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Losch MS, Kardux F, Dankelman J, Hendriks BHW. Diffuse reflectance spectroscopy of the spine: improved breach detection with angulated fibers. BIOMEDICAL OPTICS EXPRESS 2023; 14:739-750. [PMID: 36874502 PMCID: PMC9979673 DOI: 10.1364/boe.471725] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 12/07/2022] [Accepted: 12/14/2022] [Indexed: 06/18/2023]
Abstract
Accuracy in spinal fusion varies greatly depending on the experience of the physician. Real-time tissue feedback with diffuse reflectance spectroscopy has been shown to provide cortical breach detection using a conventional probe with two parallel fibers. In this study, Monte Carlo simulations and optical phantom experiments were conducted to investigate how angulation of the emitting fiber affects the probed volume to allow for the detection of acute breaches. Difference in intensity magnitude between cancellous and cortical spectra increased with the fiber angle, suggesting that outward angulated fibers are beneficial in acute breach scenarios. Proximity to the cortical bone could be detected best with fibers angulated at θ f = 45 ∘ for impending breaches between θ p = 0 ∘ and θ p = 45 ∘ . An orthopedic surgical device comprising a third fiber perpendicular to the device axis could thus cover the full impending breach range from θ p = 0 ∘ to θ p = 90 ∘ .
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Affiliation(s)
- Merle S. Losch
- Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands
| | - Famke Kardux
- Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands
| | - Jenny Dankelman
- Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands
| | - Benno H. W. Hendriks
- Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands
- Image Guided Therapy and Ultrasound Devices
and System Department, Philips Research,
Royal Philips NV, Eindhoven, The
Netherlands
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2
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Chen C, Huang Y, Chen P, Hsu Y, Jaw F, Ho M. Modification of gelatin and photocured
3D
‐printed resin to prepare biomimetic phantoms for ultrasound‐guided minimally invasive surgeries. POLYM ENG SCI 2023. [DOI: 10.1002/pen.26216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Chien‐Hua Chen
- Department of Biomedical Engineering National Taiwan University Taipei City Taiwan
| | - Yi‐Fan Huang
- Department of Chemical Engineering National Taiwan University of Science and Technology Taipei City Taiwan
| | - Po‐Hao Chen
- Department of Chemical Engineering National Taiwan University of Science and Technology Taipei City Taiwan
| | - Yu‐Tung Hsu
- Department of Chemical Engineering National Taiwan University of Science and Technology Taipei City Taiwan
| | - Fu‐Shan Jaw
- Department of Biomedical Engineering National Taiwan University Taipei City Taiwan
| | - Ming‐Hua Ho
- Department of Chemical Engineering National Taiwan University of Science and Technology Taipei City Taiwan
- R&D Center for Membrane Technology National Taiwan University of Science and Technology Taipei Taiwan
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3
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Liu L, Zhao Y, Li A, Yu X, Xiao X, Liu S, Meng MQH. A photoacoustics-enhanced drilling probe for radiation-free pedicle screw implantation in spinal surgery. Front Bioeng Biotechnol 2022; 10:1000950. [PMID: 36185423 PMCID: PMC9520603 DOI: 10.3389/fbioe.2022.1000950] [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: 07/22/2022] [Accepted: 08/15/2022] [Indexed: 12/02/2022] Open
Abstract
This article proposes a novel intra-operative navigation and sensing system that optimizes the functional accuracy of spinal pedicle screw implantation. It does so by incorporating radiation-free and multi-scale macroscopic 3D ultrasound (US) imaging and local tissue-awareness from in situ photoacoustic (PA) sensing at a clinically relevant mesoscopic scale. More specifically, 3D US imaging is employed for online status updates of spinal segment posture to determine the appropriate entry point and coarse drilling path once non-negligible or relative patient motion occurs between inter-vertebral segments in the intra-operative phase. Furthermore, a sophisticated sensor-enhanced drilling probe has been developed to facilitate fine-grained local navigation that integrates a PA endoscopic imaging component for in situ tissue sensing. The PA signals from a sideways direction to differentiate cancellous bone from harder cortical bone, or to indicate weakened osteoporotic bone within the vertebrae. In so doing it prevents cortical breaches, strengthens implant stability, and mitigates iatrogenic injuries of the neighboring artery and nerves. To optimize this PA-enhanced endoscopic probe design, the light absorption spectrum of cortical bone and cancellous bone are measured in vitro, and the associated PA signals are characterized. Ultimately, a pilot study is performed on an ex vivo bovine spine to validate our developed multi-scale navigation and sensing system. The experimental results demonstrate the clinical feasibility, and hence the great potential, for functionally accurate screw implantation in complex spinal stabilization interventions.
