Do Multilevel Ponte Osteotomies in Thoracic Idiopathic Scoliosis Surgery Improve Curve Correction and Restore Thoracic Kyphosis?

Abstract Background The optimal anchor density in adolescent idiopathic scoliosis (AIS) surgery to achieve good curve correction remains unclear. The purpose of the study is to analyze the correlations between three-dimensional curve correction and anchor density in the pedicle screw-based posterior fusion of AIS. Methods One hundred and twenty-seven AIS patients receiving primary posterior fusion with pedicle screw instrumentation were retrospectively reviewed. Anchor density (AD) was defined as the screws number per fused spinal segment. The correlations between three-dimensional curve correction radiographic parameters and anchor density were analyzed with subgroup analysis based on different curve types, curve magnitudes, and curve flexibilities. The differences of curve correction parameters between the low-density (AD ≤1.4), middle-density (1.4 < AD ≤1.7) and high-density (AD > 1.7) groups were also calculated. Independent t-test, analysis of variance (ANOVA), and Pearson’s correlation coefficient were used for statistical analysis. Results There were no correlations between the anchor density and the coronal curve correction or apical vertebral rotation (AVR) correction. In the sagittal plane, mild positive correlations existed between anchor density and thoracic kyphosis correction in all patients (r = 0.27, p = 0.002). Subgroup analysis revealed similar mild positive correlations in Lenke 1 (r = 0.31, p = 0.02), Lenke 1–3 (r = 0.27, p = 0.01), small curves (40°-60°, r = 0.38, p < 0.001), and flexible curves (flexibility > 40%, r = 0.34, p = 0.01). There were no differences between low-density (mean 1.31), middle-density (mean 1.55), and high-density (mean 1.83) in terms of coronal or axial curve correction parameters. Low-density group has longer fused level (mean difference 2.14, p = 0.001) and smaller thoracic kyphosis correction (mean difference 9.25°, p = 0.004) than high-density group. Conclusion In our study, the anchor density was not related to coronal or axial curve corrections. Mild positive correlations with anchor density were found in thoracic kyphosis correction, especially in patients with smaller and flexible curves. Low anchor density with longer fusion level achieves similar curve corrections with middle or high anchor density in adolescent idiopathic scoliosis surgery.

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How Sublaminar Bands Affect Postoperative Sagittal Alignment in AIS Patients with Preoperative Hypokyphosis? Results of a Series of 34 Patients with 2-Year Follow-Up

BioMed Research International ◽

10.1155/2016/1954712 ◽

2016 ◽

Vol 2016 ◽

pp. 1-5 ◽

Cited By ~ 4

Author(s):

Sébastien Pesenti ◽

Antoine Chalopin ◽

Emilie Peltier ◽

Elie Choufani ◽

Matthieu Ollivier ◽

...

Keyword(s):

Idiopathic Scoliosis ◽

Cobb Angle ◽

Lumbar Lordosis ◽

Thoracic Kyphosis ◽

Radiographic Evaluation ◽

Cervical Lordosis ◽

Pelvic Parameters ◽

Sublaminar Bands ◽

Thoracic Idiopathic Scoliosis

Hypokyphosis is currently observed in thoracic idiopathic scoliosis. The use of sublaminar bands allows a good restoration of sagittal balance of the spine. The aim of the study was to provide a middle-term radiographic analysis of patients with adolescent idiopathic scoliosis with preoperative hypokyphosis treated by posterior arthrodesis with sublaminar bands. This retrospective study included 34 patients with Lenke 1 scoliosis associated with hypokyphosis (TK < 20°). A radiographic evaluation was performed with a 2-year follow-up. Cobb angle, cervical lordosis, thoracic kyphosis, lumbar lordosis, and pelvic parameters were measured preoperatively, postoperatively, and at 6-month and 2-year follow-up. The mean preoperative thoracic kyphosis was 10.5° versus 24.1° postoperatively (p<0.001), representing a mean gain of 13°. Cobb angle ranged from 59.3° to 17.9° postoperatively (mean correction 69%,p<0.001). Cobb angle increased between the immediate postoperative measurement and the 6-month follow-up (17.9 versus 19.9,p=0.03). Cervical curvature changed from a 5.6° kyphosis to a 3.5° lordosis (p=0.001). Concerning lumbar lordosis, preoperative measurement was 39.7° versus 41.3° postoperatively (p=0.27). At 6-month follow-up, lumbar lordosis significantly increased to 43.6° (p=0.03). All parameters were stable at final follow-up. Correction performed by sublaminar bands is efficient for both fontal and sagittal planes. Moreover, the restoration of normal thoracic kyphosis is followed by an adaptation of the adjacent curvatures with improved cervical lordosis and lumbar lordosis.

