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Wang K, Wu Z, Gong C, Zhao G, Zhang H. TGF-β1 Inhibits Osteoclast Differentiation and Abnormal Angiogenesis in Intervertebral Disc Degeneration: Evidence from RNA Sequencing and Animal Studies. Orthop Surg 2024; 16:167-182. [PMID: 38014468 PMCID: PMC10782258 DOI: 10.1111/os.13912] [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: 02/08/2023] [Revised: 09/05/2023] [Accepted: 09/07/2023] [Indexed: 11/29/2023] Open
Abstract
OBJECTIVE Mechanisms involved in developing intervertebral disc degeneration (IDD) are poorly understood, thus making developing effective therapies difficult. This study aimed to suggest a possible molecular mechanism, based on transcriptome sequencing-identified transforming growth factor (TGF-β), underlying the effects on bone homeostasis in IDD. METHODS A mouse model for IDD was established. Transcriptome sequencing of nucleus pulposus tissue from mice (n = 3) identified differentially expressed mRNAs and key genes impacting bone homeostasis. A protein-protein interaction network pinpointed core genes. GO and KEGG analysis revealed gene functions. Expression levels of TGF-β1, tartrate-resistant acid phosphatase (TRAP), and cathepsin K (CTSK) were measured. Micro-CT evaluated vertebral structures and vascular imaging. Western Blot measured expression levels of Vegf, Opn, MMP3, and MMP13. Safranin O-Fast Green and TRAP staining were performed on intervertebral discs and endplates. RESULTS Transcriptomic analysis found 1790 differentially expressed mRNAs in IDD mice. Twenty-eight genes related to bone homeostasis in IDD were identified. TGF-β1 was confirmed as the core gene. GO and KEGG showed TGF-β1 regulates osteoclast markers like CTSK and TRAP through pathways including NF-κB and MAPK. Experimental validation revealed lower TGF-β1 expression in IDD mice than controls, and increased TRAP and CTSK expression. Micro-CT showed decreased bone mass and intervertebral disc space in IDD mice. Vascular imaging showed increased vascular volume in IDD cartilaginous endplates. Western blot displayed increased VEGF and OPN levels, but decreased MMP3 and MMP13 in IDD mice. Safranin O-fast green staining revealed severe IDD degeneration. However, TGF-β1 injection improved bone parameters in IDD mice. In vitro experiments confirmed TGF-β1 inhibits bone marrow macrophages differentiation into osteoclasts. CONCLUSION From our data, we conclude that TGF-β1 repressed osteoclast differentiation and aberrant bone-associated angiogenesis in cartilage endplates (EPs) to alleviate IDD, which may be instrumental for the therapeutic targeting of IDD.
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Affiliation(s)
- Keping Wang
- Department of OrthopedicsSecond Hospital of Lanzhou UniversityLanzhouChina
- Key Laboratory of Orthopedics Disease of Gansu ProvinceLanzhouChina
- Lanzhou UniversityLanzhouChina
| | - Zuolong Wu
- Department of OrthopedicsSecond Hospital of Lanzhou UniversityLanzhouChina
- Key Laboratory of Orthopedics Disease of Gansu ProvinceLanzhouChina
- Lanzhou UniversityLanzhouChina
| | - Chaoyang Gong
- Department of OrthopedicsSecond Hospital of Lanzhou UniversityLanzhouChina
- Key Laboratory of Orthopedics Disease of Gansu ProvinceLanzhouChina
- Lanzhou UniversityLanzhouChina
| | - Guanghai Zhao
- Department of OrthopedicsSecond Hospital of Lanzhou UniversityLanzhouChina
- Key Laboratory of Orthopedics Disease of Gansu ProvinceLanzhouChina
- Lanzhou UniversityLanzhouChina
| | - Haihong Zhang
- Department of OrthopedicsSecond Hospital of Lanzhou UniversityLanzhouChina
- Key Laboratory of Orthopedics Disease of Gansu ProvinceLanzhouChina
- Lanzhou UniversityLanzhouChina
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Li W, Zhao H, Zhou S, Xiong Z, Zhong W, Guan J, Liu T, Yang Y, Yu X. Does vertebral osteoporosis delay or accelerate lumbar disc degeneration? A systematic review. Osteoporos Int 2023; 34:1983-2002. [PMID: 37578509 PMCID: PMC10651704 DOI: 10.1007/s00198-023-06880-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 07/28/2023] [Indexed: 08/15/2023]
Abstract
The effect of vertebral osteoporosis on disc degeneration is still debated. The purpose of this study was to provide a systematic review of studies in this area to further reveal the relationship between the two. Relevant studies were searched in electronic databases, and studies were screened according to inclusion and exclusion criteria, and finally, basic information of the included studies was extracted and summarized. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A total of 34 publications spanning 24 years were included in our study. There were 19 clinical studies, including 12 prospective studies and 7 retrospective studies. Of these, 7 considered vertebral osteoporosis to be positively correlated with disc degeneration, 8 considered them to be negatively correlated, and 4 considered them to be uncorrelated. Two cadaveric studies were included, one considered the two to be negatively correlated and one considered them not to be correlated. Seven animal studies were included, of which five considered a positive correlation between vertebral osteoporosis and disc degeneration and two considered a negative correlation between the two. There were also 6 studies that used anti-osteoporosis drugs for intervention, all of them were animal studies. Five of them concluded that vertebral osteoporosis was positively associated with disc degeneration, and the remaining one concluded that there was no correlation between the two. Our systematic review shows that the majority of studies currently consider an association between vertebral osteoporosis and disc degeneration, but there is still a huge disagreement whether this association is positive or negative. Differences in observation time and follow-up time may be one of the reasons for the disagreement. A large number of clinical and basic studies are still needed in the future to further explore the relationship between the two.
