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Szabo NE, Johnson JE, Brouillette MJ, Goetz JE. Implications of using simplified finite element meshes to identify material parameters of articular cartilage. Med Eng Phys 2024; 131:104200. [PMID: 39284645 DOI: 10.1016/j.medengphy.2024.104200] [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: 11/30/2023] [Revised: 06/10/2024] [Accepted: 06/27/2024] [Indexed: 09/19/2024]
Abstract
The objective of this work was to determine the effects of using simplified finite element (FE) mesh geometry in the process of performing reverse iterative fitting to estimate cartilage material parameters from in situ indentation testing. Six bovine tibial osteochondral explants were indented with sequential 5 % step-strains followed by a 600 s hold while relaxation force was measured. Three sets of porous viscohyperelastic material parameters were estimated for each specimen using reverse iterative fitting of the indentation test with (1) 2D axisymmetric, (2) 3D idealized, and (3) 3D specimen-specific FE meshes. Variable material parameters were identified using the three different meshes, and there were no systematic differences, correlation to basic geometric features, nor distinct patterns of variation based on the type of mesh used. Implementing the three material parameter sets in a separate 3D FE model of 40 % compressive strain produced differences in von Mises stresses and pore pressures up to 25 % and 50 %, respectively. Accurate material parameters are crucial in any FE model, and parameter differences influenced by idealized assumptions in initial material property determination have the potential to alter subsequent FE models in unpredictable ways and hinder the interpretation of their results.
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Affiliation(s)
- Nicole E Szabo
- Department of Orthopedics and Rehabilitation, University of Iowa, Iowa City, IA, 52242, USA; Department of Biomedical Engineering, University of Iowa, Iowa City, IA, 52242, USA
| | - Joshua E Johnson
- Department of Orthopedics and Rehabilitation, University of Iowa, Iowa City, IA, 52242, USA
| | - Marc J Brouillette
- Department of Orthopedics and Rehabilitation, University of Iowa, Iowa City, IA, 52242, USA
| | - Jessica E Goetz
- Department of Orthopedics and Rehabilitation, University of Iowa, Iowa City, IA, 52242, USA; Department of Biomedical Engineering, University of Iowa, Iowa City, IA, 52242, USA.
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Tachibana T, Katagiri H, Matsuda J, Ozeki N, Watanabe T, Sekiya I, Jinno T. Biomechanical analysis of load distribution in porcine hip joints at different acetabular coverages. BMC Musculoskelet Disord 2024; 25:576. [PMID: 39049016 PMCID: PMC11267855 DOI: 10.1186/s12891-024-07701-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 07/17/2024] [Indexed: 07/27/2024] Open
Abstract
BACKGROUND Developmental dysplasia of the hip causes secondary osteoarthritis. Finite element analysis suggests high hip joint contact pressure in patients with hip dysplasia and a reduction in contact pressure after periacetabular osteotomy. However, few biomechanical studies have examined the load distribution in the hip joint. This study aimed to investigate the biomechanical properties of load distribution in porcine hip joints at different acetabular coverages. METHODS Six porcine hip joints were analyzed using three models: 1) neutral coverage, 2) 15° under-coverage (defined as dysplasia model), and 3) 15° over-coverage created by varying the acetabular coverage. The load distribution was assessed using a pressure-mapping sensor system after applying a loading force of 100 N to the hip joint. RESULTS In the dysplasia model, the load was concentrated at the acetabular rim; in the neutral and over-coverage models, it was dispersed. The average contact pressure was significantly higher in the dysplasia model than in the neutral coverage model ([0.42 vs. 0.3 MPa]; p = 0.004). The contact area was significantly smaller in the dysplasia model than in the neutral coverage model ([250.7 vs. 345.0 mm2]; p = 0.004). No significant differences were observed in contact pressure or area between the neutral and over-coverage models. CONCLUSIONS Insufficient acetabular coverage in the dysplasia model demonstrated higher contact pressure and smaller contact area than the neutral model. Conversely, the contact pressure and area in the over-coverage model did not differ significantly from those in the normal model. Therefore, surgeons should note that acetabular coverage overcorrection has limited effect; normalization is crucial during periacetabular osteotomy.
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Affiliation(s)
- Tetsuya Tachibana
- Department of Orthopedic Surgery, Dokkyo Medical University, Saitama Medical Center, 2-1-50 Minami-Koshigaya, Koshigaya City, Saitama, 343-8555, Japan
- Department of Joint Surgery and Sports Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Hiroki Katagiri
- Department of Orthopedic Surgery, Dokkyo Medical University, Saitama Medical Center, 2-1-50 Minami-Koshigaya, Koshigaya City, Saitama, 343-8555, Japan.
- Department of Joint Surgery and Sports Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
| | - Junpei Matsuda
- Center for Stem Cell and Regenerative Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Nobutake Ozeki
- Center for Stem Cell and Regenerative Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Toshifumi Watanabe
- Department of Orthopedic Surgery, Dokkyo Medical University, Saitama Medical Center, 2-1-50 Minami-Koshigaya, Koshigaya City, Saitama, 343-8555, Japan
| | - Ichiro Sekiya
- Center for Stem Cell and Regenerative Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Tetsuya Jinno
- Department of Orthopedic Surgery, Dokkyo Medical University, Saitama Medical Center, 2-1-50 Minami-Koshigaya, Koshigaya City, Saitama, 343-8555, Japan
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Berni M, Marchiori G, Baleani M, Giavaresi G, Lopomo NF. Biomechanics of the Human Osteochondral Unit: A Systematic Review. MATERIALS (BASEL, SWITZERLAND) 2024; 17:1698. [PMID: 38612211 PMCID: PMC11012636 DOI: 10.3390/ma17071698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 03/17/2024] [Accepted: 03/26/2024] [Indexed: 04/14/2024]
Abstract
The damping system ensured by the osteochondral (OC) unit is essential to deploy the forces generated within load-bearing joints during locomotion, allowing furthermore low-friction sliding motion between bone segments. The OC unit is a multi-layer structure including articular cartilage, as well as subchondral and trabecular bone. The interplay between the OC tissues is essential in maintaining the joint functionality; altered loading patterns can trigger biological processes that could lead to degenerative joint diseases like osteoarthritis. Currently, no effective treatments are available to avoid degeneration beyond tissues' recovery capabilities. A thorough comprehension on the mechanical behaviour of the OC unit is essential to (i) soundly elucidate its overall response to intra-articular loads for developing diagnostic tools capable of detecting non-physiological strain levels, (ii) properly evaluate the efficacy of innovative treatments in restoring physiological strain levels, and (iii) optimize regenerative medicine approaches as potential and less-invasive alternatives to arthroplasty when irreversible damage has occurred. Therefore, the leading aim of this review was to provide an overview of the state-of-the-art-up to 2022-about the mechanical behaviour of the OC unit. A systematic search is performed, according to PRISMA standards, by focusing on studies that experimentally assess the human lower-limb joints' OC tissues. A multi-criteria decision-making method is proposed to quantitatively evaluate eligible studies, in order to highlight only the insights retrieved through sound and robust approaches. This review revealed that studies on human lower limbs are focusing on the knee and articular cartilage, while hip and trabecular bone studies are declining, and the ankle and subchondral bone are poorly investigated. Compression and indentation are the most common experimental techniques studying the mechanical behaviour of the OC tissues, with indentation also being able to provide information at the micro- and nanoscales. While a certain comparability among studies was highlighted, none of the identified testing protocols are currently recognised as standard for any of the OC tissues. The fibril-network-reinforced poro-viscoelastic constitutive model has become common for describing the response of the articular cartilage, while the models describing the mechanical behaviour of mineralised tissues are usually simpler (i.e., linear elastic, elasto-plastic). Most advanced studies have tested and modelled multiple tissues of the same OC unit but have done so individually rather than through integrated approaches. Therefore, efforts should be made in simultaneously evaluating the comprehensive response of the OC unit to intra-articular loads and the interplay between the OC tissues. In this regard, a multidisciplinary approach combining complementary techniques, e.g., full-field imaging, mechanical testing, and computational approaches, should be implemented and validated. Furthermore, the next challenge entails transferring this assessment to a non-invasive approach, allowing its application in vivo, in order to increase its diagnostic and prognostic potential.
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Affiliation(s)
- Matteo Berni
- Laboratorio di Tecnologia Medica, IRCCS Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy; (M.B.); (M.B.)
| | - Gregorio Marchiori
- Scienze e Tecnologie Chirurgiche, IRCCS Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy;
| | - Massimiliano Baleani
- Laboratorio di Tecnologia Medica, IRCCS Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy; (M.B.); (M.B.)
| | - Gianluca Giavaresi
- Scienze e Tecnologie Chirurgiche, IRCCS Istituto Ortopedico Rizzoli, Via di Barbiano 1/10, 40136 Bologna, Italy;
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Kakavand R, Palizi M, Tahghighi P, Ahmadi R, Gianchandani N, Adeeb S, Souza R, Edwards WB, Komeili A. Integration of Swin UNETR and statistical shape modeling for a semi-automated segmentation of the knee and biomechanical modeling of articular cartilage. Sci Rep 2024; 14:2748. [PMID: 38302524 PMCID: PMC10834430 DOI: 10.1038/s41598-024-52548-9] [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: 10/03/2023] [Accepted: 01/19/2024] [Indexed: 02/03/2024] Open
Abstract
Simulation studies, such as finite element (FE) modeling, provide insight into knee joint mechanics without patient involvement. Generic FE models mimic the biomechanical behavior of the tissue, but overlook variations in geometry, loading, and material properties of a population. Conversely, subject-specific models include these factors, resulting in enhanced predictive precision, but are laborious and time intensive. The present study aimed to enhance subject-specific knee joint FE modeling by incorporating a semi-automated segmentation algorithm using a 3D Swin UNETR for an initial segmentation of the femur and tibia, followed by a statistical shape model (SSM) adjustment to improve surface roughness and continuity. For comparison, a manual FE model was developed through manual segmentation (i.e., the de-facto standard approach). Both FE models were subjected to gait loading and the predicted mechanical response was compared. The semi-automated segmentation achieved a Dice similarity coefficient (DSC) of over 98% for both the femur and tibia. Hausdorff distance (mm) between the semi-automated and manual segmentation was 1.4 mm. The mechanical results (max principal stress and strain, fluid pressure, fibril strain, and contact area) showed no significant differences between the manual and semi-automated FE models, indicating the effectiveness of the proposed semi-automated segmentation in creating accurate knee joint FE models. We have made our semi-automated models publicly accessible to support and facilitate biomechanical modeling and medical image segmentation efforts ( https://data.mendeley.com/datasets/k5hdc9cz7w/1 ).
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Affiliation(s)
- Reza Kakavand
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, CCIT 216, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Mehrdad Palizi
- Civil and Environmental Engineering Department, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Peyman Tahghighi
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, CCIT 216, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Reza Ahmadi
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, CCIT 216, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Neha Gianchandani
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, CCIT 216, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Samer Adeeb
- Civil and Environmental Engineering Department, Faculty of Engineering, University of Alberta, Edmonton, Canada
| | - Roberto Souza
- Department of Electrical and Software Engineering, Schulich School of Engineering, University of Calgary, Calgary, Canada
- Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, Canada
| | - W Brent Edwards
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, CCIT 216, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Canada
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Canada
| | - Amin Komeili
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, CCIT 216, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
- McCaig Institute for Bone and Joint Health, University of Calgary, Calgary, Canada.