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Predictability of Coronal Curve Flexibility in Postoperative Curve Correction in Adolescent Idiopathic Scoliosis: The Effect of the Sagittal Profile

Global Spine Journal ◽

10.1177/2192568219877862 ◽

2019 ◽

Vol 10 (3) ◽

pp. 303-311 ◽

Cited By ~ 1

Author(s):

Søren Ohrt-Nissen ◽

Hideki Shigematsu ◽

Jason Pui Yin Cheung ◽

Keith D. K. Luk ◽

Dino Samartzis

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Cobb Angle ◽

Thoracic Kyphosis ◽

Clinical Decision Making ◽

Sagittal Profile ◽

Curve Correction ◽

Sagittal Vertical Axis ◽

Flexibility Index

Study Design: Retrospective cohort study. Objectives: To assess how the thoracic kyphosis affects the ability of the fulcrum bending radiograph (FBR) to predict the coronal thoracic curve correction. Methods: A retrospective study of prospectively collected data was conducted of 107 consecutive patients with thoracic adolescent idiopathic scoliosis (AIS) treated with a standard screw-fixation protocol. Radiographic variables were assessed preoperatively and at 2-year follow-up. Curve flexibility was determined based on the FBR and the Fulcrum Bending Flexibility Index (FBCI). Radiographic variables included preoperative Cobb angle, T5-T12 kyphosis, T12-S1 lordosis, sagittal vertical axis, list, T1-T12 length, truncal shift, and radiographic shoulder height. Patients were also categorized as hypo-, normo-, or hyperkyphotic. Results: Based on multivariate modeling, an increase in FBR Cobb angle and thoracic kyphosis were significantly associated with an increase in FBCI (increased mismatch between the FBR and postoperative Cobb angles) at 2-year follow-up ( P < 0.001). In patients with hyperkyphosis, a longer instrumented length existed despite similar curve size and shorter curve length than the hypo- and normokyphotic groups. Based on these findings, we developed a new predictive postoperative curve correction index, known as the Multiprofile Flexibility Index (MFI). Conclusions: Our results show that an increase in preoperative thoracic kyphosis is associated with an increased difference between the preoperative coronal curve flexibility and the postoperative coronal curve correction. Our findings broaden the understanding of curve flexibility and indicate that selection of fusion levels may need to take into consideration the sagittal profile to improve clinical decision making and optimize outcome.

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Higher pedicle screw density does not improve curve correction in Lenke 2 adolescent idiopathic scoliosis

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-021-02415-4 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Timothy J. Skalak ◽

Joel Gagnier ◽

Michelle S. Caird ◽

Frances A. Farley ◽

Ying Li

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Thoracic Kyphosis ◽

Curve Correction ◽

Major Curve ◽

Curve Magnitude ◽

Screw Density ◽

Implant Density ◽

Lenke 2

Abstract Purpose Higher pedicle screw density posterior spinal fusion (PSF) constructs have not been shown to result in improved curve correction in Lenke 1 and 5 adolescent idiopathic scoliosis (AIS) but do increase cost. The purpose of this study questioned whether higher screw density constructs improved curve correction and maintenance of correction in Lenke 2 AIS. Secondary goals were to identify predictive factors for correction and postoperative magnitude of curves in Lenke 2 AIS. Methods We identified patients 11 to 17 years old who underwent primary PSF for Lenke 2 AIS between 2007 and 2017 who had minimum follow-up of 2 years. Demographic and radiographic data were collected to perform regression and elimination analysis. Results Thirty patients (21 females, 9 males) were analyzed. Average age and SD at time of surgery was 14.0 ± 1.8 years (range, 11–17 years), and median follow-up was 2.8 years (IQR 2.1–4.0 years). Implant density did not predict final postoperative curve magnitude. Predictors of final postoperative curve magnitude were sex and preoperative curve magnitude. Predictors of percentage of correction of major curve were sex and age at the time of surgery. Predictors of final postoperative thoracic kyphosis were sex and percent flexibility preop. Females had lower final postoperative major curve magnitude, a higher percent curve correction, and lower postoperative thoracic kyphosis. Conclusions Increased implant density is not predictive of postoperative curve magnitude in Lenke 2 AIS. Predictors of postoperative curve magnitude are sex and preoperative curve magnitude. Level of evidence Level III, retrospective observational

