1
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Rahman T, Kibble MJ, Harbert G, Smith N, Brewer E, Schaer TP, Newell N. Comparison of four in vitro test methods to assess nucleus pulposus replacement device expulsion risk. JOR Spine 2024; 7:e1332. [PMID: 38655007 PMCID: PMC11037461 DOI: 10.1002/jsp2.1332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 03/22/2024] [Accepted: 03/27/2024] [Indexed: 04/26/2024] Open
Abstract
Background Nucleus replacement devices (NRDs) are not routinely used in clinic, predominantly due to the risk of device expulsion. Rigorous in vitro testing may enable failure mechanisms to be identified prior to clinical trials; however, current testing standards do not specify a particular expulsion test. Multiple methods have therefore been developed, complicating comparisons between NRD designs. Thus, this study assessed the effectiveness of four previously reported expulsion testing protocols; hula-hoop (Protocol 1), adapted hula-hoop (Protocol 2), eccentric cycling (Protocol 3), and ramp to failure (Protocol 4), applied to two NRDs, one preformed and one in situ curing. Methods Nucleus material was removed from 40 bovine tail intervertebral disks. A NRD was inserted posteriorly into each cavity and the disks were subjected to one of four expulsion protocols. Results NRD response was dependent on both the NRD design and the loading protocol. Protocol 1 resulted in higher migration and earlier failure rates compared to Protocol 2 in both NRDs. The preformed NRD was more likely to migrate when protocols incorporated rotation. The NRDs had equal migration (60%) and expulsion (60%) rates when using unilateral bending and ramp testing. Combining the results of multiple tests revealed complimentary information regarding the NRD response. Conclusions Adapted hula-hoop (Protocol 2) and ramp to failure (Protocol 4), combined with fluoroscopic analysis, revealed complimentary insights regarding migration and failure risk. Therefore, when adopting the surgical approach and animal model used in this study, it is recommended that NRD performance be assessed using both a cyclic and ramp loading protocol.
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Affiliation(s)
- Tamanna Rahman
- Department of BioengineeringImperial College LondonLondonUK
- Biomechanics Group, Department of Mechanical EngineeringImperial College LondonLondonUK
| | | | | | - Nigel Smith
- Division of Surgery and Interventional ScienceUniversity College LondonStanmoreUK
| | - Erik Brewer
- Department of Biomedical EngineeringRowan UniversityGlassboroNew JerseyUSA
| | - Thomas P. Schaer
- Department of Clinical Studies New Bolton CenterUniversity of Pennsylvania School of Veterinary MedicineKennett SquarePennsylvaniaUSA
| | - Nicolas Newell
- Department of BioengineeringImperial College LondonLondonUK
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2
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Combination of ultra-purified stem cells with an in situ-forming bioresorbable gel enhances intervertebral disc regeneration. EBioMedicine 2022; 76:103845. [PMID: 35085848 PMCID: PMC8801983 DOI: 10.1016/j.ebiom.2022.103845] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 12/18/2021] [Accepted: 01/13/2022] [Indexed: 12/14/2022] Open
Abstract
Background Lumbar intervertebral disc (IVD) herniations are associated with significant disability. Discectomy is the conventional treatment option for IVD herniations but causes a defect in the IVD, which has low self-repair ability, thereby representing a risk of further IVD degeneration. An acellular, bioresorbable, and good manufacturing practice (GMP)-compliant in situ-forming gel, which corrects discectomy-associated IVD defects and prevents further IVD degeneration had been developed. However, this acellular matrix-based strategy has certain limitations, particularly in elderly patients, whose tissues have low self-repair ability. The aim of this study was to investigate the therapeutic efficacy of using a combination of newly-developed, ultra-purified, GMP-compliant, human bone marrow mesenchymal stem cells (rapidly expanding clones; RECs) and the gel for IVD regeneration after discectomy in a sheep model of severe IVD degeneration. Methods RECs and nucleus pulposus cells (NPCs) were co-cultured in the gel. In addition, RECs combined with the gel were implanted into IVDs following discectomy in sheep with degenerated IVDs. Findings Gene expression of NPC markers, growth factors, and extracellular matrix increased significantly in the co-culture compared to that in each mono-culture. The REC and gel combination enhanced IVD regeneration after discectomy (up to 24 weeks) in the severe IVD degeneration sheep model. Interpretation These findings demonstrate the translational potential of the combination of RECs with an in situ-forming gel for the treatment of herniations in degenerative human IVDs. Funding Ministry of Education, Culture, Sports, Science, and Technology of Japan, Japan Agency for Medical Research and Development, and the Mochida Pharmaceutical Co., Ltd.
