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Wilke HJ, Sciortino V. The past, present, and the future of disc nucleus replacement. A systematic review of a large diversity of ideas and experiences. Biomaterials 2024; 312:122717. [PMID: 39121730 DOI: 10.1016/j.biomaterials.2024.122717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 07/10/2024] [Accepted: 07/26/2024] [Indexed: 08/12/2024]
Abstract
Disc nucleus replacement (NR) is a challenging surgical technique used as a medical treatment for early-stage disc herniation to restore disc height and the biomechanical function of a motion segment, which may reduce low back pain. The surgical procedure involves the removal and replacement of the degenerated nucleus pulposus with a substitute by accessing the annulus fibrosos via a created hole. Over the decades, nucleus replacement has been an important issue, leading to the development of different substitute alternatives. The first ideas are dated to the 1950s and since then, more than a hundred nucleus replacement concepts can be identified. There were numerous attempts and several clinical trials; however, after more than 70 years of research, no gold standard for nucleus pulposus replacement has been identified. This review aims to collect the different nucleus replacements reported in the literature, thus understanding what failed, what could be improved and what are the opportunities for the future. A systematic review of the literature was performed using a keyword-based search on PubMed, Web of Science, and Scopus databases to detect all nucleus replacements presented in the past by clinicians and engineers. Several studies were extracted from which the main nucleus replacements over the years were investigated, including the ones that received CE mark, FDA approval, or IDE approval and, also those involved in clinical trials. A total of 116 studies were included in this review. The extracted data concern the nucleus replacements proposed over the years to create a historical background as complete as possible, including their mechanical and biomechanical characterization and the clinical trials conducted over the years. Nucleus disc arthroplasty has been explored for many years. Unfortunately, even today there is still nothing safe and definitive in this surgical practice. This review provides an overview of the nucleus replacement history. A breakthrough could be the improvements in technologies for the annulus fibrous closing or sealing and the tissue engineering and medical regenerative techniques which could certainly ensure a higher NR implantation success rate in the future of this clinical treatment. It is not yet clear what is the future of this clinical practice. Only scientific research can answer the question: is the nucleus replacement still a possible clinical solution?
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Affiliation(s)
- Hans-Joachim Wilke
- Institute of Orthopaedic Research and Biomechanics, Trauma Research Centre Ulm, Ulm University, Helmholtzstrabe 14, Ulm 89081, Germany.
| | - Vincenza Sciortino
- Institute of Orthopaedic Research and Biomechanics, Trauma Research Centre Ulm, Ulm University, Helmholtzstrabe 14, Ulm 89081, Germany; University of Palermo, Department of Engineering, Viale delle Scienze, 90128 Palermo, Italy
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Xiang D, Cui Y, Wan Z, Wang S, Peng L, Liao Z, Chen C, Liu W. Study on swelling, compression property and degradation stability of PVA composite hydrogels for artificial nucleus pulposus. J Mech Behav Biomed Mater 2022; 136:105496. [PMID: 36283297 DOI: 10.1016/j.jmbbm.2022.105496] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 09/27/2022] [Accepted: 09/27/2022] [Indexed: 11/06/2022]
Abstract
Artificial nucleus pulposus (ANP) replacement as an alternative to the treatment of cervical spondylosis aims to relieve pain and restore the normal cervical motion. In this study, the PVA/PVP and PVA/Pectin composite hydrogels (CH)s with different concentrations were prepared by the freezing-thawing process, and their performances were tested. The effect of different concentrations on both kinds of PVA CHs were evaluated and analysed. The results demonstrated that both kinds of CHs had good swelling property (¿190%), compressive stress-strain characteristic response and stable performance, and they were not easy to degrade (¡9%). The elastic modulus of the PVA/PVP CH was close to that of nucleus pulposus prosthesis, and the weight loss ratio of the PVA/PVP CH was lower than that of PVA/Pectin CH under load condition. Further, the experimental results showed that the PVA/PVP CH with 15 wt% solute and 1 wt% PVP content had the best comprehensive performance, which may provide significant advantages for use in future clinical application in replacing nucleus pulposus.
