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Du ZS, Wang YS, Xie JM, Li T, Shi ZY, Lu QA, Zhang Y, Zhao Z, Bi N, Song ZB, Zhu TB. Feasibility of microwave ablation of the vertebral growth plate for spine growth regulation: a preliminary study. Int J Hyperthermia 2021; 38:1233-1241. [PMID: 34396870 DOI: 10.1080/02656736.2021.1964619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
PURPOSE To explore the feasibility of microwave ablation (MWA) of the vertebral growth plate as a minimally invasive treatment for early-onset scoliosis. MATERIALS AND METHODS One side of the L1-L3 vertebral growth plates were ablated using different MWA powers. Ablation safety and size were examined. Subsequently, L1-L3 vertebral growth plates were ablated on one side for 40 s at 20 W. At 2, 4, and 6 weeks after the ablation, growth changes of the spine were observed. RESULTS No piglets died during and after ablation, and all had modified Tarlov Grade 5. The safe MWA time (time for safely ablating the vertebral growth plate) was 17.0 ± 1.5 s at 50 W, 23.0 ± 2.3 s at 40 W, 31.0 ± 3.1 s at 30 W, 47.0 ± 3.7 s at 20 W, 70.0 ± 4.2 s at 15 W, and 158.0 ± 5.0 s at 10 W. With power <15 W, the vertebral growth plate could not be effectively ablated within the safe ablation time. Within the safe ablation times, the MWA size on hematoxylin and eosin slices on a transverse diameter was between 7 and 10 mm; and that on longitudinal diameter was mainly determined by the ablation needle length. Moreover, the growth plate and annulus fibrosus on the ablated side grew poorly over time, the vertebral body showed significant wedge-shaped changes, and the spine showed significant unbalanced growth. CONCLUSION MWA of the vertebral growth plate can be performed safely when accompanied with appropriate thermometry, and could be a new minimally invasive strategy in regulating spine growth.
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Affiliation(s)
- Zhi-Shan Du
- Department of Orthopedics, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Ying-Song Wang
- Department of Orthopedics, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Jing-Ming Xie
- Department of Orthopedics, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Tao Li
- Department of Orthopedics, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Zhi-Yue Shi
- Department of Orthopedics, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Qiu-An Lu
- Department of Orthopedics, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Ying Zhang
- Department of Orthopedics, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Zhi Zhao
- Department of Orthopedics, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Ni Bi
- Department of Orthopedics, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Zhi-Bo Song
- Department of Orthopedics, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Ting-Biao Zhu
- Department of Orthopedics, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
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Amundson LA, Crenshaw TD. Lessons learned from the hypovitaminosis D kyphotic pig model. J Anim Sci 2020; 98:S52-S57. [PMID: 32810238 DOI: 10.1093/jas/skaa146] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 05/04/2020] [Indexed: 12/20/2022] Open
Affiliation(s)
- Laura A Amundson
- Department of Animal Sciences, University of Wisconsin Madison, Madison, WI.,Research and Nutritional Services, Zinpro Corporation, Eden Prairie, MN
| | - Thomas D Crenshaw
- Department of Animal Sciences, University of Wisconsin Madison, Madison, WI
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Jaramillo AM, Aubin CÉ, Hachem B, Londono I, Pelletier J, Parent S, Villemure I. Mechanobiological analysis of porcine spines instrumented with intra-vertebral staples. JOURNAL OF MUSCULOSKELETAL & NEURONAL INTERACTIONS 2019; 19:13-20. [PMID: 30839299 PMCID: PMC6454252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To characterize growth plate histology of porcine spines instrumented with a new intra-vertebral staple. METHODS Spinal segments (T7-T9) previously instrumented with an intra-vertebral staple (experimental group, n=7) or non-instrumented (control group, n=4) underwent average growth rate (AGR), and histomorphometric measurements: heights of proliferative (PZH) and hypertrophic (HZH) growth plate zones, hypertrophic cells height (CH), and the number of proliferative chondrocytes per column (CC). These measurements were done over three regions: (1) left side; (2) middle; (3) right side (instrumented side). The two groups were analyzed by comparing the difference between results for regions 1 and 3 (Dif-R1R3). RESULTS A significantly higher Dif-R1R3 was found for AGR and HZH for the experimental group as compared with controls. This Dif-R1R3 was also significantly higher for CC at T8 level, CH at T7 level and PZH at both levels. No significant changes for the Dif-R1R3 were observed in the adjacent vertebrae (T11-T12). CONCLUSIONS This study confirmed the local growth modulation capacity of the intra-vertebral staple, translated at the histomorphometric level by a significant reduction in all parameters, but not in all spinal levels. Further analyses are needed to confirm the regional effect, especially for the intervertebral disc and other connective tissues.