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3
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Culbert MP, Warren JP, Dixon AR, Fermor HL, Beales PA, Wilcox RK. Evaluation of injectable nucleus augmentation materials for the treatment of intervertebral disc degeneration. Biomater Sci 2021; 10:874-891. [PMID: 34951410 DOI: 10.1039/d1bm01589c] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Back pain affects a person's health and mobility as well as being associated with large health and social costs. Lower back pain is frequently caused by degeneration of the intervertebral disc. Current operative and non-operative treatments are often ineffective and expensive. Nucleus augmentation is designed to be a minimally invasive method of restoring the disc to its native healthy state by restoring the disc height, and mechanical and/or biological properties. The majority of the candidate materials for nucleus augmentation are injectable hydrogels. In this review, we examine the materials that are currently under investigation for nucleus augmentation, and compare their ability to meet the design requirements for this application. Specifically, the delivery of the material into the disc, the mechanical properties of the material and the biological compatibility are examined. Recommendations for future testing are also made.
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Affiliation(s)
- Matthew P Culbert
- Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, UK, LS2 9JT.
| | - James P Warren
- Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, UK, LS2 9JT.
| | - Andrew R Dixon
- Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, UK, LS2 9JT.
| | - Hazel L Fermor
- Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, UK, LS2 9JT.
| | - Paul A Beales
- School of Chemistry, Astbury Centre for Structural Molecular Biology and Bragg Centre for Materials Research, University of Leeds, UK, LS2 9JT
| | - Ruth K Wilcox
- Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, UK, LS2 9JT.
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4
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Dixon AR, Warren JP, Culbert MP, Mengoni M, Wilcox RK. Review of in vitro mechanical testing for intervertebral disc injectable biomaterials. J Mech Behav Biomed Mater 2021; 123:104703. [PMID: 34365096 DOI: 10.1016/j.jmbbm.2021.104703] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 06/22/2021] [Accepted: 07/03/2021] [Indexed: 01/17/2023]
Abstract
Many early stage interventions for intervertebral disc degeneration are under development involving injection of a biomaterial into the affected tissue. Due to the complex mechanical behaviour of the intervertebral disc, there are challenges in comprehensively evaluating the performance of these injectable biomaterials in vitro. The aim of this review was to examine the different methods that have been developed to mechanically test injectable intervertebral disc biomaterials in an in vitro disc model. Testing methods were examined with emphasis on overall protocol, artificial degeneration method, mechanical testing regimes and injection delivery. Specifically, the effects of these factors on the evaluation of different aspects of device performance was assessed. Broad testing protocols varied between studies and enabled evaluation of different aspects of an injectable treatment. Studies employed artificial degeneration methodologies which were either on a macro scale through mechanical means or on a microscale with biochemical means. Mechanical loading regimes differed greatly across studies, with load being either held constant, ramped to failure, or applied cyclically, with large variability on all loading parameters. Evaluation of the risk of herniation was possible by utilising ramped loading, whereas cyclic loading enabled the examination of the restoration of mechanical behaviour for initial screening of biomaterials and surgical technique optimisation studies. However, there are large variations in the duration or tests, and further work is needed to define an appropriate number of cycles to standardise this type of testing. Biomaterial delivery was controlled by set volume or haptic feedback, and future investigations should generate evidence applying physiological loading during injection and normalisation of injection parameters based on disc size. Based on the reviewed articles and considering clinical risks, a series of recommendations have been made for future intervertebral disc mechanical testing.
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Affiliation(s)
- A R Dixon
- University of Leeds, Institute of Medical and Biological Engineering, Leeds, LS2 9JT, United Kingdom.
| | - J P Warren
- University of Leeds, Institute of Medical and Biological Engineering, Leeds, LS2 9JT, United Kingdom
| | - M P Culbert
- University of Leeds, Institute of Medical and Biological Engineering, Leeds, LS2 9JT, United Kingdom
| | - M Mengoni
- University of Leeds, Institute of Medical and Biological Engineering, Leeds, LS2 9JT, United Kingdom
| | - R K Wilcox
- University of Leeds, Institute of Medical and Biological Engineering, Leeds, LS2 9JT, United Kingdom.