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Affiliation(s)
- Dingding Xiang
- School of Mechanical Engineering and Automation, Northeastern University, Shenyang, 110057, China; State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China; Key Laboratory for Precision and Non-Traditional Machining Technology of Ministry of Education, Dalian University of Technology, Dalian, 116081, China.
| | - Yangyang Cui
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China; Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China; Key Laboratory of Biomedical Materials and Implant Devices, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China
| | - Zhiping Wan
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Song Wang
- Key Laboratory of Biomedical Materials and Implant Devices, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China
| | - Lu Peng
- Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China; Key Laboratory of Biomedical Materials and Implant Devices, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China
| | - Zhenhua Liao
- Key Laboratory of Biomedical Materials and Implant Devices, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China
| | - Changsheng Chen
- Key Laboratory of Biomedical Materials and Implant Devices, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China.
| | - Weiqiang Liu
- State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China; Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China; Key Laboratory of Biomedical Materials and Implant Devices, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, China.
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Malli SE, Kumbhkarn P, Dewle A, Srivastava A. Evaluation of Tissue Engineering Approaches for Intervertebral Disc Regeneration in Relevant Animal Models. ACS APPLIED BIO MATERIALS 2021; 4:7721-7737. [PMID: 35006757 DOI: 10.1021/acsabm.1c00500] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Translation of tissue engineering strategies for the regeneration of intervertebral disc (IVD) requires a strong understanding of pathophysiology through the relevant animal model. There is no relevant animal model due to differences in disc anatomy, cellular composition, extracellular matrix components, disc physiology, and mechanical strength from humans. However, available animal models if used correctly could provide clinically relevant information for the translation into humans. In this review, we have investigated different types of strategies for the development of clinically relevant animal models to study biomaterials, cells, biomolecular or their combination in developing tissue engineering-based treatment strategies. Tissue engineering strategies that utilize various animal models for IVD regeneration are summarized and outcomes have been discussed. The understanding of animal models for the validation of regenerative approaches is employed to understand and treat the pathophysiology of degenerative disc disease (DDD) before proceeding for human trials. These animal models play an important role in building a therapeutic regime for IVD tissue regeneration, which can serve as a platform for clinical applications.
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Affiliation(s)
- Sweety Evangeli Malli
- Department of Medical Devices, National Institute of Pharmaceutical Education and Research-Ahmedabad (NIPER-Ahmedabad), Gandhinagar, Gujarat 382355, India
| | - Pranav Kumbhkarn
- Department of Medical Devices, National Institute of Pharmaceutical Education and Research-Ahmedabad (NIPER-Ahmedabad), Gandhinagar, Gujarat 382355, India
| | - Ankush Dewle
- Department of Medical Devices, National Institute of Pharmaceutical Education and Research-Ahmedabad (NIPER-Ahmedabad), Gandhinagar, Gujarat 382355, India
| | - Akshay Srivastava
- Department of Medical Devices, National Institute of Pharmaceutical Education and Research-Ahmedabad (NIPER-Ahmedabad), Gandhinagar, Gujarat 382355, India
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Fujioka T, Nakata K, Nakano Y, Nozue Y, Sugawara T, Konno N, Maeda S, Kamishina H. Accuracy and Efficacy of a Patient-Specific Drill Guide Template System for Lumbosacral Junction Fixation in Medium and Small Dogs: Cadaveric Study and Clinical Cases. Front Vet Sci 2020; 6:494. [PMID: 31998769 PMCID: PMC6964317 DOI: 10.3389/fvets.2019.00494] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 12/12/2019] [Indexed: 11/30/2022] Open
Abstract
