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Zdero R, Brzozowski P, Schemitsch EH. Biomechanical properties of artificial bones made by Sawbones: A review. Med Eng Phys 2023; 118:104017. [PMID: 37536838 DOI: 10.1016/j.medengphy.2023.104017] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/23/2023] [Accepted: 06/27/2023] [Indexed: 08/05/2023]
Abstract
Biomedical engineers and physicists frequently use human or animal bone for orthopaedic biomechanics research because they are excellent approximations of living bone. But, there are drawbacks to biological bone, like degradation over time, ethical concerns, high financial costs, inter-specimen variability, storage requirements, supplier sourcing, transportation rules, etc. Consequently, since the late 1980s, the Sawbones® company has been one of the world's largest suppliers of artificial bones for biomechanical testing that counteract many disadvantages of biological bone. There have been many published reports using these bone analogs for research on joint replacement, bone fracture fixation, spine surgery, etc. But, there exists no prior review paper on these artificial bones that gives a comprehensive and in-depth look at the numerical data of interest to biomedical engineers and physicists. Thus, this paper critically reviews 25 years of English-language studies on the biomechanical properties of these artificial bones that (a) characterized unknown or unreported values, (b) validated them against biological bone, and/or (c) optimized different design parameters. This survey of data, advantages, disadvantages, and knowledge gaps will hopefully be useful to biomedical engineers and physicists in developing mechanical testing protocols and computational finite element models.
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Affiliation(s)
- Radovan Zdero
- Orthopaedic Biomechanics Lab, Victoria Hospital, London, ON, Canada
| | - Pawel Brzozowski
- Orthopaedic Biomechanics Lab, Victoria Hospital, London, ON, Canada.
| | - Emil H Schemitsch
- Orthopaedic Biomechanics Lab, Victoria Hospital, London, ON, Canada; Division of Orthopaedic Surgery, Western University, London, ON, Canada
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2
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Yuan D, Wu Z, Luo S, Zou Q, Zou Z, Ye C. Impact of Femoral Neck Cortical Bone Defect Induced by Core Decompression on Postoperative Stability: A Finite Element Analysis. BIOMED RESEARCH INTERNATIONAL 2022; 2022:3667891. [PMID: 35647189 PMCID: PMC9142285 DOI: 10.1155/2022/3667891] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 04/24/2022] [Accepted: 05/04/2022] [Indexed: 11/18/2022]
Abstract
Objective To analyze the impact of femoral neck cortical bone defect induced by core decompression on postoperative biomechanical stability using the finite element method. Methods Five finite element models (FEMs) were established, including the standard operating model and four models of cortical bone defects at different portions of the femoral neck (anterior, posterior, superior, and inferior). The maximum stress of the proximal femur was evaluated during normal walking and walking downstairs. Results Under both weight-bearing conditions, the maximum stress values of the five models were as follows: femoral neck (inferior) > femoral neck (superior) > femoral neck (posterior) > femoral neck (anterior) > standard operation. Stress concentration occurred in the areas of femoral neck cortical bone defect. Under normal walking, the maximum stress of four bone defect models and its increased percentage comparing the standard operation were as follows: anterior (17.17%), posterior (39.02%), superior (57.48%), and inferior (76.42%). The maximum stress was less than the cortical bone yield strength under normal walking conditions. Under walking downstairs, the maximum stress of four bone defect models and its increased percentage comparing the standard operation under normal walking were as follows: anterior (36.75%), posterior (67.82%), superior (83.31%), and inferior (103.65%). Under walking downstairs conditions, the maximum stress of bone defect models (anterior, posterior, and superior) was less than the yield strength of cortical bone, while the maximum stress of bone defect model (inferior) excessed yield strength value. Conclusions The femoral neck cortical bone defect induced by core decompression can carry out normal walking after surgery. To avoid an increased risk of fracture after surgery, walking downstairs should be avoided when the cortical bone defect is inferior to the femoral neck except for the other three positions (anterior, posterior, and superior).