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5
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Sloan SR, Wipplinger C, Kirnaz S, Navarro-Ramirez R, Schmidt F, McCloskey D, Pannellini T, Schiavinato A, Härtl R, Bonassar LJ. Combined nucleus pulposus augmentation and annulus fibrosus repair prevents acute intervertebral disc degeneration after discectomy. Sci Transl Med 2021; 12:12/534/eaay2380. [PMID: 32161108 DOI: 10.1126/scitranslmed.aay2380] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 02/10/2020] [Indexed: 12/12/2022]
Abstract
Tissue-engineered approaches for the treatment of early-stage intervertebral disc degeneration have shown promise in preclinical studies. However, none of these therapies has been approved for clinical use, in part because each therapy targets only one aspect of the intervertebral disc's composite structure. At present, there is no reliable method to prevent intervertebral disc degeneration after herniation and subsequent discectomy. Here, we demonstrate the prevention of degeneration and maintenance of mechanical function in the ovine lumbar spine after discectomy by combining strategies for nucleus pulposus augmentation using hyaluronic acid injection and repair of the annulus fibrosus using a photocrosslinked collagen patch. This combined approach healed annulus fibrosus defects, restored nucleus pulposus hydration, and maintained native torsional and compressive stiffness up to 6 weeks after injury. These data demonstrate the necessity of a combined strategy for arresting intervertebral disc degeneration and support further translation of combinatorial interventions to treat herniations in the human spine.
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Affiliation(s)
- Stephen R Sloan
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Christoph Wipplinger
- Department of Neurological Surgery, Weill Cornell Medical College, New York, NY 10065, USA
| | - Sertaç Kirnaz
- Department of Neurological Surgery, Weill Cornell Medical College, New York, NY 10065, USA
| | | | - Franziska Schmidt
- Department of Neurological Surgery, Weill Cornell Medical College, New York, NY 10065, USA
| | - Duncan McCloskey
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Tania Pannellini
- Pathology and Laboratory Medicine, Hospital for Special Surgery, New York, NY 10065, USA
| | | | - Roger Härtl
- Department of Neurological Surgery, Weill Cornell Medical College, New York, NY 10065, USA
| | - Lawrence J Bonassar
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA. .,Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA
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6
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Zheng K, Du D. Recent advances of hydrogel-based biomaterials for intervertebral disc tissue treatment: A literature review. J Tissue Eng Regen Med 2021; 15:299-321. [PMID: 33660950 DOI: 10.1002/term.3172] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 12/23/2020] [Indexed: 12/14/2022]
Abstract
Low back pain is an increasingly prevalent symptom mainly associated with intervertebral disc (IVD) degeneration. It is highly correlated with aging, as the nucleus pulposus (NP) dehydrates and annulus fibrosus fissure formatting, which finally results in the IVD herniation and related clinical symptoms. Hydrogels have been drawing increasing attention as the ideal candidates for IVD degeneration because of their unique properties such as biocompatibility, highly tunable mechanical properties, and especially the water absorption and retention ability resembling the normal NP tissue. Numerous innovative hydrogel polymers have been generated in the most recent years. This review article will first briefly describe the anatomy and pathophysiology of IVDs and current therapies with their limitations. Following that, the article introduces the hydrogel materials in the classification of their origins. Next, it reviews the recent hydrogel polymers explored for IVD regeneration and analyses what efforts have been made to overcome the existing limitations. Finally, the challenges and prospects of hydrogel-based treatments for IVD tissue are also discussed. We believe that these novel hydrogel-based strategies may shed light on new possibilities in IVD degeneration disease.
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Affiliation(s)
- Kaiwen Zheng
- Department of Orthopedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Dajiang Du
- Department of Orthopedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
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7
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Costi JJ, Ledet EH, O'Connell GD. Spine biomechanical testing methodologies: The controversy of consensus vs scientific evidence. JOR Spine 2021; 4:e1138. [PMID: 33778410 PMCID: PMC7984003 DOI: 10.1002/jsp2.1138] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/14/2022] Open
Abstract
Biomechanical testing methodologies for the spine have developed over the past 50 years. During that time, there have been several paradigm shifts with respect to techniques. These techniques evolved by incorporating state-of-the-art engineering principles, in vivo measurements, anatomical structure-function relationships, and the scientific method. Multiple parametric studies have focused on the effects that the experimental technique has on outcomes. As a result, testing methodologies have evolved, but there are no standard testing protocols, which makes the comparison of findings between experiments difficult and conclusions about in vivo performance challenging. In 2019, the international spine research community was surveyed to determine the consensus on spine biomechanical testing and if the consensus opinion was consistent with the scientific evidence. More than 80 responses to the survey were received. The findings of this survey confirmed that while some methods have been commonly adopted, not all are consistent with the scientific evidence. This review summarizes the scientific literature, the current consensus, and the authors' recommendations on best practices based on the compendium of available evidence.
