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Evaluation of Topology Optimization Using 3D Printing for Bioresorbable Fusion Cages: A Biomechanical Study in a Porcine Model. Spine (Phila Pa 1976) 2023; 48:E46-E53. [PMID: 36130044 PMCID: PMC9855756 DOI: 10.1097/brs.0000000000004491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 08/31/2022] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Preclinical biomechanical study of topology optimization versus standard ring design for bioresorbable poly-ε-caprolactone (PCL) cervical spine fusion cages delivering bone morphogenetic protein-2 (BMP-2) using a porcine model. OBJECTIVE The aim was to evaluate range of motion (ROM) and bone fusion, as a function of topology optimization and BMP-2 delivery method. SUMMARY OF BACKGROUND DATA 3D printing technology enables fabrication of topology-optimized cages using bioresorbable materials, offering several advantages including customization, and lower stiffness. Delivery of BMP-2 using topology optimization may enhance the quality of fusion. METHODS Twenty-two 6-month-old pigs underwent anterior cervical discectomy fusion at one level using 3D printed PCL cages. Experimental groups (N=6 each) included: Group 1: ring design with surface adsorbed BMP-2, Group 2: topology-optimized rectangular design with surface adsorbed BMP-2, and Group 3: ring design with BMP-2 delivery via collagen sponge. Additional specimens, two of each design, were implanted without BMP-2, as controls. Complete cervical segments were harvested six months postoperatively. Nanocomputed tomography was performed to assess complete bony bridging. Pure moment biomechanical testing was conducted in all three planes, separately. Continuous 3D motions were recorded and analyzed. RESULTS Three subjects suffered early surgical complications and were not evaluated. Overall, ROM for experimental specimens, regardless of design or BMP-2 delivery method, was comparable, with no clinically significant differences among groups. Among experimental specimens at the level of the fusion, ROM was <1.0° in flexion and extension, indicative of fusion, based on clinically applied criteria for fusion of <2 to 4°. Despite the measured biomechanical stability, using computed tomography evaluation, complete bony bridging was observed in 40% of the specimens in Group 1, 50% of Group 2, 100% of Group 3, and none of the control specimens. CONCLUSION A topology-optimized PCL cage with BMP-2 is capable of resulting in an intervertebral fusion, similar to a conventional ring-based design of the same bioresorbable material.
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Zhang H, Wang Z, Wang Y, Li Z, Chao B, Liu S, Luo W, Jiao J, Wu M. Biomaterials for Interbody Fusion in Bone Tissue Engineering. Front Bioeng Biotechnol 2022; 10:900992. [PMID: 35656196 PMCID: PMC9152360 DOI: 10.3389/fbioe.2022.900992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 04/21/2022] [Indexed: 12/04/2022] Open
Abstract
In recent years, interbody fusion cages have played an important role in interbody fusion surgery for treating diseases like disc protrusion and spondylolisthesis. However, traditional cages cannot achieve satisfactory results due to their unreasonable design, poor material biocompatibility, and induced osteogenesis ability, limiting their application. There are currently 3 ways to improve the fusion effect, as follows. First, the interbody fusion cage is designed to facilitate bone ingrowth through the preliminary design. Second, choose interbody fusion cages made of different materials to meet the variable needs of interbody fusion. Finally, complete post-processing steps, such as coating the designed cage, to achieve a suitable osseointegration microstructure, and add other bioactive materials to achieve the most suitable biological microenvironment of bone tissue and improve the fusion effect. The focus of this review is on the design methods of interbody fusion cages, a comparison of the advantages and disadvantages of various materials, the influence of post-processing techniques and additional materials on interbody fusion, and the prospects for the future development of interbody fusion cages.
