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Dejea H, Raina DB, Silva Barreto I, Sharma K, Liu Y, Ferreira Sanchez D, Johansson U, Isaksson H. Multi-scale characterization of the spatio-temporal interplay between elemental composition, mineral deposition and remodelling in bone fracture healing. Acta Biomater 2023:S1742-7061(23)00356-2. [PMID: 37369267 DOI: 10.1016/j.actbio.2023.06.031] [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: 03/31/2023] [Revised: 06/16/2023] [Accepted: 06/22/2023] [Indexed: 06/29/2023]
Abstract
Bone mineralization involves a complex orchestration of physico-chemical responses from the organism. Despite extensive studies, the detailed mechanisms of mineralization remain to be elucidated. This study aims to characterize bone mineralization using an in-vivo long bone fracture healing model in the rat. The spatio-temporal distribution of relevant elements was correlated to the deposition and maturation of hydroxyapatite and the presence of matrix remodeling compounds (MMP-13). Multi-scale measurements indicated that (i) zinc is required for both the initial mineral deposition and resorption processes during mature mineral remodeling; (ii) Zinc and MMP-13 show similar spatio-temporal trends during early mineralization; (iii) Iron acts locally and in coordination with zinc during mineralization, thus indicating novel evidence of the time-events and inter-play between the elements. These findings improve the understanding of bone mineralization by explaining the link between the different constituents of this process throughout the healing time. STATEMENT OF SIGNIFICANCE: Bone mineralization involves a complex orchestration of physico-chemical responses from the organism, the detailed mechanisms of which remain to be elucidated. This study presents a highly novel multi-scale multi-modal investigation of bone mineralization using bone fracture healing as a model system. We present original characterization of tissue mineralization, where we relate the spatio-temporal distribution of important trace elements to a key matrix remodeling compound (MMP-13), the initial deposition and maturation of hydroxyapatite and further remodeling processes. This is the first time that mineralization has been probed down to the nanometric level, and where key mineralization components have been investigated to achieve a comprehensive and mechanistic understanding of the underlying mineralization processes during bone healing.
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Affiliation(s)
- Hector Dejea
- Department of Biomedical Engineering, Lund University, 223 62 Lund, Sweden, MAX IV Laboratory, Lund University, 224 84 Lund, Sweden.
| | - Deepak Bushan Raina
- Orthopedics, Department of Clinical Sciences, Lund University, 223 62 Lund, Sweden.
| | | | - Kunal Sharma
- Department of Biomedical Engineering, Lund University, 223 62 Lund, Sweden.
| | - Yang Liu
- Orthopedics, Department of Clinical Sciences, Lund University, 223 62 Lund, Sweden.
| | | | - Ulf Johansson
- MAX IV Laboratory, Lund University, 224 84 Lund, Sweden.
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, 223 62 Lund, Sweden.
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2
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Finnilä MAJ, Das Gupta S, Turunen MJ, Hellberg I, Turkiewicz A, Lutz-Bueno V, Jonsson E, Holler M, Ali N, Hughes V, Isaksson H, Tjörnstrand J, Önnerfjord P, Guizar-Sicairos M, Saarakkala S, Englund M. Mineral Crystal Thickness in Calcified Cartilage and Subchondral Bone in Healthy and Osteoarthritic Human Knees. J Bone Miner Res 2022; 37:1700-1710. [PMID: 35770824 PMCID: PMC9540032 DOI: 10.1002/jbmr.4642] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 05/17/2022] [Accepted: 06/26/2022] [Indexed: 11/08/2022]
Abstract
Osteoarthritis (OA) is the most common joint disease, where articular cartilage degradation is often accompanied with sclerosis of the subchondral bone. However, the association between OA and tissue mineralization at the nanostructural level is currently not understood. In particular, it is technically challenging to study calcified cartilage, where relevant but poorly understood pathological processes such as tidemark multiplication and advancement occur. Here, we used state-of-the-art microfocus small-angle X-ray scattering with a 5-μm spatial resolution to determine the size and organization of the mineral crystals at the nanostructural level in human subchondral bone and calcified cartilage. Specimens with a wide spectrum of OA severities were acquired from both medial and lateral compartments of medial compartment knee OA patients (n = 15) and cadaver knees (n = 10). Opposing the common notion, we found that calcified cartilage has thicker and more mutually aligned mineral crystals than adjoining bone. In addition, we, for the first time, identified a well-defined layer of calcified cartilage associated with pathological tidemark multiplication, containing 0.32 nm thicker crystals compared to the rest of calcified cartilage. Finally, we found 0.2 nm thicker mineral crystals in both tissues of the lateral compartment in OA compared with healthy knees, indicating a loading-related disease process because the lateral compartment is typically less loaded in medial compartment knee OA. In summary, we report novel changes in mineral crystal thickness during OA. Our data suggest that unloading in the knee might be involved with the growth of mineral crystals, which is especially evident in the calcified cartilage. © 2022 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)
- Mikko A J Finnilä
- Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland.,Medical Research Center, University of Oulu, Oulu, Finland
| | - Shuvashis Das Gupta
- Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Mikael J Turunen
- Department of Applied Physics, Faculty of Science and Forestry, University of Eastern Finland, Kuopio, Finland