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Affiliation(s)
- Wenhao Li
- Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, 100700, China
| | - He Zhao
- Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, 100700, China.
| | - Shibo Zhou
- Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, 100700, China
| | - Zhencheng Xiong
- West China Medical School, West China Hospital, Sichuan University, 610041, Chengdu, China
| | - Wenqing Zhong
- Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, 100700, China
| | - Jianbin Guan
- Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, 100700, China
| | - Tao Liu
- Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, 100700, China
| | - Yongdong Yang
- Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, 100700, China
| | - Xing Yu
- Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine, Beijing, 100700, China.
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McDonnell EE, Buckley CT. Consolidating and re-evaluating the human disc nutrient microenvironment. JOR Spine 2022; 5:e1192. [PMID: 35386756 PMCID: PMC8966889 DOI: 10.1002/jsp2.1192] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 12/14/2021] [Accepted: 01/07/2022] [Indexed: 12/19/2022] Open
Abstract
Background Despite exciting advances in regenerative medicine, cell‐based strategies for treating degenerative disc disease remain in their infancy. To maximize the potential for successful clinical translation, a more thorough understanding of the in vivo microenvironment is needed to better determine and predict how cell therapies will respond when administered in vivo. Aims This work aims to reflect on the in vivo nutrient microenvironment of the degenerating IVD through consolidating what has already been measured together with investigative in silico models. Materials and Methods This work uses in silico modeling, underpinned by more recent experimentally determined parameters of degeneration and nutrient transport from the literature, to re‐evaluate the current knowledge in terms of grade‐specific stages of degeneration. Results Through modeling only the metabolically active cell population, this work predicts slightly higher glucose concentrations compared to previous in silico models, while the predicted results show good agreement with previous intradiscal pH and oxygen measurements. Increasing calcification with degeneration limits nutrient transport into the IVD and initiates a build‐up of acidity; however, its effect is compensated somewhat by a reduction in diffusional distance due to decreasing disc height. Discussion This work advances in silico modeling through a strong foundation of experimentally determined grade‐specific input parameters. Taken together, pre‐existing measurements and predicted results suggest that metabolite concentrations may not be as critically low as commonly believed, with calcification not appearing to have a detrimental effect at stages of degeneration when cell therapies are an appropriate intervention. Conclusion Overall, our initiative is to provoke greater deliberation and consideration of the nutrient microenvironment when performing in vitro cell culture and cell therapy development. This work highlights urgency for robust experimental glucose measurements in healthy and degenerating IVDs, not only to validate in silico models but to significantly advance the field in fully elucidating the nutrient microenvironment and refining in vitro techniques to accelerate clinical translation.
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Affiliation(s)
- Emily E McDonnell
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin The University of Dublin Dublin Ireland.,Discipline of Mechanical, Manufacturing and Biomedical Engineering, School of Engineering, Trinity College Dublin The University of Dublin Dublin Ireland
| | - Conor T Buckley
- Trinity Centre for Biomedical Engineering, Trinity Biomedical Sciences Institute, Trinity College Dublin The University of Dublin Dublin Ireland.,Discipline of Mechanical, Manufacturing and Biomedical Engineering, School of Engineering, Trinity College Dublin The University of Dublin Dublin Ireland.,Advanced Materials and Bioengineering Research (AMBER) Centre, Royal College of Surgeons in Ireland & Trinity College Dublin The University of Dublin Dublin Ireland.,Tissue Engineering Research Group, Department of Anatomy and Regenerative Medicine Royal College of Surgeons in Ireland Dublin Ireland
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Xu H, Dong R, Zeng Q, Fang L, Ge Q, Xia C, Zhang P, Lv S, Zou Z, Wang P, Li J, Ruan H, Hu S, Wu C, Jin H, Tong P. Col9a2 gene deletion accelerates the degeneration of intervertebral discs. Exp Ther Med 2022; 23:207. [PMID: 35126710 PMCID: PMC8796617 DOI: 10.3892/etm.2022.11130] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 12/22/2021] [Indexed: 11/06/2022] Open
Affiliation(s)
- Huihui Xu
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Rui Dong
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Qinghe Zeng
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Liang Fang
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Qinwen Ge
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Chenjie Xia
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Peng Zhang
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Shuaijie Lv
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Zhen Zou
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Pinger Wang
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Ju Li
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Hongfeng Ruan
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Songfeng Hu
- Department of Orthopaedics and Traumatology, Shaoxing Hospital of Traditional Chinese Medicine, Shaoxing, Zhejiang 312000, P.R. China
| | - Chengliang Wu
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Hongting Jin
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Peijian Tong
- The First College of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
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Xiao ZF, He JB, Su GY, Chen MH, Hou Y, Chen SD, Lin DK. Osteoporosis of the vertebra and osteochondral remodeling of the endplate causes intervertebral disc degeneration in ovariectomized mice. Arthritis Res Ther 2018; 20:207. [PMID: 30201052 PMCID: PMC6131954 DOI: 10.1186/s13075-018-1701-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 08/15/2018] [Indexed: 12/21/2022] Open
