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Hart DA. Towards understanding how bisphosphonate-dependent alterations to nutrient canal integrity can contribute to risk for atypical femoral fractures: Biomechanical considerations and potential relationship to a real-world analogy. Bioessays 2024; 46:e2300117. [PMID: 38059881 DOI: 10.1002/bies.202300117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 11/21/2023] [Accepted: 11/23/2023] [Indexed: 12/08/2023]
Abstract
Bisphosphonates are a class of drugs which have shown good efficacy in the treatment of post-menopausal osteoporosis, as well as a good safety profile. However, side-effects such as risk for atypical femoral fractures (AFF) have appeared, leading to a decline in use of the drugs by many patients who would benefit from the treatment. While patient characteristics have contributed to improved understanding of risk factors, the mechanisms involved that explain AFF risk have not appeared. Recently, the possibility that the mechanism(s) involved drug-induced modification of cells of the nutrient canals of the femur and subsequent compromise in the bone matrix has been published. The present Hypothesis article builds on the concept presented earlier and expands into biomechanical considerations. An analogy of the mechanisms involved to a real-life scenario is also presented. While this analogy has limitations, consideration of the biomechanical implications of progressive alterations to defects presented by compromised nutrient canal-bone matrix also presents potential relationships with AFF risk.
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Affiliation(s)
- David A Hart
- Department of Surgery, Faculty of Kinesiology, McCaig Institute for Bone, & Joint Health, University of Calgary, Calgary, Alberta, Canada
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2
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Lo JC, Yang W, Park-Sigal JJ, Ott SM. Osteoporosis and Fracture Risk among Older US Asian Adults. Curr Osteoporos Rep 2023; 21:592-608. [PMID: 37542683 PMCID: PMC10858302 DOI: 10.1007/s11914-023-00805-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/06/2023] [Indexed: 08/07/2023]
Abstract
PURPOSE OF REVIEW This review summarizes the current knowledge regarding osteoporosis and fracture among older US Asian adults. RECENT FINDINGS Asian adults have lower (areal) bone density than non-Hispanic White adults and thus are more likely to be diagnosed and treated for osteoporosis, despite their lower risk of hip fracture. The latter may relate to favorable characteristics in hip geometry, volumetric bone density, and bone microarchitecture; lower risk of falls; and other clinical factors. The fracture risk calculator FRAX accounts for the lower risk of hip fracture among US Asian adults. However, data on major osteoporotic fracture risk remain limited. Fracture rates also vary by Asian subgroup, which may have implications for fracture risk assessment. Furthermore, among women receiving bisphosphonate drugs, Asian race is a risk factor for atypical femur fracture, an uncommon complication associated with treatment duration. Recent clinical trial efficacy data pertaining to lower bisphosphonate doses and longer dosing intervals may be relevant for Asian adults. More research is needed to inform osteoporosis care of US Asian adults, including risk-benefit considerations and the optimal duration of bisphosphonate treatment. Greater evidence-based guidance for primary fracture prevention among US Asian adults will ensure health equity in the prevention of osteoporotic fractures.
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Affiliation(s)
- Joan C Lo
- Division of Research, Kaiser Permanente Northern California, 2000 Broadway, Oakland, CA, 94612, USA.
- The Permanente Medical Group, Oakland, CA, USA.
- Department of Health Systems Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, CA, USA.
| | - Wei Yang
- The Permanente Medical Group, Oakland, CA, USA
- Department of Endocrinology, Kaiser Permanente San Jose Medical Center, San Jose, CA, USA
| | - Jennifer J Park-Sigal
- The Permanente Medical Group, Oakland, CA, USA
- Department of Endocrinology, Kaiser Permanente South San Francisco Medical Center, South San Francisco, CA, USA
| | - Susan M Ott
- Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
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Xiao Y, Chen Y, Huang Y, Xiao Y. Atypical femur fracture associated with common anti-osteoporosis drugs in FDA adverse event reporting system. Sci Rep 2023; 13:10892. [PMID: 37407650 DOI: 10.1038/s41598-023-37944-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 06/30/2023] [Indexed: 07/07/2023] Open
Abstract
Atypical femur fracture (AFF) is a rare but catastrophic adverse event first reported in the long-term use of alendronate, one of the most commonly used drugs for osteoporosis currently. However, further evidence is needed to learn more regarding other common anti-osteoporosis drugs and the risk for AFF. In this study, reports of AFF were identified from Food and Drug Administration Adverse Event Reporting System database. Disproportionality analyses were performed to examine the reporting odds ratio (ROR), information component (IC) and adjusted ROR (adj. ROR) signals for AFF for common anti-osteoporosis drugs. A total of 1692 unique AFF reports were identified. The disproportionality signals (the lower bound of 95% confidence interval > 1 for ROR and adjusted ROR, and > 0 for IC) were detected for alendronate, denosumab, pamidronate, risedronate, zoledronate, ibandronate, and teriparatide while no signal was detected for raloxifene, abaloparatide, and romosozumab. When restricted in patients with osteoporosis, the disproportionality signals were still detected for alendronate, pamidronate, risedronate, denosumab, and ibandronate. Our results suggest that alendronate has the largest risk signal, while the risks varied among different bisphosphonates. In addition, denosumab was found statistically associated with AFF in both the entire database and patients with osteoporosis.
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Affiliation(s)
- Yao Xiao
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, 410008, Hunan, China
| | - Yiqian Chen
- Department of Gastroenterology, Xiangya Hospital of Central South University, Changsha, 410008, Hunan, China
| | - Yan Huang
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, 410008, Hunan, China
| | - Yuan Xiao
- Department of Endocrinology, Endocrinology Research Center, Xiangya Hospital of Central South University, Changsha, 410008, Hunan, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Changsha, 410008, Hunan, China.