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Affiliation(s)
| | - Carl-Éric Aubin
- Polytechnique Montréal, Canada,Sainte-Justine University Hospital Center, Canada,Univerisity of Montreal, Canada
| | - Bahe Hachem
- Polytechnique Montréal, Canada,Sainte-Justine University Hospital Center, Canada
| | | | | | - Stefan Parent
- Sainte-Justine University Hospital Center, Canada,Univerisity of Montreal, Canada
| | - Isabelle Villemure
- Polytechnique Montréal, Canada,Sainte-Justine University Hospital Center, Canada,Corresponding author: Isabelle Villemure, PhD Full Professor, Department of Mechanical Engineering, Polytechnique Montréal, C.P. 6079, Downtown Office, Montreal, Quebec, CANADA H3C 3A7 E-mail:
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Halanski MA, Hildahl B, Amundson LA, Leiferman E, Gendron-Fitzpatrick A, Chaudhary R, Hartwig-Stokes HM, McCabe R, Lenhart R, Chin M, Birstler J, Crenshaw TD. Maternal Diets Deficient in Vitamin D Increase the Risk of Kyphosis in Offspring: A Novel Kyphotic Porcine Model. J Bone Joint Surg Am 2018; 100:406-415. [PMID: 29509618 PMCID: PMC6818982 DOI: 10.2106/jbjs.17.00182] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND The purpose of this study was to explore the role of perinatal vitamin-D intake on the development and characterization of hyperkyphosis in a porcine model. METHODS The spines of 16 pigs were assessed at 9, 13, and 17 weeks of age with radiography and at 17 weeks with computed tomography (CT), magnetic resonance imaging (MRI), histology, and bone-density testing. An additional 169 pigs exposed to 1 of 3 maternal dietary vitamin-D levels from conception through the entire lactation period were fed 1 of 4 nursery diets supplying different levels of vitamin D, calcium, and phosphorus. When the animals were 13 weeks of age, upright lateral spinal radiography was performed with use of a custom porcine lift and sagittal Cobb angles were measured in triplicate to determine the degree of kyphosis in each pig. RESULTS The experimental animals had significantly greater kyphotic sagittal Cobb angles at all time points when compared with the control animals. These hyperkyphotic deformities demonstrated no significant differences in Hounsfield units, contained a slightly lower ash content (46.7% ± 1.1% compared with 50.9% ± 1.6%; p < 0.001), and demonstrated more physeal irregularities. Linear mixed model analysis of the measured kyphosis demonstrated that maternal diet had a greater effect on sagittal Cobb angle than did nursery diet and that postnatal supplementation did not completely eliminate the risk of hyperkyphosis. CONCLUSIONS Maternal diets deficient in vitamin D increased the development of hyperkyphosis in offspring in this model. CLINICAL RELEVANCE This study demonstrates that decreased maternal dietary vitamin-D intake during pregnancy increases the risk of spinal deformity in offspring. In addition, these data show the feasibility of generating a large-animal spinal-deformity model through dietary manipulation alone.
