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Ma J, Xu X. A concise gradient tensor model in quantitatively describing the anisotropic properties of lumbar trabecular bone. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2025:10.1007/s00586-025-08897-8. [PMID: 40332531 DOI: 10.1007/s00586-025-08897-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2024] [Revised: 02/10/2025] [Accepted: 04/28/2025] [Indexed: 05/08/2025]
Abstract
OBJECTIVE This study aimed to evaluate the feasibility of image gradient methods for quantifying directional heterogeneity in lumbar trabecular bone. METHODS A total of 326 male patients' lumbar CT images were collected and grouped by age (20-39 years, 40-59 years, and ≥ 60 years). The tangential gradient calculation was performed on the mid-sagittal plane of the L4 vertebra, and the ratio of the longitudinal to transverse gradient (ratio_σ) was computed to construct a gradient tensor model. Statistical analysis was conducted to assess the differences in ratio_σ among the groups. Individuals with the same bone mineral density were selected to construct finite element models to validate the value of different tensor models for fracture risk assessment. RESULTS Our study results indicate that there is significant directional heterogeneity in the lumbar trabecular core across all age groups, which becomes more pronounced with advancing age, as evidenced by the gradual increase in ratio_σ values (1.44±0.29 for 20-39 years group, 1.86±0.19 for 40-59 years group, and 2.10±0.33 for ≥ 60 years group). Finite element analysis results at the same bone mineral density show that the high tensor group has a higher proportion of fracture risk elements compared to the low tensor group. CONCLUSION The trabecular core shows marked directional heterogeneity with age-dependent variations. Using directional gradient decomposition, we developed gradient tensor models to quantify direction-specific remodeling states in bone microstructures. This tensor-based approach also enables fracture risk assessment at comparable bone mineral density levels.
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Affiliation(s)
- Junchao Ma
- Shaanxi University of Chinese Medicine, Xian Yang, 712000, China.
- Department of Radiology, Shaanxi University of Chinese Medicine, -2# Weiyang Western Road, Xian Yang, 712000, China.
| | - Xiaotong Xu
- Shaanxi University of Chinese Medicine, Xian Yang, 712000, China
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Tani S, Ishikawa K, Chiapparelli E, Camino-Willhuber G, Schönnagel L, Caffard T, Amoroso K, Guven AE, Shue J, Alman BA, Carrino JA, Girardi FP, Sama AA, Cammisa FP, Hughes AP. Impact of Lumbar Degenerative Changes on Vertebral Bone Strength: A Finite Element Analysis. J Orthop Res 2025; 43:931-938. [PMID: 39904732 DOI: 10.1002/jor.26054] [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: 07/26/2024] [Revised: 12/02/2024] [Accepted: 01/02/2025] [Indexed: 02/06/2025]
Abstract
Assessing the bone condition in patients with spinal disease is clinically valuable. However, evaluating bone strength in the presence of spine degenerative changes is challenging. Quantitative computed tomography (QCT) and finite element analysis (FEA) have been proposed as methods for more accurate bone quality assessment. This study investigates the relationship between bone strength predicted by FEA and other relevant biological parameters. This retrospective cross-sectional study included 127 patients with spinal disease who underwent preoperative CT scans between 2014 and 2020. Baseline patient characteristics, volumetric bone mineral density (vBMD) measured by QCT, and vertebral bone strength predicted by FEA were collected. The degree of degeneration was evaluated by classifying osteophyte formation, disc height narrowing, vertebral sclerosis, and spondylolisthesis into a grading scale ranging from 0 to 2. Multiple linear regression analysis was conducted to assess the effect of each factor on bone strength predicted by FEA. Of 127 patients, 120 patients (median age was 62 years) were included. The median vBMD and vertebral strength were 114.3 mg/cm3 and 7892.9 N, respectively. After adjusting for age, sex, body mass index, smoking status, diabetes mellitus, vBMD, and degenerative changes, multiple linear regression analysis revealed that sex, vBMD, and degree of degeneration independently increased the vertebral strength measured by FEA. This study suggests that in patients with spinal disease, vertebral bone strength is affected not only by sex and bone mineral density but also by degenerative changes. Thus, bone strength could be predicted more accurately in patients with spinal disease using FEA.
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Affiliation(s)
- Soji Tani
- Spine Care Institute, Hospital for Special Surgery, New York, New York, USA
- Department of Orthopaedic Surgery, Showa University School of Medicine, Tokyo, Japan
| | - Koji Ishikawa
- Department of Orthopaedic Surgery, Showa University School of Medicine, Tokyo, Japan
- Department of Orthopedic Surgery, Duke University, Durham, North Carolina, USA
| | - Erika Chiapparelli
- Spine Care Institute, Hospital for Special Surgery, New York, New York, USA
| | | | - Lukas Schönnagel
- Spine Care Institute, Hospital for Special Surgery, New York, New York, USA
- Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Thomas Caffard
- Spine Care Institute, Hospital for Special Surgery, New York, New York, USA
- Department of Orthopedic Surgery, University of Ulm, Ulm, Germany
| | - Krizia Amoroso
- Spine Care Institute, Hospital for Special Surgery, New York, New York, USA
| | - Ali E Guven
- Spine Care Institute, Hospital for Special Surgery, New York, New York, USA
| | - Jennifer Shue
- Spine Care Institute, Hospital for Special Surgery, New York, New York, USA
| | - Benjamin A Alman
- Department of Orthopedic Surgery, Duke University, Durham, North Carolina, USA
| | - John A Carrino
- Department of Radiology and Imaging, Hospital for Special Surgery, New York, New York, USA
| | - Federico P Girardi
- Spine Care Institute, Hospital for Special Surgery, New York, New York, USA
| | - Andrew A Sama
- Spine Care Institute, Hospital for Special Surgery, New York, New York, USA
| | - Frank P Cammisa
- Spine Care Institute, Hospital for Special Surgery, New York, New York, USA
| | - Alexander P Hughes
- Spine Care Institute, Hospital for Special Surgery, New York, New York, USA
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Chan AW, Zeng KL, Moore-Palhares D, Atenafu EG, Chen H, Myrehaug S, Ruschin M, Soliman H, Tseng CL, Zhang BB, Whyne C, Maralani P, Sahgal A, Detsky J. Spine Stereotactic Body Radiation Therapy in Geriatric Patients: Implications of Age and Dose on Iatrogenic Vertebral Compression Fracture Risk. Int J Radiat Oncol Biol Phys 2025; 121:1185-1193. [PMID: 39580002 DOI: 10.1016/j.ijrobp.2024.11.082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 10/24/2024] [Accepted: 11/07/2024] [Indexed: 11/25/2024]
Abstract
PURPOSE Stereotactic body radiation therapy (SBRT) is an effective treatment for spinal metastases; however, outcomes specific to a geriatric population have not been described. This study aims to investigate the efficacy and safety of spine SBRT, in particular the rate of iatrogenic vertebral compression fracture (VCF), in patients aged 70 and older. PATIENTS AND METHODS From a prospectively maintained single-institutional database of 976 patients and 2407 spinal segments treated with SBRT for vertebral metastases between 2008 and 2021, all patients aged 70 or above were retrospectively reviewed. The primary outcome is the risk of VCF. Secondary outcomes included magnetic resonance imaging-based local failure and overall survival. RESULTS A total of 252 consecutive patients with 580 spinal segments treated with spine SBRT were reviewed. The median age was 75.8 (range: 70-90.3) years and the median (interquartile range) follow-up duration was 16.9 (6.4-41.3) months. The median overall survival of the entire cohort was 20.3 months and the 2-year local failure rate was 14.3%. The cumulative risk of VCF at 12 and 24 months were 8.4% and 12.3%, respectively. Significant predictors of VCF on multivariable analyses included greater biologically equivalent dose, baseline fracture, and increasing age. In particular, the 2-year VCF rate and median time to VCF were 30.3% and 3.4 months for those 86 and older, compared with 11.2% and 12.8 months for those younger than 86, respectively (P = .0011). CONCLUSION AND RELEVANCE Spine SBRT should be considered in a geriatric population; however, for those 86 and older, we suggest caution due to the significant risk of VCF.
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Affiliation(s)
- Adrian Wai Chan
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Kang Liang Zeng
- Department of Radiation Oncology, Royal Victoria Regional Health Centre, Barrie, Ontario, Canada
| | - Daniel Moore-Palhares
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Eshetu G Atenafu
- Department of Biostatistics, University Health Network, Toronto, Ontario, Canada.
| | - Hanbo Chen
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Sten Myrehaug
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Mark Ruschin
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Hany Soliman
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Chia-Lin Tseng
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Bei-Bei Zhang
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Cari Whyne
- Orthopaedic Biomechanics Lab, Sunnybrook Research Institute, Toronto, Ontario, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada; Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | - Pejman Maralani
- Department of Medical Imaging, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Arjun Sahgal
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Jay Detsky
- Department of Radiation Oncology, Odette Cancer Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.
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Cavazzoni G, Pasini M, Le Maitre CL, Dall'Ara E, Palanca M. Degeneration of the nucleus pulposus affects the internal volumetric strains and failure location of adjacent human metastatic vertebral bodies. Acta Biomater 2025; 194:258-269. [PMID: 39798636 DOI: 10.1016/j.actbio.2025.01.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2024] [Revised: 12/24/2024] [Accepted: 01/09/2025] [Indexed: 01/15/2025]
Abstract
Intervertebral disc (IVD) degeneration is suspected to affect the distribution of stress and strain near the vertebral endplates and in the underlying bone. This scenario is worsened by the presence of metastatic lesions on the vertebrae (primarily thoracic vertebrae (60-80 %)) which increase the risk of fracture. As such, this study aimed to evaluate the effect of IVD degeneration on the internal volumetric strains and failure modes of human metastatic vertebral bodies. Five human thoracic spinal segments including one vertebra with lytic metastases and one radiologically healthy vertebra (control) were in situ tested in pure compression within a μCT scanner (isotropic voxel size = 39μm). Each specimen was tested in the elastic regime before and after inducing mock IVD degeneration (enzymatic degeneration with collagenase); and at failure after IVD degeneration. The volumetric strain field was measured using a global Digital Volume Correlation approach (BoneDVC). After IVD degeneration, larger maximum (+187 %, P = 0.002, 95 % CI= [-4447, -1209]) and minimum (+174 %, P = 0.002, 95% CI= [1679, 4258]) principal strains were observed in both metastatic and control vertebrae, with peak differences in correspondence of the IVD anulus fibrosus. IVD degeneration caused a transversal fracture pattern in the vertebrae with failure location onset in the middle portion of the vertebral body and in the cortical shell. In conclusion, IVD degeneration was found to be a key factor in determining the failure mode, suggesting the clinical relevance of including IVD level of degeneration to assess patients' risk of spinal instability. STATEMENT OF SIGNIFICANCE: Vertebrae can be affected by pathologies, like bone metastases, while intervertebral discs tend to degenerate during life. Generally, these structures and pathologies are studied separately. In this study, we explored the effects of artificial intervertebral disc degeneration on the mineralised tissues of the vertebrae with metastases. We observed that the induced intervertebral disc degeneration changes the mechanical behaviour of the vertebral trabecular bone. We believe that the findings of this study may influence the scientific community to develop new clinical tools for the prediction of the risk of fracture in vertebrae with spinal metastases, including the degeneration of the intervertebral discs as a parameter.
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Affiliation(s)
- Giulia Cavazzoni
- Department of Industrial Engineering, Alma Mater Studiorum - University of Bologna, Via Terracini 28, 40131 Bologna, Italy
| | - Margherita Pasini
- Department of Industrial Engineering, Alma Mater Studiorum - University of Bologna, Via Terracini 28, 40131 Bologna, Italy
| | - Christine L Le Maitre
- Division of Clinical Medicine, School of Medicine and Population Health, The University of Sheffield, Barber House, 387 Glossop Road, Sheffield S10 2HQ, UK; Insigneo Institute, The University of Sheffield, The Pam Liversidge Building, Sheffield S1 3JD, UK
| | - Enrico Dall'Ara
- Division of Clinical Medicine, School of Medicine and Population Health, The University of Sheffield, Barber House, 387 Glossop Road, Sheffield S10 2HQ, UK; Insigneo Institute, The University of Sheffield, The Pam Liversidge Building, Sheffield S1 3JD, UK
| | - Marco Palanca
- Department of Industrial Engineering, Alma Mater Studiorum - University of Bologna, Via Terracini 28, 40131 Bologna, Italy.
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Xie S, Cui L, Wang C, Liu H, Ye Y, Gong S, Li J. Contact between leaked cement and adjacent vertebral endplate induces a greater risk of adjacent vertebral fracture with vertebral bone cement augmentation biomechanically. Spine J 2025; 25:324-336. [PMID: 39343240 DOI: 10.1016/j.spinee.2024.09.021] [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: 05/01/2024] [Revised: 08/13/2024] [Accepted: 09/14/2024] [Indexed: 10/01/2024]
Abstract
BACKGROUND CONTEXT Adjacent vertebral fracture (AVF) is a frequently observed complication after percutaneous vertebroplasty in patients with osteoporotic vertebral compressive fracture (OVCF). Studies have demonstrated that intervertebral cement leakage (ICL) can increase the incidence of AVF, but others have reached opposite conclusions. The stress concentration initially increases the risk of AVF, and dispersive concentrated stress is the main biomechanical function of the intervertebral disc (IVD). PURPOSE This study was designed to validate the hypothesis that direct contact between the leaked cement and adjacent bony endplate (BEP) can inhibit this biomechanical function, trigger adjacent vertebral stress concentration and increase the risk of AVF. STUDY DESIGN A retrospective study and corresponding numerical mechanical simulations. PATIENT SAMPLE Clinical data from 97 OVCF patients treated by bone cement augmentation operations were reviewed in this study. OUTCOME MEASURES Clinical assessments involved measuring ICL and cement-BEP contact status in patients with and without AVF. Numerical simulations were conducted to compute stress values in adjacent vertebral body's BEP and cancellous bone under various body positions. MATERIALS AND METHODS Radiographic and demographic data of 97 OVCF patients (with an average follow-up period of 11.5 months) treated using bone cement augmentation operation were reviewed in the present study. The patients were divided into 2 groups: those with AVF and those without AVF. Bone cement leakage status was judged via 2 different methods: with or without IVD cement leakage and with and without adjacent vertebral endplate contact. The data from patients with and without AVF were compared, and the independent risk factors were identified through regression analysis. Patients without IVD cement leakage, with IVD cement leakage but without adjacent vertebral endplate cement contact, and with direct adjacent vertebral endplate cement contact were simulated using a previously constructed and validated lumbar finite element model, and the biomechanical indicators related to the AVF were computed and recorded in these surgical models. RESULTS Radiographic analysis revealed that the incidence of AVF was numerically higher, but was not significantly higher in patients with IVD cement leakage. In contrast, patients with direct adjacent vertebral endplate cement contact had a significantly greater incidence of AVF, which has also been proven to be an independent risk factor for AVF. In addition, numerical mechanical simulations revealed an obvious stress concentration tendency (the higher maximum equivalent stress value) in the adjacent vertebral body in the model with endplate cement contact. CONCLUSIONS Direct adjacent vertebral endplate cement contact induces a greater risk of AVF through deterioration of the local biomechanical environment. Cement injection, therefore, should be terminated when IVD cement leakage occurs to reduce adjacent vertebral endplate cement contact and reduce the resulting risk of AVF biomechanics.
