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Photopoulos G, Hurry J, Bansal A, Miyanji F, Parent S, Murphy J, El-Hawary R. Differential vertebral body growth is maintained after vertebral body tethering surgery for idiopathic scoliosis: 4-year follow-up on 888 peri-apical vertebrae and 592 intervertebral discs. Spine Deform 2024:10.1007/s43390-024-00874-3. [PMID: 38634997 DOI: 10.1007/s43390-024-00874-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 03/30/2024] [Indexed: 04/19/2024]
Abstract
PURPOSE To radiographically evaluate if vertebral body tethering (VBT) can maintain differential peri-apical vertebral growth at medium-term follow-up of 4 years. METHODS A prospective, international, multicenter database was queried to identify idiopathic scoliosis patients treated with thoracic VBT. Concave vs. convex vertebral body height, vertebral wedging, and disc wedging of the 3 peri-apical vertebrae were measured by two independent observers at 5 timepoints (pre-operative to 4-year follow-up). RESULTS 65 skeletally immature patients (60 female, mean 12.8 years old, 21 with open triradiate cartilages) met inclusion criteria. Mean pre-operative maximum scoliosis of 50 ± 8° decreased significantly post-operatively to 27 ± 9° (p < 0.001), which remained stable at 4-year follow-up 30 ± 17° (p = 0.38 vs. post-operative). Mean instrumented scoliosis was 21 ± 14° at 4-year follow-up, which was significantly different than 4-year maximum scoliosis (p < 0.001). Mean pre-operative kyphosis of 30 ± 12° did not significantly change post-operatively (p = 1.0) and remained stable at 4-year follow-up (35 ± 18°; p = 0.05). Mean individual convex vertebral height increased from 17.7 ± 1.9 mm to 19.8 ± 1.5 mm (p < 0.001), while mean individual concave height increased from 14.8 ± 1.9 mm to 17.6 ± 1.6 mm (p < 0.001). Summing the peri-apical heights, the difference in height from pre-operative to 4-year follow-up was greater on the concave (8.3 ± 4.7 mm) than on the convex side (6.2 ± 4.7 mm) (p < 0.001). Mean individual vertebral wedging decreased from 6 ± 2° at pre-operative to 4 ± 2° at 4-year follow-up (p < 0.001). Mean total vertebral and disc wedging started at 29 ± 7° pre-operatively, decreased to 16 ± 6° at post-operative (p < 0.001), then further decreased to 14 ± 8° at 4-year follow-up (p < 0.001). Patients with open triradiate cartilages at the time of surgery had a larger height change over the 4 years compared to those with closed triradiate cartilages (p < 0.001). CONCLUSION Patients with idiopathic scoliosis treated with VBT demonstrated differential vertebral growth which was maintained at minimum 4-year follow-up. This effect was more pronounced in patients whose triradiate cartilages were open at the time of surgery. LEVEL OF EVIDENCE III.
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Affiliation(s)
- Gregory Photopoulos
- Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Division of Orthopedic Surgery, IWK Health Centre, Orthopaedic Clinic, IWK Health Centre, 5850 University Avenue, PO Box 9700, Halifax, NS, B3K 6R8, Canada
| | - Jennifer Hurry
- Division of Orthopedic Surgery, IWK Health Centre, Orthopaedic Clinic, IWK Health Centre, 5850 University Avenue, PO Box 9700, Halifax, NS, B3K 6R8, Canada
| | - Ankita Bansal
- Division of Orthopedic Surgery, IWK Health Centre, Orthopaedic Clinic, IWK Health Centre, 5850 University Avenue, PO Box 9700, Halifax, NS, B3K 6R8, Canada
| | - Firoz Miyanji
- Orthopaedics Research Department, BC Children's Hospital, Vancouver, BC, Canada
| | - Stefan Parent
- Department of Orthopaedics, CHU Sainte-Justine, Montreal, QC, Canada
- Department of Surgery, University of Montreal, Montreal, QC, Canada
| | - Joshua Murphy
- Department of Orthopaedic Surgery, Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - Ron El-Hawary
- Faculty of Medicine, Dalhousie University, Halifax, NS, Canada.
- Division of Orthopedic Surgery, IWK Health Centre, Orthopaedic Clinic, IWK Health Centre, 5850 University Avenue, PO Box 9700, Halifax, NS, B3K 6R8, Canada.
