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Falotico GG, Cunza JFF, Ferreira GF, Oliveira VO, Oksman D, Arliani GG. Fraturas atípicas do fêmur associadas ao uso crônico de bisfosfonatos: Uma série de casos de 66 pacientes. Rev Bras Ortop 2021; 57:851-855. [PMID: 36226208 PMCID: PMC9550375 DOI: 10.1055/s-0041-1726066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 12/01/2020] [Indexed: 10/28/2022] Open
Abstract
Resumo
Objetivo Descrever os resultados de uma série de pacientes tratados cirurgicamente com diagnóstico de fratura femoral atípica associada ao uso de bisfosfonatos, assim como correlacionar o tempo de uso prévio da medicação com o tempo de consolidação da fratura e comparar o tempo de consolidação das fraturas completas e incompletas.
Métodos Trata-se de um estudo observacional e retrospectivo de 66 pacientes com diagnóstico de fratura atípica do fêmur associada ao uso crônico de bisfosfonatos. Os pacientes foram submetidos ao tratamento cirúrgico ortopédico em hospital de referência no período de janeiro de 2018 a março de 2020.
Resultados Os pacientes incluídos no estudo eram todos do sexo feminino, com dois casos bilaterais. A consolidação da fratura ocorreu em todos os casos com tempo médio de 2,3 meses e seguimento de 5,8 meses. O tempo médio de uso de bisfosfonatos foi de 7,8 anos. Não houve correlação do tempo de uso prévio de bisfosfonatos com o tempo de consolidação das fraturas. Houve uma diferença do tempo de consolidação entre as fraturas completas e incompletas.
Conclusão Houve consolidação após tratamento cirúrgico com haste cefalomedular longa em todos os pacientes do presente estudo, sendo o tempo de consolidação maior nas fraturas completas em relação às incompletas, e não houve correlação entre o tempo de uso prévio de bisfosfonatos e o tempo de consolidação.
Nível de evidência Nível IV, série de casos
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Affiliation(s)
| | | | | | - Victor Otávio Oliveira
- Departamento de Ortopedia e Traumatologia, Instituto Prevent Senior, São Paulo, SP, Brasil
| | - Daniel Oksman
- Departamento de Ortopedia e Traumatologia, Instituto Prevent Senior, São Paulo, SP, Brasil
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Tsuchie H, Miyakoshi N, Kasukawa Y, Nozaka K, Saito K, Kinoshita H, Kobayashi M, Suzuki N, Aizawa T, Abe H, Maekawa S, Tomite T, Ono Y, Ouchi K, Shibata N, Nagahata I, Takeshima M, Akagawa M, Yuasa Y, Sato C, Shimada Y. Evaluation of the Nature and Etiologies of Risk Factors for Diaphyseal Atypical Femoral Fractures. Med Princ Pract 2021; 30:430-436. [PMID: 34058735 PMCID: PMC8562049 DOI: 10.1159/000517484] [Citation(s) in RCA: 3] [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: 12/07/2020] [Accepted: 05/26/2021] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Differences in mechanisms of subtrochanteric and diaphyseal atypical femoral fractures (AFFs) are speculated in studies that analyzed differences in the patients' background. However, the etiologies of each type of AFF have not been studied in detail. This study aimed to investigate the nature and etiologies of the risk factors for diaphyseal AFFs. MATERIALS AND METHODS Eighty consecutive Japanese patients with 91 diaphyseal AFFs (AFF group) and 110 age-matched women with osteoporosis (non-AFF control group) were included. Their clinical data were compared; factors affecting AFFs were investigated, and the etiologies of the risk factors for diaphyseal AFFs were examined. RESULTS Multivariate analysis revealed that femoral serrated changes, bisphosphonate or denosumab usage, and lateral and anterior femoral curvatures were risk factors for diaphyseal AFFs (p < 0.0011, p = 0.0137, and p < 0.0001, respectively). Multivariate analyses revealed that serrated changes and low serum 25(OH)D levels affected the lateral curvature (p = 0.0088 and 0.0205, respectively), while serrated changes affected the anterior curvature (p = 0.0006), each significantly affected the femoral curvature. High serum calcium (Ca) levels, lateral femoral curvature, and anterior femoral curvature were predictors of serrated changes (p = 0.0146, 0.0002, and 0.0098, respectively). CONCLUSION Risk factors for diaphyseal AFFs were bone resorption inhibitor usage, a strong femoral curvature, and serrated changes. Low serum 25(OH)D levels and serrated changes are risk factors for lateral curvature, while a high serum Ca level is a risk factor for serrated changes.