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Zhou W, van Rooij JGJ, van de Laarschot DM, Zervou Z, Bruggenwirth H, Appelman‐Dijkstra NM, Ebeling PR, Demirdas S, Verkerk AJMH, Zillikens MC. Prevalence of Monogenic Bone Disorders in a Dutch Cohort of Atypical Femur Fracture Patients. J Bone Miner Res 2023; 38:896-906. [PMID: 37076969 PMCID: PMC10946469 DOI: 10.1002/jbmr.4801] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 02/12/2023] [Accepted: 03/07/2023] [Indexed: 04/21/2023]
Abstract
Atypical femur fractures (AFFs), considered rare associations of bisphosphonates, have also been reported in patients with monogenic bone disorders without bisphosphonate use. The exact association between AFFs and monogenic bone disorders remains unknown. Our aim was to determine the prevalence of monogenic bone disorders in a Dutch AFF cohort. AFF patients were recruited from two specialist bone centers in the Netherlands. Medical records of the AFF patients were reviewed for clinical features of monogenic bone disorders. Genetic variants identified by whole-exome sequencing in 37 candidate genes involved in monogenic bone disorders were classified based on the American College of Medical Genetics and Genomics (ACMG) classification guidelines. Copy number variations overlapping the candidate genes were also evaluated using DNA array genotyping data. The cohort comprises 60 AFF patients (including a pair of siblings), with 95% having received bisphosphonates. Fifteen AFF patients (25%) had clinical features of monogenic bone disorders. Eight of them (54%), including the pair of siblings, had a (likely) pathogenic variant in either PLS3, COL1A2, LRP5, or ALPL. One patient carried a likely pathogenic variant in TCIRG1 among patients not suspected of monogenic bone disorders (2%). In total, nine patients in this AFF cohort (15%) had a (likely) pathogenic variant. In one patient, we identified a 12.7 Mb deletion in chromosome 6, encompassing TENT5A. The findings indicate a strong relationship between AFFs and monogenic bone disorders, particularly osteogenesis imperfecta and hypophosphatasia, but mainly in individuals with symptoms of these disorders. The high yield of (likely) pathogenic variants in AFF patients with a clinical suspicion of these disorders stresses the importance of careful clinical evaluation of AFF patients. Although the relevance of bisphosphonate use in this relationship is currently unclear, clinicians should consider these findings in medical management of these patients. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Wei Zhou
- Department of Internal MedicineErasmus MCRotterdamThe Netherlands
| | | | | | - Zografia Zervou
- Department of Internal MedicineErasmus MCRotterdamThe Netherlands
| | | | - Natasha M Appelman‐Dijkstra
- Department of Internal Medicine, Division of EndocrinologyLeiden University Medical CenterLeidenThe Netherlands
| | - Peter R Ebeling
- Department of MedicineSchool of Clinical Sciences, Monash UniversityClaytonAustralia
| | - Serwet Demirdas
- Department of Clinical GeneticsErasmus MCRotterdamThe Netherlands
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Byun SE, Lee KJ, Shin WC, Moon NH, Kim CH. The effect of teriparatide on fracture healing after atypical femoral fracture: A systematic review and meta-analysis. Osteoporos Int 2023:10.1007/s00198-023-06768-w. [PMID: 37095179 DOI: 10.1007/s00198-023-06768-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 04/20/2023] [Indexed: 04/26/2023]
Abstract
This meta-analysis demonstrated that a greater prevalence of delayed union and nonunion and a longer time to fracture healing in the group that did not receive TPTD treatment after AFFs than in the group that received TPTD treatment. PURPOSE To date, there is no hard evidence for medical management after atypical femoral fracture (AFF), even though weak data indicate faster healing with teriparatide (TPTD). Herein, we aimed to investigate the effect of postfracture TPTD treatment on AFF healing using a pairwise meta-analysis focusing on delayed union, nonunion, and fracture healing time. METHODS A systematic search of the MEDLINE (PUBMED), Embase, and Cochrane Library databases was performed for studies investigating the effect of TPTD after AFF up to October 11, 2022. We compared the incidence of delayed union and nonunion and the time of fracture healing between the TPTD ( +) and TPTD (-) groups. RESULTS The 6 studies analyzed a total of 214 AFF patients, including 93 who received TPTD therapy after AFF and 121 who did not. The pooled analysis showed a significantly higher rate of delayed union in the TPTD (-) group than in the TPTD ( +) group (OR, 0.24; 95% CI, 0.11-0.52; P < 0.01; I2 = 0%), and a higher nonunion rate was observed in the TPTD (-) group than in the TPTD ( +) group with low heterogeneity (OR, 0.21; 95% CI, 0.06-0.78; P = 0.02; I2 = 0%). The TPTD (-) group required 1.69 months longer to achieve fracture union than the TPTD ( +) group, with statistical significance (MD = - 1.69, 95% CI: - 2.44 to - 0.95, P < 0.01; I2 = 13%). Subgroup analysis for patients with complete AFF showed that the TPTD (-) group had a higher rate of delayed union with low heterogeneity (OR, 0.22; 95% CI, 0.10-0.51; P < 0.01; I2 = 0%), but there was no significant difference in the nonunion rate between TPTD ( +) and TPTD (-) groups (OR, 0.35; 95% CI, 0.06-2.21; P = 0.25; I2 = 0%). Fracture healing took significantly longer in the TPTD (-) group (MD = - 1.81, 95% CI: - 2.55 to - 1.08; P < 0.01; I2 = 48%). The reoperation rate showed no significant difference between the two groups (OR, 0.29; 95% CI, 0.07-1.20; P = 0.09; I2 = 0%). CONCLUSIONS The current meta-analysis supported the hypothesis that TPTD treatment following AFF might benefit fracture healing, lowering the rate of delayed union and nonunion and shortening the fracture healing time.
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Affiliation(s)
- Seong-Eun Byun
- Department of Orthopedic Surgery, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea
| | - Kyung-Jae Lee
- Department of Orthopedic Surgery, Keimyung University Dongsan Medical Center, Daegu, Republic of Korea
| | - Won Chul Shin
- Department of Orthopedic Surgery, Pusan National University Yangsan Hospital, Yangsan, Republic of Korea
| | - Nam Hoon Moon
- Department of Orthopedic Surgery, Pusan National University Hospital, Pusan, Republic of Korea
| | - Chul-Ho Kim
- Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
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Hart DA. Are secondary effects of bisphosphonates on the vascular system of bone contributing to increased risk for atypical femoral fractures in osteoporosis? Bioessays 2023; 45:e2200206. [PMID: 36807308 DOI: 10.1002/bies.202200206] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/27/2023] [Accepted: 01/30/2023] [Indexed: 02/22/2023]
Abstract
Osteoporosis (OP) is a bone disease which affects a number of post-menopausal females and puts many at risk for fractures. A large number of patients are taking bisphosphonates (BPs) to treat their OP and a rare complication is the development of atypical femoral fractures (AFF). No real explanations for the mechanisms underlying the basis for development of where AFF develop while on BPs has emerged. The present hypothesis will discuss the possibility that part of the risk for an AFF is a secondary effect of BPs on a subset of vascular cells in a genetically at-risk population, leading to localized deregulation of the endothelial cell (EC)-bone cell-matrix units in nutrient channels/canals of the femur and increased risk for AFF. This concept of targeting ECs is consistent with location of AFF in the femur, the bilateral risk for occurrence of AFF, and the requirement for long term exposure to the drugs.