Abstract
Background Studies on the relationship between osteoporosis and intervertebral disc degeneration (IVDD) are inconsistent. Therefore, we assessed whether IVDD is affected by vertebral osteoporosis in ovariectomized mice and investigated the underlying pathogenesis of IVDD related to osteoporosis. Methods Thirty healthy female C57BL/6 J mice aged 8 weeks were randomly divided into two groups: a control group (sham operation, n = 15) and an ovariectomy group (OVX; bilateral ovariectomy, n = 15). At 12 weeks after surgery, the bone quantity and microstructure in the lumbar vertebra and endplate as well as the volume of the L4/5 disc space were evaluated by microcomputed tomography (micro-CT). The occurrence and characteristic alterations of IVDD were identified via histopathological staining. The osteoclasts were detected using tartrate-resistant acid phosphatase (TRAP) staining. Type II collagen (Col II), osterix (OSX), osteopontin (OPN), and vascular endothelial growth factor (VEGF) expression in the intervertebral disc were detected by immunohistochemical analysis. Results OVX significantly increased the body weight and decreased the uterus weight. Micro-CT analysis showed that osteoporosis of the vertebra and osteochondral remodeling of the endplate were accompanied by an increase in the endplate porosity and a decrease in the disc volume in the OVX group. Likewise, histological evaluation revealed that IVDD occurred at 12 weeks after ovariectomy, with features of endochondral ossification of the endplate, loose and broken annulus fibrosus, and degeneration of nucleus pulposus. TRAP staining showed that numerous active osteoclasts appeared in the subchondral bone and cartilaginous endplate of OVX mice, whereas osteoclasts were rarely detected in control mice. Immunohistochemical analysis demonstrated that the expression of osterix was significantly increased, notably in the endplate of OVX mice. In addition, Col II was decreased in the ossification endplate and the degenerative annulus fibrosus, where OPN and VEGF expressions were elevated in OVX mice. Conclusions OVX induced vertebral osteoporosis and osteochondral remodeling of the cartilaginous endplate contributing to the angiogenesis and an increase in porosity of the bone-cartilage surface, and also affected the matrix metabolism which consequently had detrimental effects on the intervertebral disc. Our study suggests that preserving the structural integrity and the function of the adjacent structures, including the vertebrae and endplates, may protect the disc against degeneration. Electronic supplementary material The online version of this article (10.1186/s13075-018-1701-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zhi-Feng Xiao
- The Department of Spinal Surgery, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, No. 111, Dade Road, Yuexiu District, Guangzhou, 510120, China.,The Laboratory Affiliated to Orthopaedics and Traumatology of Chinese Medicine of Linnan Medical Research Center of Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, China.,Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, China
| | - Jian-Bo He
- The Department of Spinal Surgery, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, No. 111, Dade Road, Yuexiu District, Guangzhou, 510120, China.,The Laboratory Affiliated to Orthopaedics and Traumatology of Chinese Medicine of Linnan Medical Research Center of Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, China.,Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, China
| | - Guo-Yi Su
- The Department of Spinal Surgery, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, No. 111, Dade Road, Yuexiu District, Guangzhou, 510120, China.,Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, China
| | - Mei-Hui Chen
- The Department of Spinal Surgery, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, No. 111, Dade Road, Yuexiu District, Guangzhou, 510120, China.,The Laboratory Affiliated to Orthopaedics and Traumatology of Chinese Medicine of Linnan Medical Research Center of Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, China.,Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, China
| | - Yu Hou
- The Department of Spinal Surgery, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, No. 111, Dade Road, Yuexiu District, Guangzhou, 510120, China.,Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, China
| | - Shu-Dong Chen
- The Department of Spinal Surgery, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, No. 111, Dade Road, Yuexiu District, Guangzhou, 510120, China.,Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, China
| | - Ding-Kun Lin
- The Department of Spinal Surgery, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, No. 111, Dade Road, Yuexiu District, Guangzhou, 510120, China. .,The Laboratory Affiliated to Orthopaedics and Traumatology of Chinese Medicine of Linnan Medical Research Center of Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, China. .,Guangzhou University of Chinese Medicine, No. 12, Jichang Road, Baiyun District, Guangzhou, 510405, China.
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Buckley CT, Hoyland JA, Fujii K, Pandit A, Iatridis JC, Grad S. Critical aspects and challenges for intervertebral disc repair and regeneration-Harnessing advances in tissue engineering. JOR Spine 2018; 1:e1029. [PMID: 30895276 PMCID: PMC6400108 DOI: 10.1002/jsp2.1029] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 06/30/2018] [Accepted: 07/02/2018] [Indexed: 02/06/2023] Open
Abstract
Low back pain represents the highest burden of musculoskeletal diseases worldwide and intervertebral disc degeneration is frequently associated with this painful condition. Even though it remains challenging to clearly recognize generators of discogenic pain, tissue regeneration has been accepted as an effective treatment option with significant potential. Tissue engineering and regenerative medicine offer a plethora of exploratory pathways for functional repair or prevention of tissue breakdown. However, the intervertebral disc has extraordinary biological and mechanical demands that must be met to assure sustained success. This concise perspective review highlights the role of the disc microenvironment, mechanical and clinical design considerations, function vs mimicry in biomaterial‐based and cell engineering strategies, and potential constraints for clinical translation of regenerative therapies for the intervertebral disc.