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Affiliation(s)
- Matthew A. Halanski
- Departments of Orthopedics and Rehabilitation (M.A.H., B.H., E.L., R.C., H.M.H.-S., R.M., and R.L.) and Animal Sciences (L.A.A. and T.D.C.), Comparative Pathology Laboratory (A.G.-F.), and Department of Biostatistics and Medical Informatics (J.B.), University of Wisconsin-Madison, Madison, Wisconsin,E-mail address for M.A. Halanski:
| | - Blake Hildahl
- Departments of Orthopedics and Rehabilitation (M.A.H., B.H., E.L., R.C., H.M.H.-S., R.M., and R.L.) and Animal Sciences (L.A.A. and T.D.C.), Comparative Pathology Laboratory (A.G.-F.), and Department of Biostatistics and Medical Informatics (J.B.), University of Wisconsin-Madison, Madison, Wisconsin
| | - Laura A. Amundson
- Departments of Orthopedics and Rehabilitation (M.A.H., B.H., E.L., R.C., H.M.H.-S., R.M., and R.L.) and Animal Sciences (L.A.A. and T.D.C.), Comparative Pathology Laboratory (A.G.-F.), and Department of Biostatistics and Medical Informatics (J.B.), University of Wisconsin-Madison, Madison, Wisconsin
| | - Ellen Leiferman
- Departments of Orthopedics and Rehabilitation (M.A.H., B.H., E.L., R.C., H.M.H.-S., R.M., and R.L.) and Animal Sciences (L.A.A. and T.D.C.), Comparative Pathology Laboratory (A.G.-F.), and Department of Biostatistics and Medical Informatics (J.B.), University of Wisconsin-Madison, Madison, Wisconsin
| | - Annette Gendron-Fitzpatrick
- Departments of Orthopedics and Rehabilitation (M.A.H., B.H., E.L., R.C., H.M.H.-S., R.M., and R.L.) and Animal Sciences (L.A.A. and T.D.C.), Comparative Pathology Laboratory (A.G.-F.), and Department of Biostatistics and Medical Informatics (J.B.), University of Wisconsin-Madison, Madison, Wisconsin
| | - Rajeev Chaudhary
- Departments of Orthopedics and Rehabilitation (M.A.H., B.H., E.L., R.C., H.M.H.-S., R.M., and R.L.) and Animal Sciences (L.A.A. and T.D.C.), Comparative Pathology Laboratory (A.G.-F.), and Department of Biostatistics and Medical Informatics (J.B.), University of Wisconsin-Madison, Madison, Wisconsin
| | - Heather M. Hartwig-Stokes
- Departments of Orthopedics and Rehabilitation (M.A.H., B.H., E.L., R.C., H.M.H.-S., R.M., and R.L.) and Animal Sciences (L.A.A. and T.D.C.), Comparative Pathology Laboratory (A.G.-F.), and Department of Biostatistics and Medical Informatics (J.B.), University of Wisconsin-Madison, Madison, Wisconsin
| | - Ronald McCabe
- Departments of Orthopedics and Rehabilitation (M.A.H., B.H., E.L., R.C., H.M.H.-S., R.M., and R.L.) and Animal Sciences (L.A.A. and T.D.C.), Comparative Pathology Laboratory (A.G.-F.), and Department of Biostatistics and Medical Informatics (J.B.), University of Wisconsin-Madison, Madison, Wisconsin
| | - Rachel Lenhart
- Departments of Orthopedics and Rehabilitation (M.A.H., B.H., E.L., R.C., H.M.H.-S., R.M., and R.L.) and Animal Sciences (L.A.A. and T.D.C.), Comparative Pathology Laboratory (A.G.-F.), and Department of Biostatistics and Medical Informatics (J.B.), University of Wisconsin-Madison, Madison, Wisconsin
| | - Matthew Chin
- Geisinger Wyoming Valley Medical Center, Wilkes-Barre, Pennsylvania
| | - Jennifer Birstler
- Departments of Orthopedics and Rehabilitation (M.A.H., B.H., E.L., R.C., H.M.H.-S., R.M., and R.L.) and Animal Sciences (L.A.A. and T.D.C.), Comparative Pathology Laboratory (A.G.-F.), and Department of Biostatistics and Medical Informatics (J.B.), University of Wisconsin-Madison, Madison, Wisconsin
| | - Thomas D. Crenshaw
- Departments of Orthopedics and Rehabilitation (M.A.H., B.H., E.L., R.C., H.M.H.-S., R.M., and R.L.) and Animal Sciences (L.A.A. and T.D.C.), Comparative Pathology Laboratory (A.G.-F.), and Department of Biostatistics and Medical Informatics (J.B.), University of Wisconsin-Madison, Madison, Wisconsin,Swine Research and Teaching Center, Arlington, Wisconsin,E-mail address for T.D. Crenshaw:
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Barrios C, Lloris JM, Alonso J, Maruenda B, Burgos J, Llombart-Blanco R, Gil L, Bisbal V. Novel porcine experimental model of severe progressive thoracic scoliosis with compensatory curves induced by interpedicular bent rigid temporary tethering. J Orthop Res 2018; 36:174-182. [PMID: 28548698 DOI: 10.1002/jor.23617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 05/19/2017] [Indexed: 02/04/2023]
Abstract