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Canada.
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Guo Y, Zhao H, Wang F, Xu H, Liu X, Hu T, Wu D. Telomere length as a marker of changes in body composition and fractures-an analysis of data from the NHANES 2001-2002. Front Immunol 2023; 14:1181544. [PMID: 37744360 PMCID: PMC10514483 DOI: 10.3389/fimmu.2023.1181544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 08/23/2023] [Indexed: 09/26/2023] Open
Abstract
Purpose There has been an association between changes in body composition, fracture incidence, and age in previous studies. Telomere length (TL) has been proposed as a biomarker of aging. However, the relationship between body composition, fractures, and TL has rarely been studied. Therefore, this study aimed to investigate the correlation between TL and body composition and fractures.Patients and methods: 20950 participants from the 2001-2002 National Health and Nutrition Examination Survey (NHANES) were included in the final analysis. In NHANES, body compositions were measured with DXA, and TL was determined with quantitative PCR. Correlation analysis of TL and body composition was conducted using multivariate weighted linear regression and logistic regression models. Results The results showed that TL positively correlated with bone mineral density (BMD) and bone mineral content (BMC) in most body parts. However, BMD and BMC were negatively connected with TL in the upper limbs and skull. Fat content was negatively associated with TL, while muscle content was positively linked to TL. In addition, TL's trend analysis results were consistent with the regression model when transformed from a continuous to a classified variable. An increase in TL was associated with a higher incidence of wrist fractures, while a decrease in spine fractures. The above correlation also has a certain degree of sex specificity. Conclusion Our study indicate that TL is associated with body composition as well as fractures, but further research is needed to confirm these contrasting associations in the skull, upper limbs, and wrists.
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Affiliation(s)
| | | | | | | | | | - Tao Hu
- Department of Spine Surgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Desheng Wu
- Department of Spine Surgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
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Lewis CL, Uemura K, Atkins PR, Lenz AL, Fiorentino NM, Aoki SK, Anderson AE. Patients with cam-type femoroacetabular impingement demonstrate increased change in bone-to-bone distance during walking: A dual fluoroscopy study. J Orthop Res 2023; 41:161-169. [PMID: 35325481 PMCID: PMC9508282 DOI: 10.1002/jor.25332] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/24/2022] [Accepted: 03/22/2022] [Indexed: 02/07/2023]
Abstract
Cam-type femoroacetabular impingement (FAI) syndrome is a painful, structural hip disorder. Herein, we investigated hip joint mechanics through in vivo, dynamic measurement of the bone-to-bone distance between the femoral head and acetabulum in patients with cam FAI syndrome and morphologically screened controls. We hypothesized that individuals with cam FAI syndrome would have larger changes in bone-to-bone distance compared to the control group, which we would interpret as altered joint mechanics as signified by greater movement of the femoral head as it articulates within the acetabulum. Seven patients with cam FAI syndrome and 11 asymptomatic individuals with typical morphology underwent dual fluoroscopy imaging during level and inclined walking (upward slope). The change in bone-to-bone distance between femoral and acetabular bone surfaces was evaluated for five anatomical regions of the acetabulum at each timepoint of gait. Linear regression analysis of the bone-to-bone distance considered two within-subject factors (activity and region) and one between-subjects factor (group). Across activities, the change in minimum bone-to-bone distance was 1.38-2.54 mm for the cam FAI group and 1.16-1.84 mm for controls. In all regions except the anterior-superior region, the change in bone-to-bone distance was larger in the cam group than the control group (p ≤ 0.024). An effect of activity was detected only in the posterior-superior region where larger changes were noted during level walking than incline walking. Statement of clinical significance: Patients with cam FAI syndrome exhibit altered hip joint mechanics during the low-demand activity of walking; these alterations could affect load transmission, and contribute to pain, tissue damage, and osteoarthritis.
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Affiliation(s)
- Cara L Lewis
- Department of Physical Therapy and Athletic Training, Boston University, Boston, Massachusetts, USA
| | - Keisuke Uemura
- Department of Orthopaedics, University of Utah, Salt Lake City, Utah, USA
| | - Penny R Atkins
- Department of Orthopaedics, University of Utah, Salt Lake City, Utah, USA
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, Utah, USA
| | - Amy L Lenz
- Department of Orthopaedics, University of Utah, Salt Lake City, Utah, USA
| | - Niccolo M Fiorentino
- Department of Mechanical Engineering, University of Vermont, Burlington, Vermont, USA
| | - Stephen K Aoki
- Department of Orthopaedics, University of Utah, Salt Lake City, Utah, USA
| | - Andrew E Anderson
- Department of Orthopaedics, University of Utah, Salt Lake City, Utah, USA
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, Utah, USA
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah, USA
- Department of Physical Therapy, University of Utah, Salt Lake City, Utah, USA
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Schuring LL, Mozingo JD, Lenz AL, Uemura K, Atkins PR, Fiorentino NM, Aoki SK, Peters CL, Anderson AE. Acetabular labrum and cartilage contact mechanics during pivoting and walking tasks in individuals with cam femoroacetabular impingement syndrome. J Biomech 2023; 146:111424. [PMID: 36603366 PMCID: PMC9869780 DOI: 10.1016/j.jbiomech.2022.111424] [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: 02/24/2022] [Revised: 12/01/2022] [Accepted: 12/23/2022] [Indexed: 12/25/2022]
Abstract
Femoroacetabular impingement syndrome (FAIS) is a motion-related pathology of the hip characterized by pain, morphological abnormalities of the proximal femur, and an elevated risk of joint deterioration and hip osteoarthritis. Activities that require deep flexion are understood to induce impingement in cam FAIS patients, however, less demanding activities such as walking and pivoting may induce pain as well as alterations in kinematics and joint stability. Still, the paucity of quantitative descriptions of cam FAIS has hindered understanding underlying hip joint mechanics during such activities. Previous in silico studies have employed generalized model geometry or kinematics to simulate impingement between the femur and acetabulum, which may not accurately capture the interplay between morphology and motion. In this study, we utilized models with participant-specific bone and articular soft tissue anatomy and kinematics measured by dual-fluoroscopy to compare hip contact mechanics of cam FAIS patients to controls during four activities of daily living (internal/external pivoting and level/incline walking). Averaged across the gait cycle during incline walking, patients displayed increased strain in the anterior joint (labrum strain: p-value = 0.038, patients: 11.7 ± 6.7 %, controls: 5.0 ± 3.6 %; cartilage strain: p-value = 0.029, patients: 9.1 ± 3.3 %, controls: 4.2 ± 2.3). Patients also exhibited increased average anterior cartilage strains during external pivoting (p-value = 0.039; patients: 13.0 ± 9.2 %, controls: 3.9 ± 3.2 %]). No significant differences between patient and control contact area and strain were found for level walking and internal pivoting. Our study provides new insights into the biomechanics of cam FAIS, including spatiotemporal hip joint contact mechanics during activities of daily living.
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Affiliation(s)
- Lindsay L Schuring
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA; Department of Orthopaedics, University of Utah, Salt Lake City, UT 84108, USA
| | - Joseph D Mozingo
- Department of Orthopaedics, University of Utah, Salt Lake City, UT 84108, USA
| | - Amy L Lenz
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA; Department of Orthopaedics, University of Utah, Salt Lake City, UT 84108, USA; Department of Mechanical Engineering, University of Utah, Salt Lake City, UT 84112, USA
| | - Keisuke Uemura
- Department of Orthopaedics, University of Utah, Salt Lake City, UT 84108, USA
| | - Penny R Atkins
- Department of Orthopaedics, University of Utah, Salt Lake City, UT 84108, USA; Scientific Computing and Imaging Institute, Salt Lake City, UT 84112, USA
| | - Niccolo M Fiorentino
- Mechanical Engineering Department, University of Vermont, Burlington, VT 05405, USA
| | - Stephen K Aoki
- Department of Orthopaedics, University of Utah, Salt Lake City, UT 84108, USA
| | | | - Andrew E Anderson
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT 84112, USA; Department of Orthopaedics, University of Utah, Salt Lake City, UT 84108, USA; Scientific Computing and Imaging Institute, Salt Lake City, UT 84112, USA; Department of Physical Therapy, University of Utah, Salt Lake City, UT 84108, USA.
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He J, Wine I, Wu K, Sevick J, Laouar L, Jomha NM, Westover L. Effect of vitrification on mechanical properties of porcine articular cartilage. Proc Inst Mech Eng H 2022; 236:1521-1527. [PMID: 36169308 PMCID: PMC9574425 DOI: 10.1177/09544119221122066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 08/08/2022] [Indexed: 02/05/2023]
Abstract
Articular cartilage (AC) injuries do not heal primarily and large lesions progress to degenerative osteoarthritis. Osteochondral allograft transplantation is an effective surgical treatment but is limited by the lack of donor tissue availability. Fresh allografts can be stored hypothermically up to 28-45 days after which the tissue is no longer viable for transplantation. Vitrification is a method of cryopreservation with the potential to extend the storage time of AC. A specific protocol has been demonstrated to preserve high chondrocyte viability; however, its effect on various mechanical properties of the extracellular matrix (ECM) remains unknown and is the focus of this initial study. Porcine AC was subject to a defined vitrification protocol, using fresh and frozen samples as positive and negative controls, respectively; n = 20 for all three groups. Unconfined compression testing was used to assess mechanical properties of the tissue under rapid load, stress relaxation, and equilibrium conditions. The stress relaxation time constants (modeled with a 2-term Prony series) τ1 and τ2 were significantly lower for frozen (p = 0.014, p < 0.001) and vitrified (p = 0.009, p = 0.003) tissue compared to fresh, with no differences between frozen and vitrified samples (p = 0.848 and 0.105 for τ1 and τ2, respectively). These values indicate that frozen and vitrified samples relaxed more rapidly than fresh, which may suggest altered matrix composition and permeability post-treatment. These results represent the initial study in our experimental path to evaluate differences in mechanical properties of vitrified tissues.
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Affiliation(s)
- Jenny He
- Department of Surgery, University of Alberta, Edmonton, AB,
Canada
| | - Itai Wine
- Department of Civil and Environmental Engineering, University of
Alberta, Edmonton, AB, Canada
| | - Kezhou Wu
- Department of Surgery, University of Alberta, Edmonton, AB,
Canada
- Department of Orthopedic Surgery, First Affiliated Hospital, Shantou
University Medical College, Shantou, Guangdong, China
| | - Johnathan Sevick
- Department of Surgery, University of Alberta, Edmonton, AB,
Canada
| | - Leila Laouar
- Department of Surgery, University of Alberta, Edmonton, AB,
Canada
| | - Nadr M Jomha
- Department of Surgery, University of Alberta, Edmonton, AB,
Canada
| | - Lindsey Westover
- Department of Mechanical Engineering, University of Alberta,
Edmonton, AB, Canada
- Lindsey Westover, Department of Mechanical
Engineering, University of Alberta, 9211 116 Street NW, 10-371 D-ICE Building,
Edmonton, AB T6G 1H9, Canada.