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Affiliation(s)
- Shiming Xie
- Department of Spine surgery, Mianyang Orthopedic Hospital, Mianyang 621052, Sichuan Province, PR China
| | - Liqiang Cui
- Department of Spine surgery, Mianyang Orthopedic Hospital, Mianyang 621052, Sichuan Province, PR China
| | - Chenglong Wang
- Department of Spine surgery, Mianyang Orthopedic Hospital, Mianyang 621052, Sichuan Province, PR China
| | - Hongjun Liu
- Department of Spine surgery, Mianyang Orthopedic Hospital, Mianyang 621052, Sichuan Province, PR China
| | - Yu Ye
- Department of Spine surgery, Mianyang Orthopedic Hospital, Mianyang 621052, Sichuan Province, PR China
| | - Shuangquan Gong
- Department of Spine surgery, Mianyang Orthopedic Hospital, Mianyang 621052, Sichuan Province, PR China
| | - Jingchi Li
- Department of Orthopedics, Luzhou Key Laboratory of Orthopedic Disorders, The Affiliated Traditional Chinese Medicine Hospital, Southwest Medical University, Luzhou 646000, Sichuan Province, PR China.
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Raftery KA, Kargarzadeh A, Tavana S, Newell N. Disc degeneration influences the strain magnitude and stress distribution within the adjacent trabecular bone. Front Bioeng Biotechnol 2024; 12:1511685. [PMID: 39741500 PMCID: PMC11685154 DOI: 10.3389/fbioe.2024.1511685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2024] [Accepted: 12/02/2024] [Indexed: 01/03/2025] Open
Abstract
Introduction Up to one in five will suffer from osteoporotic vertebral fracture within their lifetime. Accurate fracture prediction poses challenges using bone mineral density (BMD) measures. Trabecular bone strains may be influenced by the underlying intervertebral disc (IVD). Understanding how disc degeneration alters load distribution to the vertebra may demonstrate that supplementing fracture risk tools with IVD metrics could improve predictions. The aim of this study was to assess the influence of IVD degeneration on the stress and strain magnitude and distribution in the trabecular bone of adjacent vertebrae. Methods Ten human cadaveric lumbar bi-segment specimens (20 IVDs, 9 degenerated, 11 non-degenerated) were µCT-imaged under 1000N. Digital volume correlation was used to quantify axial, principal, maximum shear, and von Mises strain in the superior and inferior regions of the vertebra. Volumetric BMD from quantitative-CT was used to calculate Young's modulus, which was then registered with the von Mises strain field to calculate internal von Mises stress. Results Two bi-segments fractured during mechanical testing, resulting in N = 8 endplate regions per group. Trabecular bone adjacent to degenerated IVDs presented higher maximum principal and shear strains in the anterior region, relative to non-degenerated (peak ε1: 6,020 ± 1,633 µε versus 3,737 ± 1,548 µε, p < 0.01; peak γmax: 6,202 ± 1948 µε versus 3,938 ± 2086 µε, p < 0.01). Von Mises stress distribution was significantly skewed towards the anterior region in the degenerated group only (28.3% ± 10.4%, p < 0.05). Reduced disc height correlated with increased central-region axial compressive strain, decreased central-region BMD, and increased anterior region von Mises stress (all p < 0.05). Discussion Disc degeneration may encourage high strains to be experienced within the anterior region of the adjacent bone, owing to changes in load distribution. This study demonstrates the potential of utilising IVD metrics in fracture risk assessment, to inform clinical decision making and preventative treatment.
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Affiliation(s)
| | | | | | - Nicolas Newell
- Department of Bioengineering, Imperial College London, London, United Kingdom
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Mathey E, Pelletier MH, Walsh WR, Gall K, Carpenter D. Implant Strength Contributes to the Osseointegration Strength of Porous Metallic Materials. J Biomech Eng 2024; 146:101005. [PMID: 38668718 DOI: 10.1115/1.4065405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Indexed: 05/14/2024]
Abstract
Creating the optimal environment for effective and long term osseointegration is a heavily researched and sought-after design criteria for orthopedic implants. A validated multimaterial finite element (FE) model was developed to replicate and understand the results of an experimental in vivo push-out osseointegration model. The FE model results closely predicted global force (at 0.5 mm) and stiffness for the 50-90% porous implants with an r2 of 0.97 and 0.98, respectively. In addition, the FE global force at 0.5 mm showed a correlation to the maximum experimental forces with an r2 of 0.90. The highest porosity implants (80-90%) showed lower stiffnesses and more equitable load sharing but also failed at lower a global force level than the low porosity implants (50-70%). The lower strength of the high porosity implants caused premature plastic deformation of the implant itself during loading as well as significant deformations in the ingrown and surrounding bone, resulting in lower overall osseointegration strength, consistent with experimental measurements. The lower porosity implants showed a balance of sufficient bony ingrowth to support osseointegration strength coupled with implant mechanical properties to circumvent significant implant plasticity and collapse under the loading conditions. Together, the experimental and finite element modeling results support an optimal porosity in the range of 60-70% for maximizing osseointegration with current structure and loading.
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Affiliation(s)
- Elizabeth Mathey
- Department of Mechanical Engineering, University of Colorado Denver, 1200 Larimer St, Denver, CO 80204
| | - Matthew H Pelletier
- Prince of Wales Clinical School UNSW Sydney, Surgical and Orthopaedic Research Laboratories (SORL), Kensington 2031, Australia
| | - William R Walsh
- Prince of Wales Clinical School UNSW Sydney, Surgical and Orthopaedic Research Laboratories (SORL), Kensington 2031, Australia
| | - Ken Gall
- Pratt School of Engineering, Duke University, Durham, NC 27708
| | - Dana Carpenter
- Department of Mechanical Engineering, University of Colorado Denver, Denver, CO 80217-3364
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Tomé-Bermejo F, Bartolomé Gómez JF. [Translated article] Anatomical and biomechanical factors of osteoporotic vertebral fracture and the occurrence of cascade fractures. Rev Esp Cir Ortop Traumatol (Engl Ed) 2024:S1888-4415(24)00150-4. [PMID: 39271012 DOI: 10.1016/j.recot.2024.09.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 06/14/2024] [Accepted: 06/20/2024] [Indexed: 09/15/2024] Open
Abstract
Osteoporosis weakens the structural strength of bone to such an extent that normal daily activity may exceed the capacity of the vertebra to bear this load. Vertebral fracture and deformity is a hallmark of osteoporosis. The detriment of trabecular bone properties alone cannot explain the occurrence of osteoporotic vertebral fracture. The ability of the spine to bear and resist loads depends on the structural capacity of the vertebrae, but also on loading conditions arising from activities of daily living or low-energy trauma. This review describes the mechanical properties of the vertebral bone, the structural load-bearing capacity of the various elements forming the spine, the neuromuscular control of the trunk, as well as the biomechanics of the loads to which the spine is subjected in relation to the presence of osteoporosis and the risk of vertebral fracture. A better understanding of biomechanical factors may help to explain both the high incidence of osteoporotic vertebral fractures and their mechanism of production. Consideration of these issues may be important in the development of prevention and management strategies.
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Affiliation(s)
- F Tomé-Bermejo
- Hospital Universitario General de Villalba, Hospital Universitario Fundación Jiménez Díaz, Madrid, Spain.
| | - J F Bartolomé Gómez
- Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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Li S, Zhao X. Anatomical and biomechanical characteristics of basivertebral foramen and its clinical significance. Zhejiang Da Xue Xue Bao Yi Xue Ban 2024; 53:443-449. [PMID: 39183068 PMCID: PMC11375485 DOI: 10.3724/zdxbyxb-2024-0220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Basivertebral foramen is a natural orifice in the posterior wall of the vertebral body existing in humans and mammals, through which the basal vertebral vein, branch of lumbar artery and recurrent branch of spinal nerve enter and exit the vertebral body. Basivertebral foramen changes the local microstructure of the vertebral body, resulting in cortical defect and sparse trabecular bone in the central region of the vertebral body, thus affecting its biomechanical characteristics and making its central region a "weak" area of the vertebra. Some characteristic injuries of the vertebra are related to basivertebral foramen, such as vertebral compression fracture and intervertebral cleft, vertebral burst fracture and posterior upper vertebral fracture fragment, and cement leakage during treatment. In this article, the anatomical and developmental biological characteristics of basivertebral foramen, the impact of basivertebral foramen on biomechanical characteristics, and the treatment of basivertebral foramen related vertebral diseases are reviewed, in order to provide references for the clinical diagnosis and treatment of vertebral injuries.
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Affiliation(s)
- Shengyun Li
- Department of Orthopedics, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, China.
| | - Xing Zhao
- Department of Orthopedics, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, China.
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Wu T, Bonnheim NB, Pendleton MM, Emerzian SR, Keaveny TM. Radiation-induced changes in load-sharing and structure-function behavior in murine lumbar vertebrae. Comput Methods Biomech Biomed Engin 2024; 27:1278-1286. [PMID: 37504955 DOI: 10.1080/10255842.2023.2239415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 07/12/2023] [Indexed: 07/29/2023]
Abstract
In this study, we used micro-CT-based finite element analysis to investigate the biomechanical effects of radiation on the microstructure and mechanical function of murine lumbar vertebrae. Specifically, we evaluated vertebral microstructure, whole-bone stiffness, and cortical-trabecular load sharing in the L5 vertebral body of mice exposed to ionizing radiation 11 days post exposure (5 Gy total dose; n = 13) and controls (n = 14). Our findings revealed the irradiated group exhibited reduced trabecular bone volume and microstructure (p < 0.001) compared to controls, while cortical bone volume remained unchanged (p = 0.91). Axially compressive loads in the irradiated group were diverted from the trabecular centrum and into the vertebral cortex, as evidenced by a higher cortical load-fraction (p = 0.02) and a higher proportion of cortical tissue at risk of initial failure (p < 0.01). Whole-bone stiffness was lower in the irradiated group compared to the controls, though the difference was small and non-significant (2045 ± 142 vs. 2185 ± 225 vs. N/mm, irradiated vs. control, p = 0.07). Additionally, the structure-function relationship between trabecular bone volume and trabecular load fraction differed between groups (p = 0.03), indicating a less biomechanically efficient trabecular network in the irradiated group. We conclude that radiation can decrease trabecular bone volume and result in a less biomechanically efficient trabecular structure, leading to increased reliance on the vertebral cortex to resist axially compressive loads. These findings offer biomechanical insight into the effects of radiation on structure-function behavior in murine lumbar vertebrae independent of possible tissue-level material effects.
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Affiliation(s)
- Tongge Wu
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Noah B Bonnheim
- Department of Orthopaedic Surgery, University of California, San Francisco, CA, USA
| | - Megan M Pendleton
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Shannon R Emerzian
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Tony M Keaveny
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
- Department of Bioengineering, University of California, Berkeley, CA, USA
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Hu T, Dai S, Yang L, Zhu B. Potential Predictive of Thoracic CT Value and Bone Mineral Density T-Value in COPD Complicated with Osteoporosis. Int J Gen Med 2024; 17:3027-3038. [PMID: 39006914 PMCID: PMC11246664 DOI: 10.2147/ijgm.s466292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 06/20/2024] [Indexed: 07/16/2024] Open
Abstract
Background COPD, combined with Osteoporosis, has a high incidence and potential for great harm. Choosing an optimal diagnostic method to achieve bone mineral density (BMD) screening is crucial for COPD patients. Studies on COPD patients with BMD reduction are lacking. Purpose To identify the risk factors of BMD reduction and osteoporosis in COPD patients. Patients and Methods We included a total of 81 patients with AECOPD, who were admitted to the hospital from July 1, 2019, to January 31, 2020. Patients were grouped into BMD normal group, BMD reduced group and OP group. The areas under ROC curve were used to explore the value of CT values in the diagnosis of bone abnormality, and clinical indicators were collected. Results The CT value of the vertebral cancellous bone is highly correlated with the T value of BMD (R > 5.5, P < 0.0001). Using multivariate Logistic regression analysis, we showed that COPD duration, BMI, 25-hydroxyvitamin D3, and long-term inhaled glucocorticoid were independent factors affecting different BMD levels in COPD patients. No significant difference in bone formation indexes between groups. β-crossL was negatively correlated with serum IL-6 (r=-0.254, P=0.022), and ALP was positively correlated with serum TNF-α (r=0.284, P=0.023). Conclusion Thoracolumbar vertebral cancellous bone CT has potential value in the diagnosis of bone abnormality. COPD duration, BMI, 25-hydroxyvitamin D3, and long-term inhaled glucocorticoid may contribute to the BMD reduction in COPD patients, and serum IL-6 and TNF-α regulate bone metabolism in COPD patients.
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Affiliation(s)
- Tinghua Hu
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, 710000, People’s Republic of China
| | - Shanshan Dai
- Department of Respiratory and Critical Care Medicine, Xi’an No. 9 Hospital, Xi’an, Shaanxi, People’s Republic of China
| | - Lan Yang
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, 710000, People’s Republic of China
| | - Bo Zhu
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, 710000, People’s Republic of China
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12
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Korpinen N. Differences in vertebral bone density between African apes. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 184:e24937. [PMID: 38644542 DOI: 10.1002/ajpa.24937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 03/08/2024] [Accepted: 04/02/2024] [Indexed: 04/23/2024]
Abstract
OBJECTIVES Low-energy vertebral fractures are a common health concern, especially in elderly people. Interestingly, African apes do not seem to experience as many vertebral fractures and the low-energy ones are even rarer. One potential explanation for this difference is the lower bone density in humans. Yet, only limited research has been done on the vertebral bone density of the great apes and these have mainly included only single vertebrae. Hence the study aim is to expand our understanding of the vertebral microstructure of African apes in multiple spinal segments. MATERIALS Bone density in the vertebral body of C7, T12, and L3 was measured from 32 Pan troglodytes and 26 Gorilla gorilla using peripheral quantitative computed tomography (pQCT). RESULTS There was a clear difference between the three individual vertebrae and consequently the spinal segments in terms of trabecular density and cortical density and thickness. The variation of these bone parameters between the vertebrae differed between the apes but was also different from those reported for humans. The chimpanzees were observed to have overall higher trabecular density, but gorillas had higher cortical density and thickness. Cortical thickness had a relatively strong association with the vertebral size. DISCUSSION Despite the similarity in locomotion and posture, the results show slight differences in the bone parameters and their variation between spinal segments in African apes. This variation also differs from humans and appears to indicate a complex influence of locomotion, posture, and body size on the different spinal segments.
