch technique to evaluate bone tissue that exhibits SSBT and AFF. Further studies using nano-scratch may help quantify and elucidate underlying mechanisms for the pathogenesis of AFF.

Bone Fragility in Diabetes and its Management: A Narrative Review

Bone fragility is a serious yet under-recognised complication of diabetes mellitus (DM) that is associated with significant morbidity and mortality. Multiple complex pathophysiological mechanisms mediating bone fragility amongst DM patients have been proposed and identified. Fracture risk in both type 1 diabetes (T1D) and type 2 diabetes (T2D) continues to be understated and underestimated by conventional risk assessment tools, posing an additional challenge to the identification of at-risk patients who may benefit from earlier intervention or preventive strategies. Over the years, an increasing body of evidence has demonstrated the efficacy of osteo-pharmacological agents in managing skeletal fragility in DM. This review seeks to elaborate on the risk of bone fragility in DM, the underlying pathogenesis and skeletal alterations, the approach to fracture risk assessment in DM, management strategies and therapeutic options.

Exploration of the Clinical Effect of Different Autotransfusion Methods on Patients With Femoral Shaft Fracture Surgery

OBJECTIVE

To explore the clinical effect of predeposit, salvage, and hemodilution autotransfusion on patients with femoral shaft fracture (FSF) surgery.

METHODS

Selected patients with FSF were randomly divided into three groups: intraoperative blood salvage autotransfusion, preoperative hemodilution autohemotransfusion, and predeposit autotransfusion. Five days after the operation, the body temperature, heart rate, blood platelet (PLT), and hemoglobin (Hb) of patients were determined. The concentrations of EPO and GM-CSF in the three groups were calculated by ELISA. The content of CD14+ monocytes was calculated by FCM assay. The growth time and condition of the patient's callus were determined at the 30th, 45th, and 60th day after operation. Cox regression analysis was used to analyze the correlation between EPO, GM-CSF, CD14+ mononuclear content, callus growth, and autotransfusion methods.

RESULTS

There were no statistically significant differences in body temperature and heart rate between the three groups (p > 0.05). PLT and Hb in the Predeposit group were markedly increased compared with that in the Salvage and Hemodilution groups. The concentrations of EPO and GM-CSF in the Predeposit group were markedly increased compared with that in the Salvage and Hemodilution groups. The content of CD14+ monocytes in the Predeposit group was significantly higher than that in the Salvage and Hemodilution groups. Predeposit autotransfusion promotes callus growth more quickly.

CONCLUSION

Predeposit autotransfusion promoted the recovery of patients with FSF after the operation more quickly than salvage autotransfusion and hemodilution autotransfusion.

Anti-Siglec-15 Antibody Prevents Marked Bone Loss after Acute Spinal Cord Injury-Induced Immobilization in Rats

Rapid and extensive sublesional bone loss after spinal cord injury (SCI) is a difficult medical problem that has been refractory to available interventions except the antiresorptive agent denosumab (DMAB). While DMAB has shown some efficacy in inhibiting bone loss, its concurrent inhibition of bone formation limits its use. Sialic acid-binding immunoglobulin-like lectin (Siglec)-15 is expressed on the cell surface of mature osteoclasts. Anti-Siglec-15 antibody (Ab) has been shown to inhibit osteoclast maturation and bone resorption while maintaining osteoblast activity, which is distinct from current antiresorptive agents that inhibit the activity of both osteoclasts and osteoblasts. The goal of the present study is to test a Siglec-15 Ab (NP159) as a new treatment option to prevent bone loss in an acute SCI model. To this end, 4-month-old male Wistar rats underwent complete spinal cord transection and were treated with either vehicle or NP159 at 20 mg/kg once every 2 weeks for 8 weeks. SCI results in significant decreases in bone mineral density (BMD, -18.7%), trabecular bone volume (-43.1%), trabecular connectivity (-59.7%), and bone stiffness (-76.3%) at the distal femur. Treatment with NP159 almost completely prevents the aforementioned deterioration of bone after SCI. Blood and histomorphometric analyses revealed that NP159 is able to greatly inhibit bone resorption while maintaining bone formation after acute SCI. In ex vivo cultures of bone marrow cells, NP159 reduces osteoclastogenesis while increasing osteoblastogenesis. In summary, treatment with NP159 almost fully prevents sublesional loss of BMD and metaphysis trabecular bone volume and preserves bone strength in a rat model of acute SCI. Because of its unique ability to reduce osteoclastogenesis and bone resorption while promoting osteoblastogenesis to maintain bone formation, Siglec-15 Ab may hold greater promise as a therapeutic agent, compared with the exclusively antiresorptive or anabolic agents that are currently used, in mitigating the striking bone loss that occurs after SCI or other conditions associated with severe immobilization. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Pertrochanteric hip fracture is associated with mobility decline and poorer physical performance 4 to 6 months post-hip fracture

BACKGROUND

To study the effect of hip fracture type on physical performance, functional ability and change in mobility four to six months after the injury.

METHODS

A total of 1331 patients out of consecutive 2052 patients aged ≥ 65 years who underwent hip fracture surgery were included in the study. Patient information was collected on admission, during hospitalization, by phone interview and at the geriatric outpatient clinic 4 to 6 months after the fracture. Of the 1331 eligible patients, Grip strength, Timed Up and Go -test (TUG), Elderly Mobility Scale (EMS), mobility change compared to pre-fracture mobility level, Basic Activities of Daily Living (BADL) and Instrumental Activities of Daily Living (IADL) were used to determine physical performance and functional ability. Logistic regression was used for the analyses which was adjusted for gender, age, American Society of Anesthesiologists score, diagnosis of cognitive disorder, pre-fracture living arrangements, mobility and need of mobility aid.

RESULTS

Patients with pertrochanteric hip fracture had an EMS lower than 14 (Odds Ratio (OR) 1.38, 95% confidence intervals (CI) 1.00-1.90), TUG time ≥ 20 s (OR 1.69, 95% CI 1.22-2.33) and they had declined in mobility (OR 1.58, 95% CI 1.20-2.09) compared to femoral neck fracture patients 4 to 6 months post-hip fracture in multivariable-adjusted logistic regression analyses. Grip strength and functional ability (IADL, BADL) 4 to 6 months after hip fracture did not differ between fracture types. There were no statistically significant differences in physical performance in patients with a subtrochanteric fracture compared to patients with a femoral neck fracture.

CONCLUSIONS

Pertrochanteric hip fracture independently associated with poorer physical performance 4 to 6 months post hip fracture compared to other hip fracture types. Pertrochanteric hip fracture patients should be given special attention in terms of regaining their previous level of mobility.

Is bisphosphonate use a risk factor for atypical periprosthetic/peri-implant fractures? - A metanalysis of retrospective cohort studies and systematic review of the current evidence

INTRODUCTION

Atypical periprosthetic/peri-implant fractures are not recognised in any widely used classification and therefore little focus is given to them. Multiple case reports and case series demonstrate these fractures exist and are related to bisphosphonate (BP) use.

HYPOTHESIS

Are patients taking long-term BPs at an increased risk of developing an atypical periprosthetic/peri-implant fracture? Is a particular BP drug causing an increased risk of fracture? Is there a correlation between the time of BP use and the incidence of fractures? Do vitamin D analogues or parathyroid hormones reduce the time to union?

MATERIAL AND METHODS

Systematic review of all available evidence on the existence of periprosthetic/peri-implant atypical fractures in patients taking long-term BPs and metanalysis of available retrospective cohort studies. Selected 1 systematic review, 7 retrospective cohort studies (5 used for metanalysis) and 32 case reports.

RESULTS

Metanalysis reported a risk ratio of 14.1, p=0.25, suggesting bisphosphonates are a risk factor in the development of periprosthetic/peri-implant atypical fractures. The secondary outcomes couldn't be reliably identified due to the small size of available studies and risk of significant bias.

DISCUSSION

Atypical periprosthetic/peri-implant fractures are an entity and seem to be associated with the use of bisphosphonates. The benefits of bisphosphonates use outweigh the risks, but clinicians should be aware of atypical fractures and actively search for them when patients on long-term bisphosphonates attend with non-specific pain close to the implant/prosthesis or reduced mobility.

LEVEL OF EVIDENCE

II, Systematic review and metanalysis.

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).