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Affiliation(s)
- John J. Costi
- Biomechanics and Implants Research Group, Medical Device Research Institute, College of Science and EngineeringFlinders UniversityAdelaideAustralia
| | - Eric H. Ledet
- Department of Biomedical EngineeringRensselaer Polytechnic InstituteTroyNew YorkUSA
- Research and Development ServiceStratton VA Medical CenterAlbanyNew YorkUSA
| | - Grace D. O'Connell
- Department of Mechanical EngineeringUniversity of California‐BerkeleyBerkeleyCaliforniaUSA
- Department of Orthopaedic SurgeryUniversity of California‐San FranciscoSan FranciscoCaliforniaUSA
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8
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Gandhi SD, Maerz T, Mitchell S, Bachison C, Park DK, Fischgrund JS, Baker KC. Intradiscal Delivery of Anabolic Growth Factors and a Metalloproteinase Inhibitor in a Rabbit Acute Lumbar Disc Injury Model. Int J Spine Surg 2020; 14:585-593. [PMID: 32986582 DOI: 10.14444/7078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND The purpose of our study was to examine the effect of controlled delivery of TGF-β3, BMP-4, and TIMP-2 with a biocompatible biopolymer, chitosan, on an acutely injured intervertebral disc (IVD) in a rabbit model. METHODS After conducting an in vitro analysis of the chondrogenic capacity of the biomolecule cocktail use (ie, TGF-β3, BMP-4, and TIMP-2) and confirming stem cell viability in chitosan hydrogel, 15 New Zealand white rabbits underwent a lateral approach of the L1 to L4 IVDs. In each rabbit, the L2 to L3 IVD was left pristine, whereas the L1 to L2 and the L3 to L4 IVDs in each rabbit underwent nucleotomy via a 25-G needle, and the animal was subsequently randomized to no further treatment (defect only), chitosan alone, Chitosan + TGF-β3 + BMP-4, or chitosan + TGF-β3 + BMP-4 + TIMP-2. At 6 weeks after injury and intervention, the rabbits were killed and spines harvested to undergo quantitative T2 magnetic resonance imaging (MRI) and subsequent histologic analysis. RESULTS In the in vitro analysis, cells treated with experimental media containing TGF-β3, BMP-4, and TIMP-2 exhibited staining indicative of GAG production and began to exhibit a chondrocytic morphology. Quantitative T2 MRI mapping demonstrates that discs treated with chitosan, chitosan containing TGF-β3 and BMP-4, or chitosan containing TGF-β3, BMP-4, and TIMP-2 had consistently higher T2 relaxation times compared with defect-only discs. When the T2 relaxation times of each treatment group and defect-only discs were normalized to the healthy control disc, it was found that the T2 relaxation time of discs treated with chitosan containing TGF-β3 and BMP-4 and discs treated with chitosan containing TGF-β3, BMP-4, and TIMP-2 were significantly greater compared with defect-only discs (P = .048 and P = .013, respectively). Histologically, animals that received chitosan only, or chitosan with TGF-β3 and BMP-4, showed a significantly higher intensity of Safranin-O staining (P = .016 and P = .02, respectively) compared with control discs, whereas the difference in staining intensity in animals that received chitosan loaded with TGF-β3, BMP-4, and TIMP-2 failed to achieve significance (P = .161). CONCLUSIONS A combination of chitosan, TGF-β3, and BMP-4 was effective at promoting regeneration in an acute disc injury rabbit model, whereas TIMP-2 did not have a significant effect.
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Affiliation(s)
- Sapan D Gandhi
- Department of Orthopaedic Surgery, Beaumont Health System, Royal Oak, Michigan
| | - Tristan Maerz
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan
| | - Sean Mitchell
- Department of Orthopaedic Surgery, Beaumont Health System, Royal Oak, Michigan
| | - Casey Bachison
- Department of Orthopaedic Surgery, Beaumont Health System, Royal Oak, Michigan
| | - Daniel K Park
- Department of Orthopaedic Surgery, Beaumont Health System, Royal Oak, Michigan
| | | | - Kevin C Baker
- Department of Orthopaedic Surgery, Beaumont Health System, Royal Oak, Michigan
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9
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Sun B, Lian M, Han Y, Mo X, Jiang W, Qiao Z, Dai K. A 3D-Bioprinted dual growth factor-releasing intervertebral disc scaffold induces nucleus pulposus and annulus fibrosus reconstruction. Bioact Mater 2020; 6:179-190. [PMID: 32913927 PMCID: PMC7451922 DOI: 10.1016/j.bioactmat.2020.06.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 06/28/2020] [Accepted: 06/28/2020] [Indexed: 01/28/2023] Open
Abstract
Regeneration of Intervertebral disc (IVD) is a scientific challenge because of the complex structure and composition of tissue, as well as the difficulty in achieving bionic function. Here, an anatomically correct IVD scaffold composed of biomaterials, cells, and growth factors were fabricated via three-dimensional (3D) bioprinting technology. Connective tissue growth factor (CTGF) and transforming growth factor-β3 (TGF-β3) were loaded onto polydopamine nanoparticles, which were mixed with bone marrow mesenchymal stem cells (BMSCs) for regenerating and simulating the structure and function of the nucleus pulposus and annular fibrosus. In vitro experiments confirmed that CTGF and TGF-β3 could be released from the IVD scaffold in a spatially controlled manner, and induced the corresponding BMSCs to differentiate into nucleus pulposus like cells and annulus fibrosus like cells. Next, the fabricated IVD scaffold was implanted into the dorsum subcutaneous of nude mice. The reconstructed IVD exhibited a zone-specific matrix that displayed the corresponding histological and immunological phenotypes: primarily type II collagen and glycosaminoglycan in the core zone, and type I collagen in the surrounding zone. The testing results demonstrated that it exhibited good biomechanical function of the reconstructed IVD. The results presented herein reveal the clinical application potential of the dual growth factors-releasing IVD scaffold fabricated via 3D bioprinting. However, the evaluation in large mammal animal models needs to be further studied.
