1
|
Martel DR, Callaghan JP, Mourtzakis M, Willett TL, Laing AC. Influence of test paradigm on loading dynamics during proximal femur fracture tests simulating sideways falls. J Mech Behav Biomed Mater 2024; 157:106631. [PMID: 38986216 DOI: 10.1016/j.jmbbm.2024.106631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 06/10/2024] [Accepted: 06/12/2024] [Indexed: 07/12/2024]
Abstract
Fall-related hip fractures are a serious public health issue in older adults. As most mechanistic hip fracture risk prediction models incorporate tissue tolerance, test methods that can accurately characterize the fracture force of the femur (and factors that influence it) are imperative. While bone possesses viscoelastic properties, experimental characterization of rate-dependencies has been inconsistent in the whole-femur literature. The goal of this study was to investigate the influence of experimental paradigm on loading rate and fracture force (both means and variability) during mechanical tests simulating lateral fall loadings on the proximal femur. Six pairs of matched femurs were split randomly between two test paradigms: a 'lower rate' materials testing system (MTS) with a constant displacement rate of 60 mm/s, and a hip impact test system (HIT) comprised of a custom-built vertical drop tower utilizing an impact velocity of 4 m/s. The loading rate was 88-fold higher for the HIT (mean (SD) = 2465.49 (807.38) kN/s) compared to the MTS (27.78 (10.03) kN/s) paradigm. However, no difference in fracture force was observed between test paradigms (mean (SD) = 4096.4 (1272.6) N for HIT, and 3641.3 (1285.8) N for MTS). Within-paradigm variability was not significantly different across paradigms for either loading rate or fracture force (coefficients of variation ranging from 0.311 to 0.361). Within each test paradigm, significant positive relationships were observed between loading rate and fracture force (HIT adjusted R2 = 0.833, p = 0.007; MTS adjusted R2 = 0.983, p < 0.0001). Overall, this study provides evidence that energy-based impact simulators can be a valid method to measure femoral bone strength in the context of fall-related hip fractures. This study motivates future research to characterize potential non-linear relationships between loading rate and fracture threshold at both macro and microscales.
Collapse
Affiliation(s)
- Daniel R Martel
- University of Waterloo, Department of Kinesiology and Health Sciences, Waterloo, ON, Canada
| | - Jack P Callaghan
- University of Waterloo, Department of Kinesiology and Health Sciences, Waterloo, ON, Canada
| | - Marina Mourtzakis
- University of Waterloo, Department of Kinesiology and Health Sciences, Waterloo, ON, Canada
| | - Thomas L Willett
- University of Waterloo, Department of Systems Design Engineering, Waterloo, ON, Canada
| | - Andrew C Laing
- University of Waterloo, Department of Kinesiology and Health Sciences, Waterloo, ON, Canada.
| |
Collapse
|
2
|
Snow T, Woolley W, Acevedo C, Kingstedt OT. Effect of in vitro ribosylation on the dynamic fracture behavior of mature bovine cortical bone. J Mech Behav Biomed Mater 2023; 148:106171. [PMID: 37890344 DOI: 10.1016/j.jmbbm.2023.106171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 05/01/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023]
Abstract
In this study, the fracture behavior of ribosylated bovine cortical bone is investigated under loading conditions simulating a fall event. Single edge notched specimens, separated into a control group (n = 11) and a ribosylated group (n = 8), were extracted from the mid-diaphysis of a single bovine femur harvested from a mature cow. A seven-day ribosylation process results in the accumulation of Advanced-Glycation End Products (AGEs) cross-links and AGE adducts. Specimens were subjected to symmetric three point bending (opening mode) and an impact velocity of 1.6 m/s using a drop tower. Near-crack displacement fields up to fracture initiation are determined from high-speed images post-processed using digital image correlation. A constrained over-deterministic least squares regression and orthotropic material linear elastic fracture mechanics theory are used to extract the in-plane critical stress intensity factors at fracture initiation (i.e., fracture initiation toughness values). Statistically significant differences were not observed when comparing the in-plane fracture initiation toughness values (p≥0.96) or energy release rate (p=0.90) between the control and seven-day ribosylated groups. The intrinsic variability of bone may require high sample numbers in order to achieve an adequately powered experiment when assessing dynamic fracture behavior. While there are no detectable differences due to the ribosylation treatment investigated, this is likely due to the limited sample sizes utilized.