UNLABELLED Using flexible tethering techniques, porcine models of experimental scoliosis have shown scoliotic curves with vertebral wedging but very limited axial rotation. The aim of this experimental work was to induce a severe progressive scoliosis in a growing porcine model for research purposes. A unilateral spinal bent rigid tether was anchored to two ipsilateral pedicle screws in eight pigs. The spinal tether was removed after 8 weeks. Ten weeks later, the animals were sacrificed. Conventional radiographs and 3D CT-scans were taken to evaluate changes in the alignment of the thoracic spine. After the first 8 weeks of rigid tethering, all animals developed scoliotic curves (mean Cobb angle: 24.3°). Once the interpedicular tether was removed, the scoliotic curves progressed in all animals during 10 weeks reaching a mean Cobb angle of 49.9°. The sagittal alignment of the thoracic spine showed loss of physiologic kyphosis (Mean: -18.3°). Axial rotation ranged from 10° to 49° (Mean 25.7°). Release of the spinal tether results in progression of the deformity with the development of proximal and distal compensatory curves. In conclusion, temporary interpedicular tethering at the thoracic spine induces severe scoliotic curves in pigs, with significant wedging and rotation of the vertebral bodies, and true compensatory curves. CLINICAL RELEVANCE The tether release model will be used to evaluate corrective non-fusion technologies in future investigations. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:174-182, 2018.
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Affiliation(s)
- Carlos Barrios
- lnstitute for Research on Musculoskeletal Disorders, Valencia Catholic University, Valencia, Spain
| | - José Miguel Lloris
- Department of Surgery, Valencia University Medical School, Valencia, Spain
| | - Juan Alonso
- lnstitute for Research on Musculoskeletal Disorders, Valencia Catholic University, Valencia, Spain
| | - Borja Maruenda
- Department of Orthopedic Surgery, Hospital de la Ribera, Alzira, Valencia, Spain
| | - Jesús Burgos
- Division of Pediatric Orthopedics, Hospital Ramon y Cajal, Madrid, Spain
| | | | - Luis Gil
- lnstitute for Research on Musculoskeletal Disorders, Valencia Catholic University, Valencia, Spain
| | - Viviana Bisbal
- Animal Facility Services, Prince Felipe Research Center, Valencia, Spain
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Cachon T, Pillard P, Odent T, Carozzo C, Viguier E. Safe corridor for the implantation of thoracolumbar pedicle screws in growing pigs: A morphometric study. PLoS One 2017; 12:e0184857. [PMID: 29059193 PMCID: PMC5653201 DOI: 10.1371/journal.pone.0184857] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Accepted: 09/02/2017] [Indexed: 12/17/2022] Open
Abstract
The pig spine is widely used as a large animal model for preclinical research in human medicine to test new spinal implants and surgical procedures. Among them, pedicle screw is one of the most common method of fixation of those implants. However, the pedicle of the porcine vertebra is not as well defined and not as large as the pedicle of the human vertebra. Therefore, the position of the screw should be adapted to the pig and not merely transposed based on the literature on humans. The purpose of this study is to determine the characteristics of the optimum implantation corridors for pedicle screws in the thoracolumbar spine of piglets of different ages using computed tomography (CT) and to determine the size and length of these corridors in pigs of different ages. CT scans from five groups of age: 6, 10, 14, 18, and 26 weeks were reviewed. For each thoracolumbar vertebrae, the pedicle width, pedicle axis length, and the pedicle angle was measured for the left and right pedicle. A total of 326 thoracic vertebrae and 126 lumbar vertebrae were included in the study. Pedicles are statistically larger but not longer for the lumbar vertebrae. An important variation of the pedicle angle is observed along the spine. In all pigs, an abrupt modification of the pedicle angle between T10 and T11 was observed, which corresponds to the level of the anticlinal vertebra which is the vertebra for which the spinous process is nearly perpendicular to the vertebral body. In conclusion, this study provides a quantitative database of pedicle screw implantation corridors in pigs of different ages. When using pedicle screws in experimental studies in pigs, these results should be considered for selecting the most suitable implants for the study but also to ensure a correct and safer screw position. Improving study procedures may limit postoperative complications and pain, thereby limiting the use of live animals.
