Assessment of bone microarchitecture in postmenopausal women on long-term bisphosphonate therapy with atypical fractures of the femur

Atypical Femur Fractures-An Analysis of 69 Patients from 15 Years

Background/Objectives: Bisphosphonates are effective in preventing osteoporotic fractures. However, the risk of atypical femur fractures (AFFs) increases with long-term bisphosphonate use. There are few existing publications on the analysis of clinical outcomes of atypical femur fracture cases in Chinese patients. Our objective was to review the clinical outcomes of AFF cases managed in a tertiary center in Hong Kong, China. Methods: Cases of AFF managed in the Prince of Wales Hospital from 2010 to 2024 were included. Data on demographics, type and duration of bisphosphonate use prior to AFF, fixation method, and mobility 1 year post-operation were retrospectively retrieved. One-way ANOVA was used to compare the duration of use prior to the development of AFF between different types of bisphosphonates. Results: Sixty-nine cases of AFF were included, with a mean age of 73.8 ± 9.7 years. A total of 95.6% of patients had a history of bisphosphonate use, with a mean duration of usage of 6.8 ± 5.6 years prior to the occurrence of AFF. The duration of bisphosphonate use prior to the development of AFF was comparable between alendronate, ibandronate, and a history of using more than one type of anti-resorptive agent. A non-union rate of 5.8% was observed in the current cohort, with 48.2% returning to pre-morbid mobility 1 year post-operation. Conclusions: AFF is more commonly seen in female patients with a history of bisphosphonate use. Considering the high success rate demonstrated in the current cohort, treating AFF with closed reduction followed by fixation with a long cephalomedullary device in dynamic locking together with immediate full-weight-bearing rehabilitation post-operation may be effective.

Update on Atypical Femoral Fractures

➤ Atypical femoral fractures (AFFs) are stress fractures between the lesser trochanter and the metaphyseal flare that are most commonly related to prolonged (3 to 5 years) antiresorptive medication use.➤ An important finding is a visible transverse line in the lateral cortex, known as the "dreaded black line." Complete fractures are transverse and have minimal comminution.➤ Prodromal symptoms including hip, groin, thigh, and knee pain are present in more than one-half of cases and are usually misdiagnosed.➤ Nonoperative treatment for all patients with AFF includes withdrawal of bisphosphonates, assessment for secondary causes of osteoporosis, and optimization of vitamin D and calcium.➤ Incomplete fractures without a visible line can initially be treated nonoperatively with protected weight-bearing.➤ Intramedullary nailing is indicated for complete fractures and incomplete fractures with a visible fracture line. Delayed healing after fixation should be anticipated.➤ Treatment with parathyroid hormone (PTH) analogs (teriparatide and abaloparatide) after AFF prevents other fractures in high-risk patients, but the effect on healing of the fracture is unclear.

Clinical characteristics, densitometric parameters and outcomes of patients with atypical femoral fractures related to bisphosphonate treatment for osteoporosis

PURPOSE

We described the clinical and densitometric characteristics and treatment outcomes of patients who developed atypical femoral fractures (AFF) while on bisphosphonate for osteoporosis.

METHODS

We performed a retrospective cohort study including all adults aged ≥50 years who developed AFF while on bisphosphonates between 1 January 2008 and 31 December 2020, and subsequently managed in the Osteoporosis Centre at Queen Mary Hospital in Hong Kong. A control group of patients who developed fragility hip fractures while on bisphosphonates in the same period was included for comparison. We compared the clinical and densitometric characteristics between the two groups, and described the clinical outcomes for the AFF group.

RESULTS

In total, 75 patients were included (AFF: n = 35; fragility hip fracture: n = 40). All were related to oral bisphosphonates. The AFF group was characterised by a longer duration of bisphosphonate use (median of 5 years), higher bone mineral density (BMD) and more acute neck-shaft angle (all p < 0.05). Following AFF, 8 patients (22.9%) did not receive any subsequent bone-active agents: due to refusal to use an injectable, or BMD out of osteoporotic range. Most of those who received bone-active agents were given teriparatide, followed by raloxifene, and achieved stable BMD. However, subsequent fragility risk remained high. Nonetheless, AFF did not confer excess morbidity and mortality.