Collapse
Affiliation(s)
- Tanner Snow
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - William Woolley
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, 84112, USA; Department of Mechanical and Aerospace Engineering, University of California San Diego, San Diego, CA, 92093, USA
| | - Claire Acevedo
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, 84112, USA; Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, 84112, USA; Department of Mechanical and Aerospace Engineering, University of California San Diego, San Diego, CA, 92093, USA.
| | - Owen T Kingstedt
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT, 84112, USA.
| |
Collapse
|
3
|
Effects of hip muscle activation on the stiffness and energy absorption of the trochanteric soft tissue during impact in sideways falls. J Mech Behav Biomed Mater 2023; 138:105622. [PMID: 36538838 DOI: 10.1016/j.jmbbm.2022.105622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 12/06/2022] [Accepted: 12/11/2022] [Indexed: 12/23/2022]
Abstract
The trochanteric soft tissue attenuates impact force or absorbs impact energy during a fall on the hip (thereby helps to reduce a risk of hip fracture). While the benefits should be affected by contractions of muscles spanning the hip joint, no information is available to date. We examined how the stiffness (force attenuation capacity) and energy absorption of the trochanteric soft tissue were affected by hip muscle activation during a fall. Thirteen healthy young individuals (5 males, 8 females) participated in the pelvis release experiment. Falling trials were acquired with three muscle contraction conditions: 0-20% ("relaxed"), 20-50% ("moderate"), and 60-100% ("maximal") of the maximal voluntary isometric contraction of the gluteus medius muscle. During trials, we measured real-time force and deformation behaviour of the trochanteric soft tissue. Outcome variables included the stiffness and energy absorption of the soft tissue. The stiffness and energy absorption ranged from 56.1 to 446.9 kN/m, and from 0.15 to 2.26 J, respectively. The stiffness value increased with muscle contraction, and 59% greater in "maximal" than "relaxed" condition (232.2 (SD = 121.4) versus 146.1 (SD = 49.9)). However, energy absorption decreased with muscle contraction, and 58.9% greater in "relaxed" than "maximal" condition (0.89 (SD = 0.63) versus 0.56 (SD = 0.41)). Our results provide insights on biomechanics of the trochanteric soft tissue ("natural" padding device) during impact stage of a fall, suggesting that soft tissues' protective benefits are largely affected by the level of muscle contraction.
Collapse
|
4
|
Aldieri A, Terzini M, Audenino AL, Bignardi C, Paggiosi M, Eastell R, Viceconti M, Bhattacharya P. Personalised 3D Assessment of Trochanteric Soft Tissues Improves HIP Fracture Classification Accuracy. Ann Biomed Eng 2022; 50:303-313. [PMID: 35103867 PMCID: PMC8847196 DOI: 10.1007/s10439-022-02924-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 01/19/2022] [Indexed: 01/09/2023]
Abstract
Passive soft tissues surrounding the trochanteric region attenuate fall impact forces and thereby control hip fracture risk. The degree of attenuation is related to Soft Tissue Thickness (STT). STT at the neutral hip impact orientation, estimated using a regression relation in body mass index (BMI), was previously shown to influence the current absolute risk of hip fracture (ARF0) and its fracture classification accuracy. The present study investigates whether fracture classification using ARF0 improves when STT is determined from the subject’s Computed-Tomography (CT) scans (i.e. personalised) in an orientation-specific (i.e. 3D) manner. STT is calculated as the shortest distance along any impact orientation between a semi-automatically segmented femur surface and an automatically segmented soft tissue/air boundary. For any subject, STT along any of the 33 impact orientations analysed always exceeds the value estimated using BMI. Accuracy of fracture classification using ARF0 improves when using personalised 3D STT estimates (AUC = 0.87) instead of the BMI-based STT estimate (AUC = 0.85). The improvement is smaller (AUC = 0.86) when orientation-specificity of CT-based STT is suppressed and is nil when personalisation is suppressed instead. Thus, fracture classification using ARF0 improves when CT is used to personalise STT estimates and improves further when, in addition, the estimates are orientation specific.