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Affiliation(s)
- Han Zhang
- Department of Orthopedics, The Second Hospital of Jilin University, Changchun, China
| | - Zhonghan Wang
- Department of Orthopedics, The Second Hospital of Jilin University, Changchun, China
- Orthopaedic Research Institute of Jilin Province, Changchun, China
| | - Yang Wang
- Department of Orthopedics, The Second Hospital of Jilin University, Changchun, China
| | - Zuhao Li
- Department of Orthopedics, The Second Hospital of Jilin University, Changchun, China
- Orthopaedic Research Institute of Jilin Province, Changchun, China
| | - Bo Chao
- Department of Orthopedics, The Second Hospital of Jilin University, Changchun, China
| | - Shixian Liu
- Department of Orthopedics, The Second Hospital of Jilin University, Changchun, China
| | - Wangwang Luo
- Department of Orthopedics, The Second Hospital of Jilin University, Changchun, China
| | - Jianhang Jiao
- Department of Orthopedics, The Second Hospital of Jilin University, Changchun, China
| | - Minfei Wu
- Department of Orthopedics, The Second Hospital of Jilin University, Changchun, China
- *Correspondence: Minfei Wu,
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Zhang NZ, Xiong QS, Yao J, Liu BL, Zhang M, Cheng CK. Biomechanical changes at the adjacent segments induced by a lordotic porous interbody fusion cage. Comput Biol Med 2022; 143:105320. [PMID: 35183971 DOI: 10.1016/j.compbiomed.2022.105320] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 02/11/2022] [Accepted: 02/11/2022] [Indexed: 12/12/2022]
Abstract
Biomechanical changes at the adjacent segments after interbody fusion are common instigators of adjacent segment degeneration (ASD). This study aims to investigate how the presence of a lordotic porous cage affects the biomechanical performance of the adjacent segments. A finite element model (FEM) of a lumbar spine implanted with a lordotic cage at L3-L4 was validated by in-vitro testing. The stress distribution on the cage and range of motion (ROM) of L3-L4 were used to assess the stability of the implant. Three angles of cage (0° = non-restoration, 7° = normal restoration and 11° = over-restoration) were modelled with different porosities (0%, 30% and 60%) and evaluated in the motions of flexion, extension, lateral bending and rotation. The ROM, intervertebral disc pressure (IDP) and facet joint force (FJF) were used to evaluate biomechanical changes at the adjacent segments in each model. The results indicated that porous cages produced more uniform stress distribution, but cage porosity did not influence the ROM, IDP and FJF at L2-L3 and L4-L5. Increasing the cage lordotic angle acted to decrease the ROM and IDP, and increase the FJF of L4-L5, but did not alter the ROM of L2-L3. In conclusion, changes in ROM, IDP and FJF at the adjacent segments were mainly influenced by the lordotic angle of the cage and not by the porosity. A larger angle of lordotic cage was shown to reduce the ROM and IDP, and increase the FJF of the lower segment (L4-L5), but had little effect on the ROM of the upper segment (L2-L3).
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Affiliation(s)
- Ning-Ze Zhang
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Qi-Sheng Xiong
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Jie Yao
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Bo-Lun Liu
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China
| | - Min Zhang
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China.
| | - Cheng-Kung Cheng
- Key Laboratory of Biomechanics and Mechanobiology, Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100083, China; School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200030, China.
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The advances of topology optimization techniques in orthopedic implants: A review. Med Biol Eng Comput 2021; 59:1673-1689. [PMID: 34363576 DOI: 10.1007/s11517-021-02361-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 04/05/2021] [Indexed: 10/20/2022]
Abstract
Metal implants are widely used in the treatment of orthopedic diseases. However, owing to the mismatched elastic modulus of the bone and implants, stress shielding often occurs clinically which can result in failure of the implant or fractures around the implant. Topology optimization (TO) is a technique that can provide more efficient material distribution according to the objective function under the special load and boundary conditions. Several researchers have paid close attention to TO for optimal design of orthopedic implants. Thanks to the development of additive manufacturing (AM), the complex structure of the TO design can be fabricated. This article mainly focuses on the current stage of TO technique with respect to the global layout and hierarchical structure in orthopedic implants. In each aspect, diverse implants in different orthopedic fields related to TO design are discussed. The characteristics of implants, methods of TO, validation methods of the newly designed implants, and limitations of current research have been summarized. The review concludes with future challenges and directions for research. Wang TO design of global layout and local structure of implants in diverse fields of orthopedic.