Objectives: To develop drill guide templates as an intraoperative guide, and to evaluate the accuracy and safety of screw placement in the lumbosacral junction. Samples: Canine cadaveric specimens of the lumbosacral junction (n = 6), and clinical cases of lumbosacral instability (n = 3). Procedures: Computed tomography data of the lumbosacral region of cadaveric specimens and clinical cases were obtained. The optimum screw trajectories were determined and drill guide templates were fabricated using a three-dimensional printing system. Drill holes were made using the templates in cadaveric specimens and clinical cases, and lumbosacral fixation was performed in clinical cases. Computed tomography images were obtained to compare the planned and postoperative drill hole trajectories, and the accuracy and safety of drilling and screw placement in the lumbosacral junction were evaluated. Results: Thirty-six drill holes were made in cadaveric specimens. The overall mean drill hole deviation was 2.05 ± 1.32 mm. A total of 12 screws were placed in the lumbosacral junctions of three clinical cases. The overall mean drill hole deviation was 2.43 ± 1.09 mm. Clinical signs improved within 2 weeks in the clinical cases. All drill holes were completely located within the bone in cadaveric specimens and clinical cases. Conclusion and Clinical Relevance: The surgical procedures using the drill guide templates were performed safely with good clinical outcomes. The drill guide template system provided useful surgical guidance to safely and precisely perform screw placement for lumbosacral fixation surgery in small dogs.
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Affiliation(s)
- Toru Fujioka
- The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.,Ivy Animal Clinic, Okayama, Japan
| | - Kohei Nakata
- The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.,The Animal Medical Center of Gifu University, Gifu University, Gifu, Japan
| | - Yukiko Nakano
- The Animal Medical Center of Gifu University, Gifu University, Gifu, Japan
| | - Yuta Nozue
- The Animal Medical Center of Gifu University, Gifu University, Gifu, Japan
| | - Taku Sugawara
- Department of Spinal Surgery, Research Institute for Brain and Blood Vessels-Akita, Akita, Japan
| | | | - Sadatoshi Maeda
- The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.,The Animal Medical Center of Gifu University, Gifu University, Gifu, Japan
| | - Hiroaki Kamishina
- The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.,The Animal Medical Center of Gifu University, Gifu University, Gifu, Japan.,Center for Highly Advanced Integration of Nano and Life Sciences, Gifu University, Gifu, Japan
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Lee T, Lim TH, Lee SH, Kim JH, Hong J. Biomechanical function of a balloon nucleus pulposus replacement system: A human cadaveric spine study. J Orthop Res 2018; 36:167-173. [PMID: 28513885 DOI: 10.1002/jor.23607] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 05/08/2017] [Indexed: 02/04/2023]
Abstract
With recent advances in motion-sparing techniques in spine surgery, disc nucleus replacement (DNR) has been introduced as a viable method to restore the biomechanical functions of the spine. Several methods of DNR have been proposed in the literature. However, the risk of device migration or extrusion is a major issue that should be addressed for a successful DNR. DNR using a balloon nucleus (BN) filled with pressurized fluid may be capable of reducing such risks while preserving the advantages of DNR. The objective of this study was to investigate the biomechanical functionalities of the human cadaveric lumbar motion segments with a custom made BN filled with saline at internal fluid pressure of 0.3 or 0.6 MPa in terms of axial and rotational flexibilities of the L4-L5 motion segment. Axial flexibility was quantified by the axial displacement resulting from an axial compressive force of 400 N while the rotational flexibility by the range of motions determined as the rotational angles in response to a pure moment of 6.0 Nm in flexion, extension, and right- and left-lateral bending directions. These tests were performed successively on the motion segment in the following conditions: intact, post nucleotomy, implanting BN with 0.3 MPa, and BN with 0.6 MPa. The nucleotomy was found to significantly increase both the axial and rotational flexibilities while the implantation of the BN reduced the axial and rotational flexibilities to those of the intact segment. The axial and rotational flexibilities of the segment with the BN with 0.3 MPa were greater than those of the segment with the BN with 0.6 MPa. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:167-173, 2018.