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Affiliation(s)
- Niina Korpinen
- Department of Archaeology, Faculty of Humanities, University of Oulu, Oulu, Finland
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13
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Tomé-Bermejo F, Bartolomé Gómez JF. Anatomical and biomechanical factors of osteoporotic vertebral fracture and the occurrence of cascade fractures. Rev Esp Cir Ortop Traumatol (Engl Ed) 2024:S1888-4415(24)00112-7. [PMID: 38925424 DOI: 10.1016/j.recot.2024.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 06/14/2024] [Accepted: 06/20/2024] [Indexed: 06/28/2024] Open
Abstract
Osteoporosis weakens the structural strength of bone to such an extent that normal daily activity may exceed the capacity of the vertebra to bear this load. Vertebral fracture and deformity is a hallmark of osteoporosis. The detriment of trabecular bone properties alone cannot explain the occurrence of osteoporotic vertebral fracture. The ability of the spine to bear and resist loads depends on the structural capacity of the vertebrae, but also on loading conditions arising from activities of daily living or low-energy trauma. This review describes the mechanical properties of the vertebral bone, the structural load-bearing capacity of the various elements forming the spine, the neuromuscular control of the trunk, as well as the biomechanics of the loads to which the spine is subjected in relation to the presence of osteoporosis and the risk of vertebral fracture. A better understanding of biomechanical factors may help to explain both the high incidence of osteoporotic vertebral fractures and their mechanism of production. Consideration of these issues may be important in the development of prevention and management strategies.
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Affiliation(s)
- F Tomé-Bermejo
- Hospital Universitario General de Villalba. Hospital Universitario Fundación Jiménez Díaz, Madrid, España.
| | - J F Bartolomé Gómez
- Instituto de Ciencia de Materiales de Madrid. Consejo Superior de Investigaciones Científicas, Madrid, España
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14
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de Kater EP, Blom MN, van Doorn TC, Tieu QH, Jager DJ, Sakes A, Breedveld P. Enhancing spinal bone anchor pull-out resistance with an L-shaped anchor. PLoS One 2024; 19:e0302996. [PMID: 38718026 PMCID: PMC11078376 DOI: 10.1371/journal.pone.0302996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 04/17/2024] [Indexed: 05/12/2024] Open
Abstract
The success rate of spinal fusion surgery is mainly determined by the fixation strength of the spinal bone anchors. This study explores the use of an L-shaped spinal bone anchor that is intended to establish a macro-shape lock with the posterior cortical layer of the vertebral body, thereby increasing the pull-out resistance of the anchor. The performance of this L-shaped anchor was evaluated in lumbar vertebra phantoms (L1-L5) across four distinct perpendicular orientations (lateral, medial, superior, and inferior). During the pull-out experiments, the pull-out force, and the displacement of the anchor with respect to the vertebra was measured which allowed the determination of the maximal pull-out force (mean: 123 N ± 25 N) and the initial pull-out force, the initial force required to start motion of the anchor (mean: 23 N ± 16 N). Notably, the maximum pull-out force was observed when the anchor engaged the cortical bone layer. The results demonstrate the potential benefits of utilising a spinal bone anchor featuring a macro-shape lock with the cortical bone layer to increase the pull-out force. Combining the macro shape-lock fixation method with the conventional pedicle screw shows the potential to significantly enhance the fixation strength of spinal bone anchors.
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Affiliation(s)
- Esther Paula de Kater
- Department of BioMechanical Engineering, Bio-Inspired Technology Group, Faculty of Mechanical Engineering, Delft University of Technology, Delft, Netherlands
| | - Michiel Norbert Blom
- Department of BioMechanical Engineering, Bio-Inspired Technology Group, Faculty of Mechanical Engineering, Delft University of Technology, Delft, Netherlands
| | - Teunis Cornelis van Doorn
- Department of BioMechanical Engineering, Bio-Inspired Technology Group, Faculty of Mechanical Engineering, Delft University of Technology, Delft, Netherlands
| | - Quoc Huy Tieu
- Department of BioMechanical Engineering, Bio-Inspired Technology Group, Faculty of Mechanical Engineering, Delft University of Technology, Delft, Netherlands
| | - David Justin Jager
- Department of Electronic and Mechanical Support Division, Faculty of Electrical Engineering, Mathematics and Computer Science, Delft University of Technology, Delft, Netherlands
| | - Aimée Sakes
- Department of BioMechanical Engineering, Bio-Inspired Technology Group, Faculty of Mechanical Engineering, Delft University of Technology, Delft, Netherlands
| | - Paul Breedveld
- Department of BioMechanical Engineering, Bio-Inspired Technology Group, Faculty of Mechanical Engineering, Delft University of Technology, Delft, Netherlands
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15
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Guitteny S, Lee CF, Amirouche F. Experimentally Validated Finite Element Analysis of Thoracic Spine Compression Fractures in a Porcine Model. Bioengineering (Basel) 2024; 11:96. [PMID: 38247973 PMCID: PMC10813756 DOI: 10.3390/bioengineering11010096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 12/22/2023] [Accepted: 01/11/2024] [Indexed: 01/23/2024] Open
Abstract
Vertebral compression fractures (VCFs) occur in 1 to 1.5 million patients in the US each year and are associated with pain, disability, altered pulmonary function, secondary vertebral fracture, and increased mortality risk. A better understanding of VCFs and their management requires preclinical models that are both biomechanically analogous and accessible. We conducted a study using twelve spinal vertebrae (T12-T14) from porcine specimens. We created mathematical simulations of vertebral compression fractures (VCFs) using CT scans for reconstructing native anatomy and validated the results by conducting physical axial compression experiments. The simulations accurately predicted the behavior of the physical compressions. The coefficient of determination for stiffness was 0.71, the strength correlation was 0.88, and the failure of the vertebral bodies included vertical splitting on the lateral sides or horizontal separation in the anterior wall. This finite element method has important implications for the preventative, prognostic, and therapeutic management of VCFs. This study also supports the use of porcine specimens in orthopedic biomechanical research.
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Affiliation(s)
- Sacha Guitteny
- Department of Orthopaedic Surgery, University of Illinois College of Medicine at Chicago, Chicago, IL 60607, USA; (S.G.); (C.F.L.)
| | - Cadence F. Lee
- Department of Orthopaedic Surgery, University of Illinois College of Medicine at Chicago, Chicago, IL 60607, USA; (S.G.); (C.F.L.)
| | - Farid Amirouche
- Department of Orthopaedic Surgery, University of Illinois College of Medicine at Chicago, Chicago, IL 60607, USA; (S.G.); (C.F.L.)
- Orthopaedic and Spine Institute, NorthShore University Health System, Chicago, IL 60611, USA
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16
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Prado M, Khosla S, Giambini H. Vertebral Fracture Risk Thresholds from Phantom-Less Quantitative Computed Tomography-Based Finite Element Modeling Correlate to Phantom-Based Outcomes. J Clin Densitom 2024; 27:101465. [PMID: 38183962 DOI: 10.1016/j.jocd.2023.101465] [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: 09/26/2023] [Revised: 12/11/2023] [Accepted: 12/13/2023] [Indexed: 01/08/2024]
Abstract
INTRODUCTION Osteoporosis indicates weakened bones and heightened fracture susceptibility due to diminished bone quality. Dual-energy x-ray absorptiometry is unable to assess bone strength. Volumetric bone mineral density (vBMD) from quantitative computed tomography (QCT) has been used to establish guidelines as equivalent measurements for osteoporosis. QCT-based finite element analysis (FEA) has been implemented using calibration phantoms to establish bone strength thresholds based on the established vBMD. The primary aim was to validate vertebral failure load thresholds using a phantom-less approach with previously established thresholds, advancing a phantom-free approach for fracture risk prediction. METHODOLOGY A controlled cohort of 108 subjects (68 females) was used to validate sex-specific vertebral fracture load thresholds for normal, osteopenic, and osteoporotic subjects, obtained using a QCT/FEA-based phantom-less calibration approach and two material equations. RESULTS There were strong prediction correlations between the phantom-less and phantom-based methods (R2: 0.95 and 0.97 for males, and R2: 0.96 and 0.98 for females) based on the two equations. Bland Altman plots and paired t-tests showed no significant differences between methods. Predictions for bone strengths and thresholds using the phantom-less method matched those obtained using the phantom calibration and those previously established, with ≤4500 N (fragile) and ≥6000 N (normal) bone strength in females, and ≤6500 N (fragile) and ≥8500 N (normal) bone strength in males. CONCLUSION Phantom-less QCT-based FEA can allow for prospective and retrospective studies evaluating incidental vertebral fracture risk along the spine and their association with spine curvature and/or fracture etiology. The findings of this study further supported the application of phantom-less QCT-based FEA modeling to predict vertebral strength, aiding in identifying individuals prone to fractures. This reinforces the rationale for adopting this method as a comprehensive approach in predicting and managing fracture risk.
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Affiliation(s)
- Maria Prado
- Department of Biomedical Engineering and Chemical Engineering, One UTSA Circle, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Sundeep Khosla
- Kogod Center on Aging and Division of Endocrinology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Hugo Giambini
- Department of Biomedical Engineering and Chemical Engineering, One UTSA Circle, University of Texas at San Antonio, San Antonio, TX 78249, USA.
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17
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Pu M, Zhang B, Zhu Y, Zhong W, Shen Y, Zhang P. Hounsfield Unit for Evaluating Bone Mineral Density and Strength: Variations in Measurement Methods. World Neurosurg 2023; 180:e56-e68. [PMID: 37544597 DOI: 10.1016/j.wneu.2023.07.146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 07/31/2023] [Indexed: 08/08/2023]
Abstract
OBJECTIVE To assess the consistency and accuracy of various measurements of the Hounsfield unit (HU) in lumbar vertebrae. METHODS The study reviewed lumbar spine computed tomography images of 60 postmenopausal women aged >50 years. A total of 240 vertebrae were measured and analyzed for the variations of HU values in different sections and regions. Investigated the relationship between HU values of the lumbar spine under different measurements and dual-energy X-ray absorptiometry results and the ability to identify patients with osteoporosis. RESULTS HU values measured in midsagittal (r = 0.763), midcoronal (r = 0.768), and midaxial (r = 0.786) sections exhibited a strong positive correlation with dual-energy X-ray absorptiometry T-scores. HU values measured in midsagittal and midaxial sections of the vertebral body were in good agreement (P > 0.1), but decreased in the midcoronal (P < 0.001). HU values in the middle of the vertebral body were significantly higher than in the near end plate (P < 0.001). HU values varied between L1 and L4 vertebrae, but all had a good ability to identify osteoporosis and did not differ significantly in screening ability (P > 0.05). CONCLUSIONS An averaged HU value in axial multilevel is a comprehensive assessment of vertebral bone density. Using the HU value of the lumbar spine can help identify patients with osteoporosis, and the screening ability does not differ significantly across vertebral segments.
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Affiliation(s)
- Mengyang Pu
- Department of Orthopedics, Shaoxing People's Hospital (Shaoxing Hospital, Zhejiang University School of Medicine), Shaoxing Province, Zhejiang, China; Department of Orthopedics, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Bo Zhang
- Department of Radiology, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Ying Zhu
- Department of Orthopedics, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Wentao Zhong
- Department of Orthopedics, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Yixin Shen
- Department of Orthopedics, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China
| | - Peng Zhang
- Department of Orthopedics, Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu Province, China.
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18
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Zhang J, Li H, Zhou Y, Chen S, Rong Q. An Analysis of Trabecular Bone Structure Based on Principal Stress Trajectory. Bioengineering (Basel) 2023; 10:1224. [PMID: 37892954 PMCID: PMC10604682 DOI: 10.3390/bioengineering10101224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 10/11/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
To understand the mechanism of Wolff's law, a finite element analysis was performed for a human proximal femur, and the principal stress trajectories of the femur were extracted using the principal stress visualization method. The mechanism of Wolff's law was evaluated theoretically based on the distribution of the principal stress trajectories. Due to the dynamics of the loads, there was no one-to-one correspondence between the stress trajectories of the fixed load and the trabeculae in the cancellous architecture of the real bone. The trabeculae in the cancellous bone were influenced by the magnitude of the principal stress trajectory. Equivalent principal stress trajectories suitable for different load changes were proposed through the change in load cycle and compared with the anatomical structure of the femur. In addition, the three-dimensional distribution of the femoral principal stress trajectory was established, and the adaptability potential of each load was discussed. The principal stress visualization method could also be applied to bionic structure design.
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Affiliation(s)
| | | | | | | | - Qiguo Rong
- Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing 100871, China; (J.Z.); (H.L.); (Y.Z.); (S.C.)
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19
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Marty AG, Barbone PE, Morgan EF. Multiscale theoretical model shows that aging-related mechanical degradation of cortical bone is driven by microstructural changes in addition to porosity. J Mech Behav Biomed Mater 2023; 145:106029. [PMID: 37499524 PMCID: PMC10528045 DOI: 10.1016/j.jmbbm.2023.106029] [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: 03/01/2023] [Revised: 07/12/2023] [Accepted: 07/14/2023] [Indexed: 07/29/2023]
Abstract
This study aims to gain mechanistic understanding of how aging-related changes in the microstructure of cortical bone drive mechanical consequences at the macroscale. To that end, cortical bone was modeled as a bundle of elastic-plastic, parallel fibers, which represented osteons and interstitial tissue, loaded in uniaxial tension. Distinct material properties were assigned to each fiber in either the osteon or interstitial fiber "families." Models representative of mature (20-60 yrs.) bone, and elderly (60+) bone were created by modeling aging via the following changes to the input parameters: (i) increasing porosity from 5% to 15%, (ii) increasing the ratio of the number of osteon fibers relative to interstitial fibers from 40% to 50%, and (iii) changing the fiber material properties from representing mature bone samples to representing elderly bone samples (i.e., increased strength and decreased toughness of interstitial fibers together with decreased toughness of osteon fibers). To understand the respective contributions of these changes, additional models isolating one or two of each of these were also created. From the computed stress-strain curve for the fiber bundle, the yield point (ϵy, σy), ultimate point (ϵu, σu), and toughness (UT) for the bundle as a whole were measured. We found that changes to all three input parameters were required for the model to capture the aging-related decline in cortical bone mechanical properties consistent with those previously reported in the literature. In both mature and elderly bundles, rupture of the interstitial fibers drove the initial loss of strength following the ultimate point. Plasticity and more gradual rupture of the osteons drove the remainder of the response. Both the onset and completion of interstitial fiber rupture occurred at lower strains in the elderly vs. mature case. These findings point to the importance of studying microstructural changes beyond porosity, such as the area fraction of osteons and the material properties of osteon and interstitial tissue, in order to further understanding of aging-related changes in bone.
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Affiliation(s)
- André Gutiérrez Marty
- Mechanical Engineering, Boston University, 110 Cummington Mall, Boston, 02115, MA, USA; Center for Multiscale and Translational Mechanobiology, Boston University, 110 Cummington Mall, Boston, 02115, MA, USA.
| | - Paul E Barbone
- Mechanical Engineering, Boston University, 110 Cummington Mall, Boston, 02115, MA, USA; Center for Multiscale and Translational Mechanobiology, Boston University, 110 Cummington Mall, Boston, 02115, MA, USA.
| | - Elise F Morgan
- Mechanical Engineering, Boston University, 110 Cummington Mall, Boston, 02115, MA, USA; Center for Multiscale and Translational Mechanobiology, Boston University, 110 Cummington Mall, Boston, 02115, MA, USA; Biomedical Engineering, Boston University, 44 Cummington Mall, Boston, 02115, MA, USA.