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Affiliation(s)
- Conor T Buckley
- Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute Trinity College Dublin, The University of Dublin Dublin Ireland.,School of Engineering, Trinity College Dublin The University of Dublin Dublin Ireland.,Advanced Materials and Bioengineering Research (AMBER) Centre Royal College of Surgeons in Ireland & Trinity College Dublin, The University of Dublin Dublin Ireland
| | - Judith A Hoyland
- Division of Cell Matrix Biology and Regenerative Medicine University of Manchester Manchester UK.,NIHR Manchester Musculoskeletal Biomedical Research Unit, Central Manchester Foundation Trust Manchester Academic Health Science Centre Manchester UK
| | - Kengo Fujii
- Leni & Peter W. May Department of Orthopaedics Icahn School of Medicine at Mount Sinai New York New York USA.,Department of Orthopaedic Surgery University of Tsukuba Tsukuba Japan
| | - Abhay Pandit
- Centre for Research in Medical Devices (CÚRAM) National University of Ireland Galway Ireland
| | - James C Iatridis
- Leni & Peter W. May Department of Orthopaedics Icahn School of Medicine at Mount Sinai New York New York USA
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Gullbrand SE, Smith LJ, Smith HE, Mauck RL. Promise, progress, and problems in whole disc tissue engineering. JOR Spine 2018; 1:e1015. [PMID: 31463442 PMCID: PMC6686799 DOI: 10.1002/jsp2.1015] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 04/28/2018] [Accepted: 04/29/2018] [Indexed: 12/19/2022] Open
Abstract
Intervertebral disc degeneration is frequently implicated as a cause of back and neck pain, which are pervasive musculoskeletal complaints in modern society. For the treatment of end stage disc degeneration, replacement of the disc with a viable, tissue-engineered construct that mimics native disc structure and function is a promising alternative to fusion or mechanical arthroplasty techniques. Substantial progress has been made in the field of whole disc tissue engineering over the past decade, with a variety of innovative designs characterized both in vitro and in vivo in animal models. However, significant barriers to clinical translation remain, including construct size, cell source, culture technique, and the identification of appropriate animal models for preclinical evaluation. Here we review the clinical need for disc tissue engineering, the current state of the field, and the outstanding challenges that will need to be addressed by future work in this area.
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Affiliation(s)
- Sarah E. Gullbrand
- Translational Musculoskeletal Research CenterCorporal Michael J. Crescenz VA Medical CenterPhiladelphiaPennsylvania
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic SurgeryUniversity of PennsylvaniaPhiladelphiaPennsylvania
| | - Lachlan J. Smith
- Translational Musculoskeletal Research CenterCorporal Michael J. Crescenz VA Medical CenterPhiladelphiaPennsylvania
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic SurgeryUniversity of PennsylvaniaPhiladelphiaPennsylvania
- Department of NeurosurgeryUniversity of PennsylvaniaPhiladelphiaPennsylvania
| | - Harvey E. Smith
- Translational Musculoskeletal Research CenterCorporal Michael J. Crescenz VA Medical CenterPhiladelphiaPennsylvania
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic SurgeryUniversity of PennsylvaniaPhiladelphiaPennsylvania
- Department of NeurosurgeryUniversity of PennsylvaniaPhiladelphiaPennsylvania
| | - Robert L. Mauck
- Translational Musculoskeletal Research CenterCorporal Michael J. Crescenz VA Medical CenterPhiladelphiaPennsylvania
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic SurgeryUniversity of PennsylvaniaPhiladelphiaPennsylvania
- Department of BioengineeringUniversity of PennsylvaniaPhiladelphiaPennsylvania
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Wang Y, Yi XD, Li CD. The influence of artificial nucleus pulposus replacement on stress distribution in the cartilaginous endplate in a 3-dimensional finite element model of the lumbar intervertebral disc. Medicine (Baltimore) 2017; 96:e9149. [PMID: 29390319 PMCID: PMC5815731 DOI: 10.1097/md.0000000000009149] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE This study aimed to investigate the effects involved with the artificial nucleus pulposus (NP) replacement on stress distribution of the cartilaginous endplate (CEP) in a 3-dimensional lumbar intervertebral disc (IVD) model using a finite element (FE) analysis. METHODS A healthy male volunteer was recruited for the purposes of the study and a spiral computed tomography scan was subsequently conducted to obtain the data information in relation to the L4/5 motion segment. An FE model of the L4/5 motion segment constructed, on the basis of which degenerative IVD, IVD with NP removal, and IVD with NP replacement were in turn built. The stress distribution of the CEP and bulging of IVD were estimated using various motion states, including axial loading, forward flexion, backward extension, left axial rotation, and right axial rotation. RESULTS Under different motion states, the vertebral stress was higher in the degenerative IVD, the IVD with NP removal, and the IVD with NP replacement, in comparison to that of the normal IVD. Furthermore, a higher vertebral stress was detected in the degenerative IVD than the IVD with NP removal and the IVD with NP replacement. An even distribution of vertebral stress was observed in the IVD model with an artificial NP replacement, while the vertebral stress and bulging displacement were lower than after NP removal. Our findings provided confirmation that stress of the CEP was consistent with the vertebral stress. CONCLUSION This study provided evidence suggesting that NP replacement, vertebral stress, and bulging displacement are lower than that of degenerative IVD and IVD with NP removal under different motion states.