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Affiliation(s)
- David A Hart
- Department of Surgery, Faculty of Kinesiology, McCaig Institute for Bone & Joint Health, University of Calgary, Calgary, Alberta, Canada
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Zebaze R, Shore‐Lorenti C, Nguyen HH, Chiang C, Milat F, Ebeling PR. A Quantification Method for Disorganized Bone Components: Application to the Femoral Shaft. JBMR Plus 2023; 7:e10713. [PMID: 36751414 PMCID: PMC9893270 DOI: 10.1002/jbm4.10713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 11/12/2022] [Accepted: 11/30/2022] [Indexed: 12/23/2022] Open
Abstract
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.
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Affiliation(s)
- Roger Zebaze
- Department of MedicineSchool of Clinical Sciences, Monash UniversityClaytonVictoriaAustralia
| | - Catherine Shore‐Lorenti
- Department of MedicineSchool of Clinical Sciences, Monash UniversityClaytonVictoriaAustralia
| | - Hanh H Nguyen
- Department of MedicineSchool of Clinical Sciences, Monash UniversityClaytonVictoriaAustralia
- Department of EndocrinologyMonash HealthClaytonVictoriaAustralia
| | - Cherie Chiang
- Austin Health, Department of MedicineUniversity of MelbourneHeidelbergVictoriaAustralia
| | - Frances Milat
- Department of MedicineSchool of Clinical Sciences, Monash UniversityClaytonVictoriaAustralia
- Department of EndocrinologyMonash HealthClaytonVictoriaAustralia
- Hudson Institute of Medical ResearchClaytonVictoriaAustralia
| | - Peter R Ebeling
- Department of MedicineSchool of Clinical Sciences, Monash UniversityClaytonVictoriaAustralia
- Department of EndocrinologyMonash HealthClaytonVictoriaAustralia
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Png MA, Koh JSB, Mohan PC, Howe CY, Howe TS. Factors affecting healing and progression of conservatively treated incomplete atypical femoral fractures: retrospective observational study. J Bone Miner Metab 2023; 41:61-73. [PMID: 36371726 DOI: 10.1007/s00774-022-01378-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 10/09/2022] [Indexed: 11/14/2022]
Abstract
INTRODUCTION Incomplete atypical femoral fractures (iAFF) may occur with prolonged bisphosphonate usage. Factors influencing iAFF healing and progression are not well understood. This study of conservatively managed iAFF assessed factors influencing iAFF healing and progression including the effects of bisphosphonates and teriparatide use. MATERIALS AND METHODS Single-center retrospective observational study of 69 consecutive patients with 78 radiographically confirmed iAFF from 2002 to 2017. Serial radiographs assessed for focal cortical thickening, dreaded black line (DBL) and complete fracture. Chief outcome measures were DBL healing and complete fracture. RESULTS DBL had a significant association (p < 0.05) with fracture progression by multivariable logistic regression (55.8% versus 25.7%, odds ratio [OR] 26.57 (95% CI 1.40-504.78)) and shorter fracture-free survival (mean 3.21 versus 6.27 years). Presence of symptoms was associated with shorter fracture-free survival (mean 2.68 versus 5.98 years). Discontinuing bisphosphonates had significant associations (p < 0.001) by multivariable logistic regression with decreased fracture rate (11.6% versus 92.0%; OR 0.00, 95% CI 0.00-0.08) and longer fracture-free survival (mean 7.52 versus 1.99 years). DBL healing occurred in 36.4%, only when bisphosphonates were discontinued. Age, sex, race, fracture site, glucocorticoid use, teriparatide supplementation and duration of bisphosphonate use showed no statistically significant effect although teriparatide use appeared to improve DBL healing (50% versus 17.9%, p = 0.188). CONCLUSIONS In conservatively managed iAFF, DBL healing occurred in 36.4% if bisphosphonates were discontinued. Bisphosphonates and DBL were significantly associated with fracture progression and together with symptoms with fracture survival.
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Affiliation(s)
- Meng Ai Png
- Department of Diagnostic Radiology, Singapore General Hospital, Outram Road, Singapore, 169608, Republic of Singapore.
| | - Joyce Suang Bee Koh
- Department of Orthopedic Surgery, Singapore General Hospital, Outram Road, Singapore, 169608, Republic of Singapore
| | - P Chandra Mohan
- Department of Diagnostic Radiology, Singapore General Hospital, Outram Road, Singapore, 169608, Republic of Singapore
| | - Choong Yin Howe
- , 36 Jalan Sejarah, Singapore, 299077, Republic of Singapore
| | - Tet Sen Howe
- Department of Orthopedic Surgery, Singapore General Hospital, Outram Road, Singapore, 169608, Republic of Singapore
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Kline GA, Lix LM, Morin SN, Leslie WD. Fracture risk in Asian-Canadian women is significantly over-estimated by the Canadian Association of Radiologists-Osteoporosis Canada risk prediction tool: retrospective cohort study. Arch Osteoporos 2022; 17:133. [PMID: 36201065 DOI: 10.1007/s11657-022-01173-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 09/28/2022] [Indexed: 02/03/2023]
Abstract
Fracture risk calculators may not be accurate for all ethnicity groups. The Manitoba bone density registry was used to test the Canadian CAROC tool for predicting fracture risk in Asian-Canadian women. The tool significantly over-estimated fracture risk, suggesting that it may not be ideal for Asian-Canadian patients. PURPOSE Health risk prediction tools based on largely White populations may lead to treatment inequity when applied to non-White populations where outcome rates differ. We examined the calibration of the Canadian Association of Radiologists-Osteoporosis Canada (CAROC) fracture risk prediction tool in self-identified Asian-Canadian women. METHODS Retrospective cohort study of women over age 50 using the Manitoba BMD Registry. At first BMD, the intake questionnaire collected self-identification of ethnicity and fracture risk factors. 10-year fracture risk was estimated using CAROC and categorized into low, medium, or high fracture risk. Linked administrative databases identified incident osteoporotic fractures. Observed fracture rates were compared between White and Asian-Canadians and compared to the original CAROC risk stratification. RESULTS There were 63,632 and 1703 women who self-identified as White-Canadian or Asian-Canadian, respectively, covering approximately 600,000 patient-years follow-up. There were 6588 incident fractures; a similar percentage of patients were assigned to each risk stratum at baseline by CAROC. A progressive rise in 10-year observed fracture rates occurred for each CAROC stratum in the White-Canadian population but much lower fracture rates than predicted in Asian-Canadian patients (p < 0.001). Fracture incidence rate ratios were 1.9-2.6 fold higher in White- vs Asian-Canadian patients for all strata (p < 0.001). In the CAROC moderate and high-risk categories, observed fracture rates in Asian-Canadian patients were typically lower than predicted, indicating poor model calibration. CONCLUSION In Asian-Canadian women, observed osteoporosis fracture rates are lower than predicted when using the CAROC tool. Over-estimation of fracture risk may influence shared decision-making discussions.