CONCLUSION

AFF was characterised by usually long duration of bisphosphonate use, higher BMD and more acute neck-shaft angle. AFF did not confer significant impairment in mobility or mortality. Nonetheless, further research work is necessary to optimise bone health among patients who develop AFF.

Acetabular and sacral insufficiency fractures in a patient with a long-term history of Alendronate consumption; a case report

BACKGROUND

Long-term Bisphosphonate consumption has been reported to be associated with the incidence of atypical or insufficiency fracture, particularly in the proximal femur. We observed a case of acetabular and sacral insufficiency fractures in a patient with a long-term history of Alendronate consumption.

CASE PRESENTATION

A 62-year-old woman was admitted with a complaint of pain in right lower limb following low-energy trauma. The patient had a history of Alendronate consumption for more than 10 years. The bone scan revealed increased radiotracer uptake in the right side of the pelvic, proximal right femur, and sacroiliac joint. The radiographs showed type 1 sacrum fracture, acetabulum fracture with femur head protrusion into the pelvis, quadrilateral surface fracture, fracture of the right anterior column, and right superior and inferior pubic fracture. The patient was treated with total hip arthroplasty.

CONCLUSION

This case highlights the concerns regarding long-term bisphosphonate therapy and its potential complications.

A Quantification Method for Disorganized Bone Components: Application to the Femoral Shaft

Based on the current paradigm, a healthy bone is one with adequate mass without microarchitectural decay. However, these two features may not be sufficient to ensure that a bone is healthy. In addition, components must be correctly assembled and aligned. This ensures "the right amount of bone, at the right place" and thus, an optimal cohesion or interplay between constituents. Disorganization may be an independent contributor to bone abnormalities including fragility fractures. Indeed, many bone diseases may be characterized by the presence of disorganized bone, including osteogenesis imperfecta, hypophosphatasia, and atypical femur fractures (AFFs). Despite its likely importance, currently, there are no tools to quantify disorganization in vivo. We address this unmet need by describing a novel method for quantifying bone disorganization from X-ray images. Disorganization is quantified as variations in the orientation of bone components in relation to a target reference point. True disorganization created by disarranging (misplacing) pixels within the bone served as "gold standard." To further validate the method in clinical settings, we compared disorganization in three groups of femurs: (i) femurs of women with AFFs (n = 9); (ii) fracture-free femurs contralateral to AFFs (n = 9); and (iii) fracture-free femurs from controls (n = 25). There was excellent agreement between measured disorganization and "gold standard," with R ² values ranging from 0.84 to 0.99. Precision error ranged from 1.72% to 4.69%. Disorganization produced by abnormalities associated with AFFs was accurately captured. Disorganization level was lowest in fracture-free control femurs, higher in fracture-free contralateral femurs to AFFs, and highest in femurs with AFFs (all p < 0.0001). Quantification of disorganization, a novel biomarker, may provide novel insights into the pathogenesis of metabolic bone diseases beyond that provided by bone mineral density (BMD) or microarchitecture. We provide evidence that measurement of disorganization is likely to help identify patients at risk for fractures, especially in those poorly explained by BMD or microarchitecture such as AFFs. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Disorganization and Musculoskeletal Diseases: Novel Insights into the Enigma of Unexplained Bone Abnormalities and Fragility Fractures

PURPOSE OF REVIEW

Describe the potential contribution of disorganized tissue to the pathogenesis of bone abnormalities and fractures. Especially, fractures that are unexplained by bone loss (osteoporosis) or structural deterioration.

