1
|
Lee-Confer J. Strength in arms: empowering older adults against the risk of slipping and falling-a theoretical perspective. Front Sports Act Living 2024; 6:1371730. [PMID: 38523707 PMCID: PMC10957654 DOI: 10.3389/fspor.2024.1371730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 03/01/2024] [Indexed: 03/26/2024] Open
Abstract
Background Slips and falls are a serious health concern, particularly among older adults. Current physical therapy protocols strengthen the legs to improve balance. However, arm movements help maintain balance during a slip incident. Understanding how arm movements improve balance may help clinicians develop more comprehensive fall-prevention protocols to improve patient outcomes. Clinical question What limitations exist in current fall prevention protocols for reducing falls in older adults during slip incidents, and what new strategies can enhance these outcomes? Key results Slip incidents often result in a sideways loss of balance, leading to hip fractures in older adults. During a slip, the legs do not produce sideways motion and are less effective in regaining balance in this direction. Contrary, the arms produce 100 + degrees of abduction and this motion reduces falls by 200%+ during a slip incident. Notably, older adults exhibit 35.7% decreased arm abduction acceleration responses compared to younger adults during a slip incident. This delay may be attributed to age-related decreases in type II fibers of the deltoid. High-velocity and ballistic training have been shown to improve the proportion and size of type II fibers as well as improve fall outcomes when focused on the lower extremities. Clinical application Therefore, I propose incorporating arm abductor training, alongside leg exercises, as a cost-effective and low-risk intervention to enhance the slip responses in older adults. In light of its minimal risk and considerable potential benefits, starting arm abductor exercises with older adults is a sensible move.
Collapse
Affiliation(s)
- Jonathan Lee-Confer
- Department of Physical Therapy, University of Arizona, Tucson, AZ, United States
| |
Collapse
|
2
|
Zhang M, Gong H, Zhang M. Prediction of femoral strength of elderly men based on quantitative computed tomography images using machine learning. J Orthop Res 2023; 41:170-182. [PMID: 35393726 DOI: 10.1002/jor.25334] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 03/07/2022] [Accepted: 03/22/2022] [Indexed: 02/04/2023]
Abstract
Hip fracture is the most common complication of osteoporosis, and its major contributor is compromised femoral strength. This study aimed to develop practical machine learning models based on clinical quantitative computed tomography (QCT) images for predicting proximal femoral strength. Eighty subjects with entire QCT data of the right hip region were randomly selected from the full MrOS cohorts, and their proximal femoral strengths were calculated by QCT-based finite element analysis (QCT/FEA). A total of 50 parameters of each femur were extracted from QCT images as the candidate predictors of femoral strength, including grayscale distribution, regional cortical bone mapping (CBM) measurements, and geometric parameters. These parameters were simplified by using feature selection and dimensionality reduction. Support vector regression (SVR) was used as the machine learning algorithm to develop the prediction models, and the performance of each SVR model was quantified by the mean squared error (MSE), the coefficient of determination (R2 ), the mean bias, and the SD of bias. For feature selection, the best prediction performance of SVR models was achieved by integrating the grayscale value of 30% percentile and specific regional CBM measurements (MSE ≤ 0.016, R2 ≥ 0.93); and for dimensionality reduction, the best prediction performance of SVR models was achieved by extracting principal components with eigenvalues greater than 1.0 (MSE ≤ 0.014, R2 ≥ 0.93). The femoral strengths predicted from the well-trained SVR models were in good agreement with those derived from QCT/FEA. This study provided effective machine learning models for femoral strength prediction, and they may have great potential in clinical bone health assessments.
Collapse
Affiliation(s)
- Meng Zhang
- Department of Engineering Mechanics, Nanling Campus, Jilin University, Changchun, China
| | - He Gong
- Department of Engineering Mechanics, Nanling Campus, Jilin University, Changchun, China
| | - Ming Zhang
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| |
Collapse
|
3
|
Kleiven S, Sahandifar P. Upright trunk and lateral or slight anterior rotation of the pelvis cause the highest proximal femur forces during sideways falls. Front Bioeng Biotechnol 2022; 10:1065548. [PMID: 36619387 PMCID: PMC9816430 DOI: 10.3389/fbioe.2022.1065548] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 12/08/2022] [Indexed: 12/24/2022] Open
Abstract
Whole-body models are historically developed for traffic injury prevention, and they are positioned accordingly in the standing or sitting configuration representing pedestrian or occupant postures. Those configurations are appropriate for vehicle accidents or pedestrian-vehicle accidents; however, they are uncommon body posture during a fall accident to the ground. This study aims to investigate the influence of trunk and pelvis angles on the proximal femur forces during sideways falls. For this purpose, a previously developed whole-body model was positioned into different fall configurations varying the trunk and pelvis angles. The trunk angle was varied in steps of 10° from 10 to 80°, and the pelvis rotation was changed every 5° from -20° (rotation toward posterior) to +20° (rotation toward anterior). The simulations were performed on a medium-size male (177 cm, 76 kg) and a small-size female (156 cm, 55 kg), representative for elderly men and women, respectively. The results demonstrated that the highest proximal femur force measured on the femoral head was reached when either male or female model had a 10-degree trunk angle and +10° anterior pelvis rotation.
Collapse
Affiliation(s)
- Svein Kleiven
- Neuronic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden,*Correspondence: Svein Kleiven,
| | | |
Collapse
|
4
|
Jiang Y, Zhang S. Whole-body vibration training does not improve the static balance of older women in the eyes-open state: A randomized trial. Technol Health Care 2022; 31:911-919. [PMID: 36442225 DOI: 10.3233/thc-220343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND: The impact of the current most effective vibration frequency on the balance ability of the elderly needs further verification. OBJECTIVE: To explore the effect of whole-body vibration training (WBVT) at three different frequencies on the balance ability of older women. METHODS: Ninety-three older women were randomly divided into low frequency (15 Hz), intermediate frequency (30 Hz), high-frequency (45 Hz), and control groups. The subjects in the vibration group underwent WBVT of the same amplitude twice a week for approximately 15 min per session. RESULTS: The speed of movement of the centre of pressure in the left and right directions with eyes closed was 7.9% lower in the static balance ability test in the intermediate frequency group after 36 weeks (P< 0.05). In the high frequency group, after WBVT, the total length of centre of pressure movement and speed of centre of pressure movement in the left and right directions were 9.9% and 8.7% lower, respectively, in the dynamic balance test (P< 0.05), and the speed of closed eye movement in the left and right directions was 12.5% lower in the static balance test (P< 0.05). CONCLUSION: WBVT at 30 and 45 Hz improved static balance in the right and left directions when older women had their eyes closed. WBVT at 45 Hz improved dynamic balance in the right and left directions in older women, and WBVT did not improve static balance in older women when their eyes were open.