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Affiliation(s)
- Daizhu Yuan
- Department of Orthopaedics, The Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
- Center for Tissue Engineering and Stem Cells, Guizhou Medical University, Guiyang 550004, China
- Sports Medicine, The Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
| | - Zhanyu Wu
- Department of Orthopaedics, The Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
- Center for Tissue Engineering and Stem Cells, Guizhou Medical University, Guiyang 550004, China
| | - Siwei Luo
- Department of Orthopaedics, The Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
- Center for Tissue Engineering and Stem Cells, Guizhou Medical University, Guiyang 550004, China
| | - Qiang Zou
- Department of Orthopaedics, The Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
- Center for Tissue Engineering and Stem Cells, Guizhou Medical University, Guiyang 550004, China
| | - Zihao Zou
- Department of Orthopaedics, The Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
- Center for Tissue Engineering and Stem Cells, Guizhou Medical University, Guiyang 550004, China
| | - Chuan Ye
- Department of Orthopaedics, The Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China
- Center for Tissue Engineering and Stem Cells, Guizhou Medical University, Guiyang 550004, China
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3
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Shinoda Y, Sawada R, Ishibashi Y, Akiyama T, Zhang L, Hirai T, Oka H, Ohki T, Ikegami M, Okajima K, Okuma T, Kobayashi H, Goto T, Haga N, Tanaka S. Prediction of pathological fracture in patients with lower limb bone metastasis using computed tomography imaging. Clin Exp Metastasis 2020; 37:607-616. [PMID: 32737738 DOI: 10.1007/s10585-020-10053-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/26/2020] [Indexed: 10/23/2022]
Abstract
Lower limb pathological fractures caused by bone metastases can severely impair activities of daily living, so recognizing fracture risk is essential. Medial cortical involvement (MCI) in the proximal femur has been demonstrated to affect bone strength in biomechanical studies, but it has not been investigated in real patients. Between 2012 and 2019, 161 bone metastases with computed tomography (CT) images were retrospectively examined. Twenty-nine fractures were observed including 14 metastases with pathological fractures at the first examination, and prophylactic surgery was performed for 50 metastases. We extracted clinicopathological data using CT images, including patient's background, MCI in the proximal femur, site, size, circumferential cortical involvement (CCI), pain, and nature of metastasis. Cox proportional hazard regression analyses were performed, and we created integer scores for predicting fractures. We revealed that MCI, CCI, lytic dominant lesion, and pain were significant factors by univariate analyses. By multivariable analysis, MCI and each 25% CCI were significant and integer score 1 was assigned based on hazard ratio. The full score was four points, with MCI in the proximal femur (one point) and ≥ 75% CCI (three points). With integer score two, sensitivity was 88.9% and specificity was 81.2% for predicting fracture within 60 days. In conclusion, MCI and CCI examined by CT images were the risk factors for pathological fracture. CCI ≥ 50% is a widely known risk factor, but in addition, it may be better to consider surgery if MCI in the proximal femur is observed in metastasis with 25-50% CCI.
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Affiliation(s)
- Yusuke Shinoda
- Department of Rehabilitation Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan. .,Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.
| | - Ryoko Sawada
- Department of Rehabilitation Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.,Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yuki Ishibashi
- Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.,Department of Musculoskeletal Oncology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan
| | - Toru Akiyama
- Department of Orthopaedic Surgery, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Liuzhe Zhang
- Department of Orthopaedic Surgery, Saitama Medical Center, Jichi Medical University, Saitama, Japan
| | - Toshihide Hirai
- Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan.,Department of Musculoskeletal Oncology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan
| | - Hiroyuki Oka
- Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical & Research Center, Faculty of Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Takahiro Ohki
- Department of Rehabilitation Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.,Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Masachika Ikegami
- Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Koichi Okajima
- Department of Musculoskeletal Oncology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan
| | - Tomotake Okuma
- Department of Musculoskeletal Oncology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan
| | - Hiroshi Kobayashi
- Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Takahiro Goto
- Department of Musculoskeletal Oncology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan
| | - Nobuhiko Haga