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Affiliation(s)
- Hiroyuki Tsuchie
- Department of Orthopedic Surgery, Akita University Graduate School of Medicine, Akita, Japan
- *Hiroyuki Tsuchie, .jp
| | - Naohisa Miyakoshi
- Department of Orthopedic Surgery, Akita University Graduate School of Medicine, Akita, Japan
| | - Yuji Kasukawa
- Department of Orthopedic Surgery, Akita University Graduate School of Medicine, Akita, Japan
| | - Koji Nozaka
- Department of Orthopedic Surgery, Akita University Graduate School of Medicine, Akita, Japan
| | - Kimio Saito
- Department of Orthopedic Surgery, Akita University Graduate School of Medicine, Akita, Japan
- Department of Orthopedic Surgery, Kakunodate General Hospital, Senboku, Japan
| | - Hayato Kinoshita
- Department of Orthopedic Surgery, Akita Kousei Medical Center, Akita, Japan
| | - Moto Kobayashi
- Department of Orthopedic Surgery, Hiraka General Hospital, Yokote, Japan
| | - Norio Suzuki
- Department of Orthopedic Surgery, Yuri Kumiai General Hospital, Yurihonjyo, Japan
| | - Toshiaki Aizawa
- Department of Orthopedic Surgery, Northern Akita Municipal Hospital, Kitaakita, Japan
| | - Hidekazu Abe
- Department of Orthopedic Surgery, Ugo Municipal Hospital, Ugo, Japan
| | - Shigeto Maekawa
- Department of Orthopedic Surgery, Ogachi Central Hospital, Yuzawa, Japan
| | - Takenori Tomite
- Department of Orthopedic Surgery, Japanese Red Cross Akita Hospital, Akita, Japan
| | - Yuichi Ono
- Department of Orthopedic Surgery, Nakadori General Hospital, Akita, Japan
| | - Kentaro Ouchi
- Department of Orthopedic Surgery, Yokote Municipal Hospital, Yokote, Japan
| | - Nobusuke Shibata
- Department of Orthopedic Surgery, Oga Minato Municipal Hospital, Oga, Japan
| | - Itsuki Nagahata
- Department of Orthopedic Surgery, Omagari Kousei Medical Center, Daisen, Japan
| | - Masaaki Takeshima
- Department of Orthopedic Surgery, Honjyo Daiichi Hospital, Yurihonjyo, Japan
| | - Manabu Akagawa
- Department of Orthopedic Surgery, Akita City Hospital, Akita, Japan
| | - Yusuke Yuasa
- Department of Orthopedic Surgery, Omori Municipal Hospital, Yokote, Japan
| | - Chie Sato
- Department of Orthopedic Surgery, Akita Rosai Hospital, Odate, Japan
| | - Yoichi Shimada
- Department of Orthopedic Surgery, Akita University Graduate School of Medicine, Akita, Japan
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Won SH, Ahn S, Ji E, Park JW, Kim JK, Lee YK. Hip and Subtrochanteric or Femoral Shaft Fractures after Bisphosphonate Use in Korean Women, Using Korean National Sample Cohort. J Korean Med Sci 2020; 35:e193. [PMID: 32597040 PMCID: PMC7324261 DOI: 10.3346/jkms.2020.35.e193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 04/27/2020] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Concern about bisphosphonate-associated subtrochanteric and femoral shaft (ST/FS) fractures has been raised. However, its real risk is still debatable, because there is no study to estimate risk and benefit of bisphosphonate. The objective of this study was to evaluate the risk of typical hip fractures and ST/FS fractures among bisphosphonate users using nationwide database. METHODS We performed a retrospective cohort study using National Health Insurance Service-National Sample Cohort. We evaluated occurrence of the ST/FS and femoral neck and intertrochanteric (FN/IT) fractures among female bisphosphonate new users. Incidence rate of