| | - Iida Hellberg
- Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Aleksandra Turkiewicz
- Clinical Epidemiology Unit, Orthopaedics, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
| | | | - Elin Jonsson
- Clinical Epidemiology Unit, Orthopaedics, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
| | - Mirko Holler
- Paul Scherrer Institut, Villigen PSI, Switzerland
| | - Neserin Ali
- Clinical Epidemiology Unit, Orthopaedics, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
| | - Velocity Hughes
- Clinical Epidemiology Unit, Orthopaedics, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, Lund, Sweden
| | - Jon Tjörnstrand
- Department of Orthopaedics, Skåne University Hospital, Lund, Sweden
| | - Patrik Önnerfjord
- Rheumatology and Molecular Skeletal Biology, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
| | | | - Simo Saarakkala
- Research Unit of Medical Imaging, Physics and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland.,Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland
| | - Martin Englund
- Clinical Epidemiology Unit, Orthopaedics, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Lund, Sweden
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3
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Silva Barreto I, Le Cann S, Ahmed S, Sotiriou V, Turunen MJ, Johansson U, Rodriguez‐Fernandez A, Grünewald TA, Liebi M, Nowlan NC, Isaksson H. Multiscale Characterization of Embryonic Long Bone Mineralization in Mice. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2002524. [PMID: 33173750 PMCID: PMC7610310 DOI: 10.1002/advs.202002524] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Indexed: 06/01/2023]
Abstract
Long bone mineralization occurs through endochondral ossification, where a cartilage template mineralizes into bone-like tissue with a hierarchical organization from the whole bone-scale down to sub-nano scale. Whereas this process has been extensively studied at the larger length scales, it remains unexplored at some of the smaller length scales. In this study, the changes in morphology, composition, and structure during embryonic mineralization of murine humeri are investigated using a range of high-resolution synchrotron-based imaging techniques at several length scales. With micro- and nanometer spatial resolution, the deposition of elements and the shaping of mineral platelets are followed. Rapid mineralization of the humeri occurs over approximately four days, where mineral to matrix ratio and calcium content in the most mineralized zone reach adult values shortly before birth. Interestingly, zinc is consistently found to be localized at the sites of ongoing new mineralization. The mineral platelets in the most recently mineralized regions are thicker, longer, narrower, and less aligned compared to those further into the mineralized region. In summary, this study demonstrates a specific spatial distribution of zinc, with highest concentration where new mineral is being deposited and that the newly formed mineral platelets undergo slight reshaping and reorganization during embryonic development.
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Affiliation(s)
| | - Sophie Le Cann
- Department of Biomedical EngineeringLund UniversityLund22100Sweden
| | - Saima Ahmed
- Department of BioengineeringImperial College LondonLondonSW72AZUK
| | - Vivien Sotiriou
- Department of BioengineeringImperial College LondonLondonSW72AZUK
| | - Mikael J. Turunen
- Department of Applied PhysicsUniversity of Eastern FinlandKuopio70211Finland
| | | | | | | | - Marianne Liebi
- Department of PhysicsChalmers University of TechnologyGothenburg41296Sweden
| | - Niamh C. Nowlan
- Department of BioengineeringImperial College LondonLondonSW72AZUK
| | - Hanna Isaksson
- Department of Biomedical EngineeringLund UniversityLund22100Sweden
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4
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Le Cann S, Törnquist E, Silva Barreto I, Fraulob M, Albini Lomami H, Verezhak M, Guizar-Sicairos M, Isaksson H, Haïat G. Spatio-temporal evolution of hydroxyapatite crystal thickness at the bone-implant interface. Acta Biomater 2020; 116:391-399. [PMID: 32937205 DOI: 10.1016/j.actbio.2020.09.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 08/24/2020] [Accepted: 09/09/2020] [Indexed: 02/02/2023]
Abstract
A better understanding of bone nanostructure around the bone-implant interface is essential to improve longevity of clinical implants and decrease failure risks. This study investigates the spatio-temporal evolution of mineral crystal thickness and plate orientation in newly formed bone around the surface of a metallic implant. Standardized coin-shaped titanium implants designed with a bone chamber were inserted into rabbit tibiae for 7 and 13 weeks. Scanning measurements with micro-focused small-angle X-ray scattering (SAXS) were carried out on newly formed bone close to the implant and in control mature cortical bone. Mineral crystals were thinner close to the implant (1.8 ± 0.45 nm at 7 weeks and 2.4 ± 0.57 nm at 13 weeks) than in the control mature bone tissue (2.5 ± 0.21 nm at 7 weeks and 2.8 ± 0.35 nm at 13 weeks), with increasing thickness over healing time (+30 % in 6 weeks). These results are explained by younger bone close to the implant, which matures during osseointegration. Thinner mineral crystals parallel to the implant surface within the first 100 µm indicate that the implant affects the ultrastructure of neighbouring bone , potentially due to heterogeneous interfacial stresses, and suggest a longer maturation process of bone tissue and difficulty in binding to the metal. The bone growth kinetics within the bone chamber was derived from the spatio-temporal evolution of bone tissue's nanostructure, coupled with microtomographic imaging. The findings indicate that understanding mineral crystal thickness or plate orientation can improve our knowledge of osseointegration.