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Affiliation(s)
- Li Liu
- Department of Electronic Engineering, The Chinese University of Hong Kong, Hong Kong SAR, China
- *Correspondence: Li Liu, ; Siyu Liu,
| | - Yongjian Zhao
- Department of Electronic Engineering, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Ang Li
- Department of Electronic Engineering, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Xianghu Yu
- Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Xiao Xiao
- Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Siyu Liu
- School of Science, Nanjing University of Science and Technology, Nanjing, China
- *Correspondence: Li Liu, ; Siyu Liu,
| | - Max Q.-H. Meng
- Department of Electronic Engineering, The Chinese University of Hong Kong, Hong Kong SAR, China
- Department of Electronic and Electrical Engineering, Southern University of Science and Technology, Shenzhen, China
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4
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Chan A, Parent E, Mahood J, Lou E. 3D ultrasound navigation system for screw insertion in posterior spine surgery: a phantom study. Int J Comput Assist Radiol Surg 2021; 17:271-281. [PMID: 34725774 DOI: 10.1007/s11548-021-02516-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 09/29/2021] [Indexed: 10/19/2022]
Abstract
PURPOSE Posterior spinal fusion surgery is required to correct severe idiopathic scoliosis. The surgery involves insertion of screws which requires high accuracy to prevent neurologic damage to the spinal cord. Although conventional CT navigation can reduce this risk, 3D-ultrasound-based navigation could achieve this without added ionizing radiation and usage of expensive and bulky equipment. This study aimed to evaluate the accuracy of a 3D ultrasound navigation system for posterior spine surgery. METHODS A custom 3D ultrasound (3DUS) with model-to-surface registration algorithm was developed and integrated into a 3D navigation environment. A CT scan of an adolescent spine (T3-T11) was segmented and 3D printed for experiments. A probe with reflective markers was placed in vertebral pedicles 684 times in varying levels, positions in the capture space and orientation of vertebra, and the entrypoint and trajectory accuracies were measured. RESULTS Among 684 probe placements in vertebral levels T3 to T11 in the phantom spine, 95.5% were within 1 mm and 5° of accuracy, with an average accuracy of 0.4 ± 0.4 mm and 2.1 ± 0.9°, requiring 8.8 s to process. Accuracies were statistically significantly affected by vertebral orientation and position in the capture volume, though this was still within the targeted accuracies of 1 mm and 5°. CONCLUSION This preliminary ultrasound-based navigation system is accurate and fast enough for guiding placement of pedicle screws into the spine in posterior fusion surgery. The current results are limited to phantom spines, and future study in animal or human cadavers is needed to investigate soft tissue effects on registration accuracy.
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Affiliation(s)
- Andrew Chan
- Department of Biomedical Engineering, University of Alberta, 1098 Research Transition Facility, 8308-114 Street, Edmonton, AB, T6G 2V2, Canada
| | - Eric Parent
- Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, 2-50 Corbett Hall, Edmonton, AB, T6G2G4, Canada
| | - Jim Mahood
- Department of Surgery, University of Alberta, 2D, Walter C Mackenzie Health Sciences Center - 8440 - 112 Street, Edmonton, AB, T6G 2B7, Canada
| | - Edmond Lou
- Department of Biomedical Engineering, University of Alberta, 1098 Research Transition Facility, 8308-114 Street, Edmonton, AB, T6G 2V2, Canada.
- Department of Surgery, University of Alberta, 2D, Walter C Mackenzie Health Sciences Center - 8440 - 112 Street, Edmonton, AB, T6G 2B7, Canada.
- Department of Electrical Engineering, University of Alberta, Donadeo ICE 11-263, 9211-116 Street, Edmonton, AB, T6G 1H9, Canada.