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Affiliation(s)
- Thibaut Cachon
- Unité ICE (USPS 2016-A104.) Campus Vétérinaire de Lyon-VetAgro-Sup, MARCY L’ETOILE, FRANCE
- * E-mail:
| | - Paul Pillard
- Unité ICE (USPS 2016-A104.) Campus Vétérinaire de Lyon-VetAgro-Sup, MARCY L’ETOILE, FRANCE
| | - Thierry Odent
- CHU Tours - Hôpital d'enfants Clocheville- Service de Chirurgie Orthopédique pédiatrique, TOURS, FRANCE
| | - Claude Carozzo
- Unité ICE (USPS 2016-A104.) Campus Vétérinaire de Lyon-VetAgro-Sup, MARCY L’ETOILE, FRANCE
| | - Eric Viguier
- Unité ICE (USPS 2016-A104.) Campus Vétérinaire de Lyon-VetAgro-Sup, MARCY L’ETOILE, FRANCE
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Porcine spine finite element model: a complementary tool to experimental scoliosis fusionless instrumentation. 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; 26:1610-1617. [DOI: 10.1007/s00586-016-4940-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 12/21/2016] [Accepted: 12/25/2016] [Indexed: 10/20/2022]
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Novel Hemi-Staple for the Fusionless Correction of Pediatric Scoliosis: Influence on Intervertebral Disks and Growth Plates in a Porcine Model. Clin Spine Surg 2016; 29:457-464. [PMID: 27755203 DOI: 10.1097/bsd.0b013e31828b2f15] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
STUDY DESIGN In vivo porcine model utilized to evaluate the influence of an intravertebral fusionless growth modulating device (hemi-staple) on intervertebral disks and growth plates. OBJECTIVE To evaluate the radiographic and histologic changes in disks and growth plates with the purpose of measuring influence of the explored hemi-staple. SUMMARY OF BACKGROUND DATA Fusionless growth modulation for the early treatment of scoliosis should insure the long-term viability of the intervertebral disk and successfully reduce or arrest local growth. A novel hemi-staple that proved effective in the control of coronal spinal alignment warranted further analyses of its influence on the disk health and growth-plate morphology. METHODS A hemi-staple that inhibited local vertebral growth exclusive of the disk was introduced over T5-T8 in 4 immature pigs (16 vertebrae; experimental), whereas 3 underwent surgery without instrumentation (sham) and 2 had no intervention (control). Three-month follow-up before animal euthanasia provided radiographic (disk height and health) and histologic (growth plate morphology, disk health, and type X collagen distribution) analyses. RESULTS No postoperative complications were experienced. Radiographic data returned inverse disk wedging (greater disk height adjacent to device, 2.6±0.7 mm compared with the noninstrumented side, 1.8±0.5 mm) in experimental segments and suggested disk viability. Histologic data confirmed device growth modulation through significant local reduction of growth plate hypertrophic zone (125.64±16.61 μm and 61.16±8.25 μm in noninstrumented and instrumented sections, respectively) and cell height (16.14±1.87 μm and 9.22±1.57 μm in noninstrumented and instrumented sections, respectively). A variability of disk health, dependant of device insertion location, was observed. Type X collagen was consistently identified in experimental growth plates and absent from intervertebral disks. CONCLUSIONS Hemi-staples decreased growth plate hypertrophic zone and cell height, and, depending on device insertion site, showed positive signs of disk health sustainability. Spinal growth modulation achieved exclusive of disk compression, as practiced by this method, offers unique advantages over other fusionless techniques. This technique may provide a suitable and attractive alternative for the early treatment of idiopathic scoliosis.