- Department of Rehabilitation Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Sakae Tanaka
- Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
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4
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Johnson JE, Brouillette MJ, Permeswaran PT, Miller BJ, Goetz JE. Simulated lesions representative of metastatic disease predict proximal femur failure strength more accurately than idealized lesions. J Biomech 2020; 106:109825. [PMID: 32517984 DOI: 10.1016/j.jbiomech.2020.109825] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 04/22/2020] [Accepted: 05/05/2020] [Indexed: 11/30/2022]
Abstract
Metastatic disease in bone is characterized by highly amorphous and variable lesion geometry, with increased fracture risk. Assumptions of idealized lesion geometry made in previous finite element (FE) studies of metastatic disease in the proximal femur may not sufficiently capture effects of local stress/strain concentrations on predicted failure strength. The goal of this study was to develop and validate a FE failure model of the proximal femur incorporating artificial defects representative of physiologic metastatic disease. Data from 11 cadaveric femur specimens were randomly divided into either a training set (n = 5) or a test set (n = 6). Clinically representative artificial defects were created, and the femurs were loaded to failure under offset torsion. Voxel-based FE models replicating the experimental setup were created from the training set pre-fracture computed tomography data. Failure loads from the linear model with maximum principal strain failure criterion correlated best with the experimental data (R2 = 0.86, p = 0.024). The developed model was found to be reliable when applied to the test dataset with a relatively low RMSE of 46.9 N, mean absolute percent error of 12.7 ± 17.1%, and cross-validation R2 = 0.88 (p < 0.001). Models simulating realistic lesion geometry explained an additional 26% of the variance in experimental failure load compared to idealized lesion models (R2 = 0.62, p = 0.062). Our validated automated FE model representative of physiologic metastatic disease may improve clinical fracture risk prediction and facilitate research studies of fracture risk during functional activities and with treatment interventions.
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Affiliation(s)
- Joshua E Johnson
- Department of Orthopedics and Rehabilitation, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA.
| | - Marc J Brouillette
- Department of Orthopedics and Rehabilitation, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | | | - Benjamin J Miller
- Department of Orthopedics and Rehabilitation, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Jessica E Goetz
- Department of Orthopedics and Rehabilitation, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA; Department of Biomedical Engineering, University of Iowa, USA
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Shinoda Y, Kobayashi H, Kaneko M, Ohashi S, Bessho M, Hayashi N, Oka H, Imanishi J, Sawada R, Ogura K, Tanaka S, Haga N, Kawano H. Prediction of the pathological fracture risk during stance and fall-loading configurations for metastases in the proximal femur, using a computed tomography-based finite element method. J Orthop Sci 2019; 24:1074-1080. [PMID: 31521453 DOI: 10.1016/j.jos.2019.08.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 07/20/2019] [Accepted: 08/16/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND It is important to assess the fracture risk associated with metastasis in the proximal femur. The study aimed to clarify the effect of tumor location on the risk of pathological fracture of the proximal femur and investigate the fracture risk not only in the stance-loading configuration (SC), but also in the fall-loading configuration (FC) using a computed tomography (CT)-based finite element (FE) method based on a simulated metastatic model. METHODS The axial CT scans of the proximal femora of non-osteoporotic healthy men (n = 4; age range, 42-48 years) and osteoporotic post-menopausal women (n = 4; age range, 69-78 years) were obtained with a calibration phantom, from which the three-dimensional FE models were constructed. A single 15-mm-diameter spherical void simulating a tumor was created at various locations from the neck to subtrochanteric level. Nonlinear FE analyses were performed. RESULTS The mean predicted fracture loads without spherical voids in the SC were 7700 N in men and 4370 N in women. With the void at the medial femoral neck and in the region anteromedial to lesser trochanter, the mean predicted fracture load significantly reduced to 51.3% and 59.4% in men and 34.1% and 64.5% in women, respectively. The mean predicted fracture loads without a spherical void in the FC were 2500 N in men and 1862 N in women. With the void at the medial and posterior femoral neck, the predicted fracture load was significantly reduced to 65.7% and 79.7% in men and 48.3% and 65.4% in women, respectively. CONCLUSIONS These results showed that the risk of pathologic fracture was quite high in both the SC and FC when the lytic lesion existed along the principal compressive trabecular trajectory or posterior neck. Prophylactic intervention should be considered for metastases at these locations.