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Pharmaceutical electrospinning and 3D printing scaffold design for bone regeneration. Adv Drug Deliv Rev 2021; 174:504-534. [PMID: 33991588 DOI: 10.1016/j.addr.2021.05.007] [Citation(s) in RCA: 113] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 04/26/2021] [Accepted: 05/11/2021] [Indexed: 12/13/2022]
Abstract
Bone regenerative engineering provides a great platform for bone tissue regeneration covering cells, growth factors and other dynamic forces for fabricating scaffolds. Diversified biomaterials and their fabrication methods have emerged for fabricating patient specific bioactive scaffolds with controlled microstructures for bridging complex bone defects. The goal of this review is to summarize the points of scaffold design as well as applications for bone regeneration based on both electrospinning and 3D bioprinting. It first briefly introduces biological characteristics of bone regeneration and summarizes the applications of different types of material and the considerations for bone regeneration including polymers, ceramics, metals and composites. We then discuss electrospinning nanofibrous scaffold applied for the bone regenerative engineering with various properties, components and structures. Meanwhile, diverse design in the 3D bioprinting scaffolds for osteogenesis especially in the role of drug and bioactive factors delivery are assembled. Finally, we discuss challenges and future prospects in the development of electrospinning and 3D bioprinting for osteogenesis and prominent strategies and directions in future.
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Schleifenbaum S, Heilmann R, Riemer E, Reise R, Heyde CE, Jarvers JS, Pieroh P, Völker A, von der Hoeh NH. A Biomechanical Model for Testing Cage Subsidence in Spine Specimens with Osteopenia or Osteoporosis Under Permanent Maximum Load. World Neurosurg 2021; 152:e540-e548. [PMID: 34129990 DOI: 10.1016/j.wneu.2021.05.131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 05/31/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Intervertebral fusions in cases of reduced bone density are a tough challenge. From a biomechanical point of view, most current studies have focused on the range of motion or have shown test setups for single-component tests. Definitive setups for biomechanical testing of the primary stability of a 360° fusion using a screw-rod system and cage on osteoporotic spine are missing. The aim of this study was to develop a test stand to provide information about the bone-implant interface under reproducible conditions. METHODS After pretesting with artificial bone, functional spine units were tested with 360° fusion in the transforaminal lumbar interbody fusion technique. The movement sequences were conducted in flexion/extension, right and left lateral bending, and right and left axial rotation on a human model with osteopenia or osteoporosis under permanent maximum load with 7.5 N-m. RESULTS During the testing of human cadavers, 4 vertebrae were fully tested and were inconspicuous even after radiological and macroscopic examination. One vertebra showed a subsidence of 2 mm, and 1 vertebra had a cage collapsed into the vertebra. CONCLUSIONS This setup is suitable for biomechanical testing of cyclical continuous loads on the spine with reduced bone quality or osteoporosis. The embedding method is stable and ensures a purely single-level setup with different trajectories, especially when using the cortical bone trajectory. Optical monitoring provides a very accurate indication of cage movement, which correlates with the macroscopic and radiological results.
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Affiliation(s)
- Stefan Schleifenbaum
- Zentrum zur Erforschung der Stuetz- und Bewegungsorgane, University of Leipzig, Leipzig, Germany; Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Robin Heilmann
- Zentrum zur Erforschung der Stuetz- und Bewegungsorgane, University of Leipzig, Leipzig, Germany; Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Elena Riemer
- Zentrum zur Erforschung der Stuetz- und Bewegungsorgane, University of Leipzig, Leipzig, Germany; Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Rebekka Reise
- Zentrum zur Erforschung der Stuetz- und Bewegungsorgane, University of Leipzig, Leipzig, Germany; Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Christoph-Eckhard Heyde
- Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Jan-Sven Jarvers
- Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Philipp Pieroh
- Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Anna Völker
- Department of Orthopedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
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Porosity and pore design influence on fatigue behavior of 3D printed scaffolds for trabecular bone replacement. J Mech Behav Biomed Mater 2021; 117:104378. [PMID: 33610021 DOI: 10.1016/j.jmbbm.2021.104378] [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: 05/13/2020] [Revised: 12/29/2020] [Accepted: 02/01/2021] [Indexed: 12/22/2022]
Abstract
Polymeric scaffolds provide several advantages when compared with other bone replacement and regenerating techniques. Namely, when compared with the current gold standard, bone autografts, there is no shortage of supply nor donor site morbidity. Contrarily to metallic implants, their mechanical properties are similar to those of cortical bone and they are biodegradable, therefore stress shielding is not expected to occur, and they will be gradually replaced by new bone tissue. Yet, there are still several challenges to overcome. After implantation scaffolds are subjected to dynamic loads, thus understanding polymeric scaffolds' fatigue behavior plays a major role on the design of better products. In this work PLA scaffolds were manufactured using 3D printing with optimized parameters. A total of six configurations were tested under static and dynamic load conditions. Static compression testing and numerical simulation showed good correlation. Numerical simulation provided a viable resource for scaffold design and innovation. Four different low-cycle fatigue loads were applied, during 3600 cycles with a frequency of 0.25 Hz. While under dynamic conditions, with a maximum stress of 24 MPa and R = 0.1, the apparent compressive modulus reached 973 MPa, due to pore collapse. Even after 3600 cycles no significant fatigue damage mechanisms were found on low porosity scaffolds, rendering them useful for trabecular bone replacement under dynamic conditions.