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Affiliation(s)
- Taekyeong Lee
- Department of Control and Instrumentation Engineering, Korea University, 2511 Sejong-ro, Sejong City, 30019, Republic of Korea
| | - Tae-Hong Lim
- Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa
| | - Sang-Heon Lee
- Department of Physical Medicine and Rehabilitation, Anam Hospital, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Joo-Han Kim
- Department of Neurosurgery, Guro Hospital, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Junghwa Hong
- Department of Control and Instrumentation Engineering, Korea University, 2511 Sejong-ro, Sejong City, 30019, Republic of Korea.,Department of Medicine, College of Medicine, Korea University, Seoul, Republic of Korea
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Li Z, Lang G, Chen X, Sacks H, Mantzur C, Tropp U, Mader KT, Smallwood TC, Sammon C, Richards RG, Alini M, Grad S. Polyurethane scaffold with in situ swelling capacity for nucleus pulposus replacement. Biomaterials 2016; 84:196-209. [DOI: 10.1016/j.biomaterials.2016.01.040] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/15/2016] [Accepted: 01/19/2016] [Indexed: 12/18/2022]
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Detiger SEL, de Bakker JY, Emanuel KS, Schmitz M, Vergroesen PPA, van der Veen AJ, Mazel C, Smit TH. Translational challenges for the development of a novel nucleus pulposus substitute: Experimental results from biomechanical and in vivo studies. J Biomater Appl 2015; 30:983-94. [PMID: 26494611 DOI: 10.1177/0885328215611946] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Nucleus pulposus replacement therapy could offer a less invasive alternative to restore the function of moderately degenerated intervertebral discs than current potentially destructive surgical procedures. Numerous nucleus pulposus substitutes have already been investigated, to assess their applicability for intradiscal use. Still, the current choice of testing methods often does not lead to efficient translation into clinical application. In this paper, we present the evaluation of a novel nucleus pulposus substitute, consisting of a hydromed core and an electrospun envelope. We performed three mechanical evaluations and an in vivo pilot experiment. Initially, the swelling pressure of the implant was assessed in confined compression. Next, we incorporated the implant into mechanically damaged caprine lumbar intervertebral discs to determine biomechanical segment behaviour in bending and torsion. Subsequently, segments were serially tested in native, damaged and repaired conditions under dynamic axial compressive loading regimes in a loaded disc culture system. Finally, nucleus pulposus substitutes were implanted in a live goat spine using a transpedicular approach. In confined compression, nucleus pulposus samples as well as implants showed some load-bearing capacity, but the implant exhibited a much lower absolute pressure. In bending and torsion, we found that the nucleus pulposus substitute could partly restore the mechanical response of the disc. During dynamic axial compression in the loaded disc culture system, on the other hand, the implant was not able to recover axial compressive behaviour towards the healthy situation. Moreover, the nucleus pulposus substitutes did not remain in place in the in vivo situation but migrated out of the disc area. From these results, we conclude that implants may mimic native disc behaviour in simple mechanical tests, yet fail in other, more realistic set-ups. Therefore, we recommend that biomaterials for nucleus pulposus replacement be tested in testing modalities of increasing complexity and in their relevant anatomical surroundings, for a more reliable prediction of clinical potential.