RECENT FINDINGS

Currently, bone fragility is primarily viewed as due to loss, or decay (osteoporosis). However, it is also acknowledged that this view is limited because it does not explain many fractures or abnormalities such as necrosis, sclerosis, or infarcts. Atypical femoral fractures (AFFs) during antiresorptive therapy are an example. Hence, it is proposed that another distinct mechanism is responsible for bone diseases. A remarkable bone property distinct from mass and decay is the organization (arrangement) of its components. Components must be perfectly assembled or well-stacked to ensure "the right amount of bone, at the right place". Disorganization is an aberration that is conspicuous in many diseases, more so in conditions poorly associated with bone mass and decay such as osteogenesis imperfecta, hypophosphatasia, and AFFs. However, despite the likely critical role of disorganization, this feature has received limited clinical attention. This review focuses on the potential contribution of disorganization to bone in health and diseases. Particularly, we propose that disorganization, by causing ineffective transfer of loads, may produce not only bone abnormalities (pain, necrosis, infarct, sclerosis, delayed healing) but also fractures, especially AFFs or stress fractures. A disorganized element is one that is where it shouldn't be (improperly stacked elements). Hence, disorganization can be measured by quantifying the extent to which a tissue (pixel within an image) is at an incorrect location.

Lower trabecular bone score is associated with an increased incidence of localized femoral periosteal thickening

INTRODUCTION

Femoral localized periosteal thickening (LPT, also termed "beaking") of the lateral cortex often precedes an atypical femoral fracture (AFF). Bisphosphonate (BP) use, glucocorticoid use, and Asian race are major risk factors for developing such fractures. The aim of this study was to determine whether the trabecular bone score (TBS) reflecting the lumbar trabecular microarchitecture was related to LPT in glucocorticoid-treated Japanese patients with autoimmune diseases.

MATERIALS AND METHODS

We retrospectively investigated 111 women with autoimmune diseases treated with prednisolone (PSL) who had undergone both femoral X-ray and dual-energy X-ray absorptiometry of the L1 - L4 lumbar vertebrae and for whom TBS could be evaluated for two or more of these.

RESULTS

Femoral LPT was evident in the X-rays of 18 of 111 patients (16.2%). Higher body mass index (BMI), longer duration of PSL use and longer duration of BP use were significant in patients with LPT compared to those without. The TBS was significantly lower in patients with LPT than in those without (1.314 ± 0.092 vs. 1.365 ± 0.100, p = 0.044); however, the lumbar bone mineral density did not differ significantly (0.892 ± 0.141 vs. 0.897 ± 0.154 g/cm², p = 0.897). TBS was significantly associated with LPT (odds ratio, 0.004; 95% CI, 0 - 0.96; p = 0.048), but not in the multivariate analysis including BMI, duration of PSL use and duration of BP use.

CONCLUSIONS

The TBS was lower in glucocorticoid-treated Japanese women with autoimmune diseases with LPT than in those without LPT, and deteriorated trabecular microarchitecture influenced by longer use of BP and glucocorticoid might be associated with the development of LPT.

The clinical application of high-resolution peripheral computed tomography (HR-pQCT) in adults: state of the art and future directions

High-resolution peripheral computed tomography (HR-pQCT) was developed to image bone microarchitecture in vivo at peripheral skeletal sites. Since the introduction of HR-pQCT in 2005, clinical research to gain insight into pathophysiology of skeletal fragility and to improve prediction of fractures has grown. Meanwhile, the second-generation HR-pQCT device has been introduced, allowing novel applications such as hand joint imaging, assessment of subchondral bone and cartilage thickness in the knee, and distal radius fracture healing. This article provides an overview of the current clinical applications and guidance on interpretation of results, as well as future directions. Specifically, we provide an overview of (1) the differences and reference data for HR-pQCT variables by age, sex, and race/ethnicity; (2) fracture risk prediction using HR-pQCT; (3) the ability to monitor response of anti-osteoporosis therapy with HR-pQCT; (4) the use of HR-pQCT in patients with metabolic bone disorders and diseases leading to secondary osteoporosis; and (5) novel applications of HR-pQCT imaging. Finally, we summarize the status of the application of HR-pQCT in clinical practice and discuss future directions. From the clinical perspective, there are both challenges and opportunities for more widespread use of HR-pQCT. Assessment of bone microarchitecture by HR-pQCT improves fracture prediction in mostly normal or osteopenic elderly subjects beyond DXA of the hip, but the added value is marginal. The prospects of HR-pQCT in clinical practice need further study with respect to medication effects, metabolic bone disorders, rare bone diseases, and other applications such as hand joint imaging and fracture healing. The mostly unexplored potential may be the differentiation of patients with only moderately low BMD but severe microstructural deterioration, which would have important implications for the decision on therapeutical interventions.

