Atypical Femoral Fractures: Transverse Morphology at Lateral Cortex Is a Critical Feature

In 2010, the American Society for Bone and Mineral Research (ASBMR) task force defined major and minor features to assist in the case finding and reporting of atypical femoral fractures (AFFs). One major feature that was proposed was a “transverse or short oblique configuration.” Our primary aim was to compare the conventional overall fracture morphology (OFM) with its associated angle (OFMA) and our proposed lateral cortical fracture angle (LCFA) in the assessment of fracture configuration in suspected AFFs and non‐AFFs. The radiographs of 79 patients with AFFs and 39 patients with non‐AFFs were each analyzed by two blinded reviewers to obtain the OFM, OFMA, and LCFA. Using the overall fracture morphology to assess the suspected AFFs resulted in discordance between reviewers in 18 cases (22.8%), of which 5 (6.3%) were discordant between short oblique (>30° to 60°) and long oblique (>60° to 90°) configurations, therefore affecting their classifications as AFFs. By assessing only the critical component within the lateral cortex, all the suspected AFFs fell well within the classification as transverse fractures with a mean LCFA of 4.8° (range 0.3 to 18.0, SD = 4.23). The inter‐reader variability was also lower for LCFA versus OFMA (4.1° versus 6.9°, p = 0.001) when used to assess AFFs. Fracture angles were significantly different in AFFs versus non‐AFFs regardless of whether the OFMA or LCFA methodology was employed, but the greater difference associated with LCFA suggests its greater discriminating power. When LCFA was used in conjunction with 0° to 30° as the criteria for transverse morphology, all the AFFs and non‐AFFs were correctly classified. By using a standardized and precise method in measuring the fracture angle, specifically using only the component of the lateral cortex and limiting to truly transverse fractures, ie, between 0° and 30°, the LCFA is a robust and accurate method to assess the fracture morphology in suspected AFFs. © 2014 American Society for Bone and Mineral Research.     

The Sydney AFF Score: A Simple Tool to Distinguish Females Presenting With Atypical Femur Fractures Versus Typical Femur Fractures

Atypical femur fractures (AFF) are a rare but serious complication of long-term bisphosphonate use. Although clearly defined by ASBMR criteria, a proportion of patients with AFFs may go unrecognized and the use of qualitative fracture criteria may lead to uncertainty in AFF diagnosis, with significant therapeutic implications. A score that rapidly and accurately identifies AFFs among subtrochanteric femur fractures using quantitative, measurable parameters is needed. In a retrospective cohort of 110 female patients presenting with AFFs or typical femur fractures (TFFs), multiple logistic regression and decision tree analysis were used to develop the Sydney AFF score. This score, based on demographic and femoral geometry variables, uses three dichotomized independent predictors and adds one point for each: (age ≤80 years) + (femoral neck width <37 mm) + (lateral cortical width at lesser trochanter ≥5 mm), (score, 0 to 3). In an independent validation set of 53 female patients at a different centre in Sydney, a score ≥2 demonstrated 73.3% sensitivity and 69.6% specificity for AFF (area under the receiver-operating characteristic curve [AUC] 0.775, SE 0.063) and remained independently associated with AFF after adjustment for bisphosphonate use. The Sydney AFF score provides a quantitative means of flagging female patients with atraumatic femur fractures who have sustained an AFF as opposed to a TFF. This distinction has clear management implications and may augment current ASBMR diagnostic criteria. © 2021 American Society for Bone and Mineral Research (ASBMR).     

Incidence and Characteristics of Atypical Femoral Fractures: Clinical and Geometrical Data

Despite the multitude of studies published on atypical femoral fractures (AFFs), a profile for patients at risk does not exist. This study aimed first at estimating AFF incidence over a 19‐month‐period in Quebec City using the ASBMR Task force criteria to define AFF. The medical records of patients hospitalized for hip or femoral fracture between June 1, 2009, and December 31, 2010, were reviewed. Thirty‐six cases of atypical fractures were identified during the 19‐month period, representing an AFF incidence of 7.0 (range, 4.7 to 9.3) cases per 100,000 person‐years. In the second part of the study, data regarding the characteristics suspected of increasing the risks of AFF were collected from medical and pharmacological records, proximal femur radiographs, and patient interviews. The data regarding each patient with an AFF during years 2008‐2011 were compared to two controls with a hip or femoral fragility fracture or a traumatic fracture, paired for age and sex. Twenty patients with AFF were added to the 36 patients with AFF selected in the first part, thereby 56 patients with AFF were investigated. The association between the occurrence of AFF and bisphosphonates (BPs) use was proven statistically significant in multivariate analysis, odds ratio (OR) = 10.39 (95% CI, 2.22 to 48.58; p = 0.0029). Compared to controls, patients with AFF had excessive femoral offset (43.1 mm versus 38.3 mm, p = 0.0007), proximal femoral neck angle in varus (128.9 degrees versus 134.0 degrees, p < 0.0001), and had greater proximal cortical thickness. This retrospective study confirms the low incidence of AFF, confirms its significant association with exposure to BPs, and reveals the possible contribution of proximal femoral geometry in AFF occurrence. © 2016 American Society for Bone and Mineral Research.     