A brief review and clinical evidences of teriparatide therapy for atypical femoral fractures associated with long-term bisphosphonate treatment

The risk of bisphosphonate (BP)-associated atypical femur fracture (AFF) has markedly increased over recent decades due to suppression of bone turnover, accumulation of structural micro-damage and reduction of bone remodeling consequent to long-term BP treatment. These medications further delay bone union and result in challenging clinical management. Teriparatide (TPTD), a synthetic human parathyroid hormone, exhibits unique anabolic effects and can increase bone remodeling and improve bone microarchitecture, further promoting fracture healing and reducing the rate of bone non-union. In this study, we briefly define AFF as well as the effects of BPs on AFFs, detailed the role of TPTD in AFF management and the latest clinical therapeutic findings. We have confirmed that TPTD positively promotes the healing of AFFs by reducing the time to bone union and likelihood of non-union. Thus, teriparatide therapy could be considered as an alternative treatment for AFFs, however, further research is required for the establishment of effective clinical guidelines of TPTD use in the management of AFF.

Fracture definitions in observational osteoporosis drug effects studies that leverage healthcare administrative (claims) data: a scoping review

Healthcare administrative (claims) data are commonly utilized to estimate drug effects. We identified considerable heterogeneity in fracture outcome definitions in a scoping review of 57 studies that estimated osteoporosis drug effects on fracture risk. Better understanding of the impact of different fracture definitions on study results is needed.

PURPOSE

Healthcare administrative (claims) data are frequently used to estimate the real-world effects of drugs. Fracture incidence is a common outcome of osteoporosis drug studies. We aimed to describe how fractures are defined in studies that use claims data.

METHODS

We searched MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCO), and gray literature for studies published in English between 2000 and 2020 that estimated fracture effectiveness (hip, humerus, radius/ulna, vertebra) or safety (atypical fracture of the femur, AFF) of osteoporosis drugs using claims data in Canada and the USA. Literature searches, screening and data abstraction were completed independently by two reviewers.

RESULTS

We identified 57 eligible studies (52 effectiveness, 3 safety, 2 both). Hip fracture was the most common fracture site studied (93%), followed by humerus (66%), radius/ulna (59%), vertebra (61%), and AFF (9%). Half (n = 29) of the studies did not indicate specific data sources, codes, or cite a validation paper. Of the papers with sufficient detail, heterogeneity in fracture definitions was common. The most common definition within each fracture site was used by less than half of the studies that examined effectiveness (12 definitions in 29 hip fracture papers, 8 definitions in 17 humerus papers, 8 definitions in 13 radius/ulna papers, 9 definitions in 15 vertebra papers), and 3 definitions among 4 AFF papers.

CONCLUSION

There is ambiguity and heterogeneity in fracture outcome definitions in studies that leverage claims data. Better transparency in outcome reporting is needed. Future exploration of how fracture definitions impact study results is warranted.

Atypical femur fractures associated with bisphosphonate therapy: post-operative outcomes

PURPOSE

Bisphosphonates are commonly used medication for the treatment of osteoporosis, and a well-established complication of this medication is bisphosphonate-associated atypical femur fractures (BAAFFs). The aim of this study was to assess the post-operative functional and radiographic outcomes of surgically treated BAAFFs.

METHODS

An analysis of patients treated at a university-affiliated institution was performed. Patients who had undergone surgical fixation for a subtrochanteric or shaft of femur fracture which had been classified as atypical and treated with bisphosphonate therapy at the time of fracture were included. The outcome measures assessed included post-operative complications, length of stay, discharge destination, post-operative function, independence in activities of daily living (ADLs) and fracture union.

RESULTS

Twenty patients were included in this study with a mean age of 75.2 years. The cohort was predominantly female. The average duration of bisphosphonate therapy was 7.35 years. Nine patients had contralateral bisphosphonate-related stress reactions at the time of their initial fracture and underwent prophylactic surgical intervention. The majority of patients received cephalomedullary nail fixation (95%) with more than half (65.0%) of the cohort experiencing one or more post-operative complications. The median length of stay was 6.5 days and 50% of the cohort required inpatient rehabilitation. At final review, independent mobilisation was recorded in only 10.0% of patients, and 70% of patients were dependent with their ADLs at their latest follow-up. Average follow-up was 8 months, and only six cases demonstrated union at the six-month review, with delayed union between 9 and 12 months being common.

CONCLUSION

Patients with BAAFFs experience high rates of complications, record poor post-operative functional outcomes, and demonstrate a delayed time to union. Nearly half of our cohort had radiographic evidence of bilateral pathology.

Development of Atypical Ulnar Fracture is Associated with Bisphosphonate Therapy and Severe Spinal Deformity: A Case Report

Atypical ulna fracture (AUF) is relatively rare and is known to be associated with prolonged bisphosphonate (BP) use. The developmental mechanism remains unclear. We report a patient with an AUF associated with BP and severe spinal deformity. The patient was an 85-year-old woman receiving oral alendronate for 8 years without vitamin D supplementation. During regular kitchen work, she needed left upper limb support. She presented with atraumatic pain over the ulna. Radiographs revealed a transverse fracture in the proximal ulna and ulna bowing deformity. Whole-spine standing radiographs showed severe degenerative kyphoscoliosis. The skin induration with pigmentation on her left elbow that suggested prolonged overload and during standing work, coincided exactly with fracture location. This report suggests that ‘direct stress’, with persistent local overload on the proximal ulna, is one of the developmental mechanisms of AUF, in addition to persistent suppression of bone remodelling by prolonged BP use and vitamin D deficiency.

Level of Evidence: Level V (Therapeutic)

Risk of subtrochanteric and femoral shaft fractures due to bisphosphonate therapy in asthma: a population-based nested case-control study

Concerns have been raised over the association between bisphosphonates and atypical fractures in subtrochanteric and femoral shaft regions, but the potential risk of these fractures due to bisphosphonate use in asthma has not been examined.

INTRODUCTION

Bisphosphonates are used as first-line treatment for osteoporosis; however, concerns have been raised over their association with atypical subtrochanteric (ST) and femoral shaft (FS) fractures. The potential risk of atypical ST/FS fractures from bisphosphonate use in asthma has not been examined.

METHODS

A nested case-control study was conducted using linked data from the Clinical Practice Research Datalink (CPRD) and Hospital Episode Statistics (HES) databases. Using an asthma cohort, we identified patients with atypical ST/FS fractures and sex, age, and practice-matched controls. Conditional logistic regression was used to determine the association between bisphosphonate exposure and atypical ST/FS fractures.

RESULTS

From a cohort of 69,074 people with asthma, 67 patients with atypical ST/FS fractures and 260 matched control subjects were identified. Of the case patients, 40.3% had received bisphosphonates as compared with 14.2% of the controls corresponding to an adjusted odds ratio (aOR) of 4.42 (95%CI, 2.98 to 8.53). The duration of use influenced the risk with long-term users to be at a greater risk (> 5 years vs no exposure; aOR = 7.67; 95%CI, 1.75 to 33.91). Drug withdrawal was associated with diminished odds of atypical ST/FS fractures.

CONCLUSION

Regular review of bisphosphonates should occur in patients with asthma. The risks and benefits of bisphosphonate therapy should be carefully considered in consultation with the patient. To improve AFF prevention, early signs which may warrant imaging, such as prodromal thigh pain, should be discussed.

Incomplete Atypical Femoral Fracture Treated by Prophylactic Intramedullary Nail Fixation: A Case Series

Long-term bisphosphonate use may be associated with atypical femoral fractures. In this report, we describe three cases of bisphosphonate-associated incomplete atypical femoral fracture, treated by prophylactic intramedullary nail fixation. Patients with long-term intake of bisphosphonates must be carefully monitored; atypical femoral fracture should be suspected in the presence of symptoms such as thigh pain. Its early identification is important to avoid a complete fracture and invasive surgery, and prophylactic fixation is recommended for incomplete atypical femoral fractures.