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Affiliation(s)
- Binbin Sun
- Department of Orthopaedic Surgery, Shanghai Key Laboratory of Orthopaedic Implants, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, China.,Clinical and Translational Research Center for 3D Printing Technology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
| | - Meifei Lian
- Department of Prosthodontics, Shanghai Ninth People's Hospital, College of Stomatology, Shanghai Jiao Tong University School of Medicine, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of Stomatology, Shanghai, 200011, China
| | - Yu Han
- Department of Orthopaedic Surgery, Shanghai Key Laboratory of Orthopaedic Implants, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, China.,Clinical and Translational Research Center for 3D Printing Technology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
| | - Xiumei Mo
- State Key Lab for Modification of Chemical Fibers & Polymer Materials, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai, 201620, China
| | - Wenbo Jiang
- Clinical and Translational Research Center for 3D Printing Technology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
| | - Zhiguang Qiao
- Department of Orthopaedic Surgery, Shanghai Key Laboratory of Orthopaedic Implants, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, China.,Clinical and Translational Research Center for 3D Printing Technology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China.,Department of Orthopaedic Surgery, Renji Hospital, South Campus, Shanghai Jiao Tong University School of Medicine, Shanghai, 201112, China
| | - Kerong Dai
- Department of Orthopaedic Surgery, Shanghai Key Laboratory of Orthopaedic Implants, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200080, China.,Clinical and Translational Research Center for 3D Printing Technology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200011, China
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10
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Zhang C, Gullbrand SE, Schaer TP, Boorman S, Elliott DM, Chen W, Dodge GR, Mauck RL, Malhotra NR, Smith LJ. Combined Hydrogel and Mesenchymal Stem Cell Therapy for Moderate-Severity Disc Degeneration in Goats. Tissue Eng Part A 2020; 27:117-128. [PMID: 32546053 DOI: 10.1089/ten.tea.2020.0103] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Intervertebral disc degeneration is a cascade of cellular, structural, and biomechanical changes that is strongly implicated as a cause of low-back pain. Current treatment strategies have poor long-term efficacy as they seek only to alleviate symptoms without preserving or restoring native tissue structure and function. The objective of this study was to evaluate the efficacy of a combined triple interpenetrating network hydrogel (comprising dextran, chitosan, and teleostean) and mesenchymal stem cell (MSC) therapy targeting moderate-severity disc degeneration in a clinically relevant goat model. Degeneration was induced in lumbar discs of 10 large frame goats by injection of chondroitinase ABC. After 12 weeks, degenerate discs were treated by injection of either hydrogel alone or hydrogel seeded with allogeneic, bone marrow-derived MSCs. Untreated healthy and degenerate discs served as controls, and animals were euthanized 2 weeks after treatment. Discs exhibited a significant loss of disc height 12 weeks after degeneration was induced. Two weeks after treatment, discs that received the combined hydrogel and MSC injection exhibited a significant, 10% improvement in disc height index, as well as improvements in histological condition. Discs that were treated with hydrogel alone exhibited reduced tumor necrosis factor-α expression in the nucleus pulposus (NP). Microcomputed tomography imaging revealed that the hydrogel remained localized to the central NP region of all treated discs after 2 weeks of unrestricted activity. These encouraging findings motivate further, longer term studies of therapeutic efficacy of hydrogel and MSC injections in this large animal model. Impact statement Low-back pain is the leading cause of disability worldwide, and degeneration of the intervertebral discs is considered to be one of the most common reasons for low-back pain. Current treatment strategies focus solely on alleviation of symptoms, and there is a critical need for new treatments that also restore disc structure and function. In this study, using a clinically relevant goat model of moderate-severity disc degeneration, we demonstrate that a combined interpenetrating network hydrogel and mesenchymal stem cell therapy provides acute improvements in disc height, histological condition, and local inflammation.