Atypical fracture of the tibial diaphysis associated with bisphosphonate therapy: A case report

Atypical subtrochanteric femoral shaft fractures (AFFs) have recently emerged as a potential long-term complication of bisphosphonate therapy. In 2010, the American Society for Bone and Mineral Research (ASBMR) Task Force published a definition for AFF consisting of 5 major and 7 minor features. Little attention has so far been paid to the possibility that bisphosphonate-associated atypical fractures may also involve the diaphysis of other long bones. We report here the case of a patient on long-term bisphosphonate therapy who presented a diaphyseal tibial insufficiency fracture fulfilling all the major criteria (except for the location), and a number of the minor criteria of an atypical fracture. Our case report suggests the need for greater awareness of the possibility of atypical fractures at other sites, particularly in weight-bearing long bones other than the femur, and suggests that long-term bisphosphonate therapy may also contribute to the occurrence of these atypical fractures.     

Assessment of Bone Microarchitecture in Postmenopausal Women on Long‐Term Bisphosphonate Therapy With Atypical Fractures of the Femur

Reports of atypical femoral fractures (AFFs) in patients receiving long‐ term bisphosphonate therapy have raised concerns regarding the genesis of this rare event. Using high‐resolution peripheral quantitative computed tomography (HR‐pQCT), we conducted a study to evaluate bone microarchitecture in patients who had suffered an AFF during long‐term bisphosphonate treatment. The aim of our study was to evaluate if bone microarchitecture assessment could help explain the pathophysiology of these fractures. We compared bone volumetric density and microarchitectural parameters measured by HR‐pQCT in the radius and tibia in 20 patients with AFFs with 35 postmenopausal women who had also received long‐term bisphosphonate treatment but had not experienced AFFs, and with 54 treatment‐naive postmenopausal women. Control groups were similar in age, body mass index (BMI), and bone mineral density (BMD). Mean age of the 20 patients with AFFs was 71 years, mean lumbar spine T‐score was ?2.2, and mean femoral neck T‐score was ?2. Mean time on bisphosphonate treatment was 10.9 years (range, 5–20 years). None of the patients had other conditions associated with AFFs such as rheumatoid arthritis, diabetes or glucocorticoid use. There were no statistically significant differences in any of the parameters measured by HR‐pQCT between postmenopausal women with or without treatment history and with or without history of atypical fractures. We could not find any distinctive microarchitecture features in the peripheral skeleton of women who had suffered an atypical fracture of the femur while receiving bisphosphonate treatment. This suggests that risk of developing an atypical fracture is not related to bone microarchitecture deterioration. Our results indicate that there may be other individual factors predisposing to atypical fractures in patients treated with bisphosphonates, and that those are independent of bone microarchitecture. In the future, identification of those factors could help prevent and understand the complex physiopathology of these rare events. © 2014 American Society for Bone and Mineral Research.     

Atypical Subtrochanteric and Diaphyseal Femoral Fractures: Second Report of a Task Force of the American Society for Bone and Mineral Research