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Chan A, Coutts B, Parent E, Lou E. Development and Evaluation of CT-to-3D Ultrasound Image Registration Algorithm in Vertebral Phantoms for Spine Surgery. Ann Biomed Eng 2020; 49:310-321. [PMID: 32533392 DOI: 10.1007/s10439-020-02546-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 06/04/2020] [Indexed: 12/18/2022]
Abstract
Posterior spinal fusion surgery requires careful insertion of screws into the spine to avoid neurologic injury. While current systems use CT-scans, three-dimensional ultrasound (3DUS) could provide guidance by reconstructing the vertebral surface, and then registering a pre-operative vertebral model to that surface for localization. The aim of this study was to evaluate the accuracy and processing time of a custom CT-3DUS registration algorithm. A phantom human vertebra was 3D-printed and scanned with a motion capture-based 3D ultrasound (3DUS) system. Image registration was performed that included a pre-alignment phase using vertebral symmetry information, and then comparing Gaussian pyramid intensity-based registration with iterative-closest-point registration for final transformations. Image registration was performed 192 times while surgical registration between CT and real-world position was performed 84 times. The accuracy of image registration (CT-to-3DUS) was 0.3 ± 0.2 mm and 0.9 ± 0.8° completed in 13.3 ± 2.9 s. The surgical navigation accuracy (CT model to real-world position) of the system was 1.2 ± 0.5 mm and 2.2 ± 2.0° completed in 16.2 ± 3.0 s. Both meet accuracy thresholds of < 2 mm and < 5° required for the surgery. A feasibility study on porcine spine qualitatively showed appropriate overlapping anatomy in CT-3DUS registrations. The usage of 3D ultrasound for navigation has demonstrated accuracy to provide radiation-free image guidance for spine surgery.
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Affiliation(s)
- Andrew Chan
- Department of Biomedical Engineering, University of Alberta, 1098 Research Transition Facility, 8308-114 Street, Edmonton, AB, T6G 2V2, Canada
| | - Brendan Coutts
- Department of Electrical and Computer Engineering, University of Alberta, Donadeo ICE 11-203, 9211-116 Street, Edmonton, AB, T6G 1H9, Canada
| | - Eric Parent
- Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, 2-50 Corbett Hall, Edmonton, AB, T6G2G4, Canada
| | - Edmond Lou
- Department of Biomedical Engineering, University of Alberta, 1098 Research Transition Facility, 8308-114 Street, Edmonton, AB, T6G 2V2, Canada. .,Department of Electrical and Computer Engineering, University of Alberta, Donadeo ICE 11-203, 9211-116 Street, Edmonton, AB, T6G 1H9, Canada.
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6
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Chan A, Parent E, Lou E. Reconstruction and positional accuracy of 3D ultrasound on vertebral phantoms for adolescent idiopathic scoliosis spinal surgery. Int J Comput Assist Radiol Surg 2018; 14:427-439. [PMID: 30519871 DOI: 10.1007/s11548-018-1894-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 11/28/2018] [Indexed: 10/27/2022]
Abstract
PURPOSE Determine the positional, rotational and reconstruction accuracy of a 3D ultrasound system to be used for image registration in navigation surgery. METHODS A custom 3D ultrasound for spinal surgery image registration was developed using Optitrack Prime 13-W motion capture cameras and a SonixTablet Ultrasound System. Temporal and spatial calibration was completed to account for time latencies between the two systems and to ensure accurate motion tracking of the ultrasound transducer. A mock operating room capture volume with a pegboard grid was set up to allow phantoms to be placed at a variety of predetermined positions to validate accuracy measurements. Five custom-designed ultrasound phantoms were 3D printed to allow for a range of linear and angular dimensions to be measured when placed on the pegboard. RESULTS Temporal and spatial calibration was completed with measurement repeatabilities of 0.2 mm and 0.5° after calibration. The mean positional accuracy was within 0.4 mm, with all values within 0.5 mm within the critical surgical regions and 96% of values within 1 mm within the full capture volume. All orientation values were within 1.5°. Reconstruction accuracy was within 0.6 mm and 0.9° for geometrically shaped phantoms and 0.5 and 1.9° for vertebrae-mimicking phantoms. CONCLUSIONS The accuracy of the developed 3D ultrasound system meets the 1 mm and 5° requirements of spinal surgery from this study. Further repeatability studies and evaluation on vertebrae are needed to validate the system for surgical use.