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Chen H, Han Q, Wang C, Liu Y, Chen B, Wang J. Porous Scaffold Design for Additive Manufacturing in Orthopedics: A Review. Front Bioeng Biotechnol 2020; 8:609. [PMID: 32626698 PMCID: PMC7311579 DOI: 10.3389/fbioe.2020.00609] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/18/2020] [Indexed: 12/15/2022] Open
Abstract
With the increasing application of orthopedic scaffolds, a dramatically increasing number of requirements for scaffolds are precise. The porous structure has been a fundamental design in the bone tissue engineering or orthopedic clinics because of its low Young's modulus, high compressive strength, and abundant cell accommodation space. The porous structure manufactured by additive manufacturing (AM) technology has controllable pore size, pore shape, and porosity. The single unit can be designed and arrayed with AM, which brings controllable pore characteristics and mechanical properties. This paper presents the current status of porous designs in AM technology. The porous structures are stated from the cellular structure and the whole structure. In the aspect of the cellular structure, non-parametric design and parametric design are discussed here according to whether the algorithm generates the structure or not. The non-parametric design comprises the diamond, the body-centered cubic, and the polyhedral structure, etc. The Voronoi, the Triply Periodic Minimal Surface, and other parametric designs are mainly discussed in parametric design. In the discussion of cellular structures, we emphasize the design, and the resulting biomechanical and biological effects caused by designs. In the aspect of the whole structure, the recent experimental researches are reviewed on uniform design, layered gradient design, and layered gradient design based on topological optimization, etc. These parts are summarized because of the development of technology and the demand for mechanics or bone growth. Finally, the challenges faced by the porous designs and prospects of porous structure in orthopedics are proposed in this paper.
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Affiliation(s)
- Hao Chen
- Department of Orthopedics, Second Hospital of Jilin University, Changchun, China
| | - Qing Han
- Department of Orthopedics, Second Hospital of Jilin University, Changchun, China
| | - Chenyu Wang
- Department of Dermatology, The First Hospital of Jilin University, Changchun, China
| | - Yang Liu
- Department of Orthopedics, Second Hospital of Jilin University, Changchun, China
| | - Bingpeng Chen
- Department of Orthopedics, Second Hospital of Jilin University, Changchun, China
| | - Jincheng Wang
- Department of Orthopedics, Second Hospital of Jilin University, Changchun, China
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Tong Y, Kaplan DJ, Spivak JM, Bendo JA. Three-dimensional printing in spine surgery: a review of current applications. Spine J 2020; 20:833-846. [PMID: 31731009 DOI: 10.1016/j.spinee.2019.11.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/06/2019] [Accepted: 11/08/2019] [Indexed: 02/03/2023]
Abstract
In recent years, the use of three-dimensional printing (3DP) technology has gained traction in orthopedic spine surgery. Although research on this topic is still primarily limited to case reports and small cohort studies, it is evident that there are many avenues for 3DP innovation in the field. This review article aims to discuss the current and emerging 3DP applications in spine surgery, as well as the challenges of 3DP production and limitations in its use. 3DP models have been presented as helpful tools for patient education, medical training, and presurgical planning. Intraoperatively, 3DP devices may serve as patient-specific surgical guides and implants that improve surgical outcomes. However, the time, cost, and learning curve associated with constructing a 3DP model are major barriers to widespread use in spine surgery. Considering the costs and benefits of 3DP along with the varying risks associated with different spine procedures, 3DP technology is likely most valuable for complex or atypical spine disorder cases. Further research is warranted to gain a better understanding of how 3DP can and will impact spine surgery.