Bisphosphonates (BPs) and denosumab reduce the risk of spine and nonspine fractures. Atypical femur fractures (AFFs) located in the subtrochanteric region and diaphysis of the femur have been reported in patients taking BPs and in patients on denosumab, but they also occur in patients with no exposure to these drugs. In this report, we review studies on the epidemiology, pathogenesis, and medical management of AFFs, published since 2010. This newer evidence suggests that AFFs are stress or insufficiency fractures. The original case definition was revised to highlight radiographic features that distinguish AFFs from ordinary osteoporotic femoral diaphyseal fractures and to provide guidance on the importance of their transverse orientation. The requirement that fractures be noncomminuted was relaxed to include minimal comminution. The periosteal stress reaction at the fracture site was changed from a minor to a major feature. The association with specific diseases and drug exposures was removed from the minor features, because it was considered that these associations should be sought rather than be included in the case definition. Studies with radiographic review consistently report significant associations between AFFs and BP use, although the strength of associations and magnitude of effect vary. Although the relative risk of patients with AFFs taking BPs is high, the absolute risk of AFFs in patients on BPs is low, ranging from 3.2 to 50 cases per 100,000 person‐years. However, long‐term use may be associated with higher risk (～100 per 100,000 person‐years). BPs localize in areas that are developing stress fractures; suppression of targeted intracortical remodeling at the site of an AFF could impair the processes by which stress fractures normally heal. When BPs are stopped, risk of an AFF may decline. Lower limb geometry and Asian ethnicity may contribute to the risk of AFFs. There is inconsistent evidence that teriparatide may advance healing of AFFs. © 2014 American Society for Bone and Mineral Research.     

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.

Summary

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.

     

Incidence and demography of femur fractures with and without atypical features

The case definition, community incidence, and characteristics of atypical femoral shaft fractures (FSFs) are poorly understood. This retrospective study utilized electronic medical records and radiograph review among women ≥50 years of age and men ≥65 years of age from January 1996 to June 2009 at Kaiser Permanente Northwest to describe the incidence rates and characteristics of subgroups of femur fractures. Fractures were categorized based on the American Society for Bone and Mineral Research (ASBMR) as atypical fracture major features (AFMs) (low force, shaft location, transverse or short oblique, noncomminuted) and AFMs with additional minor radiograph features (AFMms) (beaking, cortical thickening, or stress fracture). There were 5034 fractures in the study. The incidence rates of FSFs (without atypical features) and AFMs appeared flat (cumulative incidence: 18.2 per 100,000 person‐years, 95% CI = 16.0–20.7; 5.9 per 100,000 person‐years, 95% CI = 4.6–7.4; respectively) with 1,271,575 person‐years observed. The proportion of AFMs that were AFMms increased over time. Thirty percent of AFMs had any dispensing of a bisphosphonate prior to the fracture, compared to 15.8% of the non‐atypical FSFs. Years of oral glucocorticosteroid dispensing appeared highest in AFM and AFMm fractures. Those with AFMs only were older and had a lower frequency of bisphosphonate dispensing compared to those with AFMms. We conclude that rates of FSFs, with and without atypia, were low and stable over 13.5 years. Patients with only AFMs appear to be different from those with AFMms; it may be that only the latter group is atypical. There appear to be multiple associated risk factors for AFMm fractures. © 2012 American Society for Bone and Mineral Research.     

Screening for Atypical Femur Fractures Using Extended Femur Scans by DXA

Atypical femur fractures (AFFs) are a rare but serious complication associated with the use of antiresorptive drugs such as bisphosphonates. Assessment of incomplete AFFs on extended femur scans by dual‐energy X‐ray absorptiometry (DXA) may prevent the development of complete fractures. The aim of this study was to evaluate the potential of extended femur scans by DXA as a screening tool for incomplete AFFs. From June 2014 until September 2016, extended femur scans were routinely performed in all consecutive patients undergoing DXA scanning who had used bisphosphonates or denosumab at any given moment in the previous year. When “beaking” was found, defined as a localized periosteal or endosteal thickening of the lateral cortex, a radiograph of the femur was performed to confirm incomplete AFF. Beaking was detected in 12 of 282 patients (4.3%) with extended scans of both femora. In 9 patients (3.2%), beaking corresponded with the radiological presence of incomplete AFFs, of whom 4 already had an X‐ray made because of a previous complete AFF of the other leg. Five patients (1.8%) were newly diagnosed with 6 yet unknown incomplete AFFs. No additional X‐ray was performed in 2 patients because of loss of follow‐up. Beaking was explained by known soft tissue calcifications in 1 patient. The positive predictive value of beaking on extended femur scan was 83.3% in our study. Three cases in whom the new diagnosis of incomplete AFF has affected medical and surgical treatment are further discussed to illustrate the relevance of early detection. We conclude that extended femur scans by DXA can detect incomplete AFFs in patients on antiresorptive treatment and should therefore be considered a clinically relevant screening tool because early identification of AFFs has therapeutic consequences. © 2017 American Society for Bone and Mineral Research.     