Collapse
Affiliation(s)
- Yunfei Jiang
- Department of Kinesiology and Human Sciences, Sichuan Sports College, Chengdu, Sichuan, China
| | - Shuang Zhang
- Sichuan Academy of Medical Sciences, Sichuan Provincial People’s Hospital, Chengdu, Sichuan, China
| |
Collapse
|
5
|
Energy, Waves, and Forces in Bilateral Fracture of the Femoral Necks: Two Case Presentations and Updated Critical Review. Diagnostics (Basel) 2022; 12:diagnostics12112592. [PMID: 36359437 PMCID: PMC9689340 DOI: 10.3390/diagnostics12112592] [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: 09/12/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 11/30/2022] Open
Abstract
Two case reports and an updated critical review on bilateral fractures of the femoral neck are presented. Bilateral fractures of the femoral neck have been investigated for at least 80 years and are treated as rare cases. The primary cause is usually considered an external shock; however, aside from high energy shocks (e.g., falling and impact with hard, rigid surfaces, traffic accidents, etc.) the underlying causes of femoral neck frailty have not yet been fully understood. Although not exhaustive, the review spans cases reported as early as 1944 and compares their conclusions in line with medicine developments at the time of the reports until present. The discussion is perhaps controversial at times; it brings to the fore the energy balance between shock waves and stress waves. The two cases reported here add to the review, one highlighting the biomechanics, and the other supporting more recent findings on metabolic disorders, which ultimately lead to enhanced frailty of the femoral neck. Investigation of the fractures has been performed with X-ray radiographs, MRI, and CT, with a follow up using a Doppler US to check blood flow in the lower zone of the limbs. The second case was investigated both for fractures and metabolic diseases, e.g., type I diabetes and kidney failure (dialysis). In Case 1 the second fracture was not observable at the time of admission, and therefore two surgery operations were performed at seven days interval. Taperloc Complete prostheses (Zimmer Biomet) were applied. Case 2 suffered a second fracture in the right hip in the segment above the knee and required better fixation with cables. Despite this, she returned one month later with a new crack in the femur. Case 1 is a typical case of wear consequences on the biomechanics of the hill pad-tibia-femur-femoral neck system, where tension of the neck occurred due to a stress wave rather than a shock wave. This can be proven by the absence of a second fracture from the images first acquired, the only evidence being pain and walking difficulty. Case 2 shows that metabolic diseases can dramatically enhance the frequency of bilateral femoral neck fractures.
Collapse
|
6
|
Batcir S, Shani G, Shapiro A, Melzer I. Characteristics of step responses following varying magnitudes of unexpected lateral perturbations during standing among older people - a cross-sectional laboratory-based study. BMC Geriatr 2022; 22:400. [PMID: 35524172 PMCID: PMC9078012 DOI: 10.1186/s12877-022-03080-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 04/20/2022] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION The inability to recover from unexpected lateral loss of balance may be particularly relevant to the problem of falling. AIM We aimed to explore whether different kinematic patterns and strategies occur in the first recovery step in single-step trials in which a single step was required to recover from a fall, and in multiple-step trials in which more than one step was required to recover from a fall. In addition, in the multiple-step trials, we examined kinematic patterns of balance recovery where extra steps were needed to recover balance. METHODS Eighty-four older adults (79.3 ± 5.2 years) were exposed to unannounced right/left perturbations in standing that were gradually increased to trigger a recovery stepping response. We performed a kinematic analysis of the first recovery step of all single-step and multiple-step trials for each participant and of total balance recovery in the multiple-step trial. RESULTS Kinematic patterns and strategies of the first recovery step in the single-step trials were significantly dependent on the perturbation magnitude. It took a small, yet significantly longer time to initiate a recovery step and a significantly longer time to complete the recovery step as the magnitude increased. However, the first recovery step in the multiple-step trials showed no significant differences between different perturbation magnitudes; while, in total balance recovery of these trials, we observed a small, yet significant difference as the magnitude increased. CONCLUSIONS At relatively low perturbation magnitudes, i.e., single-step trials, older adults selected different first stepping strategies and kinematics as perturbation magnitudes increased, suggesting that this population activated pre-planned programs based on the perturbation magnitude. However, in the first recovery step of the multiple-step trials, i.e., high perturbation magnitudes, similar kinematic movement patterns were used at different magnitudes, suggesting a more rigid, automatic behavior, while the extra-steps were scaled to the perturbation magnitude. This suggest that older adults activate pre-planned programs based on the magnitude of the perturbation, even before the first step is completed..
Collapse
Affiliation(s)
- Shani Batcir
- Department of Physical Therapy, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Guy Shani
- Department of Information Systems, Faculty of Engineering Sciences, Ben-Gurion University, Beer-Sheva, Israel
| | - Amir Shapiro
- Department of Mechanical Engineering, Faculty of Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Itshak Melzer
- Department of Physical Therapy, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.
| |
Collapse
|
7
|
Abe S, Kouhia R, Nikander R, Narra N, Hyttinen J, Sievänen H. Effect of fall direction on the lower hip fracture risk in athletes with different loading histories: A finite element modeling study in multiple sideways fall configurations. Bone 2022; 158:116351. [PMID: 35131487 DOI: 10.1016/j.bone.2022.116351] [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: 06/11/2021] [Revised: 02/01/2022] [Accepted: 02/01/2022] [Indexed: 11/24/2022]
Abstract
Physical loading makes bones stronger through structural adaptation. Finding effective modes of exercise to improve proximal femur strength has the potential to decrease hip fracture risk. Previous proximal femur finite element (FE) modeling studies have indicated that the loading history comprising impact exercises is associated with substantially higher fracture load. However, those results were limited only to one specified fall direction. It remains thus unclear whether exercise-induced higher fracture load depends on the fall direction. To address this, using magnetic resonance images of proximal femora from 91 female athletes (mean age 24.7 years with >8 years competitive career) and their 20 non-athletic but physically active controls (mean age 23.7 years), proximal femur FE models were created in 12 different sideways fall configurations. The athletes were divided into five groups by typical loading patterns of their sports: high-impact (H-I: 9 triple- and 10 high-jumpers), odd-impact (O-I: 9 soccer and 10 squash players), high-magnitude (H-M: 17 powerlifters), repetitive-impact (R-I: 18 endurance runners), and repetitive non-impact (R-NI: 18 swimmers). Compared to the controls, the FE models showed that the H-I and R-I groups had significantly (p < 0.05) higher fracture loads, 11-17% and 22-28% respectively, in all fall directions while the O-I group had significantly 10-11% higher fracture loads in four fall directions. The H-M and R-NI groups did not show significant benefit in any direction. Also, the analyses of the minimum fall strength (MFS) among these multiple fall configurations confirmed significantly 15%, 11%, and 14% higher MFSs in these impact groups, respectively, compared to the controls. These results suggest that the lower hip fracture risk indicated by higher fracture loads in athletes engaged in high impact or repetitive impact sports is independent of fall direction whereas the lower fracture risk attributed to odd-impact exercise is more modest and specific to the fall direction. Moreover, in concordance with the literature, the present study also confirmed that the fracture risk increases if the impact is imposed on the more posterolateral aspect of the hip. The present results highlight the importance of engaging in the impact exercises to prevent hip fractures and call for retrospective studies to investigate whether specific impact exercise history in adolescence and young adulthood is also associated with lower incidence of hip fractures in later life.