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Morgan O, Hillstrom H, Bitar R, Sturnick D, Koff MF, Ellis S, Deland J, Hillstrom R. Finite Element Modelling of Planus and Rectus Foot Types for the Study of First Metatarsophalangeal and First Metatarsocuneiform Joint Contact Mechanics. J Biomech Eng 2022; 144:1135615. [PMID: 35147162 DOI: 10.1115/1.4053791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Indexed: 11/08/2022]
Abstract
Evaluating the contact mechanics of human joints is an important element in understanding the pathomechanics of orthopaedic diseases. Although physical testing is essential in the evaluation process, reliable computational models can augment these experiments by non-invasive predictions of biomechanical or surgical variables. The objective of this study was to perform verification of a framework for developing a medial forefoot finite element. Verification was conducted by comparing computational predictions to experimental measurements of first metatarsophalangeal and first metatarsocuneiform joint contact mechanics. A custom-built force-controlled cadaveric test-rig was used to derive measurements of contact pressure, force, and area. A quasi-static finite element was developed and driven under the same boundary and loading conditions. Calibration of cartilage moduli and mesh sensitivity analyses were performed. Mean errors in contact pressures, forces, and areas were 24%, 4%, and 40% at the first metatarsophalangeal joint and 23%, 12%, and 19% at the first Metatarsocuneiform joint, respectively. Verification of a medial forefoot finite element model development framework was presented and found to be within 30% for contact pressure and contact force of both joints. This study presents a method to verify and simulate realistic physiological loading to investigate orthopaedic diseases of the medial forefoot.
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Affiliation(s)
- Oliver Morgan
- Faculty of Science and Engineering, Anglia Ruskin University, Chelmsford, Essex, UK
| | - Howard Hillstrom
- Leon Root, MD Motion Analysis Laboratory, Hospital for Special Surgery, New York, NY, USA
| | - Rogerio Bitar
- Department of Biomechanics, Hospital for Special Surgery, New York, NY, USA
| | - Daniel Sturnick
- Department of Biomechanics, Hospital for Special Surgery, New York, NY, USA
| | - Matthew F Koff
- Department of Radiology and Imaging, Hospital for Special Surgery, New York, New York, USA
| | - Scott Ellis
- Department of Orthopedics, Foot and Ankle Division, Hospital for Special Surgery, New York, NY, USA
| | - Jonathan Deland
- Department of Orthopedics, Foot and Ankle Division, Hospital for Special Surgery, New York, NY, USA
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Dwivedi KK, Lakhani P, Kumar S, Kumar N. A hyperelastic model to capture the mechanical behaviour and histological aspects of the soft tissues. J Mech Behav Biomed Mater 2021; 126:105013. [PMID: 34920323 DOI: 10.1016/j.jmbbm.2021.105013] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 11/10/2021] [Accepted: 11/27/2021] [Indexed: 11/19/2022]
Abstract
It is well established that the soft connective tissues show a nonlinear elastic response that comes from their microstructural arrangement. Tissues' microstructure alters with various physiological conditions and may affect their mechanical responses. Therefore, the accurate prediction of tissue's mechanical response is crucial for clinical diagnosis and treatments. Thus, a physically motivated and mathematically simplified model is required for the accurate prediction of tissues' mechanical and structural responses. This study explored the 'Exp-Ln' hyperelastic model (Khajehsaeid et al., 2013) to capture soft tissues' mechanical and histological behaviour. In this work, uniaxial tensile test data for the belly and back pig skin were extracted from the experiments performed in our laboratory, whereas uniaxial test data for other soft tissues (human skin, tendon, ligament, and aorta) were extracted from the literature. The 'Exp-Ln; and other hyperelastic models (e.g. Money Rivlin, Ogden, Yeoh, and Gent models) were fitted with these experimental data, and obtained results were compared between the models. These results show that the 'Exp-Ln' model could capture the mechanical behaviour of soft tissues more accurately than other hyperelastic models. This model was also found numerically stable for all modes and ranges of deformation. This study also investigated the link between 'Exp-Ln' material parameters and tissue's histological parameters. The histological parameters such as collagen content, fibre free length, crosslink density, and collagen arrangement were measured using staining and ATR-FTIR techniques. The material parameters were found statistically correlated with the histological parameters. Further, 'Exp-Ln' model was implemented in ABAQUS through the VUMAT subroutine, where the mechanical behaviour of various soft tissues was simulated for different modes of deformation. The finite element analysis results obtained using the 'Exp-Ln' model agreed with the experiments and were more accurate than other hyperelastic models. Overall, these results demonstrate the capability of 'Exp-Ln' model to predict the mechanical and structural responses of the soft tissues.
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Affiliation(s)
- Krashn Kr Dwivedi
- Department of Biomedical Engineering, Indian Institute of Technology Ropar, India
| | - Piyush Lakhani
- Department of Mechanical Engineering, Indian Institute of Technology Ropar, India
| | - Sachin Kumar
- Department of Mechanical Engineering, Indian Institute of Technology Ropar, India
| | - Navin Kumar
- Department of Biomedical Engineering, Indian Institute of Technology Ropar, India; Department of Mechanical Engineering, Indian Institute of Technology Ropar, India.
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Shao LT, Gou Y, Fang JK, Hu YP, Lian QQ, Yang Z, Zhang YY, Wang YD, Tian FM, Zhang L. The Protective Effects of Parathyroid Hormone (1-34) on Cartilage and Subchondral Bone Through Down-Regulating JAK2/STAT3 and WNT5A/ROR2 in a Collagenase-Induced Osteoarthritis Mouse Model. Orthop Surg 2021; 13:1662-1672. [PMID: 34105258 PMCID: PMC8313171 DOI: 10.1111/os.13019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 03/13/2021] [Accepted: 03/18/2021] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVE To assess the effects of PTH (1-34) on bone and cartilage metabolism in a collagenase-induced mouse model of osteoarthritis (OA) and examine whether PTH (1-34) affects the expression of JAK2/STAT3 and WNT5A/ROR2 in this process. METHODS Eighteen 12-week-old male C57Bl/6 mice were randomly assigned into three groups as follows: sham group (Group A), the collagenase + saline injection group (Group B), and the collagenase + PTH (1-34) treatment group (Group C). Collagenase was injected (intra-articular) into the knee joint of Group B and C. The PTH (1-34)-treatment was started at 6 weeks after the operation and lasted for 6 weeks. Cartilage pathology was evaluated by gross visual, histological, and immunohistochemical assessments. Subchondral bone was evaluated by microcomputed tomography (micro-CT) and immunohistochemical analyses. RESULTS The OARSI macroscopic and microscopic scores of Group B were higher than those of Group A (P = 0.026; P = 0.002, respectively). Group C showed statistically significant differences in macroscopic and microscopic scores from Group B (P = 0.041; P = 0.008, respectively). The results showed that the Col-II and AGG expression levels in the cartilage tissue were significantly lower in Group B than Group A (P < 0.001; P = 0.008, respectively). The Col-II and AGG expression levels were significantly higher in Group C than Group B (P = 0.009; P = 0.014, respectively). MMP-13, ADAMTS-4, Caspase-3, P53, and Bax expression levels were significantly higher in Group B than the Group A (P < 0.001; P < 0.001; P = 0.04; P < 0.001; P = 0.005, respectively); however, the cartilage tissue in Group C showed significantly less ADAMTS-4, MMP-13, Caspase-3, P53, and Bax expression than Group B (P < 0.001, P < 0.001, P = 0.044; P = 0.002; P = 0.005, respectively). Over-expressed JAK2/STAT3 and WNT5A/ROR2 were observed in both cartilage and subchondral bone in this model; however, these changes were prevented by PTH (1-34) treatment. These parameters (bone mineral density, bone volume ratio, trabecular bone pattern factor, and structure model index) of micro-CT indicated subchondral bone loss and architecture changes in Group B, but improvements in these parameters in Group C. CONCLUSIONS PTH (1-34) exhibits protective effects on both cartilage and subchondral bone in a collagenase-induced OA mouse model, and it may be involved in down-regulating the expression of JAK2/STAT3 and WNT5A/ROR2.
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Affiliation(s)
- Li-Tao Shao
- Department of Orthopedic Surgery, Hebei Medical University, Shijiazhuang, China.,Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Yu Gou
- Department of Orthopedic Surgery, Tianjin Hospital, Tianjin University, Tianjin, China
| | - Jia-Kang Fang
- Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Yun-Peng Hu
- Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Qiang-Qiang Lian
- Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Zhou Yang
- Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Yu-Ying Zhang
- Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Yu-Dan Wang
- Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Fa-Ming Tian
- Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Liu Zhang
- Department of Orthopedic Surgery, Hebei Medical University, Shijiazhuang, China.,Department of Orthopedic Surgery, Emergency General Hospital, Beijing, China
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12
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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.
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13
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Shao LT, Gou Y, Fang JK, Hu YP, Lian QQ, Zhang YY, Wang YD, Tian FM, Zhang L. Parathyroid hormone (1-34) ameliorates cartilage degeneration and subchondral bone deterioration in collagenase-induced osteoarthritis model in mice. Bone Joint Res 2020; 9:675-688. [PMID: 33101657 PMCID: PMC7563035 DOI: 10.1302/2046-3758.910.bjr-2020-0018.r1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Aims Parathyroid hormone (PTH) (1-34) exhibits potential in preventing degeneration in both cartilage and subchondral bone in osteoarthritis (OA) development. We assessed the effects of PTH (1-34) at different concentrations on bone and cartilage metabolism in a collagenase-induced mouse model of OA and examined whether PTH (1-34) affects the JAK2/STAT3 signalling pathway in this process. Methods Collagenase-induced OA was established in C57Bl/6 mice. Therapy with PTH (1-34) (10 μg/kg/day or 40 μg/kg/day) was initiated immediately after surgery and continued for six weeks. Cartilage pathology was evaluated by gross visual, histology, and immunohistochemical assessments. Cell apoptosis was analyzed by TUNEL staining. Microcomputed tomography (micro-CT) was used to evaluate the bone mass and the microarchitecture in subchondral bone. Results Enhanced matrix catabolism, increased apoptosis of chondrocytes in cartilage, and overexpressed JAK2/STAT3 and p-JAK2/p-STAT3 were observed in cartilage in this model. All of these changes were prevented by PTH (1-34) treatment, with no significant difference between the low-dose and high-dose groups. Micro-CT analysis indicated that bone mineral density (BMD), bone volume/trabecular volume (BV/TV), and trabecular thickness (Tb.Th) levels were significantly lower in the OA group than those in the Sham, PTH 10 μg, and PTH 40 μg groups, but these parameters were significantly higher in the PTH 40 μg group than in the PTH 10 μg group. Conclusion Intermittent administration of PTH (1-34) exhibits protective effects on both cartilage and subchondral bone in a dose-dependent manner on the latter in a collagenase-induced OA mouse model, which may be involved in regulating the JAK2/STAT3 signalling pathway. Cite this article: Bone Joint Res 2020;9(10):675–688.