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Affiliation(s)
- Sophie Le Cann
- MSME, CNRS UMR 8208, Univ Paris Est Creteil, Univ Gustave Eiffel, F-94010 Creteil, France.
| | - Elin Törnquist
- Department of Biomedical Engineering, Lund University, 221 00 Lund, Sweden
| | | | - Manon Fraulob
- MSME, CNRS UMR 8208, Univ Paris Est Creteil, Univ Gustave Eiffel, F-94010 Creteil, France
| | - Hugues Albini Lomami
- MSME, CNRS UMR 8208, Univ Paris Est Creteil, Univ Gustave Eiffel, F-94010 Creteil, France
| | - Mariana Verezhak
- Paul Scherrer Institut, Forschungsstrasse 111, Villigen 5232, Switzerland
| | | | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, 221 00 Lund, Sweden
| | - Guillaume Haïat
- MSME, CNRS UMR 8208, Univ Paris Est Creteil, Univ Gustave Eiffel, F-94010 Creteil, France
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5
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Kumar V, Asodiya FA, Singh VK, Gajera HP. Microscopic and spectroscopic characterization of an extraskeletal intranasal osteoma in a Gir cow. Microsc Res Tech 2020; 84:555-562. [PMID: 33037761 DOI: 10.1002/jemt.23613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 09/19/2020] [Accepted: 09/23/2020] [Indexed: 01/12/2023]
Abstract
This is probably the first report characterizing an extraskeletal intranasal osteoma in a Gir cow through scanning electron microscopy and various spectroscopic techniques. Nasal obstruction in a 10-year-old Gir cow is investigated in this study. Skull radiograph demonstrated 174.12 mm × 81.97 mm sized well-circumscribed radiodense mass within the left nasal passage. The intranasal mass was excised completely through a rhinotomy incision. Grossly, intranasal mass was nonhyperemic, rock-hard, and calcified, 174.12 mm × 81.97 mm in size, and 650 g of weight. Excised intranasal mass was investigated through histopathologic, scanning electron microscopic (SEM), energy-dispersive X-ray (EDX) spectroscopic, X-ray fluorescence (XRF) spectroscopic, microwave plasma-atomic energy spectroscopic (MPAES), and Fourier-transform infrared (FTIR) spectroscopic techniques. A native bone of age-matched Gir cow, collected from a cadaver, was taken as a control. Microscopically, structures similar to cortical bone randomly coexisted with trabecular bone were observed. The EDX analysis of the intranasal mass indicated mean Ca/P weight ratio of 1.88, close to Ca/P weight ratio of the control. The XRF analysis revealed the presence of Ca, P, Sr, S, Zn, Cu, Fe, and Ni in the intranasal mass. Additionally, Mn was noted by MPAES analysis. Hence, the XRF and MPAES analyses confirmed a similar elemental composition of the intranasal mass and control. FTIR spectroscopic study confirmed the presence of inorganic ν1, ν3 PO4 3- , OH- in addition to organic collagen amide A, amide B, amide I, amide II, and amide III chemical functional groups in the intranasal mass. These findings of the intranasal mass were consistent with an osteoma having similar elemental and molecular compositions with the native bone.
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Affiliation(s)
- Vineet Kumar
- Department of Veterinary Surgery and Radiology, College of Veterinary and Animal Sciences, Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, India
| | - Foram A Asodiya
- Department of Veterinary Surgery and Radiology, College of Veterinary Science and Animal Husbandry, Junagadh Agricultural University, Junagadh, India
| | - Vivek K Singh
- Department of Veterinary Physiology and Biochemistry, College of Veterinary Science and Animal Husbandry, Junagadh Agricultural University, Junagadh, India
| | - Harsukh P Gajera
- Department of Biotechnology, Junagadh Agricultural University, Junagadh, India
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6
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Cassini C, Wittmeier A, Brehm G, Denz M, Burghammer M, Köster S. Large field-of-view scanning small-angle X-ray scattering of mammalian cells. JOURNAL OF SYNCHROTRON RADIATION 2020; 27:1059-1068. [PMID: 33566016 PMCID: PMC7336178 DOI: 10.1107/s1600577520006864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Accepted: 05/21/2020] [Indexed: 06/12/2023]
Abstract
X-ray imaging is a complementary method to electron and fluorescence microscopy for studying biological cells. In particular, scanning small-angle X-ray scattering provides overview images of whole cells in real space as well as local, high-resolution reciprocal space information, rendering it suitable to investigate subcellular nanostructures in unsliced cells. One persisting challenge in cell studies is achieving high throughput in reasonable times. To this end, a fast scanning mode is used to image hundreds of cells in a single scan. A way of dealing with the vast amount of data thus collected is suggested, including a segmentation procedure and three complementary kinds of analysis, i.e. characterization of the cell population as a whole, of single cells and of different parts of the same cell. The results show that short exposure times, which enable faster scans and reduce radiation damage, still yield information in agreement with longer exposure times.