Collapse
Affiliation(s)
- Shinya Abe
- Structural Mechanics, Faculty of Built Environment, Tampere University, Tampere, Finland.
| | - Reijo Kouhia
- Structural Mechanics, Faculty of Built Environment, Tampere University, Tampere, Finland
| | - Riku Nikander
- Gerontology Research Center, Faculty of Sports Sciences, University of Jyväskylä, Jyväskylä, Finland; Central Hospital of Central Finland, Jyväskylä, Finland
| | - Nathaniel Narra
- BioMediTech Unit, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Jari Hyttinen
- BioMediTech Unit, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Harri Sievänen
- The UKK Institute for Health Promotion Research, Tampere, Finland
| |
Collapse
|
8
|
Galliker ES, Laing AC, Ferguson SJ, Helgason B, Fleps I. The Influence of Fall Direction and Hip Protector on Fracture Risk: FE Model Predictions Driven by Experimental Data. Ann Biomed Eng 2022; 50:278-290. [PMID: 35129719 PMCID: PMC8847295 DOI: 10.1007/s10439-022-02917-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 01/02/2022] [Indexed: 11/25/2022]
Abstract
Hip fractures in older adults, which often lead to lasting impairments and an increased risk of mortality, are a major public health concern. Hip fracture risk is multi-factorial, affected by the risk of falling, the load acting on the femur, and the load the femur can withstand. This study investigates the influence of impact direction on hip fracture risk and hip protector efficacy. We simulated falls for 4 subjects, in 7 different impact directions (15° and 30° anterior, lateral, and 15°, 30°, 60°, and 90° posterior) at two different impact velocities (2.1 and 3.1 m/s), all with and without hip protector, using previously validated biofidelic finite element models. We found the highest number of fractures and highest fragility ratios in lateral and 15° posterior impacts. The hip protector attenuated femur forces by 23–49 % for slim subjects under impact directions that resulted in fractures (30° anterior to 30° posterior). The hip protector prevented all fractures (6/6) for 2.1 m/s impacts, but only 10% of fractures for 3.1 m/s impacts. Our results provide evidence that, regarding hip fracture risk, posterior-lateral impacts are as dangerous as lateral impacts, and they support the efficacy of soft-shell hip protectors for anterior- and posterior-lateral impacts.
Collapse
Affiliation(s)
| | - Andrew C Laing
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Canada
| | | | | | - Ingmar Fleps
- Institute for Biomechanics, ETH-Zurich, Zurich, Switzerland.
| |
Collapse
|
9
|
Sahandifar P, Kleiven S. Influence of nonlinear soft tissue modeling on the external and internal forces during lateral hip impacts. J Mech Behav Biomed Mater 2021; 124:104743. [PMID: 34474319 DOI: 10.1016/j.jmbbm.2021.104743] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 11/16/2022]
Abstract
Soft tissues in the hip region, which are typically considered the natural shock-absorbers during falls, attenuate the applied forces to the underlying hard tissue. The soft tissue thickness is, therefore, a significant parameter in the force attenuation. Another factor that could affect the assessment of the force attenuation in numerical simulations is the choice of constitutive model and material parameters for the soft tissue. Several constitutive models and parameters for muscle and adipose tissue were suggested in the published literature; however, the biofidelity of the proposed models for the lateral impacts has not been assessed yet. To achieve this purpose, we used a previously developed human body model named THUMS v4.02 and modified the mechanical properties and geometry of the soft tissues in the hip region. The simulations consisted of regional hip models and whole-body models. The biofidelity of the constitutive models of muscle and adipose tissue was determined objectively using the CORrelation and Analysis (CORA) rating. Moreover, the potential force attenuating effect of the adipose tissue thickness was investigated in the regional models. We collected and fitted several available nonlinear material models for muscle and adipose tissue and implemented them. The CORA ratings for several constitutive models for adipose tissue in the regional model were above 0.8. Among the muscle constitutive models, three Ogden models consistently rated above 0.58 for the whole-body model. Moreover, the impact forces in the selected adipose tissue model attenuated 47 N for every 1 mm increase in thickness. Overall, the choice of the nonlinear material model for the adipose and muscle tissue influences the external and internal force, and the difference between the material models is more pronounced when the thickness of the soft tissue increases.
Collapse
Affiliation(s)
- Pooya Sahandifar
- Neuronic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
| | - Svein Kleiven
- Neuronic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden
| |
Collapse
|
10
|
Luo Y. On challenges in clinical assessment of hip fracture risk using image-based biomechanical modelling: a critical review. J Bone Miner Metab 2021; 39:523-533. [PMID: 33423096 DOI: 10.1007/s00774-020-01198-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 12/11/2020] [Indexed: 10/22/2022]
Abstract
INTRODUCTION Hip fracture is a common health risk among elderly people, due to the prevalence of osteoporosis and accidental fall in the population. Accurate assessment of fracture risk is a crucial step for clinicians to consider patient-by-patient optimal treatments for effective prevention of fractures. Image-based biomechanical modeling has shown promising progress in assessment of fracture risk, and there is still a great possibility for improvement. The purpose of this paper is to identify key issues that need be addressed to improve image-based biomechanical modeling. MATERIALS AND METHODS We critically examined issues in consideration and determination of the four biomechanical variables, i.e., risk of fall, fall-induced impact force, bone geometry and bone material quality, which are essential for prediction of hip fracture risk. We closely inspected: limitations introduced by assumptions that are adopted in existing models; deficiencies in methods for construction of biomechanical models, especially for determination of bone material properties from bone images; problems caused by separate use of the variables in clinical study of hip fracture risk; availability of clinical information that are required for validation of biomechanical models. RESULTS AND CONCLUSIONS A number of critical issues and gaps were identified. Strategies for effectively addressing the issues were discussed.