Natural history of incomplete atypical femoral fractures in patients after a prolonged and variable course of bisphosphonate therapy-a long-term radiological follow-up

Understanding the natural history of lateral femoral stress fractures helps to guide their management. Improvement in their radiographic characteristics is rare. Progression was generally sequential, most developing an incomplete fracture line before fracture displacement. Stopping bisphosphonates decreased the fracture rate, a feasible management option for lesions without incomplete fracture lines.

INTRODUCTION

Retrospective study evaluating the natural history of lateral femoral stress fractures (FSF) by serial radiography over a variable period of time in a cohort of patients treated for some time with bisphosphonates for osteoporosis, whilst also identifying the fracture response in cases where bisphosphonates were discontinued.

METHODS

The radiographs of 76 consecutive patients (92 femurs) with 161 FSF were reviewed to document their change over time. Femurs were classified into the following: A-normal, B-focal cortical thickening, C-dreaded black line and D-displaced fracture. Bisphosphonate history was recorded.

RESULTS

66.5% FSF showed group stability between the first and last radiographs: group B (79.1%), group C (45.7%). 28.6% progressed, mostly following an ordered sequence starting from group A, progressing to B, then C, before culminating in D. Progression rate was as follows: A-100% (11/11), B-18.3% (21/115), C-40% (14/35). Regression in FSF was uncommon-5.6% (8/161). 34.8% (32/92) sustained displaced fractures. Kaplan-Meier analysis showed statistically significant difference between the groups; median survival (95% CI): A-4189 (-), B-3383.0 (-), C-1807 (0.0-3788.6) and progression to displaced fracture when bisphosphonate had been stopped for at least 6 months. The group without recent bisphosphonates had a lower group progression rate (17.1%, 12/70). Nevertheless, 10.9% (5/46) progressed to displaced fracture. This group also had the highest proportion of stable (77.1%, 54/70) and regressive lesions (5.7%, 4/70).

CONCLUSIONS

In FSF, there is natural progression from normal bone, to focal cortical thickening, to dreaded black line and eventually to displaced fracture. Most lesions persist, remaining static or progressing, especially if a dreaded black line is present and bisphosphonates are continued. Regression is uncommon and more frequent when bisphosphonates are discontinued. Despite stopping bisphosphonates, there remains a 10.9% risk of progression to displaced fracture.

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.

Trabecular Bone Score and Hip Structural Analysis in Patients With Atypical Femur Fractures

Bisphosphonate use has declined dramatically in recent years, partly because of fear of rare side effects like atypical femur fractures (AFFs). It is therefore desirable to have a diagnostic method to identify those at risk of AFF to prevent this serious complication. We compared trabecular microarchitecture and hip geometry between 30 patients with AFF and 141 controls of similar age and sex, using bisphosphonates. Trabecular bone score (TBS) and hip structural analysis (HSA) were used to assess trabecular microarchitecture and macroscopic hip geometry from dual-energy X-ray absorptiometry images of the lumbar spine and hip, respectively. General characteristics, TBS, and HSA were compared between patients with AFF and controls using Student's t tests and chi-square statistics. Associations between AFF and TBS and femur geometric characteristics by HSA were adjusted for sex, age, height, weight, ethnicity, duration of bisphosphonate use, and glucocorticoid use. Additionally, the analysis of TBS was adjusted for lumbar spine bone mineral density and the time difference between dual-energy X-ray absorptiometry scanning and the diagnosis of AFF. Patients with AFF had significantly higher body mass index than controls, had used bisphosphonates longer, and glucocorticoids and proton pump inhibitors more frequently. Sex-specific T-score was significantly higher in patients with AFF at the lumbar spine (p = 0.004), but not at the femoral neck (p = 0.190) after adjustment for age, height, and weight. TBS did not differ significantly between patients with AFF and controls. Neither neck shaft angle nor any geometric variables at the femoral shaft measured by HSA differed between patients with AFF and controls. At the narrow neck, patients with AFF had lower buckling ratio and higher centroid position, consistent with a lower risk of classical fragility hip fractures. The findings at narrow neck and higher bone mineral density might be explained by the fact that the majority of patients with AFF used bisphosphonates to prevent glucocorticoid-induced osteoporosis. Based on our results, TBS and HSA do not appear to have value in detecting patients at risk of AFF.