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“Higher Pedicle Screw Density Does Not Result in Improved Curve Correction in Lenke 2 Adolescent Idiopathic Scoliosis”

10.21203/rs.3.rs-262745/v1 ◽

2021 ◽

Author(s):

Timothy Skalak ◽

Joel Gagnier ◽

Michelle S. Caird ◽

Frances A. Farley ◽

Ying Li

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Thoracic Kyphosis ◽

Curve Correction ◽

Major Curve ◽

Curve Magnitude ◽

Screw Density ◽

Implant Density ◽

Lenke 2

Abstract Purpose: Higher pedicle screw density posterior spinal fusion (PSF) constructs have not been shown to result in improved curve correction in Lenke 1 and 5 adolescent idiopathic scoliosis (AIS) but do increase cost. The purpose of this study questioned whether higher screw density constructs improved curve correction and maintenance of correction in Lenke 2 AIS. Secondary goals were to identify predictive factors for correction and postoperative magnitude of curves in Lenke 2 AIS. Methods: We identified patients 11 to 17 years old who underwent primary PSF for Lenke 2 AIS between 2007 and 2017 who had minimum follow up of 2 years. Demographic and radiographic data were collected to perform regression and elimination analysis. Results: Thirty patients (21 Female, 9 male) were analyzed. Average age and SD at time of surgery was 14.0 ± 1.8 years (range, 11-17 years) and median follow-up was 2.8 years (IQR 2.1-4.0 years). Implant density did not predict final postoperative curve magnitude. Predictors of final postoperative curve magnitude were sex and preoperative curve magnitude. Predictors of percentage of correction of major curve were sex and age at the time of surgery. Predictors of final postoperative thoracic kyphosis were sex and percent flexibility preop. Females had lower final postoperative major curve magnitude, a higher percent curve correction, and lower postoperative thoracic kyphosis.Conclusions: Increased implant density is not predictive of postoperative curve magnitude in Lenke 2 AIS. Predictors of postoperative curve magnitude are sex and preoperative curve magnitude.Level of Evidence: Level III Retrospective Observational

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More severe thoracic idiopathic scoliosis is associated with a greater three-dimensional loss of thoracic kyphosis

Spine Deformity ◽

10.1007/s43390-020-00149-7 ◽

2020 ◽

Vol 8 (6) ◽

pp. 1205-1211

Author(s):

Thomas Barrett Sullivan ◽

Tracey P. Bastrom ◽

Carrie E. Bartley ◽

Lori A. Dolan ◽

Stuart L. Weinstein ◽

...

Keyword(s):

Idiopathic Scoliosis ◽

Thoracic Kyphosis ◽

Three Dimensional ◽

Thoracic Idiopathic Scoliosis

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Improved restoration of thoracic kyphosis using a rod construct with differentiated rigidity in the surgical treatment of adolescent idiopathic scoliosis

Neurosurgical FOCUS ◽

10.3171/2017.7.focus17351 ◽

2017 ◽

Vol 43 (4) ◽

pp. E6 ◽

Cited By ~ 3

Author(s):

