1
|
Ji C, Zhang L, Wang Y, Lin B, Bai X, Yun S, He B. The influence of different shaped osteocyte lacunae on microcrack initiation and propagation. Clin Biomech (Bristol, Avon) 2023; 108:106072. [PMID: 37611387 DOI: 10.1016/j.clinbiomech.2023.106072] [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: 04/28/2023] [Revised: 08/12/2023] [Accepted: 08/16/2023] [Indexed: 08/25/2023]
Abstract
BACKGROUND The morphology of osteocyte lacunae varies in bones of different ages and bone pathologies. Osteocyte lacunae can cause stress concentration and initiate microcracks. However, the influence of changes in osteocyte lacunar shape on microcrack is unknown. Therefore, the aim of this study was to determine the effects of osteocyte lacunae with different shapes on microcrack initiation and propagation. METHODS Osteon models containing osteocyte lacunae with different shapes were established. The progressive damage analysis method, based on computer simulations, was used to study the evolution of microdamage within the osteon, including the processes of intralaminar and interlaminar microdamage. FINDINGS Models with larger DoE values can effectively delay or prevent the formation of linear microcracks, which ensures high fracture toughness of cortical bone. It is subjected to stronger mechanical stimulation, making it more sensitive to loads. Models with smaller DoE values increase the load threshold for microdamage generation and reduces its impact on bone mechanical performance, making it less susceptible to microdamage than models with larger DoE values. INTERPRETATION These findings enhance the limited knowledge of the influence of the lacunar shape on microdamage and contribute to a better understanding of bone biomechanics.
Collapse
Affiliation(s)
- Chunhui Ji
- School of Mechanical Engineering, Tianjin University, Tianjin 300072, PR China
| | - Liang Zhang
- School of Mechanical Engineering, Tianjin University, Tianjin 300072, PR China
| | - Yan Wang
- Tianjin Hospital, Tianjin University, Tianjin 300072, PR China
| | - Bin Lin
- School of Mechanical Engineering, Tianjin University, Tianjin 300072, PR China.
| | - Xinlei Bai
- School of Mechanical Engineering, Tianjin University, Tianjin 300072, PR China
| | - Shiyue Yun
- School of Mechanical Engineering, Tianjin University, Tianjin 300072, PR China
| | - Bingnan He
- School of Mechanical Engineering, Tianjin University, Tianjin 300072, PR China
| |
Collapse
|
2
|
Blouin S, Misof BM, Mähr M, Fratzl-Zelman N, Roschger P, Lueger S, Messmer P, Keplinger P, Rauch F, Glorieux FH, Berzlanovich A, Gruber GM, Brugger PC, Shane E, Recker RR, Zwerina J, Hartmann MA. Osteocyte lacunae in transiliac bone biopsy samples across life span. Acta Biomater 2023; 157:275-287. [PMID: 36549635 DOI: 10.1016/j.actbio.2022.11.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 11/23/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022]
Abstract
Osteocytes act as bone mechanosensors, regulators of osteoblast/osteoclast activity and mineral homeostasis, however, knowledge about their functional/morphological changes throughout life is limited. We used quantitative backscattered electron imaging (qBEI) to investigate osteocyte lacunae sections (OLS) as a 2D-surrogate characterizing the osteocytes. OLS characteristics, the density of mineralized osteocyte lacunae (i.e., micropetrotic osteocytes, md.OLS-Density in nb/mm2) and the average degree of mineralization (CaMean in weight% calcium) of cortex and spongiosa were analyzed in transiliac biopsy samples from healthy individuals under 30 (n=59) and over 30 years (n=50) (i.e., before and after the age of peak bone mass, respectively). We found several differences in OLS-characteristics: 1). Inter-individually between the age groups: OLS-Density and OLS-Porosity were reduced by about 20% in older individuals in spongiosa and in cortex versus younger probands (both, p < 0.001). 2). Intra-individually between bone compartments: OLS-Density was higher in the cortex, +18.4%, p < 0.001 for younger and +7.6%, p < 0.05 for older individuals. Strikingly, the most frequent OLS nearest-neighbor distance was about 30 µm in both age groups and at both bone sites revealing a preferential organization of osteocytes in clusters. OLS-Density was negatively correlated with CaMean in both spongiosa and cortex (both, p < 0.001). Few mineralized OLS were found in young individuals along with an increase of md.OLS-Density with age. In summary, this transiliac bone sample analysis of 200000 OLS from 109 healthy individuals throughout lifespan reveals several age-related differences in OLS characteristics. Moreover, our study provides reference data from healthy individuals for different ages to be used for diagnosis of bone abnormalities in diseases. STATEMENT OF SIGNIFICANCE: Osteocytes are bone cells embedded in lacunae within the mineralized bone matrix and have a key role in the bone metabolism and the mineral homeostasis. Not easily accessible, we used quantitative backscattered electron imaging to determine precisely number and shape descriptors of the osteocyte lacunae in 2D. We analyzed transiliac biopsy samples from 109 individuals with age distributed from 2 to 95 years. Compact cortical bone showed constantly higher lacunar density than cancellous bone but the lacunar density in both bone tissue decreased with age before the peak bone mass age at 30 years and stabilized or even increased after this age. This extensive study provides osteocyte lacunae reference data from healthy individuals usable for bone pathology diagnosis.
Collapse
Affiliation(s)
- Stéphane Blouin
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria.
| | - Barbara M Misof
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Matthias Mähr
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Nadja Fratzl-Zelman
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Paul Roschger
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Sonja Lueger
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Phaedra Messmer
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Petra Keplinger
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Frank Rauch
- Shriners Hospital for Children and McGill University, Montreal, ON QC, H4A 0A9, Canada
| | - Francis H Glorieux
- Shriners Hospital for Children and McGill University, Montreal, ON QC, H4A 0A9, Canada
| | - Andrea Berzlanovich
- Unit of Forensic Gerontology, Center of Forensic Medicine, Medical University of Vienna, Vienna, Austria
| | - Gerlinde M Gruber
- Department of Anatomy and Biomechanics, Karl Landsteiner University of Health Sciences, Krems, Austria
| | - Peter C Brugger
- Center for Anatomy and Cell Biology, Department of Anatomy, Medical University of Vienna, Vienna, Austria
| | - Elizabeth Shane
- Department of Medicine, Division of Endocrinology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Robert R Recker
- Osteoporosis Research Center, Creighton University, Omaha, Nebraska, USA
| | - Jochen Zwerina
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| | - Markus A Hartmann
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria & Vienna Bone and Growth Center, Vienna, Austria
| |
Collapse
|
3
|
Abstract
Bone is an outstanding, well-designed composite. It is constituted by a multi-level structure wherein its properties and behavior are dependent on its composition and structural organization at different length scales. The combination of unique mechanical properties with adaptive and self-healing abilities makes bone an innovative model for the future design of synthetic biomimetic composites with improved performance in bone repair and regeneration. However, the relation between structure and properties in bone is very complex. In this review article, we intend to describe the hierarchical organization of bone on progressively greater scales and present the basic concepts that are fundamental to understanding the arrangement-based mechanical properties at each length scale and their influence on bone’s overall structural behavior. The need for a better understanding of bone’s intricate composite structure is also highlighted.
Collapse
|