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Affiliation(s)
- Andrew Chan
- Department of Biomedical Engineering, University of Alberta, 1098 Research Transition Facility, 8308-114 Street, Edmonton, AB, T6G 2V2, Canada
| | - Eric Parent
- Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, 2-50 Corbett Hall, Edmonton, AB, T6G2G4, Canada
| | - Edmond Lou
- Department of Biomedical Engineering, University of Alberta, 1098 Research Transition Facility, 8308-114 Street, Edmonton, AB, T6G 2V2, Canada. .,Department of Electrical and Computer Engineering, University of Alberta, Donadeo ICE 11-371, 9211-116 Street, Edmonton, AB, T6G 1H9, Canada.
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7
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Chen Z, Wu B, Zhai X, Bai Y, Zhu X, Luo B, Chen X, Li C, Yang M, Xu K, Liu C, Wang C, Zhao Y, Wei X, Chen K, Yang W, Ta D, Li M. Basic study for ultrasound-based navigation for pedicle screw insertion using transmission and backscattered methods. PLoS One 2015; 10:e0122392. [PMID: 25861053 PMCID: PMC4393101 DOI: 10.1371/journal.pone.0122392] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Accepted: 02/21/2015] [Indexed: 12/04/2022] Open
Abstract
The purpose of this study was to understand the acoustic properties of human vertebral cancellous bone and to study the feasibility of ultrasound-based navigation for posterior pedicle screw fixation in spinal fusion surgery. Fourteen human vertebral specimens were disarticulated from seven un-embalmed cadavers (four males, three females, 73.14 ± 9.87 years, two specimens from each cadaver). Seven specimens were used to measure the transmission, including tests of attenuation and phase velocity, while the other seven specimens were used for backscattered measurements to inspect the depth of penetration and A-Mode signals. Five pairs of unfocused broadband ultrasonic transducers were used for the detection, with center frequencies of 0.5 MHz, 1 MHz, 1.5 MHz, 2.25 MHz, and 3.5 MHz. As a result, good and stable results were documented. With increased frequency, the attenuation increased (P<0.05), stability of the speed of sound improved (P<0.05), and penetration distance decreased (P>0.05). At about 0.6 cm away from the cortical bone, warning signals were easily observed from the backscattered measurements. In conclusion, the ultrasonic system proved to be an effective, moveable, and real-time imaging navigation system. However, how ultrasonic navigation will benefit pedicle screw insertion in spinal surgery needs to be determined. Therefore, ultrasound-guided pedicle screw implantation is theoretically effective and promising.
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Affiliation(s)
- Ziqiang Chen
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Bing Wu
- Department of Orthopedics, 401st Hospital Center, Qingdao, Shandong Province, PR China
| | - Xiao Zhai
- Graduate Management Unit, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Yushu Bai
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Xiaodong Zhu
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Beier Luo
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Xiao Chen
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Chao Li
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Mingyuan Yang
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Kailiang Xu
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Chengcheng Liu
- Department of Electronic Engineering, Fudan University, Shanghai, PR China
| | - Chuanfeng Wang
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Yingchuan Zhao
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Xianzhao Wei
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Kai Chen
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Wu Yang
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
| | - Dean Ta
- Department of Electronic Engineering, Fudan University, Shanghai, PR China
- * E-mail: (ML); (DT)
| | - Ming Li
- Department of Orthopedics, Changhai hospital affiliated to the Second Military Medical University, Shanghai, PR China
- * E-mail: (ML); (DT)
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Gdyczynski CM, Manbachi A, Hashemi S, Lashkari B, Cobbold RSC. On estimating the directionality distribution in pedicle trabecular bone from micro-CT images. Physiol Meas 2014; 35:2415-28. [PMID: 25391037 DOI: 10.1088/0967-3334/35/12/2415] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Our interest in the trabecular alignment within bone stems from the need to better understand the manner in which it can affect ultrasound propagation, particularly in pedicles. Within long bones it is well established that trabecular structures are aligned in an organized manner associated with the direction of load distribution; however, for smaller bones there are limited alignment studies. To investigate the directionality distribution in a quantitative manner we used a micro-CT to obtain three-dimensional (3D) structural data and developed analytical methods based on the special properties of Gabor filters. Implementation of these techniques has been developed and tested on a variety of simulated images as well as on 3D structures whose geometry is well-defined. To test the use of this technique we compared the results obtained on vertebral body trabecular bone with visual directionality and previous measurements by others. The method has been applied to six human pedicle samples in two orthogonal planes with results that provide reasonable proof-of-principle evidence that the method is well suited for estimating the directionality distribution within pedicle bones.