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Affiliation(s)
- Yusuke Shinoda
- Department of Rehabilitation Medicine, The University of Tokyo Hospital, Tokyo, Japan; Department of Orthopaedic Surgery, The University of Tokyo Hospital, Tokyo, Japan
| | - Hiroshi Kobayashi
- Department of Orthopaedic Surgery, The University of Tokyo Hospital, Tokyo, Japan.
| | - Masako Kaneko
- Department of Orthopaedic Surgery, The University of Tokyo Hospital, Tokyo, Japan
| | - Satoru Ohashi
- Department of Orthopaedic Surgery, The University of Tokyo Hospital, Tokyo, Japan
| | - Masahiko Bessho
- Department of Orthopaedic Surgery, Ichikawa Hospital, International University of Health and Welfare, Chiba, Japan
| | - Naoto Hayashi
- Department of Computational Diagnostic Radiology and Preventive Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Hiroyuki Oka
- Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical & Research Center, Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Jungo Imanishi
- Department of Orthopaedic Oncology and Surgery, Saitama Medical University International Medical Center, Saitama, Japan
| | - Ryoko Sawada
- Department of Orthopaedic Surgery, The University of Tokyo Hospital, Tokyo, Japan
| | - Koichi Ogura
- Department of Orthopaedic Surgery, The University of Tokyo Hospital, Tokyo, Japan
| | - Sakae Tanaka
- Department of Orthopaedic Surgery, The University of Tokyo Hospital, Tokyo, Japan
| | - Nobuhiko Haga
- Department of Rehabilitation Medicine, The University of Tokyo Hospital, Tokyo, Japan
| | - Hirotaka Kawano
- Department of Orthopaedic Surgery, Teikyo University School of Medicine, Tokyo, Japan
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6
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Howard EL, Cool P, Cribb GL. Prediction of pathological fracture in patients with metastatic disease of the lower limb. Sci Rep 2019; 9:14133. [PMID: 31575994 PMCID: PMC6773760 DOI: 10.1038/s41598-019-50636-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 09/16/2019] [Indexed: 01/27/2023] Open
Abstract
The aim of this study was to investigate if the risk of pathological fracture can be predicted with the proportion of body weight that can be put through the affected leg in patients with metastatic bone disease of the lower limb. A prospective observational study was conducted in patients with metastatic disease in the lower limb. Receiver Operator Characteristic curves were used to identify the optimum threshold level of single stance weight bearing to predict fracture and compared to the Mirels score. Patients who underwent surgery could weight bear significantly less than those who did not have surgical intervention. The optimum threshold to predict pathological fracture was 85% of total body weight. No patient below the threshold level of 85% single stance body weight sustained a pathological fracture. The use of single stance body weight can be a useful in conjunction with the Mirels score to predict pathological fracture. If less than 85% of total body weight can be put through the affected limb, the risk of fracture increases, and consideration of treatment is suggested.
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Affiliation(s)
- Emma L Howard
- School of Medicine, Keele University, Keele, ST5 5BG, UK
| | - Paul Cool
- Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation Trust, Gobowen, SY10 7A, UK. .,School of Medicine, Keele University, Keele, ST5 5BG, UK.
| | - Gillian L Cribb
- Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation Trust, Gobowen, SY10 7A, UK.,University of Manchester, Oxford Road, Manchester, M13 9PL, UK
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7
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Rajapakse CS, Gupta N, Evans M, Alizai H, Shukurova M, Hong AL, Cruickshank NJ, Tejwani N, Egol K, Honig S, Chang G. Influence of bone lesion location on femoral bone strength assessed by MRI-based finite-element modeling. Bone 2019; 122:209-217. [PMID: 30851438 PMCID: PMC6486650 DOI: 10.1016/j.bone.2019.03.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 02/22/2019] [Accepted: 03/05/2019] [Indexed: 12/21/2022]
Abstract
Currently, clinical determination of pathologic fracture risk in the hip is conducted using measures of defect size and shape in the stance loading condition. However, these measures often do not consider how changing lesion locations or how various loading conditions impact bone strength. The goal of this study was to determine the impact of defect location on bone strength parameters in both the sideways fall and stance-loading conditions. We recruited 20 female subjects aged 48-77 years for this study and performed MRI of the proximal femur. Using these images, we simulated 10-mm pathologic defects in greater trochanter, superior, middle, and inferior femoral head, superior, middle, and inferior femoral neck, and lateral, middle, and medial proximal diaphysis to determine the effect of defect location on change in bone strength by performing finite element analysis. We compared the effect of each osteolytic lesion on bone stiffness, strength, resilience, and toughness. For the sideways fall loading, defects in the inferior femoral head (12.21%) and in the greater trochanter (6.43%) resulted in the greatest overall reduction in bone strength. For the stance loading, defects in the mid femoral head (-7.91%) and superior femoral head (-7.82%) resulted in the greatest overall reduction in bone strength. Changes in stiffness, yield force, ultimate force, resilience, and toughness were not found to be significantly correlated between the sideways fall and stance-loading for the majority of defect locations, suggesting that calculations based on the stance-loading condition are not predictive of the change in bone strength experienced in the sideways fall condition. While stiffness was significantly related to yield force (R2 > 0.82), overall force (R2 > 0.59), and resilience (R2 > 0.55), in both, the stance-loading and sideways fall conditions for most defect locations, stiffness was not significantly related to toughness. Therefore, structure-dependent measure such as stiffness may not fully explain the post-yield measures, which depend on material failure properties. The data showed that MRI-based models have the sensitivity to determine the effect of pathologic lesions on bone strength.