Characterization, pharmacokinetics, and pharmacodynamics of anti-Siglec-15 antibody and its potency for treating osteoporosis and as follow-up treatment after parathyroid hormone use

Recent studies have established the idea that Siglec-15 is involved in osteoclast differentiation and/or function, and it is anticipated that therapies suppressing Siglec-15 function can be used to treat bone diseases such as osteoporosis. We have produced rat monoclonal anti-Siglec-15 antibody (32A1) and successively generated humanized monoclonal anti-Siglec-15 antibody (DS-1501a) from 32A1. Studies on the biological properties of DS-1501a showed its specific binding affinity to Siglec-15 and strong activity to inhibit osteoclastogenesis. 32A1 inhibited multinucleation of osteoclasts and bone resorption (pit formation) in cultured mouse bone marrow cells. 32A1 also inhibited pit formation in cultured human osteoclast precursor cells. Maximum serum concentration and serum exposure of DS-1501a in rats were increased in a dose-dependent manner after single subcutaneous or intravenous administration. Furthermore, single administration of DS-1501a significantly suppressed bone resorption markers with minimal effects on bone formation markers and suppressed the decrease in bone mineral density (BMD) of the lumbar vertebrae in ovariectomized (OVX) rats. In histological analysis, the osteoclasts distant from the chondro-osseous junction of the tibia tended to be flattened, shrunken, and functionally impaired in 32A1-treated rats, while alkaline phosphatase-positive osteoblasts were observed throughout the metaphyseal trabeculae. In addition, we compared the efficacy of 32A1 with that of alendronate (ALN) as follow-up medicine after treatment with parathyroid hormone (PTH) using mature established osteoporosis rats. The beneficial effect of PTH on bone turnover disappeared 8 weeks after discontinuing the treatment. The administration of 32A1 once every 4 weeks for 8 weeks suppressed bone resorption and bone formation when the treatment was switched from PTH to 32A1, leading to the maintenance of BMD and bone strength. Unlike with ALN, the onset of suppression of bone resorption with 32A1 was rapid, while the suppression of bone formation was mild. The improvement of bone mass, beneficial bone turnover balance, and suppression of osteoclast differentiation/multinucleation achieved by 32A1 were supported by histomorphometry. Notably, the effects of 32A1 on bone strength, not only structural (extrinsic) but also material (intrinsic) properties, were significantly greater than those of ALN. Since the effect of 32A1 on BMD was moderate, its effect on bone strength could not be fully explained by the increase in BMD. The beneficial balance of bone turnover caused by 32A1 might, at least in part, be responsible for the improvement in bone quality. This is the first report describing the effects of anti-Siglec-15 antibody in OVX rats; the findings suggest that this antibody could be an excellent candidate for treating osteoporosis, especially in continuation therapy after PTH treatment, due to its rapid action and unprecedented beneficial effects on bone quality.

Open Reduction and Internal Fixation of Simultaneous, Bilateral, Atypical Femoral Shaft Fractures After Nine Years of Bisphosphonate Treatment

Bisphosphonates are generally used to treat osteoporosis and decrease the risk of femoral neck and vertebral fractures in patients with osteoporosis. Recently, it has been suggested that long-term bisphosphonate use can lead to decreased bone remodeling and an increased risk of atypical fractures. Atypical fractures often occur in the femur. The purpose of the present report is to describe a rare case of simultaneous, bilateral, atypical femoral fractures. An 80-year-old female was walking when she sustained bilateral femoral fractures that were diagnosed as atypical. The patient had received bisphosphonate treatment over the prior nine years.

Osteoporosis therapies and their mechanisms of action (Review)

Osteoporosis is a common disease that affects millions of patients worldwide and is most common in menopausal women. The main characteristics of osteoporosis are low bone density and increased risk of fractures due to deterioration of the bone architecture. Osteoporosis is a chronic disease that is difficult to treat; thus, investigations into novel effective therapeutic methods are required. A number of studies have focused on determining the most effective treatment options for this disease. There are several treatment options for osteoporosis that differ depending on the characteristics of the disease, and these include both well-established and newly developed drugs. The present review focuses on the various drugs available for osteoporosis, the associated mechanisms of action and the methods of administration.

Revision osteosynthesis after primary treatment of atypical ulnar fractures associated with bisphosphonate usage - Nonunion after ordinary open reduction and internal fixation

BACKGROUND

We performed revision surgeries to treat nonunion of bisphosphonate-associated ulnar fractures that had originally been treated, after misdiagnosis, using the typical open reduction/internal fixation (ORIF).

METHODS

Of nine cases of ulnar nonunion initially treated at other institutions, we performed revision surgeries on four that met our inclusion/exclusion criteria. All previous implants were removed; the areas of nonunion were resected, and strut bone grafts were inserted and fixed with locking plates. Radiological assessments were performed monthly for 3 months after surgery and then every 3 months for 1 year.

RESULTS

All patients were female, with a mean age of 71.8 years. All patients had been taking bisphosphonate for a mean of 7.2 years. The primary fixation methods used at other institutions were intra-medullary nailing (n = 1) and placement of 3.5-mm locking plates (n = 3). In one patient (patient 1), the contralateral (right) ulna developed a new fracture at 1 month after revision surgery on the left ulna. Another patient (patient 3) exhibited an incomplete fracture in the contralateral (right) ulna. All four patients exhibited hip fractures (bilateral in three). All revisions resulted in final union at a mean of 4.8 months postoperatively.

CONCLUSION

Atypical ulnar fractures should be suspected in elderly women on long-term bisphosphonate treatment. Union will fail with standard ORIF for atypical ulnar fractures, because the fracture occurred due to compromised normal bone metabolism as reflected in the bone resorption, remodeling, and healing processes. Revision osteosynthesis using a locking plate with callus resection and strut/cancellous bone graft provided satisfactory results.

LEVEL OF EVIDENCE

Therapeutic level IV.

Anti-Siglec-15 antibody suppresses bone resorption by inhibiting osteoclast multinucleation without attenuating bone formation

Anti-resorptive drugs are widely used for the treatment of osteoporosis, but excessive inhibition of osteoclastogenesis can suppress bone turnover and cause the deterioration of bone quality. Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) is a transmembrane protein expressed on osteoclast precursor cells and mature osteoclasts. Siglec-15 regulates proteins containing immunoreceptor tyrosine-based activation motif (ITAM) domains, which then induce nuclear factor of activated T-cells 1 (NFATc1), a master transcription factor of osteoclast differentiation. Anti-Siglec-15 antibody modulates ITAM signaling in osteoclast precursors and inhibits the maturation of osteoclasts in vitro. However, in situ pharmacological effects, particularly during postmenopausal osteoporosis, remain unclear. Here, we demonstrated that anti-Siglec-15 antibody treatment protected against ovariectomy-induced bone loss by specifically inhibiting the generation of multinucleated osteoclasts in vivo. Moreover, treatment with anti-Siglec-15 antibody maintained bone formation to a greater extent than with risedronate, the first-line treatment for osteoporosis. Intravital imaging revealed that anti-Siglec-15 antibody treatment did not cause a reduction in osteoclast motility, whereas osteoclast motility declined following risedronate treatment. We evaluated osteoclast activity using a pH-sensing probe and found that the bone resorptive ability of osteoclasts was lower following anti-Siglec-15 antibody treatment compared to after risedronate treatment. Our findings suggest that anti-Siglec-15 treatment may have potential as an anti-resorptive therapy for osteoporosis, which substantially inhibits the activity of osteoclasts while maintaining physiological bone coupling.

Dynamic Effects of the Third Generation Bisphosphonate of Risedronate on Rat Osteoporotic Fractures for Clinical Usage Guidance

OBJECTIVE

To better understand the risks of bisphosphonates in order to develop guidance for appropriate clinical usage, to compared femoral fracture healing at different time points and to explore the effects of Residronate on fracture healing.

METHODS

Osteoporosis model was achieved by ovariectomy surgery, followed by surgical incision of left femoral shaft 4 weeks after ovariectomy surgery. Three days after fracture surgery, risedronateor saline was fed by intragastric administration. X ray examination was used to check the callus formation, Bone Mineral Density (BMD), Bone Mineral Content (BMC), biomechanical, imaging and micromorphological of bone tissue as well as the trabecular bone parameters were all examined. The femoral pathology tissue of each rat was used to analyze trabecular bone parameters, including trabecular bone volume/tissue volume (Tb. BV/TV), bone surface to tissue volume ratio (BS/TV), trabecular bone mineral density (Tb. BMD), trabecular bone number (Tb. N), trabecular bone thickness (Tb. Th) and small bone Trabecular bone space (Tb. Sp).

RESULTS

Via X-ray and pathologically, risedronate treatment promoted the callus forming at the fracture site during the following 6 weeks after osteoporotic fracture by X-ray (P < 0.01), increased the local bone mineral density (P < 0.01), and accelerated the fracture healing during the first 3 weeks (P <0.01), but delayed facture healing in the later 3 weeks (P < 0.01). Risedronate increased the bone continuity of fracture at 7th week, but this phenomenon was not found at the 10th week (P < 0.01). Delayed fracture healing occurred locally at the fracture site. At 7th week, Risedronate may promote cartilage cells proliferating at fracture site, increase the dense of bone trabeculae and the connection of bone trabeculae, thicken the bone cortex showing better fracture healing than OPF-Saline groups (P < 0.01). However, these parameter did not continue during the 7th and 10th weeks. Comparing the first and the later 3 weeks, the rats in group Osteoporotic Fracture-Risedronate (OPF-RD) accelerated the local fracture healing in the first 3 weeks but not in the last 3 weeks, which is consistent for the BMD and BMC among each group (P < 0.05). Through evaluation of bone mineral density and bone mineral content, risedronate dramatically increased the BMD at the fracture site and resulted in reduction of BMC by risedronate at the fracture site (P < 0.05) among each group still exist, indicating dramatic (P < 0.05). Through load testing, Risedronate increased the structural strength and mechanical indexes of the new callus (P < 0.01).