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Affiliation(s)
- Li-Tao Shao
- Department of Orthopedic Surgery, Hebei Medical University, Shijiazhuang, China.,Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Yu Gou
- Department of Orthopaedic Surgery, Tianjin Hospital, Tianjin University, Tianjin, China
| | - Jia-Kang Fang
- Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Yun-Peng Hu
- Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Qiang-Qiang Lian
- Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Yu-Ying Zhang
- Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Yu-Dan Wang
- Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Fa-Ming Tian
- Medical Research Center, Hebei Key Laboratory for Organ Fibrosis, North China University of Science and Technology, Tangshan, China
| | - Liu Zhang
- Department of Orthopedic Surgery, Hebei Medical University, Shijiazhuang, China.,Department of Orthopedic Surgery, Emergency General Hospital, Beijing, China
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14
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Marta G, Quental C, Folgado J, Guerra-Pinto F. Contact patterns in the ankle joint after lateral ligamentous injury during internal rotation: A computational study. Proc Inst Mech Eng H 2020; 235:82-88. [PMID: 33008273 DOI: 10.1177/0954411920960256] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Lateral ankle instability, resulting from the inability of ankle ligaments to heal after injury, is believed to cause a change in the articular contact mechanics that may promote cartilage degeneration. Considering that lateral ligaments' insufficiency has been related to rotational instability of the talus, and that few studies have addressed the contact mechanics under this condition, the aim of this work was to evaluate if a purely rotational ankle instability could cause non-physiological changes in contact pressures in the ankle joint cartilages using the finite element method. A finite element model of a healthy ankle joint, including bones, cartilages and nine ligaments, was developed. Pure internal talus rotations of 3.67°, 9.6° and 13.43°, measured experimentally for three ligamentous configurations, were applied. The ligamentous configurations consisted in a healthy condition, an injured condition in which the anterior talofibular ligament was cut, and an injured condition in which the anterior talofibular and calcaneofibular ligaments were cut. For all simulations, the contact areas and maximum contact pressures were evaluated for each cartilage. The results showed not only an increase of the maximum contact pressures in the ankle cartilages, but also novel contact regions at the anteromedial and posterolateral sections of the talar cartilage with increasing internal rotation. The anteromedial and posterolateral contact regions observed due to pathological internal rotations of the talus are a computational evidence that supports the link between a pure rotational instability and the pattern of pathological cartilaginous load seen in patients with long-term lateral chronic ankle instability.
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Affiliation(s)
- G Marta
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - C Quental
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - J Folgado
- IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - F Guerra-Pinto
- FEBOT, NOVA Medical School, Lisbon NOVA University, Lisbon, Portugal
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15
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Joukar A, Chande RD, Carpenter RD, Lindsey DP, Erbulut DU, Yerby SA, Duhon B, Goel VK. Effects on hip stress following sacroiliac joint fixation: A finite element study. JOR Spine 2019; 2:e1067. [PMID: 31891117 PMCID: PMC6920688 DOI: 10.1002/jsp2.1067] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 09/06/2019] [Accepted: 09/21/2019] [Indexed: 12/19/2022] Open
Abstract
For those patients who suffer from low back pain generated by the sacroiliac (SI) joint, fusion of the SI joint has proven to be an effective means of stabilizing it and reducing pain. Though it has shown promise, SI joint fusion raises clinical questions regarding its effect on neighboring joints such as the hip. As such, the purpose of this study was to determine the effects of SI joint fixation on the hip. A finite element spine-sacroiliac-hip (SSIH) model was developed and its functionality was verified against SI joint range of motion (ROM) and hip contact stress, respectively. The intact model was fixed in double leg stance at the distal femora, and loading was applied at the lumbar spine to simulate stance, flexion, extension, right and left lateral bending, and right and left axial rotation. Functionality was confirmed by measuring and comparing SI joint ROM and contact stress and area at the hip with data from the literature. Following verification of the intact SSIH model, both unilateral and bilateral SI joint fixation were modeled; hip contact stress and area were compared to the intact state. Average hip contact stress was ~2 MPa, with most motions resulting in changes less than 5% relative to intact; contact area changed less than 10% for any motion. Clinical significance: these results demonstrated that SI joint fixation with triangular titanium implants imparted little change in stress at the hip, which suggests that the risk of developing adjacent segment disease is likely low. Future clinical studies may be executed to confirm the results of this computational study.
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Affiliation(s)
- Amin Joukar
- Engineering Center for Orthopaedic Research Excellence (E‐CORE), Departments of Bioengineering and OrthopaedicsThe University of ToledoToledoOhio
| | | | - R. Dana Carpenter
- Department of Mechanical EngineeringUniversity of Colorado DenverDenverColorado
| | | | - Deniz U. Erbulut
- Engineering Center for Orthopaedic Research Excellence (E‐CORE), Departments of Bioengineering and OrthopaedicsThe University of ToledoToledoOhio
| | | | - Bradley Duhon
- Department of NeurosurgeryUniversity of Colorado DenverDenverColorado
| | - Vijay K. Goel
- Engineering Center for Orthopaedic Research Excellence (E‐CORE), Departments of Bioengineering and OrthopaedicsThe University of ToledoToledoOhio
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16
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Wesseling M, Van Rossom S, Jonkers I, Henak CR. Subject-specific geometry affects acetabular contact pressure during gait more than subject-specific loading patterns. Comput Methods Biomech Biomed Engin 2019; 22:1323-1333. [PMID: 31497996 DOI: 10.1080/10255842.2019.1661393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Finite element modeling (FEM) can predict hip cartilage contact mechanics. This study investigated how subject-specific boundary conditions and joint geometry affect acetabular cartilage contact mechanics using a multi-scale workflow. For two healthy subjects, musculoskeletal models calculated subject-specific hip kinematics and loading, which were used as boundary conditions for FEM. Cartilage contact mechanics were predicted using either generic or subject-specific FEM and boundary conditions. A subject-specific mesh resulted in a more lateral contact. Effects of subject-specific boundary conditions varied between both subjects. Results highlight the complex interplay between loading and kinematics and their effect on cartilage contact mechanics.
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Affiliation(s)
- Mariska Wesseling
- Department of Movement Sciences, Human Movement Biomechanics Research Group, KU Leuven , Leuven , Belgium
| | - Sam Van Rossom
- Department of Movement Sciences, Human Movement Biomechanics Research Group, KU Leuven , Leuven , Belgium
| | - Ilse Jonkers
- Department of Movement Sciences, Human Movement Biomechanics Research Group, KU Leuven , Leuven , Belgium
| | - Corinne R Henak
- Department of Mechanical Engineering, University of Wisconsin , Madison , USA
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Patient Age and Hip Morphology Alter Joint Mechanics in Computational Models of Patients With Hip Dysplasia. Clin Orthop Relat Res 2019; 477:1235-1245. [PMID: 30801275 PMCID: PMC6494307 DOI: 10.1097/corr.0000000000000621] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Older patients (> 30 years) undergoing periacetabular osteotomy (PAO) to delay THA often have inferior patient-reported outcomes than younger adult patients (< 30 years). It is unclear how patient age affects hip morphology, mechanics, or patient-reported outcome scores. QUESTIONS/PURPOSES (1) Is increased patient age associated with computationally derived elevations in joint contact stresses? (2) Does hip shape affect computationally derived joint contact stresses? (3) Do computationally derived joint contact stresses correlate with visual analog scale (VAS) pain scores evaluated at rest in the clinic at a minimum of 1 year after surgery? METHODS A minimum of 1 year of clinical followup was required for inclusion. The first 15 patients younger than 30 years of age, and the first 15 patients older than 30 years of age, who underwent PAO for treatment of classic dysplasia (lateral center-edge angle < 25°) who met the minimum followup were selected from a historical database of patients treated by a single surgeon between April 2003 and April 2010. The older cohort consisted of 14 females and one male with a median age of 41 years (range, 31-54 years). The younger cohort consisted of 10 females and five males with a median age of 19 years (range, 12-29 years). Median followup for the older than 30 years versus younger than 30 years cohort was 19 months (range, 12-37 months) versus 24 months (range, 13-38 months). Pre- and postoperative hip models were created from CT scans for discrete element analysis (DEA) contact stress computations. DEA treats contacting articular surfaces as rigid bodies (bones) separated by a bed of compressive springs (cartilage), the deformation of which governs computation of joint contact stresses. This technique greatly simplifies computational complexity compared with other modeling techniques, which permits patient-specific modeling of larger cohorts. Articular surface shape was assessed by total root mean square deviation of each patient's acetabular and femoral cartilage geometry from sphericity. Preoperative and postoperative VAS pain scores evaluated at rest in the clinic were correlated with computed contact stresses. RESULTS Patients older than 30 years had higher predicted median peak contact stress preoperatively (13 MPa [range, 9-23 MPa; 95% confidence interval {CI}, 11-15 MPa] versus 7 MPa [range, 6-14 MPa; 95% CI, 6-8 MPa], p < 0.001) but not postoperatively (10 MPa [range, 6-18 MPa; 95% CI, 8-12 MPa] versus 8 MPa [range, 6-13 MPa; 95% CI, 7-9 MPa], p = 0.137). Deviation from acetabular sphericity positively correlated with preoperative peak contact stress (R = 0.326, p = 0.002) and was greater in the older cohort (0.9 mm [range, 0.8-1.5 mm; 95% CI, 0.8-1.0 mm] versus 0.8 mm [range, 0.6-0.9 mm; 95% CI, 0.7-0.9 mm], p = 0.014). Peak preoperative contact stress did not correlate with preoperative VAS pain score (R = 0.072, p = 0.229), and no correlation was found between change in peak contact stress and change in VAS score (R = 0.019, p = 0.280). CONCLUSIONS Patients over the age of 30 years with dysplasia had less spherical acetabula and higher predicted preoperative contact stress than those younger than 30 years of age. Future studies with larger numbers of patients and longer term functional outcomes will be needed to determine the role of altered mechanics in the long-term success of PAO varying with patient age. CLINICAL RELEVANCE These findings suggest that long-term exposure to abnormal joint loading may have deleterious effects on the hip geometry and may render the joint less amenable to joint preservation procedures. Given the lack of a direct relationship between mechanics and pain, orthopaedic surgeons should be particularly critical when evaluating three-dimensional dysplastic hip morphology in patients older than 30 years of age to ensure beneficial joint reorientation.