ST/FS and FN/IT fractures were compared between long-term users (≥ 1 year) and short-term users (< 1 year). Number needed to harm (NNH) for ST/FS and number needed to treat (NNT) for typical hip fracture were analyzed. RESULTS Among 46,420 bisphosphonate users, we identified 14,689 long-term users and 21,840 short-term users. During the study period, 61 long-term users and 36 short-term users had ST/FS fractures, while 204 long-term users and 511 short-term users had FN/IT fractures. The long-term user showed higher incidence rate of ST/FS fractures (67.1/100,000 person-years; 95% confidence interval [CI], 50.3-83.9) comparing with 31.2/100,000 person-years (95% CI, 21.0-41.4) in the short-term users. The incidence rate of FN/IT fractures was 225.5/100,000 person-years (95% CI, 194.6-256.5) in the long-term users and 448.6/100,000 person-years (95% CI, 409.7-487.5) in the short-term users. The NNH for ST/FS was 400, while the NNT for typical hip fracture was 105. CONCLUSION Our study suggested that physicians keep the significant benefit of bisphosphonate to prevent typical hip fracture in mind, even the concerns about bisphosphonate-associated ST/FS fractures.
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Affiliation(s)
- Seok Hyung Won
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Soyeon Ahn
- Division of Statistics, Medical Research Collaborating Center, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Eunjeong Ji
- Division of Statistics, Medical Research Collaborating Center, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Jung Wee Park
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Jin Kak Kim
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Young Kyun Lee
- Department of Orthopedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.
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Atypical femoral fractures from bisphosphonate in cancer patients - Review. J Bone Oncol 2019; 18:100259. [PMID: 31497503 PMCID: PMC6722257 DOI: 10.1016/j.jbo.2019.100259] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 08/13/2019] [Accepted: 08/21/2019] [Indexed: 02/08/2023] Open
Abstract
Bisphosphonates are commonly used in patients with metastatic bone disease to prevent skeletal related events. Atypical femur fracture is a known complication of long-term bisphosphonate use but the incidence in cancer patients and pathogenesis are not well known. Several mechanisms of pathogenesis have been proposed including altered angiogenesis, altered bone mechanical properties, micro damage and bone remodeling suppression. Atypical femur fractures are atraumatic or minimally traumatic fractures in the sub trochanteric region or the femoral shaft. Awareness of atypical femur fractures is critical to diagnose and treat them in a timely manner. There is a paucity of data regarding the management of atypical femur fracture in patients with malignancy. Management options of atypical femur fractures include stopping bisphosphonates, initiating calcium/vitamin D supplementation and either surgery with internal fixation or conservative management. In the future, it will be important to explore the effect of continuous vs. intermittent exposure, cumulative dose and length of exposure on the incidence of this complication. Herein, we review the epidemiology, risk factors, management options and proposed mechanisms of pathogenesis of atypical femur fractures.