CONCLUSION

Risedronate can improve the structural strength and mechanical index of newborn callus. Longer than 7 weeks usage of third generation bisphosphonate of risedronate does not contribute to osteoporotic fracture.

Fracture outcome definitions in observational osteoporosis drug effects studies: a scoping review protocol

OBJECTIVE

The objective of this review is to describe fracture outcome definitions in observational osteoporosis drug effects studies from Canada and the United States of America.

INTRODUCTION

Health care administrative data are commonly utilized in pharmacoepidemiologic studies. These data are used to define outcomes, such as fractures, and are critical to determining real-world safety and effectiveness of medications. However, there is no current standard for fracture outcome definitions in observational studies. As a result, fractures are inconsistently defined. To inform future research, a synthesis of how fractures are defined in observational studies using health care administrative claims data is needed. Providing clarity on how fractures are defined will provide guidance for future research.

INCLUSION CRITERIA

We will include observational studies from the United States and Canada published in English from 2000 to the present that consider the impact of osteoporosis pharmacotherapies on fracture risk and leverage health care administrative data.

METHODS

This review will follow the three-step JBI methodology for scoping reviews. We will search MEDLINE (Ovid), Embase (Ovid), and CINAHL (EBSCO). Following de-duplication, titles and abstracts will be screened independently by two reviewers. We will then conduct full-text screening for eligible studies. In addition, Canadian and American government pharmacovigilance websites will be searched to identify gray literature. Data extraction will be completed by two reviewers. Results will be presented in figures and tabular form.

Inflammatory conversion of quiescent osteoblasts by metastatic breast cancer cells through pERK1/2 aggravates cancer-induced bone destruction

Disruption of bone homeostasis caused by metastatic osteolytic breast cancer cells increases inflammatory osteolysis and decreases bone formation, thereby predisposing patients to pathological fracture and cancer growth. Alteration of osteoblast function induces skeletal diseases due to the disruption of bone homeostasis. We observed increased activation of pERK1/2 in osteolytic breast cancer cells and osteoblasts in human pathological specimens with aggressive osteolytic breast cancer metastases. We confirmed that osteolytic breast cancers with high expression of pERK1/2 disrupt bone homeostasis via osteoblastic ERK1/2 activation at the bone-breast cancer interface. The process of inflammatory osteolysis modulates ERK1/2 activation in osteoblasts and breast cancer cells through dominant-negative MEK1 expression and constitutively active MEK1 expression to promote cancer growth within bone. Trametinib, an FDA-approved MEK inhibitor, not only reduced breast cancer-induced bone destruction but also dramatically reduced cancer growth in bone by inhibiting the inflammatory skeletal microenvironment. Taken together, these findings suggest that ERK1/2 activation in both breast cancer cells and osteoblasts is required for osteolytic breast cancer-induced inflammatory osteolysis and that ERK1/2 pathway inhibitors may represent a promising adjuvant therapy for patients with aggressive osteolytic breast cancers by altering the shared cancer and bone microenvironment.

Bone Nanomechanical Properties and Relationship to Bone Turnover and Architecture in Patients With Atypical Femur Fractures: A Prospective Nested Case-Control Study

Atypical femur fractures (AFFs) are well‐established serious complication of long‐term bisphosphonate and denosumab therapy in patients with osteopenia or osteoporosis. To elucidate underlying mechanism(s) for the development of AFF, we performed a nested case‐control study to investigate bone tissue nanomechanical properties and prevailing bone microstructure and tissue‐level remodeling status as assessed by bone histomorphometry. We hypothesized that there would be differences in nanomechanical properties between patients with and without AFF and that bone microstructure and remodeling would be related to nanomechanical properties. Thirty‐two full‐thickness transiliac bone biopsies were obtained from age‐ and sex‐matched patients on long‐term bisphosphonate therapy with (n = 16) and without an AFF (n = 16). Standard histomorphometric measurements were made in each sample on three different bone envelopes (cancellous, intracortical, and endosteal). Iliac bone wall thickness was significantly lower on all three bone surfaces in patients with AFF than in those without AFF. Surface‐based bone formation rate was suppressed similarly in both groups in comparison to healthy premenopausal and postmenopausal women, with no significant difference between the two groups. Nanoindentation was used to assess material properties of cortical and cancellous bone separately. Elastic modulus was higher in cortical than in cancellous bone in patients with AFF as well as compared to the elastic modulus of cortical bone from non‐AFF patients. However, the elastic modulus of the cancellous bone was not different between AFF and non‐AFF groups or between cortical and cancellous bone of non‐AFF patients. Resistance to plastic deformation was decreased in cortical bone in both AFF and non‐AFF groups compared to cancellous bone, but to a greater extent in AFF patients. We conclude that long‐term bisphosphonate therapy is associated with prolonged suppression of bone turnover resulting in altered cortical remodeling and tissue nanomechanical properties leading to AFF. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Discontinuation of bisphosphonates in seniors: a systematic review on health outcomes

PURPOSE

Bisphosphonates are used to treat osteoporosis. Despite their benefits on bone mineral density (BMD) and fractures, they have shown adverse effects, sometimes severe, during chronic use. Taken for several years, they achieve long-term bone retention, making deprescribing feasible. This review aimed to synthesize evidence on the success and health outcomes of deprescribing of bisphosphonates in seniors, aged over 60 years.

METHODS

The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, including articles in English, French, or German published before July 2020. Eligible studies included seniors having discontinued bisphosphonates and reported on health outcomes; some allowed meta-analyses on fracture risk.

RESULTS

The review included 9 RCTs and 9 cohort studies of moderate quality. Bisphosphonates were discontinued after 2 to 7 years of use, and BMD or fractures were assessed during follow-up of 0.5 to 5 years. A significant reduction in BMD after discontinuation was observed in 9 of 10 studies. Results on fracture risk after discontinuation are mitigated: 6 RCT extensions showed no increase in the risk of any osteoporotic fractures after discontinuation. Meta-analyses including 4 RCTs showed an increased odds ratio of vertebral fractures of 2.04 (95% CI, 1.39-2.99) among discontinuers. Results from 2 large cohort studies showed no increased risks of any osteoporotic or vertebral fractures, while 2 studies found increased fracture risks.

CONCLUSION

Bisphosphonates have successfully been discontinued low overall fracture risk after at least 3 years of use, but a risk for decreased BMD and increased vertebral fractures remained.

The Effect of Teriparatide on the Hip: A Literature Review

Teriparatide (TPTD) is a bone-forming agent used to treat postmenopausal osteoporosis. Since hip fractures are related to higher morbidity and mortality rates than other fractures, efficacious osteoporosis drugs for the hip are critical. We reviewed research articles reporting the efficacy of TPTD in terms of bone mineral density (BMD), fractures prevention, changes in the outer diameter, cortical thickness and porosity, post-operative periprosthetic BMD loss, and healing of typical and atypical fractures of the hip. Data meta-analyses indicated that TPTD not only increased the BMD of the proximal femur but also decreased the risk of hip fractures. Even though TPTD increases the cortical bone porosity of the proximal femur, the bone strength does not decrease as the majority of the porosity is located at the endocortex; further, it increases the outer diameter and thickens the cortical bone. TPTD stimulates bone remodeling and facilitates callus maturity and fracture healing. There have been many reports on improving the effect of TPTD on the healing of atypical fractures; therefore it is advisable to use TPTD considering the increase benefit compared to the risk.

Is vitamin K2 a treatment choice for atypical femoral fractures in patients with secondary osteoporosis?

An atypical femoral fracture (AFF) is a rare complication associated with excessive inhibition of osteoclast expression during treatment of osteoporosis. We herein describe a patient who had been treated with alendronate for more than 10 years and subsequently developed an AFF that healed after treatment with vitamin K₂ (VK2). We also discuss the potential beneficial effects of VK2 on the healing of AFFs. A 48-year-old Asian man with secondary osteoporosis was treated with alendronate for more than 10 years. The patient underwent surgical treatment for a complete AFF of the right femur. Six months postoperatively, he complained of pain in his left thigh. X-ray examination revealed an incomplete AFF of the left femoral shaft. He was then treated with VK2. After 4 months of VK2 treatment, the patient reported that the pain in his left thigh had decreased, and follow-up X-ray examination demonstrated healing of the left AFF line. This case report indicates that VK2 may be a potential direction for pharmacological treatment of AFFs in future research.