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Affiliation(s)
| | - Nishtha Gupta
- University of Pennsylvania, Philadelphia, PA, United States of America
| | - Marissa Evans
- University of Pennsylvania, Philadelphia, PA, United States of America
| | - Hamza Alizai
- New York University, New York, NY, United States of America
| | - Malika Shukurova
- University of Pennsylvania, Philadelphia, PA, United States of America
| | - Abigail L Hong
- University of Pennsylvania, Philadelphia, PA, United States of America
| | | | - Nirmal Tejwani
- New York University, New York, NY, United States of America
| | - Kenneth Egol
- New York University, New York, NY, United States of America
| | - Stephen Honig
- New York University, New York, NY, United States of America
| | - Gregory Chang
- New York University, New York, NY, United States of America
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8
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Kawabata Y, Matsuo K, Nezu Y, Kamiishi T, Inaba Y, Saito T. The risk assessment of pathological fracture in the proximal femur using a CT-based finite element method. J Orthop Sci 2017; 22:931-937. [PMID: 28688810 DOI: 10.1016/j.jos.2017.05.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Revised: 04/18/2017] [Accepted: 05/23/2017] [Indexed: 02/09/2023]
Abstract
BACKGROUND Patients who have lytic bone lesions in their proximal femurs are at risk for pathological fracture. Lesions with high fracture risk are surgically treated using prophylactic osteosynthesis, whereas low-risk lesions are treated conservatively. However, it is difficult to discriminate between high- and low-risk lesions based on clinical and radiographic findings. The computed tomography (CT)-based finite element (FE) models are useful for predicting the fracture load on proximal femoral lytic lesions. MATERIALS AND METHODS FE models were constructed from the quantitative CT scans of the femurs using software that created individual bone shapes and density distributions. Three independent observers measured the lesion size, Mirels' score, and thickness of the proximal femur along the horizontal plane. The predictive risk values of the proximal femur measured using the CT-based FE analysis were statistically compared. RESULTS The patients were divided into two groups (high and low risk). The mean fracture load was significantly higher in the high-risk group than in the low-risk group (5395 ± 525 N, 2622 ± 364 N, respectively, p = 0.0003). No significant differences in age, body weight, lesion size or Mirels' score were observed between groups. However, the thickness of the medial cortex in the high-risk group according to the FE analysis was significantly thinner than that in the low-risk group. Furthermore, the medial cortex thickness was positively correlated with the predicted fracture load. An optimal cut-off value of 3.67 mm for the thickness of the inner cortex resulted in 100% sensitivity and 75.1% specificity values for classifying the patients based on their fracture risk. CONCLUSIONS Our findings indicate that the FE method is useful for the prediction of the pathological fracture. This method shows a versatile potential for the prediction of pathological fracture and might aid in judging the optimal treatment to prevent fracture.