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Affiliation(s)
- Gregory A Kline
- Department of Medicine, Cumming School of Medicine, University of Calgary, 1820 Richmond Rd SW, Calgary, AB, T2T 5C7, Canada.
| | - Lisa M Lix
- Department of Community Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Suzanne N Morin
- Department of Medicine, Faculty of Medicine and Health Sciences, McGill University, Montreal, Canada
| | - William D Leslie
- Departments of Internal Medicine and Radiology, Rady College of Medicine, University of Manitoba, Winnipeg, Canada
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Gani LU, Anthony NF, Dacay LM, Tan PT, Chong LR, King TFJ. Characteristics of bisphosphonate and non-bisphosphonate related atypical femoral fracture in a South East Asian population - Secondary analysis. Bone 2022; 162:116455. [PMID: 35688361 DOI: 10.1016/j.bone.2022.116455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/06/2022] [Accepted: 06/01/2022] [Indexed: 12/01/2022]
Abstract
INTRODUCTION Studies have found that not all atypical femoral fractures (AFF) are associated with bisphosphonate (BP) use. There are limited data on AFF in non-BP patients. In this study, we characterise factors associated with BP and non-BP related AFF and its mortality in a single centre in Singapore. METHODS We conducted a cohort study of subjects above 50 years old admitted to Changi General Hospital (CGH), Singapore with fragility subtrochanteric and femoral fractures from 2009 to 2015. Using the ASBMR 2014 criteria fractures are classified into atypical and typical femoral fractures. CGH uses a nationalised electronic health record that allows review of information on patient's demographics, clinical history and previous investigations. Mortality was assessed as of 31st December 2019. RESULTS Between 2009 and 2015, there were 3097 hip fractures, of which 393 were subtrochanteric and femoral fractures and 69 were classified as AFF by ASBMR 2014 criteria. 35 of AFF occurred in BP exposed and 34 occurred in non-BP exposed patients. There were no significant demographic differences in patients with BP and non-BP related AFF. There were also similar incidences of type 2 diabetes, rheumatoid arthritis and glucocorticoid use. Notably, there were a higher percentage of previous fragility fractures (35.3 % vs 9.4 %) in BP related AFF. Time to healing of fracture was slightly longer in BP related AFF at median (3 months vs 2 month, p = 0.02), however there were no differences in incidence of delayed healing. Mortality between BP and non-BP related AFF were similar. CONCLUSION In a South East Asian population in Singapore, 47.8 % of AFF were found to be non-BP related. We found no major demographic and clinical differences between BP and non-BP related AFF. Mortality between BP and non-BP related AFF was similar. Further studies are needed to better understand the optimal treatment of osteoporosis in AFF prone patients in the Asian population.
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Affiliation(s)
- L U Gani
- Department of Endocrinology, Changi General Hospital, Singapore.
| | - N F Anthony
- Department of Endocrinology, Changi General Hospital, Singapore
| | - L M Dacay
- Department of Endocrinology, Changi General Hospital, Singapore
| | - P T Tan
- Centre of Trial Research Unit, Changi General Hospital, Singapore
| | - L R Chong
- Department of Radiology, Changi General Hospital, Singapore
| | - T F J King
- Department of Endocrinology, Changi General Hospital, Singapore
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Zhou W, Nguyen HH, van de Laarschot DM, Howe TS, Koh JS, Milat F, van Rooij JG, Verlouw JA, van der Eerden BC, Stevenson M, Thakker RV, Zillikens MC, Ebeling PR. Whole Exome Sequencing in Two
Southeast
Asian Families With Atypical Femur Fractures. JBMR Plus 2022; 6:e10659. [PMID: 35991532 PMCID: PMC9382867 DOI: 10.1002/jbm4.10659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/24/2022] [Accepted: 06/06/2022] [Indexed: 11/10/2022] Open
Affiliation(s)
- Wei Zhou
- Department of Internal Medicine Erasmus Medical Center Rotterdam The Netherlands
| | - Hanh H. Nguyen
- Department of Medicine School of Clinical Sciences, Monash University Clayton VI Australia
- Department of Endocrinology Monash Health Clayton VI Australia
| | | | - Tet Sen Howe
- Department of Orthopaedic Surgery Singapore General Hospital Singapore Singapore
| | - Joyce S.B. Koh
- Department of Orthopaedic Surgery Singapore General Hospital Singapore Singapore
| | - Frances Milat
- Department of Medicine School of Clinical Sciences, Monash University Clayton VI Australia
- Department of Endocrinology Monash Health Clayton VI Australia
| | | | - Joost A.M. Verlouw
- Department of Internal Medicine Erasmus Medical Center Rotterdam The Netherlands
| | | | - Mark Stevenson
- Academic Endocrine Unit, Radcliffe Department of Medicine University of Oxford Oxford UK
| | - Rajesh V. Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine University of Oxford Oxford UK
| | - M. Carola Zillikens
- Department of Internal Medicine Erasmus Medical Center Rotterdam The Netherlands
| | - Peter R. Ebeling
- Department of Medicine School of Clinical Sciences, Monash University Clayton VI Australia
- Department of Endocrinology Monash Health Clayton VI Australia
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12
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Dhanekula ND, Crouch G, Byth K, Lau SL, Kim A, Graham E, Ellis A, Clifton‐Bligh RJ, Girgis CM. Asian Ethnicity and Femoral Geometry in Atypical Femur Fractures: Independent or inter‐dependent risk factors? JBMR Plus 2022; 6:e10607. [PMID: 35434447 PMCID: PMC9009102 DOI: 10.1002/jbm4.10607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 01/17/2022] [Accepted: 01/19/2022] [Indexed: 11/11/2022] Open
Abstract