Current Understanding of Epidemiology, Pathophysiology, and Management of Atypical Femur Fractures

PURPOSE OF REVIEW

To summarize reports published since the 2013 American Society of Bone and Mineral Research Task Force Report on atypical femoral fractures (AFF).

RECENT FINDINGS

The absolute incidence of AFFs remains low. AFFs are primarily associated with prolonged bisphosphonate (BP) exposure, but have also been reported in unexposed patients and those receiving denosumab for osteoporosis and metastatic bone disease. Asians may be more susceptible to AFFs. Lateral femoral bowing and varus hip geometry, which increase loading forces on the lateral femoral cortex, may increase AFF risk. Altered bone material properties associated with BP therapy may predispose to AFFs by permitting initiation and increasing propagation of micro-cracks. Relevant genetic mutations have been reported in patients with AFFs. Single X-ray absorptiometry femur scans permit early detection of incomplete and/or asymptomatic AFFs. Orthopedists recommend intramedullary rods for complete AFFs and for incomplete, radiologically advanced AFFs associated with pain and/or marrow edema on MRI. Teriparatide may advance AFF healing but few data support its efficacy. Greater understanding of biological and genetic predisposition to AFF may allow characterization of individual risk prior to initiating osteoporosis therapy and help allay fear in those at low risk for this complication, which remains rare in comparison to the osteoporotic fractures prevented by antiresorptive therapy.

Predisposing factors associated with atypical femur fracture among postmenopausal Korean women receiving bisphosphonate therapy: 8 years' experience in a single center

The risk factors for atypical femur fracture in patients exposed to bisphosphonates for at least 1 year were examined. Prolonged and continuous use of bisphosphonates, long-term use of glucocorticoids, and a higher body mass index were associated with increased risk of atypical femur fracture.

INTRODUCTION

The purpose of the present study is to determine whether rheumatoid arthritis (RA) and other clinical factors are associated with an increased risk of bisphosphonate (BP)-related atypical femur fracture (AFF).

METHODS

A retrospective nested case-control study of patients who had taken BPs for at least 1 year was conducted. Patients with AFF were identified by reviewing surgical and radiographic records. Three controls with no history of AFFs were randomly selected and age- and sex-matched to each patient with AFFs. Cox proportional hazard models were used to analyze the independent contribution of risk factors to BP-related AFF.

RESULTS

Among the 35,104 patients prescribed BPs for at least 1 year, 43 females (mean age, 68 years) suffered AFFs (0.12%). Patients with AFFs were exposed to BPs for a mean of 7.3 years. Patients with AFFs were exposed to BPs for longer than those without AFFs and continued treatment without a drug holiday. More patients with AFF than controls had taken glucocorticoids and disease-modifying anti-rheumatic drugs. Multivariate Cox regression analyses estimated that long-term use of glucocorticoids, prolonged exposure to BP without cessation, and every 1 kg/m² increase in the body mass index (BMI) increased the hazard ratio for AFFs by 3.0, 5.2, and 1.2, respectively.

CONCLUSIONS

Prolonged and continuous use of BPs, long-term use of glucocorticoids, and a higher BMI increase the risk of AFFs. Switching long-term BP and glucocorticoid users to other bone-protective agents should be considered.

Hypogonadal men with type 2 diabetes mellitus have smaller bone size and lower bone turnover

INTRODUCTION

Both hypogonadism and type 2 diabetes mellitus (T2D) are associated with increased fracture risk. Emerging data support the negative effect of low testosterone on glucose metabolism, however, there is little information on the bone health of hypogonadal men with diabetes. We evaluated the bone mineral density (BMD), bone geometry and bone turnover of hypogonadal men with T2D compared to hypogonadal men without diabetes.