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Affiliation(s)
- S E L Detiger
- Department of Orthopaedic Surgery, VU University Medical Center, Amsterdam, The Netherlands Center for Translational Regenerative Medicine (CTRM) and MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - J Y de Bakker
- Department of Orthopaedic Surgery, VU University Medical Center, Amsterdam, The Netherlands Center for Translational Regenerative Medicine (CTRM) and MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - K S Emanuel
- Department of Orthopaedic Surgery, VU University Medical Center, Amsterdam, The Netherlands Center for Translational Regenerative Medicine (CTRM) and MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - M Schmitz
- Department of Orthopaedic Surgery, VU University Medical Center, Amsterdam, The Netherlands Center for Translational Regenerative Medicine (CTRM) and MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - P P A Vergroesen
- Department of Orthopaedic Surgery, VU University Medical Center, Amsterdam, The Netherlands Center for Translational Regenerative Medicine (CTRM) and MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - A J van der Veen
- Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, The Netherlands
| | - C Mazel
- Department of Orthopaedic and Spine Surgery, Institute Mutualiste Montsouris, Paris, France
| | - T H Smit
- Department of Orthopaedic Surgery, VU University Medical Center, Amsterdam, The Netherlands Center for Translational Regenerative Medicine (CTRM) and MOVE Research Institute Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
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Early P, Mente P, Dillard S, Roe S. In vitro biomechanical evaluation of internal fixation techniques on the canine lumbosacral junction. PeerJ 2015; 3:e1094. [PMID: 26312169 PMCID: PMC4548529 DOI: 10.7717/peerj.1094] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 06/18/2015] [Indexed: 11/20/2022] Open
Abstract
Few biomechanical studies have evaluated the effect of internal stabilization techniques after decompressive surgery on the stability of the canine lumbosacral junction. The purpose of this canine cadaver study is to evaluate the stability of the canine lumbosacral (LS) spine in flexion and extension following laminectomy and discectomy and then stabilization with each of the three techniques: pins and polymethylmethacrylate (P/PMMA), two dorsal locking plates (SOP) or bilateral transarticular facet screws (FACET).Using a cantilever biomechanical system, bending moments were applied to the LS and range of motion (ROM) was recorded via a rotational potentiometer. With 3 Nm, the ROM (n = 4 in each group) for P/PMMA, SOP and FACET were 1.92 ± 0.96°, 2.56 ± 0.55°and 3.18 ± 1.14°, respectively. With moments up to 35 Nm, the P/PMMA specimens appeared stable. Sacroiliac motion in the SOP and FACET groups invalidated further comparisons. Each of the stabilization techniques (P/PMMA, SOP, and FACET) significantly decreased the range of motion in flexion and extension for low bending moments.
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Affiliation(s)
- Peter Early
- College of Veterinary Medicine, North Carolina State University , Raleigh, NC , USA
| | - Peter Mente
- Joint Department of Biomedical Engineering at the University of North Carolina Chapel Hill, North Carolina State University , Raleigh, NC , USA
| | | | - Simon Roe
- College of Veterinary Medicine, North Carolina State University , Raleigh, NC , USA
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Strange DGT, Tonsomboon K, Oyen ML. Mechanical behaviour of electrospun fibre-reinforced hydrogels. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2014; 25:681-690. [PMID: 24408274 DOI: 10.1007/s10856-013-5123-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 12/11/2013] [Indexed: 06/03/2023]
Abstract
Mechanically robust and biomimicking scaffolds are needed for structural engineering of tissues such as the intervertebral disc, which are prone to failure and incapable of natural healing. Here, the formation of thick, randomly aligned polycaprolactone electrospun fibre structures infiltrated with alginate is reported. The composites are characterised using both indentation and tensile testing and demonstrate substantially different tensile and compressive moduli. The composites are mechanically robust and exhibit large strains-to-failure, exhibiting toughening mechanisms observed in other composite material systems. The method presented here provides a way to create large-scale biomimetic scaffolds that more closely mimic the composite structure of natural tissue, with tuneable tensile and compressive properties via the fibre and matrix phases, respectively.