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Affiliation(s)
- Chiara Cassini
- Institute for X-ray Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
- Cluster of Excellence ‘Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells (MBExC)’, University of Göttingen, Germany
| | - Andrew Wittmeier
- Institute for X-ray Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Gerrit Brehm
- Institute for X-ray Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
- Cluster of Excellence ‘Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells (MBExC)’, University of Göttingen, Germany
| | - Manuela Denz
- Institute for X-ray Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Manfred Burghammer
- European Synchrotron Radiation Facility, 71 Avenue des Martyrs, 38043 Grenoble, France
| | - Sarah Köster
- Institute for X-ray Physics, University of Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
- Cluster of Excellence ‘Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells (MBExC)’, University of Göttingen, Germany
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7
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Törnquist E, Isaksson H, Turunen MJ. Mineralization of cortical bone during maturation and growth in rabbits. J Bone Miner Metab 2020; 38:289-298. [PMID: 31807903 DOI: 10.1007/s00774-019-01068-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 11/06/2019] [Indexed: 02/02/2023]
Abstract
INTRODUCTION The composite nature of bone as a material governs its structure and mechanical behavior. How the collagenous matrix mineralizes, in terms of both mineral deposition and structure of the mineral crystals, is highly interesting when trying to elucidate the complex structural changes that occur during bone growth and maturation. We have previously looked at mineral deposition and structural evolution of the collagenous matrix, linking both to changes in mechanics. The purpose of this study was to provide specific information on changes in crystal size and organization as a function of growth and maturation. MATERIALS AND METHODS Using micro-computed tomography (µCT) and micro-focused scanning small-angle X-ray scattering (SAXS) we investigated cortical bone in two orthogonal directions relative to the long axis of the humeri of New Zealand White rabbits spanning from new-born to 6-months of age. We also investigated the changes with tissue age by looking at radial profiles of osteonal structures in the 6-months old rabbits. The findings were compared to our previous compositional, structural and mechanical data on the same sample cohort. RESULTS µCT showed a continuous mineral deposition up until 3-months of age, whilst the SAXS data showed an increase in both crystal thickness and degree of orientation up until 6-months of age. The osteonal profiles showed no statistically significant changes in crystal thickness. CONCLUSIONS Comparison to previously collected mechanical data suggests that changes are not only explained by amount of mineral in the tissue but also by the crystal dimensions.
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Affiliation(s)
- Elin Törnquist
- Department of Biomedical Engineering, Lund University, PO Box 118, 221 00, Lund, Sweden.
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, PO Box 118, 221 00, Lund, Sweden
| | - Mikael J Turunen
- Department of Biomedical Engineering, Lund University, PO Box 118, 221 00, Lund, Sweden
- Department of Applied Physics, University of Eastern Finland, 702 11, Kuopio, Finland
- SIBlabs, University of Eastern Finland, 702 11, Kuopio, Finland
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8
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Gustafsson A, Mathavan N, Turunen MJ, Engqvist J, Khayyeri H, Hall SA, Isaksson H. Linking multiscale deformation to microstructure in cortical bone using in situ loading, digital image correlation and synchrotron X-ray scattering. Acta Biomater 2018; 69:323-331. [PMID: 29410089 DOI: 10.1016/j.actbio.2018.01.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/20/2017] [Accepted: 01/25/2018] [Indexed: 11/27/2022]
Abstract
The incidence of fragility fractures is expected to increase in the near future due to an aging population. Therefore, improved tools for fracture prediction are required to treat and prevent these injuries efficiently. For such tools to succeed, a better understanding of the deformation mechanisms in bone over different length scales is needed. In this study, an experimental setup including mechanical tensile testing in combination with digital image correlation (DIC) and small/wide angle X-ray scattering (SAXS/WAXS) was used to study deformation at multiple length scales in bovine cortical bone. Furthermore, micro-CT imaging provided detailed information about tissue microstructure. The combination of these techniques enabled measurements of local deformations at the tissue- and nanoscales. The orientation of the microstructure relative to the tensile loading was found to influence the strain magnitude on all length scales. Strains in the collagen fibers were 2-3 times as high as the strains found in the mineral crystals for samples with microstructure oriented parallel to the loading. The local tissue strain at fracture was found to be around 0.5%, independent of tissue orientation. However, the maximum force and the irregularity of the crack path were higher when the load was applied parallel to the tissue orientation. This study clearly shows the potential of combining these different experimental techniques concurrently with mechanical testing to gain a better understanding of bone damage and fracture over multiple length scales in cortical bone. STATEMENT OF SIGNIFICANCE To understand the pathophysiology of bone, it is important to improve our knowledge about the deformation and fracture mechanisms in bone. In this study, we combine several recently available experimental techniques with mechanical loading to investigate the deformation mechanisms in compact bone tissue on several length scales simultaneously. The experimental setup included mechanical tensile testing in combination with digital image correlation, microCT imaging, and small/wide angle X-ray scattering. The combination of techniques enabled measurements of local deformations at the tissue- and nanoscales. The study clearly shows the potential of combining different experimental techniques concurrently with mechanical testing to gain a better understanding of structure-property-function relationships in bone tissue.