Collapse
Affiliation(s)
- Yunhua Luo
- Department of Mechanical Engineering, University of Manitoba, 75A Chancellor's Circle, Winnipeg, MB, R3T 2N2, Canada.
- Department of Biomedical Engineering, University of Manitoba, 75A Chancellor's Circle, Winnipeg, MB, R3T 2N2, Canada.
| |
Collapse
|
11
|
Association of lower urinary tract symptoms and hip fracture in adults aged ≥ 50 years. PLoS One 2021; 16:e0246653. [PMID: 33657118 PMCID: PMC7928482 DOI: 10.1371/journal.pone.0246653] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 01/24/2021] [Indexed: 11/25/2022] Open
Abstract
Aim Lower urinary tract symptoms (LUTS) result in morbidities; however, their association with the occurrence of hip fracture is relatively unknown in the context of Asian studies. The purpose of the study was to investigate this link with the hip fracture risk in Taiwanese men and women aged 50 years and above. Materials and methods From 2000 through 2012, a population-based retrospective cohort study was conducted; claims data of 18,976 patients diagnosed with LUTS (dysuria, urinary retention, incontinence, and increased urinary frequency and urgency) were retrieved from Taiwan’s National Health Insurance Research Database. The patients were compared with 1:2 age, sex, and index year-matched controls (comparison group, n = 37,952). The incidence and hazard ratios of the hip fracture risk were calculated by the Cox proportional hazard regression models. Results The mean age was 66.2 ± 9.7 years, and the proportion of men was 58.1% in both study groups. Fractures occurred in 772 patients and 1,156 control subjects. The corresponding incidences were 7.0 and 5.0/1000 person-years. Compared to the control subjects, the patients with LUTS had an increased hip fracture risk [adjusted hazard ratio (aHR) = 1.29; 95% confidence interval (CI): 1.17–1.42]. LUTS was independently associated with an increased hip fracture risk in both men (aHR = 1.24; 95% CI: 1.08–1.42) and women (aHR = 1.34; 95% CI: 1.18–1.53) (p for interaction = 0.557). Similarly, the subgroup effect of age on hip fracture risks was not found (p for interaction = 0.665). Conclusion The study found LUTS was associated with an increased risk of hip fracture. Large-scale prospective studies in diverse populations are required to investigate causalities.
Collapse
|
12
|
The relationship between orthopedic clinical imaging and bone strength prediction. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2021. [DOI: 10.1016/j.medntd.2021.100060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
|
13
|
The effect of body configuration on the strain magnitude and distribution within the acetabulum during sideways falls: A finite element approach. J Biomech 2020; 114:110156. [PMID: 33302183 DOI: 10.1016/j.jbiomech.2020.110156] [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: 12/20/2019] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 01/17/2023]
Abstract
While the incidence of hip fractures has declined during the last decades, the incidence of acetabular fractures resulting from low-energy sideways falls has increased, and the mechanisms responsible for this trend remain unknown. Previous studies have suggested that body configuration during the impact plays an important role in a hip fracture. Thus, the aim of this study was to investigate the effect of body configuration angles (trunk tilt angle, trunk flexion angle, femur horizontal rotation angle, and femur diaphysis angle) on low-energy acetabular fractures via a parametric analysis. A computed tomography-based (CT) finite element model of the ground-proximal femur-pelvis complex was created, and strain magnitude, time-history response, and distribution within the acetabulum were evaluated. Results showed that while the trunk tilt angle and femur diaphysis angle have the greatest effect on strain magnitude, the direction of the fall (lateral vs. posterolateral) contributes to strain distribution within the acetabulum. The results also suggest that strain level and distribution within the proximal femur and acetabulum resulting from a sideways fall are not similar and, in some cases, even opposite. Taken together, our simulations suggest that a more horizontal trunk and femoral shaft at the impact phase can increase the risk of low-energy acetabular fractures.
Collapse
|
14
|
Jazinizadeh F, Quenneville CE. 3D Analysis of the Proximal Femur Compared to 2D Analysis for Hip Fracture Risk Prediction in a Clinical Population. Ann Biomed Eng 2020; 49:1222-1232. [PMID: 33123827 DOI: 10.1007/s10439-020-02670-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 10/20/2020] [Indexed: 01/22/2023]
Abstract
Due to the adverse impacts of hip fractures on patients' lives, it is crucial to enhance the identification of people at high risk through accessible clinical techniques. Reconstructing the 3D geometry and BMD distribution of the proximal femur could be beneficial in enhancing hip fracture risk predictions; however, it is associated with a high computational burden. It is also not clear whether it provides a better performance than 2D model analysis. Therefore, the purpose of this study was to compare the 2D and 3D model reconstruction's ability to predict hip fracture risk in a clinical population of patients. The DXA scans and CT scans of 16 cadaveric femurs were used to create training sets for the 2D and 3D model reconstruction based on statistical shape and appearance modeling. Subsequently, these methods were used to predict the risk of sustaining a hip fracture in a clinical population of 150 subjects (50 fractured, and 100 non-fractured) that were monitored for five years in the Canadian Multicentre Osteoporosis Study. 3D model reconstruction was able to improve the identification of patients who sustained a hip fracture more accurately than the standard clinical practice (by 40%). Also, the predictions from the 2D statistical model didn't differ significantly from the 3D ones (p > 0.76). These results indicated that to enhance hip fracture risk prediction in clinical practice implementing 2D statistical modeling has comparable performance with lower associated computational load.
Collapse
Affiliation(s)
- Fatemeh Jazinizadeh
- Department of Mechanical Engineering, McMaster University, ABB-C308, 1280 Main St. West, Hamilton, ON, L8S 4L8, Canada
| | - Cheryl E Quenneville
- Department of Mechanical Engineering, McMaster University, ABB-C308, 1280 Main St. West, Hamilton, ON, L8S 4L8, Canada.