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Local Epiphyseal Growth Modulation for the Early Treatment of Progressive Scoliosis: Experimental Validation Using a Porcine Model. Spine (Phila Pa 1976) 2016; 41:E1009-E1015. [PMID: 26863259 DOI: 10.1097/brs.0000000000001496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Experimental study of a localized device for the control of the vertebral growth using an immature porcine model. OBJECTIVE The aim of the study was to experimentally evaluate a localized device acting on the epiphyseal growth plates without bridging the intervertebral disc of immature hybrid pigs over 3 months of growth. SUMMARY OF BACKGROUND DATA Based on current published literature, fusionless devices offer promising scoliosis treatment alternatives to conventional spinal instrumentation and fusion in the growing spine. Current compression-based devices achieve growth modulation while also compressing the intervertebral discs, increasing the risk of long-term disc degeneration. METHODS An intravertebral staple acting on both the superior and inferior growth plates was inserted locally over T7-T9 of seven healthy immature pigs. Four age-matched animals served as controls. Radiographs were acquired monthly to assess induced spinal curvature and vertebral wedging (inverse model). Global (spinal) and local (vertebral, discal) geometric changes were evaluated over 3-months follow-up. Final left/right vertebral height differences were also quantified. RESULTS The only postoperative complication observed was one pig that had a persistent deep infection and was excluded from the study. No significant changes in spinal alignment were reported in control animals. Final induced Cobb angle was 25.0° ± 4.2° measured over T7-T9, with no observable sagittal profile modification. Highest vertebral wedging occurred at T9 with 18.2° ± 2.7°. Cumulative vertebral wedging over T7-T9 accounted for 45.4°, demonstrating evidence of reversed disc wedge phenomenon. Vertebral height was 3.9 ± 1.0 mm shorter on the instrumented side suggesting full growth restraint. Local and regional induced deformities significantly differed from their control counterparts (P < 0.001). CONCLUSION In this animal model, the local epiphyseal device achieved significant localized growth modulation over as little as three instrumented levels, with explicit vertebral wedging exclusive of the intervertebral disc. By increasing the number of instrumented levels, one may achieve higher curvature control potentially providing a unique local correction method to correct spinal deformity without affecting the intervertebral disc. LEVEL OF EVIDENCE 5.
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Benoit A, Mustafy T, Londono I, Beaudry F, Vachon P, Grimard G, Aubin CE, Villemure I. Histomorphometry of the newly formed bone after its growth modulation by static and dynamic compression using a rat tail model. Comput Methods Biomech Biomed Engin 2015; 18 Suppl 1:1884-5. [PMID: 26292155 DOI: 10.1080/10255842.2015.1069554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- A Benoit
- a International Associated Laboratory in Biomechanics of Spine Injuries & Pathologies.,b Ecole Polytechnique, Department of Mechanical Engineering , Succursale Centre Ville , Montreal , Canada.,c St Justine University Hospital Center, Research Center , Montreal , Canada
| | - T Mustafy
- b Ecole Polytechnique, Department of Mechanical Engineering , Succursale Centre Ville , Montreal , Canada.,c St Justine University Hospital Center, Research Center , Montreal , Canada
| | - I Londono
- c St Justine University Hospital Center, Research Center , Montreal , Canada
| | - F Beaudry
- d Faculté de médecine vétérinaire, Département de biomédecine vétérinaire , Université de Montréal , Saint-Hyacinthe , Canada
| | - P Vachon
- d Faculté de médecine vétérinaire, Département de biomédecine vétérinaire , Université de Montréal , Saint-Hyacinthe , Canada
| | - G Grimard
- c St Justine University Hospital Center, Research Center , Montreal , Canada
| | - C-E Aubin
- a International Associated Laboratory in Biomechanics of Spine Injuries & Pathologies.,b Ecole Polytechnique, Department of Mechanical Engineering , Succursale Centre Ville , Montreal , Canada.,c St Justine University Hospital Center, Research Center , Montreal , Canada
| | - I Villemure
- b Ecole Polytechnique, Department of Mechanical Engineering , Succursale Centre Ville , Montreal , Canada.,c St Justine University Hospital Center, Research Center , Montreal , Canada