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Affiliation(s)
- Anna Gustafsson
- Department of Biomedical Engineering, Lund University, Box 118, SE-221 00 Lund, Sweden.
| | - Neashan Mathavan
- Department of Biomedical Engineering, Lund University, Box 118, SE-221 00 Lund, Sweden.
| | - Mikael J Turunen
- Department of Biomedical Engineering, Lund University, Box 118, SE-221 00 Lund, Sweden; Department of Applied Physics, University of Eastern Finland, POB 1627, FI-702 11 Kuopio, Finland.
| | - Jonas Engqvist
- Division of Solid Mechanics, Lund University, Box 118, SE-221 00 Lund, Sweden.
| | - Hanifeh Khayyeri
- Department of Biomedical Engineering, Lund University, Box 118, SE-221 00 Lund, Sweden.
| | - Stephen A Hall
- Division of Solid Mechanics, Lund University, Box 118, SE-221 00 Lund, Sweden.
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, Box 118, SE-221 00 Lund, Sweden.
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9
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Mathavan N, Turunen MJ, Guizar-Sicairos M, Bech M, Schaff F, Tägil M, Isaksson H. The compositional and nano-structural basis of fracture healing in healthy and osteoporotic bone. Sci Rep 2018; 8:1591. [PMID: 29371668 PMCID: PMC5785543 DOI: 10.1038/s41598-018-19296-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 12/28/2017] [Indexed: 01/08/2023] Open
Abstract
Osteoporosis, a prevalent metabolic bone disorder, predisposes individuals to increased susceptibility to fractures. It is also, somewhat controversially, thought to delay or impair the regenerative response. Using high-resolution Fourier-transform infrared spectroscopy and small/wide-angle X-ray scattering we sought to answer the following questions: Does the molecular composition and the nano-structure in the newly regenerated bone differ between healthy and osteoporotic environments? And how do pharmacological treatments, such as bone morphogenetic protein 7 (BMP-7) alone or synergistically combined with zoledronate (ZA), alter callus composition and nano-structure in such environments? Cumulatively, on the basis of compositional and nano-structural characterizations of newly formed bone in an open-osteotomy rat model, the healing response in untreated healthy and ovariectomy-induced osteoporotic environments was fundamentally the same. However, the BMP-7 induced osteogenic response resulted in greater heterogeneity in the nano-structural crystal dimensions and this effect was more pronounced with osteoporosis. ZA mitigated the effects of the upregulated catabolism induced by both BMP-7 and an osteoporotic bone environment. The findings contribute to our understanding of how the repair processes in healthy and osteoporotic bone differ in both untreated and treated contexts and the data presented represents the most comprehensive study of fracture healing at the nanoscale undertaken to date.
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Affiliation(s)
- Neashan Mathavan
- Department of Biomedical Engineering, Lund University, Lund, Sweden.
| | - Mikael J Turunen
- Department of Biomedical Engineering, Lund University, Lund, Sweden.,Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
| | | | - Martin Bech
- Department of Medical Radiation Physics, Lund University, Lund, Sweden
| | - Florian Schaff
- Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, Garching, Germany
| | - Magnus Tägil
- Department of Orthopaedics, Clinical Sciences, Lund University and Skåne University Hospital, Lund, Sweden
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, Lund, Sweden.,Department of Orthopaedics, Clinical Sciences, Lund University and Skåne University Hospital, Lund, Sweden
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10
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Achilles tendon compositional and structural properties are altered after unloading by botox. Sci Rep 2017; 7:13067. [PMID: 29026107 PMCID: PMC5638919 DOI: 10.1038/s41598-017-13107-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 09/18/2017] [Indexed: 02/07/2023] Open
Abstract
Tendon function and homeostasis rely on external loading. This study investigates the biological mechanisms behind tendon biomechanical function and how the mechanical performance is affected by reduced daily loading. The Achilles tendons of 16 weeks old female Sprague Dawley rats (n = 40) were unloaded for 5 weeks by inducing muscle paralysis with botulinum toxin injections in the right gastrocnemius and soleus muscles. The contralateral side was used as control. After harvest, the tendons underwent biomechanical testing to assess viscoelasticity (n = 30 rats) and small angle X-ray scattering to determine the structural properties of the collagen fibrils (n = 10 rats). Fourier transform infrared spectroscopy and histological staining (n = 10 rats) were performed to investigate the collagen and proteoglycan content. The results show that the stiffness increased in unloaded tendons, together with an increased collagen content. Creep and axial alignment of the collagen fibers were reduced. Stress-relaxation increased whereas hysteresis was reduced in response to unloading with botox treatment. Our findings indicate that altered matrix deposition relies on mechanical loading to reorganize the newly formed tissue, without which the viscoelastic behavior is impaired. The results demonstrate that reduced daily loading deprives tendons of their viscoelastic properties, which could increase the risk of injury.