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Affiliation(s)
- Catherine M Gdyczynski
- Institute of Biomaterials and Biomedical Engineering (IBBME), University of Toronto, M5S 3G9, Toronto, Canada. Spinesonics Medical Inc, 411-112 College St, M5G 1L6, Toronto, Ontario, Canada
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9
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Manbachi A, Cobbold RSC, Ginsberg HJ. Guided pedicle screw insertion: techniques and training. Spine J 2014; 14:165-79. [PMID: 23623511 DOI: 10.1016/j.spinee.2013.03.029] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 10/25/2012] [Accepted: 03/07/2013] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT In spinal fusion surgery, the accuracy with which screws are inserted in the pedicle has a direct effect on the surgical outcome. Accurate placement generally involves considerable judgmental skills that have been developed through a lengthy training process. Because the impact of misaligning one or more pedicle screws can directly affect patient safety, a number of navigational and trajectory verification approaches have been described and evaluated in the literature to provide some degree of guidance to the surgeon. PURPOSE To provide a concise review to justify the need and explore the current state of developing navigational or trajectory verification techniques for ensuring proper pedicle screw insertion along with simulation methods for better educating the surgical trainees. STUDY DESIGN Recent literature review. METHODS To justify the need to develop new methods for optimizing pedicle screw paths, we first reviewed some of the recent publications relating to the statistical outcomes for different types of navigation along with the conventional freehand (unassisted) screw insertion. Second, because of the importance of providing improved training in the skill of accurate screw insertion, the training aspects of relevant techniques are considered. The third part is devoted to the description of specific navigational assist methods or trajectory verification techniques and these include computer-assisted navigation, three-dimensional simulations, and also electric impedance and optical and ultrasonic image-guided methods. CONCLUSIONS This article presents an overview of the need and the current status of the guidance methods available for improving the surgical outcomes in spinal fusion procedures. It also describes educational aids that have the potential for reducing the training process.
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Affiliation(s)
- Amir Manbachi
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College St, Toronto, Ontario, Canada M5S 3G9
| | - Richard S C Cobbold
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College St, Toronto, Ontario, Canada M5S 3G9.
| | - Howard J Ginsberg
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College St, Toronto, Ontario, Canada M5S 3G9; Division of Neurosurgery, St Michael's Hospital, 30 Bond Street, Toronto, Ontario, Canada M5B 1W8
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10
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Yamada M, Moriya H, Iino T, Kasai Y, Sudo A, Uchida A. Ultrasonic measurement of bone thickness for spinal surgery. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2012; 59:2077-2088. [PMID: 23007783 DOI: 10.1109/tuffc.2012.2429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We measured the thickness of the transverse structures associated with the bovine coccygeal transverse processes (bone specimen) by using ultrasonic waves and examined the reliability of this measurement for use in spinal surgery. We first measured the velocity of ultrasonic waves propagating in the spinous process. We then made a hole in the transverse process with an air drill and placed an ultrasonic transducer with a center frequency of 10 MHz in the hole. The time of reflection of the ultrasonic wave from the underside of the transverse process was detected to estimate the remaining bone thickness. The thickness estimated by using ultrasound was compared with the thickness measured by microscopic examination. We could detect reflection waves from the underside of the transverse process in 91.7% of cases (i.e., 22 of 24 measurements using 6 bones from 3 cows). The thickness of the transverse processes in which we detected the waves varied from 0.24 to 6.8 mm. The 95% limit of agreement between ultrasonic and histological measurement was 0.71 mm. Pearson's correlation coefficient showed a strong and positive relationship between the two measurements (r = 0.97, n = 22, P <0.0001).