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Affiliation(s)
- Chenghao Zhang
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sarah E Gullbrand
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Thomas P Schaer
- Comparative Orthopaedic Research Laboratory, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA
| | - Sophie Boorman
- Comparative Orthopaedic Research Laboratory, New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA
| | - Dawn M Elliott
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, USA
| | - Weiliam Chen
- Department of Surgery, New York University School of Medicine, New York, New York, USA
| | - George R Dodge
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Robert L Mauck
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Neil R Malhotra
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Lachlan J Smith
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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11
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Virk S, Chen T, Meyers KN, Lafage V, Schwab F, Maher SA. Comparison of biomechanical studies of disc repair devices based on a systematic review. Spine J 2020; 20:1344-1355. [PMID: 32092506 PMCID: PMC9063717 DOI: 10.1016/j.spinee.2020.02.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 02/07/2020] [Accepted: 02/07/2020] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT A variety of solutions have been suggested as candidates for the repair of the annulus fibrosis (AF), with the ability to withstand physiological loads of paramount importance. PURPOSE The objective of our study was to capture the scope of biomechanical test models of AF repairs. We hypothesized that common test parameters would emerge. STUDY DESIGN Systematic Review METHODS: PubMed and EMBASE databases were searched for studies in English including the keywords "disc repair AND animal models," "disc repair AND cadaver spines," "intervertebral disc AND biomechanics," and "disc repair AND biomechanics." This list was further limited to those studies which included biomechanical results from annular repair in animal or human spinal segments from the cervical, thoracic, lumbar and/or coccygeal (tail) segments. For each study, the method used to measure the biomechanical property and biomechanical test results were documented. RESULTS A total of 2,607 articles were included within our initial analysis. Twenty-two articles met our inclusion criteria. Significant variability in terms of species tested, measurements used to quantify annular repair strength, and the method/direction/magnitude that forces were applied to a repaired annulus were found. Bovine intervertebral disc was most commonly used model (6 of 22 studies) and the most common mechanical property reported was the force required for failure of the disc repair device (15 tests). CONCLUSIONS Our hypothesis was rejected; no common features were identified across AF biomechanical models and as a result it was not possible to compare results of preclinical testing of annular repair devices. Our analysis suggests that a standardized biomechanical model that can be repeatably executed across multiple laboratories is required for the mechanical screening of candidates for AF repair. CLINICAL SIGNIFICANCE This literature review provides a summary of preclinical testing of annular repair devices for clinicians to properly evaluate the safety/efficacy of developing technology designed to repair annular defects after disc herniations.
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Affiliation(s)
- Sohrab Virk
- Hospital for Special Surgery, Department of Orthopedic Surgery, New York, New York,Orthopedic Soft Tissue Research Program, Hospital for Special Surgery, New York, NY
| | - Tony Chen
- Orthopedic Soft Tissue Research Program, Hospital for Special Surgery, New York, NY,Department of Biomechanics, Hospital for Special Surgery, New York, USA
| | | | - Virginie Lafage
- Hospital for Special Surgery, Department of Orthopedic Surgery, New York, New York
| | - Frank Schwab
- Hospital for Special Surgery, Department of Orthopedic Surgery, New York, New York
| | - Suzanne A. Maher
- Orthopedic Soft Tissue Research Program, Hospital for Special Surgery, New York, NY,Department of Biomechanics, Hospital for Special Surgery, New York, USA
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12
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Injectable cellulose-based hydrogels as nucleus pulposus replacements: Assessment of in vitro structural stability, ex vivo herniation risk, and in vivo biocompatibility. J Mech Behav Biomed Mater 2019; 96:204-213. [PMID: 31054515 DOI: 10.1016/j.jmbbm.2019.04.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 03/08/2019] [Accepted: 04/11/2019] [Indexed: 12/12/2022]
Abstract
Current treatments for intervertebral disc degeneration and herniation are palliative only and cannot restore disc structure and function. Nucleus pulposus (NP) replacements are a promising strategy for restoring disc biomechanics and height loss. Cellulose-based hydrogel systems offer potential for NP replacement since they are stable, non-toxic, may be tuned to match NP material properties, and are conducive to cell or drug delivery. A crosslinked, carboxymethylcellulose-methylcellulose dual-polymer hydrogel was recently formulated as an injectable NP replacement that gelled in situ and restored disc height and compressive biomechanical properties. The objective of this study was to investigate the translational potential of this hydrogel system by examining the long-term structural stability in vitro, the herniation risk and fatigue bending endurance in a bovine motion segment model, and the in vivo biocompatibility in a rat subcutaneous pouch model. Results showed that the hydrogels maintained their structural integrity over a 12-week period. AF injury significantly increased herniation risk and reduced fatigue bending endurance in bovine motion segments. Samples repaired with cellulosic hydrogels demonstrated restored height and exhibited herniation risk and fatigue endurance comparable to samples that underwent the current standard treatment of nucleotomy. Lastly, injected hydrogels elicited a minimal foreign body response as determined by analysis of fibrous capsule development and macrophage presence over 12 weeks. Overall, this injectable cellulosic hydrogel system is a promising candidate as an NP substitute. Further assessment and optimization of this cellulosic hydrogel system in an in vivo intradiscal injury model may lead to an improved clinical solution for disc degeneration and herniation.