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11
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Bergström I, Kerns JG, Törnqvist AE, Perdikouri C, Mathavan N, Koskela A, Henriksson HB, Tuukkanen J, Andersson G, Isaksson H, Goodship AE, Windahl SH. Compressive loading of the murine tibia reveals site-specific micro-scale differences in adaptation and maturation rates of bone. Osteoporos Int 2017; 28:1121-1131. [PMID: 27921145 PMCID: PMC5306148 DOI: 10.1007/s00198-016-3846-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 11/16/2016] [Indexed: 01/16/2023]
Abstract
Loading increases bone mass and strength in a site-specific manner; however, possible effects of loading on bone matrix composition have not been evaluated. Site-specific structural and material properties of mouse bone were analyzed on the macro- and micro/molecular scale in the presence and absence of axial loading. The response of bone to load is heterogeneous, adapting at molecular, micro-, and macro-levels. INTRODUCTION Osteoporosis is a degenerative disease resulting in reduced bone mineral density, structure, and strength. The overall aim was to explore the hypothesis that changes in loading environment result in site-specific adaptations at molecular/micro- and macro-scale in mouse bone. METHODS Right tibiae of adult mice were subjected to well-defined cyclic axial loading for 2 weeks; left tibiae were used as physiologically loaded controls. The bones were analyzed with μCT (structure), reference point indentation (material properties), Raman spectroscopy (chemical), and small-angle X-ray scattering (mineral crystallization and structure). RESULTS The cranial and caudal sites of tibiae are structurally and biochemically different within control bones. In response to loading, cranial and caudal sites increase in cortical thickness with reduced mineralization (-14 and -3%, p < 0.01, respectively) and crystallinity (-1.4 and -0.3%, p < 0.05, respectively). Along the length of the loaded bones, collagen content becomes more heterogeneous on the caudal site and the mineral/collagen increases distally at both sites. CONCLUSION Bone structure and composition are heterogeneous, finely tuned, adaptive, and site-specifically responsive at the micro-scale to maintain optimal function. Manipulation of this heterogeneity may affect bone strength, relative to specific applied loads.
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Affiliation(s)
- I Bergström
- Department of Endocrinology, Metabolism and Diabetes, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden
| | - J G Kerns
- UCL Institute of Orthopedics and Musculoskeletal Science, Royal National Orthopedic Hospital, London, UK
- Lancaster Medical School, Faculty of Health and Medicine, Lancaster University, Lancaster, LA1 4YG, UK
| | - A E Törnqvist
- Rheumatology and Bone Diseases Unit, Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - C Perdikouri
- Department of Biomedical Engineering and Department of Orthopedics, Lund University, Lund, Sweden
| | - N Mathavan
- Department of Biomedical Engineering and Department of Orthopedics, Lund University, Lund, Sweden
| | - A Koskela
- Institute of Cancer and Translational Medicine, Department of Anatomy and Cell Biology, MRC Oulu, University of Oulu, Oulu, Finland
| | - H B Henriksson
- Department of Orthopedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Orthopedics, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - J Tuukkanen
- Institute of Cancer and Translational Medicine, Department of Anatomy and Cell Biology, MRC Oulu, University of Oulu, Oulu, Finland
| | - G Andersson
- Department of Laboratory Medicine, Division of Pathology, Karolinska University Hospital, Karolinska Institutet, Huddinge, Stockholm, Sweden
| | - H Isaksson
- Department of Biomedical Engineering and Department of Orthopedics, Lund University, Lund, Sweden
| | - A E Goodship
- UCL Institute of Orthopedics and Musculoskeletal Science, Royal National Orthopedic Hospital, London, UK
- Centre for Comparative and Clinical Anatomy, School of Veterinary Science, University of Bristol, Bristol, UK
| | - S H Windahl
- Centre for Bone and Arthritis Research, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
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12
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Turunen MJ, Kaspersen JD, Olsson U, Guizar-Sicairos M, Bech M, Schaff F, Tägil M, Jurvelin JS, Isaksson H. Bone mineral crystal size and organization vary across mature rat bone cortex. J Struct Biol 2016; 195:337-344. [DOI: 10.1016/j.jsb.2016.07.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 07/07/2016] [Accepted: 07/09/2016] [Indexed: 01/13/2023]
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13
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Kogan NM, Melamed E, Wasserman E, Raphael B, Breuer A, Stok KS, Sondergaard R, Escudero AVV, Baraghithy S, Attar-Namdar M, Friedlander-Barenboim S, Mathavan N, Isaksson H, Mechoulam R, Müller R, Bajayo A, Gabet Y, Bab I. Cannabidiol, a Major Non-Psychotropic Cannabis Constituent Enhances Fracture Healing and Stimulates Lysyl Hydroxylase Activity in Osteoblasts. J Bone Miner Res 2015; 30:1905-13. [PMID: 25801536 DOI: 10.1002/jbmr.2513] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 02/15/2015] [Accepted: 03/18/2015] [Indexed: 12/16/2022]
Abstract
Cannabinoid ligands regulate bone mass, but skeletal effects of cannabis (marijuana and hashish) have not been reported. Bone fractures are highly prevalent, involving prolonged immobilization and discomfort. Here we report that the major non-psychoactive cannabis constituent, cannabidiol (CBD), enhances the biomechanical properties of healing rat mid-femoral fractures. The maximal load and work-to-failure, but not the stiffness, of femurs from rats given a mixture of CBD and Δ(9) -tetrahydrocannabinol (THC) for 8 weeks were markedly increased by CBD. This effect is not shared by THC (the psychoactive component of cannabis), but THC potentiates the CBD stimulated work-to-failure at 6 weeks postfracture followed by attenuation of the CBD effect at 8 weeks. Using micro-computed tomography (μCT), the fracture callus size was transiently reduced by either CBD or THC 4 weeks after fracture but reached control level after 6 and 8 weeks. The callus material density was unaffected by CBD and/or THC. By contrast, CBD stimulated mRNA expression of Plod1 in primary osteoblast cultures, encoding an enzyme that catalyzes lysine hydroxylation, which is in turn involved in collagen crosslinking and stabilization. Using Fourier transform infrared (FTIR) spectroscopy we confirmed the increase in collagen crosslink ratio by CBD, which is likely to contribute to the improved biomechanical properties of the fracture callus. Taken together, these data show that CBD leads to improvement in fracture healing and demonstrate the critical mechanical role of collagen crosslinking enzymes.