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20
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Specht AJ, Steadman DW, Davis M, Bartell SM, Weisskopf MG. Bone lead variability in bone repository skeletal samples measured with portable x-ray fluorescence. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 880:163197. [PMID: 37001655 DOI: 10.1016/j.scitotenv.2023.163197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 03/27/2023] [Accepted: 03/27/2023] [Indexed: 05/27/2023]
Abstract
Bone lead serves as a better, more accessible biomarker to many communities experiencing chronic exposure to lead. A new method using low energy x-ray fluorescence in a handheld device (portable XRF) allows us to measure this chronic biomarker in only a few minutes. However, many unknowns remain about this biomarker measured using a new low energy x-ray technique. The low energy of the new method was theorized to measure a slightly different portion of the bone than previous techniques, which could influence measurements at different bone sites and types. We tested how bone measurements varied across five bone sites: mid-tibial shaft, proximal tibia, distal tibia (ankle), ilium, and cranium. We found bone lead measurements are not significantly different between skeletal elements when measured using a portable XRF. On average, bone lead in the repository samples was measured to be 21.6 ± 21.3 μg/g with an XRF detection limit of 2.1 ± 0.5 μg/g. Cumulative lead exposure can be effectively measured using the portable XRF on a variety of bone types, but the tibia should be preferentially measured to compare between studies and individuals.
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Affiliation(s)
- Aaron J Specht
- School of Health Sciences, Purdue University, West Lafayette, IN, United States of America; Harvard T.H. Chan School of Public Health, Boston, MA, United States of America.
| | - Dawnie W Steadman
- Department of Anthropology, University of Tennessee, Knoxville, TN, United States of America
| | - Mary Davis
- Department of Anthropology, University of Tennessee, Knoxville, TN, United States of America
| | - Scott M Bartell
- Department of Environmental and Occupational Health, Department of Statistics, University of California, Irvine, CA, United States of America
| | - Marc G Weisskopf
- Harvard T.H. Chan School of Public Health, Boston, MA, United States of America
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Li C, Lai XM, Liu N, Lin Y, Hu W. Correlation analysis of the vertebral compression degree and CT HU value in elderly patients with osteoporotic thoracolumbar fractures. J Orthop Surg Res 2023; 18:457. [PMID: 37365576 DOI: 10.1186/s13018-023-03941-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 06/19/2023] [Indexed: 06/28/2023] Open
Abstract
BACKGROUND To explore the correlation of the vertebral compression degree and cancellous bone CT HU in elderly patients with osteoporotic thoracolumbar fractures. METHODS Elderly patients with single-segment vertebral fragility fractures were retrospectively reviewed. All patients experienced a low-energy trauma and underwent thoracolumbar MRI. The consistency of measurement between two spine surgeons was evaluated. The average CT HU value of the adjacent vertebral body was used instead. RESULTS A total of 54 patients were included in the final analysis. The patients' average age was 70.39 ± 8.53 years, and the average CT HU value was 72.78 ± 29.75 HU. The average vertebral compression ratio was 0.57 ± 0.16. Measurements showed both good intrarater repeatability and good interrater reproducibility of the vertebral compression ratio (ICC = 0.978). The degree of vertebral compression in thoracolumbar osteoporotic fractures was strongly positively correlated with the cancellous bone CT HU value (P < 0.01). CONCLUSIONS The local bone quality as evaluated by the CT HU value is an important factor affecting the degree of compression in osteoporotic vertebral fractures. This study provides quantitative evidence that a greater compression ratio with thoracolumbar osteoporotic fractures was associated with lower bone density in elderly patients. Further longitudinal studies with larger cohorts are needed to verify this relationship.
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Affiliation(s)
- Cheng Li
- Department of Orthopaedics, Fifth Clinical Medical College, Guilin Medical University, No. 12 Wenming Road, Guilin, 541002, Guangxi Province, China
| | - Xing-Ming Lai
- Department of Orthopaedics, Fifth Clinical Medical College, Guilin Medical University, No. 12 Wenming Road, Guilin, 541002, Guangxi Province, China
| | - Nian Liu
- Department of Orthopaedics, Fifth Clinical Medical College, Guilin Medical University, No. 12 Wenming Road, Guilin, 541002, Guangxi Province, China
| | - Yang Lin
- Department of Orthopaedics, Fifth Clinical Medical College, Guilin Medical University, No. 12 Wenming Road, Guilin, 541002, Guangxi Province, China
| | - Wei Hu
- Department of Orthopaedics, Fifth Clinical Medical College, Guilin Medical University, No. 12 Wenming Road, Guilin, 541002, Guangxi Province, China.
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de Kater EP, Müller R, Sakes A, Breedveld P. Tsetse fly inspired steerable bone drill-a proof of concept. Front Bioeng Biotechnol 2023; 11:1197940. [PMID: 37351466 PMCID: PMC10284141 DOI: 10.3389/fbioe.2023.1197940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/29/2023] [Indexed: 06/24/2023] Open
Abstract
The fixation strength of pedicle screws could be increased by fixating along the much stronger cortical bone layer, which is not possible with the current rigid and straight bone drills. Inspired by the tsetse fly, a single-plane steerable bone drill was developed. The drill has a flexible transmission using two stacked leaf springs such that the drill is flexible in one plane and can drill along the cortical bone layer utilizing wall guidance. A proof-of-principle experiment was performed which showed that the Tsetse Drill was able to successfully drill through 5, 10 and 15 PCF cancellous bone phantom which has similar mechanical properties to severe osteoporotic, osteoporotic and healthy cancellous bone. Furthermore, the Tsetse Drill was able to successfully steer and drill along the cortical wall utilizing wall guidance for an insertion angle of 5°, 10° and 15°. The experiments conclude that the tsetse fly-inspired drilling method is successful and even allows the drilling along the cortical bone layer. The Tsetse Drill can create curved tunnels utilizing wall guidance which could increase the fixation strength of bone anchors and limit the risk of cortical breach and damage to surrounding anatomy.
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23
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Palanca M, Cavazzoni G, Dall'Ara E. The role of bone metastases on the mechanical competence of human vertebrae. Bone 2023:116814. [PMID: 37257631 DOI: 10.1016/j.bone.2023.116814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/03/2023] [Accepted: 05/23/2023] [Indexed: 06/02/2023]
Abstract
Spine is the most common site for bone metastases. The evaluation of the mechanical competence and failure location in metastatic vertebrae is a biomechanical and clinical challenge. Little is known about the failure behaviour of vertebrae with metastatic lesions. The aim of this study was to use combined micro-Computed Tomography (microCT) and time-lapsed mechanical testing to reveal the failure location in metastatic vertebrae. Fifteen spine segments, each including a metastatic and a radiologically healthy vertebra, were tested in compression up to failure within a microCT. Volumetric strains were measured using Digital Volume Correlation. The images of undeformed and deformed specimens were overlapped to identify the failure location. Vertebrae with lytic metastases experienced the largest average compressive strains (median ± standard deviation: -8506 ± 4748microstrain), followed by the vertebrae with mixed metastases (-7035 ± 15605microstrain), the radiologically healthy vertebrae (-5743 ± 5697microstrain), and the vertebrae with blastic metastases (-3150 ± 4641microstrain). Strain peaks were localised within and nearby the lytic lesions or around the blastic tissue. Failure between the endplate and the metastasis was identified in vertebrae with lytic metastases, whereas failure localised around the metastasis in vertebrae with blastic lesions. This study showed for the first time the role of metastases on the vertebral internal deformations. While lytic lesions lead to failure of the metastatic vertebra, vertebrae with blastic metastases are more likely to induce failure in the adjacent vertebrae. Nevertheless, every metastatic lesion affects the vertebral deformation differently, making it essential to assess how the lesion affects the bone microstructure. These results suggest that the properties of the lesion (type, size, location within the vertebral body) should be considered when developing clinical tools to predict the risk of fracture in patients with metastatic lesions.
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Affiliation(s)
- Marco Palanca
- Dept of Oncology and Metabolism, The University of Sheffield, Sheffield, UK; INSIGNEO Institute for In Silico Medicine, The University of Sheffield, Sheffield, UK; Dept of Industrial Engineering, Alma Mater Studiorum - University of Bologna, Bologna, Italy.
| | - Giulia Cavazzoni
- Dept of Oncology and Metabolism, The University of Sheffield, Sheffield, UK; INSIGNEO Institute for In Silico Medicine, The University of Sheffield, Sheffield, UK; Dept of Industrial Engineering, Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | - Enrico Dall'Ara
- Dept of Oncology and Metabolism, The University of Sheffield, Sheffield, UK; INSIGNEO Institute for In Silico Medicine, The University of Sheffield, Sheffield, UK
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Baleani M, Fraterrigo G, Erani P, Rota G, Berni M, Taddei F, Schileo E. Applying a homogeneous pressure distribution to the upper vertebral endplate: Validation of a new loading system, pilot application to human vertebral bodies, and finite element predictions of DIC measured displacements and strains. J Mech Behav Biomed Mater 2023; 140:105706. [PMID: 36841124 DOI: 10.1016/j.jmbbm.2023.105706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/24/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023]
Abstract
Image-based personalized Finite Element Models (pFEM) could detect alterations in physiological deformation of human vertebral bodies, but their accuracy has been seldom reported. Meaningful validation experiments should allow vertebral endplate deformability and ensure well-controlled boundary conditions. This study aimed to (i) validate a new loading system to apply a homogeneous pressure on the vertebral endplate during vertebral body compression regardless of endplate deformation; (ii) perform a pilot study on human vertebral bodies measuring surface displacements and strains with Digital Image Correlation (DIC); (iii) determine the accuracy of pFEM of the vertebral bodies. Homogeneous pressure application was achieved by pressurizing a fluid silicone encased in a rubber silicone film acting on the cranial endplate. The loading system was validated by comparing DIC-measured longitudinal strains and lower-end contact pressures, measured on three homogeneous pseudovertebrae of constant transversal section at 2.0 kN, against theoretically calculated values. Longitudinal strains and contact pressures were rather homogeneous, and their mean values close to theoretical calculations (5% underestimation). DIC measurements of surface longitudinal and circumferential displacements and strains were obtained on three human vertebral bodies at 2.0 kN. Complete displacement and strain maps were achieved for anterolateral aspects with random errors ≤0.2 μm and ≤30 μstrain, respectively. Venous plexus and double curvatures limited the completeness and accuracy of DIC data in posterior aspects. pFEM of vertebral bodies, including cortical bone mapping, were built from computed tomography images. In anterolateral aspects, pFEM accuracy of the three vertebrae was: (i) comparable to literature in terms of longitudinal displacements (R2>0.8); (ii) extended to circumferential displacements (pooled data: R2>0.9) and longitudinal strains (zero median error, 95% error: <27%). Circumferential strains were overestimated (median error: 39%). The new methods presented may permit to study how physiological and pathologic conditions influence the ability of vertebral endplates/bodies to sustain loads.
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Affiliation(s)
- Massimiliano Baleani
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Tecnologia Medica, Bologna, Italy.
| | - Giulia Fraterrigo
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Bioingegneria Computazionale, Bologna, Italy
| | - Paolo Erani
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Tecnologia Medica, Bologna, Italy
| | - Giulia Rota
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Tecnologia Medica, Bologna, Italy
| | - Matteo Berni
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Tecnologia Medica, Bologna, Italy
| | - Fulvia Taddei
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Bioingegneria Computazionale, Bologna, Italy
| | - Enrico Schileo
- IRCCS Istituto Ortopedico Rizzoli, Laboratorio di Bioingegneria Computazionale, Bologna, Italy.
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25
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Levy RV, McMahon DJ, Agarwal S, Dempster D, Zhou H, Misof BM, Guo X, Kamanda-Kosseh M, Aponte MA, Reidy K, Kumar J, Fusaro M, Brown DD, Melamed ML, Nickolas TL. Comprehensive Associations between Acidosis and the Skeleton in Patients with Kidney Disease. J Am Soc Nephrol 2023; 34:668-681. [PMID: 36749125 PMCID: PMC10103353 DOI: 10.1681/asn.0000000000000085] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 01/10/2023] [Indexed: 02/08/2023] Open
Abstract
SIGNIFICANCE STATEMENT Renal osteodystrophy (ROD) contributes substantially to morbidity in CKD, including increased fracture risk. Metabolic acidosis (MA) contributes to the development of ROD, but an up-to-date skeletal phenotype in CKD-associated acidosis has not been described. We comprehensively studied associations between acidosis and bone in patients with CKD using advanced methods to image the skeleton and analyze bone-tissue, along with biochemical testing. Cross-sectionally, acidosis was associated with higher markers of bone remodeling and female-specific impairments in cortical and trabecular bone quality. Prospectively, acidosis was associated with cortical expansion and trabecular microarchitectural deterioration. At the bone-tissue level, acidosis was associated with deficits in bone mineral content. Future work investigating acidosis correction on bone quality is warranted. BACKGROUND Renal osteodystrophy is a state of impaired bone quality and strength. Metabolic acidosis (MA) is associated with alterations in bone quality including remodeling, microarchitecture, and mineralization. No studies in patients with CKD have provided a comprehensive multimodal skeletal phenotype of MA. We aim to describe the structure and makeup of bone in patients with MA in the setting of CKD using biochemistry, noninvasive imaging, and histomorphometry. METHODS The retrospective cross-sectional analyses included 180 patients with CKD. MA was defined as bicarbonate ≤22 mEq/L. We evaluated circulating bone turnover markers and skeletal imaging with dual energy x-ray absorptiometry and high-resolution peripheral computed tomography. A subset of 54 participants had follow-up. We assessed associations between baseline and change in bicarbonate with change in bone outcomes. Histomorphometry, microCT, and quantitative backscatter electron microscopy assessed bone biopsy outcomes in 22 participants. RESULTS The mean age was 68±10 years, 54% of participants were male, and 55% were White. At baseline, acidotic subjects had higher markers of bone turnover, lower areal bone mineral density at the radius by dual energy x-ray absorptiometry, and lower cortical and trabecular volumetric bone mineral density and impaired trabecular microarchitecture. Over time, acidosis was associated with opposing cortical and trabecular effects: cortical expansion but trabecular deterioration. Bone-tissue analyses showed reduced tissue mineral density with increased heterogeneity of calcium distribution in acidotic participants. CONCLUSIONS MA is associated with multiple impairments in bone quality. Future work should examine whether correction of acidosis improves bone quality and strength in patients with CKD.