- School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada.
| |
Collapse
|
15
|
Acceleration Magnitude at Impact Following Loss of Balance Can Be Estimated Using Deep Learning Model. SENSORS 2020; 20:s20216126. [PMID: 33126491 PMCID: PMC7663134 DOI: 10.3390/s20216126] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/16/2020] [Accepted: 10/22/2020] [Indexed: 11/17/2022]
Abstract
Pre-impact fall detection can detect a fall before a body segment hits the ground. When it is integrated with a protective system, it can directly prevent an injury due to hitting the ground. An impact acceleration peak magnitude is one of key measurement factors that can affect the severity of an injury. It can be used as a design parameter for wearable protective devices to prevent injuries. In our study, a novel method is proposed to predict an impact acceleration magnitude after loss of balance using a single inertial measurement unit (IMU) sensor and a sequential-based deep learning model. Twenty-four healthy participants participated in this study for fall experiments. Each participant worn a single IMU sensor on the waist to collect tri-axial accelerometer and angular velocity data. A deep learning method, bi-directional long short-term memory (LSTM) regression, is applied to predict a fall's impact acceleration magnitude prior to fall impact (a fall in five directions). To improve prediction performance, a data augmentation technique with increment of dataset is applied. Our proposed model showed a mean absolute percentage error (MAPE) of 6.69 ± 0.33% with r value of 0.93 when all three different types of data augmentation techniques are applied. Additionally, there was a significant reduction of MAPE by 45.2% when the number of training datasets was increased by 4-fold. These results show that impact acceleration magnitude can be used as an activation parameter for fall prevention such as in a wearable airbag system by optimizing deployment process to minimize fall injury in real time.
Collapse
|
16
|
Jazinizadeh F, Adachi JD, Quenneville CE. Advanced 2D image processing technique to predict hip fracture risk in an older population based on single DXA scans. Osteoporos Int 2020; 31:1925-1933. [PMID: 32415372 DOI: 10.1007/s00198-020-05444-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/29/2020] [Indexed: 01/04/2023]
Abstract
UNLABELLED A new technique to enhance hip fracture risk prediction in older adults was presented and assessed. The new method dramatically improved prediction at high specificity levels using only a standard clinical diagnostic scan. This has the potential to be implemented in clinical practice to enhance patient fragility diagnosis. INTRODUCTION Diagnosis of osteoporosis is based on the measurement of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA) scans. However, studies have shown this to be insufficient to accurately predict hip fractures. Therefore, complementary methods are needed to enhance hip fracture risk prediction to identify vulnerable patients. METHODS Hip DXA scans were obtained for 192 subjects from the Canadian Multicenter Osteoporosis Study (CaMos), 50 of whom had experienced a hip fracture within 5 years of the scan. 2D statistical shape and appearance modeling was performed to account for the effect of the femur's geometry and BMD distribution on hip fracture risk. Statistical shape modeling (SSM), and statistical appearance modeling (SAM) were also used separately to predict the fracture risk based solely on the femur's geometry and BMD distribution, respectively. Combined with BMD, age, and body mass index (BMI), logistic regression was performed to estimate the fracture risk over the 5-year period. RESULTS Using the new technique, hip fractures were correctly predicted in 78% of cases compared with 36% when using the T-score. The accuracy of the prediction was not greatly reduced when using SSM and SAM (78% and 74% correct, respectively). Various geometric and BMD distribution traits were identified in the fractured and non-fractured groups. CONCLUSION 2D SSAM can dramatically improve hip fracture prediction at high specificity levels and estimate the year of the impending fracture using standard clinical images. This has the potential to be implemented in clinical practice to estimate hip fracture risk.
Collapse
Affiliation(s)
- F Jazinizadeh
- Department of Mechanical Engineering, McMaster University, ABB-C308, 1280 Main St. West, Hamilton, Ontario, L8S 4L8, Canada
| | - J D Adachi
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - C E Quenneville
- Department of Mechanical Engineering, McMaster University, ABB-C308, 1280 Main St. West, Hamilton, Ontario, L8S 4L8, Canada.
- School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada.
| |
Collapse
|
17
|
Martel DR, Lysy M, Laing AC. Predicting population level hip fracture risk: a novel hierarchical model incorporating probabilistic approaches and factor of risk principles. Comput Methods Biomech Biomed Engin 2020; 23:1201-1214. [PMID: 32687412 DOI: 10.1080/10255842.2020.1793331] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Fall-related hip fractures are a major public health issue. While individual-level risk assessment tools exist, population-level predictive models could catalyze innovation in large-scale interventions. This study presents a hierarchical probabilistic model that predicts population-level hip fracture risk based on Factor of Risk (FOR) principles. Model validation demonstrated that FOR output aligned with a published dataset categorized by sex and hip fracture status. The model predicted normalized FOR for 100000 individuals simulating the Canadian older-adult population. Predicted hip fracture risk was higher for females (by an average of 38%), and increased with age (by15% per decade). Potential applications are discussed.
Collapse
Affiliation(s)
- Daniel R Martel
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Martin Lysy
- Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Andrew C Laing
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| |
Collapse
|
18
|
Kleiven S. Hip fracture risk functions for elderly men and women in sideways falls. J Biomech 2020; 105:109771. [PMID: 32423538 DOI: 10.1016/j.jbiomech.2020.109771] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 03/28/2020] [Accepted: 03/28/2020] [Indexed: 11/30/2022]
Abstract
Falls among the elderly cause a huge number of hip fractures world-wide. The objective is to generate hip fracture force risk functions for elderly women and men in sideways falls which can be used for determining effectiveness of fall prevention measures as well as for individual assessment of fracture risk at the clinics. A literature survey was performed and ten publications were identified who contained several hundred individual femoral neck fracture forces in sideways fall for both elderly women and men. Theoretical distributions were tested for goodness of fit against the pooled dataset with the Anderson-Darling test (AD-test) and root mean square errors (RMSE) were extracted. According to the AD-test, a Weibull distribution is a plausible model for the distribution of hip fracture forces. A simple, exponential two-parameter Weibull function was therefore proposed, having a RMSE below 2.2% compared to the experimental distribution for both men and women. It was demonstrated that elderly women only can endure nearly half the proximal femur force for 5 and 10% fracture risk as elderly men. It should be noted though, that women were found to have significantly lesser body height and body weight which would produce less impact force during falls from standing height. The proposed sex-specific hip fracture risk functions can be used for biomechanically optimizing hip protectors and safety floors and for determining their effectiveness as a fall prevention measure.