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Key Words
- AFF, atypical femur fracture
- AGE, advanced glycation end products
- ASBMR, American Society of Bone and Mineral Research
- Atypical femur fracture
- BP, bisphosphonate
- Bisphosphonates
- Bone metastasis
- Bone remodeling
- CI, confidence interval
- CT, computed tomography
- Denosumab
- GGPPS, geranyl geranyl pyrophosphate synthase Her2, human epidermal growth factor receptor
- IM, intramedullary
- IV, intravenous
- MGUS, monoclonal gammopathy of unknown significance
- MRI, magnetic resonance imaging
- ONJ, osteonecrosis of the jaw
- OR, odds ratio
- ORIF, open reduction internal fixation
- RCT, randomized clinical trial
- VEGF, vascular endothelial growth factor
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Affiliation(s)
- Abdel R Elniel
- Academic Department of Trauma and Orthopaedics, Leeds Teaching Hospitals, School of Medicine, University of Leeds, Leeds, United Kingdom
| | - Peter V Giannoudis
- Academic Department of Trauma and Orthopaedics, Leeds Teaching Hospitals, School of Medicine, University of Leeds, Leeds, United Kingdom; NIHR Leeds Biomedical Research Center, Chapel Allerton Hospital, Leeds, UK.
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Abstract
PURPOSE OF REVIEW To summarize reports published since the 2013 American Society of Bone and Mineral Research Task Force Report on atypical femoral fractures (AFF). RECENT FINDINGS The absolute incidence of AFFs remains low. AFFs are primarily associated with prolonged bisphosphonate (BP) exposure, but have also been reported in unexposed patients and those receiving denosumab for osteoporosis and metastatic bone disease. Asians may be more susceptible to AFFs. Lateral femoral bowing and varus hip geometry, which increase loading forces on the lateral femoral cortex, may increase AFF risk. Altered bone material properties associated with BP therapy may predispose to AFFs by permitting initiation and increasing propagation of micro-cracks. Relevant genetic mutations have been reported in patients with AFFs. Single X-ray absorptiometry femur scans permit early detection of incomplete and/or asymptomatic AFFs. Orthopedists recommend intramedullary rods for complete AFFs and for incomplete, radiologically advanced AFFs associated with pain and/or marrow edema on MRI. Teriparatide may advance AFF healing but few data support its efficacy. Greater understanding of biological and genetic predisposition to AFF may allow characterization of individual risk prior to initiating osteoporosis therapy and help allay fear in those at low risk for this complication, which remains rare in comparison to the osteoporotic fractures prevented by antiresorptive therapy.
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Affiliation(s)
- Jessica Starr
- Division of Endocrinology, Department of Medicine, Columbia University Irving Medical Center, 180 Fort Washington Avenue, Room 9-910, New York, NY, 10032, USA
| | | | - Elizabeth Shane
- Division of Endocrinology, Department of Medicine, Columbia University Irving Medical Center, 180 Fort Washington Avenue, Room 9-910, New York, NY, 10032, USA.
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Dell R, Greene D. A proposal for an atypical femur fracture treatment and prevention clinical practice guideline. Osteoporos Int 2018; 29:1277-1283. [PMID: 29675745 DOI: 10.1007/s00198-018-4506-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 03/23/2018] [Indexed: 01/27/2023]
Abstract
UNLABELLED The prevention as well as the treatment of atypical femur fractures (AFFs) remains controversial but there have been many clinical recommendations suggested. We have summarized these recommendations as well as expanded upon them in this paper. INTRODUCTION The purpose of the paper was to develop a clinical practice guideline that both treats AFF and decreases the risk of AFF in patients requiring antiresorptive medications. Examples of these medications include bisphosphonates and denosumab for the treatment of osteoporosis. METHODS A literature review looking for recommendations on AFF identification, management, and prevention was done. We also performed an updated review of clinical guidelines on AFF prevention and treatment that were developed for the Kaiser Permanente osteoporosis/fracture prevention team. RESULTS Concise clinical practice guidelines are presented that can be applied in treatment of AFF as well as help reduce the risk of developing an AFF in patients requiring antiresorptive medications. These guidelines are based on using both typical fracture and AFF risk assessment to determine duration of antiresorptive of 3 to 5 years before consideration if a drug holiday is needed. Specific groups such as younger Asian women should be reassessed at 3 years with DXA and FRAX to see if a drug holiday is needed whereas patients at higher risk for typical fractures may be reassessed at 5 years of treatment. The DXA rescreening can now be accessed if focal or generalized lateral cortex changes are present that may indicate incomplete AFFs are present. If an incomplete AFF is discovered either by DXA or by other imaging studies, it is imperative to stop antiresorptive medications and to take additional measures to lower the risk of progression to a complete AFF. If complete AFF does occur, then antiresorptive medications should be stopped and additional measures should be taken to decrease the risk of developing an AFF on the contralateral femur. CONCLUSIONS Clinical practice guidelines for the treatment and prevention of AFF will benefit clinicians who are frequently faced with having to make clinical decisions in patients requiring antiresorptive medications.