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Bei M, Tian F, Liu N, Zheng Z, Cao X, Zhang H, Wang Y, Xiao Y, Dai M, Zhang L. A Novel Rat Model of Patellofemoral Osteoarthritis Due to Patella Baja, or Low-Lying Patella. Med Sci Monit 2019; 25:2702-2717. [PMID: 30979862 PMCID: PMC6476235 DOI: 10.12659/msm.915018] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Background Patella baja, or patella infera, consists of a low-lying patella that results in a limited range of motion, joint pain, and crepitations. Patellofemoral joint osteoarthritis (PFJOA) is a subtype OA of the knee. This study aimed to develop a reproducible and reliable rat model of PFJOA. Material/Methods Three-month-old female Sprague-Dawley rats (n=24) included a baseline group (n=8) that were euthanized at the beginning of the study. The sham group (n=8), and the patella ligament shortening (PLS) group (n=8) were euthanized and evaluated at ten weeks. The PLS model group (n=8) underwent insertion of a Kirschner wire under the patella tendon to induce patella baja. At ten weeks, the sham group and the PLS group were compared using X-ray imaging, macroscopic appearance, histology, immunohistochemistry, TUNEL staining for apoptosis, and micro-computed tomography (micro-CT). The patella height was determined using the modified Insall-Salvati (MIS) ratio. Results The establishment of the rat model of patella baja in the PLS group at ten weeks was confirmed by X-ray. In the PLS group, patella volume, sagittal length, and cross-sectional area were significantly increased compared with the sham group. The PFJ showed typical lesions of OA, confirmed macroscopically and histologically. Compared with the sham group, in the rat model of PFJOA, there was increased cell apoptosis, and immunohistochemistry showed increased expression of biomarkers of osteoarthritis, compared with the sham group. Conclusions A rat model of PFJOA was developed that was confirmed by changes in cartilage and subchondral bone.
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Affiliation(s)
- Mingjian Bei
- Department of Orthopedic Surgery, Hebei Medical University, Shijiazhuang, Hebei, China (mainland)
| | - Faming Tian
- Meical Research Center, North China University of Science and Technology, Tangshan, Hebei, China (mainland)
| | - Ning Liu
- Department of Orthopedic Surgery, The Affiliated Hospital of North China University of Science and Technology, Tangshan, Hebei, China (mainland)
| | - Zhiyuan Zheng
- Department of Orthopedic Surgery, The Affiliated Hospital of North China University of Science and Technology, Tangshan, Hebei, China (mainland)
| | - Xuehui Cao
- Department of Orthopedic Surgery, The Affiliated Hospital of North China University of Science and Technology, Tangshan, Hebei, China (mainland)
| | - Hongfei Zhang
- Meical Research Center, North China University of Science and Technology, Tangshan, Hebei, China (mainland)
| | - Yudan Wang
- Department of Orthopedic Surgery, The Affiliated Hospital of North China University of Science and Technology, Tangshan, Hebei, China (mainland)
| | - Yaping Xiao
- Department of Orthopedic Surgery, The Affiliated Hospital of North China University of Science and Technology, Tangshan, Hebei, China (mainland)
| | - Muwei Dai
- Department of Orthopedic Surgery, Hebei Medical University, Shijiazhuang, Hebei, China (mainland)
| | - Liu Zhang
- Department of Orthopedic Surgery, Hebei Medical University, Shijiazhuang, Hebei, China (mainland).,Department of Orthopedic Surgery, Meitan General Hospital, Beijing, China (mainland)
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Killian ML, Locke RC, James MG, Atkins PR, Anderson AE, Clohisy JC. Novel model for the induction of postnatal murine hip deformity. J Orthop Res 2019; 37:151-160. [PMID: 30259572 PMCID: PMC6393179 DOI: 10.1002/jor.24146] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 09/12/2018] [Indexed: 02/04/2023]
Abstract
Acetabular dysplasia is a common, multi-etiological, pre-osteoarthritic (OA) feature that can lead to pain and instability of the young adult hip. Despite the clinical significance of acetabular dysplasia, there is a paucity of small animal models to investigate structural and functional changes that mediate morphology of the dysplastic hip and drive the subsequent OA cascade. Utilizing a novel murine model developed in our laboratory, this study investigated the role of surgically induced unilateral instability of the postnatal hip on the initiation and progression of acetabular dysplasia and impingement up to 8-weeks post-injury. C57BL6 mice were used to develop titrated levels of hip instability (i.e., mild, moderate, and severe instabillity or femoral head resection) at weaning. Joint shape, acetabular coverage, histomorphology, and statistical shape modeling were used to assess quality of the hip following 8 weeks of destabilization. Acetabular coverage was reduced following severe, but not moderate, instability. Moderate instability induced lateralization of the femur without dislocation, whereas severe instability led to complete dislocation and pseudoacetabulae formation. Mild instability did not result in morphological changes to the hip. Removal of the femoral head led to reduced hip joint space volume. These data support the notion that hip instability, driven by mechanical loss-of-function of soft connective tissue, can induce morphometric changes in the growing mouse hip. This work developed a new mouse model to study hip health in the murine adolescent hip and is a useful tool for investigating the mechanical and structural adaptations to hip instability during growth. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.
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Affiliation(s)
- Megan L. Killian
- Department of Biomedical Engineering, University of Delaware, 5 Innovation Way, Suite 200, Newark, Delaware 19716,,Department of Orthopaedic Surgery, Washington University School of Medicine, 425 S. Euclid Avenue, Saint Louis, Missouri 63110
| | - Ryan C. Locke
- Department of Biomedical Engineering, University of Delaware, 5 Innovation Way, Suite 200, Newark, Delaware 19716
| | - Michael G. James
- Department of Orthopaedic Surgery, Washington University School of Medicine, 425 S. Euclid Avenue, Saint Louis, Missouri 63110
| | - Penny R. Atkins
- Department of Bioengineering, University of Utah, James LeVoy Sorenson Molecular Biotechnology Building, 36 S. Wasatch Drive, Rm. 3100, Salt Lake City, Utah 84112,,Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, Utah 84108
| | - Andrew E. Anderson
- Department of Bioengineering, University of Utah, James LeVoy Sorenson Molecular Biotechnology Building, 36 S. Wasatch Drive, Rm. 3100, Salt Lake City, Utah 84112,,Department of Orthopaedics, University of Utah, 590 Wakara Way, Salt Lake City, Utah 84108
| | - John C. Clohisy
- Department of Orthopaedic Surgery, Washington University School of Medicine, 425 S. Euclid Avenue, Saint Louis, Missouri 63110
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Kandemir G, Smith S, Joyce TJ. The influence of contact stress on the wear of cross-linked polyethylene. Proc Inst Mech Eng H 2018; 232:1008-1016. [PMID: 30136626 DOI: 10.1177/0954411918796047] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Generation of wear debris and wear particle-induced osteolysis are the main limitations of metal-on-polyethylene artificial joints. Cross-linked polyethylene has been recently used, particularly in hip replacements, as an alternative material to conventional ultrahigh molecular weight polyethylene due to its superior wear resistance. This study focused on the wear behaviour of cross-linked polyethylene under different contact stresses in order to make interpretations of its long-term in-vivo performance. A 50-station SuperCTPOD (pin-on-disc) machine was used to investigate the influence of contact stress on the wear of cross-linked polyethylene pins which were articulated against cobalt chromium discs. It was found that the wear rate of cross-linked polyethylene was lower at higher contact stresses.
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Affiliation(s)
- Göksu Kandemir
- School of Engineering, Newcastle University, Newcastle upon Tyne, UK
| | - Simon Smith
- School of Engineering, Newcastle University, Newcastle upon Tyne, UK
| | - Thomas J Joyce
- School of Engineering, Newcastle University, Newcastle upon Tyne, UK
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21
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Discrete element analysis is a valid method for computing joint contact stress in the hip before and after acetabular fracture. J Biomech 2017; 67:9-17. [PMID: 29221903 DOI: 10.1016/j.jbiomech.2017.11.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 10/30/2017] [Accepted: 11/13/2017] [Indexed: 11/20/2022]
Abstract
Evaluation of abnormalities in joint contact stress that develop after inaccurate reduction of an acetabular fracture may provide a potential means for predicting the risk of developing post-traumatic osteoarthritis. Discrete element analysis (DEA) is a computational technique for calculating intra-articular contact stress distributions in a fraction of the time required to obtain the same information using the more commonly employed finite element analysis technique. The goal of this work was to validate the accuracy of DEA-computed contact stress against physical measurements of contact stress made in cadaveric hips using Tekscan sensors. Four static loading tests in a variety of poses from heel-strike to toe-off were performed in two different cadaveric hip specimens with the acetabulum intact and again with an intentionally malreduced posterior wall acetabular fracture. DEA-computed contact stress was compared on a point-by-point basis to stress measured from the physical experiments. There was good agreement between computed and measured contact stress over the entire contact area (correlation coefficients ranged from 0.88 to 0.99). DEA-computed peak contact stress was within an average of 0.5 MPa (range 0.2-0.8 MPa) of the Tekscan peak stress for intact hips, and within an average of 0.6 MPa (range 0-1.6 MPa) for fractured cases. DEA-computed contact areas were within an average of 33% of the Tekscan-measured areas (range: 1.4-60%). These results indicate that the DEA methodology is a valid method for accurately estimating contact stress in both intact and fractured hips.
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Knight SJ, Abraham CL, Peters CL, Weiss JA, Anderson AE. Changes in chondrolabral mechanics, coverage, and congruency following peri-acetabular osteotomy for treatment of acetabular retroversion: A patient-specific finite element study. J Orthop Res 2017; 35:2567-2576. [PMID: 28370312 PMCID: PMC5623608 DOI: 10.1002/jor.23566] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 03/28/2017] [Indexed: 02/04/2023]
Abstract
UNLABELLED Using a validated finite element (FE) protocol, we quantified cartilage and labrum mechanics, congruency, and femoral coverage in five male patients before and after they were treated for acetabular retroversion with peri-acetabular osteotomy (PAO). Three-dimensional models of bone, cartilage, and labrum were generated from computed tomography (CT) arthrography images, acquired before and after PAO. Walking, stair-ascent, stair-descent, and rising from a chair were simulated. Cartilage and labrum contact stress, contact area, and femoral coverage were calculated overall and regionally. Mean congruency (average of local congruency values for FE nodes in contact) and peak congruency (most incongruent node in contact) were calculated overall and regionally. Load supported by the labrum was represented as a raw change in the ratio of the applied force transferred through the labrum and percent change following surgery (calculated overall only). Considering all activities, following PAO, mean acetabular cartilage contact stress increased medially, superiorly, and posteriorly; peak stress increased medially and posteriorly. Peak labrum stresses decreased overall and superiorly. Acetabular contact area decreased overall and laterally, and increased medially. Labral contact area decreased overall, but not regionally. Load to the labrum decreased. Femoral head coverage increased overall, anterolaterally, and posterolaterally, but decreased anteromedially. Mean congruency indicated the hip became less congruent overall, anteriorly, and posteriorly; peak congruency indicated a less congruent joint posteriorly. CLINICAL RELEVANCE Medialization of contact and reductions in labral loading following PAO may prevent osteoarthritis, but this procedure increases cartilage stresses, decreases contact area, and makes the hip less congruent, which may overload cartilage. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2567-2576, 2017.