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Affiliation(s)
- Rebecca V. Levy
- Nephrology, Department of Medicine, University of Rochester Medical Center Rochester, New York, USA
- Pediatric Nephrology, Department of Pediatrics, University of Rochester Medical Center, Rochester, New York, USA
| | | | | | - David Dempster
- Columbia University Irving Medical Center, New York, USA
| | - Hua Zhou
- Columbia University Irving Medical Center, New York, USA
| | - Barbara M. Misof
- Ludwig Boltzmann Institute for Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - X.E. Guo
- Columbia University Biomedical Engineering, New York, New York, USA
| | | | | | - Kimberly Reidy
- Nephrology, Department of Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, New York
| | - Juhi Kumar
- Nephrology, Department of Pediatrics, Weill-Cornell Medical Center, New York, New York
| | - Maria Fusaro
- National Research Council (CNR), Institute of Clinical Physiology (IFC), Pisa, Italy
- Department of Medicine, University of Padova, Padova, Padua, Italy
| | - Denver D. Brown
- Division of Nephrology, Children's National Hospital, Washington, DC
| | - Michal L. Melamed
- Nephrology, Department of Medicine, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, New York
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Li J, Zhang Z, Xie T, Song Z, Song Y, Zeng J. The preoperative Hounsfield unit value at the position of the future screw insertion is a better predictor of screw loosening than other methods. Eur Radiol 2023; 33:1526-1536. [PMID: 36241918 PMCID: PMC9935714 DOI: 10.1007/s00330-022-09157-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/11/2022] [Accepted: 09/09/2022] [Indexed: 11/04/2022]
Abstract
OBJECTIVE Screw loosening is a widely reported issue after spinal screw fixation and triggers several complications after lumbar interbody fusion. Osteoporosis is an essential risk factor for screw loosening. Hounsfield units (HU) value is a credible indicator during bone mineral density (BMD) evaluation. As compared with the general evaluation of BMD, we hypothesized that specific measurements of HU at the precise location of the future screw insertion may be a better predictor of screw loosening. METHODS Clinical data of 56 patients treated by oblique lumbar interbody fusion (OLIF) of the L4-L5 segments with an anterior lateral single rod (ALSR) screw fixation were reviewed in this study. Vertebral bodies with ≥ 1 mm width radiolucent zones around the screw were defined as screw loosening. HU in the insertional screw positions, the central transverse plane, and the average values of three and four planes were measured. Regression analyses identified independent risk factors for screw loosening separately. The area under the receiver operating characteristic curve (AUC) was computed to evaluate predictive performance. RESULTS The local HU values were significantly lower in the loosening group, regardless of the selected measuring methods. The AUC of screw loosening prediction was higher in the insertional screw positions' HU than other frequently used methods. CONCLUSIONS The HU value measured in the insertional screw position is a better predictor of ALSR screw loosening than other methods. The risk of screw loosening should be reduced by optimizing the trajectory of the screw based on the measurement of HU in preoperative CT. KEY POINTS • Osteoporosis is an essential risk factor for screw loosening, and Hounsfield units (HU) are a credible predictor during bone mineral density (BMD) evaluation. • The HU value measured in the insertional screw position is a better predictor of screw loosening than other frequently used HU measurement methods. • The risk of screw loosening might potentially be reduced by optimizing the trajectory of the screw based on the measurement of HU in preoperative CT.
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Affiliation(s)
- Jingchi Li
- grid.412901.f0000 0004 1770 1022Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine, Sichuan University, 37# Wuhou Guoxue Road, Chengdu, 610041 Sichuan Province People’s Republic of China
| | - Zhuang Zhang
- grid.412901.f0000 0004 1770 1022Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine, Sichuan University, 37# Wuhou Guoxue Road, Chengdu, 610041 Sichuan Province People’s Republic of China
| | - Tianhang Xie
- grid.412901.f0000 0004 1770 1022Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine, Sichuan University, 37# Wuhou Guoxue Road, Chengdu, 610041 Sichuan Province People’s Republic of China
| | - Zhetao Song
- grid.13291.380000 0001 0807 1581Department of Imaging, Sichuan University, Chengdu, Sichuan People’s Republic of China
| | - Yueming Song
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine, Sichuan University, 37# Wuhou Guoxue Road, Chengdu, 610041, Sichuan Province, People's Republic of China.
| | - Jiancheng Zeng
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital/West China School of Medicine, Sichuan University, 37# Wuhou Guoxue Road, Chengdu, 610041, Sichuan Province, People's Republic of China.
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27
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Zhou LP, Shang J, Zhang ZG, Jiang ZF, Zhang HQ, Jia CY, Zhang RJ, Shen CL. Characteristics and Comparisons of Morphometric Measurements and Computed Tomography Hounsfield Unit Values of C2 Laminae for Translaminar Screw Placement Between Patients With and Without Basilar Invagination. Neurospine 2022; 19:899-911. [PMID: 36597627 PMCID: PMC9816593 DOI: 10.14245/ns.2244730.365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/24/2022] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE Patients with basilar invagination (BI) had high incidences of vertebral variations and high-riding vertebral artery (HRVA) that might restrict the use of pedicle or pars screw and increase the use of translaminar screw on axis. Here, we conducted a radiographic study to investigate the feasibility of translaminar screws and the bone quality of C2 laminae in patients with BI, which were compared with those without BI as control to provide guidelines for safe placement. METHODS In this study, a total of 410 patients (205 consecutive patients with BI and 205 matched patients without BI) and 820 unilateral laminae of the axis were included at a 1:1 ratio. Comparisons with regard to insertion parameters (laminar length, thickness, angle, and height) for C2 translaminar screw placement and Hounsfield unit (HU) values for the assessment of the appropriate bone mineral density of C2 laminae between BI and control groups were performed. Besides, the subgroup analyses based on the Goel A and B classification of BI, HRVA, atlas occipitalization, and C2/3 assimilation were also carried out. Furthermore, the factors that might affect the insertion parameters and HU values were explored through multiple linear regression analyses. RESULTS The BI group showed a significantly smaller laminar length, thickness, height, and HU value than the control group, whereas no significant difference was observed regarding the laminar angle. By contrast, the control group showed significantly higher rates of acceptability for unilateral and bilateral translaminar screw fixations than the BI group. Subgroup analyses showed that the classification of Goel A and B, HRVA, atlas occipitalization, and C2/3 assimilation affected the insertion parameters except the HU values. Multiple linear regression indicated that the laminar length was significantly associated with the male gender (B = 0.190, p < 0.001), diagnoses of HRVA (B = -0.109, p < 0.001), Goel A (B = -0.167, p < 0.001), and C2/3 assimilation (B = -0.079, p = 0.029); the laminar thickness was significantly associated with the male gender (B = 0.353, p < 0.001), diagnoses of HRVA (B = -0.430, p < 0.001), Goel B (B = -0.249, p = 0.026), and distance from the top of odontoid to the Chamberlain line (B = -0.025, p = 0.003); laminar HU values were significantly associated with age (B = -2.517, p < 0.001), Goel A (B = -44.205, p < 0.001), Goel B (B = -25.704, p = 0.014), and laminar thickness (B = -11.706, p = 0.001). CONCLUSION Patients with BI had narrower and smaller laminae with lower HU values and lower unilateral and bilateral acceptability for translaminar screws than patients without BI. Preoperative 3-dimensional computed tomography (CT) and CT angiography were needed for BI patients.
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Affiliation(s)
- Lu-Ping Zhou
- Department of Orthopedics, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Jin Shang
- Department of Radiology, the First Affiliated Hospital of University of Science and Technology of China, Hefei, Anhui, China
| | - Zhi-Gang Zhang
- Department of Orthopedics, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Zhen-Fei Jiang
- Department of Orthopedics, the First Affiliated Hospital of University of Science and Technology of China, Hefei, Anhui, China
| | - Hua-Qing Zhang
- Department of Orthopedics, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Chong-Yu Jia
- Department of Orthopedics, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Ren-Jie Zhang
- Department of Orthopedics, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China,Co-corresponding Author Ren-Jie Zhang Department of Orthopedics, the First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, Anhui 230022, China
| | - Cai-Liang Shen
- Department of Orthopedics, the First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China,Corresponding Author Cai-Liang Shen Department of Orthopedics, the First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, Anhui 230022, China
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28
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Yeni YN, Dix MR, Xiao A, Oravec DJ, Flynn MJ. Measuring the thickness of vertebral endplate and shell using digital tomosynthesis. Bone 2022; 157:116341. [PMID: 35092890 PMCID: PMC8858866 DOI: 10.1016/j.bone.2022.116341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 12/07/2021] [Accepted: 01/23/2022] [Indexed: 02/05/2023]
Abstract
The vertebral endplate and cortical shell play an important structural role and contribute to the overall strength of the vertebral body, are at highest risk of initial failure, and are involved in degenerative disease of the spine. The ability to accurately measure the thickness of these structures is therefore important, even if difficult due to relatively low resolution clinical imaging. We posit that digital tomosynthesis (DTS) may be a suitable imaging modality for measurement of endplate and cortical shell thickness owing to the ability to reconstruct multiplanar images with good spatial resolution at low radiation dose. In this study, for 25 cadaveric L1 vertebrae, average and standard deviation of endplate and cortical shell thickness were measured using images from DTS and microcomputed tomography (μCT). For endplate thickness measurements, significant correlations between DTS and μCT were found for all variables when comparing thicknesses measured in both the overall endplate volume (R2 = 0.25-0.54) and when measurements were limited to a central range of coronal or sagittal slices (R2 = 0.24-0.62). When compared to reference values from the overall shell volume, DTS thickness measurements were generally nonsignificant. However, when measurement of cortical shell thickness was limited to a range of central slices, DTS outcomes were significantly correlated with reference values for both sagittal and coronal central regions (R2 = 0.21-0.49). DTS may therefore offer a means for measurement of endplate thickness and, within a limited sagittal or coronal measurement volume, for measurement of cortical shell thickness.
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Affiliation(s)
- Yener N Yeni
- Bone and Joint Center, Henry Ford Hospital, Detroit, MI, United States of America.
| | - Michael R Dix
- Bone and Joint Center, Henry Ford Hospital, Detroit, MI, United States of America; School of Medicine, Wayne State University, Detroit, MI, United States of America
| | - Angela Xiao
- Bone and Joint Center, Henry Ford Hospital, Detroit, MI, United States of America
| | - Daniel J Oravec
- Bone and Joint Center, Henry Ford Hospital, Detroit, MI, United States of America
| | - Michael J Flynn
- Bone and Joint Center, Henry Ford Hospital, Detroit, MI, United States of America
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29
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Smith SM, Angielczyk KD. A Shrewd Inspection of Vertebral Regionalization in Large Shrews (Soricidae: Crocidurinae). Integr Org Biol 2022; 4:obac006. [PMID: 35291671 PMCID: PMC8915212 DOI: 10.1093/iob/obac006] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The regionalization of the mammalian spinal column is an important evolutionary, developmental, and functional hallmark of the clade. Vertebral column regions are usually defined using transitions in external bone morphology, such as the presence of transverse foraminae or rib facets, or measurements of vertebral shape. Yet the internal structure of vertebrae, specifically the trabecular (spongy) bone, plays an important role in vertebral function, and is subject to the same variety of selective, functional, and developmental influences as external bone morphology. Here, we investigated regionalization of external and trabecular bone morphology in the vertebral column of a group of shrews (family Soricidae). The primary goals of this study were to: (1) determine if vertebral trabecular bone morphology is regionalized in large shrews, and if so, in what configuration relative to external morphology; (2) assess correlations between trabecular bone regionalization and functional or developmental influences; and (3) determine if external and trabecular bone regionalization patterns provide clues about the function of the highly modified spinal column of the hero shrew Scutisorex. Trabecular bone is regionalized along the soricid vertebral column, but the configuration of trabecular bone regions does not match that of the external vertebral morphology, and is less consistent across individuals and species. The cervical region has the most distinct and consistent trabecular bone morphology, with dense trabeculae indicative of the ability to withstand forces in a variety of directions. Scutisorex exhibits an additional external morphology region compared to unmodified shrews, but this region does not correspond to a change in trabecular architecture. Although trabecular bone architecture is regionalized along the soricid vertebral column, and this regionalization is potentially related to bone functional adaptation, there are likely aspects of vertebral functional regionalization that are not detectable using trabecular bone morphology. For example, the external morphology of the Scutisorex lumbar spine shows signs of an extra functional region that is not apparent in trabecular bone analyses. It is possible that body size and locomotor mode affect the degree to which function is manifest in trabecular bone, and broader study across mammalian size and ecology is warranted to understand the relationship between trabecular bone morphology and other measures of vertebral function such as intervertebral range of motion.
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Affiliation(s)
- Stephanie M Smith
- Field Museum of Natural History, Negaunee Integrative Research Center, 1400 S DuSable Lake Shore Drive, Chicago IL 60605, USA
| | - Kenneth D Angielczyk
- Field Museum of Natural History, Negaunee Integrative Research Center, 1400 S DuSable Lake Shore Drive, Chicago IL 60605, USA
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30
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Day GA, Jones AC, Wilcox RK. Using Statistical Shape and Appearance Modelling to characterise the 3D shape and material properties of human lumbar vertebrae: A proof of concept study. J Mech Behav Biomed Mater 2022; 126:105047. [PMID: 34999487 DOI: 10.1016/j.jmbbm.2021.105047] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 12/08/2021] [Accepted: 12/11/2021] [Indexed: 10/19/2022]
Abstract
Patient variation affects the outcomes of a range of spinal interventions, from disc replacement to vertebral fixation and vertebroplasty. Statistical Shape and Appearance Modelling (SSAM) can be used to describe anatomical variation and pathological differences within the population. To better understand how bone density and shape variation affect load transfer with respect to surgical treatments, Finite Element (FE) models can be generated from a SSAM. The aim for this study is to understand whether geometric and density variation as well as multiple vertebral levels can be incorporated into a single SSAM and whether this can be used to investigate the relationships between, and effects of, the various modes of variation. FE models of 14 human lumbar vertebrae that had been μCT imaged and validated through experimental testing were used as input specimens for a SSAM. The validity of the SSAM was evaluated by using principal component analysis to identify the primary modes of geometric and bone density variation and comparing to those in the input set. FE models were generated from the SSAM to examine the response to loading. The mean error between the input set and generated models for volume, mean density and FE compressive stiffness were 10%, 3% and 10% respectively. Principal Component (PC) 1 captured the majority of the bone density variation. The remaining PCs described specific geometric variation. The FE models generated from the SSAM showed the variations in vertebral stiffness as a result of complex relationships between bone density and shape. The SSAM created has limited data for its input set, however, it acts as a proof of concept for the novel combination of material and shape variation into a single shape model. This approach and the tools developed can be applied to wider patient groups and treatment scenarios to improve patient stratification and to optimise treatments.