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Affiliation(s)
- R Dell
- Kaiser Downey Southern California, 9353 Imperial Hwy, Downey, CA, 90242, USA.
| | - D Greene
- Kaiser Downey Southern California, 9353 Imperial Hwy, Downey, CA, 90242, USA
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Haider IT, Schneider P, Michalski A, Edwards WB. Influence of geometry on proximal femoral shaft strains: Implications for atypical femoral fracture. Bone 2018; 110:295-303. [PMID: 29482067 DOI: 10.1016/j.bone.2018.02.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 01/25/2018] [Accepted: 02/17/2018] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Atypical femoral fractures (AFF) are characterized as low-energy fractures of the femoral shaft or subtrochanteric region. Femoral geometry is known to play a role in AFF risk; it is hypothesized that high-risk geometries are associated with elevated femoral shaft strain. However, it is not well known which geometric parameters have the greatest effect on strain, or whether interaction between parameters is significant. The purpose of this study was to thoroughly quantify the relationship between femoral geometry and diaphyseal strain, using patient specific finite element (FE) modelling in concert with parametric mesh morphing. METHODS Ten FE models were generated from computed tomography (CT) images of cadaveric femora. Heterogeneous material properties were assigned based on average CT intensities at element locations and models were subject to loads and boundary conditions representing the stance phase of gait. Mesh morphing was used to manipulate 8 geometric parameters: neck shaft angle (NSA), neck version angle (NV), neck length (NL), femoral length (FL), lateral bowing angle (L.Bow), anterior bowing angle (A.Bow), shaft diameter (S.Dia), and cortical bone thickness (C·Th). A 2-Level full factorial analysis was used to explore the effect of different combinations of physiologically realistic minimum and maximum values for each parameter. Statistical analysis (Generalized Estimating Equations) was used to assess main effects and first order interactions of each parameter. RESULTS Six independent parameters and seven interaction terms had statistically significant (p<0.05) effects on peak strain and strained volume. For both measures, the greatest changes were caused by S.Dia, L.Bow, and A.Bow, and/or first order interactions involving two of these variables. CONCLUSIONS As hypothesized, a large number of geometric measures (six) and first order interactions (seven) are associated with changes in femoral shaft strain. These measures can be evaluated radiographically, which may have important implications for future studies investigating AFF risk in clinical populations.
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Affiliation(s)
- Ifaz T Haider
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Dr. NW, Calgary, Alberta T2N 1N4, Canada; McCaig Institute for Bone and Joint Health, University of Calgary, HRIC 3A08, 3280 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada.