The earliest reports of atypical femur fractures (AFF) emerged from Asia. In the West, epidemiologic studies report a greater incidence of AFFs among subjects of Asian background. Asian ethnicity is an established risk factor for AFF, but clear mechanisms to explain this risk and implications for the general development of AFF are open questions. Ethno‐specific differences in bisphosphonate action and femoral geometry have been proposed as hypotheses. In a retrospective cohort of 163 female patients presenting with AFFs or typical femur fractures (TFF), relative contributions of Asian ethnicity, proximal femoral geometry, and bisphosphonate use in AFF status were examined. There was a fourfold higher proportion of Asian subjects in the AFF compared with TFF groups (31.6%, 30/95 versus 7.4%, 5/68). Asian subjects had smaller femurs in femoral head, neck, and axial dimensions. A multiple logistic regression model for AFF status was fitted adding Asian ethnicity to three previously reported independent predictors of AFF including femoral geometry, which together comprise the Sydney AFF Score (age ≤80 years, femoral neck width <37 mm than non‐Asian, lateral cortical width at lesser trochanter ≥5 mm). Asian ethnicity was a robust independent predictor of AFF, imparting sevenfold increase in the odds of AFF after adjusting for all three variables (95% confidence interval [CI] 2.2–23.2, p = 0.001) or for overall AFF score (95% CI 2.2–22.3 p = 0.001). Overall Asian subjects had higher rates of bisphosphonate use than non‐Asian subjects (67.6% versus 47.2%, p = 0.034). Among AFF bisphosphonate users, Asian subjects had lower AFF scores than non‐Asians (Sydney AFF Score ≤1, 45.5% Asian subjects versus 22.2% non‐Asian subjects, p = 0.05). Asian ethnicity is a strong independent risk factor for AFF, unaccounted for by ethno‐specific differences in proximal femoral geometry. Bisphosphonate use may be associated with a greater predisposition for AFF in Asian subjects compared with non‐Asian subjects. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Nitesh D Dhanekula
- Faculty of Medicine and Health University of Sydney Sydney NSW Australia
- Department of Orthopaedic Surgery Westmead Hospital Westmead NSW Australia
| | - Gareth Crouch
- Faculty of Medicine and Health University of Sydney Sydney NSW Australia
| | - Karen Byth
- Faculty of Medicine and Health University of Sydney Sydney NSW Australia
- Western Sydney Local Health District (WSLHD) Research and Education Network, Westmead Hospital Westmead NSW Australia
| | - Sue Lynn Lau
- Faculty of Medicine and Health University of Sydney Sydney NSW Australia
- Department of Diabetes and Endocrinology Westmead Hospital Westmead NSW Australia
| | - Albert Kim
- Faculty of Medicine and Health University of Sydney Sydney NSW Australia
- Department of Diabetes and Endocrinology Westmead Hospital Westmead NSW Australia
- Department of Endocrinology and Diabetes Royal North Shore Hospital St Leonards NSW Australia
| | - Edward Graham
- Department of Orthopaedic Surgery Westmead Hospital Westmead NSW Australia
| | - Andrew Ellis
- Department of Orthopaedic Surgery Royal North Shore Hospital St Leonards NSW Australia
| | - Roderick J Clifton‐Bligh
- Faculty of Medicine and Health University of Sydney Sydney NSW Australia
- Department of Endocrinology and Diabetes Royal North Shore Hospital St Leonards NSW Australia
- Kolling Institute of Medical Research Sydney NSW Australia
| | - Christian M Girgis
- Faculty of Medicine and Health University of Sydney Sydney NSW Australia
- Department of Diabetes and Endocrinology Westmead Hospital Westmead NSW Australia
- Department of Endocrinology and Diabetes Royal North Shore Hospital St Leonards NSW Australia
- The Westmead Institute for Medical Research Westmead NSW Australia
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13
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Gu KD, Ettinger B, Grimsrud CD, Lo JC. Progression of atypical femur stress fracture after discontinuation of bisphosphonate therapy. Osteoporos Int 2021; 32:2119-2123. [PMID: 33914104 DOI: 10.1007/s00198-021-05948-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 04/01/2021] [Indexed: 01/16/2023]
Abstract
Atypical femur fracture (AFF) is an uncommon complication of long-term bisphosphonate use, but the risk declines substantially after treatment cessation. We report a case of a 70-year-old woman with osteopenia treated with alendronate for 9 years who presented with right mid-thigh pain and radiographic findings of focal lateral cortical thickening in the right mid-femur and lateral cortex irregularity in the proximal-mid left femur. Alendronate was discontinued, but she remained on estrogen for menopausal symptoms. Four years later, a horizontal linear translucent defect was seen in the right mid-femur area of cortical hypertrophy, consistent with an incomplete AFF. The patient underwent prophylactic intramedullary rodding of the right femur and estrogen was discontinued. Three years later (7 years after initial presentation), the cortical irregularities in the left femur were more prominent and three small horizontal linear translucent defects were now evident, consistent with early incomplete atypical fracture development. The patient also suffered a wrist fracture. She was treated with teriparatide for 1.5 years with resolution of the translucent defects in the left but not the right femur, although abnormal thickening of the lateral cortex persisted in both femurs. Our case demonstrates incomplete atypical femur fracture progression in a patient with long-term bisphosphonate exposure, even after treatment cessation. These findings highlight the importance of follow-up for patients who develop diaphyseal femur stress fractures and the potential for early healing with anabolic therapy. This case also demonstrates the challenge in managing older patients with incomplete AFF at risk for progression to complete AFF and osteoporotic fracture.
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Affiliation(s)
- K D Gu
- Department of Medicine, Kaiser Permanente Oakland Medical Center, Oakland, CA, 94611, USA
| | - B Ettinger
- Division of Research, Kaiser Permanente Northern California, 2000 Broadway, Oakland, CA, 94612, USA
| | - C D Grimsrud
- Department of Orthopedic Surgery, Kaiser Permanente Oakland Medical Center, Oakland, CA, USA
- The Permanente Medical Group, Oakland, CA, 94612, USA
| | - J C Lo
- Department of Medicine, Kaiser Permanente Oakland Medical Center, Oakland, CA, 94611, USA.
- Division of Research, Kaiser Permanente Northern California, 2000 Broadway, Oakland, CA, 94612, USA.
- The Permanente Medical Group, Oakland, CA, 94612, USA.
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14
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Griffin LV, Warner E, Palnitkar S, Qiu S, Honasoge M, Griffin SG, Divine G, Rao SD. Bone Nanomechanical Properties and Relationship to Bone Turnover and Architecture in Patients With Atypical Femur Fractures: A Prospective Nested Case-Control Study. JBMR Plus 2021; 5:e10523. [PMID: 34532612 PMCID: PMC8441274 DOI: 10.1002/jbm4.10523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/18/2021] [Accepted: 06/02/2021] [Indexed: 11/20/2022] Open
Abstract
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.