MATERIALS AND METHODS

Cross-sectional study, men 40-74years old, with average morning testosterone (done twice) of<300ng/dl. Areal BMD (aBMD) was measured by DXA; volumetric BMD (vBMD) and bone geometry by peripheral-quantitative-computed-tomography; serum C-telopeptide (CTX), osteocalcin, sclerostin and sex hormone-binding globulin (SHBG) by ELISA, testosterone and 25-hydroxyvitamin D (25OHD) by automated immunoassay and estradiol by liquid-chromatography/mass-spectrometry. Groups were compared by ANOVA adjusted for covariates.

RESULTS

One-hundred five men, 49 with and 56 without diabetes were enrolled. Adjusted vBMD at 38% tibia was higher in diabetic than non-diabetic men (857.3±69.0mg/cm³ vs. 828.7±96.7mg/cm³, p=0.02). Endosteal (43.9±5.8mm vs. 47.1±7.8mm, p=0.04) and periosteal (78.4±5.0mm vs. 81.3±6.5mm, p=0.02) circumferences and total area (491.0±61.0mm² vs. 527.7±87.2mm², p=0.02) at 38% tibia, were lower in diabetic men even after adjustments for covariates. CTX (0.25±0.14ng/ml vs. 0.40±0.19ng/ml, p<0.001) and osteocalcin (4.8±2.8ng/ml vs. 6.8±3.5ng/ml, p=0.006) were lower in diabetic men; there were no differences in sclerostin and 25OHD. Circulating gonadal hormones were comparable between the groups.

CONCLUSION

Among hypogonadal men, those with T2D have higher BMD, poorer bone geometry and relatively suppressed bone turnover. Studies with larger sample size are needed to verify our findings and possible even greater risk for fractures among hypogonadal diabetic men.

Bisphosphonates in the treatment of osteoporosis: a review of skeletal safety concerns

The use of bisphosphonates in treatment of osteoporosis declined significantly over the past decade. There is currently great concern, among patients and physicians, about two potential skeletal adverse effects associated with bisphosphonates- jaw osteonecrosis and atypical femur fractures. This has become a major public health issue since untreated osteoporosis carries a significant burden in terms of fracture-related morbidity and mortality, and bisphosphonates, considered first-line therapy for osteoporosis, have established efficacy in fracture and mortality reduction. Areas covered: In this review we discuss current literature on osteonecrosis of the jaw and atypical femur fractures in patients with osteoporosis treated with bisphosphonates, including case definition, pathogenesis, epidemiology, risk factors, clinical presentation, management and prevention. We conducted a literature search using PubMed and PubMed Central, using the search terms 'bisphosphonates', 'osteonecrosis of the jaw', and 'atypical fractures'. We selected relevant articles including meta-analyses, clinical trials, observational studies, and major society guidelines published between 2010 and 2016, to be included in this review. A few articles published prior to 2010 were also included as references. Expert commentary: The rare skeletal side effects of bisphosphonates should not preclude their use in patients with osteoporosis and high fracture risk, as benefits significantly outweigh the risks.

Influence of bisphosphonate therapy on bone geometry, volumetric bone density and bone strength of femoral shaft in postmenopausal women with rheumatoid arthritis

BACKGROUND

There is evidence that postmenopausal women with rheumatoid arthritis (RA) on glucocorticoid (GC) therapy and bisphosphonate (BP) have an increased risk for atypical subtrochanteric and atypical diaphyseal femoral fracture (AFF). The underlying mechanism has not been elucidated so far. Using peripheral quantitative computed tomography (pQCT), the aim of the present study was to compare bone geometry, volumetric bone mineral density (vBMD) and bone strength of femoral shaft in BP-treated and BP-naïve postmenopausal women with RA.

METHODS

Prospective cross-sectional pQCT scans were taken at 33 % of total femur of BP-treated and BP-naïve RA patients. Bone parameters of the two groups were compared and correlated to disease characteristics and muscle cross-sectional area (CSA).