| | - Prism Schneider
- McCaig Institute for Bone and Joint Health, University of Calgary, HRIC 3A08, 3280 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada; Department of Surgery, Department of Community Health Sciences, Cumming School of Medicine, Foothills Campus, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
| | - Andrew Michalski
- McCaig Institute for Bone and Joint Health, University of Calgary, HRIC 3A08, 3280 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada; Biomedical Engineering Graduate Program, University of Calgary, 2500 University Dr. NW, Calgary, Alberta T2N 1N4, Canada
| | - W Brent Edwards
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, 2500 University Dr. NW, Calgary, Alberta T2N 1N4, Canada; McCaig Institute for Bone and Joint Health, University of Calgary, HRIC 3A08, 3280 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada; Biomedical Engineering Graduate Program, University of Calgary, 2500 University Dr. NW, Calgary, Alberta T2N 1N4, Canada
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Adler RA. MANAGEMENT OF ENDOCRINE DISEASE: Atypical femoral fractures: risks and benefits of long-term treatment of osteoporosis with anti-resorptive therapy. Eur J Endocrinol 2018; 178:R81-R87. [PMID: 29339529 DOI: 10.1530/eje-17-1002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 01/16/2018] [Indexed: 01/04/2023]
Abstract
Modern osteoporosis treatment began in the mid-1990s with the approval of amino-bisphosphonates, anti-resorptive agents that have been shown to decrease osteoporotic fracture risk by about half. In 2005, the first cases of atypical femoral fractures (AFF), occurring in the shaft of the femur, were reported. Since then, more cases have been found, leading to great concern among patients and a dramatic decrease in bisphosphonate prescribing. The pathogenesis and incidence of AFF are reviewed herein. Management and an approach to prevention or early detection of AFF are also provided. Denosumab, a more recently approved anti-resorptive medication has also been associated with AFF. Long-term management of osteoporosis and prevention of fracture are challenging in light of this serious but uncommon side effect, yet with an aging population osteoporotic fracture is destined to increase in frequency.
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Affiliation(s)
- Robert A Adler
- Endocrinology and Metabolism Section, McGuire Veterans Affairs Medical Center, Division of Endocrinology,Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
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Oh Y, Fujita K, Wakabayashi Y, Kurosa Y, Okawa A. Location of atypical femoral fracture can be determined by tensile stress distribution influenced by femoral bowing and neck-shaft angle: a CT-based nonlinear finite element analysis model for the assessment of femoral shaft loading stress. Injury 2017; 48:2736-2743. [PMID: 28982480 DOI: 10.1016/j.injury.2017.09.023] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 09/25/2017] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Loading stress due to individual variations in femoral morphology is thought to be strongly associated with the pathogenesis of atypical femoral fracture (AFF). In Japan, studies on AFF regarding pathogenesis in the mid-shaft are well-documented and a key factor in the injury is thought to be femoral shaft bowing deformity. Thus, we developed a CT-based finite element analysis (CT/FEA) model to assess distribution of loading stress in the femoral shaft. PATIENTS AND METHODS A multicenter prospective study was performed at 12 hospitals in Japan from August 2015 to February 2017. We assembled three study groups-the mid-shaft AFF group (n=12), the subtrochanteric AFF group (n=10), and the control group (n=11)-and analyzed femoral morphology and loading stress in the femoral shaft by nonlinear CT/FEA. RESULTS Femoral bowing in the mid-shaft AFF group was significantly greater (lateral bowing, p<0.0001; anterior bowing, p<0.01). Femoral neck-shaft angle in the subtrochanteric AFF group was significantly smaller (p<0.001). On CT/FEA, both the mid-shaft and subtrochanteric AFF group showed maximum tensile stress located adjacent to the fracture site. Quantitatively, there was a correlation between femoral bowing and the ratio of tensile stress, which was calculated between the mid-shaft and subtrochanteric region (lateral bowing, r=0.6373, p<0.0001; anterior bowing, r=-0.5825, p<0.001). CONCLUSIONS CT/FEA demonstrated that tensile stress by loading stress can cause AFF. The location of AFF injury could be determined by individual stress distribution influenced by femoral bowing and neck-shaft angle.