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Affiliation(s)
- Lanny V Griffin
- California Polytechnic State University (Cal Poly) San Luis Obispo CA USA
| | - Elizabeth Warner
- Bone & Mineral Research Laboratory Henry Ford Health System/Wayne State University Integrative Biosciences (IBio) Research Facility Detroit MI USA
| | - Saroj Palnitkar
- Bone & Mineral Research Laboratory Henry Ford Health System/Wayne State University Integrative Biosciences (IBio) Research Facility Detroit MI USA
| | - Shijing Qiu
- Bone & Mineral Research Laboratory Henry Ford Health System/Wayne State University Integrative Biosciences (IBio) Research Facility Detroit MI USA
| | - Mahalakshmi Honasoge
- Division of Endocrinology, Diabetes, and Bone & Mineral Disorders Henry Ford Health System Detroit MI USA
| | - Shawna G Griffin
- California Polytechnic State University (Cal Poly) San Luis Obispo CA USA
| | - George Divine
- Department of Public Health Sciences Henry Ford Health System Detroit MI USA
| | - Sudhaker D Rao
- Bone & Mineral Research Laboratory Henry Ford Health System/Wayne State University Integrative Biosciences (IBio) Research Facility Detroit MI USA.,Division of Endocrinology, Diabetes, and Bone & Mineral Disorders Henry Ford Health System Detroit MI USA
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15
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Ugartondo N, Martínez-Gil N, Esteve M, Garcia-Giralt N, Roca-Ayats N, Ovejero D, Nogués X, Díez-Pérez A, Rabionet R, Grinberg D, Balcells S. Functional Analyses of Four CYP1A1 Missense Mutations Present in Patients with Atypical Femoral Fractures. Int J Mol Sci 2021; 22:ijms22147395. [PMID: 34299011 PMCID: PMC8303772 DOI: 10.3390/ijms22147395] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/02/2021] [Accepted: 07/05/2021] [Indexed: 11/16/2022] Open
Abstract
Osteoporosis is the most common metabolic bone disorder and nitrogen-containing bisphosphonates (BP) are a first line treatment for it. Yet, atypical femoral fractures (AFF), a rare adverse effect, may appear after prolonged BP administration. Given the low incidence of AFF, an underlying genetic cause that increases the susceptibility to these fractures is suspected. Previous studies uncovered rare CYP1A1 mutations in osteoporosis patients who suffered AFF after long-term BP treatment. CYP1A1 is involved in drug metabolism and steroid catabolism, making it an interesting candidate. However, a functional validation for the AFF-associated CYP1A1 mutations was lacking. Here we tested the enzymatic activity of four such CYP1A1 variants, by transfecting them into Saos-2 cells. We also tested the effect of commonly used BPs on the enzymatic activity of the CYP1A1 forms. We demonstrated that the p.Arg98Trp and p.Arg136His CYP1A1 variants have a significant negative effect on enzymatic activity. Moreover, all the BP treatments decreased CYP1A1 activity, although no specific interaction with CYP1A1 variants was found. Our results provide functional support to the hypothesis that an additive effect between CYP1A1 heterozygous mutations p.Arg98Trp and p.Arg136His, other rare mutations and long-term BP exposure might generate susceptibility to AFF.
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Affiliation(s)
- Nerea Ugartondo
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, Universitat de Barcelona, CIBERER, IBUB, IRSJD, 08028 Barcelona, Spain; (N.U.); (N.M.-G.); (M.E.); (N.R.-A.); (R.R.)
| | - Núria Martínez-Gil
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, Universitat de Barcelona, CIBERER, IBUB, IRSJD, 08028 Barcelona, Spain; (N.U.); (N.M.-G.); (M.E.); (N.R.-A.); (R.R.)
| | - Mònica Esteve
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, Universitat de Barcelona, CIBERER, IBUB, IRSJD, 08028 Barcelona, Spain; (N.U.); (N.M.-G.); (M.E.); (N.R.-A.); (R.R.)
| | - Natàlia Garcia-Giralt
- Musculoskeletal Research Group, IMIM (Hospital del Mar Medical Research Institute), Centro de Investigación Biomédica en Red en Fragilidad y Envejecimiento Saludable (CIBERFES), ISCIII, 08003 Barcelona, Spain; (N.G.-G.); (D.O.); (X.N.); (A.D.-P.)
| | - Neus Roca-Ayats
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, Universitat de Barcelona, CIBERER, IBUB, IRSJD, 08028 Barcelona, Spain; (N.U.); (N.M.-G.); (M.E.); (N.R.-A.); (R.R.)
| | - Diana Ovejero
- Musculoskeletal Research Group, IMIM (Hospital del Mar Medical Research Institute), Centro de Investigación Biomédica en Red en Fragilidad y Envejecimiento Saludable (CIBERFES), ISCIII, 08003 Barcelona, Spain; (N.G.-G.); (D.O.); (X.N.); (A.D.-P.)
| | - Xavier Nogués
- Musculoskeletal Research Group, IMIM (Hospital del Mar Medical Research Institute), Centro de Investigación Biomédica en Red en Fragilidad y Envejecimiento Saludable (CIBERFES), ISCIII, 08003 Barcelona, Spain; (N.G.-G.); (D.O.); (X.N.); (A.D.-P.)
| | - Adolfo Díez-Pérez
- Musculoskeletal Research Group, IMIM (Hospital del Mar Medical Research Institute), Centro de Investigación Biomédica en Red en Fragilidad y Envejecimiento Saludable (CIBERFES), ISCIII, 08003 Barcelona, Spain; (N.G.-G.); (D.O.); (X.N.); (A.D.-P.)
| | - Raquel Rabionet
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, Universitat de Barcelona, CIBERER, IBUB, IRSJD, 08028 Barcelona, Spain; (N.U.); (N.M.-G.); (M.E.); (N.R.-A.); (R.R.)
| | - Daniel Grinberg
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, Universitat de Barcelona, CIBERER, IBUB, IRSJD, 08028 Barcelona, Spain; (N.U.); (N.M.-G.); (M.E.); (N.R.-A.); (R.R.)
- Correspondence: (D.G.); (S.B.); Tel.: +34-934035418 (S.B.)
| | - Susanna Balcells
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, Universitat de Barcelona, CIBERER, IBUB, IRSJD, 08028 Barcelona, Spain; (N.U.); (N.M.-G.); (M.E.); (N.R.-A.); (R.R.)
- Correspondence: (D.G.); (S.B.); Tel.: +34-934035418 (S.B.)