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13
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Bhunia BK, Mandal BB. Exploring Gelation and Physicochemical Behavior of in Situ Bioresponsive Silk Hydrogels for Disc Degeneration Therapy. ACS Biomater Sci Eng 2018; 5:870-886. [DOI: 10.1021/acsbiomaterials.8b01099] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Bibhas K. Bhunia
- Biomaterial and Tissue Engineering Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781 039, India
| | - Biman B. Mandal
- Biomaterial and Tissue Engineering Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781 039, India
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14
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Varma DM, Lin HA, Long RG, Gold GT, Hecht AC, Iatridis JC, Nicoll SB. Thermoresponsive, redox-polymerized cellulosic hydrogels undergo in situ gelation and restore intervertebral disc biomechanics post discectomy. Eur Cell Mater 2018; 35:300-317. [PMID: 29845998 PMCID: PMC6016390 DOI: 10.22203/ecm.v035a21] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Back and neck pain are commonly associated with intervertebral disc (IVD) degeneration. Structural augmentation of diseased nucleus pulposus (NP) tissue with biomaterials could restore degeneration-related IVD height loss and degraded biomechanical behaviors; however, effective NP replacement biomaterials are not commercially available. This study developed a novel, crosslinked, dual-polymer network (DPN) hydrogel comprised of methacrylated carboxymethylcellulose (CMC) and methylcellulose (MC), and used in vitro, in situ and in vivo testing to assess its efficacy as an injectable, in situ gelling, biocompatible material that matches native NP properties and restores IVD biomechanical behaviors. Thermogelling MC was required to enable consistent and timely gelation of CMC in situ within whole IVDs. The CMC-MC hydrogel was tuned to match compressive and swelling NP tissue properties. When injected into whole IVDs after discectomy injury, CMC-MC restored IVD height and compressive biomechanical behaviors, including range of motion and neutral zone stiffness, to intact levels. Subcutaneous implantation of the hydrogels in rats further demonstrated good biocompatibility of CMC-MC with a relatively thin fibrous capsule, similar to comparable biomaterials. In conclusion, CMC-MC is an injectable, tunable and biocompatible hydrogel with strong potential to be used as an NP replacement biomaterial since it can gel in situ, match NP properties, and restore IVD height and biomechanical function. Future investigations will evaluate herniation risk under severe loading conditions and assess long-term in vivo performance.
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Affiliation(s)
| | | | | | | | | | | | - S B Nicoll
- Department of Biomedical Engineering, The City College of New York, Steinman Hall, Room 401, 160 Convent Avenue, New York, NY 10031,
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15
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Sikora SN, Miles DE, Tarsuslugil S, Mengoni M, Wilcox RK. Examination of an in vitro methodology to evaluate the biomechanical performance of nucleus augmentation in axial compression. Proc Inst Mech Eng H 2018; 232:230-240. [PMID: 29332499 PMCID: PMC5846852 DOI: 10.1177/0954411917752027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Intervertebral disc degeneration is one of the leading causes of back pain, but treatment options remain limited. Recently, there have been advances in the development of biomaterials for nucleus augmentation; however, the testing of such materials preclinically has proved challenging. The aim of this study was to develop methods for fabricating and testing bone-disc-bone specimens in vitro for examining the performance of nucleus augmentation procedures. Control, nucleotomy and treated intervertebral disc specimens were fabricated and tested under static load. The nucleus was removed from nucleotomy specimens using a trans-endplate approach with a bone plug used to restore bony integrity. Specimen-specific finite element models were developed to elucidate the reasons for the variations observed between control specimens. Although the computational models predicted a statistically significant difference between the healthy and nucleotomy groups, the differences found experimentally were not significantly different. This is likely due to variations in the material properties, hydration and level of annular collapse. The deformation of the bone was also found to be non-negligible. The study provides a framework for the development of testing protocols for nucleus augmentation materials and highlights the need to control disc hydration and the length of bone retained to reduce inter-specimen variability.