Mortality After Atypical Femoral Fractures: A Cohort Study

Although osteoporotic fracture rates can be reduced by bisphosphonates, prolonged therapy is associated with higher risk of atypical femoral fractures. Ordinary fragility fractures are linked to high mortality rates. We aimed to determine whether atypical femoral fractures also confer excess mortality. Radiographs were reviewed for all patients aged ≥55 years who had experienced a subtrochanteric or femoral shaft fracture in Sweden in 2008 to 2010. The fractures were classified as either atypical or ordinary. Data on medication use, coexisting conditions, and date of death were obtained from national registers. We estimated multivariable‐adjusted relative risks of death after atypical femoral fractures compared with ordinary subtrochanteric or femoral shaft fractures and calculated age‐ and sex‐standardized mortality ratios (SMRs) for atypical and ordinary fractures compared with the population average. During a mean of 4 years of follow‐up, 39 of 172 (23%) patients with an atypical fracture had died compared with 588 of 952 (62%) with an ordinary fracture, corresponding to a relative risk of 0.51 (95% confidence interval [CI] 0.38–0.68). The lower risk was evident in both users and nonusers of bisphosphonates. No patient with atypical fracture died in the first year after fracture. Individuals with an ordinary fracture had a higher mortality risk than the general population (SMR = 1.82; 95% CI 1.69–1.99), but no excess risk was found in patients with atypical fracture (SMR = 0.92; 95% CI 0.65–1.26). We conclude that in contrast to ordinary subtrochanteric and femoral shaft fractures, atypical femoral fractures are not associated with excess mortality. © 2015 American Society for Bone and Mineral Research.     

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.     

Periprosthetic Atypical Femoral Fractures Exist: A Retrospective Study at a Single Institution. Prevalence on 115 Periprosthetic Femoral Fractures Around a Primary Hip Stem

BackgroundSome periprosthetic femoral fractures (PFFs) present history and radiographic aspect consistent with an atypical femoral fracture (AFF), fulfilling the criteria for AFF except that PFFs by themselves are excluded from the diagnosis of AFFs. The aim of this study is to evaluate in a single institution series of PFFs if any of them could be considered a periprosthetic atypical femoral fracture (PAFF), and their prevalence.MethodsSurgical records were searched for PFFs around a primary hip stem from January 2013 to December 2019. Cases were classified according to Vancouver classification. Demographic and medical history was extracted. Fisher’s exact test was used for statistical analysis.ResultsOne hundred fifteen PFFs were identified, 59 of them were type B1 and 16 were type C. Radiographs and medical records were available for all patients. Twenty-four patients (32%) have been treated with bisphosphonates (BPs) for longer than 4 years. Four patients presented a fracture with characteristics of PAFF. When enlarged to all PFFs of the series, no other PAFF was found: prevalence of PAFFs was 5.3% for type B1 and C cases and 3.5% for all surgically treated PFFs. Statistical significative difference between PAFFs and PFFs was found for prolonged BP assumption and for the level of fracture clear of the stem.ConclusionFracture with characteristics of AFFs can also happen over a prosthetic stem, configuring themselves as PAFFs, and they are related to prolonged BP use. As a correct diagnosis is mandatory for proper treatment, a revision of criteria for AFFs should be considered, accepting that PAFFs exist.     

Treatment status and radiographic features of patients with atypical femoral fractures

Background

The Japanese Orthopaedic Association (JOA) has been surveying approximately 3000 orthopedic surgery hospitals and clinics with inpatient facilities nationwide to collect information on atypical femoral fractures (AFFs) and patient characteristics since 2010. The present study aims to examine radiographic images and clarify the relationship between radiographic and patient characteristics of patients with AFF and treatment status.