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Affiliation(s)
- Spencer J. Knight
- Department of Orthopaedics, University of Utah, Salt Lake City, UT 84108, USA
| | - Christine L. Abraham
- Department of Orthopaedics, University of Utah, Salt Lake City, UT 84108, USA,Department of Bioengineering, University of Utah, Salt Lake City, UT 84112, USA
| | - Christopher L. Peters
- Department of Orthopaedics, University of Utah, Salt Lake City, UT 84108, USA,Department of Bioengineering, University of Utah, Salt Lake City, UT 84112, USA
| | - Jeffrey A. Weiss
- Department of Orthopaedics, University of Utah, Salt Lake City, UT 84108, USA,Department of Bioengineering, University of Utah, Salt Lake City, UT 84112, USA,Scientific Computing and Imaging Institute, Salt Lake City, UT 84112, USA
| | - Andrew E. Anderson
- Department of Orthopaedics, University of Utah, Salt Lake City, UT 84108, USA,Department of Bioengineering, University of Utah, Salt Lake City, UT 84112, USA,Scientific Computing and Imaging Institute, Salt Lake City, UT 84112, USA,Department of Physical Therapy, University of Utah, Salt Lake City, UT 84108, USA
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23
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Atkins PR, Fiorentino NM, Aoki SK, Peters CL, Maak TG, Anderson AE. In Vivo Measurements of the Ischiofemoral Space in Recreationally Active Participants During Dynamic Activities: A High-Speed Dual Fluoroscopy Study. Am J Sports Med 2017; 45:2901-2910. [PMID: 28682639 PMCID: PMC6599761 DOI: 10.1177/0363546517712990] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Ischiofemoral impingement (IFI) is a dynamic process, but its diagnosis is often based on static, supine images. PURPOSE To couple 3-dimensional (3D) computed tomography (CT) models with dual fluoroscopy (DF) images to quantify in vivo hip motion and the ischiofemoral space (IFS) in asymptomatic participants during weightbearing activities and evaluate the relationship of dynamic measurements with sex, hip kinematics, and the IFS measured from axial magnetic resonance imaging (MRI). STUDY DESIGN Cross-sectional study; Level of evidence, 3. METHODS Eleven young, asymptomatic adults (5 female) were recruited. 3D reconstructions of the femur and pelvis were generated from MRI and CT. The axial and 3D IFS were measured from supine MRI. In vivo hip motion during weightbearing activities was quantified using DF. The bone-to-bone distance between the lesser trochanter and ischium was measured dynamically. The minimum and maximum IFS were determined and evaluated against hip joint angles using a linear mixed-effects model. RESULTS The minimum IFS occurred during external rotation for 10 of 11 participants. The IFS measured from axial MRI (mean, 23.7 mm [95% CI, 19.9-27.9]) was significantly greater than the minimum IFS observed during external rotation (mean, 10.8 mm [95% CI, 8.3-13.7]; P < .001), level walking (mean, 15.5 mm [95% CI, 11.4-19.7]; P = .007), and incline walking (mean, 15.8 mm [95% CI, 11.6-20.1]; P = .004) but not for standing. The IFS was reduced with extension (β = 0.66), adduction (β = 0.22), and external rotation (β = 0.21) ( P < .001 for all) during the dynamic activities observed. The IFS was smaller in female than male participants for standing (mean, 20.9 mm [95% CI, 19.3-22.3] vs 30.4 mm [95% CI, 27.2-33.8], respectively; P = .034), level walking (mean, 8.8 mm [95% CI, 7.5-9.9] vs 21.1 mm [95% CI, 18.7-23.6], respectively; P = .001), and incline walking (mean, 9.1 mm [95% CI, 7.4-10.8] vs 21.3 mm [95% CI, 18.8-24.1], respectively; P = .003). Joint angles between the sexes were not significantly different for any of the dynamic positions of interest. CONCLUSION The minimum IFS during dynamic activities was smaller than axial MRI measurements. Compared with male participants, the IFS in female participants was reduced during standing and walking, despite a lack of kinematic differences between the sexes. The relationship between the IFS and hip joint angles suggests that the hip should be placed into greater extension, adduction, and external rotation in clinical examinations and imaging, as the IFS measured from static images, especially in a neutral orientation, may not accurately represent the minimum IFS during dynamic motion. Nevertheless, this statement must be interpreted with caution, as only asymptomatic participants were analyzed herein.
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Affiliation(s)
- Penny R. Atkins
- Department of Orthopaedics, University of Utah, 590 Wakara Way Rm A100, Salt Lake City, UT 84108, USA,Department of Bioengineering, University of Utah, 36 S. Wasatch Drive Rm 3100, Salt Lake City, UT 84112, USA
| | - Niccolo M. Fiorentino
- Department of Orthopaedics, University of Utah, 590 Wakara Way Rm A100, Salt Lake City, UT 84108, USA
| | - Stephen K. Aoki
- Department of Orthopaedics, University of Utah, 590 Wakara Way Rm A100, Salt Lake City, UT 84108, USA
| | - Christopher L. Peters
- Department of Orthopaedics, University of Utah, 590 Wakara Way Rm A100, Salt Lake City, UT 84108, USA,Department of Bioengineering, University of Utah, 36 S. Wasatch Drive Rm 3100, Salt Lake City, UT 84112, USA
| | - Travis G. Maak
- Department of Orthopaedics, University of Utah, 590 Wakara Way Rm A100, Salt Lake City, UT 84108, USA
| | - Andrew E. Anderson
- Department of Orthopaedics, University of Utah, 590 Wakara Way Rm A100, Salt Lake City, UT 84108, USA,Department of Bioengineering, University of Utah, 36 S. Wasatch Drive Rm 3100, Salt Lake City, UT 84112, USA,Scientific Computing and Imaging Institute, University of Utah, 72 S Central Campus Drive Rm 3750, Salt Lake City, UT 84112, USA,Department of Physical Therapy, University of Utah, 520 Wakara Way Suite 240, Salt Lake City, UT 84108, USA
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24
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Patient-specific chondrolabral contact mechanics in patients with acetabular dysplasia following treatment with peri-acetabular osteotomy. Osteoarthritis Cartilage 2017; 25:676-684. [PMID: 27923602 PMCID: PMC6565367 DOI: 10.1016/j.joca.2016.11.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 11/21/2016] [Accepted: 11/28/2016] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Using a validated, patient-specific finite element (FE) modeling protocol, we evaluated cartilage and labrum (i.e., chondrolabral) mechanics before and after peri-acetabular osteotomy (PAO) to provide insight into the ability of this procedure to improve mechanics in dysplastic hips. DESIGN Five patients with acetabular dysplasia were recruited in this case-controlled, prospective study. Models, which included anatomy for bone, cartilage, and labrum, were generated from computed tomography (CT) arthrography scans acquired before and after PAO. Cartilage and labrum contact stress and contact area were quantified overall and regionally. Load supported by the labrum, expressed as a percentage of the total hip force, was analyzed. RESULTS Percent cartilage contact area increased post-operatively overall, medially, and superiorly. Peak acetabular contact stress decreased overall, laterally, anteriorly, and superiorly. Average contact stress decreased overall, laterally, anteriorly, and posteriorly. Only average contact stress on the superior labrum and peak labrum stress overall decreased. Load supported by the labrum did not change significantly. CONCLUSIONS PAO was efficacious at medializing cartilage contact and reducing cartilage contact stresses, and therefore may minimize deleterious loading to focal cartilage lesions, subchondral cysts, and cartilage delaminations often observed in the lateral acetabulum of dysplastic hips. However, the excessively prominent, hypertrophied labrum of dysplastic hips remains in contact with the femoral head, which continues to load the labrum following PAO. The clinical ramifications of continued labral loading following PAO are not known. However, it is plausible that failure to reduce the load experienced by the labrum could result in end-stage hip OA following PAO.
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Vafaeian B, Zonoobi D, Mabee M, Hareendranathan AR, El-Rich M, Adeeb S, Jaremko JL. Finite element analysis of mechanical behavior of human dysplastic hip joints: a systematic review. Osteoarthritis Cartilage 2017; 25:438-447. [PMID: 27836678 DOI: 10.1016/j.joca.2016.10.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 10/20/2016] [Accepted: 10/28/2016] [Indexed: 02/02/2023]
Abstract
Developmental dysplasia of the hip (DDH) is a common condition predisposing to osteoarthritis (OA). Especially since DDH is best identified and treated in infancy before bones ossify, there is surprisingly a near-complete absence of literature examining mechanical behavior of infant dysplastic hips. We sought to identify current practice in finite element modeling (FEM) of DDH, to inform future modeling of infant dysplastic hips. We performed multi-database systematic review using PRISMA criteria. Abstracts (n = 126) fulfilling inclusion criteria were screened for methodological quality, and results were analyzed and summarized for eligible articles (n = 12). The majority of the studies modeled human adult dysplastic hips. Two studies focused on etiology of DDH through simulating mechanobiological growth of prenatal hips; we found no FEM-based studies in infants or children. Finite element models used either patient-specific geometry or idealized average geometry. Diversities in choice of material properties, boundary conditions, and loading scenarios were found in the finite-element models. FEM of adult dysplastic hips demonstrated generally smaller cartilage contact area in dysplastic hips than in normal joints. Contact pressure (CP) may be higher or lower in dysplastic hips depending on joint geometry and mechanical contribution of labrum (Lb). FEM of mechanobiological growth of prenatal hip joints revealed evidence for effects of the joint mechanical environment on formation of coxa valga, asymmetrically shallow acetabulum and malformed femoral head associated with DDH. Future modeling informed by the results of this review may yield valuable insights into optimal treatment of DDH, and into how and why OA develops early in DDH.
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Affiliation(s)
- B Vafaeian
- Department of Civil and Environmental Engineering, University of Alberta, 7-203 Donadeo Innovation Centre for Engineering, 9211-116 Street, Edmonton, Alberta, T6G 1H9, Canada.
| | - D Zonoobi
- Department of Radiology and Diagnostic Imaging, University of Alberta, 2A2.41 WMC, 8440-112 Street, Edmonton, Alberta, T6G 2B7, Canada.
| | - M Mabee
- Department of Radiology and Diagnostic Imaging, University of Alberta, 2A2.41 WMC, 8440-112 Street, Edmonton, Alberta, T6G 2B7, Canada.
| | - A R Hareendranathan
- Department of Radiology and Diagnostic Imaging, University of Alberta, 2A2.41 WMC, 8440-112 Street, Edmonton, Alberta, T6G 2B7, Canada.
| | - M El-Rich
- Department of Civil and Environmental Engineering, University of Alberta, 7-203 Donadeo Innovation Centre for Engineering, 9211-116 Street, Edmonton, Alberta, T6G 1H9, Canada; Department of Mechanical Engineering at Khalifa University (UAE), United Arab Emirates.
| | - S Adeeb
- Department of Civil and Environmental Engineering, University of Alberta, 7-203 Donadeo Innovation Centre for Engineering, 9211-116 Street, Edmonton, Alberta, T6G 1H9, Canada.
| | - J L Jaremko
- Department of Radiology and Diagnostic Imaging, University of Alberta, 2A2.41 WMC, 8440-112 Street, Edmonton, Alberta, T6G 2B7, Canada.