Duration of Bisphosphonate Drug Holidays in Osteoporosis Patients: A Narrative Review of the Evidence and Considerations for Decision-Making

Bisphosphonates are first-line therapy for osteoporosis, with alendronate, risedronate, and zoledronate as the main treatments used globally. After one year of therapy, bisphosphonates are retained in bone for extended periods with extended anti-fracture effects after discontinuation. Due to this continued fracture protection and the potential for rare adverse events associated with long-term use (atypical femoral fractures and osteonecrosis of the jaw), a drug holiday of two to three years is recommended for most patients after long-term bisphosphonate therapy. The recommendation for a drug holiday up to three years is derived primarily from extensions of pivotal trials with alendronate and zoledronate and select surrogate marker studies. However, certain factors may modify the duration of bisphosphonate effects on a drug holiday and warrant consideration when determining an appropriate time off-therapy. In this narrative review, we recall what is currently known about drug holidays and discuss what we believe to be the primary considerations and areas for future research regarding drug holiday duration: total bisphosphonate exposure, type of bisphosphonate used, bone mineral density and falls risk, and patient sex and body weight.

Comparison of clinical outcomes with hip replacement versus PFNA in the treatment of intertrochanteric fractures in the elderly: A systematic review and meta-analysis (PRISMA)

BACKGROUND

The purpose of this meta-analysis was to evaluate the clinical efficacy and safety of HR and PFNA in the treatment of intertrochanteric fractures in the elderly.

METHODS

We carried out this review according to the principle of preferred reporting items for systematic reviews and meta-analyses (PRISMA) guideline. The clinical randomized controlled trials (RCTs), prospective cohort studies, retrospective cohort studies (RCSs), and case-control studies involving HR and PFNA in the treatment of intertrochanteric fractures in the elderly from 2000 to 2020 were compared by searching Web of Science, Pubmed, the Cochrane Library, and Embase. The quality of the included cohort study (CS) lines was evaluated using the Newcastle-Ottawa Scale (NOS). The quality of the included RCT lines was evaluated using Jadad. Forest plots were drawn by RevMan5.4 software based on the results and the data were analyzed.

RESULTS

After screening, a total of 9 articles were included, of which one was a clinical RCT and eight were RCSs with 1374 patients. The operative time of the PFNA group was shorter [WMD = 15.20; 95% CI (13.17, 17.23), P < .05] and the intraoperative blood loss was less [WMD = 178.81; 95% CI (97.24, 260.38), P < .05] than the HR group, while the first weight-bearing time of the HR group was shorter [WMD = -7.70; 95% CI (-10.54, -4.86), P  < .05] than the PFNA group. There was no significant difference in the length of hospital stay, HHS, postoperative orthopedic complications, and postoperative medical complications between the 2 groups.

CONCLUSION

With the development of HR technology and minimally invasive technology, the trauma caused by surgery is decreasing. Under the premise of improving perioperative management, such as optimizing the preoperative preparation and postoperative management, shortening the operative time, reducing intraoperative blood loss, and actively managing co-existing diseases, HR has more advantages than PFNA in the treatment of senile intertrochanteric fractures.

A comparison of alendronate to varying magnitude PEMF in mitigating bone loss and altering bone remodeling in skeletally mature osteoporotic rats

Pulsed electromagnetic field (PEMF) treatments stimulate bone formation activities though further work is needed to optimize its therapeutic benefit. PEMF can generate local potential gradients and electric currents that have been suggested to mimic bone electrochemical responses to load. In line with this reasoning, a recent publication reported that PEMF application on isolated bone tissue induced detectable micro-vibrations (doi:https://doi.org/10.1109/TMAG.2016.2515069). To determine the ability of PEMF to intervene in a rat model of osteoporosis, we tested its effect on trabecular and cortical bone following ovariectomy. Four PEMF treatments, with increasing sinusoidal amplitude rise with time (3850 Hz pulse frequency and 15 Hz repetition rate at 10 tesla/sec (T/s), 30 T/s, 100 T/s, or 300 T/s), were compared to the efficacy of an osteoporosis drug, alendronate, in reducing levels of trabecular bone loss in the proximal tibia. Herein, the novel findings from our study are: (1) 30 T/s PEMF treatment approached the efficacy of alendronate in reducing trabecular bone loss, but differed from it by not reducing bone formation rates; and (2) 30 T/s and 100 T/s PEMF treatments imparted measurable alterations in lacunocanalicular features in cortical bone, consistent with osteocyte sensitivity to PEMF in vivo. The efficacy of specific PEMF doses may relate to their ability to modulate osteocyte function such that the 30 T/s, and to a lesser extent 100 T/s, doses preferentially antagonize trabecular bone resorption while stimulating bone formation. Thus, PEMF treatments of specific magnetic field magnitudes exert a range of measurable biological effects in trabecular and cortical bone tissue in osteoporotic rats.

Morphological and Morphometrical Analyses of Fracture-Healing Sites of an Atypical Femoral Fracture in Patients with and without Long-Term Bisphosphonate Treatment for Osteoporosis: A Report of Two Cases

Bisphosphonates have been the first drug of choice for osteoporosis in the recent years because of their known ability to suppress osteoclast activity. The adverse effect of long-term bisphosphonate administration in the fracture-healing process is controversial. The aim of our study was to observe not only morphology but also morphometry of the fracture site of atypical femoral fracture with and without long-term bisphosphonate administration, in a case study of two difficult-to-obtain human samples. The patients with insufficient healing of atypical femoral fracture were treated with valgus wedge osteotomy. Histomorphometrical analysis was performed in bone samples of fracture sites harvested during osteotomy. The thickness of the femoral cortex was measured in the fracture site and the adjacent, non-fracture site. A comparative analysis of the content of hypertrophic osteoclasts in fracture sites, shape and size of osteons, mass, and ratio of the woven bone to the total bone mass was performed, comparing bisphosphonate-treated and untreated samples. In bisphosphonate-treated samples, we observed femoral cortex thickening at the fracture site; the appearance of hypertrophic osteoclasts; decreased bone resorption surface, decreased osteoclast numbers on the bone resorption surface, and increased ratio of multinuclear osteoclasts; osteons were misshapen and thin; and the mass and ratio of the woven bone to the total bone mass were higher. This study demonstrated that long-term bisphosphonate administration can alter the morphological features of the fracture site compared to its physiological state.

Trends in hip and distal femoral fracture rates in Italy from 2007 to 2017

Osteoporosis-related fractures are a growing public health concern worldwide due to high societal and economic burden. The study aims to assess trends in incidence rates of hip and distal femoral fractures and in the use of anti-osteoporosis drugs in Italy between 2007 and 2017. Patients with hip and distal femoral fractures (ICD-9-CM codes 820.x and 821.x) were identified in the Italian National Hospital Discharge Database while anti-osteoporosis medication data were retrieved from the National Observatory on the Use of Medicines Database. A joinpoint regression analysis was performed to identify the years where the trends in incidence rates of hip and distal femoral fractures changed significantly; the average annual percentage change for the period of observation was estimated. Hospitalizations for femoral fractures were 991,059, of which 91.4% were hip fractures and 76.5% occurred in women. Age-standardized hip fractures rate per 100,000 person-years decreased both in women (-8.7%; from 789.9 in 2007 to 721.5 in 2017) and in men (-4.3%; from 423.9 to 405.6), while the rate of distal femoral fractures increased by 23.9% in women (from 67.78 to 83.95) and 22.7% in men (from 27.76 to 34.06). These changes were associated with an increment in the use of anti-osteoporosis drugs from 2007 to 2011 (from 9.1 to 12.4 DDD/1000 inhabitants/day), followed by a plateau in the period 2012-2017. The use of bisphosphonates increased progressively from 2007 to 2010 (from 8.2 to 10.5 DDD/1000 inhabitants/day), followed by a plateau and then decreased from 2015 onwards. The decreasing trend of hip fractures could be related to a major intake of anti-osteoporosis medications while the increment of distal femoral fractures might be due to population aging and to the use of bisphosphonates and denosumab. Further research is needed to identify and implement interventions to prevent hip and distal femoral fractures.