RESULTS

A total of 60 consecutive postmenopausal RA patients, 20 with BP therapy and 40 BP-naïve, were included in the study. The median age of the subjects was 63.5 years (range 48-85 years), and median disease duration (RA) was 12.0 years (range 2-47 years). Height and weight of the patients of the two groups were comparable. Women in the BP group were on average 4.3 years older (p = 0.044), and duration since menopause was on average 5.76 years longer (p = 0.045). In the BP group, there was a 13.31 % reduced muscle cross-sectional area around the proximal thigh (p = 0.013); cortical CSA was smaller by 5.3 % (p = 0.043); however, total and medullary CSA, as well as cortical vBMD and the polar bone stress-strain index of the femoral shaft were similar in the two groups. In regression analysis, age, time since menopause and muscular CSA were significant factors determining cortical CSA, cortical thickness and femoral index (p < 0.05). Regression model showed no significant effect of BP therapy on bone geometry and density of the femoral diaphysis at 33 %.

CONCLUSION

Differences in cortical CSA between BP-treated and BP-naïve postmenopausal RA patients were found to be associated only with differences in age, time since menopause and muscle cross-sectional area around the proximal thigh. In interpreting our results, it should be kept in mind that BP was given only to patients with increased fracture risk. This fact might have a confounding effect on our findings of differences between the two groups.

Incidence of Atypical Femur Fractures in Cancer Patients: The MD Anderson Cancer Center Experience

Atypical femoral fractures (AFFs) are rare adverse events attributed to bisphosphonate (BP) use. Few cases of AFF in cancer have been described; the aim of this study is to identify the incidence and risk factors for AFF in a large cancer center. This retrospective study was conducted at the MD Anderson Cancer Center. The incidence rate of AFF among BP users was calculated from January 1, 2004 through December 31, 2013. The control group (n = 51) included 2 or 3 patients on BPs matched for age (≤1 year) and gender. Logistic regression analysis was used to assess the relationship between clinical characteristics and AFF. Twenty-three AFF cases were identified radiographically among 10,587 BP users, the total BP exposure was 53,789 months (4482 years), and the incidence of AFF in BP users was 0.05 cases per 100,000 person-years. Meanwhile, among 300,553 patients who did not receive BPs there were 2 cases of AFF as compared with the 23 cases noted above. The odds ratio (OR) of having AFF in BP users was 355.58 times higher (95% CI, 84.1 to 1501.4, p < 0.0001) than the risk in non-BP users. The OR of having AFF in alendronate users was 5.54 times greater (OR 5.54 [95% CI, 1.60 to 19.112, p = 0.007]) than the odds of having AFF among other BP users. Patients who were on zoledronic acid (ZOL) had smaller odds of developing AFF compared with other BP users in this matched case control sample. AFFs are rare, serious adverse events that occur in patients with cancer who receive BP therapy. Patients with cancer who receive BPs for prior osteoporosis therapy or for metastatic cancer are at higher risk of AFF. © 2016 American Society for Bone and Mineral Research.

Atypical Femoral Fractures-Ongoing and History of Bone-Specific Therapy, Concomitant Diseases, Medications, and Survival

Although atypical femoral fractures (AFFs) are generally rare events; several studies have indicated a potential link between AFF and long-term bone-specific therapies (BSTs). The aim of this study was to analyze the frequency of AFF and potential associations with prior or ongoing BST. A total of 8851 Caucasian female and male patients with de novo hip fractures treated in the largest Austrian level 1 trauma center from 2000 to 2013 were selected. Of the total, 194 patients with a de novo low-traumatic subtrochanteric or shaft fractures were identified: 35 atypical and 159 typical fractures. Of these patients, concomitant diseases, medication, previous fractures, and survival data were retrieved and analyzed. Female patients in both groups were significantly older. The median survival was significantly shorter in patients with AFF (9 vs 18 months; p < 0.0001). Cardiovascular disease, sarcopenia, chronic kidney disease, type 2 diabetes, smoking (past or current history), and prevalent fragility fractures were more frequent in AFF patients, as well as the concomitant use of phenprocoumon, furosemide, and sulfonylurea. Although the number of patients with current BST was less in (14.5%) both groups, more patients in the AFF group were previously treated with BST (71% vs 49%; p = 0.016), and they received these therapies for a longer time period. A combination of severe comorbidities, long-term pharmaceutical therapies, and a history of previous or ongoing BST was associated with an increased individual risk for AFF.