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Affiliation(s)
- G A Day
- Institute of Medical and Biological Engineering, Mechanical Engineering, University of Leeds, UK.
| | - A C Jones
- Institute of Medical and Biological Engineering, Mechanical Engineering, University of Leeds, UK
| | - R K Wilcox
- Institute of Medical and Biological Engineering, Mechanical Engineering, University of Leeds, UK
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31
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Brown JP, Engelke K, Keaveny TM, Chines A, Chapurlat R, Foldes AJ, Nogues X, Civitelli R, De Villiers T, Massari F, Zerbini CAF, Wang Z, Oates MK, Recknor C, Libanati C. Romosozumab improves lumbar spine bone mass and bone strength parameters relative to alendronate in postmenopausal women: results from the Active-Controlled Fracture Study in Postmenopausal Women With Osteoporosis at High Risk (ARCH) trial. J Bone Miner Res 2021; 36:2139-2152. [PMID: 34190361 PMCID: PMC9292813 DOI: 10.1002/jbmr.4409] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 06/16/2021] [Accepted: 06/25/2021] [Indexed: 01/20/2023]
Abstract
The Active-Controlled Fracture Study in Postmenopausal Women With Osteoporosis at High Risk (ARCH) trial (NCT01631214; https://clinicaltrials.gov/ct2/show/NCT01631214) showed that romosozumab for 1 year followed by alendronate led to larger areal bone mineral density (aBMD) gains and superior fracture risk reduction versus alendronate alone. aBMD correlates with bone strength but does not capture all determinants of bone strength that might be differentially affected by various osteoporosis therapeutic agents. We therefore used quantitative computed tomography (QCT) and finite element analysis (FEA) to assess changes in lumbar spine volumetric bone mineral density (vBMD), bone volume, bone mineral content (BMC), and bone strength with romosozumab versus alendronate in a subset of ARCH patients. In ARCH, 4093 postmenopausal women with severe osteoporosis received monthly romosozumab 210 mg sc or weekly oral alendronate 70 mg for 12 months, followed by open-label weekly oral alendronate 70 mg for ≥12 months. Of these, 90 (49 romosozumab, 41 alendronate) enrolled in the QCT/FEA imaging substudy. QCT scans at baseline and at months 6, 12, and 24 were assessed to determine changes in integral (total), cortical, and trabecular lumbar spine vBMD and corresponding bone strength by FEA. Additional outcomes assessed include changes in aBMD, bone volume, and BMC. Romosozumab caused greater gains in lumbar spine integral, cortical, and trabecular vBMD and BMC than alendronate at months 6 and 12, with the greater gains maintained upon transition to alendronate through month 24. These improvements were accompanied by significantly greater increases in FEA bone strength (p < 0.001 at all time points). Most newly formed bone was accrued in the cortical compartment, with romosozumab showing larger absolute BMC gains than alendronate (p < 0.001 at all time points). In conclusion, romosozumab significantly improved bone mass and bone strength parameters at the lumbar spine compared with alendronate. These results are consistent with greater vertebral fracture risk reduction observed with romosozumab versus alendronate in ARCH and provide insights into structural determinants of this differential treatment effect. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Jacques P Brown
- Centre Hospitalier Universitaire (CHU) de Québec Research Centre, Department of Medicine, Rheumatology Division, Laval University, Quebec City, Québec, Canada
| | - Klaus Engelke
- Bioclinica, Hamburg, Germany.,Department of Medicine 3, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany
| | - Tony M Keaveny
- Departments of Mechanical Engineering and Bioengineering, University of California Berkeley, Berkeley, California, USA
| | | | - Roland Chapurlat
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unités Mixtes de Recherche (UMR) 1033, Université de Lyon, Hôpital E Herriot, Lyon, France
| | - A Joseph Foldes
- Osteoporosis Center, Hadassah Hebrew University Medical Center, Jerusalem, Israel
| | - Xavier Nogues
- Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Centro de Investigación Biomédica en Red Fragilidad y Envejecimiento Saludable (CIBERFES), Autonomous University of Barcelona, Barcelona, Spain
| | - Roberto Civitelli
- Musculoskeletal Research Center, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Tobias De Villiers
- Department of Obstetrics and Gynaecology, Stellenbosch University, Stellenbosch, South Africa
| | - Fabio Massari
- Instituto de Diagnóstico e Investigaciones Metabólicas, Buenos Aires, Argentina
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The Role of Vertebral Porosity and Implant Loading Mode on Bone-Tissue Stress in the Human Vertebral Body Following Lumbar Total Disc Arthroplasty. Spine (Phila Pa 1976) 2021; 46:E1022-E1030. [PMID: 33660678 DOI: 10.1097/brs.0000000000004023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Micro-computed tomography- (micro-CT-) based finite element analysis of cadaveric human lumbar vertebrae virtually implanted with total disc arthroplasty (TDA) implants. OBJECTIVE (1) Assess the relationship between vertebral porosity and maximum levels of bone-tissue stress following TDA; (2) determine whether the implant's loading mode (axial compression vs. sagittal bending) alters the relationship between vertebral porosity and bone-tissue stress. SUMMARY OF BACKGROUND DATA Implant subsidence may be related to the bone biomechanics in the underlying vertebral body, which are poorly understood. For example, it remains unclear how the stresses that develop in the supporting bone tissue depend on the implant's loading mode or on typical inter-individual variations in vertebral morphology. METHODS Data from micro-CT scans from 12 human lumbar vertebrae (8 males, 4 females; 51-89 years of age; bone volume fraction [BV/TV] = 0.060-0.145) were used to construct high-resolution finite element models (37 μm element edge length) comprising disc-vertebra-implant motion segments. Implants were loaded to 800 N of force in axial compression, flexion-, and extension-induced impingement. For comparison, the same net loads were applied via an intact disc without an implant. Linear regression was used to assess the relationship between BV/TV, loading mode, and the specimen-specific change in stress caused by implantation. RESULTS The increase in maximum bone-tissue stress caused by implantation depended on loading mode (P < 0.001), increasing more in bending-induced impingement than axial compression (for the same applied force). The change in maximum stress was significantly associated with BV/TV (P = 0.002): higher porosity vertebrae experienced a disproportionate increase in stress compared with lower porosity vertebrae. There was a significant interaction between loading mode and BV/TV (P = 0.002), indicating that loading mode altered the relationship between BV/TV and the change in maximum bone-tissue stress. CONCLUSION Typically-sized TDA implants disproportionately increase the bone-tissue stress in more porous vertebrae; this affect is accentuated when the implant impinges in sagittal bending.Level of Evidence: N/A.
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Palanca M, Barbanti-Bròdano G, Marras D, Marciante M, Serra M, Gasbarrini A, Dall'Ara E, Cristofolini L. Type, size, and position of metastatic lesions explain the deformation of the vertebrae under complex loading conditions. Bone 2021; 151:116028. [PMID: 34087385 DOI: 10.1016/j.bone.2021.116028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/14/2021] [Accepted: 05/29/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Bone metastases may lead to spine instability and increase the risk of fracture. Scoring systems are available to assess critical metastases, but they lack specificity, and provide uncertain indications over a wide range, where most cases fall. The aim of this work was to use a novel biomechanical approach to evaluate the effect of lesion type, size, and location on the deformation of the metastatic vertebra. METHOD Vertebrae with metastases were identified from 16 human spines from a donation programme. The size and position of the metastases, and the Spine Instability Neoplastic Score (SINS) were evaluated from clinical Quantitative Computed Tomography images. Thirty-five spine segments consisting of metastatic vertebrae and adjacent healthy controls were biomechanically tested in four different loading conditions. The strain distribution over the entire vertebral bodies was measured with Digital Image Correlation. Correlations between the features of the metastasis (type, size, position and SINS) and the deformation of the metastatic vertebrae were statistically explored. RESULTS The metastatic type (lytic, blastic, mixed) characterizes the vertebral behaviour (Kruskal-Wallis, p = 0.04). In fact, the lytic metastases showed more critical deformation compared to the control vertebrae (average: 2-fold increase, with peaks of 14-fold increase). By contrast, the vertebrae with mixed or blastic metastases did not show a clear trend, with deformations similar or lower than the controls. Once the position of the lytic lesion with respect to the loading direction was taken into account, the size of the lesion was significantly correlated with the perturbation to the strain distribution (r2 = 0.72, p < 0.001). Conversely, the SINS poorly correlated with the mechanical evidence, and only in case of lytic lesions (r2 = 0.25, p < 0.0001). CONCLUSION These results highlight the relevance of the size and location of the lytic lesion, which are marginally considered in the current clinical scoring systems, in driving the spinal biomechanical instability. The strong correlation with the biomechanical evidence indicates that these parameters are representative of the mechanical competence of the vertebra. The improved explanatory power compared to the SINS suggests including them in future guidelines for the clinical practice.
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Affiliation(s)
- Marco Palanca
- Dept of Oncology and Metabolism, INSIGNEO Institute for In Silico Medicine, University of Sheffield, Sheffield, UK; Dept of Industrial Engineering, Alma Mater Studiorum - University of Bologna, Bologna, Italy.
| | | | - Daniele Marras
- Dept of Industrial Engineering, Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | - Mara Marciante
- Dept of Industrial Engineering, Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | - Michele Serra
- Dept of Industrial Engineering, Alma Mater Studiorum - University of Bologna, Bologna, Italy
| | | | - Enrico Dall'Ara
- Dept of Oncology and Metabolism, INSIGNEO Institute for In Silico Medicine, University of Sheffield, Sheffield, UK
| | - Luca Cristofolini
- Dept of Industrial Engineering, Alma Mater Studiorum - University of Bologna, Bologna, Italy
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Do XN, Hambli R, Ganghoffer JF. Mesh-independent damage model for trabecular bone fracture simulation and experimental validation. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2021; 37:e3468. [PMID: 33896124 DOI: 10.1002/cnm.3468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 06/12/2023]
Abstract
We propose in this study a two-dimensional constitutive model for trabecular bone combining continuum damage with embedded strong discontinuity. The model is capable of describing the three failure phases of trabecular bone tissue which is considered herein as a quasi-brittle material with strains and rotations assumed to be small and without viscous, thermal or other non-mechanical effects. The finite element implementation of the present model uses constant strain triangle (CST) elements. The displacement jump vector is implicitly solved through a return mapping algorithm at the local (finite element) level, while the global equilibrium equations are dealt with by Newton-Raphson method. The performance, accuracy and applicability of the proposed model for trabecular bone fracture are evaluated and validated against experimental measurements. These comparisons include both global and local aspects through numerical simulations of three-point bending tests performed on 10 single bovine trabeculae in the quasi-static regime.
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Affiliation(s)
- Xuan Nam Do
- LEM3, Université de Lorraine - CNRS - Arts et Métiers Paristech, Metz Cedex, France
| | - Ridha Hambli
- INSA CVL, LaMé, Université d'Orléans, Université de Tours, Orléans, France
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Palanca M, De Donno G, Dall’Ara E. A novel approach to evaluate the effects of artificial bone focal lesion on the three-dimensional strain distributions within the vertebral body. PLoS One 2021; 16:e0251873. [PMID: 34061879 PMCID: PMC8168867 DOI: 10.1371/journal.pone.0251873] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 05/05/2021] [Indexed: 12/14/2022] Open
Abstract
The spine is the first site for incidence of bone metastasis. Thus, the vertebrae have a high potential risk of being weakened by metastatic tissues. The evaluation of strength of the bone affected by the presence of metastases is fundamental to assess the fracture risk. This work proposes a robust method to evaluate the variations of strain distributions due to artificial lesions within the vertebral body, based on in situ mechanical testing and digital volume correlation. Five porcine vertebrae were tested in compression up to 6500N inside a micro computed tomography scanner. For each specimen, images were acquired before and after the application of the load, before and after the introduction of the artificial lesions. Principal strains were computed within the bone by means of digital volume correlation (DVC). All intact specimens showed a consistent strain distribution, with peak minimum principal strain in the range -1.8% to -0.7% in the middle of the vertebra, demonstrating the robustness of the method. Similar distributions of strains were found for the intact vertebrae in the different regions. The artificial lesion generally doubled the strain in the middle portion of the specimen, probably due to stress concentrations close to the defect. In conclusion, a robust method to evaluate the redistribution of the strain due to artificial lesions within the vertebral body was developed and will be used in the future to improve current clinical assessment of fracture risk in metastatic spines.
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Affiliation(s)
- Marco Palanca
- Dept of Oncology and Metabolism and INSIGNEO Institute for in silico Medicine, The University of Sheffield, Sheffield, United Kingdom
| | - Giulia De Donno
- Dept of Oncology and Metabolism and INSIGNEO Institute for in silico Medicine, The University of Sheffield, Sheffield, United Kingdom
- Dept of Industrial Engineering, Alma Mater Studiorum, Università di Bologna, Bologna, Italy
| | - Enrico Dall’Ara
- Dept of Oncology and Metabolism and INSIGNEO Institute for in silico Medicine, The University of Sheffield, Sheffield, United Kingdom
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Amson E, Bibi F. Differing effects of size and lifestyle on bone structure in mammals. BMC Biol 2021; 19:87. [PMID: 33926429 PMCID: PMC8086358 DOI: 10.1186/s12915-021-01016-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 04/01/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mammals are a highly diverse group, with body mass ranging from 2 g to 170 t, and encompassing species with terrestrial, aquatic, aerial, and subterranean lifestyles. The skeleton is involved in most aspects of vertebrate life history, but while previous macroevolutionary analyses have shown that structural, phylogenetic, and functional factors influence the gross morphology of skeletal elements, their inner structure has received comparatively little attention. Here we analysed bone structure of the humerus and mid-lumbar vertebrae across mammals and their correlations with different lifestyles and body size. RESULTS We acquired bone structure parameters in appendicular and axial elements (humerus and mid-lumbar vertebra) from 190 species across therian mammals (placentals + marsupials). Our sample captures all transitions to aerial, fully aquatic, and subterranean lifestyles in extant therian clades. We found that mammalian bone structure is highly disparate and we show that the investigated vertebral structure parameters mostly correlate with body size, but not lifestyle, while the opposite is true for humeral parameters. The latter also show a high degree of convergence among the clades that have acquired specialised (non-terrestrial) lifestyles. CONCLUSIONS In light of phylogenetic, size, and functional factors, the distribution of each investigated structural parameter reveals patterns explaining the construction of appendicular and axial skeletal elements in mammalian species spanning most of the extant diversity of the clade in terms of body size and lifestyle. These patterns should be further investigated with analyses focused on specific lifestyle transitions that would ideally include key fossils.
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Affiliation(s)
- Eli Amson
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115, Berlin, Germany.
- Staatliches Museum für Naturkunde Stuttgart, Rosenstein 1, 70191, Stuttgart, Germany.
| | - Faysal Bibi
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115, Berlin, Germany
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Ma C, Wu F, Pan F, Laslett L, Shah A, Squibb K, Winzenberg T, Jones G. Bone Microarchitecture, Volumetric or Areal Bone Mineral Density for Discrimination of Vertebral Deformity in Adults: A Cross-sectional Study. J Clin Densitom 2021; 24:190-199. [PMID: 32586682 DOI: 10.1016/j.jocd.2020.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 05/02/2020] [Accepted: 05/05/2020] [Indexed: 11/24/2022]
Abstract
INTRODUCTION/BACKGROUND Both areal bone mineral density (aBMD) and bone microarchitecture have been associated with vertebral deformity (VD), but there are limited data on the utility of bone microarchitecture measures in combination with aBMD in discriminating VD. This study aimed to describe whether radial bone microarchitecture measures alone or in combinations with radial volumetric bone mineral density (vBMD) or spine aBMD can improve discrimination of VD in adults. METHODS Data on 196 subjects (mean age (standard deviation, SD) = 72 (7) years, female 46%) were utilized. VD of T4-L4 and spine aBMD were measured using dual-energy X-ray absorptiometry. VD was defined if anterior to posterior height ratio was more than 3-SD, 4-SD below, or >25% decrease compared with the sex-matched normal means. Bone microarchitecture parameters at distal radius were collected using high-resolution peripheral quantitative computed tomography and analyzed using StrAx. RESULTS The strongest associations were seen for the cortical thickness (odds ratios (ORs): 2.63/SD decrease for 25% and 2.38/SD decrease for 3-SD criterion) and compact cortical area (OR: 3.33/SD decrease for 4-SD criterion). The area under the receiver operating characteristic curve (AUC) for spine aBMD for VD was 0.594, 0.597, and 0.634 for 25%, 3-SD and 4-SD criteria, respectively (all p < 0.05). Compact cortical area, cortical thickness and compact cortical thickness alone had the largest AUCs for VD (0.680-0.685 for 25% criterion, 0.659-0.674 for 3-SD criterion, and 0.699-0.707 for 4-SD criterion). Adding spine aBMD or radial vBMD to each cortical measure did not improve VD discrimination (∆ AUC 0.8%-2.1%). CONCLUSIONS Cortical measures had the best utility for discriminating VD when used alone. Adding either spine aBMD or radial vBMD did not improve the utility of cortical measures.