Bacteroides vulgatus diminishes colonic microbiota dysbiosis ameliorating lumbar bone loss in ovariectomized mice

There is a need to discover additional kinds of intestinal microbiota to supplement the probiotic-treatment of postmenopausal osteoporosis. Increasing evidence has indicated that Bacteroides vulgatus has potential as a probiotic for ameliorating postmenopausal bone loss. In this study, ovariectomized female C57/BL6 mice were treated with B. vulgatus ATCC 8482 gavage to investigate the differences in colonic microbiota composition, inflammation signal pathways, inflammatory cytokines, bone turnover markers, and lumbar vertebrae microstructure compared with the control group. Our results show that B. vulgatus ATCC 8482 diminished microbiota dysbiosis and subsequently down-regulated the colonic lipopolysaccharide/TLR-4/p-NF-κB pathway leading to decreased serum TNF-α. This reduced TNF-α/RANKL expression and induced ALP and Runx-2 expression in the 5th lumbar vertebra, leading to amelioration of bone loss and microstructure destruction in the lumbar vertebra of ovariectomized mice. Taken together, these results indicate that B. vulgatus could be a probiotic for treatment of postmenopausal lumbar osteoporosis.

Therapeutic Dimensions of Bisphosphonates: A Clinical Update

Bisphosphonates (BPs) are a commonly used class of drugs for the treatment of bone disorders. An extensive review of BPs with their clinical efficacy and safety profile is unavailable. This study aimed to review the available literature on BPs, summarize their role in clinical therapy, and emphasize their safety profile. Authors reviewed the existing literature using the Google Scholar, PubMed, and Micromedex databases and analyzed the collected articles. BPs are the preferred medication for osteoporosis and other similar conditions owing to their efficient antiosteoclastic activity. Few of them are available in oral dosage forms; hence, they are patient-friendly. The mechanism of action, common adverse effects and their clinical applications, precautions and warnings pertaining to the route of administration, and safety profiles have been discussed in this manuscript. The common adverse effects are majorly related to the gastrointestinal, cardiovascular, and endocrine system. Upon chronic usage, patients may experience serious problems like osteonecrosis of the jaw and atypical bone fractures. Although BPs are effective and safe, they may cause GI adverse effects and rare cases of osteonecrosis. Patient counseling could prove beneficial in early identification and prevention of the adverse effects associated with BPs.

Fracture risk increased by concurrent use of central nervous system agents in older people: Nationwide case-crossover study

BACKGROUND

Multiple medication use among older patients is reported to increase fracture risk. But this association is unclear in different subgroups and has not been confirmed by a case-crossover study, which can eliminate measurable and unmeasurable time-invariant confounders.

OBJECTIVE

To estimate the fragility fracture risk associated with concurrent use of multiple central nervous system (CNS) agents in older patients using a case-crossover design.

METHODS

This study targeted almost all patients aged ≥65 years in Japan who incurred fragility fractures from May 2013 to September 2014, based on the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB Japan). Conditional logistic regression analysis estimated the risk of fragility fracture associated with the daily number of CNS agents, including subgroup analyses stratified by sex, age, and fracture location.

RESULTS

For 446,101 patients, the adjusted odds ratios (ORs) of fragility fracture increased almost linearly with number of CNS agents; 0, 0-1, 1-2, 2-3, 3-4, 4-5, and >5: OR reference, 1.21 (95% confidence interval, 1.18-1.23), 1.40 (1.35-1.46), 1.58 (1.49-1.67), 1.89 (1.74-2.05), 1.80 (1.60-2.03), and 1.90 (1.61-2.23; trend p < 0.001), respectively. A similar trend was observed for several subgroups, especially in males and those aged ≥85 years, showing marked linearity.

CONCLUSIONS

The increased risk of fragility fracture associated with the use of multiple CNS agents was robust in older people in Japan.

Atypical femur fractures: current understanding and approach to management

Osteoporosis and resulting osteoporotic fractures are responsible for significant morbidity, excess mortality, and health care costs in the developed world. Medical therapy for osteoporosis has been shown in multiple randomized controlled trials to reduce the risk of vertebral and non-vertebral fractures and hip fractures, and in some studies bisphosphonate medications have been associated with improved survival. Although the overall benefit to risk ratio of osteoporosis medications remains favorable, there have been concerns raised about the long-term safety of these treatments. Atypical femur fracture, which is a rare type of fracture that has been associated with the long-term use of potent antiresorptive bone medications, is a potentially devastating consequence of osteoporosis treatment. This paper reviews our current understanding of atypical femur fractures, their relationship to antiresorptive osteoporosis medications, and proposed strategies for management, in order to inform clinical decision making about the optimal use and duration of medical therapy for the treatment of patients with osteoporosis or at high risk for osteoporotic fractures.

Meta-analysis for the efficacy of bisphosphonates on hip fracture prevention

The aim of this study was to investigate the effect of bisphosphonates on preventing osteoporotic hip fracture in patients with or without prior major osteoporotic fracture. Randomized controlled trials (RCTs) and observational studies (OSs) based on electronic health records were used to assess bisphosphonate efficacy and were searched using PubMed, Scopus, and the Cochrane Library databases. Eight RCT studies and 14 OSs were extracted from the studies and quantitatively combined by random-effects meta-analysis. The odds ratio (OR) for all hip fractures in RCTs of 0.66, with a 95% confidence interval (CI) of 0.55-0.79, was lower than that in the OSs (OR 0.83; CI 0.74-0.94). The OR in patients with prior fracture was significantly reduced by bisphosphonates in both RCTs and OSs. Conversely, significant fracture reduction was not apparent in patients without prior fracture. A moderate relationship between prior major fracture rates and OR in hip fractures was defined. In patients with an average age of over 80 years, similar results were confirmed. In this meta-analysis, the efficacy of bisphosphonates was significant in patients with prior major fracture, recommending to prescribe for such patients. Their effect in patients without prior fracture, in contrast, remains unclear.

Bisphosphonate drug holidays: Risk of fractures and mortality in a prospective cohort study

PURPOSE

This study examined osteoporotic fractures and mortality in patients pretreated with bisphosphonates (BPs) during BP holidays and ongoing BP use.

METHODS

Interview-based prospective observational study in a cohort of 1973 patients with BP treatment for at least 80% of the total time of the preceding 4 years. Patients were recruited from 146 primarily endocrinological, orthopedic and rheumatological practices and clinics across Germany between May 2013 and June 2015. Outcomes were analyzed by Cox proportional hazards regression in relation to treatment status at the time of the first interview (model 1) or using time-dependent treatment variables (model 2). Temporal changes in fracture risk during BP holidays were evaluated by comparisons among 3 incremental levels of simple moving averages of BP treatment during the preceding 12 months (BP-SMA levels 0%, >0% to <50%, and ≥50%).

RESULTS

For an observation period of up to 25 months, the adjusted hazard ratios (HRs) in model 1 for BP holidays compared to ongoing BP use were 0.87 (95% confidence interval [CI] 0.59-1.28) for major osteoporotic fractures (MOFs), 0.95 (95% CI 0.70-1.28) for any clinical osteoporotic fracture, 0.96 (95% CI 0.55-1.68) for clinical vertebral fractures, and 0.86 (95% CI 0.50-1.48) for mortality. The risk of MOFs was higher for the BP-SMA level 0%, corresponding to a time >12 months since the start of a BP holiday, than for the BP-SMA level >0% to <50%, corresponding mainly to a time >6 to ≤12 months since the start of a BP holiday (adjusted HR 2.28, 95% CI 1.07-4.86). We found an interaction between prevalent vertebral fractures (PVFs) and BP-SMA-related time to first MOF for BP-SMA as a continuous variable (p for interaction 0.046 in the adjusted model). The adjusted HR for MOFs for the BP-SMA level 0% compared to the BP-SMA level >0% to <50% was 3.53 (95% CI 1.19-10.51) with a PVF but was 1.44 (95% CI 0.49-4.22) without a PVF.

CONCLUSIONS

Fracture risk and mortality in patients with preceding BP treatment did not significantly differ between BP holidays and ongoing BP use for an observation period up to 25 months when outcomes were analyzed in relation to treatment at the time of the first interview. However, in the presence of a PVF, the risk of MOFs was higher for a BP-SMA level corresponding to a time >12 months since the start of a BP holiday than for a BP-SMA level corresponding mainly to a time >6 to ≤12 months since the start of a BP holiday. The presence of a PVF may increase the relative risk of MOFs associated with a longer BP holiday.

Hip and Subtrochanteric or Femoral Shaft Fractures after Bisphosphonate Use in Korean Women, Using Korean National Sample Cohort

BACKGROUND

Concern about bisphosphonate-associated subtrochanteric and femoral shaft (ST/FS) fractures has been raised. However, its real risk is still debatable, because there is no study to estimate risk and benefit of bisphosphonate. The objective of this study was to evaluate the risk of typical hip fractures and ST/FS fractures among bisphosphonate users using nationwide database.