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Affiliation(s)
- Yixuan Tong
- New York University Grossman School of Medicine, 550 1st Ave, New York, NY 10016, USA
| | - Daniel James Kaplan
- Spine Division, New York University Langone Orthopedic Hospital, 301 E 17th St, New York, NY 10010, USA
| | - Jeffrey M Spivak
- Spine Division, New York University Langone Orthopedic Hospital, 301 E 17th St, New York, NY 10010, USA
| | - John A Bendo
- Spine Division, New York University Langone Orthopedic Hospital, 301 E 17th St, New York, NY 10010, USA.
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Aaron F, Clare M, Bastian B, Fredrick K, Tim D, Aurelien F. Dehydration-induced folding of poly(ε-caprolactone)-agarose hydrogel composites. Eur Polym J 2019. [DOI: 10.1016/j.eurpolymj.2019.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Gorbachuk VV, Padnya PL, Stoikov II. Synthesis of Macrocyclic Stereoisomers Substituted with Oligolactide Fragments. RUSS J GEN CHEM+ 2018. [DOI: 10.1134/s1070363218090128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Malikmammadov E, Tanir TE, Kiziltay A, Hasirci V, Hasirci N. PCL and PCL-based materials in biomedical applications. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2017; 29:863-893. [PMID: 29053081 DOI: 10.1080/09205063.2017.1394711] [Citation(s) in RCA: 372] [Impact Index Per Article: 53.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Biodegradable polymers have met with an increasing demand in medical usage over the last decades. One of such polymers is poly(ε-caprolactone) (PCL), which is a polyester that has been widely used in tissue engineering field for its availability, relatively inexpensive price and suitability for modification. Its chemical and biological properties, physicochemical state, degradability and mechanical strength can be adjusted, and therefore, it can be used under harsh mechanical, physical and chemical conditions without significant loss of its properties. Degradation time of PCL is quite long, thus it is used mainly in the replacement of hard tissues in the body where healing also takes an extended period of time. It is also used at load-bearing tissues of the body by enhancing its stiffness. However, due to its tailorability, use of PCL is not restricted to one type of tissue and it can be extended to engineering of soft tissues by decreasing its molecular weight and degradation time. This review outlines the basic properties of PCL, its composites, blends and copolymers. We report on various techniques for the production of different forms, and provide examples of medical applications such as tissue engineering and drug delivery systems covering the studies performed in the last decades.
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Affiliation(s)
- Elbay Malikmammadov
- a BIOMATEN, Center of Excellence in Biomaterials and Tissue Engineering , Middle East Technical University , Ankara , Turkey.,b Graduate Department of Micro and Nanotechnology, Graduate School of Natural and Applied Sciences , Middle East Technical University , Ankara , Turkey
| | - Tugba Endogan Tanir
- a BIOMATEN, Center of Excellence in Biomaterials and Tissue Engineering , Middle East Technical University , Ankara , Turkey.,c Central Laboratory , Middle East Technical University , Ankara , Turkey
| | - Aysel Kiziltay
- a BIOMATEN, Center of Excellence in Biomaterials and Tissue Engineering , Middle East Technical University , Ankara , Turkey.,c Central Laboratory , Middle East Technical University , Ankara , Turkey
| | - Vasif Hasirci
- a BIOMATEN, Center of Excellence in Biomaterials and Tissue Engineering , Middle East Technical University , Ankara , Turkey.,b Graduate Department of Micro and Nanotechnology, Graduate School of Natural and Applied Sciences , Middle East Technical University , Ankara , Turkey.,d Department of Biological Sciences , Middle East Technical University , Ankara , Turkey
| | - Nesrin Hasirci
- a BIOMATEN, Center of Excellence in Biomaterials and Tissue Engineering , Middle East Technical University , Ankara , Turkey.,b Graduate Department of Micro and Nanotechnology, Graduate School of Natural and Applied Sciences , Middle East Technical University , Ankara , Turkey.,e Department of Chemistry , Middle East Technical University , Ankara , Turkey
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Abstract
Spinal instrumentation often involves placing implants without direct visualization of their trajectory or proximity to adjacent neurovascular structures. Two-dimensional fluoroscopy is commonly used to navigate implant placement, but with the advent of computed tomography, followed by the invention of a mobile scanner with an open gantry, three-dimensional (3D) navigation is now widely used. This article critically appraises the available literature to assess the influence of 3D navigation on radiation exposure, accuracy of instrumentation, operative time, and patient outcomes. Also explored is the latest technological advance in 3D neuronavigation: the manufacturing of, via 3D printers, patient-specific templates that direct implant placement.