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Affiliation(s)
- Daniel G T Strange
- Engineering Department, Cambridge University, Trumpington St., Cambridge, CB2 1PZ, UK
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Early P, Mente P, Dillard S, Roe S. In vitro biomechanical comparison of the flexion/extension mobility of the canine lumbosacral junction before and after dorsal laminectomy and partial discectomy. Vet J 2013; 196:533-5. [DOI: 10.1016/j.tvjl.2012.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 11/07/2012] [Accepted: 11/10/2012] [Indexed: 10/27/2022]
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Detiger SEL, Hoogendoorn RJW, van der Veen AJ, van Royen BJ, Helder MN, Koenderink GH, Smit TH. Biomechanical and rheological characterization of mild intervertebral disc degeneration in a large animal model. J Orthop Res 2013; 31:703-9. [PMID: 23255234 DOI: 10.1002/jor.22296] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 11/26/2012] [Indexed: 02/04/2023]
Abstract
Biomechanical properties of healthy and degenerated nucleus pulposus (NP) are thought to be important for future regenerative strategies for intervertebral disc (IVD) repair. However, which properties are pivotal as design criteria when developing NP replacement materials is ill understood. Therefore, we determined and compared segmental biomechanics and NP viscoelastic properties in normal and mildly degenerated discs. In eight goats, three lumbar IVDs were chemically degenerated using chondroitinase ABC (CABC), confirmed with radiography and MRI after euthanasia 12 weeks post-operative. Neutral zone (NZ) stiffness and range of motion (ROM) were determined sagitally, laterally, and rotationally for each spinal motion segment (SMS) using a mechanical testing device. NPs were isolated for oscillatory shear experiments; elastic and viscous shear moduli followed from the ratio between shear stress and strain. Water content was quantified by weighing before and after freeze-drying. Disc height on radiographs and signal intensity on MRI decreased (6% and 22%, respectively, p < 0.01) after CABC treatment, confirming that chemical degeneration provides a good model of disc degeneration. Furthermore, CABC-injected IVDs had significantly lower NZ stiffness and larger ROM in lateral bending (LB) and axial rotation (AR) than controls. Rheometry consistently revealed significantly lower (10-12%) viscoelastic moduli after mild degeneration within goats, though the inter-animal differences were relatively large (complex modulus ∼12 to 41 kPa). Relative water content in the NP was unaffected by CABC, remaining at ∼75%. These observations suggest that viscoelastic properties have a marginal influence on mechanical behavior of the whole SMS. Therefore, when developing replacement materials the focus should be on other design criteria, such as biochemical cues and swelling pressure.
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Affiliation(s)
- Suzanne E L Detiger
- Department of Orthopaedic Surgery, VU University Medical Center, Amsterdam, The Netherlands
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Bergknut N, Smolders LA, Grinwis GCM, Hagman R, Lagerstedt AS, Hazewinkel HAW, Tryfonidou MA, Meij BP. Intervertebral disc degeneration in the dog. Part 1: Anatomy and physiology of the intervertebral disc and characteristics of intervertebral disc degeneration. Vet J 2012. [PMID: 23177522 DOI: 10.1016/j.tvjl.2012.10.024] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Intervertebral disc (IVD) degeneration is common in dogs and can give rise to a number of diseases, such as IVD herniation, cervical spondylomyelopathy, and degenerative lumbosacral stenosis. Although there have been many reports and reviews on the clinical aspects of canine IVD disease, few reports have discussed and reviewed the process of IVD degeneration. In this first part of a two-part review, the anatomy, physiology, histopathology, and biochemical and biomechanical characteristics of the healthy and degenerated IVD are described. In Part 2, the aspects of IVD degeneration in chondrodystrophic and non-chondrodystrophic dog breeds are discussed in depth.
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Affiliation(s)
- Niklas Bergknut
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, 3508 TD Utrecht, The Netherlands.
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Kranenburg HJC, Meij BP, Onis D, van der Veen AJ, Saralidze K, Smolders LA, Huizinga JG, Knetsch ML, Luijten PR, Visser F, Voorhout G, Dhert WJ, Hazewinkel HA, Koole LH. Design, synthesis, imaging, and biomechanics of a softness-gradient hydrogel nucleus pulposus prosthesis in a canine lumbar spine model. J Biomed Mater Res B Appl Biomater 2012; 100:2148-55. [DOI: 10.1002/jbm.b.32780] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 06/11/2012] [Accepted: 06/15/2012] [Indexed: 11/08/2022]
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