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Affiliation(s)
- Canchen Ma
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Feitong Wu
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Feng Pan
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Laura Laslett
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Anuj Shah
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Kathryn Squibb
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Tania Winzenberg
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia
| | - Graeme Jones
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia.
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Fluid-structure interaction (FSI) modeling of bone marrow through trabecular bone structure under compression. Biomech Model Mechanobiol 2021; 20:957-968. [PMID: 33547975 DOI: 10.1007/s10237-021-01423-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 01/10/2021] [Indexed: 10/22/2022]
Abstract
The present study has sought to investigate the fluid characteristic and mechanical properties of trabecular bone using fluid-structure interaction (FSI) approach under different trabecular bone orientations. This method imposed on trabecular bone structure at both longitudinal and transverse orientations to identify effects on shear stress, permeability, stiffness and stress regarded to the trabeculae. Sixteen FSI models were performed on different range trabecular cubes of 27 mm3 with eight models developed for each longitudinal and transverse direction. Results show that there was a moderate correlation between permeability and porosity, and surface area in the longitudinal and transverse orientations. For the longitudinal orientation, the permeability values varied between 3.66 × 10-8 and 1.9 × 10-7 and the sheer stress values varied between 0.05 and 1.8 Pa, whilst for the transverse orientation, the permeability values varied between 5.95 × 10-10 and 1.78 × 10-8 and the shear stress values varied between 0.04 and 3.1 Pa. Here, transverse orientation limits the fluid flow from passing through the trabeculae due to high shear stress disturbance generated within the trabecular bone region. Compared to physiological loading direction (longitudinal orientation), permeability is higher within the range known to trigger a response in bone cells. Additionally, shear stresses also increase with bone surface area. This study suggests the shear stress within bone marrow in real trabecular architecture could provide the mechanical signal to marrow cells that leads to bone anabolism and can depend on trabecular orientation.
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Losch MS, Swamy A, Elmi-Terander A, Edström E, Hendriks BHW, Dankelman J. Proton density fat fraction of the spinal column: an MRI cadaver study. Biomed Eng Online 2021; 20:7. [PMID: 33413458 PMCID: PMC7792224 DOI: 10.1186/s12938-020-00846-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 12/28/2020] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The increased popularity of minimally invasive spinal surgery calls for a revision of guidance techniques to prevent injuries of nearby neural and vascular structures. Lipid content has previously been proposed as a distinguishing criterion for different bone tissues to provide guidance along the interface of cancellous and cortical bone. This study aims to investigate how fat is distributed throughout the spinal column to confirm or refute the suitability of lipid content for guidance purposes. RESULTS Proton density fat fraction (PDFF) was assessed over all vertebral levels for six human cadavers between 53 and 92 years of age, based on fat and water MR images. According to their distance to the vertebra contour, the data points were grouped in five regions of interest (ROIs): cortical bone (-1 mm to 0 mm), pre-cortical zone (PCZ) 1-3 (0-1 mm; 1-2 mm; 2-3 mm), and cancellous bone ([Formula: see text] 3 mm). For PCZ1 vs. PCZ2, a significant difference in mean PDFF of between -7.59 pp and -4.39 pp on average was found. For cortical bone vs. PCZ1, a significant difference in mean PDFF of between -27.09 pp and -18.96 pp on average was found. CONCLUSION A relationship between distance from the cortical bone boundary and lipid content could be established, paving the way for guidance techniques based on fat fraction detection for spinal surgery.
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Affiliation(s)
- Merle S. Losch
- Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands
| | - Akash Swamy
- Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands
- Department of In-Body Systems, Philips Research, Royal Philips, NV Eindhoven, The Netherlands
| | - Adrian Elmi-Terander
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Neurosurgery, Karolinska University Hospital, Stockholm, Sweden
| | - Erik Edström
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Neurosurgery, Karolinska University Hospital, Stockholm, Sweden
| | - Benno H. W. Hendriks
- Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands
- Department of In-Body Systems, Philips Research, Royal Philips, NV Eindhoven, The Netherlands
| | - Jenny Dankelman
- Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands
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Stipsitz M, Zysset PK, Pahr DH. Prediction of the Inelastic Behaviour of Radius Segments: Damage-based Nonlinear Micro Finite Element Simulation vs Pistoia Criterion. J Biomech 2021; 116:110205. [PMID: 33476984 DOI: 10.1016/j.jbiomech.2020.110205] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 12/08/2020] [Accepted: 12/12/2020] [Indexed: 10/22/2022]
Abstract
The Pistoia criterion (PC) is widely used to estimate the failure load of distal radius segments based on linear micro Finite Element (μFE) analyses. The advantage of the PC is that a simple strain-threshold and a tissue volume fraction can be used to predict failure properties. In this study, the PC is compared to materially nonlinear μFE analyses, where the bone tissue is modelled as an elastic, damageable material. The goal was to investigate for which outcomes the PC is sufficient and when a nonlinear (NL) simulation is required. Three types of simulation results were compared: (1) prediction of the failure load, (2) load sharing of cortical and trabecular regions, and (3) distribution of local damaged/overstrained tissue at the maximum sustainable load. The failure load obtained experimentally could be predicted well with both the PC and the NL simulations using linear regression. Although the PC strongly overestimated the failure load, it was sufficient to predict adequately normalized apparent results. An optimised PC (oPC) was proposed which uses experimental data to calibrate the individual volume of overstrained tissue. The main areas of local over-straining predicted by the oPC were the same as estimated by the NL simulation, although the oPC predicted more diffuse regions. However, the oPC relied on an individual calibration requiring the experimental failure load while the NL simulation required no a priori knowledge of the experimental failure load.
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Affiliation(s)
- Monika Stipsitz
- Institute of Lightweight Design and Structural Biomechanics, TU Wien, Austria
| | - Philippe K Zysset
- ARTORG Center for Biomedical Engineering Research, University of Bern, Switzerland
| | - Dieter H Pahr
- Institute of Lightweight Design and Structural Biomechanics, TU Wien, Austria; Division Biomechanics, Karl Landsteiner University, Austria
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Ely EV, Osipov B, Emami AJ, Christiansen BA. Region-dependent bone loss in the lumbar spine following femoral fracture in mice. Bone 2020; 140:115555. [PMID: 32736144 PMCID: PMC7502487 DOI: 10.1016/j.bone.2020.115555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 07/03/2020] [Accepted: 07/14/2020] [Indexed: 10/23/2022]
Abstract
We previously showed that after femur fracture, mice lose bone at distant skeletal sites, including the lumbar vertebrae. This bone loss may increase the risk of subsequent vertebral fractures, particularly if bone is lost from high-strain bone regions, which are most commonly found adjacent to the superior and inferior endplates of the vertebral body. To determine regional bone loss from the lumbar spine following femur fracture, we evaluated the cranial, center, and caudal portions of the L5 vertebral bodies of Young (3 month-old) and Middle-Aged (12 month-old) female C57BL/6 mice two weeks after a transverse femur fractures compared to Young and Middle-Aged uninjured control mice. We hypothesized that greater bone loss would be observed in the cranial and caudal regions than in the center region in both Young and Middle-Aged mice. Trabecular and cortical bone microstructure were evaluated using micro-computed tomography, and osteoclast number and eroded surface were evaluated histologically. In Young Mice, fracture led to decreased trabecular and cortical bone microstructure primarily in the cranial and caudal regions, but not the center region, while Middle-Aged mice demonstrated decreases in trabecular bone in all regions, but did not exhibit any changes in cortical bone microstructure after fracture. No significant differences in osteoclast number or eroded surface were observed at this time point. These data suggest that bone loss following fracture in Young Mice is concentrated in areas that contain a large amount of high-strain tissue, whereas bone loss in Middle-Aged mice is less region-dependent and is restricted to the trabecular bone compartment. These results illustrate how systemic bone loss after fracture could lead to decreases in vertebral strength, and how distinct regional patterns and age-dependent differences in bone loss may differentially affect vertebral fracture risk.
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Affiliation(s)
- Erica V Ely
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States of America.
| | - Benjamin Osipov
- Department of Orthopaedic Surgery, University of California Davis Health, Sacramento, CA, United States of America.
| | - Armaun J Emami
- Department of Orthopaedic Surgery, University of California Davis Health, Sacramento, CA, United States of America.
| | - Blaine A Christiansen
- Department of Orthopaedic Surgery, University of California Davis Health, Sacramento, CA, United States of America.
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Distribution of Young's modulus at various sampling points in a human lumbar spine vertebral body. Spine J 2020; 20:1861-1875. [PMID: 32592901 DOI: 10.1016/j.spinee.2020.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/17/2020] [Accepted: 06/17/2020] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Mathematical modeling for creating computer spine models is one of the basic methods underlying many scientific publications. The accuracy of strength parameters of tissues introduced into such models translates directly into the reliability of obtained results. Experimental determination of Young's modulus (E) in various areas of spongy bone tissue seems to be crucial for creating a reliable spine model without excessive simplifications in the form of a single E value for the whole vertebral body. PURPOSE The aim of the study was to determine Young's modulus in different parts of the lumbar vertebral column for samples subjected to compression and bending. STUDY DESIGN Cylindrical spongy bone tissue samples were subjected to bending and compression strength tests. METHODS The study included 975 pathologically unchanged samples of spongy bone tissue harvested from the lumbar vertebrae of 15 male donors. The samples were subjected to compression or bending strength tests and then Young's modulus was determined for each sample depending on its location in the vertebral body. The samples were tested differently between given locations within one vertebra as well as between vertebrae. RESULTS Compressed specimens are characterized by highly significantly different Young's modulus values depending on the location in the vertebral body. Samples No. 7 and No. 9 in the anterior part of the vertebral body have highly significantly higher Young's modulus values compared to those in the posterior part of the vertebral body for all lumbar vertebrae. Samples subjected to bending showed significant differences (p<.05) between samples located closer to the vertebral canal (No.16, No.17) and samples located further away (No.14, No.15) with higher values for the samples located in the posterior part of the vertebral body. CONCLUSIONS Accommodating the anisotropic structure of spongy bone in computer models and the application of different Young's module values for areas within one vertebral body will allow one to obtain realistic results of computer simulations used. CLINICAL SIGNIFICANCE Determining the exact strength parameters of spongy bone tissue within one vertebra and changes in these properties in subsequent vertebrae will allow to create more accurate computer models of the lumbar spine and the whole spine. This, in turn, will translate into more reliable computer simulations used, among others, to determine the risk of fractures or osteoporotic changes, or simulation of the procedure of spinal fusion.
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Sadoughi S, Vom Scheidt A, Nawathe S, Zhu S, Moini A, Keaveny TM. Effect of variations in tissue-level ductility on human vertebral strength. Bone 2020; 137:115445. [PMID: 32454256 DOI: 10.1016/j.bone.2020.115445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 05/17/2020] [Accepted: 05/19/2020] [Indexed: 11/28/2022]
Abstract
Although the ductility of bone tissue is a unique element of bone quality and varies with age and across the population, the extent to which and mechanisms by which typical population-variations in tissue-level ductility can alter whole-bone strength remains unclear. To provide insight, we conducted a finite element analysis parameter study of whole-vertebral (monotonic) compressive strength on six human L1 vertebrae. Each model was generated from micro-CT scans, capturing the trabecular micro-architecture in detail, and included a non-linear constitutive model for the bone tissue that allowed for plastic yielding, different strengths in tension and compression, large deformations, and, uniquely, localized damage once a specified limit in tissue-level ultimate strain was exceeded. Those strain limits were based on reported (mean ± SD) values from cadaver experiments (8.8 ± 3.7% strain for trabecular tissue and 2.2 ± 0.9% for cortical tissue). In the parameter study, the strain limits were varied by ±1 SD from their mean values, for a combination of nine analyses per specimen; bounding values of zero and unlimited post-yield strain were also modeled. The main outcomes from the finite element analysis were the vertebral compressive strength and the amount of failed (yielded or damaged) tissue at the overall structure-level failure. Compared to a reference case of using the mean values of ultimate strain, we found that varying both trabecular and cortical tissue ultimate strains by ±1 SD changed the computed vertebral strength by (mean ± SD) ±6.9 ± 1.1% on average. Mechanistically, that modest effect arose because the proportion of yielded tissue (without damage) was 0.9 ± 0.3% of all the bone tissue across the nine cases and the proportion of damaged tissue (i.e. tissue exceeding the prescribed tissue-level ultimate strain) was 0.2 ± 0.1%. If the types of variations in tissue-level ductility investigated here accurately represent real typical variations in the population, the consistency of our results across specimens and the modest effect size together suggest that typical variations in tissue-level ductility only have a modest impact on vertebral compressive strength, in large part because so few trabeculae are damaged at the load capacity of the bone.
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Affiliation(s)
- Saghi Sadoughi
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Annika Vom Scheidt
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA; Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Shashank Nawathe
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Shan Zhu
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Ariana Moini
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA
| | - Tony M Keaveny
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA; Department of Bioengineering, University of California, Berkeley, CA, USA.
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Steczina S, Tahimic CGT, Pendleton M, M'Saad O, Lowe M, Alwood JS, Halloran BP, Globus RK, Schreurs AS. Dietary countermeasure mitigates simulated spaceflight-induced osteopenia in mice. Sci Rep 2020; 10:6484. [PMID: 32300161 PMCID: PMC7162976 DOI: 10.1038/s41598-020-63404-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 02/26/2020] [Indexed: 02/06/2023] Open
Abstract
Spaceflight is a unique environment that includes at least two factors which can negatively impact skeletal health: microgravity and ionizing radiation. We have previously shown that a diet supplemented with dried plum powder (DP) prevented radiation-induced bone loss in mice. In this study, we investigated the capacity of the DP diet to prevent bone loss in mice following exposure to simulated spaceflight, combining microgravity (by hindlimb unloading) and radiation exposure. The DP diet was effective at preventing most decrements in bone micro-architectural and mechanical properties due to hindlimb unloading alone and simulated spaceflight. Furthermore, we show that the DP diet can protect osteoprogenitors from impairments resulting from simulated microgravity. Based on our findings, a dietary supplementation with DP could be an effective countermeasure against the skeletal deficits observed in astronauts during spaceflight.
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Affiliation(s)
- Sonette Steczina
- Blue Marble Space Institute of Science, Seattle, WA, 98154, USA.,Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Candice G T Tahimic
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA.,KBR, Moffett Field, California, USA
| | - Megan Pendleton
- Department of Mechanical Engineering, University of California, Berkeley, Berkeley, CA, 94720, USA
| | - Ons M'Saad
- Space Life Sciences Training Program, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Moniece Lowe
- Blue Marble Space Institute of Science, Seattle, WA, 98154, USA.,Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Joshua S Alwood
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Bernard P Halloran
- Department of Medicine, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Ruth K Globus
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Ann-Sofie Schreurs
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA. .,Universities Space Research Association, Moffett Field, CA, USA.