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16
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Gani L, Anthony N, Dacay L, Tan P, Chong LR, King TF. Incidence of Atypical Femoral Fracture and Its Mortality in a Single Center in Singapore. JBMR Plus 2021; 5:e10515. [PMID: 34368607 PMCID: PMC8328799 DOI: 10.1002/jbm4.10515] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 04/30/2021] [Accepted: 05/13/2021] [Indexed: 12/29/2022] Open
Abstract
Bisphosphonates (BP) are the most commonly prescribed effective form of osteoporosis treatment with adverse effects associated with prolonged use such as atypical femoral fractures (AFF). Asians have an elevated risk of AFF at 5 to 6 times those of whites and Hispanics. In this study, we characterize factors associated with AFF and its mortality in a single center in Singapore. We conducted a cohort study of subjects older than 50 years admitted to Changi General Hospital (CGH), Singapore, with fragility subtrochanteric femoral fractures from 2009 to 2015. Using the ASBMR 2014 criteria, fractures are classified into atypical and typical subtrochanteric femoral fractures. CGH uses a nationalized electronic health record that allows review of information on patients' demographics, clinical history and previous investigations. Mortality was assessed as of December 31, 2019. Between 2009 and 2015, there were 3097 hip fractures, of which 393 were subtrochanteric femoral fractures and 69 were classified as AFF by ASBMR 2014 criteria. A total of 52.2% of AFF occurred with BP exposure of median duration 56.5 (28 to 66) months. Multivariate regression showed that BP exposure was associated with the highest risk of AFF (odds ratio [OR] = 6.65 [2.35–18.9]). AFF patients had higher 5‐year survival (0.85 versus 0.62, p = 0.001) compared with typical subtrochanteric fracture patients. However, after adjusting for variables, the type of subtrochanteric femoral fractures were no longer significantly associated with progression to death, whereas older age, higher mean Charlson comorbidity score, and Malay ethnicity were the strongest predictors of death. AFF constitutes a small proportion of hip and femoral fractures with prolonged BP use being the highest risk factor for its development. There is no evidence of increased mortality or morbidity in patients with AFF compared with the typical subtrochanteric fracture. The fear of AFF should not impede treatment of typical osteoporotic fractures in this population. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Linsey Gani
- Department of Endocrinology Department of Medicine Changi General Hospital 2 Simei Street 3 529889 Singapore Singapore
| | - Natasha Anthony
- Department of Endocrinology Department of Medicine Changi General Hospital 2 Simei Street 3 529889 Singapore Singapore
| | - Lily Dacay
- Department of Endocrinology Department of Medicine Changi General Hospital 2 Simei Street 3 529889 Singapore Singapore
| | - Pei Tan
- Centre of Trial Research Unit Changi General Hospital Singapore Singapore
| | - Le Roy Chong
- Department of Radiology Changi General Hospital Singapore Singapore
| | - Thomas Fj King
- Department of Endocrinology Department of Medicine Changi General Hospital 2 Simei Street 3 529889 Singapore Singapore
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17
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Crouch G, Dhanekula ND, Byth K, Burn E, Lau SL, Nairn L, Nery L, Doyle J, Graham E, Ellis A, Clifton-Bligh RJ, Girgis CM. The Sydney AFF Score: A Simple Tool to Distinguish Females Presenting With Atypical Femur Fractures Versus Typical Femur Fractures. J Bone Miner Res 2021; 36:910-920. [PMID: 33528853 DOI: 10.1002/jbmr.4255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 01/05/2021] [Accepted: 01/12/2021] [Indexed: 01/21/2023]
Abstract
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).
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Affiliation(s)
- Gareth Crouch
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Nitesh D Dhanekula
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia.,Department of Orthopaedic Surgery, Westmead Hospital, Westmead, NSW, Australia
| | - Karen Byth
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia.,Western Sydney Local Health District (WSLHD) Research and Education Network, Westmead Hospital, Westmead, NSW, Australia
| | - Emma Burn
- Department of Medicine, West Suffolk Hospital, Bury St Edmonds, UK
| | - Sue Lynn Lau
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia.,Department of Endocrinology and Diabetes, Westmead Hospital, Westmead, NSW, Australia
| | - Lillias Nairn
- Department of Physiotherapy, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - Liza Nery
- Department of Endocrinology and Diabetes, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - Jean Doyle
- Department of Endocrinology and Diabetes, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - Edward Graham
- Department of Orthopaedic Surgery, Westmead Hospital, Westmead, NSW, Australia
| | - Andrew Ellis
- Department of Orthopaedic Surgery, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - Roderick J Clifton-Bligh
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia.,Department of Endocrinology and Diabetes, Royal North Shore Hospital, St Leonards, NSW, Australia.,Kolling Institute of Medical Research, Sydney, NSW, Australia
| | - Christian M Girgis
- Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia.,Department of Endocrinology and Diabetes, Westmead Hospital, Westmead, NSW, Australia.,Department of Endocrinology and Diabetes, Royal North Shore Hospital, St Leonards, NSW, Australia.,The Westmead Institute for Medical Research, Westmead, NSW, Australia
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18
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Zhou W, van Rooij JGJ, Ebeling PR, Verkerk AJMH, Zillikens MC. The Genetics of Atypical Femur Fractures-a Systematic Review. Curr Osteoporos Rep 2021; 19:123-130. [PMID: 33587247 PMCID: PMC8016774 DOI: 10.1007/s11914-021-00658-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/19/2021] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW Atypical femur fractures (AFFs) are rare subtrochanteric or diaphyseal fractures regarded as side effects of bisphosphonates (BPs), possibly with a genetic background. Here, we summarize the most recent knowledge about genetics of AFFs. RECENT FINDINGS AFF has been reported in 57 patients with seven different monogenic bone disorders including hypophosphatasia and osteogenesis imperfecta; 56.1% had never used BPs, while 17.5% were diagnosed with the disorder only after the AFF. Gene mutation finding in familial and sporadic cases identified possible AFF-related variants in the GGPS1 and ATRAID genes respectively. Functional follow-up studies of mutant proteins showed possible roles in AFF. A recent small genome-wide association study on 51 AFF cases did not identify significant hits associated with AFF. Recent findings have strengthened the hypothesis that AFFs have underlying genetic components but more studies are needed in AFF families and larger cohorts of sporadic cases to confirm previous results and/or find novel gene variants involved in the pathogenesis of AFFs.
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Affiliation(s)
- Wei Zhou
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Jeroen G J van Rooij
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
- Department of Neurology & Alzheimer Center, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Peter R Ebeling
- Department of Medicine, School of Clinical Sciences, Monash University, Clayton, Australia
| | - Annemieke J M H Verkerk
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - M Carola Zillikens
- Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands.