METHODS

We performed a retrospective cohort study using National Health Insurance Service-National Sample Cohort. We evaluated occurrence of the ST/FS and femoral neck and intertrochanteric (FN/IT) fractures among female bisphosphonate new users. Incidence rate of ST/FS and FN/IT fractures were compared between long-term users (≥ 1 year) and short-term users (< 1 year). Number needed to harm (NNH) for ST/FS and number needed to treat (NNT) for typical hip fracture were analyzed.

RESULTS

Among 46,420 bisphosphonate users, we identified 14,689 long-term users and 21,840 short-term users. During the study period, 61 long-term users and 36 short-term users had ST/FS fractures, while 204 long-term users and 511 short-term users had FN/IT fractures. The long-term user showed higher incidence rate of ST/FS fractures (67.1/100,000 person-years; 95% confidence interval [CI], 50.3-83.9) comparing with 31.2/100,000 person-years (95% CI, 21.0-41.4) in the short-term users. The incidence rate of FN/IT fractures was 225.5/100,000 person-years (95% CI, 194.6-256.5) in the long-term users and 448.6/100,000 person-years (95% CI, 409.7-487.5) in the short-term users. The NNH for ST/FS was 400, while the NNT for typical hip fracture was 105.

CONCLUSION

Our study suggested that physicians keep the significant benefit of bisphosphonate to prevent typical hip fracture in mind, even the concerns about bisphosphonate-associated ST/FS fractures.

Effects of the combined administration of risedronate and menatetrenone on bone loss induced by tacrolimus in rats

Tacrolimus, a calcineurin inhibitor, affects bone metabolism and increases the risk of fracture due to marked bone loss. Bisphosphonates increase the bone mineral density (BMD) in osteoporosis patients. Menatetrenone has less positive effects on BMD but reduces the risk of fracture by improving bone quality. In this study, we investigated the effectiveness of the combined administration of risedronate and menatetrenone against bone loss induced by tacrolimus. Wistar rats were divided into four groups: [1] control, [2] tacrolimus at 1.5 mg/kg, [3] tacrolimus + risedronate at 1.0 mg/kg, and [4] tacrolimus + risedronate + menatetrenone at 20 mg/kg. After the drugs were administered for 4 weeks, bone histomorphometric analysis was performed and bone strength was evaluated using a three point bending method. BMD was measured using quantitative computed tomography. Tacrolimus significantly reduced the BMD and strength properties of the lower limb bones. These tacrolimusinduced decreases were suppressed by risedronate treatment. The combined administration of risedronate and menatetrenone more significantly improved bone strength properties than risedronate alone. Bone histomorphometric analysis revealed a significant increase in bone resorption with tacrolimus. Risedronate alone significantly suppressed the tacrolimus-induced increase in bone resorption but simultaneously reduced bone formation. On the other hand, the combined administration of risedronate and menatetrenone suppressed the tacrolimus-induced increase in bone resorption, in addition to the significant risedronate-induced decrease in bone formation. This study suggests that the combined administration of risedronate and menatetrenone improves bone strength in tacrolimus-treated rats by preventing and ameliorating the risedronate-induced suppression of bone formation.

Horizontal fissuring at the osteochondral interface: a novel and unique pathological feature in patients with obesity-related osteoarthritis

Objectives

Obesity is a well-recognised risk factor for osteoarthritis (OA). Our aim is to characterise body mass index (BMI)-associated pathological changes in the osteochondral unit and determine if obesity is the major causal antecedent of early joint replacement in patients with OA.

Methods

We analysed the correlation between BMI and the age at which patients undergo total knee replacement (TKR) in 41 023 patients from the Australian Orthopaedic Association National Joint Replacement Registry. We then investigated the effect of BMI on pathological changes of the tibia plateau of knee joint in a representative subset of the registry.

Results

57.58% of patients in Australia who had TKR were obese. Patients with overweight, obese class I & II or obese class III received a TKR 1.89, 4.48 and 8.08 years earlier than patients with normal weight, respectively. Microscopic examination revealed that horizontal fissuring at the osteochondral interface was the major pathological feature of obesity-related OA. The frequency of horizontal fissure was strongly associated with increased BMI in the predominant compartment. An increase in one unit of BMI (1 kg/m²) increased the odds of horizontal fissures by 14.7%. 84.4% of the horizontal fissures were attributable to obesity. Reduced cartilage degradation and alteration of subchondral bone microstructure were also associated with increased BMI.

Conclusions

The key pathological feature in OA patients with obesity is horizontal fissuring at the osteochondral unit interface. Obesity is strongly associated with a younger age of first TKR, which may be a result of horizontal fissures.

Diabetes and fractures: new evidence of atypical femoral fractures?

Patients with diabetes have an increased risk of fractures. In this study, subtrochanteric and femoral shaft fractures were increased in patients with type 1 diabetes compared with the general population. In the light of this, more evidence points towards an association between diabetes and atypical femoral fractures.

INTRODUCTION

Patients with diabetes have an increased risk of femoral fractures, but little is known about the risk of atypical femoral fractures (AFFs). The aim of this study was to identify the risk of subtrochanteric and femoral shaft (ST/FS) fractures and estimate the risk of AFFs in patients with type 1 (T1D) and type 2 diabetes (T2D).

METHODS

From the nationwide Danish National Patient Register, we identified patients with T1D (n = 19,896), T2D (n = 312,188), and sex- and aged-matched controls without diabetes (n = 996,252) from the general population and all ST/FS fractures (n = 7509). Data were analyzed using a Cox proportional-hazards model and the incidence rate and rate ratio of ST/FS fractures were estimated.

RESULTS

The incidence rate of ST/FS fractures in T1D was 52.14 events per 100,000 person years and 73.21 per 100,000 person years in T2D. T1D was associated with an increased risk of ST/FS (HR 2.07 (95% CI 1.68-2.56)), whereas T2D was not (HR 0.99 (95% CI 0.94-1.10)). Previous ST/FS fractures were associated with an increased risk of subsequent ST/FS fractures (HR 6.95 (95% CI 6.00-8.05)) and the use of bisphosphonates with an increased risk of ST/FS fractures (HR 1.72 (95% CI 1.54-1.91)).

CONCLUSION

Patients with T1D have a higher risk of ST/FS fractures compared with sex- and age-matched controls. Since a proportion of ST/FS fractures are classified as AFFs, this could point towards the fact that AFFs also are increased in patients with T1D, but not T2D.

Different surgical outcomes in a patient with bilateral atypical femoral fracture related to bisphosphonate use with or without teriparatide treatment

Bisphosphonates (BPs) are first-line drugs for the treatment of osteoporotic fractures, but long-term use of BP reduces bone turnover and is associated with atypical femur fractures (AFFs). Additionally, BP treatment may cause delayed fracture healing or nonunion, which makes AFF treatment difficult. The incidence of AFF is generally low. In fact, there are only a few clinical reports of AFF and there is no controlled study on AFF treatment. Herein, we report a case of multiple osteoporotic fractures. After 5 years of BP treatment, left and right AFFs occurred within 2 years. The fracture types and surgical operations were the same, but the level of bone metabolism and drug treatment were different. The right AFF healed well following teriparatide initiation compared with non-healed left AFF with BP continuation; thus, our case can be considered a self-controlled study. Furthermore, we have reviewed the diagnosis and treatment of this case in detail and analyzed and investigated the potential causes of the different outcomes of AFFs between the two sides to inform the clinical treatment of atypical fractures. Mini Abstract We report a case of bilateral AFFs. The surgical treatments were the same, but the final treatment outcomes were different with or without teriparatide treatment. We investigated the potential causes of the different outcomes of AFFs between the two sides to inform the clinical treatment of AFFs.

Potential risks of rare serious adverse effects related to long-term use of bisphosphonates: An overview of systematic reviews

WHAT IS KNOWN AND OBJECTIVE

There have been concerns about a potential link between long-term use of bisphosphonates (BPs) for the treatment of osteoporosis and rare serious adverse effects, such as atypical femoral fractures. However, many reviews exist with conflicting conclusions about this issue. The aim of this overview of reviews was to systematically evaluate the risk of rare serious adverse effects of long-term use of BPs for the treatment of osteoporosis.