Collapse
Affiliation(s)
- Alessandra Aldieri
- PolitoBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy.,Department of Industrial Engineering, Alma Mater Studiorum - University of Bologna, Bologna, Italy.,Laboratorio di Tecnologia Medica, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Mara Terzini
- PolitoBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Alberto L Audenino
- PolitoBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Cristina Bignardi
- PolitoBIOMed Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Margaret Paggiosi
- INSIGNEO Institute for In Silico Medicine, University of Sheffield, Pam Liversidge Building, Sheffield, S1 3JD, UK.,Academic Unit of Bone Metabolism, University of Sheffield, Sheffield, UK
| | - Richard Eastell
- INSIGNEO Institute for In Silico Medicine, University of Sheffield, Pam Liversidge Building, Sheffield, S1 3JD, UK.,Academic Unit of Bone Metabolism, University of Sheffield, Sheffield, UK
| | - Marco Viceconti
- Department of Industrial Engineering, Alma Mater Studiorum - University of Bologna, Bologna, Italy.,Laboratorio di Tecnologia Medica, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Pinaki Bhattacharya
- INSIGNEO Institute for In Silico Medicine, University of Sheffield, Pam Liversidge Building, Sheffield, S1 3JD, UK. .,Department of Mechanical Engineering, University of Sheffield, Sheffield, UK.
| |
Collapse
|
5
|
The Effects of Body Position on Trochanteric Soft Tissue Thickness-Implications for Predictions of Impact Force and Hip Fracture Risk During Lateral Falls. J Appl Biomech 2021; 37:556-564. [PMID: 34784585 DOI: 10.1123/jab.2020-0156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 01/28/2021] [Accepted: 09/16/2021] [Indexed: 11/18/2022]
Abstract
Trochanteric soft tissue thickness (TSTT) is a protective factor against fall-related hip fractures. This study's objectives were to determine: (1) the influence of body posture on TSTT and (2) the downstream effects of TSTT on biomechanical model predictions of fall-related impact force (Ffemur) and hip fracture factor of risk. Ultrasound was used to measure TSTT in 45 community-dwelling older adults in standing, supine, and side-lying positions with hip rotation angles of -25°, 0°, and 25°. Supine TSTT (mean [SD] = 5.57 [2.8] cm) was 29% and 69% greater than in standing and side-lying positions, respectively. The Ffemur based on supine TSTT (3380 [2017] N) was 19% lower than the standing position (4173 [1764] N) and 31% lower than the side-lying position (4908 [1524] N). As factor of risk was directly influenced by Ffemur, the relative effects on fracture risk were similar. While less pronounced (<10%), the effects of hip rotation angle were consistent across TSTT, Ffemur, and factor of risk. Based on the sensitivity of impact models to TSTT, these results highlight the need for a standardized TSTT measurement approach. In addition, the consistent influence of hip rotation on TSTT (and downstream model predictions) support its importance as a factor that may influence fall-related hip fracture risk.
Collapse
|
6
|
Komisar V, Robinovitch SN. The Role of Fall Biomechanics in the Cause and Prevention of Bone Fractures in Older Adults. Curr Osteoporos Rep 2021; 19:381-390. [PMID: 34105101 DOI: 10.1007/s11914-021-00685-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/22/2021] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW Adults over age 65 experience the highest rates of bone fracture, and 90% of fractures in older adults are caused by falls from standing height or lower. Advances in fracture prevention rely on our ability to prevent falls, reduce the severity of falls, and enhance the resistance of bone to trauma. To help guide these efforts, we need improved understanding on the types of falls that cause fractures. RECENT FINDINGS In this review, we describe recent evidence on how the mechanics of falls in older adults influence the risk for fractures to the hip, wrist, vertebrae, and humerus. We discuss how fracture risk depends on fall height, fall direction, and landing configuration. We also review the benefits of exercise, wearable protective gear, and environmental modifications in preventing fractures in older adults. Our findings highlight promising new directions in fracture prevention, and the need for collaboration between the bone and falls research communities to implement proven strategies and generate new solutions.
Collapse
Affiliation(s)
- Vicki Komisar
- School of Engineering, The University of British Columbia, Kelowna, BC, Canada
| | - Stephen Neil Robinovitch
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
- School of Engineering Science, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A 1S6, Canada.
| |
Collapse
|
7
|
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
|