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Ye Y, Zhang C, Zhu K, Xu G, Han Z, Le Y. [Effect of Melittin on collagen type II expression of rat endplate chondrocytes induced by interleukin 1β]. ZHONGGUO XIU FU CHONG JIAN WAI KE ZA ZHI = ZHONGGUO XIUFU CHONGJIAN WAIKE ZAZHI = CHINESE JOURNAL OF REPARATIVE AND RECONSTRUCTIVE SURGERY 2017; 31:345-350. [PMID: 29806266 DOI: 10.7507/1002-1892.201609062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Objective To observe the effect of Melittin on collagen type II (Col-II) expression of rat endplate chondrocytes (EPCs) induced by interleukin 1β (IL-1β). Methods Primary EPCs from the lumbar vertebra of 4-week-old Sprague Dawley rats were cultured in vitro and identified by morphological observation, toluidine blue staining and Col-II immunofluorescence staining. Then, MTT assay was used to determine the optimal concentration of IL-1 and Melittin. Next, EPCs at passage 3 were randomly divided into 4 groups: no treatment was done in group A as control group; the optimal concentration of IL-1β, Melittin, and both IL-1β and Melittin were used in groups B, C, and D respectively. The expression of Col-II was detected by Western blot after 48 hours intervention. Results Under inverted microscope, the first generation EPCs were polygonal; cell proliferation decreased after fifth generation, and cell morphology changed into fusiform. The acidic mucosubstance in the cytoplasm (such as Aggrecan) was stained dark blue by toluidine blue. After marking Col-II by immunofluorescence, the positive expression of cytoskeleton (green fluorescence) could be observed. MTT assay showed that IL-1β and Melittin could inhibit the EPCs in a dose-dependent manner after intervention of 24 and 48 hours, and the optimal concentrations of IL-1β and Melittin intervention were 10 ng/mL and 1.0 μg/mL respectively. Compared with group A, the expression of Col-II was significantly reduced in group B, and was significantly increased in group C by Western blot assay, but there was no significant difference between group D and group A. The Col-II expression levels of groups A, B, C, and D were 0.991±0.024, 0.474±0.127, 1.913±0.350, and 1.159±0.297 respectively, showing significant difference between the other groups ( P<0.05) except between group A and group D ( P>0.05). Conclusion Melittin has a protective effect on endplate cartilage, and the research results provide experimental basis for the prevention and treatment of spinal degenerative disease.
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Affiliation(s)
- Yuchen Ye
- Department of Orthopedics, the First Affiliated Hospital of Bengbu Medical College, Bengbu Anhui, 233030, P.R.China
| | - Changchun Zhang
- Department of Orthopedics, the First Affiliated Hospital of Bengbu Medical College, Bengbu Anhui, 233030,
| | - Kun Zhu
- Department of Orthopedics, the First Affiliated Hospital of Bengbu Medical College, Bengbu Anhui, 233030, P.R.China
| | - Gang Xu
- Department of Orthopedics, the First Affiliated Hospital of Bengbu Medical College, Bengbu Anhui, 233030, P.R.China
| | - Zhongbing Han
- Department of Orthopedics, the First Affiliated Hospital of Bengbu Medical College, Bengbu Anhui, 233030, P.R.China
| | - Yi Le
- Department of Orthopedics, the First Affiliated Hospital of Bengbu Medical College, Bengbu Anhui, 233030, P.R.China
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The effects of intervertebral disc degeneration combined with osteoporosis on vascularization and microarchitecture of the endplate in rhesus monkeys. 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 2016; 25:2705-15. [PMID: 27220969 DOI: 10.1007/s00586-016-4593-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 04/27/2016] [Accepted: 04/27/2016] [Indexed: 01/03/2023]
Abstract
PURPOSE To evaluate the influence of osteoporosis on the microarchitecture and vascularization of the endplate in rhesus monkeys with or without intervertebral disc (IVD) degeneration using micro-computerized tomography (micro-CT), and to further analyze the correlation between osteoporosis and IVD degeneration. METHODS Twelve rhesus monkeys were randomly divided into the ovariectomy (OVX, n = 6) and the sham group (n = 6). The subchondral bone adjacent to the lumbar IVDs (from L4/5 to L6/7) of each monkey was randomly injected with 4 ml pingyangmycin (PYM) solution (1.5 mg/ml, PYM), or 4 ml phosphate buffered saline (PBS) as vehicle treatment, or exteriorized but not injected anything as control (Cntrl). Degenerative and osteoporotic processes were evaluated at different time points. Micro-CT and histology were performed to analyze microarchitecture, calcification area and vascularization of the endplate. RESULTS OVX resulted in significant decrease of bone mineral density (BMD). PYM injection induced progressively IVD degeneration, which was more progressive when combined with OVX. There was a negative correlation between BMD and Pfirrmann grade in the subgroups with PYM injection. The micro-CT analysis showed the combination of osteoporosis and IVD degeneration led to more calcification of endplate than any one thereof. The decrease of vascular volume percent in the endplate of the OVX-PYM subgroup was significantly greater than that in the Sham-PYM subgroup, both of which showed significant less vascularization compared to the other subgroups. CONCLUSION In conclusion the osteoporosis could accumulate the calcification and decrease the vascularization in the endplates adjacent to the degenerated IVDs, which subsequently exacerbated degeneration of the degenerated IVDs.