Collapse
Affiliation(s)
- Svein Kleiven
- Neuronic Engineering, KTH Royal Institute of Technology, Stockholm, Sweden
| |
Collapse
|
19
|
Byun M, Kim J, Kim M. Physical and Psychological Factors Affecting Falls in Older Patients with Arthritis. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17031098. [PMID: 32050468 PMCID: PMC7037137 DOI: 10.3390/ijerph17031098] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 02/05/2020] [Accepted: 02/07/2020] [Indexed: 11/16/2022]
Abstract
As the population ages, falls are becoming one of the leading causes of morbidity and mortality. Joint disease (either osteoarthritis or rheumatoid arthritis) is a well-known predictor of falls, and these medical conditions increase in accordance with the aging population. This study aimed to describe individual, physical, and psychological characteristics between older adults with and without a fall history. Further, we aimed to identify statistically significant physical or psychological factors associated with falls by controlling individual variables. We analyzed data from the 2014 Survey of Living Conditions and Welfare Needs of Korean Older Adults. Adults aged 65 years or over with doctor-diagnosed joint disease were eligible. A total of 2707 women and 784 men (n = 3491) were enrolled. Of these, 1174 patients suffered a fall within a year (average number of falls = 2.4). We adopted individual variable-adjusted models and found that limited activities of daily living (odds ratio (OR) 1.4, 95% confidence interval (CI) 1.04-1.87), fear of falling (OR 7.18, 95% CI 4.26-12.09), and depression (OR 1.28, 95% CI 1.09-1.50) significantly increased fall risks on logistic regression analysis. Our findings suggest that physical and psychological factors, especially the fear of falling, need to be addressed to prevent falls in elderly patients with arthritis.
Collapse
Affiliation(s)
- Mikyong Byun
- College of Nursing, Korea University, Anam-dong, Seongbuk-Gu, Seoul 02841, Korea; (M.B.); (J.K.)
| | - Jiyeon Kim
- College of Nursing, Korea University, Anam-dong, Seongbuk-Gu, Seoul 02841, Korea; (M.B.); (J.K.)
| | - Moonho Kim
- Department of Hematology and Oncology, Gangneung Asan Hospital, University of Ulsan College of Medicine, 38 Bangdong-gil, Sacheon-myeon, Gangneung-si, Gangwon-do 25440, Korea
- Correspondence: ; Tel.: +82-33-610-4265
| |
Collapse
|
20
|
Gratza SK, Chocano-Bedoya PO, Orav EJ, Fischbacher M, Freystätter G, Theiler R, Egli A, Kressig RW, Kanis JA, Bischoff-Ferrari HA. Influence of fall environment and fall direction on risk of injury among pre-frail and frail adults. Osteoporos Int 2019; 30:2205-2215. [PMID: 31377914 DOI: 10.1007/s00198-019-05110-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 07/24/2019] [Indexed: 12/29/2022]
Abstract
UNLABELLED In this prospective study, half of all falls resulted in injury. Pre-frail adults sustained more injuries, while more frail adults had injuries requiring hospitalization or fractures. Pre-frail adults fell more often when in movement compared with frail adults who fell more often when standing and in indoor public spaces. PURPOSE To assess prospectively how fall environment and direction are related to injury among pre-frail and frail adults. METHODS We included 200 community-dwelling adults with a prior fall (pre-frail, mean age 77 years) and 173 adults with acute hip fracture (frail, mean age 84 years; 77% community-dwelling). Falls were prospectively recorded using standardized protocols in monthly intervals, including date, time, fall direction and environment, and injury. We used logistic regression to assess the odds of injury adjusting for age, body mass index (BMI), and gender. RESULTS We recorded 513 falls and 331 fall-related injuries (64.5%) among the 373 participants. While the fall rate was similar between groups, pre-frail adults had more injuries (71% among pre-frail vs. 56% among frail, p = 0.0004) but a lower incidence of major injuries (9% among pre-frail vs. 27% among frail, p = 0.003). Pre-frail adults fell more often while in movement (84% among pre-frail vs. 55% among frail, p < 0.0001), and frail adults fell more often while standing (26% vs. 15% respectively, p = 0.01). The odds of injury among frail adults was increased 3.3-fold when falling sideways (OR = 3.29, 95% CI = 1.68-6.45) and 2.4-fold when falling in an indoor public space (OR = 2.35, 95% CI = 1.00-5.53), and was reduced when falling at home (OR = 0.55, 95% CI = 0.31-0.98). The odds of injury among pre-frail adults was not influenced by environment and was 53% lower when falling backwards (OR = 0.47, 95% CI = 0.26-0.82). CONCLUSION While pre-frail adults sustain more fall-related injuries, frail adults were more likely to sustain major injuries, especially when falling sideways or outside their home.
Collapse
Affiliation(s)
- S K Gratza
- Centre on Aging and Mobility, University Hospital Zurich, Waid City Hospital, and University of Zurich, Zurich, Switzerland
- Basel University Medicine of Aging, Felix-Platter Spital, Basel, Switzerland
| | - P O Chocano-Bedoya
- Centre on Aging and Mobility, University Hospital Zurich, Waid City Hospital, and University of Zurich, Zurich, Switzerland
| | - E J Orav
- Department of Biostatistics, Harvard School of Public Health, Boston, MA, USA
| | - M Fischbacher
- Centre on Aging and Mobility, University Hospital Zurich, Waid City Hospital, and University of Zurich, Zurich, Switzerland
- School of Allied Health Sciences, Griffith University, Gold Coast, Australia
| | - G Freystätter
- Centre on Aging and Mobility, University Hospital Zurich, Waid City Hospital, and University of Zurich, Zurich, Switzerland
- Department of Geriatrics and Aging Research, University Hospital Zurich, Raemistrasse 101, 8091, Zurich, Switzerland
| | - R Theiler
- Centre on Aging and Mobility, University Hospital Zurich, Waid City Hospital, and University of Zurich, Zurich, Switzerland
- Department of Geriatrics and Aging Research, University Hospital Zurich, Raemistrasse 101, 8091, Zurich, Switzerland
| | - A Egli
- Centre on Aging and Mobility, University Hospital Zurich, Waid City Hospital, and University of Zurich, Zurich, Switzerland
| | - R W Kressig
- Basel University Medicine of Aging, Felix-Platter Spital, Basel, Switzerland
| | - J A Kanis
- Mary McKillop Health Institute, Australian Catholic University, Melbourne, Australia
- Centre of Metabolic Bone Diseases, University of Sheffield Medical School, Sheffield, UK
| | - H A Bischoff-Ferrari
- Centre on Aging and Mobility, University Hospital Zurich, Waid City Hospital, and University of Zurich, Zurich, Switzerland.
- Department of Geriatrics and Aging Research, University Hospital Zurich, Raemistrasse 101, 8091, Zurich, Switzerland.