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Biomechanical simulation and analysis of scoliosis correction using a fusionless intravertebral epiphyseal device. Spine (Phila Pa 1976) 2015; 40:369-76. [PMID: 25584943 DOI: 10.1097/brs.0000000000000777] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Computer simulations to analyze the biomechanics of a novel compression-based fusionless device (hemistaple) that does not cross the disc for the treatment of adolescent idiopathic scoliosis. OBJECTIVE To biomechanically model, simulate, and analyze the hemistaple action using a human finite element model (FEM). SUMMARY OF BACKGROUND DATA A new fusionless growth sparing instrumentation device (hemistaple), which locally compresses the growth plate without spanning the disc, was previously developed and successively tested on different animal models. METHODS Patient-specific FEMs of the spine, rib cage, and pelvis were built using radiographs of 10 scoliotic adolescents (11.7 ± 0.9 yr; Cobb thoracic: 35° ± 7°, lumbar: 24° ± 6°). A validated algorithm allowed simulating the growth (0.8-1.1 mm/yr/vertebra) and growth modulation process (Hueter-Volkmann principle) during a period of 2 years. Four instrumentation configurations on the convex curves were individually simulated (Config 1: 5 thoracic vertebrae with hemistaples on superior endplates; Config 2: same as Config 1 with hemistaples on both endplates; Config 3: same as Config 1 + 4 lumbar vertebrae; Config 4: same as Config 2 + 4 lumbar vertebrae). RESULTS Without hemistaples, on average the thoracic and lumbar Cobb angles, respectively, progressed from 35° to 56° and 24° to 30°, whereas the vertebral wedging at curve apices progressed from 5° to 12°. With the hemistaple Config 1, the Cobb angles progressed but were limited to 42° and 26°, whereas the wedging ended at 8°. With Config 3, Cobb and wedging were kept nearly constant (38°, 21°, 7°). With hemistaples on both endplates (Config 2, Config 4), the Cobb and wedging were all reduced (thoracic Cobb for Config 2 and 4: 24° and 15°; lumbar Cobb: 21° and 11°; wedging: 2° and 1°). CONCLUSION This study suggests that the hemistaple has the biomechanical potential to control the scoliosis progression and highlights the importance of the instrumentation configuration to correct the spinal deformities. It biomechanically supports the new fusionless device concept as an alternative for the early treatment of idiopathic scoliosis. LEVEL OF EVIDENCE 5.
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Modulation of spinal shape with growth following implantation of a novel surgical implant. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2014; 24:1522-32. [PMID: 25304648 DOI: 10.1007/s00586-014-3610-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Accepted: 10/01/2014] [Indexed: 10/24/2022]
Abstract
PURPOSE First, to determine whether scoliosis development could be limited or reversed by growth when a novel modular hinged implant was fixed to the convexity of a scoliosis created by contralateral rib and laminar tethering and unilateral rib resection in a sheep model. Second, to assess the effect and performance of the implant in normal non-tethered sheep. METHODS At 5 weeks, 20 Scottish Blackface lambs underwent surgery to create a right sided scoliosis by (i) tethering the left lamina of T5-L1 and the left lower six ribs and (ii) resecting a segment of their right lower six ribs [1, 2]. Twelve weeks later, through an antero-lateral thoracotomy, a mobile bi-planar hinged implant was inserted onto the right side of the spine of eight animals (group 1). For comparison, 12 sheep were tethered only but had no implant insertion (group 2). In addition, seven had no tethering but were implanted (group 3) and normal growth patterns were observed in five that had no surgery (group 4). Curve progression was assessed by plain radiography and CT over a 1-year period. RESULTS Before implant insertion the trial animals had a scoliosis of 35º ± 16º and a lordosis of 44º ± 20º (n = 8, mean ± SD). Surgery immediately reduced these values to 25º ± 14º, p < 0.01 and 35º ± 18º, p < 0.001, with scoliosis continuing to decrease during the next three months. Spinal flexibility was retained. In the un-tethered sheep, a scoliosis of 10º ± 6º was created on the opposite side to the implant (p < 0.05) with no significant change in alignment in the sagittal plane (1º ± 6º). The implant did not cause any adverse effect on growth or affect neurological function. CONCLUSIONS In the un-tethered animals the effect of the implant was to create a scoliotic deformity and in the tethered to improve deformity while maintaining spinal motion. We believe that the results are promising and that devices of similar construct may be of use in children with scoliosis, potentially changing current methods of clinical care.