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Gullbrand SE, Peterson J, Mastropolo R, Lawrence JP, Lopes L, Lotz J, Ledet EH. Drug-induced changes to the vertebral endplate vasculature affect transport into the intervertebral disc in vivo. J Orthop Res 2014; 32:1694-700. [PMID: 25185989 DOI: 10.1002/jor.22716] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 07/21/2014] [Indexed: 02/04/2023]
Abstract
Intervertebral disc health is mediated in part by nutrient diffusion from the microvasculature in the adjacent subchondral bone. Evidence suggests that a reduction in nutrient diffusion contributes to disc degeneration, but the role of the microvasculature is unclear. The purpose of this study was to induce changes in the endplate microvasculature in vivo via pharmaceutical intervention and then correlate microvasculature characteristics to diffusion and disc health. New Zealand white rabbits were administered either nimodipine (to enhance microvessel density) or nicotine (to diminish microvessel density) daily for 8 weeks compared to controls. Trans-endplate diffusion and disc health were quantified using post-contrast enhanced magnetic resonance imaging (MRI). Histology was utilized to assess changes to the subchondral vasculature. Results indicate that nimodipine increased vessel area and vessel-endplate contact length, causing a significant increase in disc diffusion. Surprisingly, nicotine caused increases in vessel number and area but did not alter diffusion into the disc. The drug treatments did affect the microvasculature and diffusion, but the relationship between the two is complex and dependent on multiple factors which include vessel-endplate distance, and vessel-endplate contact length in addition to vessel density. Our data suggest that drugs can modulate these factors to augment or diminish small molecule transport.
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Affiliation(s)
- Sarah E Gullbrand
- Department of Biomedical Engineering, Rensselear Polytechnic Institute, JEC 7044, 110 8th Street, Troy, New York 1280
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Molecular interactions between human cartilaginous endplates and nucleus pulposus cells: a preliminary investigation. Spine (Phila Pa 1976) 2014; 39:1355-64. [PMID: 24831500 DOI: 10.1097/brs.0000000000000372] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Conditioned media (CM) of cartilaginous endplates (CEPs) of intervertebral discs were analyzed in a bioassay with regard to their influence on matrix turnover and inflammatory factors on nucleus pulposus (NP) cells of the same patient. CEP tissue underwent further histological and ultrastructural analysis. OBJECTIVE To identify possible interactions between the CEP and the disc via molecular factors that may influence disc matrix degradation and to determine degenerative changes of CEP tissue. SUMMARY OF BACKGROUND DATA Impaired endplate perme-ability due to degeneration and calcification is considered to be a key contributor to disc degeneration. An upregulation of metalloproteinases and inflammatory cytokines has been observed in degenerated intervertebral discs. Possibly, the CEP contributes to the regulation of disc matrix degradation via molecular interactions with the disc tissue. METHODS CEP and NP cells from the same patients (n = 6) were investigated in a bioassay with regard to their influence on matrix turnover and inflammatory factors. We determined gene expression of NP cells in alginate beads that were exposed to CM of CEP punches (CEP-CM) from the same patients. The CEP-CMs were analyzed by protein array for inflammatory cytokines. Further CEP samples underwent histological (n = 15) and ultrastructural analysis (n = 8) to determine alterations of cell and matrix structure. RESULTS NP cells exposed to their donor-corresponding CEP-CM significantly upregulated interleukins (IL-6, IL-8) and matrix metalloproteinase (MMP-3, MMP-13) expression, and significantly decreased aggrecan and collagen type 2 expression. Proinflammatory cytokines were identified in the CEP-CM. The occurrence of apoptotic cells and degraded matrix fragments varied strongly between donors. CONCLUSION Our results indicate interactions between the CEP and the NP tissue via molecular factors that upregulate matrix degrading enzymes and inflammatory cytokines and thereby influence the pathophysiology of disc degeneration. Ongoing investigations will further identify the regulative role of potential molecular factors that are responsible for these degenerative alterations. LEVEL OF EVIDENCE N/A.
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Malandrino A, Lacroix D, Hellmich C, Ito K, Ferguson SJ, Noailly J. The role of endplate poromechanical properties on the nutrient availability in the intervertebral disc. Osteoarthritis Cartilage 2014; 22:1053-60. [PMID: 24857972 DOI: 10.1016/j.joca.2014.05.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 04/15/2014] [Accepted: 05/07/2014] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To investigate the relevance of the human vertebral endplate poromechanics on the fluid and metabolic transport from and to the intervertebral disc (IVD) based on educated estimations of the poromechanical parameter values of the bony endplate (BEP). METHODS 50 micro-models of different BEP samples were generated from μCTs of lumbar vertebrae and allowed direct determination of porosity values. Permeability values were calculated by using the micro-models, through the simulation of permeation via computational fluid dynamics. These educated ranges of porosity and permeability values were used as inputs for mechano-transport simulations to assess their effect on both the distributions of metabolites within an IVD model and the poromechanical calculations within the cartilaginous part of the endplate i.e., the cartilage endplate (CEP). RESULTS BEP effective permeability was highly correlated to local variations of porosity (R(2) ≈ 0.88). Universal patterns between bone volume fraction and permeability arose from these results and from other experimental data in the literature. These variations in BEP permeability and porosity had negligible effects on the distributions of metabolites within the disc. In the CEP, the variability of the poromechanical properties of the BEP did not affect the predicted consolidation but induced higher fluid velocities. CONCLUSIONS The present paper provides the first sets of thoroughly identified BEP parameter values that can be further used in patient-specific poromechanical studies. Representing BEP structural changes through variations in poromechanical properties did not affect the diffusion of metabolites. However, attention might be paid to alterations in fluid velocities and cell mechano-sensing within the CEP.
