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von Kroge S, Stürznickel J, Bechler U, Stockhausen KE, Eissele J, Hubert J, Amling M, Beil FT, Busse B, Rolvien T. Impaired bone quality in the superolateral femoral neck occurs independent of hip geometry and bone mineral density. Acta Biomater 2022; 141:233-243. [PMID: 34999261 DOI: 10.1016/j.actbio.2022.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 12/30/2021] [Accepted: 01/03/2022] [Indexed: 11/01/2022]
Abstract
Skeletal adaptation is substantially influenced by mechanical loads. Osteocytes and their lacuno-canalicular network have been identified as a key player in load sensation and bone quality regulation. In the femoral neck, one of the most common fracture sites, a complex loading pattern with lower habitual loading in the superolateral neck and higher compressive stresses in the inferomedial neck is present. Variations in the femoral neck-shaft angle (NSA), i.e., coxa vara or coxa valga, provide the opportunity to examine the influence of loading patterns on bone quality. We obtained femoral neck specimens of 28 osteoarthritic human subjects with coxa vara, coxa norma and coxa valga during total hip arthroplasty. Bone mineral density (BMD) was assessed preoperatively by dual energy X-ray absorptiometry (DXA). Cortical and trabecular microstructure and three-dimensional osteocyte lacunar characteristics were assessed in the superolateral and inferomedial neck using ex vivo high resolution micro-computed tomography. Additionally, BMD distribution and osteocyte lacunar characteristics were analyzed by quantitative backscattered electron imaging (qBEI). All groups presented thicker inferomedial than superolateral cortices. Furthermore, the superolateral site exhibited a lower osteocyte lacunar density along with lower lacunar sphericity than the inferomedial site, independent of NSA. Importantly, BMD and corresponding T-scores correlated with microstructural parameters at the inferomedial but not superolateral neck. In conclusion, we provide micromorphological evidence for fracture vulnerability of the superolateral neck, which is independent of NSA and BMD. The presented bone qualitative data provide an explanation why DXA may be insufficient to predict a substantial proportion of femoral neck fractures. STATEMENT OF SIGNIFICANCE: The femoral neck, one of the most common fracture sites, is subject to a complex loading pattern. Site-specific differences (i.e., superolateral vs. inferomedial) in bone quality influence fracture risk, but it is unclear how this relates to hip geometry and bone mineral density (BMD) measurements in vivo. Here, we examine femoral neck specimens using a variety of high-resolution imaging techniques and demonstrate impaired bone quality in the superolateral compared to the inferomedial neck. Specifically, we found impaired cortical and trabecular microarchitecture, mineralization, and osteocyte properties, regardless of neck-shaft angle. Since BMD correlated with bone quality of the inferomedial but not the superolateral neck, our results illustrate why bone densitometry may not predict a substantial proportion of femoral neck fractures.
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Vollersen N, Zhao W, Rolvien T, Lange F, Schmidt FN, Sonntag S, Shmerling D, von Kroge S, Stockhausen KE, Sharaf A, Schweizer M, Karsak M, Busse B, Bockamp E, Semler O, Amling M, Oheim R, Schinke T, Yorgan TA. The WNT1 G177C mutation specifically affects skeletal integrity in a mouse model of osteogenesis imperfecta type XV. Bone Res 2021; 9:48. [PMID: 34759273 PMCID: PMC8580994 DOI: 10.1038/s41413-021-00170-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 05/28/2021] [Accepted: 06/27/2021] [Indexed: 12/27/2022] Open
Abstract
The recent identification of homozygous WNT1 mutations in individuals with osteogenesis imperfecta type XV (OI-XV) has suggested that WNT1 is a key ligand promoting the differentiation and function of bone-forming osteoblasts. Although such an influence was supported by subsequent studies, a mouse model of OI-XV remained to be established. Therefore, we introduced a previously identified disease-causing mutation (G177C) into the murine Wnt1 gene. Homozygous Wnt1G177C/G177C mice were viable and did not display defects in brain development, but the majority of 24-week-old Wnt1G177C/G177C mice had skeletal fractures. This increased bone fragility was not fully explained by reduced bone mass but also by impaired bone matrix quality. Importantly, the homozygous presence of the G177C mutation did not interfere with the osteoanabolic influence of either parathyroid hormone injection or activating mutation of LRP5, the latter mimicking the effect of sclerostin neutralization. Finally, transcriptomic analyses revealed that short-term administration of WNT1 to osteogenic cells induced not only the expression of canonical WNT signaling targets but also the expression of genes encoding extracellular matrix modifiers. Taken together, our data demonstrate that regulating bone matrix quality is a primary function of WNT1. They further suggest that individuals with WNT1 mutations should profit from existing osteoanabolic therapies.