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Affiliation(s)
- Yoto Oh
- Department of Orthopaedic and Trauma Research, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
| | - Koji Fujita
- Department of Orthopaedic and Spinal Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Yoshiaki Wakabayashi
- Department of Orthopaedic Surgery, Yokohama City Minato Red Cross Hospital, Kanagawa, Japan
| | - Yoshiro Kurosa
- Department of Orthopaedic Surgery, Saku Central Hospital, Nagano, Japan
| | - Atsushi Okawa
- Department of Orthopaedic and Spinal Surgery, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
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Bögl HP, Aspenberg P, Schilcher J. Undisturbed local bone formation capacity in patients with atypical femoral fractures: a case series. Osteoporos Int 2017; 28:2439-2444. [PMID: 28474166 DOI: 10.1007/s00198-017-4058-4] [Citation(s) in RCA: 5] [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: 01/10/2017] [Accepted: 04/12/2017] [Indexed: 01/13/2023]
Abstract
UNLABELLED We excised the fracture site in 8 patients with incomplete atypical femoral fractures by drilling an 11-mm-diameter hole. New bone formation could be seen in the hole within a normal time frame. Delayed healing of these fractures might be unrelated to an impaired capacity to form bone. INTRODUCTION Incomplete atypical femoral fractures (undisplaced cracks) heal slowly or not at all, and often progress to a complete fracture with minimal trauma. The impaired healing has been attributed to an impaired biologic healing capacity related to bisphosphonate use, or, alternatively, to the mechanical environment within the fracture crack. This study aimed to investigate the capacity for bone formation after resection of the fracture site. METHODS Between 2008 and 2014, we recruited eight patients with incomplete atypical femoral fractures. All used oral bisphosphonates before the fracture for on average 8 years (range 4 to 15) and complained of thigh pain. The fractures were stabilized with reamed cephalomedullary nails. During surgery, the fracture site in the lateral cortex was resected with a cylindrical drill (diameter 11.5 mm). The cylindrical cortical defect allowed radiographic evaluation of new bone formation, and the patients were followed clinically and radiologically for 24 months (range 15 to 92). RESULTS After 3 months, newly formed bone could be seen in the cortical defects in all patients. After 13-26 months, the previous defects showed continuous cortical bone. At final follow-up, all patients reported full recovery of pre-surgical complaints. No complications occurred and no reoperations were performed. CONCLUSIONS New bone formation occurred within a time frame that appears normal for healing of cortical bone defects. This suggests that the capacity to form new bone is intact.
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Affiliation(s)
- H P Bögl
- Department of Experimental and Clinical Medicine, Faculty of Health Science, Linköping University, SE-581 85, Linköping, Sweden
| | - P Aspenberg
- Department of Experimental and Clinical Medicine, Faculty of Health Science, Linköping University, SE-581 85, Linköping, Sweden
| | - J Schilcher
- Department of Orthopedic Surgery, Gävle hospital, SE-80 324, Gävle, Sweden.
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Abstract
PURPOSE OF REVIEW Bisphosphonates are used widely for the treatment of osteoporosis and prevention of fractures. Although generally well tolerated and effective, bisphosphonates (and denosumab, a newer antiresorptive agent) have been associated with unusual fractures of the femoral shaft. RECENT FINDINGS New information about the incidence, pathophysiology, and management of atypical femoral fractures (AFFs) are reviewed. Histomorphometric studies have shown variable amounts of bone turnover suppression, but new studies suggest that healing near bone cracks may not occur in patients with AFF. Some studies suggest that hip and femur geometry make certain people more at risk for AFF. In some but not all studies, the risk of AFF appears to be related to duration of treatment. Thus, the benefit/risk ratio needs to be reassessed as bisphosphonate therapy is prolonged. SUMMARY If we can better understand the pathogenesis of AFF, it may be possible to identify those patients at highest risk. In the meantime, clinicians must periodically assess risk for osteoporotic fracture versus risk for AFF in managing patients with osteoporosis.
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Affiliation(s)
- Robert A Adler
- Endocrinology and Metabolism (111P), McGuire Veterans Affairs Medical Center, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA
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