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Affiliation(s)
- A Malandrino
- Biomechanics and Mechanobiology, Institute for Bioengineering of Catalonia, Barcelona, Spain
| | - D Lacroix
- INSIGNEO Institute for in silico Medicine, Department of Mechanical Engineering, University of Sheffield, Sheffield, UK
| | - C Hellmich
- Institute for Mechanics of Materials and Structures, Vienna University of Technology, Vienna, Austria
| | - K Ito
- Orthopedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - S J Ferguson
- Institute for Biomechanics, ETH, Zurich, Switzerland
| | - J Noailly
- Biomechanics and Mechanobiology, Institute for Bioengineering of Catalonia, Barcelona, Spain.
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Ding Y, Jiang J, Zhou J, Wu X, Huang Z, Chen J, Zhu Q. The effects of osteoporosis and disc degeneration on vertebral cartilage endplate lesions in rats. 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 2014; 23:1848-55. [PMID: 24806259 DOI: 10.1007/s00586-014-3324-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 04/17/2014] [Accepted: 04/18/2014] [Indexed: 01/08/2023]
Abstract
PURPOSE Evidence has shown that osteoporosis or intervertebral disc degeneration (IDD) led to cartilage endplate lesions (CEL), but their combined effects on the lesion remain unknown. This study developed an innovative rat model combined ovariectomy (OVX) and cervical muscle section (CMS), and aimed to evaluate the combined effects of osteoporosis and IDD on cartilage endplate lesions of cervical spine. METHODS Fifty-two Sprague-Dawley female rats were assigned randomly into four groups as follows: the sham group (n = 10) underwent sham surgery; the OVX group (n = 14) was subjected to bilateral ovariectomy; the CMS group (n = 14) had posterior paraspinal muscles cut from C2 to C7; the CMS-OVX group (n = 14) underwent the OVX and CMS surgeries consecutively. Samples of C6-C7 segments were harvested at 12, 18 and 24 weeks post-surgery. Micro-CT analysis was performed to evaluate the CEL, intervertebral disc height (IDH) and structural indices. Histological analysis with Safranine O/fast green stain and histological score were used to observe the characteristics of the degenerative discs. RESULTS Ovariectomy surgery resulted in significant changes of most structural indices of the C6 body, such as decrease of percent bone volume and number of bone trabecula at 12 weeks, and greater changes at 18 and 24 weeks. The CEL following CMS surgery was seen on the ventral, while the CEL in the OVX and sham groups on the peripheral. The CEL was greatest in the CMS-OVX group and significantly greater than that in the CMS and OVX groups at 12 and 18 weeks (P < 0.05). The CMS surgery resulted in significant IDH decrease at 12, 18 and 24 weeks (P < 0.05), while the OVX surgery resulted in mild IDH decrease when compared with the sham group. The IDH in the CMS-OVX group was significantly lower than that in the CMS group at 24 weeks (P < 0.05). Histological evaluation suggested cartilage endplate abrasion at 12 weeks, and in situ calcification at 18 and 24 weeks in the CMS and CMS-OVX groups. Disc degenerative scores were higher following CMS or OVX surgery, and correlated with the CEL and IDH (P < 0.01), respectively. CONCLUSIONS The present study suggested that a combination of OVX and CMS led to more lesion of cartilage endplate than any one thereof, as well as more decrease of IDH. The lesion and IDH decrease were associated with the disc degeneration levels. The cartilage endplate was worn out at the early stage and calcified in situ later. The results indicate that osteoporosis may deteriorate the disc degeneration at specific time.
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Affiliation(s)
- Yin Ding
- Department of Spine Surgery, Nanfang Hospital, Southern Medical University, 1838 North Guangzhou Avenue, 510515, Guangzhou, China
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Mattei TA. Osteoporosis delays intervertebral disc degeneration by increasing intradiscal diffusive transport of nutrients through both mechanical and vascular pathophysiological pathways. Med Hypotheses 2013; 80:582-6. [PMID: 23452642 DOI: 10.1016/j.mehy.2013.01.030] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 01/22/2013] [Accepted: 01/26/2013] [Indexed: 01/10/2023]
Abstract
Several studies have demonstrated an inverse correlation between osteoporosis and degenerative disc disease, so that patients with lower bone mass index, despite presenting greater risks of vertebral fractures, would paradoxically present delayed intervertebral disc degeneration. However the exact pathophysiological mechanisms underlying such phenomenon are not yet completely elucidated. In this article the author provides a general scheme to explain the causal relation between osteoporosis and delayed intervertebral disc degeneration by two main pathophysiological pathways: a vascular and a mechanical one. According to such model, osteoporosis positively affects disc nutrient diffusion through several mechanisms such as: increased endplate vascularization, decreased endplate resistance and decreased intradiscal strain. In the sequence a comprehensive review of the current literature on the issue is performed in order to provide a general overview about the current degree of evidence about the role of each factor postulated to be involved in such pathophysiological scheme. Finally the author provides overall directions for future research on the issue with special attention to the causal links which are supported by weak scientific evidence or by evidence from single studies.
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Affiliation(s)
- Tobias A Mattei
- Department of Neurosurgery, University of Illinois at Peoria, Peoria, IL 61603, USA.