- University Clinic for Acute Geriatric Care, City Hospital Waid, Zurich, Switzerland.
| |
Collapse
|
21
|
Fleps I, Fung A, Guy P, Ferguson SJ, Helgason B, Cripton PA. Subject-specific ex vivo simulations for hip fracture risk assessment in sideways falls. Bone 2019; 125:36-45. [PMID: 31071479 DOI: 10.1016/j.bone.2019.05.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 04/17/2019] [Accepted: 05/04/2019] [Indexed: 12/18/2022]
Abstract
The risk of hip fracture of a patient due to a fall can be described from a mechanical perspective as the capacity of the femur to withstand the force that it experiences in the event of a fall. So far, impact forces acting on the lateral aspect of the pelvic region and femur strength have been investigated separately. This study used inertia-driven cadaveric impact experiments that mimic falls to the side from standing in order to evaluate the subject-specific force applied to the hip during impact and the fracture outcome in the same experimental model. Eleven fresh-frozen pelvis-femur constructs (6 female, 5 male, age = 77 years (SD = 13 years), BMI = 22.8 kg/m2 (SD = 7.8 kg/m2), total hip aBMD = 0.734 g/cm2 (SD = 0.149 g/cm2)), were embedded into soft tissue surrogate material that matched subject-specific mass and body shape. The specimens were attached to metallic lower-limb constructions with subject-specific masses and subjected to an inverted pendulum motion. Impact forces were recorded with a 6-axis force plate at 10,000 Hz and three dimensional deflections in the pelvic region were tracked with two high-speed cameras at 5000 Hz. Of the 11 specimens, 5 femur fractures and 3 pelvis fractures were observed. Three specimens did not fracture. aBMD alone did not reliably separate femur fractures from non-fractures. However, a mechanical risk ratio, which was calculated as the impact force divided by aBMD, classified specimens reliably into femur fractures and non-fractures. Single degree of freedom models, based on specimen kinetics, were able to predict subject-specific peak impact forces (RMSE = 2.55% for non-fractures). This study provides direct evidence relating subject-specific impact forces and subject-specific strength estimates and improves the assessment of the mechanical risk of hip fracture for a specific femur/pelvis combination in a sideways fall.
Collapse
Affiliation(s)
- Ingmar Fleps
- Institute for Biomechanics, ETH Zürich, Zürich, Switzerland; Orthopaedics and Injury Biomechanics Group, Departments of Mechanical Engineering and Orthopaedics and School of Biomedical Engineering, University of British Columbia, Vancouver, Canada.
| | - Anita Fung
- Institute for Biomechanics, ETH Zürich, Zürich, Switzerland; Orthopaedics and Injury Biomechanics Group, Departments of Mechanical Engineering and Orthopaedics and School of Biomedical Engineering, University of British Columbia, Vancouver, Canada
| | - Pierre Guy
- Division of Orthopaedic Trauma, Department of Orthopaedics, University of British Columbia, Vancouver, Canada
| | | | | | - Peter A Cripton
- Orthopaedics and Injury Biomechanics Group, Departments of Mechanical Engineering and Orthopaedics and School of Biomedical Engineering, University of British Columbia, Vancouver, Canada
| |
Collapse
|
22
|
Sarvi MN, Luo Y. Improving the prediction of sideways fall-induced impact force for women by developing a female-specific equation. J Biomech 2019; 88:64-71. [DOI: 10.1016/j.jbiomech.2019.03.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 03/01/2019] [Accepted: 03/12/2019] [Indexed: 11/29/2022]
|
23
|
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.
Collapse
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
| |
Collapse
|
24
|
Luo Y, Yang H. Assessment of hip fracture risk by cross-sectional strain-energy derived from image-based beam model. Clin Biomech (Bristol, Avon) 2019; 63:48-53. [PMID: 30831432 DOI: 10.1016/j.clinbiomech.2019.02.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 02/16/2019] [Accepted: 02/22/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Clinicians have been looking for a simple and effective biomechanical tool for the assessment of hip fracture risk. Dual-energy X-ray absorptiometry (DXA) is currently the primary bone imaging modality in clinic, and the engineering beam is the simplest model for a mechanical analysis. Therefore, we developed a DXA-based beam model for the above purpose. METHODS A beam model of the proximal femur was constructed from the subject's hip DXA image and denoted DXA-beam. Femur stiffness was calculated at cross-sections of interest using areal bone-mineral-density profile. Impact force induced in a sideways fall was applied as a critical loading. Fracture risk index at a cross-section was defined as the ratio of strain-energy induced by the impact force to the allowable strain-energy. A clinic cohort was used to study the discriminability of DXA-beam, which was measured by the area under the curve and odds ratio, both with 95% confidential interval. FINDINGS Fracture risk measured by DXA-beam model at the femoral neck [odds ratio 2.23, 95% confidence interval (1.83, 2.57)], inter-trochanter [2.49, (2.14, 3.25)] and sub-trochanter [2.82, (2.38, 3.51)] were strongly associated with hip fracture. The area under the curve by DXA-beam at the femoral neck [0.74, 95% confidence interval (0.70, 0.76)], inter-trochanter [0.77, (0.75, 0.82)] and sub-trochanter [0.76, (0.74, 0.81)] were higher than that by femoral neck bone mineral density [0.71, (0.65, 0.78)]. INTERPRETATION The DXA-beam model is a simple and yet effective mechanical model. It had promising performance in discrimination of fracture cases from controls.
Collapse
Affiliation(s)
- Yunhua Luo
- Department of Mechanical Engineering, University of Manitoba, Winnipeg, Canada; Department of Biomedical Engineering, University of Manitoba, Winnipeg, Canada.
| | - Huijuan Yang
- Department of Mechanical Engineering, University of Manitoba, Winnipeg, Canada
| |
Collapse
|
25
|
Fleps I, Enns-Bray WS, Guy P, Ferguson SJ, Cripton PA, Helgason B. On the internal reaction forces, energy absorption, and fracture in the hip during simulated sideways fall impact. PLoS One 2018; 13:e0200952. [PMID: 30114192 PMCID: PMC6095517 DOI: 10.1371/journal.pone.0200952] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 07/04/2018] [Indexed: 11/25/2022] Open
Abstract
The majority of hip fractures have been reported to occur as a result of a fall with impact to the greater trochanter of the femur. Recently, we developed a novel cadaveric pendulum-based hip impact model and tested two cadaveric femur-pelvis constructs, embedded in a soft tissue surrogate. The outcome was a femoral neck fracture in a male specimen while a female specimen had no fracture. The aim of the present study was, first, to develop a methodology for constructing and assessing the accuracy of explicit Finite Element Models (FEMs) for simulation of sideways falls to the hip based on the experimental model. Second, to use the FEMs for quantifying the internal reaction forces and energy absorption in the hip during impact. Third, to assess the potential of the FEMs in terms of separating a femoral fracture endpoint from a non-fracture endpoint. Using a non-linear, strain rate dependent, and heterogeneous material mapping strategy for bone tissue in these models, we found the FEM-derived results to closely match the experimental test results in terms of impact forces and displacements of pelvic video markers up to the time of peak impact force with errors below 10%. We found the internal reaction forces in the femoral neck on the impact side to be approximately 35% lower than the impact force measured between soft tissue and ground for both specimens. In addition, we found the soft tissue to be the component that absorbed the largest part of the energy of the tissue types in the hip region. Finally, we found surface strain patterns derived from FEM results to match the fracture location and extent based on post testing x-rays of the specimens. This is the first study with quantitative data on the energy absorption in the pelvic region during a sideways fall.