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Farivar D, Parent S, Miyanji F, Heffernan MJ, El-Hawary R, Larson AN, Andras LM, Skaggs DL. Concave and convex growth do not differ over tethered vertebral segments, even with open tri-radiate cartilage. Spine Deform 2023; 11:881-886. [PMID: 37004694 PMCID: PMC10261211 DOI: 10.1007/s43390-023-00683-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/18/2023] [Indexed: 04/04/2023]
Abstract
PURPOSE To assess the following hypotheses related to vertebral body tethering (VBT): 1. VBT is associated with asymmetric (concave > convex) increases in height over the instrumented vertebra. 2. The instrumented Cobb angle improves following VBT surgery with growth. METHODS This is a retrospective case series of pediatric patients from a multicenter scoliosis registry treated with VBT between 2013 to 2021. INCLUSION CRITERIA patients with standing radiographs at < 4 months and ≥ 2 years after surgery. Distances between the superior endplate of the UIV and the inferior endplate of the LIV were measured at the concave corner, mid-point, and convex corner of the endplates. The UIV-LIV angle was recorded. Subgroup analyses included comparing different Risser scores and tri-radiate cartilage (TRC) closed versus open using student t-tests. RESULTS 83 patients met inclusion criteria (92% female; age at time of surgery 12.5 ± 1.4 years) with mean follow-up time of 3.8 ± 1.4 years. Risser scores at surgery were: 0 (n = 33), 1 (n = 12), 2 (n = 10), 3 (n = 11), 4 (n = 12), and 5 (n = 5). Of the 33 Risser 0 patients, 17 had an open TRC, 16 had a closed TRC. The UIV-LIV distance at concave, middle, and convex points significantly increased from immediate post-op to final-follow-up for Risser 0 patients, but not for Risser 1-5 patients. Increases in UIV-LIV distance were not significantly different between concave, middle, and convex points for all groups. There was no significant improvement or worsening in UIV-LIV angle for any group. CONCLUSION At a mean of 3.8 years following VBT, 33 Risser 0 patients demonstrated significant growth in the instrumented segment, though there was no difference between concave or convex growth, even for patients with open TRC.
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Affiliation(s)
- Daniel Farivar
- Cedars-Sinai Spine, 444 S San Vicente Blvd, Ste 901, Los Angeles, CA, 90048, USA
| | - Stefan Parent
- Department of Surgery, Université de Montréal, Montreal, QC, Canada
| | - Firoz Miyanji
- Department of Orthopedics, BC Children's Hospital, Vancouver, BC, Canada
| | - Michael J Heffernan
- Children's Orthopaedic Center, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - Ron El-Hawary
- Orthopedics, Izaak Walton Killam (IWK) Health Centre, Halifax, Canada
| | - A Noelle Larson
- Department of Orthopedic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA
| | - Lindsay M Andras
- Children's Orthopaedic Center, Children's Hospital Los Angeles, Los Angeles, CA, USA
| | - David L Skaggs
- Cedars-Sinai Spine, 444 S San Vicente Blvd, Ste 901, Los Angeles, CA, 90048, USA.
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Raballand C, Cobetto N, Larson AN, Aubin CE. Prediction of post-operative adding-on or compensatory lumbar curve correction after anterior vertebral body tethering. Spine Deform 2023; 11:27-33. [PMID: 35986884 DOI: 10.1007/s43390-022-00558-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 07/23/2022] [Indexed: 11/28/2022]
Abstract
PURPOSE Anterior Vertebral Body Tethering (AVBT), a fusionless surgical technique based on growth modulation, aims to correct pediatric scoliosis over time. However, medium-term curvature changes of the non-instrumented distal lumbar curve remains difficult to predict. The objective was to biomechanically analyze the level below the LIV to evaluate whether adding-on or compensatory lumbar curve after AVBT can be predicted by intervertebral disc (ID) wedging and force asymmetry. METHODS 33 retrospective scoliotic cases instrumented with AVBT were used to computationally simulate their surgery and 2-year post-operative growth modulation using a finite element model. The cohort was divided into two subgroups according to the lumbar curvature evolution over 2 years: (1) correction > 10° (C); (2) maintaining ± 10° (M). The lumbar Cobb angle and residual ID wedging angle under LIV were measured. Simulated pressures and moments at the superior endplate of LIV + 1 were post-processed. These parameters were correlated at 2 years postoperatively. FINDINGS On average, the LIV + 1 simulated moment was 538 Nmm for subgroup C, 155 Nmm for subgroup M with lumbar Cobb angle > 20° and 34 Nmm for angle < 20° whereas the ID angle was 1° for C and 0° for M. INTERPRETATION On average, a positive moment on the LIV + 1 superior growth plate led to correction of the lumbar curvature, whereas a null moment kept it stable, and a parallel immediate postoperative ID under LIV contributed to its correction or preservation. Nevertheless, the significant interindividual variability suggested that other parameters are involved in the distal non-instrumented curvature evolution. LEVEL OF EVIDENCE IV.