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Boubriak OA, Watson N, Sivan SS, Stubbens N, Urban JPG. Factors regulating viable cell density in the intervertebral disc: blood supply in relation to disc height. J Anat 2013; 222:341-8. [PMID: 23311982 DOI: 10.1111/joa.12022] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2012] [Indexed: 01/20/2023] Open
Abstract
The intervertebral disc is an avascular tissue, maintained by a small population of cells that obtain nutrients mainly by diffusion from capillaries at the disc-vertebral body interface. Loss of this nutrient supply is thought to lead to disc degeneration, but how nutrient supply influences viable cell density is unclear. We investigated two factors that influence nutrient delivery to disc cells and hence cell viability: disc height and blood supply. We used bovine caudal discs as our model as these show a gradation in disc height. We found that although disc height varied twofold from the largest to the smallest disc studied, it had no significant effect on cell density, unlike the situation found in articular cartilage. The density of blood vessels supplying the discs was markedly greater for the largest disc than the smallest disc, as was the density of pores allowing capillary penetration through the bony endplate. Results indicate that changes in blood vessels in the vertebral bodies supplying the disc, as well as changes in endplate architecture appear to influence density of cells in intervertebral discs.
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Affiliation(s)
- Olga A Boubriak
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
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Intervertebral disk nutrition: a review of factors influencing concentrations of nutrients and metabolites. Orthop Clin North Am 2011; 42:465-77, vii. [PMID: 21944584 DOI: 10.1016/j.ocl.2011.07.010] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The biomechanical behavior of the intervertebral disk ultimately depends on the viability and activity of a small population of resident cells that make and maintain the disk's extracellular matrix. Nutrients that support these cells are supplied by the blood vessels at the disks' margins and diffuse through the matrix of the avascular disk to the cells. This article reviews pathways of nutrient supply to these cells; examines factors that may interrupt these pathways, and discusses consequences for disk cell survival, disk degeneration, and disk repair.
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Rutges JPHJ, Jagt van der OP, Oner FC, Verbout AJ, Castelein RJM, Kummer JA, Weinans H, Creemers LB, Dhert WJA. Micro-CT quantification of subchondral endplate changes in intervertebral disc degeneration. Osteoarthritis Cartilage 2011; 19:89-95. [PMID: 20950699 DOI: 10.1016/j.joca.2010.09.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 09/15/2010] [Accepted: 09/24/2010] [Indexed: 02/02/2023]
Abstract
BACKGROUND The intervertebral disc (IVD) is dependent on nutrient provision through a cartilage layer with underlying subchondral bone, analogous to joint cartilage. In the joint, subchondral bone remodeling has been associated with osteoarthritis (OA) progression due to compromised nutrient and gas diffusion and reduced structural support of the overlaying cartilage. However, subchondral bone changes in IVD degeneration have never been quantified before. OBJECTIVE The aim of this study is to determine the subchondral bone changes at different stages of IVD degeneration by micro-CT. METHODS Twenty-seven IVDs including the adjacent vertebral endplates were obtained at autopsy. Midsagittal slices, graded according the Thompson score, were scanned. Per scan 12 standardized cylindrical volumes of interest (VOI) were selected. Six VOIs contained the bony endplate and trabeculae (endplate VOIs) and six accompanying VOIs only contained trabecular bone (vertebral VOIs). Bone volume as percentage of the total volume (BV/TV) of the VOI, trabecular thickness (TrTh) and connectivity density (CD) were determined. RESULTS An increase in BV/TV and TrTh was found in endplate VOIs of IVDs with higher Thompson score whereas these values remained stable or decreased in the vertebral VOIs. CONCLUSION The increase in bone volume combined with the increase in TrTh in endplate VOIs strongly suggest that the subchondral endplate condenses to a more dense structure in degenerated IVDs. This may negatively influence the diffusion and nutrition of the IVD. The endplate differences between intact and mild degenerative IVDs (grade II) indicate an early association of subchondral endplate changes with IVD degeneration.
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Affiliation(s)
- J P H J Rutges
- Dept. Orthopaedics, University Medical Center Utrecht, Utrecht, The Netherlands.
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Remodelling of vertebral endplate subchondral bone in scoliosis: a micro-CT analysis in a porcine model. Clin Biomech (Bristol, Avon) 2010; 25:636-41. [PMID: 20605291 DOI: 10.1016/j.clinbiomech.2010.04.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Revised: 04/27/2010] [Accepted: 04/27/2010] [Indexed: 02/07/2023]
Abstract
BACKGROUND Disc degeneration has been correlated with alteration of bone density of adjacent vertebral bodies. Abnormal mechanical loading appears in scoliosis as compared to normal spines. How vertebral endplate was remodelled in scoliosis is not well understood. METHODS We conducted a micro-CT analysis of subchondral bone of the vertebral endplate at the curve apex in a porcine scoliosis model. Two adjacent thoracic T(5)-T(6) and lumbar L(1)-L(2) levels were instrumented in six four-week-old pigs with a custom offset implant connected by a flexible stainless steel wire. Two months after implantation, three cylindrical specimens were harvested into the vertebral endplate of each of the scoliosis levels: centre, convexity and concavity, and from the dorsal T(9)-T(10) vertebral units obtained from nine three-month-old non-instrumented pigs used as controls. Micro-CT analysis was carried out on each specimen. FINDINGS In the concavity of the scoliotic spine, bone volume fraction, trabecular thickness, and trabecular separation significantly increased whereas in the convexity, only trabecular separation increased. Connectivity index and trabecular number decreased significantly. INTERPRETATION This was the first micro-CT study of subchondral bone microarchitecture of the scoliotic vertebral end plate. At the curve apex, increased compression in the concavity induced an osteogenic process. In the convexity, diminished compression caused an osteolytic process with a local resorption. Clinically, the unbalanced tissue remodelling could play a role in the convective and diffusive transports into the end plate, which is of prime importance for the segment homeostasis in scoliosis treatment with or without surgery.
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