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26
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CORR Insights ®: Increased Hip Stresses Resulting From a Cam Deformity and Decreased Femoral Neck-Shaft Angle During Level Walking. Clin Orthop Relat Res 2017; 475:1009-1012. [PMID: 27785672 PMCID: PMC5339135 DOI: 10.1007/s11999-016-5126-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 10/10/2016] [Indexed: 01/31/2023]
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27
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Elyasi N, Taheri KK, Narooei K, Taheri AK. A study of hyperelastic models for predicting the mechanical behavior of extensor apparatus. Biomech Model Mechanobiol 2017; 16:1077-1093. [DOI: 10.1007/s10237-017-0874-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 01/04/2017] [Indexed: 01/16/2023]
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28
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Dai MW, Chu JG, Tian FM, Song HP, Wang Y, Zhang YZ, Zhang L. Parathyroid hormone(1-34) exhibits more comprehensive effects than celecoxib in cartilage metabolism and maintaining subchondral bone micro-architecture in meniscectomized guinea pigs. Osteoarthritis Cartilage 2016; 24:1103-12. [PMID: 26802547 DOI: 10.1016/j.joca.2016.01.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 12/11/2015] [Accepted: 01/10/2016] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To evaluate the effects of PTH(1-34) on cartilage, subchondral bone mass and structure in medial meniscectomized guinea pigs and compare them to those of celecoxib (CLX). METHOD Forty-eight 3-month-old male Hartley albino guinea pigs received either sham or medial meniscectomy (MNX) operations. One week after the procedure, meniscectomized animals began 12 weeks of treatment by oral administration of CLX (20 mg/kg, daily), subcutaneous injection of PTH (1-34) (24 μg/kg, 5 days/week), or normal saline for MNX group. All animals were euthanized 12 weeks later, cartilage degeneration and subchondral bone micro-architecture was analyzed. RESULTS OARSI scores indicated cartilage degeneration was partially inhibited by either CLX or PTH(1-34). Cartilage was significantly thicker in PTH(1-34)-treated animals than in CLX-treated animals. Both CLX and PTH(1-34) treatment were associated with lower ADAMTS-4 and periostin expression than MNX. MMP-13 expression in PTH(1-34) group was significantly lower than that in CLX group. However, AGG expression and the ratio of Col-II/MMP-13 expression in PTH(1-34) group were significantly higher than in the CLX group. Micro-CT analysis showed BMD, BV/TV, and Tb.Th levels to be significantly lower in the MNX group and CLX groups than in the sham group, but these parameters were significantly higher in the PTH(1-34) group than in either the MNX group or CLX group. CONCLUSIONS Both CLX and PTH(1-34) exhibits protective effects on cartilage degeneration in meniscectomized guinea pigs. However, PTH(1-34) exhibited superior performance to CLX not only in metabolism of cartilage tissue but also in maintenance of subchondral bone micro-architecture.
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Affiliation(s)
- M-W Dai
- Department of Orthopedic Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China.
| | - J-G Chu
- Department of Orthopedic Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China.
| | - F-M Tian
- Medical Research Center, North China University of Science and Technology, Tangshan, China.
| | - H-P Song
- Department of Orthopedic Surgery, The Affiliated Hospital of North China University of Science and Technology, Tangshan, China.
| | - Y Wang
- Department of Orthopedic Surgery, The Affiliated Hospital of North China University of Science and Technology, Tangshan, China.
| | - Y-Z Zhang
- Department of Orthopedic Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China.
| | - L Zhang
- Department of Orthopedic Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, China; Department of Orthopedic Surgery, The Affiliated Hospital of North China University of Science and Technology, Tangshan, China.
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Comparison of Femoral Head Rotation and Varus Collapse Between a Single Lag Screw and Integrated Dual Screw Intertrochanteric Hip Fracture Fixation Device Using a Cadaveric Hemi-Pelvis Biomechanical Model. J Orthop Trauma 2016; 30:164-9. [PMID: 27003028 DOI: 10.1097/bot.0000000000000552] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE This study compared the stabilizing effect of 2 intertrochanteric (IT) fracture fixation devices in a cadaveric hemi-pelvis biomechanical model. METHODS Eleven pairs of cadaveric osteopenic female hemi-pelves with intact hip joint and capsular ligaments were used. An unstable IT fracture (OTA 31-A2) was created in each specimen and stabilized with a single lag screw device (Gamma 3) or an integrated dual screw (IDS) device (InterTAN). The hemi-pelves were inverted, coupled to a biaxial apparatus and subjected to 13.5 k cycles of loading (3 months) using controlled, oscillating pelvic rotation (0-90 degrees) plus cyclic axial femoral loading at a 2:1 body weight (BW) ratio. Femoral head rotation and varus collapse were monitored optoelectonically. For specimens surviving 3 months of loading, additional loading was performed in 0.25 × BW/250 cycle increments to a maximum of 4 × BW or failure. RESULTS Femoral head rotation with IDS fixation was significantly less than the single lag screw construct after 3 months of simulated loading (P = 0.016). Maximum femoral head rotation at the end of 4 × BW loading was 7× less for the IDS construct (P = 0.006). Varus collapse was significantly less with the IDS construct over the entire loading cycle (P = 0.021). CONCLUSIONS In this worst-case model of an osteopenic, unstable, IT fracture, the IDS construct, likely owing to its larger surface area, noncylindrical profile, and fracture compression, provided significantly greater stability and resistance to femoral head rotation and varus collapse.
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Phuntsok R, Mazur MD, Ellis BJ, Ravindra VM, Brockmeyer DL. Development and initial evaluation of a finite element model of the pediatric craniocervical junction. J Neurosurg Pediatr 2016; 17:497-503. [PMID: 26684768 DOI: 10.3171/2015.8.peds15334] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT There is a significant deficiency in understanding the biomechanics of the pediatric craniocervical junction (CCJ) (occiput-C2), primarily because of a lack of human pediatric cadaveric tissue and the relatively small number of treated patients. To overcome this deficiency, a finite element model (FEM) of the pediatric CCJ was created using pediatric geometry and parameterized adult material properties. The model was evaluated under the physiological range of motion (ROM) for flexion-extension, axial rotation, and lateral bending and under tensile loading. METHODS This research utilizes the FEM method, which is a numerical solution technique for discretizing and analyzing systems. The FEM method has been widely used in the field of biomechanics. A CT scan of a 13-month-old female patient was used to create the 3D geometry and surfaces of the FEM model, and an open-source FEM software suite was used to apply the material properties and boundary and loading conditions and analyze the model. The published adult ligament properties were reduced to 50%, 25%, and 10% of the original stiffness in various iterations of the model, and the resulting ROMs for flexion-extension, axial rotation, and lateral bending were compared. The flexion-extension ROMs and tensile stiffness that were predicted by the model were evaluated using previously published experimental measurements from pediatric cadaveric tissues. RESULTS The model predicted a ROM within 1 standard deviation of the published pediatric ROM data for flexion-extension at 10% of adult ligament stiffness. The model's response in terms of axial tension also coincided well with published experimental tension characterization data. The model behaved relatively stiffer in extension than in flexion. The axial rotation and lateral bending results showed symmetric ROM, but there are currently no published pediatric experimental data available for comparison. The model predicts a relatively stiffer ROM in both axial rotation and lateral bending in comparison with flexion-extension. As expected, the flexion-extension, axial rotation, and lateral bending ROMs increased with the decrease in ligament stiffness. CONCLUSIONS An FEM of the pediatric CCJ was created that accurately predicts flexion-extension ROM and axial force displacement of occiput-C2 when the ligament material properties are reduced to 10% of the published adult ligament properties. This model gives a reasonable prediction of pediatric cervical spine ligament stiffness, the relationship between flexion-extension ROM, and ligament stiffness at the CCJ. The creation of this model using open-source software means that other researchers will be able to use the model as a starting point for research.
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Affiliation(s)
- Rinchen Phuntsok
- Department of Bioengineering and Scientific Computing and Imaging Institute, University of Utah; and
| | - Marcus D Mazur
- Department of Neurosurgery, Division of Pediatric Neurosurgery, University of Utah, Primary Children's Hospital, Salt Lake City, Utah
| | - Benjamin J Ellis
- Department of Bioengineering and Scientific Computing and Imaging Institute, University of Utah; and
| | - Vijay M Ravindra
- Department of Neurosurgery, Division of Pediatric Neurosurgery, University of Utah, Primary Children's Hospital, Salt Lake City, Utah
| | - Douglas L Brockmeyer
- Department of Neurosurgery, Division of Pediatric Neurosurgery, University of Utah, Primary Children's Hospital, Salt Lake City, Utah
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Finite element simulation of articular contact mechanics with quadratic tetrahedral elements. J Biomech 2016; 49:659-667. [PMID: 26900037 DOI: 10.1016/j.jbiomech.2016.01.024] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 01/19/2016] [Accepted: 01/28/2016] [Indexed: 11/22/2022]
Abstract
Although it is easier to generate finite element discretizations with tetrahedral elements, trilinear hexahedral (HEX8) elements are more often used in simulations of articular contact mechanics. This is due to numerical shortcomings of linear tetrahedral (TET4) elements, limited availability of quadratic tetrahedron elements in combination with effective contact algorithms, and the perceived increased computational expense of quadratic finite elements. In this study we implemented both ten-node (TET10) and fifteen-node (TET15) quadratic tetrahedral elements in FEBio (www.febio.org) and compared their accuracy, robustness in terms of convergence behavior and computational cost for simulations relevant to articular contact mechanics. Suitable volume integration and surface integration rules were determined by comparing the results of several benchmark contact problems. The results demonstrated that the surface integration rule used to evaluate the contact integrals for quadratic elements affected both convergence behavior and accuracy of predicted stresses. The computational expense and robustness of both quadratic tetrahedral formulations compared favorably to the HEX8 models. Of note, the TET15 element demonstrated superior convergence behavior and lower computational cost than both the TET10 and HEX8 elements for meshes with similar numbers of degrees of freedom in the contact problems that we examined. Finally, the excellent accuracy and relative efficiency of these quadratic tetrahedral elements was illustrated by comparing their predictions with those for a HEX8 mesh for simulation of articular contact in a fully validated model of the hip. These results demonstrate that TET10 and TET15 elements provide viable alternatives to HEX8 elements for simulation of articular contact mechanics.
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Robinson DL, Kersh ME, Walsh NC, Ackland DC, de Steiger RN, Pandy MG. Mechanical properties of normal and osteoarthritic human articular cartilage. J Mech Behav Biomed Mater 2016; 61:96-109. [PMID: 26851527 DOI: 10.1016/j.jmbbm.2016.01.015] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 01/09/2016] [Accepted: 01/19/2016] [Indexed: 10/22/2022]
Abstract
Isotropic hyperelastic models have been used to determine the material properties of normal human cartilage, but there remains an incomplete understanding of how these properties may be altered by osteoarthritis. The aims of this study were to (1) measure the material constants of normal and osteoarthritic human knee cartilage using isotropic hyperelastic models; (2) determine whether the material constants correlate with histological measures of structure and/or cartilage tissue damage; and (3) quantify the abilities of two common isotropic hyperelastic material models, the neo-Hookean and Yeoh models, to describe articular cartilage contact force, area, and pressure. Small osteochondral specimens of normal and osteoarthritic condition were retrieved from human cadaveric knees and from the knees of patients undergoing total knee arthroplasty and tested in unconfined compression at loading rates and large strains representative of weight-bearing activity. Articular surface contact area and lateral deformation were measured concurrently and specimen-specific finite element models then were used to determine the hyperelastic material constants. Structural parameters were measured using histological techniques while the severity of cartilage damage was quantified using the OARSI grading scale. The hyperelastic material constants correlated significantly with OARSI grade, indicating that the mechanical properties of cartilage for large strains change with tissue damage. The measurements of contact area described anisotropy of the tissue constituting the superficial zone. The Yeoh model described contact force and pressure more accurately than the neo-Hookean model, whereas both models under-predicted contact area and poorly described the anisotropy of cartilage within the superficial zone. These results identify the limits by which isotropic hyperelastic material models may be used to describe cartilage contact variables. This study provides novel data for the mechanical properties of normal and osteoarthritic human articular cartilage and enhances our ability to model this tissue using simple isotropic hyperelastic materials.