METHODS

We identified systematic reviews with meta-analyses of randomized controlled trials (RCTs) and (or) observational studies published in English or Chinese that evaluated the safety of BPs through to December 2018. The Cochrane library, PubMed, Web of Science and hand-searching of reference lists and clinical practice guidelines were electronically searched for data sources. Carcinogenicity, atypical fracture, osteonecrosis of jaw (ONJ) and fracture union time were specified as the primary outcomes. The methodological quality of each systematic review was assessed by two reviewers using the Assessment of Multiple Systematic Reviews (AMSTAR) tool, and the quality of evidence for key outcomes was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

RESULTS AND DISCUSSION

In total, 1376 potentially relevant citations were identified, of which only 8 systematic reviews with meta-analyses met the eligibility criteria. All the included reviews were published between 2012 and 2015 and documented the pooled estimates of effect size (relative risk [RR], odds ratio [OR] or hazard ratio [HR] and their 95% confidence intervals [95% CI]) for the incidence of adverse events. All included systematic reviews were of moderate or high quality. The median AMSTAR score was 7.5 (interquartile range, 5-10). However, evidence of the key outcomes was mainly of very low or moderate quality. BP treatment only increased the risk of atypical fracture and ONJ, and prolonged union time compared with placebo or other anti-osteoporosis drugs (P ＜ .05).

WHAT IS NEW AND CONCLUSION

This study indicated that long-term use of BPs could increase the risk of rare serious adverse effects, but the relationship between long-term use of BPs and carcinogenicity was often uncertain. Therefore, high-quality research and more complete inclusion criteria are needed.

Long-Term Drug Therapy and Drug Discontinuations and Holidays for Osteoporosis Fracture Prevention: A Systematic Review

BACKGROUND

Optimal long-term osteoporosis drug treatment (ODT) is uncertain.

PURPOSE

To summarize the effects of long-term ODT and ODT discontinuation and holidays.

DATA SOURCES

Electronic bibliographic databases (January 1995 to October 2018) and systematic review bibliographies.

STUDY SELECTION

48 studies that enrolled men or postmenopausal women aged 50 years or older who were being investigated or treated for fracture prevention, compared long-term ODT (>3 years) versus control or ODT continuation versus discontinuation, reported incident fractures (for trials) or harms (for trials and observational studies), and had low or medium risk of bias (ROB).

DATA EXTRACTION

Two reviewers independently rated ROB and strength of evidence (SOE). One extracted data; another verified accuracy.

DATA SYNTHESIS

Thirty-five trials (9 unique studies) and 13 observational studies (11 unique studies) had low or medium ROB. In women with osteoporosis, 4 years of alendronate reduced clinical fractures (hazard ratio [HR], 0.64 [95% CI, 0.50 to 0.82]) and radiographic vertebral fractures (both moderate SOE), whereas 4 years of raloxifene reduced vertebral but not nonvertebral fractures. In women with osteopenia or osteoporosis, 6 years of zoledronic acid reduced clinical fractures (HR, 0.73 [CI, 0.60 to 0.90]), including nonvertebral fractures (high SOE) and clinical vertebral fractures (moderate SOE). Long-term bisphosphonates increased risk for 2 rare harms: atypical femoral fractures (low SOE) and osteonecrosis of the jaw (mostly low SOE). In women with unspecified osteoporosis status, 5 to 7 years of hormone therapy reduced clinical fractures (high SOE), including hip fractures (moderate SOE), but increased serious harms. After 3 to 5 years of treatment, bisphosphonate continuation versus discontinuation reduced radiographic vertebral fractures (zoledronic acid; low SOE) and clinical vertebral fractures (alendronate; moderate SOE) but not nonvertebral fractures (low SOE).

LIMITATION

No trials studied men, clinical fracture data were sparse, methods for estimating harms were heterogeneous, and no trials compared sequential treatments or different durations of drug holidays.

CONCLUSION

Long-term alendronate and zoledronic acid therapies reduce fracture risk in women with osteoporosis. Long-term bisphosphonate treatment may increase risk for rare adverse events, and continuing treatment beyond 3 to 5 years may reduce risk for vertebral fractures. Long-term hormone therapy reduces hip fracture risks but has serious harms.

PRIMARY FUNDING SOURCE

National Institutes of Health and Agency for Healthcare Research and Quality. (PROSPERO: CRD42018087006).

Pharmacological Management of Osteoporosis in Postmenopausal Women: An Endocrine Society* Clinical Practice Guideline

OBJECTIVE

The objective is to formulate clinical practice guidelines for the pharmacological management of osteoporosis in postmenopausal women.

CONCLUSIONS

Evidence from clinical trials and insights from clinical experience with pharmacologic therapies for osteoporosis were critically evaluated in formulating this guideline for the management of postmenopausal osteoporosis. Patient preferences, data on adherence and persistence, and risks and benefits from the patient and provider perspectives were also considered in writing committee deliberations. A consensus by the Writing Committee members was achieved for four management principles: (i) The risk of future fractures in postmenopausal women should be determined using country-specific assessment tools to guide decision-making. (ii) Patient preferences should be incorporated into treatment planning. (iii) Nutritional and lifestyle interventions and fall prevention should accompany all pharmacologic regimens to reduce fracture risk. (iv) Multiple pharmacologic therapies are capable of reducing fracture rates in postmenopausal women at risk with acceptable risk-benefit and safety profiles.

Melatonin Increases Bone Mass around the Prostheses of OVX Rats by Ameliorating Mitochondrial Oxidative Stress via the SIRT3/SOD2 Signaling Pathway

Bone mass loss around prostheses is a major cause of implant failure, especially in postmenopausal osteoporosis patients. In osteoporosis, excess oxidative stress largely contributed abnormal bone remodeling. Melatonin, which is synthesized from the pineal gland, promotes osteoblast differentiation and bone formation and has effectively been used to combat oxidative stress. Thus, we determined if melatonin can inhibit oxidative stress to promote osteogenesis and improve bone mass around prostheses in osteoporosis. In this study, we observed that received melatonin at 50 mg/kg body weight significantly increased periprosthetic bone mass as well as implant fixation intensity in ovariectomized (OVX) rats. Meanwhile, it decreased the expression of oxidative stress markers (NAPDH oxidase 2 and cytochrome c) and enhanced expressing level of the formation markers of bones (alkaline phosphatase, osteocalcin, and osterix) around prostheses compared to that in the control group. Additionally, melatonin decreased hydrogen peroxide- (H₂O₂-) induced oxidative stress and restored the osteogenesis potential of MC3T3-E1 cells. Mechanistically, melatonin clearly increased mitochondrial sirtuin 3 (SIRT3) expression and decreased the ratio of acetylated superoxide dismutase 2 (AC-SOD2)/SOD2 compared to the H₂O₂ group. SIRT3 inhibition counteracted the protective effects of melatonin on oxidative stress and bone formation. Together, the results showed that melatonin ameliorated oxidative stress in mitochondrial via the SIRT3/SOD2 signaling pathway, thereby promoting osteogenesis, improving bone mass around the prostheses, and increasing initial stability. Thus, melatonin might be a suitable candidate to decrease the rate of implant failure and lengthen the lifespan of prostheses after total joint arthroplasty.

Atypical Femur Fractures: Review of Epidemiology, Relationship to Bisphosphonates, Prevention, and Clinical Management

Bisphosphonates (BPs) are highly effective in treating osteoporosis and reducing hip, vertebral, and other fractures by as much as 50% to 70%. However, since 2006, atypical femur fractures (AFFs) emerged as potential side effects of BPs and other treatments. These fractures have unusual radiologic features and occur with little trauma. Public concern has led to a >50% decrease in BP usage. AFFs are rare: for each AFF, >1200 fractures, including 135 hip fractures, are prevented. Case definition criteria were updated by the American Society of Bone and Mineral Research in 2014. Many epidemiologic studies have been reported, and although methodologically challenging, generally support a BP-AFF association. However, the magnitude of the association between BPs and AFFs is uncertain: estimates of relative risk for AFFs among BP users vs nonusers range from 1 to 65 with a meta-analysis estimate of 1.7. Although mechanistic studies have proposed several hypotheses explaining how BPs might decrease bone strength, AFF pathogenesis remains uncertain and cannot explain the paradox of efficacy of reduction of common fractures while increasing risk for rare fractures at one site. There are several consistent risk factors, including Asian race (in North America), femoral bowing, and glucocorticoid use, whereas others remain unclear. Consensus is emerging about strategies to prevent AFFs in BP users (including drug holidays after 5 years' use in some patients). In conclusion, AFFs can be devastating, but even under the most pessimistic assumptions, the benefit/risk ratio is highly positive for BPs, particularly during 3 to 5 years of use. As understanding of AFFs increases, it is becoming increasingly possible to maximize BP benefits while minimizing AFF risk.