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Roth AK, Bogie R, Jacobs E, Arts JJ, van Rhijn LW. Large animal models in fusionless scoliosis correction research: a literature review. Spine J 2013; 13:675-88. [PMID: 23582429 DOI: 10.1016/j.spinee.2013.02.043] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 02/18/2013] [Accepted: 02/18/2013] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Numerous prenatal, systemic, or local procedures have been described that have created an experimental scoliosis within different animal species. Compression-based fusionless scoliosis correction devices have been used to induce scoliosis (inverse approach) as an indication for their potential corrective efficacy in large animals. Deformities that most closely approximate the three-dimensional nature of an idiopathic-like scoliosis have been created in large animals using a posterior spinal tether. Fusionless scoliosis correction devices have subsequently been tested in these models. PURPOSE To provide an overview of large animal models used for preclinical testing of fusionless scoliosis correction devices and to describe recent advances in the creation of an idiopathic-like scoliosis large animal model. STUDY DESIGN Literature review of large animal models in fusionless scoliosis correction research. METHODS MEDLINE electronic database was searched for studies in which large animal models for spinal or vertebral growth modulation or the creation of an experimental scoliosis were described. The literature search was limited to articles written in the English language. RESULTS The pig appears to be the most suitable animal species for preclinical testing of fusionless scoliosis correction devices because of its large growth potential and the possibility for early weaning. With the inverse approach, it is difficult to gain insight into the possible corrective efficacy of the tested device, and therefore, a two-step approach is preferred. Using a posterior spinal tether, persistent spinal deformities are attained when the deformity has approximately doubled in comparison to the postoperative measure in a time span of approximately 12 weeks. Sufficient tether midline offset is required to render rib procedures unnecessary. CONCLUSIONS An idiopathic-like scoliosis animal model can be created using a posterior spinal tether in a fully reversible procedure. Experimental results will need to be reproduced to establish a standard idiopathic-like scoliosis large animal model.
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Affiliation(s)
- Alex K Roth
- Department of Orthopaedic Surgery, Research School Caphri, Maastricht University Medical Centre, P. Debyelaan 25, 6229 HX Maastricht, The Netherlands
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Beaudette K, Strupler M, Benboujja F, Parent S, Aubin CE, Boudoux C. Optical coherence tomography for the identification of musculoskeletal structures of the spine: a pilot study. BIOMEDICAL OPTICS EXPRESS 2012; 3:533-542. [PMID: 22435100 PMCID: PMC3296540 DOI: 10.1364/boe.3.000533] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 02/01/2012] [Accepted: 02/04/2012] [Indexed: 05/31/2023]
Abstract
Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional deformity of the spine requiring in severe cases invasive surgery. Here, we explore the potential of optical coherence tomography (OCT) as a guiding tool for novel fusionless minimally invasive spinal surgeries on an ex vivo porcine model. We show that OCT, despite its limited penetration depth, may be used to precisely locate structures such as growth plate, bone and intervertebral disk using relative attenuation coefficients. We further demonstrate a segmentation algorithm that locates growth plates automatically on en-face OCT reconstructions.
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Affiliation(s)
- Kathy Beaudette
- Engineering Physics Department, École Polytechnique de Montréal, P.O. Box 6079, Station Centre-ville, Montreal, Quebec, Canada
- Sainte-Justine University Hospital Center, 3175, Côte Sainte-Catherine Road, Montreal, Quebec, Canada
| | - Mathias Strupler
- Engineering Physics Department, École Polytechnique de Montréal, P.O. Box 6079, Station Centre-ville, Montreal, Quebec, Canada
- Sainte-Justine University Hospital Center, 3175, Côte Sainte-Catherine Road, Montreal, Quebec, Canada
| | - Fouzi Benboujja
- Engineering Physics Department, École Polytechnique de Montréal, P.O. Box 6079, Station Centre-ville, Montreal, Quebec, Canada
- Sainte-Justine University Hospital Center, 3175, Côte Sainte-Catherine Road, Montreal, Quebec, Canada
| | - Stefan Parent
- Sainte-Justine University Hospital Center, 3175, Côte Sainte-Catherine Road, Montreal, Quebec, Canada
| | - Carl-Eric Aubin
- Mechanical Engineering Department, École Polytechnique de Montréal, P.O. Box 6079, Station Centre-ville, Montreal, Quebec, Canada
- Sainte-Justine University Hospital Center, 3175, Côte Sainte-Catherine Road, Montreal, Quebec, Canada
| | - Caroline Boudoux
- Engineering Physics Department, École Polytechnique de Montréal, P.O. Box 6079, Station Centre-ville, Montreal, Quebec, Canada
- Sainte-Justine University Hospital Center, 3175, Côte Sainte-Catherine Road, Montreal, Quebec, Canada
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