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Affiliation(s)
- Dale L Robinson
- Dept. of Mechanical Engineering, University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Mariana E Kersh
- Dept. of Mechanical Engineering, University of Melbourne, Parkville, Victoria 3010, Australia; Dept. of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, IL 61801, USA
| | - Nicole C Walsh
- St Vincent׳s Institute of Medical Research and Department of Medicine at St Vincent׳s Hospital, University of Melbourne, Parkville, Victoria 3010, Australia
| | - David C Ackland
- Dept. of Mechanical Engineering, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Richard N de Steiger
- Dept. of Surgery, University of Melbourne, Parkville, Victoria 3010, Australia; Dept. of Surgery, Epworth Healthcare, Melbourne, Victoria 3010, Australia
| | - Marcus G Pandy
- Dept. of Mechanical Engineering, University of Melbourne, Parkville, Victoria 3010, Australia
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Accuracy of Functional and Predictive Methods to Calculate the Hip Joint Center in Young Non-pathologic Asymptomatic Adults with Dual Fluoroscopy as a Reference Standard. Ann Biomed Eng 2015; 44:2168-80. [PMID: 26645080 DOI: 10.1007/s10439-015-1522-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 11/24/2015] [Indexed: 10/22/2022]
Abstract
Predictions from biomechanical models of gait may be sensitive to joint center locations. Most often, the hip joint center (HJC) is derived from locations of reflective markers adhered to the skin. Here, predictive techniques use regression equations of pelvic anatomy to estimate the HJC, whereas functional methods track motion of markers placed at the pelvis and femur during a coordinated motion. Skin motion artifact may introduce errors in the estimate of HJC for both techniques. Quantifying the accuracy of these methods is an area of open investigation. In this study, we used dual fluoroscopy (DF) (a dynamic X-ray imaging technique) and three-dimensional reconstructions from computed tomography images, to measure HJC locations in vivo. Using dual fluoroscopy as the reference standard, we then assessed the accuracy of three predictive and two functional methods. Eleven non-pathologic subjects were imaged with DF and reflective skin marker motion capture. Additionally, DF-based solutions generated virtual markers placed on bony landmarks, which were input to the predictive and functional methods to determine if estimates of the HJC improved. Using skin markers, functional methods had better mean agreement with the HJC measured by DF (11.0 ± 3.3 mm) than predictive methods (18.1 ± 9.5 mm); estimates from functional and predictive methods improved when using the DF-based solutions (1.3 ± 0.9 and 17.5 ± 8.6 mm, respectively). The Harrington method was the best predictive technique using both skin markers (13.2 ± 6.5 mm) and DF-based solutions (10.6 ± 2.5 mm). The two functional methods had similar accuracy using skin makers (11.1 ± 3.6 and 10.8 ± 3.2 mm) and DF-based solutions (1.2 ± 0.8 and 1.4 ± 1.0 mm). Overall, functional methods were superior to predictive methods for HJC estimation. However, the improvements observed when using the DF-based solutions suggest that skin motion artifact is a large source of error for the functional methods.
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SAKAI N, HAGIHARA Y, HASHIMOTO C, KOMORI M, SAWAE Y, MURAKAMI T. An estimation of mechanical propertes of articular cartilage for biphasic finite element analyses. ACTA ACUST UNITED AC 2015. [DOI: 10.1299/jbse.15-00228] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Nobuo SAKAI
- Graduate School of Engineering, Kyushu Institute of Technology
| | | | - Chie HASHIMOTO
- Graduate School of Engineering, Kyushu Institute of Technology
| | | | | | - Teruo MURAKAMI
- Research Center for Advanced Biomechanics, Kyushu University
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Henak CR, Ateshian GA, Weiss JA. Finite element prediction of transchondral stress and strain in the human hip. J Biomech Eng 2014; 136:021021. [PMID: 24292495 DOI: 10.1115/1.4026101] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 11/27/2013] [Indexed: 11/08/2022]
Abstract
Cartilage fissures, surface fibrillation, and delamination represent early signs of hip osteoarthritis (OA). This damage may be caused by elevated first principal (most tensile) strain and maximum shear stress. The objectives of this study were to use a population of validated finite element (FE) models of normal human hips to evaluate the required mesh for converged predictions of cartilage tensile strain and shear stress, to assess the sensitivity to cartilage constitutive assumptions, and to determine the patterns of transchondral stress and strain that occur during activities of daily living. Five specimen-specific FE models were evaluated using three constitutive models for articular cartilage: quasilinear neo-Hookean, nonlinear Veronda Westmann, and tension-compression nonlinear ellipsoidal fiber distribution (EFD). Transchondral predictions of maximum shear stress and first principal strain were determined. Mesh convergence analysis demonstrated that five trilinear elements were adequate through the depth of the cartilage for precise predictions. The EFD model had the stiffest response with increasing strains, predicting the largest peak stresses and smallest peak strains. Conversely, the neo-Hookean model predicted the smallest peak stresses and largest peak strains. Models with neo-Hookean cartilage predicted smaller transchondral gradients of maximum shear stress than those with Veronda Westmann and EFD models. For FE models with EFD cartilage, the anterolateral region of the acetabulum had larger peak maximum shear stress and first principal strain than all other anatomical regions, consistent with observations of cartilage damage in disease. Results demonstrate that tension-compression nonlinearity of a continuous fiber distribution exhibiting strain induced anisotropy incorporates important features that have large effects on predictions of transchondral stress and strain. This population of normal hips provides baseline data for future comparisons to pathomorphologic hips. This approach can be used to evaluate these and other mechanical variables in the human hip and their potential role in the pathogenesis of osteoarthritis (OA).
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Zach L, Kunčická L, Růžička P, Kocich R. Design, analysis and verification of a knee joint oncological prosthesis finite element model. Comput Biol Med 2014; 54:53-60. [PMID: 25212118 DOI: 10.1016/j.compbiomed.2014.08.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 08/16/2014] [Accepted: 08/17/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND The aim of this paper was to design a finite element model for a hinged PROSPON oncological knee endoprosthesis and to verify the model by comparison with ankle flexion angle using knee-bending experimental data obtained previously. METHOD Visible Human Project CT scans were used to create a general lower extremity bones model and to compose a 3D CAD knee joint model to which muscles and ligaments were added. Into the assembly the designed finite element PROSPON prosthesis model was integrated and an analysis focused on the PEEK-OPTIMA hinge pin bushing stress state was carried out. To confirm the stress state analysis results, contact pressure was investigated. The analysis was performed in the knee-bending position within 15.4-69.4° hip joint flexion range. RESULTS The results showed that the maximum stress achieved during the analysis (46.6 MPa) did not exceed the yield strength of the material (90 MPa); the condition of plastic stability was therefore met. The stress state analysis results were confirmed by the distribution of contact pressure during knee-bending. CONCLUSION The applicability of our designed finite element model for the real implant behaviour prediction was proven on the basis of good correlation of the analytical and experimental ankle flexion angle data.
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Affiliation(s)
- Lukáš Zach
- Department of Mechanics, Biomechanics and Mechatronics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technická 4, 166 07 Praha 6, Czech Republic
| | - Lenka Kunčická
- Department of Materials Forming, Faculty of Metallurgy and Materials Engineering, VŠB-TU Ostrava, 17. listopadu 15, Ostrava-Poruba 70833, Czech Republic; Regional Materials Science and Technology Centre, VŠB-TU Ostrava, 17. listopadu 15, Ostrava-Poruba 70833, Czech Republic.
| | - Pavel Růžička
- Department of Mechanics, Biomechanics and Mechatronics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technická 4, 166 07 Praha 6, Czech Republic
| | - Radim Kocich
- Department of Materials Forming, Faculty of Metallurgy and Materials Engineering, VŠB-TU Ostrava, 17. listopadu 15, Ostrava-Poruba 70833, Czech Republic; Regional Materials Science and Technology Centre, VŠB-TU Ostrava, 17. listopadu 15, Ostrava-Poruba 70833, Czech Republic
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Henak CR, Abraham CL, Anderson AE, Maas SA, Ellis BJ, Peters CL, Weiss JA. Patient-specific analysis of cartilage and labrum mechanics in human hips with acetabular dysplasia. Osteoarthritis Cartilage 2014; 22:210-7. [PMID: 24269633 PMCID: PMC3946188 DOI: 10.1016/j.joca.2013.11.003] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 11/06/2013] [Accepted: 11/09/2013] [Indexed: 02/02/2023]
Abstract
BACKGROUND Acetabular dysplasia is a major predisposing factor for development of hip osteoarthritis (OA), and may result from alterations to chondrolabral loading. Subject-specific finite element (FE) modeling can be used to evaluate chondrolabral mechanics in the dysplastic hip, thereby providing insight into mechanics that precede OA. OBJECTIVE To evaluate chondrolabral contact mechanics and congruency in dysplastic hips and normal hips using a validated approach to subject-specific FE modeling. METHODS FE models of ten subjects with normal acetabula and ten subjects with dysplasia were constructed using a previously validated protocol. Labrum load support, and labrum and acetabular cartilage contact stress and contact area were compared between groups. Local congruency was determined at the articular surface for two simulated activities. RESULTS The labrum in dysplastic hips supported 2.8-4.0 times more of the load transferred across the joint than in normal hips. Dysplastic hips did not have significantly different congruency in the primary load-bearing regions than normal hips, but were less congruent in some unloaded regions. Normal hips had larger cartilage contact stress than dysplastic hips in the few regions that had significant differences. CONCLUSIONS The labrum in dysplastic hips has a far more significant role in hip mechanics than it does in normal hips. The dysplastic hip is neither less congruent than the normal hip, nor subjected to elevated cartilage contact stresses. This study supports the concept of an outside-in pathogenesis of OA in dysplastic hips and that the labrum in dysplastic hips should be preserved during surgery.
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Affiliation(s)
- Corinne R Henak
- Department of Bioengineering, and Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112
| | - Christine L Abraham
- Department of Bioengineering, and Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112,Department of Orthopedics, University of Utah, Salt Lake City, UT 84108
| | - Andrew E Anderson
- Department of Bioengineering, and Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112,Department of Orthopedics, University of Utah, Salt Lake City, UT 84108,Department of Physical Therapy, University of Utah, Salt Lake City, UT 84108
| | - Steve A Maas
- Department of Bioengineering, and Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112
| | - Benjamin J Ellis
- Department of Bioengineering, and Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112
| | | | - Jeffrey A Weiss
- Department of Bioengineering, and Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT 84112,Department of Orthopedics, University of Utah, Salt Lake City, UT 84108
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