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45
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Dai C, Jia J, Kot A, Liu X, Liu L, Jiang M, Lane NE, Wise BL, Yao W. Selective inhibition of progesterone receptor in osteochondral progenitor cells, but not in mature chondrocytes, modulated subchondral bone structures. Bone 2020; 132:115196. [PMID: 31863959 PMCID: PMC7006606 DOI: 10.1016/j.bone.2019.115196] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 12/16/2019] [Accepted: 12/17/2019] [Indexed: 01/12/2023]
Abstract
OBJECTIVE The presence or relative proportion of progesterone nuclear receptors (PR) in different tissues may contribute to sexual dimorphism in these tissues. PR is expressed in chondrocytes, but its function is mostly unknown. We hypothesized that the PR may regulate chondrocyte metabolism and affect subchondral bone structure. METHODS We utilized genetic fate mapping and immunohistochemistry to elucidate PR expression in and effect on cartilage. To define sex-dependent and chondrocyte-specific effects of the PR on subchondral bone, we selectively deleted PR in osteochondrogenic progenitor cells marked by Prx1 (Prx1; PRcKO) and Collagen 2 (Col2; PRcKO), or in matured chondrocytes marked by aggrecan (Acan; PRcKO) and evaluated subchondral bone structure at 4 months of age. Chondrocyte aging was monitored by anti-senescence marker p16INK4a, and MMP13, one of the Senescence-Associated Secretary Phenotype (SASP) components. RESULTS Compared to wild-type (WT) mice, the female Prx1; PRcKO and the Col2; PRcKO mice had greater total subchondral bone volume and greater subchondral cortical bone thickness, with increased estimated subchondral bone stiffness and failure load in both female and male Col2; PRcKO mice. Moreover, Col2; PRcKO mice from both sexes had greater bone formation and bone strength at the femurs. In contrast, we did not observe any subchondral bone changes in Acan; PRcKO mice other than higher work-to-failure observed in the male Acan; PRcKO mice. Despite no detected difference in articular cartilage between the WT and the PR; chondrocyte conditional deletion mice, there were greater numbers of senescent chondrocytes and increased MMP13 expression, especially in the male mutant mice. CONCLUSION These findings suggest that selective inhibition of PR in osteoprogenitor cells, but not in terminally differentiated chondrocytes, induced an increased subchondral bone phenotype and high estimated subchondral bone strength, which might be associated with the development of osteoarthritis in older age.
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Affiliation(s)
- Chenlin Dai
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California, Davis Medical Center, Sacramento, CA 95817, USA
| | - Junjing Jia
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California, Davis Medical Center, Sacramento, CA 95817, USA
| | - Alexander Kot
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California, Davis Medical Center, Sacramento, CA 95817, USA
| | - Xueping Liu
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California, Davis Medical Center, Sacramento, CA 95817, USA
| | - Lixian Liu
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California, Davis Medical Center, Sacramento, CA 95817, USA
| | - Min Jiang
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California, Davis Medical Center, Sacramento, CA 95817, USA
| | - Nancy E Lane
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California, Davis Medical Center, Sacramento, CA 95817, USA
| | - Barton L Wise
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California, Davis Medical Center, Sacramento, CA 95817, USA; Department of Orthopaedic Surgery, University of California, Davis Medical Center, Sacramento, CA 95817, USA
| | - Wei Yao
- Center for Musculoskeletal Health, Department of Internal Medicine, University of California, Davis Medical Center, Sacramento, CA 95817, USA.
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Bonnheim NB, Keaveny TM. Load-transfer in the human vertebral body following lumbar total disc arthroplasty: Effects of implant size and stiffness in axial compression and forward flexion. JOR Spine 2020; 3:e1078. [PMID: 32211590 PMCID: PMC7084059 DOI: 10.1002/jsp2.1078] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 11/07/2022] Open
Abstract
Adverse clinical outcomes for total disc arthroplasty (TDA), including subsidence, heterotopic ossification, and adjacent-level vertebral fracture, suggest problems with the underlying biomechanics. To gain insight, we investigated the role of size and stiffness of TDA implants on load-transfer within a vertebral body. Uniquely, we accounted for the realistic multi-scale geometric features of the trabecular micro-architecture and cortical shell. Using voxel-based finite element analysis derived from a micro-computed tomography scan of one human L1 vertebral body (74-μm-sized elements), a series of generic elliptically shaped implants were analyzed. We parametrically modeled three implant sizes (small, medium [a typical clinical size], and large) and three implant materials (metallic, E = 100 GPa; polymeric, E = 1 GPa; and tissue-engineered, E = 0.01 GPa). Analyses were run for two load cases: 800 N in uniform compression and flexion-induced anterior impingement. Results were compared to those of an intact model without an implant and loaded instead via a disc-like material. We found that TDA implantation increased stress in the bone tissue by over 50% in large portions of the vertebra. These changes depended more on implant size than material, and there was an interaction between implant size and loading condition. For the small implant, flexion increased the 98th-percentile of stress by 32 ± 24% relative to compression, but the overall stress distribution and trabecular-cortical load-sharing were relatively insensitive to loading mode. In contrast, for the medium and large implants, flexion increased the 98th-percentile of stress by 42 ± 9% and 87 ± 29%, respectively, and substantially re-distributed stress within the vertebra; in particular overloading the anterior trabecular centrum and cortex. We conclude that TDA implants can substantially alter stress deep within the lumbar vertebra, depending primarily on implant size. For implants of typical clinical size, bending-induced impingement can substantially increase stress in local regions and may therefore be one factor driving subsidence in vivo.
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Affiliation(s)
- Noah B. Bonnheim
- Department of Mechanical EngineeringUniversity of CaliforniaBerkeleyCalifornia
| | - Tony M. Keaveny
- Department of Mechanical EngineeringUniversity of CaliforniaBerkeleyCalifornia
- Department of BioengineeringUniversity of CaliforniaBerkeleyCalifornia
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47
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Burkhart K, Allaire B, Anderson DE, Lee D, Keaveny TM, Bouxsein ML. Effects of Long-Duration Spaceflight on Vertebral Strength and Risk of Spine Fracture. J Bone Miner Res 2020; 35:269-276. [PMID: 31670861 DOI: 10.1002/jbmr.3881] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 09/12/2019] [Accepted: 09/15/2019] [Indexed: 12/18/2022]
Abstract
Although the negative impact of long-duration spaceflight on spine BMD has been reported, its impact on vertebral strength and risk of vertebral fracture remains unknown. This study examined 17 crewmembers with long-duration service on the International Space Station in whom computed tomography (CT) scans of the lumbar spine (L1 and L2 ) were collected preflight, immediately postflight and 1 to 4 years after return to Earth. We assessed vertebral strength via CT-based finite element analysis (CT-FEA) and spinal loading during different activities via subject-specific musculoskeletal models. Six months of spaceflight reduced vertebral strength by 6.1% (-2.3%, -8.7%) (median [interquartile range]) compared to preflight (p < 0.05), with 65% of subjects experiencing deficits of greater than 5%, and strengths were not recovered up to 4 years after the mission. This decline in vertebral strength exceeded (p < 0.05) the 2.2% (-1.3%, -6.0%) decline in lumbar spine DXA-BMD. Further, the subject-specific changes in vertebral strength were not correlated with the changes in DXA-BMD. Although spinal loading increased slightly postflight, the ratio of vertebral compressive load to vertebral strength for typical daily activities remained well below a value of 1.0, indicating a low risk of vertebral fracture despite the loss in vertebral strength. However, for more strenuous activity, the postflight load-to-strength ratios ranged from 0.3 to 0.7, indicating a moderate risk of vertebral fracture in some individuals. Our findings suggest persistent deficits in vertebral strength following long-duration spaceflight, and although risk of vertebral fracture remains low for typical activities, the risk of vertebral fracture is notable in some crewmembers for strenuous exercise requiring maximal effort. © 2019 American Society for Bone and Mineral Research.
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Affiliation(s)
- Katelyn Burkhart
- Harvard-MIT Health Sciences and Technology Program, Massachusetts Institute of Technology, Cambridge, MA, USA.,Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Brett Allaire
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Dennis E Anderson
- Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, USA.,Department of Orthopaedic Surgery, Harvard Medical School, Boston, MA, USA
| | | | - Tony M Keaveny
- Department of Mechanical Engineering, University of California, Berkeley, CA, USA.,Department of Bioengineering, University of California, Berkeley, CA, USA
| | - Mary L Bouxsein
- Harvard-MIT Health Sciences and Technology Program, Massachusetts Institute of Technology, Cambridge, MA, USA.,Center for Advanced Orthopaedic Studies, Beth Israel Deaconess Medical Center, Boston, MA, USA.,Department of Orthopaedic Surgery, Harvard Medical School, Boston, MA, USA
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48
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The appropriate hybrid surgical strategy in three-level cervical degenerative disc disease: a finite element analysis. J Orthop Surg Res 2019; 14:444. [PMID: 31842938 PMCID: PMC6915991 DOI: 10.1186/s13018-019-1502-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 11/28/2019] [Indexed: 11/10/2022] Open
Abstract
Objective The purpose of this FE study was to analyze the biomechanical characteristics of different HS strategies used in the treatment of three-level CDDD (one-level CDA and two-level ACDF). Methods We validated the FE model of an intact cervical spine established by transferring the data, collected by 3D CT scan, to the FE software ABAQUS and comparing these data with the data from published studies. Then, the FE model of hybrid surgery was reconstructed to analyze the range of motion (ROM), facet joint force, and stress distribution on an ultrahigh molecular weight polyethylene (UHMWPE) core. Results The current cervical FE model was able to measure the biomechanical changes in a follow-up hybrid surgery simulation. The total ROM of the cervical HS models was substantially decreased compared with the total ROM of the intact group, and the M2 (C3/4 ACDF, C4/5 CDA, and C5/6 ACDF) model had the closest total ROM to the intact group, but the facet joint force adjacent to the treatment levels showed very little difference among them. The stress distribution showed noticeable similarity: two flanks were observed in the center core, but the inlay of M2 was more vulnerable. Conclusions Through the comparison of ROM, the facet joint force after CDA, and the stress distribution of the prosthesis, we find that M2 model has a better theoretical outcome, especially in preserving the maximum total ROM.
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Wood Z, Lynn L, Nguyen JT, Black MA, Patel M, Barak MM. Are we crying Wolff? 3D printed replicas of trabecular bone structure demonstrate higher stiffness and strength during off-axis loading. Bone 2019; 127:635-645. [PMID: 31390534 PMCID: PMC6939675 DOI: 10.1016/j.bone.2019.08.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/01/2019] [Accepted: 08/02/2019] [Indexed: 11/18/2022]
Abstract
Roux's principle of bone functional adaptation postulates that bone tissue, and particularly trabecular bone tissue, responds to mechanical stimuli by adjusting (modeling) its architecture accordingly. Hence, it predicts that the new modeled trabecular structure is mechanically improved (stiffer and stronger) in line with the habitual in vivo loading direction. While previous studies found indirect evidence to support this theory, direct support was so far unattainable. This is attributed to the fact that each trabecular bone is unique, and that trabecular bone tissue tends to be damaged during mechanical testing. Consequently, a unique modeled trabecular structure can be mechanically tested only along one direction and a comparison to other directions for that specific structure is impossible. To address this issue, we have 3D printed 10 replicas of a trabecular structure from a sheep talus cropped along the 3 principal axes of the bone and in line with the principal direction of loading (denoted on-axis model). Next, we have rotated the same cropped trabecular structure in increments of 10° up to 90° to the bone principal direction of loading (denoted off-axis models) and printed 10 replicas of each off-axis model. Finally, all on-axis and off-axis 3D printed replicas were loaded in compression until failure and trabecular structure stiffness and strength were calculated. Contrary to our prediction, and conflicting with Roux's principle of bone functional adaptation, we found that a trabecular structure loaded off-axis tended to have higher stiffness and strength values when compared to the same trabecular structure loaded on-axis. These unexpected results may not disprove Roux's principle of bone functional adaptation, but they do imply that trabecular bone adaptation may serve additional purposes than simply optimizing bone structure to one principal loading scenario and this suggests that we still don't fully understand bone modeling in its entirety.
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Affiliation(s)
- Zach Wood
- Department of Biology, Winthrop University, Rock Hill, SC 29733, USA
| | - Lisa Lynn
- Department of Biology, Winthrop University, Rock Hill, SC 29733, USA
| | - Jack T Nguyen
- Department of Biology, Winthrop University, Rock Hill, SC 29733, USA
| | - Margaret A Black
- Department of Biology, Winthrop University, Rock Hill, SC 29733, USA
| | - Meha Patel
- Department of Biology, Winthrop University, Rock Hill, SC 29733, USA
| | - Meir M Barak
- Department of Biology, Winthrop University, Rock Hill, SC 29733, USA; Department of Veterinary Biomedical Sciences, College of Veterinary Medicine, Long Island University, Brookville, NY 11548, USA.
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50
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Hussein AI, Louzeiro DT, Unnikrishnan GU, Morgan EF. Differences in Trabecular Microarchitecture and Simplified Boundary Conditions Limit the Accuracy of Quantitative Computed Tomography-Based Finite Element Models of Vertebral Failure. J Biomech Eng 2019; 140:2665235. [PMID: 29196764 DOI: 10.1115/1.4038609] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Indexed: 11/08/2022]
Abstract
Vertebral fractures are common in the elderly, but efforts to reduce their incidence have been hampered by incomplete understanding of the failure processes that are involved. This study's goal was to elucidate failure processes in the lumbar vertebra and to assess the accuracy of quantitative computed tomography (QCT)-based finite element (FE) simulations of these processes. Following QCT scanning, spine segments (n = 27) consisting of L1 with adjacent intervertebral disks and neighboring endplates of T12 and L2 were compressed axially in a stepwise manner. A microcomputed tomography scan was performed at each loading step. The resulting time-lapse series of images was analyzed using digital volume correlation (DVC) to quantify deformations throughout the vertebral body. While some diversity among vertebrae was observed on how these deformations progressed, common features were large strains that developed progressively in the superior third and, concomitantly, in the midtransverse plane, in a manner that was associated with spatial variations in microstructural parameters such as connectivity density. Results of FE simulations corresponded qualitatively to the measured failure patterns when boundary conditions were derived from DVC displacements at the endplate. However, quantitative correspondence was often poor, particularly when boundary conditions were simplified to uniform compressive loading. These findings suggest that variations in trabecular microstructure are one cause of the differences in failure patterns among vertebrae and that both the lack of incorporation of these variations into QCT-based FE models and the oversimplification of boundary conditions limit the accuracy of these models in simulating vertebral failure.
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Affiliation(s)
- Amira I Hussein
- Department of Mechanical Engineering, Boston University, 110 Cummington Mall, Boston, MA 02215 e-mail:
| | - Daniel T Louzeiro
- Department of Mechanical Engineering, Boston University, Boston, MA 02215
| | | | - Elise F Morgan
- Department of Mechanical Engineering, Boston University, Boston, MA 02215
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