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19
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Black DM, Geiger EJ, Eastell R, Vittinghoff E, Li BH, Ryan DS, Dell RM, Adams AL. Atypical Femur Fracture Risk versus Fragility Fracture Prevention with Bisphosphonates. N Engl J Med 2020; 383:743-753. [PMID: 32813950 PMCID: PMC9632334 DOI: 10.1056/nejmoa1916525] [Citation(s) in RCA: 173] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Bisphosphonates are effective in reducing hip and osteoporotic fractures. However, concerns about atypical femur fractures have contributed to substantially decreased bisphosphonate use, and the incidence of hip fractures may be increasing. Important uncertainties remain regarding the association between atypical femur fractures and bisphosphonates and other risk factors. METHODS We studied women 50 years of age or older who were receiving bisphosphonates and who were enrolled in the Kaiser Permanente Southern California health care system; women were followed from January 1, 2007, to November 30, 2017. The primary outcome was atypical femur fracture. Data on risk factors, including bisphosphonate use, were obtained from electronic health records. Fractures were radiographically adjudicated. Multivariable Cox models were used. The risk-benefit profile was modeled for 1 to 10 years of bisphosphonate use to compare associated atypical fractures with other fractures prevented. RESULTS Among 196,129 women, 277 atypical femur fractures occurred. After multivariable adjustment, the risk of atypical fracture increased with longer duration of bisphosphonate use: the hazard ratio as compared with less than 3 months increased from 8.86 (95% confidence interval [CI], 2.79 to 28.20) for 3 years to less than 5 years to 43.51 (95% CI, 13.70 to 138.15) for 8 years or more. Other risk factors included race (hazard ratio for Asians vs. Whites, 4.84; 95% CI, 3.57 to 6.56), height, weight, and glucocorticoid use. Bisphosphonate discontinuation was associated with a rapid decrease in the risk of atypical fracture. Decreases in the risk of osteoporotic and hip fractures during 1 to 10 years of bisphosphonate use far outweighed the increased risk of atypical fracture among Whites but less so among Asians. After 3 years, 149 hip fractures were prevented and 2 bisphosphonate-associated atypical fractures occurred in Whites, as compared with 91 and 8, respectively, in Asians. CONCLUSIONS The risk of atypical femur fracture increased with longer duration of bisphosphonate use and rapidly decreased after bisphosphonate discontinuation. Asians had a higher risk than Whites. The absolute risk of atypical femur fracture remained very low as compared with reductions in the risk of hip and other fractures with bisphosphonate treatment. (Funded by Kaiser Permanente and others.).
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Affiliation(s)
- Dennis M Black
- From the Departments of Epidemiology and Biostatistics (D.M.B., E.V.) and Orthopedic Surgery (E.J.G.), University of California, San Francisco, San Francisco, the Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena (D.M.B., B.H.L., D.S.R., A.L.A.), and the Department of Orthopedics, Kaiser Permanente Southern California, Downey (R.M.D.) - all in California; and the Department of Oncology and Metabolism, University of Sheffield, Sheffield, United Kingdom (R.E.)
| | - Erik J Geiger
- From the Departments of Epidemiology and Biostatistics (D.M.B., E.V.) and Orthopedic Surgery (E.J.G.), University of California, San Francisco, San Francisco, the Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena (D.M.B., B.H.L., D.S.R., A.L.A.), and the Department of Orthopedics, Kaiser Permanente Southern California, Downey (R.M.D.) - all in California; and the Department of Oncology and Metabolism, University of Sheffield, Sheffield, United Kingdom (R.E.)
| | - Richard Eastell
- From the Departments of Epidemiology and Biostatistics (D.M.B., E.V.) and Orthopedic Surgery (E.J.G.), University of California, San Francisco, San Francisco, the Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena (D.M.B., B.H.L., D.S.R., A.L.A.), and the Department of Orthopedics, Kaiser Permanente Southern California, Downey (R.M.D.) - all in California; and the Department of Oncology and Metabolism, University of Sheffield, Sheffield, United Kingdom (R.E.)
| | - Eric Vittinghoff
- From the Departments of Epidemiology and Biostatistics (D.M.B., E.V.) and Orthopedic Surgery (E.J.G.), University of California, San Francisco, San Francisco, the Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena (D.M.B., B.H.L., D.S.R., A.L.A.), and the Department of Orthopedics, Kaiser Permanente Southern California, Downey (R.M.D.) - all in California; and the Department of Oncology and Metabolism, University of Sheffield, Sheffield, United Kingdom (R.E.)
| | - Bonnie H Li
- From the Departments of Epidemiology and Biostatistics (D.M.B., E.V.) and Orthopedic Surgery (E.J.G.), University of California, San Francisco, San Francisco, the Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena (D.M.B., B.H.L., D.S.R., A.L.A.), and the Department of Orthopedics, Kaiser Permanente Southern California, Downey (R.M.D.) - all in California; and the Department of Oncology and Metabolism, University of Sheffield, Sheffield, United Kingdom (R.E.)
| | - Denison S Ryan
- From the Departments of Epidemiology and Biostatistics (D.M.B., E.V.) and Orthopedic Surgery (E.J.G.), University of California, San Francisco, San Francisco, the Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena (D.M.B., B.H.L., D.S.R., A.L.A.), and the Department of Orthopedics, Kaiser Permanente Southern California, Downey (R.M.D.) - all in California; and the Department of Oncology and Metabolism, University of Sheffield, Sheffield, United Kingdom (R.E.)
| | - Richard M Dell
- From the Departments of Epidemiology and Biostatistics (D.M.B., E.V.) and Orthopedic Surgery (E.J.G.), University of California, San Francisco, San Francisco, the Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena (D.M.B., B.H.L., D.S.R., A.L.A.), and the Department of Orthopedics, Kaiser Permanente Southern California, Downey (R.M.D.) - all in California; and the Department of Oncology and Metabolism, University of Sheffield, Sheffield, United Kingdom (R.E.)
| | - Annette L Adams
- From the Departments of Epidemiology and Biostatistics (D.M.B., E.V.) and Orthopedic Surgery (E.J.G.), University of California, San Francisco, San Francisco, the Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena (D.M.B., B.H.L., D.S.R., A.L.A.), and the Department of Orthopedics, Kaiser Permanente Southern California, Downey (R.M.D.) - all in California; and the Department of Oncology and Metabolism, University of Sheffield, Sheffield, United Kingdom (R.E.)
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