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11
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Zhang C, Le LH, Zheng R, Ta D, Lou E. Measurements of ultrasonic phase velocities and attenuation of slow waves in cellular aluminum foams as cancellous bone-mimicking phantoms. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2011; 129:3317-26. [PMID: 21568432 DOI: 10.1121/1.3562560] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The water-saturated aluminum foams with an open network of interconnected ligaments were investigated by ultrasonic transmission technique for the suitability as cancellous bone-mimicking phantoms. The phase velocities and attenuation of nine samples covering three pores per inch (5, 10, and 20 PPI) and three aluminum volume fractions (5, 8, and 12% AVF) were measured over a frequency range of 0.7-1.3 MHz. The ligament thickness and pore sizes of the phantoms and low-density human cancellous bones are similar. A strong slow wave and a weak fast wave are observed for all samples while the latter is not visible without significant amplification (100x). This study reports the characteristics of slow wave, whose speeds are less than the sound speed of the saturating water and decrease mildly with AVF and PPI with an average 1469 m/s. Seven out of nine samples show positive dispersion and the rest show minor negative dispersion. Attenuation increases with AVF, PPI, and frequency except for the 20 PPI samples, which exhibit non-increasing attenuation level with fluctuations due to scattering. The phase velocities agree with Biot's porous medium theory. The RMSE is 16.0 m/s (1%) at n = 1.5. Below and above this value, the RMSE decreases mildly and rises sharply, respectively.
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Affiliation(s)
- Chan Zhang
- Department of Radiology and Diagnostic Imaging, University of Alberta, Edmonton, Alberta T6G 2B7, Canada
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12
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Chang JH, Raphael DT, Zhang YP, Shung KK. Proof of concept: In vitro measurement of correlation between radiodensity and ultrasound echo response of ovine vertebral bodies. ULTRASONICS 2011; 51:253-257. [PMID: 21112601 PMCID: PMC3022323 DOI: 10.1016/j.ultras.2010.10.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 10/26/2010] [Accepted: 10/28/2010] [Indexed: 05/30/2023]
Abstract
An acoustic guidance method for pedicle screw placement during spine fixation surgery was recently investigated, with a view toward preventing complications such as injury to the spinal cord, thecal sac, and spinal nerve roots due to screw misplacement. The method relies upon the change in the ultrasound amplitude reflected at different sites-from the outer posterior cortex, through the pedicle, and towards the distal ventral cortex. The amplitude change was empirically observed through in vitro measurement of ultrasound amplitude at the different sites by inserting a 2.5-MHz single element transducer into a vertebral body through insertion pathway created by an advancing screw. This paper provides a theoretical and experimental rationale behind these empirical findings and distance-dependent correlation coefficients between amplitude and bone mineral density within the vertebral body, which approached 97%.
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Affiliation(s)
- Jin Ho Chang
- Sogang Institute of Advanced Technology, Sogang University, Seoul, Republic of Korea.
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13
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Aly AH, Ginsberg HJ, Cobbold RSC. On ultrasound imaging for guided screw insertion in spinal fusion surgery. ULTRASOUND IN MEDICINE & BIOLOGY 2011; 37:651-664. [PMID: 21376451 DOI: 10.1016/j.ultrasmedbio.2011.01.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Revised: 01/10/2011] [Accepted: 01/14/2011] [Indexed: 05/30/2023]
Abstract
Spinal fusion surgery generally involves the insertion of screws in the pedicle, a three-dimensional (3-D) process that requires great skill if serious consequences are to be avoided. This article describes an image guidance technique based on generating B‑mode images from within a small bore hole in the pedicle's trabecular bone. The purpose is to determine the viability and safety of the hole placement for subsequent insertion of the screw. Toward this end, this article endeavours to understand the factors that govern B-mode image quality. Specifically, the results of numerical simulations on the effects of transducer frequency and bone volume on image quality are presented along with demonstrations of B-mode image formation obtained in vitro on human pedicles using a 3.2 MHz probe. The results of the numerical simulations suggest that high frequency and high bone volume generally reduce the image quality. The in vitro experiments showed that the trabecular and cortical bone can be detected in the B-mode images.