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Affiliation(s)
- Natalya M Kogan
- Bone Laboratory, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eitan Melamed
- Bone Laboratory, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Elad Wasserman
- Bone Laboratory, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Bitya Raphael
- Bone Laboratory, Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Aviva Breuer
- Institute for Drug Research, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Kathryn S Stok
- Institute for Biomechanics, ETH Zürich, Zürich, Switzerland
| | | | | | - Saja Baraghithy
- Bone Laboratory, Hebrew University of Jerusalem, Jerusalem, Israel
| | | | | | - Neashan Mathavan
- Department of Biomedical Engineering, Lund University, Lund, Sweden.,Department of Orthopedics, Lund University, Lund, Sweden
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, Lund, Sweden.,Department of Orthopedics, Lund University, Lund, Sweden
| | - Raphael Mechoulam
- Institute for Drug Research, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Ralph Müller
- Institute for Biomechanics, ETH Zürich, Zürich, Switzerland
| | - Alon Bajayo
- Bone Laboratory, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yankel Gabet
- Department of Anatomy and Anthropology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Itai Bab
- Bone Laboratory, Hebrew University of Jerusalem, Jerusalem, Israel
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14
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Mathavan N, Turunen MJ, Tägil M, Isaksson H. Characterising bone material composition and structure in the ovariectomized (OVX) rat model of osteoporosis. Calcif Tissue Int 2015; 97:134-44. [PMID: 25894067 DOI: 10.1007/s00223-015-9991-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 03/25/2015] [Indexed: 01/14/2023]
Abstract
The ovariectomized (OVX) rat model is well established in investigations of osteoporosis and osteoporotic therapies. Advent of techniques such as Fourier-transform infrared (FTIR) spectroscopy and small angle X-ray scattering (SAXS) facilitate characterization of bone composition and mineral structure, respectively, which are key determinants of bone strength. Limited publications exist on the implementation of these techniques in the OVX rat model. At 12 weeks of age, female Sprague-Dawley rats were either sham-operated (n = 6) or ovariectomized (n = 6) and sacrificed 18 weeks later. L2 lumbar vertebrae and proximal tibiae were assessed by µCT, FTIR and SAXS. Presence of extensive trabecular deterioration in the µCT data confirmed the onset of osteoporosis. FTIR compositional parameters were determined including measures of degree of mineralization, crystallinity, collagen maturity and acid phosphate content. Mineral crystal thickness was determined from the SAXS data using two approaches available in literature. Compositionally, a decline in the heterogeneity of acid phosphate content was observed while measures of crystallinity and collagen maturity remained unaltered. Using an iterative curve fitting method, OVX-induced increases in the mineral crystal thickness of 3.8 and 7.8 % (p < 0.05) were noted in the trabecular of the vertebra and tibia, respectively. In conclusion, implementation of FTIR and SAXS techniques in the OVX rat model, identified no significant compositional changes while substantiating thickening of the mineral crystals as a general structural feature of OVX-induced osteoporosis in rats.
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Affiliation(s)
- Neashan Mathavan
- Department of Biomedical Engineering, Lund University, PO Box 118, 221 00, Lund, Sweden,
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15
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Bosemark P, Perdikouri C, Pelkonen M, Isaksson H, Tägil M. The masquelet induced membrane technique with BMP and a synthetic scaffold can heal a rat femoral critical size defect. J Orthop Res 2015; 33:488-95. [PMID: 25639666 DOI: 10.1002/jor.22815] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 12/19/2014] [Indexed: 02/04/2023]
Abstract
Long bone defects can be managed by the induced membrane technique together with autologous bone graft. However, graft harvest is associated with donor site morbidity. This study investigates if a tricalcium phosphate hydroxyapatite scaffold can be used alone or in combination with bone active drugs to improve healing. Sprague Dawley rats (n = 40) were randomized into four groups. (A) scaffold, (B) BMP-7, (C) BMP-7 + scaffold, and (D) BMP-7 + scaffold + systemic bisphosphonate at 2 weeks. Locked femoral nailing was followed by 6 mm segment removal and implantation of an epoxy spacer. At 4 weeks, the spacers were removed and the defects grafted. Eleven weeks later, the bones were explanted for evaluation with radiography, manual assessment, micro-CT, histology, and Fourier Transform Infrared spectroscopy (FTIR). Isolated scaffolds (A) did not heal any defects, whereas the other treatments led to healing in 7/10 (B), 10/10 (C), and 9/10 (D) rats. Group D had greater volume of highly mineralized bone (p < 0.01) and higher bone volume fraction (p < 0.01) compared to all other groups. A synthetic scaffold + BMP-7 combined with a bisphosphonate improved the callus properties in a rat femoral critical size defect, compared to both BMP-7 and scaffold alone or the two combined.