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Affiliation(s)
- Yusuke Kawabata
- Department of Orthopaedic Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
| | - Kosuke Matsuo
- Department of Orthopaedic Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
| | - Yutaka Nezu
- Department of Orthopaedic Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Takayuki Kamiishi
- Department of Orthopaedic Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yutaka Inaba
- Department of Orthopaedic Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomoyuki Saito
- Department of Orthopaedic Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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9
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Benca E, Patsch JM, Mayr W, Pahr DH, Windhager R. The insufficiencies of risk analysis of impending pathological fractures in patients with femoral metastases: A literature review. Bone Rep 2016; 5:51-56. [PMID: 28326347 PMCID: PMC4926839 DOI: 10.1016/j.bonr.2016.02.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 02/23/2016] [Accepted: 02/24/2016] [Indexed: 01/30/2023] Open
Abstract
Purpose Pathologic fractures in patients with bone metastases are a common problem in clinical orthopaedic routine. On one hand recognition of metastatic lesions, which are at a high risk of fracture, is essential for timely prophylactic fixation, while on the other hand patients with a low risk of pathologic fractures should be spared from overtreatment. The purpose of this review is to identify all methods for fracture risk evaluation in patients with femoral metastases in the literature and to evaluate their predictive values in clinical applications. Methods A MEDLINE database literature research was conducted in order to identify clinical scoring systems, conclusions from prospective and retrospective radiologic and/or clinical studies, as well as data from biomechanical experiments, numerical computational methods, and computer simulations. Results The search identified 441 articles of which 18 articles met the inclusion criteria; 4 more articles were identified from citations of the primarily found studies. In principle there are two distinct methodologies, namely fracture risk prediction factors based on clinical and radiological data such as the most deployed the Mirels' score and fracture risk prediction based on engineering methods. Fracture risk prediction using Mirels' score, based on pure clinical data, shows a negative predictive value between 86 and 100%, but moderate to poor results in predicting non-impending fractures with a positive predictive value between 23 and 70%. Engineering methods provide a high accuracy (correlation coefficient between ex vivo and results from numerical calculations: 0.68 < r2 < 0.96) in biomechanical lab experiments, but have not been applied to clinical routine yet. Conclusion This review clearly points out a lack of adequate clinical methods for fracture risk prediction in patients with femoral metastases. Today's golden standard, the Mirels' score leads to an overtreatment. Whereas, engineering methods showed high potential but require a clinical validation. In future definition of patient-specific, quantitative risk factor based modelling methods could serve as useful decision support for individualized treatment strategies in patients with a metastatic lesion. There is a lack of adequate clinical methods for fracture risk prediction in patients with femoral metastases. Mirels' score fails to recognise non-impending fractures and leads to an overtreatment. Engineering methods showed high potential but require a clinical validation.
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Affiliation(s)
- Emir Benca
- Department of Orthopaedic Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Janina M Patsch
- Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Winfried Mayr
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Dieter H Pahr
- Institute for Lightweight Design and Structural Biomechanics, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Reinhard Windhager
- Department of Orthopaedic Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
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10
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Mei J, Liu S, Jia G, Cui X, Jiang C, Ou Y. Finite element analysis of the effect of cannulated screw placement and drilling frequency on femoral neck fracture fixation. Injury 2014; 45:2045-50. [PMID: 25172530 DOI: 10.1016/j.injury.2014.07.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 07/10/2014] [Accepted: 07/12/2014] [Indexed: 02/02/2023]
Abstract
BACKGROUND Positioning of the implanted cannulated screw is paramount for stable femoral neck fracture fixation. To avoid overdrilling, the aim of this study is to determine the optimum configuration of three cannulated screws employed in femoral neck fracture fixation. METHODS Using a CT scan from a 28 year old healthy male, several models of femoral neck fracture fixation were developed using finite element analysis. After drilling small holes (in either fixed or random patterns) for screw insertion, the mechanical stresses on the screws were compared for three fracture types. RESULTS The inverted isosceles triangle was found to be the best screw configuration. Using finite element analysis, the upper limit of drilling frequency and the maximum stress on the screws for 30°, 50°, and 70° drilling were 14, 16, and 19 times and 46.1MPa, 61.9MPa, and 51.0MPa, respectively. The upper limit of drilling frequency and the maximum stress on the screws for subcapital type, transcervical type, and basicervical type were 14, 16, and 40 times and 24.7MPa, 61.9MPa, and 113.5MPa, respectively. CONCLUSIONS Results of this study had supported the use of the inverted isosceles triangle as the best screw configuration for femoral neck fracture fixation. Screw position, Pauwels angle, and drilling frequency can all affect the mechanical strength of femoral neck fracture fixation.