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Affiliation(s)
- Nele Vollersen
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Wenbo Zhao
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Tim Rolvien
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Fabiola Lange
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Felix Nikolai Schmidt
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Stephan Sonntag
- PolyGene AG, 8153, Rümlang, Switzerland.,ETH Phenomics Center (EPIC), ETH Zürich, 8092, Zürich, Switzerland
| | | | - Simon von Kroge
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Kilian Elia Stockhausen
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Ahmed Sharaf
- Neuronal and Cellular Signal Transduction, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Michaela Schweizer
- Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center, Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Meliha Karsak
- Neuronal and Cellular Signal Transduction, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Ernesto Bockamp
- Institute for Translational Immunology and Research Center for Immunotherapy, University Medical Center, Johannes Gutenberg University, D 55131, Mainz, Germany
| | - Oliver Semler
- Faculty of Medicine and University Hospital Cologne, Department of Pediatrics, University of Cologne, 50937, Cologne, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Ralf Oheim
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany.
| | - Timur Alexander Yorgan
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany.
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Stockhausen KE, Riedel C, Belinski AV, Rothe D, Gehrke T, Klebig F, Gebauer M, Amling M, Citak M, Busse B. Variability in stem taper surface topography affects the degree of corrosion and fretting in total hip arthroplasty. Sci Rep 2021; 11:9348. [PMID: 33931680 PMCID: PMC8087796 DOI: 10.1038/s41598-021-88234-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 03/19/2021] [Indexed: 12/29/2022] Open
Abstract
Degradation at the modular head-neck interface in total hip arthroplasty (THA) is predominately expressed in the form of corrosion and fretting, potentially causing peri-prosthetic failure by adverse reactions to metal debris. This retrieval study aimed to quantify variations in stem taper surface topographies and to assess the influence on the formation of corrosion and/or fretting in titanium alloy stem tapers combined with metal and ceramic heads. Four hip stem designs (Alloclassic, CLS, Bicontact and SL-Plus) were characterized using high-resolution 3D microscopy, and corrosion and fretting were rated using the Goldberg scoring scheme. Quantification of the taper surface topographies revealed a high variability in surface characteristics between threaded stem tapers: Alloclassic and CLS tapers feature deeply threaded trapezoid-shaped profiles with thread heights over 65 µm. The sawtooth-shaped Bicontact and triangular SL-Plus taper are characterized by low thread heights below 14 µm. Significantly lower corrosion and fretting scores were observed in lightly threaded compared to deeply threaded tapers in ceramic head combinations. No significant differences in corrosion or fretting scores with thread height were found in pairings with metal heads. Understanding the relationship between stem taper surface topography and the formation of corrosion and fretting could help to improve the performance of modern THAs and lead to longer-lasting clinical results.