Collapse
Affiliation(s)
- Ingmar Fleps
- Institute for Biomechanics, ETH Zürich, Zürich, Switzerland
- * E-mail:
| | | | - Pierre Guy
- Division of Orthopaedic Trauma, Department of Orthopaedics, University of British Columbia, Vancouver, Canada
| | | | - Peter A. Cripton
- Orthopaedics and Injury Biomechanics Group, Department of Mechanical Engineering and Orthopaedics and School of Biomedical Engineering, University of British Columbia, Vancouver, Canada
| | - Benedikt Helgason
- Institute for Biomechanics, ETH Zürich, Zürich, Switzerland
- School of Science and Engineering, Reykjavik University, Reykjavik, Iceland
| |
Collapse
|
26
|
Fatal falls in the elderly and the presence of proximal femur fractures. Int J Legal Med 2018; 132:1699-1712. [PMID: 29882059 DOI: 10.1007/s00414-018-1876-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 05/29/2018] [Indexed: 01/24/2023]
Abstract
Fatal falls are frequent and seem to be an increasing problem in the elderly. Especially ground level falls (GLFs) and falls on or from stairs and steps (stairs falls) are worth examining for forensic classification and in order to improve the development of preventive measures. We retrospectively analyzed 261 fatal falls of elderly age 65 + years, which were autopsied at the Institute of Legal Medicine in Munich between 2008 and 2014. After careful screening, the sub-set of all 77 GLFs and 39 stairs falls were analyzed towards socio-demographic characteristics, fall circumstances, injuries, and circumstances of death. A subsequent analysis of GLF cases regarding the presence of proximal femur fractures (PFF) was performed. The injury pattern of the GLFs and the stairs falls clearly differ with a higher share of injuries to the lower extremities in the GLFs. However, the most severely injured body region was the head in both groups (62% of the stairs cases, 49% of the GLF cases). Alcohol as contributing to the fall was seen more frequently in the stairs falls. PFF were not seen in the stairs falls, but then in 18 GLF cases. Yet, for 17 among them (22% of 77), their hip fracture was the only serious injury leading to hospitalization and death. Only one GLF case was already found dead. This finding indicates a potential of avoiding up to 22% of the GLF fatalities by preventing hip fractures by optimized hip protectors or other measures, especially for the elderly aged 75 + years.
Collapse
|
27
|
Yang S, Luo Y, Yang L, Dall'Ara E, Eastell R, Goertzen AL, McCloskey EV, Leslie WD, Lix LM. Comparison of femoral strength and fracture risk index derived from DXA-based finite element analysis for stratifying hip fracture risk: A cross-sectional study. Bone 2018. [PMID: 29526781 DOI: 10.1016/j.bone.2018.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND Dual-energy X-ray absorptiometry (DXA)-based finite element analysis (FEA) has been studied for assessment of hip fracture risk. Femoral strength (FS) is the maximum force that the femur can sustain before its weakest region reaches the yielding limit. Fracture risk index (FRI), which also considers subject-specific impact force, is defined as the ratio of von Mises stress induced by a sideways fall to the bone yield stress over the proximal femur. We compared risk stratification for prior hip fracture using FS and FRI derived from DXA-based FEA. METHODS The study cohort included women aged ≥65years undergoing baseline hip DXA, with femoral neck T-scores <-1 and no osteoporosis treatment; 324 cases had prior hip fracture and 655 controls had no prior fracture. Using anonymized DXA hip scans, we measured FS and FRI. Separate multivariable logistic regression models were used to estimate odds ratios (ORs), c-statistics and their 95% confidence intervals (95% CIs) for the association of hip fracture with FS and FRI. RESULTS Increased hip fracture risk was associated with lower FS (OR per SD 1.36, 95% CI: 1.15, 1.62) and higher FRI (OR per SD 1.99, 95% CI: 1.63, 2.43) after adjusting for Fracture Risk Assessment Tool (FRAX) hip fracture probability computed with bone mineral density (BMD). The c-statistic for the model containing FS (0.69; 95% CI: 0.65, 0.72) was lower than the c-statistic for the model with FRI (0.77; 95% CI: 0.74, 0.80) or femoral neck BMD (0.74; 95% CI: 0.71, 0.77; all P<0.05). CONCLUSIONS FS and FRI were independently associated with hip fracture, but there were differences in performance characteristics.
Collapse
Affiliation(s)
- Shuman Yang
- Department of Epidemiology and Biostatistics, School of Public Health, Jilin University, Changchun, Jilin, China; Department of Community Health Sciences, University of Manitoba, Manitoba, Canada; Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Yunhua Luo
- Department of Mechanical Engineering, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Lang Yang
- Academic Unit of Bone Metabolism, Mellanby Centre for Bone Research University of Sheffield, Sheffield, UK; INSIGNEO Institute for in silico Medicine, University of Sheffield, Sheffield, UK
| | - Enrico Dall'Ara
- Academic Unit of Bone Metabolism, Mellanby Centre for Bone Research University of Sheffield, Sheffield, UK; INSIGNEO Institute for in silico Medicine, University of Sheffield, Sheffield, UK
| | - Richard Eastell
- Academic Unit of Bone Metabolism, Mellanby Centre for Bone Research University of Sheffield, Sheffield, UK; INSIGNEO Institute for in silico Medicine, University of Sheffield, Sheffield, UK
| | | | - Eugene V McCloskey
- Metabolic Bone Centre, Sorby Wing, Northern General Hospital, Sheffield, UK
| | - William D Leslie
- Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
| | - Lisa M Lix
- Department of Community Health Sciences, University of Manitoba, Manitoba, Canada
| |
Collapse
|