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Affiliation(s)
- Jiong Mei
- Department of Orthopaedics, Tongji Hospital of Tongji University, Shanghai 200065, China.
| | - Shiwei Liu
- Department of Orthopaedics, Tongji Hospital of Tongji University, Shanghai 200065, China
| | - Guangyao Jia
- Department of Orthopaedics, Tongji Hospital of Tongji University, Shanghai 200065, China
| | - Xueliang Cui
- Department of Orthopaedics, Tongji Hospital of Tongji University, Shanghai 200065, China
| | - Chao Jiang
- Department of Orthopaedics, Tongji Hospital of Tongji University, Shanghai 200065, China
| | - Yi Ou
- Department of Orthopaedics, Tongji Hospital of Tongji University, Shanghai 200065, China
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Creek AT, Ratner DA, Porter SE. Evaluation and treatment of extremity metastatic disease. Cancer Treat Res 2014; 162:151-70. [PMID: 25070235 DOI: 10.1007/978-3-319-07323-1_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Metastases can occur as part of the natural progression of a variety of malignancies and their mode of spread, manner of presentation, and prognosis are as variable as their primary sources. The ultimate goal of musculoskeletal treatment of skeletal metastases is to get the patient in question back to his or her previous level of function as soon as possible. Skeletal metastases are seldom life threatening and their treatment will rarely render someone cured of their primary disease. Nevertheless, involvement of a musculoskeletal specialist as a part of the multidisciplinary approach can and very often does provide significant improvement in patients' qualities of life. The purpose of this chapter is to discuss the evaluation of a patient with suspected metastatic disease involving the musculoskeletal system and their pre-, intra-, and post surgical management as part of a multidisciplinary team.
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Affiliation(s)
- Aaron T Creek
- Department of Orthopaedic Surgery, Greenville Health System, Greenville, SC, 29605, USA
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Alexander GE, Gutierrez S, Nayak A, Palumbo BT, Cheong D, Letson GD, Santoni BG. Biomechanical model of a high risk impending pathologic fracture of the femur: lesion creation based on clinically implemented scoring systems. Clin Biomech (Bristol, Avon) 2013; 28:408-14. [PMID: 23597777 DOI: 10.1016/j.clinbiomech.2013.02.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 02/24/2013] [Accepted: 02/26/2013] [Indexed: 02/07/2023]
Abstract
BACKGROUND Multiple classifications combine objective and subjective measures to predict fracture risk through a metastatic lesion. In our literature review, no studies have attempted to validate this predicted fracture risk from a biomechanical perspective. The study goal was to evaluate proximal femur strength after creating osteolytic defects. We report a standardized technique to re-create a metastatic lesion. METHODS Eight femoral matched pairs were procured and a standardized technique was used to create an osteolytic femoral neck defect in one femur with the contralateral specimen serving as the control. Femurs were loaded to failure in a material testing machine at 2 mm/s. Failure load (N) and location of failure were documented. 3D finite element (FE) femur models with and without the lesions were developed to predict von Mises stresses in the femoral neck and compare between the two models. FINDINGS Femurs containing the osteolytic defect failed at significantly lower loads than the intact specimens in a reproducible manner (intact: 10.69 kN (3.09 SD); lesion: 5.56 kN (2.03 SD), p<0.001). The average reduction in failure load was 48%, and the fracture pattern was consistent in all specimens. FE model comparison similarly predicted significantly higher von Mises stress at the lesion. INTERPRETATION Our methods and pathologic fracture model represent the clinical parameters of metastatic bone disease and suggest a significant reduction in structural integrity of the lesion-containing femur. Prophylactic surgical fixation may be warranted clinically to reduce the risk of pathologic fracture. Our model technique is reproducible and may be used in future studies.
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Affiliation(s)
- Gerald E Alexander
- Department of Orthopaedic Surgery and Sports Medicine, University of South Florida College of Medicine, Tampa, FL USA
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