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Affiliation(s)
- Sebastien Nf Sikora
- 1 Institute of Medical and Biological Engineering, University of Leeds, Leeds, UK
| | - Danielle E Miles
- 1 Institute of Medical and Biological Engineering, University of Leeds, Leeds, UK.,2 School of Chemistry, University of Leeds, Leeds, UK
| | - Sami Tarsuslugil
- 1 Institute of Medical and Biological Engineering, University of Leeds, Leeds, UK
| | - Marlène Mengoni
- 1 Institute of Medical and Biological Engineering, University of Leeds, Leeds, UK
| | - Ruth K Wilcox
- 1 Institute of Medical and Biological Engineering, University of Leeds, Leeds, UK
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16
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Kumar D, Lyness A, Gerges I, Lenardi C, Forsyth NR, Liu Y. Stem Cell Delivery With Polymer Hydrogel for Treatment of Intervertebral Disc Degeneration: From 3D Culture to Design of the Delivery Device for Minimally Invasive Therapy. Cell Transplant 2016; 25:2213-2220. [PMID: 27452665 DOI: 10.3727/096368916x692618] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Nucleus pulposus (NP) tissue damage can induce detrimental mechanical strain on the biomechanical performance of intervertebral discs (IVDs), causing subsequent disc degeneration. A novel, photocurable, injectable, synthetic polymer hydrogel (pHEMA-co-APMA grafted with PAA) has already demonstrated success in encapsulating and differentiating human mesenchymal stem cells (hMSCs) toward an NP phenotype during hypoxic conditions. After demonstration of promising results in our previous work, in this study we have further investigated the inclusion of mechanical stimulation and its impact on hMSC differentiation toward an NP phenotype through the characterization of matrix markers such as SOX-9, aggrecan, and collagen II. Furthermore, investigations were undertaken in order to approximate delivery parameters for an injection delivery device, which could be used to transport hMSCs suspended in hydrogel into the IVD. hMSC-laden hydrogel solutions were injected through various needle gauge sizes in order to determine its impact on postinjection cell viability and IVD tissue penetration. Interpretation of these data informed the design of a potential minimally invasive injection device, which could successfully inject hMSCs encapsulated in a UV-curable polymer into NP, prior to photo-cross-linking in situ.
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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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Kinematic and fatigue biomechanics of an interpositional facet arthroplasty device. Spine J 2016; 16:531-9. [PMID: 26620944 DOI: 10.1016/j.spinee.2015.11.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 10/26/2015] [Accepted: 11/18/2015] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Although approximately 30% of chronic lumbar pain can be attributed to the facets, limited surgical options exist for patients. Interpositional facet arthroplasty (IFA) is a novel treatment for lumbar facetogenic pain designed to provide patients who gain insufficient relief from medical interventional treatment options with long-term relief, filling a void in the facet pain treatment continuum. PURPOSE This study aimed to quantify the effect of IFA on segmental range of motion (ROM) compared with the intact state, and to observe device position and condition after 10,000 cycles of worst-case loading. STUDY DESIGN/SETTING In situ biomechanical analysis of the lumbar spine following implantation of a novel IFA device was carried out. METHODS Twelve cadaveric functional spinal units (L2-L3 and L5-S1) were tested in 7.5 Nm flexion-extension, lateral bending, and torsion while intact and following device implantation. Additionally, specimens underwent 10,000 cycles of worst-case complex loading and were testing in ROM again. Load-displacement and fluoroscopic data were analyzed to determine ROM and to evaluate device position during cyclic testing. Devices and facets were evaluated post testing. Institutional support for implant evaluation was received by Zyga Technology. RESULTS Range of motion post implantation decreased versus intact, and then was restored post cyclic-testing. Of the tested devices, 6.5% displayed slight movement (0.5-2 mm), all from tight L2-L3 facet joints with misplaced devices or insufficient cartilage. No damage was observed on the devices, and wear patterns were primarily linear. CONCLUSIONS The results from this in situ cadaveric biomechanics and cyclic fatigue study demonstrate that a low-profile, conformable IFA device can maintain position and facet functionality post implantation and through 10,000 complex loading cycles. In vivo conditions were not accounted for in this model, which may affect implant behavior not predictable via a biomechanical study. However, these data along with published 1-year clinical results suggest that IFA may be a valid treatment option in patients with chronic lumbar zygapophysial pain who have exhausted medical interventional options.
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