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Affiliation(s)
- Kilian Elia Stockhausen
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 55a, 22529, Hamburg, Germany
| | - Christoph Riedel
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 55a, 22529, Hamburg, Germany
| | - Alex Victoria Belinski
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 55a, 22529, Hamburg, Germany.,Department of Mechanical Engineering, University of California, 6141 Etcheverry Hall, Berkeley, CA, USA
| | - Dorothea Rothe
- Department of Orthopedic Surgery, Helios ENDO-Klinik, Holstenstraße 2, 22767, Hamburg, Germany
| | - Thorsten Gehrke
- Department of Orthopedic Surgery, Helios ENDO-Klinik, Holstenstraße 2, 22767, Hamburg, Germany
| | - Felix Klebig
- Department of Orthopedic Surgery, Helios ENDO-Klinik, Holstenstraße 2, 22767, Hamburg, Germany
| | - Matthias Gebauer
- Department of Orthopedic Surgery, Helios ENDO-Klinik, Holstenstraße 2, 22767, Hamburg, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 55a, 22529, Hamburg, Germany
| | - Mustafa Citak
- Department of Orthopedic Surgery, Helios ENDO-Klinik, Holstenstraße 2, 22767, Hamburg, Germany
| | - Björn Busse
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 55a, 22529, Hamburg, Germany. .,Interdisciplinary Competence Center for Interface Research (ICCIR), Martinistr. 52, 20251, Hamburg, Germany. .,Forum Medical Technology Health Hamburg (FMTHH), Butenfeld 34, 22529, Hamburg, Germany.
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Jandl NM, von Kroge S, Stürznickel J, Baranowsky A, Stockhausen KE, Mushumba H, Beil FT, Püschel K, Amling M, Rolvien T. Large osteocyte lacunae in iliac crest infantile bone are not associated with impaired mineral distribution or signs of osteocytic osteolysis. Bone 2020; 135:115324. [PMID: 32198110 DOI: 10.1016/j.bone.2020.115324] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2019] [Revised: 02/29/2020] [Accepted: 03/16/2020] [Indexed: 12/13/2022]
Abstract
The enlargement of osteocyte lacunae via osteocytic osteolysis was previously detected in situations of increased calcium demand (e.g., lactation, vitamin D deficiency). However, it is unclear whether similar processes occur also in the growing infantile skeleton and how this is linked to the mineral distribution within the bone matrix. Human iliac crest biopsies of 30 subjects (0-6 months, n = 14; 2-8 years, n = 6 and 18-25 years, n = 10) were acquired. Bone microarchitecture was assessed by micro-CT, while cellular bone histomorphometry was performed on undecalcified histological sections. Quantitative backscattered electron imaging (qBEI) was conducted to determine the bone mineral density distribution (BMDD) as well as osteocyte lacunar size and density. We additionally evaluated cathepsin K positive osteocytes using immunohistochemistry. Infantile bone was characterized by various signs of ongoing bone development such as higher bone (re)modeling, lower cortical and trabecular thickness compared to young adults. Importantly, a significantly higher osteocyte lacunar density and increased lacunar area were detected. Large osteocyte lacunae were associated with a more heterogeneous bone mineral density distribution of the trabecular bone matrix due to the presence of hypermineralized cartilage remnants, whereas the mean mineralization (i.e., CaMean) was not different in infantile bone. Absence of cathepsin K expression in osteocyte lacunae indicated nonexistent osteocytic osteolysis. Taken together, we demonstrated that the overall mineralization distribution in infantile bone is not altered compared to young adults besides high trabecular mineralization heterogeneity. Our study also provides important reference values for bone microstructure, BMDD and osteocyte characteristics in infants, children and young adults. Infantile bone displays large osteocyte lacunae indicating a developmental phenomenon rather than osteocytic osteolysis. Larger osteocytes may have superior mechanosensory abilities to enable bone adaption during growth.
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Affiliation(s)
- Nico Maximilian Jandl
- Department of Orthopedics, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany; Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529 Hamburg, Germany
| | - Simon von Kroge
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529 Hamburg, Germany
| | - Julian Stürznickel
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529 Hamburg, Germany
| | - Anke Baranowsky
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529 Hamburg, Germany
| | - Kilian Elia Stockhausen
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529 Hamburg, Germany
| | - Herbert Mushumba
- Department of Legal Medicine, University Medical Center Hamburg-Eppendorf, Butenfeld 34, 22529 Hamburg, Germany
| | - Frank Timo Beil
- Department of Orthopedics, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Klaus Püschel
- Department of Legal Medicine, University Medical Center Hamburg-Eppendorf, Butenfeld 34, 22529 Hamburg, Germany
| | - Michael Amling
- Department of Orthopedics, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Tim Rolvien
- Department of Orthopedics, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany; Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529 Hamburg, Germany.
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