Fracture Risk Following an Atypical Femoral Fracture

Atypical femoral fractures (AFFs) occurring during the course of osteoporosis treatment usually lead to discontinuation of anti-resorptive (AR) drugs. However, the risk of fracture after an AFF is unknown. We conducted a follow-up study of patients with AFF matched 1:3 for age and gender with patients with a peripheral major osteoporotic fracture (pMOF), in the setting of a fracture liaison service, to investigate the incidence of subsequent low-trauma fractures. Fifty-five patients with AFF (95% women, age [mean ± standard deviation] 75 ± 10 years, 89% exposed to AR drugs), followed for 6.2 ± 3.7 years, were compared to 165 matched controls with a pMOF (hip 85%) followed for 4.3 ± 2.6 years. During the follow-up, 38% of patients in the AFF group and 16% in the pMOF group received AR therapies. Continuation of AR drugs after an AFF was associated with contralateral AFF in 27% of subjects. The risks of new low-trauma, major osteoporotic and imminent (within 2 years) fractures, were similar between the two groups: incidence rate ratio (95% confidence interval [CI]) of subsequent fracture following AFF relative to pMOF, 1.30 (95% CI, 0.82–2.04), 1.28 (95% CI, 0.74–2.15), and 1.11 (95% CI, 0.54–2.15), respectively. Moreover, the risk of sustaining multiple fractures per participant was significantly increased among patients with AFF compared to pMOF (hazard ratio 1.48 [95% CI, 1.00–2.19]; p = 0.049). When taking mortality into account, the risk of subsequent fractures tended to be higher in the AFF group (sub-hazard ratio 1.42 [95% CI, 0.95–2.12]). In conclusion, patients who sustained an AFF are at high risk of subsequent fragility fractures, at least equal or even greater to the risk observed after a pMOF. However, continuation of AR drugs increases the risk of contralateral AFF. Therefore, optimal modalities for secondary fracture prevention after AFF require further evaluation. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).     

Responses to Treatment With Teriparatide in Patients With Atypical Femur Fractures Previously Treated With Bisphosphonates

If oversuppression of bone turnover explained the association between bisphosphonate use and atypical subtrochanteric femur fractures (AFF), this could be reversed with anabolic treatment such as teriparatide. We conducted a prospective, open‐label study in patients previously treated with bisphosphonates who sustained AFF, examining the response to 24‐month treatment with teriparatide on bone mineral density (BMD), trabecular bone score (TBS), bone turnover markers (BTM), and fracture healing as well as quantitative histomorphometry. We studied 14 patients. Baseline BMD, BTM, and TBS varied widely. On initial bone biopsies, 12 of 14 patients showed tetracycline labels, but mineralizing surface/bone surface was below published normal values in all but 2. Lumbar spine BMD increased significantly at month 24 (6.1% ± 4.3%, p < 0.05 versus baseline), whereas total hip BMD and TBS did not change significantly. Changes in BTM occurred as reported previously for patients without AFF treated with teriparatide after prior bisphosphonate treatment. At month 24, fractures were healed in 6 patients, showed partial healing in 3, were unchanged in 2, and showed nonunion in 1. In a patient with two fractures, the fracture that occurred before teriparatide treatment was reported as healed, but the fracture that occurred while on treatment showed only partial healing. Bisphosphonate‐treated patients who sustain AFF show heterogeneity of bone turnover. Treatment with teriparatide resulted in increases in BTM and lumbar spine BMD, as has been reported for patients without AFF. There was no significant effect of teriparatide on hip BMD, mineralizing surface to bone surface (MS/BS), or TBS and no consistent effect on fracture healing. In the context of a patient who has experienced an AFF after receiving bisphosphonate treatment, therapy with teriparatide for 24 months would be expected to increase BMD and BTM (and probably reduce the risk of fractures resulting from osteoporosis) but should not be relied on to aid in healing of the AFF. © 2017 American Society for Bone and Mineral Research.     

Atypical subtrochanteric and diaphyseal femoral fractures: Report of a task force of the american society for bone and mineral Research

Reports linking long‐term use of bisphosphonates (BPs) with atypical fractures of the femur led the leadership of the American Society for Bone and Mineral Research (ASBMR) to appoint a task force to address key questions related to this problem. A multidisciplinary expert group reviewed pertinent published reports concerning atypical femur fractures, as well as preclinical studies that could provide insight into their pathogenesis. A case definition was developed so that subsequent studies report on the same condition. The task force defined major and minor features of complete and incomplete atypical femoral fractures and recommends that all major features, including their location in the subtrochanteric region and femoral shaft, transverse or short oblique orientation, minimal or no associated trauma, a medial spike when the fracture is complete, and absence of comminution, be present to designate a femoral fracture as atypical. Minor features include their association with cortical thickening, a periosteal reaction of the lateral cortex, prodromal pain, bilaterality, delayed healing, comorbid conditions, and concomitant drug exposures, including BPs, other antiresorptive agents, glucocorticoids, and proton pump inhibitors. Preclinical data evaluating the effects of BPs on collagen cross‐linking and maturation, accumulation of microdamage and advanced glycation end products, mineralization, remodeling, vascularity, and angiogenesis lend biologic plausibility to a potential association with long‐term BP use. Based on published and unpublished data and the widespread use of BPs, the incidence of atypical femoral fractures associated with BP therapy for osteoporosis appears to be very low, particularly compared with the number of vertebral, hip, and other fractures that are prevented by BPs. Moreover, a causal association between BPs and atypical fractures has not been established. However, recent observations suggest that the risk rises with increasing duration of exposure, and there is concern that lack of awareness and underreporting may mask the true incidence of the problem. Given the relative rarity of atypical femoral fractures, the task force recommends that specific diagnostic and procedural codes be created and that an international registry be established to facilitate studies of the clinical and genetic risk factors and optimal surgical and medical management of these fractures. Physicians and patients should be made aware of the possibility of atypical femoral fractures and of the potential for bilaterality through a change in labeling of BPs. Research directions should include development of animal models, increased surveillance, and additional epidemiologic and clinical data to establish the true incidence of and risk factors for this condition and to inform orthopedic and medical management. © 2010 American Society for Bone and Mineral Research.     