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Affiliation(s)
- Charlotte Raballand
- Department of Mechanical Engineering, Polytechnique Montréal, Downtown Station, P.O. Box 6079, Montreal, QC, H3C 3A7, Canada
| | - Nikita Cobetto
- Department of Mechanical Engineering, Polytechnique Montréal, Downtown Station, P.O. Box 6079, Montreal, QC, H3C 3A7, Canada.,Research Center, Sainte-Justine University Hospital Center, 3175 Côte-Sainte-Catherine Road, Montreal, QC, H3T 1C5, Canada
| | - A Noelle Larson
- Department of Orthopedic Surgery, Mayo Clinic, 200 First Street Southwest, Rochester, MN, 55905, USA
| | - Carl-Eric Aubin
- Department of Mechanical Engineering, Polytechnique Montréal, Downtown Station, P.O. Box 6079, Montreal, QC, H3C 3A7, Canada. .,Research Center, Sainte-Justine University Hospital Center, 3175 Côte-Sainte-Catherine Road, Montreal, QC, H3T 1C5, Canada.
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Floman Y, El-Hawary R, Lonner BS, Betz RR, Arnin U. Vertebral growth modulation by posterior dynamic deformity correction device in skeletally immature patients with moderate adolescent idiopathic scoliosis. Spine Deform 2021; 9:149-153. [PMID: 32827087 PMCID: PMC7775858 DOI: 10.1007/s43390-020-00189-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 08/10/2020] [Indexed: 01/16/2023]
Abstract
STUDY DESIGN Retrospective, comparative, multicenter. INTRODUCTION Growth modulating spinal implants are used in the management of scoliosis such as anterior vertebral body tethering. A motion-sparing posterior device (PDDC) was recently approved for the treatment of moderate AIS. The purpose of this study was to determine if the PDDC can modulate growth in skeletally immature patients with AIS. METHODS From a database of patients treated with the PDDC over 4 years, we identified those who had a minimum of 2 years follow-up. Pre-operative and post-operative Cobb angles and coronal plane wedging of the apical vertebra were evaluated on standing full length radiographs. Independent sample t test and one-way ANOVA with post-hoc Tukey HSD analysis was used to compare three groups in varying skeletal maturity: Risser 0-1, Risser 2-3, and Risser 4-5. RESULTS 45 patients (14.2-years old, 11-17) were evaluated with a mean pre-op curve of 46° (35°-66°). The average preoperative major curve magnitude, of either Lenke 1 or 5 curve type, was similar among the three groups 47.6°, 46° and 41.5°. Deformity correction was similar in the three groups, with reduction to 26.4°, 20.4° and 26.2°, respectively, at final follow-up [p < 0.05]. Pre-op wedging 7.4° (3.8°-15°) was reduced after surgery to 5.7° (1°-15°) (p < 0.05). Of those patients, Risser 0-1 (n = 16) had preoperative wedging of 9.5° (6°-14.5°) that was reduced to 5.4° (1°-8°) postoperatively (p < 0.05); Risser 2-3 (n = 15) had pre-op 7.7° (4°-15°) vs. post-op 7.0° (3°-15°); Risser 4-5 (n = 14) had pre-op 4.8° (3.8°-6.5°) vs. post-op 4.7° (3.7°-6.5°). Delta Wedging in Risser 0-1 stage was significantly different than for Risser 2-3 and for Risser 4-5. CONCLUSION The posterior dynamic deformity correction device was able to modulate vertebral body wedging in skeletally immature patients with AIS. This was most evident in patients who were Risser 0-1. In contrast, curve correction was similar among the three groups. This finding lends support to the device's ability to modulate growth.
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Affiliation(s)
- Yizhar Floman
- Israel Spine Center, Assuta Hospital, 20 Habarzel, Tel Aviv, Israel.
| | - Ron El-Hawary
- grid.414870.e0000 0001 0351 6983Division of Orthopedic Surgery, IWK Health Center, University Ave, PO Box 9700, Halifax, NS 5850 B3K-6R8 Canada
| | - Baron S. Lonner
- grid.416167.3Mount Sinai Hospital, 1468 Madison Ave, New York, NY 10029 USA
| | - Randal R. Betz
- Institute for Spine and Scoliosis, 3100 Princeton Pike, Lawrenceville, NJ USA
| | - Uri Arnin
- ApiFix LTD, Kochav Yokneam Bldg, 1 Hacarmel street, Yokneam Ilit, Israel
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