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Affiliation(s)
- Al-Hassan Aly
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
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14
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Raphael DT, Chang JH, Zhang YP, Kudija D, Chen TC, Shung KK. A-Mode ultrasound guidance for pedicle screw advancement in ovine vertebral bodies. Spine J 2010; 10:422-32. [PMID: 20347399 PMCID: PMC2860664 DOI: 10.1016/j.spinee.2010.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Revised: 12/22/2009] [Accepted: 02/05/2010] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT In pedicle screw fixation surgery, rigid instruments are inserted into a vertebral body. When the instruments are misdirected within the pedicle or advanced too far beyond it, perforations of the inner or outer cortex can cause damage to the spinal nerve roots and spinal cord. These complications can occur despite the use of imaging modalities, such as radiographs, fluoroscopy, and computerized axial tomography (CAT) scans. A-Mode ultrasound (US), a nonionizing modality, merits study for its possible use in such a type of surgery. PURPOSE The purpose of the study was to determine the utility of A-mode US during pedicle screw placement, to characterize the approach to the marrow-cortex interface, and to obtain the signature profiles of cortex perforations. STUDY DESIGN A-Mode data were generated on insertion of a forward-viewing transducer (FVT) and a side-viewing transducer (SVT) to successively greater drilled depths along the insertion pathway. A-Mode broadband US backscatter (BUB) pedicle screw emulation experiments were conducted with transducers inserted into drilled sheep vertebral bodies. BUB amplitude patterns were observed and analyzed. Descriptive statistics were used. METHODS In vitro acoustic experiments on vertebral bodies in a water bath were performed with two 1-MHz unfocused transducers to measure sound speed, broadband US attenuation, and backscatter coefficients. Micro-CAT scan three-dimensional (3-D) images of 10 disarticulated vertebral bodies were obtained pre- and postdrilling done in 5-mm depth increments with a flat-bottom drill. BUB patterns were noted of transducers inserted through rostral outer cortex, through the pedicle, and advanced to the ventral marrow-cortex interface. 2.5-MHz FVT and SVT were co-advanced in successive 5-mm increments along the insertion pathway, with BUBs measured at each point and the echoes composited into a single figure. Deliberate perforations of ventral cortex were made. RESULTS Evident patterns or measures indicating the proximity of the ventral marrow-cortex interface were: 1) marrow BUB values increasing in amplitude over three distal peaks in most FVT cases (7 out of 10) and SVT cases (9 out of 10); 2) BUB ratio of marrow-cortex interface to the smallest marrow value greater than 2, in all FVT cases (10 out of 10) with FVT mean of 4.00+/-1.82 (2.25-8.33); and 3) a ratio of distal BUB value to starting cortex BUB in the 0. 82 to 1.62 range (mean, 0.98+/-0.30) in 80% of FVT cases. Ventral FVT perforations resulted in a major drop in the BUB value. CONCLUSIONS The increase in the BUB amplitudes in the distal insertion pathway suggests that, at least with a 2.5-MHz transducer, an approximate 1.5-cm US window exists in most cases, by which close approach of the ventral marrow-cortex interface could be anticipated. Other ratios may serve as stop criteria to prevent further drilling. A precipitous drop in BUB amplitude may be an indication of a cortex perforation.
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Affiliation(s)
- David T. Raphael
- Keck School of Medicine; USC University Hospital, 1500 San Pablo St., Los Angeles, CA 90033, cell: 818-399-9538 pager: 213-919-0484
| | - Jin Ho Chang
- Post-Doctoral Research Associate, NIH Medical Ultrasonic Transducer Resource Center, Denney Research Center, Univ. of Southern California, Los Angeles, CA 90089, Phone: 213-821-2651
| | - Yao Ping Zhang
- Research Associate, Dept. of Anesthesiology, Keck School of Medicine, Los Angeles, CA 90033, cell: 626-497-6698 phone: 323-409-2794
| | - David Kudija
- California Standoff, Inc., Paso Robles, CA, or cell: 805-610-1706
| | - Thomas C. Chen
- Dept. of Neurosurgery, Keck School of Medicine, USC University Hospital, 1500 San Pablo St., Los Angeles, CA 90033,
| | - K. Kirk Shung
- NIH Medical Ultrasonic Transducer Resource Center; Viterbi School of Engineering, University of Southern California, Denney Research Bldg. 139 (Mail code 1111), Los Angeles, CA, office ephone: 213-821-2653
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