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Affiliation(s)
- Per Bosemark
- Department of Orthopaedics, Clinical Sciences, Lund University, Lund, Sweden
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16
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Kamal B, Russell D, Payne A, Constante D, Tanner KE, Isaksson H, Mathavan N, Cobb SR. Biomechanical properties of bone in a mouse model of Rett syndrome. Bone 2015; 71:106-14. [PMID: 25445449 PMCID: PMC4289916 DOI: 10.1016/j.bone.2014.10.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 10/09/2014] [Accepted: 10/15/2014] [Indexed: 12/22/2022]
Abstract
Rett syndrome (RTT) is an X-linked genetic disorder and a major cause of intellectual disability in girls. Mutations in the methyl-CpG binding protein 2 (MECP2) gene are the primary cause of the disorder. Despite the dominant neurological phenotypes, MECP2 is expressed ubiquitously throughout the body and a number of peripheral phenotypes such as scoliosis, reduced bone mineral density and skeletal fractures are also common and important clinical features of the disorder. In order to explore whether MeCP2 protein deficiency results in altered structural and functional properties of bone and to test the potential reversibility of any defects, we have conducted a series of histological, imaging and biomechanical tests of bone in a functional knockout mouse model of RTT. Both hemizygous Mecp2(stop/y) male mice in which Mecp2 is silenced in all cells and female Mecp2(stop/+) mice in which Mecp2 is silenced in ~50% of cells as a consequence of random X-chromosome inactivation, revealed significant reductions in cortical bone stiffness, microhardness and tensile modulus. Microstructural analysis also revealed alterations in both cortical and cancellous femoral bone between wild-type and MeCP2-deficient mice. Furthermore, unsilencing of Mecp2 in adult mice cre-mediated stop cassette deletion resulted in a restoration of biomechanical properties (stiffness, microhardness) towards wild-type levels. These results show that MeCP2-deficiency results in overt, but potentially reversible, alterations in the biomechanical integrity of bone and highlights the importance of targeting skeletal phenotypes in considering the development of pharmacological and gene-based therapies.
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Affiliation(s)
- Bushra Kamal
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QQ, UK; Laboratory of Human Anatomy, School of Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK; Department of Anatomy, Khyber Medical University, Khyber Pakhtunkhwa, Pakistan
| | - David Russell
- Laboratory of Human Anatomy, School of Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Anthony Payne
- Laboratory of Human Anatomy, School of Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Diogo Constante
- School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK; Faculadade de Engenharia da Universidade do Porto, Porto, Portugal
| | - K Elizabeth Tanner
- School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK; Department of Orthopaedics, Clinical Sciences, Lund University, Lund, S-22185, Sweden
| | - Hanna Isaksson
- Department of Biomedical Engineering, Lund University, Lund, Sweden
| | - Neashan Mathavan
- Department of Biomedical Engineering, Lund University, Lund, Sweden
| | - Stuart R Cobb
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QQ, UK.
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17
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Gollwitzer H, Yang X, Spevak L, Lukashova L, Nocon A, Fields K, Pleshko N, Courtland HW, Bostrom MP, Boskey AL. Fourier Transform Infrared Spectroscopic Imaging of Fracture Healing in the Normal Mouse. JOURNAL OF SPECTROSCOPY (HINDAWI) 2015; 2015:659473. [PMID: 26034749 PMCID: PMC4448139 DOI: 10.1155/2015/659473] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Fourier transform infrared spectroscopic imaging (FTIRI) was used to study bone healing with spatial analysis of various callus tissues in wild type mice. Femoral fractures were produced in 28 male C57BL mice by osteotomy. Animals were sacrificed at 1, 2, 4, and 8 weeks to obtain callus tissue at well-defined healing stages. Following microcomputerized tomography, bone samples were cut in consecutive sections for FTIRI and histology, allowing for spatial correlation of both imaging methods in different callus areas (early calcified cartilage, woven bone, areas of intramembranous and endochondral bone formation). Based on FTIRI, mineral/matrix ratio increased significantly during the first 4 weeks of fracture healing in all callus areas and correlated with bone mineral density measured by micro-CT. Carbonate/phosphate ratio was elevated in newly formed calcified tissue and at week 2 attained values comparable to cortical bone. Collagen maturity and mineral crystallinity increased during weeks 1-8 in most tissues while acid phosphate substitution decreased. Temporal and callus area dependent changes were detected throughout the healing period. These data assert the usefulness of FTIRI for evaluation of fracture healing in the mouse and its potential to evaluate pathologic fracture healing and the effects of therapeutic interventions.
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Affiliation(s)
- Hans Gollwitzer
- Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA
- Klinik für Orthopädie und Sportorthopädie, Technische Universität München, Ismaningerstrasse 22, 81675 Munich, Germany
| | - Xu Yang
- Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA
| | - Lyudmila Spevak
- Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA
| | - Lyudmila Lukashova
- Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA
| | - Allina Nocon
- Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA
| | - Kara Fields
- Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA
| | - Nancy Pleshko
- Temple University College of Engineering, 1947 N. 12th Street, Philadelphia, PA 19122, USA
| | | | - Mathias P. Bostrom
- Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA
| | - Adele L. Boskey
- Hospital for Special Surgery, 535 E. 70th Street, New York, NY 10021, USA
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