Søren Ohrt-Nissen ◽

Casper Dragsted ◽

Benny Dahl ◽

John A. I. Ferguson ◽

Martin Gehrchen

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Thoracic Kyphosis ◽

Sagittal Alignment ◽

Group Versus ◽

Secondary Outcome ◽

Curve Correction ◽

Caudal Portion ◽

Significant Difference ◽

The Mean

OBJECTIVEThe objective of this study was to compare postoperative sagittal alignment among 3 rod constructs with different rigidity profiles.METHODSThis was a dual-center retrospective cohort study involving 2 consecutive cohorts in which patients were surgically treated for adolescent idiopathic scoliosis. Lenke Type 5 curves were excluded. Patients were operated on with all–pedicle screw instrumentation using 3 different rod constructs. The first group was operated on using a hybrid construct (HC) consisting of a normal circular rod on the convex side and a beam-like rod (BR) on the concave side. The second group was operated on with a standard construct (SC) using bilateral BRs in the full length of the fusion. The third group was operated on with a modified construct (MC). The modified rods have a beam-like shape in the caudal portion, but in the cranial 2 or 3 fusion levels the rod transitions to a circular shape with a smaller anteroposterior diameter. Radiographs were analyzed preoperatively and at the first postoperative follow-up (range 1–8 weeks). The primary outcome was pre- to postoperative change in thoracic kyphosis (TK), and the secondary outcome was the ability to achieve postoperative TK within the normal range.RESULTSThe HC, SC, and MC groups included 23, 70, and 46 patients, respectively. The 3 groups did not differ significantly in preoperative demographic or radiographic parameters. The mean ± standard deviation of the preoperative main curve was 60.7° ± 12.6°, and the mean of curve correction was 62.9% ± 10.4% with no significant difference among groups (p ≥ 0.680). The groups did not differ significantly in coronal balance or proximal or thoracolumbar curve correction (p ≥ 0.189). Mean postoperative TK was 23.1° ± 6.3°, 19.6° ± 7.6°, and 23.4° ± 6.9° in the HC, SC and MC groups, respectively (p = 0.013), and the mean change in TK was −3.5° ± 11.3°, −7.1° ± 11.6°, and 0.1° ± 10.9°, respectively (p = 0.005). The MC group had significantly higher postoperative TK and less loss of TK compared with the SC group (p ≤ 0.018). Postoperative TK ≤ 10° was found in 12 patients (17%) in the SC group, 1 patient (5%) in the HC group, and 1 patient (2%) in the MC group (p = 0.021). There were no differences in proximal alignment, thoracolumbar alignment, or sagittal vertical axis (p ≥ 0.249). Lumbar lordosis was 58.9° ± 11.2° in the HC group versus 52.0° ± 1.3° and 55.0° ± 11.0° and the SC and MC groups, respectively (p = 0.040).CONCLUSIONSIn the 3 rod constructs with different rigidity profiles, significantly better restoration of kyphosis was achieved with the use of bilateral modified rods compared with bilateral standard rods. In the MC and HC groups, the rate of severe postoperative hypokyphosis was significantly lower than in the SC group. This is the first study to describe the clinical use of a rod with a reduced proximal diameter and show marked radiographic improvement in sagittal alignment.

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Minimally Invasive Scoliosis Surgery Is a Feasible Option for Management of Idiopathic Scoliosis and Has Equivalent Outcomes to Open Surgery: A Meta-Analysis

Global Spine Journal ◽

10.1177/2192568220988267 ◽

2021 ◽

pp. 219256822098826

Author(s):

Abduljabbar Alhammoud ◽

Yahya Alborno ◽

Abdul Moeen Baco ◽

Yahya Azhar Othman ◽

Yoji Ogura ◽

...

Keyword(s):

Postoperative Pain ◽

Blood Loss ◽

Minimally Invasive ◽

Idiopathic Scoliosis ◽

Operative Time ◽

Meta Analysis ◽

Scoliosis Surgery ◽

Curve Correction ◽

Estimated Blood Loss ◽

Feasible Option

Study Design: Meta-analysis. Objective: To compare outcomes between minimally invasive scoliosis surgery (MISS) and traditional posterior instrumentation and fusion in the correction of adolescent idiopathic scoliosis (AIS). Methods: A literature search was performed using MEDLINE, PubMed, EMBASE, Google scholar and Cochrane databases, including studies reporting outcomes for both MISS and open correction of AIS. Study details, demographics, and outcomes, including curve correction, estimated blood loss (EBL), operative time, postoperative pain, length of stay (LOS), and complications, were collected and analyzed. Results: A total of 4 studies met the selection criteria and were included in the analysis, totaling 107 patients (42 MIS and 65 open) with a mean age of 16 years. Overall there was no difference in curve correction between MISS (73.2%) and open (76.7%) cohorts. EBL was significantly lower in the MISS (271 ml) compared to the open (527 ml) group, but operative time was significantly longer (380 min for MISS versus 302 min for open). There were no significant differences between the approaches in pain, LOS, complications, or reoperations. Conclusion: MISS was associated with less blood loss but longer operative times compared to traditional open fusion for AIS. There was no difference in curve correction, postoperative pain, LOS, or complications/reoperations. While MISS has emerged as a feasible option for the surgical management of AIS, further research is warranted to compare these 2 approaches.

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