[Clinical heterogeneity of atypical fractures during prolonged use of bisphosphonates--risk factors and bone turnover markers]

We describe four cases of atypical femoral fractures treated at the Department of Endocrinology, Hospital de Clínicas, Federal University of Paraná (SEMPR) which, although characteristic of this type of fracture, presented clinical peculiarities that should be considered and serve as a warning in these patients, such as: late diagnosis with maintenance of bisphosphonates; absence of co-morbidities with excellent result; failure of fracture healing; use of anabolic medication after the fracture and the use of bone turnover markers at the follow up.

Pathological pelvic fracture following long-term bisphosphonate use in a 63-year-old woman

A 63-year-old woman presented with a low energy pelvic fracture, which showed no signs of healing. Initial fractures were to the right hemipelvis, later followed by a right fractured neck of femur. We present a complicated patient journey, management dilemmas and highlight the growing concern with long-term bisphosphonate treatment.

Vanillic acid exerts oestrogen-like activities in osteoblast-like UMR 106 cells through MAP kinase (MEK/ERK)-mediated ER signaling pathway

Sambucus williamsii Hance (SWH) has been used for treatment of bone and joint disease in China for thousands of years. Our previous study showed that SWH extract and its bioactive fraction could effectively prevent oestrogen-deficiency induced bone loss in ovariectomized mice. The present study aimed to study the bone protective effects of vanillic acid (VA), a phenolic acid isolated from the bioactive fraction of SWH, and to characterize the signaling pathways that mediated its actions in rat osteoblast-like UMR 106 cells. VA significantly stimulated proliferation, alkaline phosphatase (ALP) activities as well as significantly altered the mRNA expression of genes involved in osteoblast functions and osteoclastogenesis in UMR 106 cells. Co-treatment of UMR 106 cells with 10(-6)M ICI182,780 (a specific oestrogen receptor (ER) antagonist) abolished the stimulatory effects of VA on osteoblast proliferation and ALP activities, suggesting the role of ER in mediating its actions. However, VA (10(-12) to 10(-6)M) failed to bind to ERα or ERβ and did not activate oestrogen response element (ERE)-luciferase activities via ERα or ERβ in UMR 106 cells. In contrast, 10(-10) and 10(-8)M of VA induced the phosphorylation of MEK 1/2, ERK1/2 and ERα at Ser118 residue in UMR 106 cells, suggesting that MAP kinase-mediated pathway is involved in mediating its actions. Taken together, our results indicated that VA is a bioactive compound in SWH that exerts stimulatory effects in osteoblast-like cells via non-genomic, but not classical, ER signaling pathway.

Weekly Teriparatide for Delayed Unions of Atypical Subtrochanteric Femur Fractures

Introduction

The occurrence of atypical femur fractures (AFFs) in patients on prolonged bisphosphonate treatment has been gaining medical attention, but the use of pharmacotherapy for these fractures has not been explored in detail. The authors describe a case of AFFs successfully treated with once-weekly administration of 56.5 μg teriparatide (TPTD).

Case Presentation

The patient was a 74-year-old female patient who had been taking alendronate for approximately 6 years and who suffered with a fall while walking. X-rays revealed a subtrochanteric right femur fracture. The contralateral femur showed cortical thickening and a transverse radiolucent fracture line. Based on these specific features, the patient was diagnosed with AFF. The patient underwent osteosynthesis with intramedullary nailing for the right fracture. Alendronate treatment was discontinued. Low-intensity pulsed ultrasonography therapy did not affect the healing of the fracture with delayed union, even after 3 months of application. Prophylactic osteosynthesis was performed for the subtrochanteric left femur. Bone tissue collected from the left fracture site during surgery showed severe suppression of bone turnover. Union of bilateral femurs was achieved after 3 months of a once-weekly administration of TPTD.

Conclusion

Once-weekly TPTD treatment is shown to be beneficial for improving the healing of AFFs showing delayed union.

Electronic supplementary material

The online version of this article (doi:10.1007/s13554-014-0013-5) contains supplementary material, which is available to authorized users.