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Ling Q, He E, Ouyang H, Guo J, Yin Z, Huang W. Design of mulitlevel OLF approach ("V"-shaped decompressive laminoplasty) based on 3D printing technology. 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 2017; 27:323-329. [PMID: 28752243 DOI: 10.1007/s00586-017-5234-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/25/2017] [Accepted: 07/19/2017] [Indexed: 12/31/2022]
Abstract
PURPOSE To introduce a new surgical approach to the multilevel ossification of the ligamentum flavum (OLF) aided by three-dimensional (3D) printing technology. METHODS A multilevel OLF patient (male, 66 years) was scanned using computed tomography (CT). His saved DICOM format data were inputted to the Mimics14.0 3D reconstruction software (Materialise, Belgium). The resulting 3D model was used to observe the anatomical features of the multilevel OLF area and to design the surgical approach. At the base of the spinous process, two channels were created using an osteotomy bilaterally to create a "V" shape to remove the bone ligamentous complex (BLC). The decompressive laminoplasty using mini-plate fixation was simulated with the computer. The physical model was manufactured using 3D printing technology. The patient was subsequently treated using the designed surgery. RESULT The operation was completed successfully without any complications. The operative time was 90 min, and blood loss was 200 ml. One month after the operation, neurologic function was recovered well, and the JOA score was improved from 6 preoperatively to 10. Postoperative CT scanning showed that the OLF was totally removed, and the replanted BLC had not subsided. CONCLUSION 3D printing technology is an effective, reliable, and minimally invasive method to design operations. The technique can be an option for multilevel OLF surgical treatment. This can provide sufficient decompression with minimum damage to the spine and other intact anatomical structures.
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Affiliation(s)
- Qinjie Ling
- Institute of Clinical Anatomy, School of Basic Medical Sciences, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Erxing He
- Spinal Surgery, The First Affiliated Hospital of Guangzhou Medical University, 151 Yanjiang West Road, Guangzhou, 510120, China
| | - Hanbin Ouyang
- Institute of Clinical Anatomy, School of Basic Medical Sciences, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, China
| | - Jing Guo
- Spinal Surgery, The First Affiliated Hospital of Guangzhou Medical University, 151 Yanjiang West Road, Guangzhou, 510120, China
| | - Zhixun Yin
- Spinal Surgery, The First Affiliated Hospital of Guangzhou Medical University, 151 Yanjiang West Road, Guangzhou, 510120, China
| | - Wenhua Huang
- Institute of Clinical Anatomy, School of Basic Medical Sciences, Southern Medical University, 1838 Guangzhou Avenue North, Guangzhou, 510515, China.