The fracture sites of atypical femoral fractures are associated with the weight-bearing lower limb alignment

PurposeAtypical femoral fractures (AFFs) are stress-related fractures that are speculated to associate with long-term treatment with bisphosphonates for osteoporosis. A history of AFF is a high risk factor for the development of a subsequent AFF in the same location of the contralateral femur, suggesting that a patient's individual anatomical factor(s) are related to the fracture site of AFFs. In this study, we investigated the radiographs of fourteen AFFs (four bilateral fractures among ten patients) treated at six hospitals associated with our university between 2005 and 2010. The fracture site and standing femorotibial angle (FTA), which reflects the mechanical axis of the lower limb, were measured on weight-bearing lower limb radiographs. The fracture site and FTA of patients with typical femoral fractures (TFF) were compared to those of patients with AFFs. The correlations were examined using Spearman's rank correlation coefficients. The fracture locations in the femora were almost the same in the patients with bilateral AFFs. There was a positive correlation between the fracture site and the standing FTA in the patients with AFFs (r = 0.82, 95% confidence interval; 0.49 to 0.94), indicating that the larger the standing FTA (varus alignment), the more distal the site of the fracture in the femur. The FTA of the patients with atypical diaphyseal femoral fracture were significantly larger compared to that of those with not only atypical subtrochanteric fractures but also TFFs. In conclusion, the fracture sites of AFFs are associated with the standing lower limb alignment, while those of TFFs are not.     

Sarcopenic Obesity and Its Temporal Associations With Changes in Bone Mineral Density,Incident Falls,and Fractures in Older Men: The Concord Health and Ageing in Men Project

Body composition and muscle function have important implications for falls and fractures in older adults. We aimed to investigate longitudinal associations between sarcopenic obesity and its components with bone mineral density (BMD) and incident falls and fractures in Australian community‐dwelling older men. A total of 1486 men aged ≥70 years from the Concord Health and Ageing in Men Project (CHAMP) study were assessed at baseline (2005–2007), 2‐year follow‐up (2007–2009; n = 1238), and 5‐year follow‐up (2010–2013; n = 861). At all three time points, measurements included appendicular lean mass (ALM), body fat percentage and total hip BMD, hand‐grip strength, and gait speed. Participants were contacted every 4 months for 6.1 ± 2.1 years to ascertain incident falls and fractures, the latter being confirmed by radiographic reports. Sarcopenic obesity was defined using sarcopenia algorithms of the European Working Group on Sarcopenia (EWGSOP) and the Foundation for the National Institutes of Health (FNIH) and total body fat ≥30% of total mass. Sarcopenic obese men did not have significantly different total hip BMD over 5 years compared with non‐sarcopenic non‐obese men (p > 0.05). EWGSOP‐defined sarcopenic obesity at baseline was associated with significantly higher 2‐year fall rates (incidence rate ratio [IRR] 1.66; 95% confidence interval [CI] 1.16–2.37), as were non‐sarcopenic obesity (1.30; 1.04–1.62) and sarcopenic non‐obesity (1.58; 1.14–2.17), compared with non‐sarcopenic non‐obese. No association with falls was found for sarcopenic obesity using the FNIH definition (1.01; 0.63–1.60), but after multivariable adjustment, the FNIH‐defined non‐sarcopenic obese group had a reduced hazard for any 6‐year fracture compared with sarcopenic obese men (hazard ratio 0.44; 95% CI 0.23–0.86). In older men, EWGSOP‐defined sarcopenic obesity is associated with increased fall rates over 2 years, and FNIH‐defined sarcopenic obese men have increased fracture risk over 6 years compared with non‐sarcopenic obese men. © 2016 American Society for Bone and Mineral Research.