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Miller AT, Safranski DL, Wood C, Guldberg RE, Gall K. Deformation and fatigue of tough 3D printed elastomer scaffolds processed by fused deposition modeling and continuous liquid interface production. J Mech Behav Biomed Mater 2017; 75:1-13. [PMID: 28689135 DOI: 10.1016/j.jmbbm.2017.06.038] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 06/27/2017] [Accepted: 06/30/2017] [Indexed: 12/16/2022]
Abstract
Polyurethane (PU) based elastomers continue to gain popularity in a variety of biomedical applications as compliant implant materials. In parallel, advancements in additive manufacturing continue to provide new opportunities for biomedical applications by enabling the creation of more complex architectures for tissue scaffolding and patient specific implants. The purpose of this study was to examine the effects of printed architecture on the monotonic and cyclic mechanical behavior of elastomeric PUs and to compare the structure-property relationship across two different printing approaches. We examined the tensile fatigue of notched specimens, 3D crosshatch scaffolds, and two 3D spherical pore architectures in a physically crosslinked polycarbonate urethane (PCU) printed via fused deposition modeling (FDM) as well as a photo-cured, chemically-crosslinked, elastomeric PU printed via continuous liquid interface production (CLIP). Both elastomers were relatively tolerant of 3D geometrical features as compared to stiffer synthetic implant materials such as PEEK and titanium. PCU and crosslinked PU samples with 3D porous structures demonstrated a reduced tensile failure stress as expected without a significant effect on tensile failure strain. PCU crosshatch samples demonstrated similar performance in strain-based tensile fatigue as solid controls; however, when plotted against stress amplitude and adjusted by porosity, it was clear that the architecture had an impact on performance. Square shaped notches or pores in crosslinked PU appeared to have a modest effect on strain-based tensile fatigue while circular shaped notches and pores had little impact relative to smooth samples. When plotted against stress amplitude, any differences in fatigue performance were small or not statistically significant for crosslinked PU samples. Despite the slight difference in local architecture and tolerances, crosslinked PU solid samples were found to perform on par with PCU solid samples in tensile fatigue, when appropriately adjusted for material hardness. Finally, tests of samples with printed architecture localized to the gage section revealed an effect in which fatigue performance appeared to drastically improve despite the localization of strain.
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Affiliation(s)
- Andrew T Miller
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA 30332, United States.
| | - David L Safranski
- MedShape, Inc., 1575 Northside Drive, NW, Suite 440, Atlanta, GA 30318, United States.
| | - Catherine Wood
- Department of Mechanical Engineering and Materials Science, Duke University, Box 90300 Hudson Hall, Durham, NC 27708, United States.
| | - Robert E Guldberg
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Drive, Atlanta, GA 30332, United States; George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801 Ferst Drive, Atlanta, GA 30332, United States.
| | - Ken Gall
- Department of Mechanical Engineering and Materials Science, Duke University, Box 90300 Hudson Hall, Durham, NC 27708, United States; MedShape, Inc., 1575 Northside Drive, NW, Suite 440, Atlanta, GA 30318, United States.
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Provaggi E, Leong JJH, Kalaskar DM. Applications of 3D printing in the management of severe spinal conditions. Proc Inst Mech Eng H 2016; 231:471-486. [PMID: 27658427 DOI: 10.1177/0954411916667761] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The latest and fastest-growing innovation in the medical field has been the advent of three-dimensional printing technologies, which have recently seen applications in the production of low-cost, patient-specific medical implants. While a wide range of three-dimensional printing systems has been explored in manufacturing anatomical models and devices for the medical setting, their applications are cutting-edge in the field of spinal surgery. This review aims to provide a comprehensive overview and classification of the current applications of three-dimensional printing technologies in spine care. Although three-dimensional printing technology has been widely used for the construction of patient-specific anatomical models of the spine and intraoperative guide templates to provide personalized surgical planning and increase pedicle screw placement accuracy, only few studies have been focused on the manufacturing of spinal implants. Therefore, three-dimensional printed custom-designed intervertebral fusion devices, artificial vertebral bodies and disc substitutes for total disc replacement, along with tissue engineering strategies focused on scaffold constructs for bone and cartilage regeneration, represent a set of promising applications towards the trend of individualized patient care.
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Affiliation(s)
- Elena Provaggi
- 1 Centre for Nanotechnology & Tissue Engineering, Division of Surgery and Interventional Science, UCL Medical School, University College London, London, UK
| | - Julian J H Leong
- 1 Centre for Nanotechnology & Tissue Engineering, Division of Surgery and Interventional Science, UCL Medical School, University College London, London, UK.,2 Royal National Orthopaedic Hospital, Stanmore, UK
| | - Deepak M Kalaskar
- 1 Centre for Nanotechnology & Tissue Engineering, Division of Surgery and Interventional Science, UCL Medical School, University College London, London, UK
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