Concave or convex rod translation first in adolescent idiopathic scoliosis instrumentation with differential rod contouring?

2021 ◽  
Author(s):  
X Wang ◽  
CE Aubin ◽  
RM Schwend
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Thoracic Kyphosis ◽  
Deformity Correction ◽  
Vertebral Rotation ◽  
Convex Side ◽  
Bone Screw ◽  
Apical Vertebral Rotation ◽  
Clinically Significant

The objective was to assess deformity correction and bone-screw force associated respectively with concave manipulation first, convex manipulation first, and different differential rod contouring configurations. Instrumentation scenarios were computationally simulated for 10 AIS cases with mean thoracic Cobb angle (MT) of 54±8°, apical vertebral rotation (AVR) of 19±2° and thoracic kyphosis of 21±9°. Instrumentations with major correction maneuvers using the concave side rod were first simulated; instrumentations with major correction maneuvers using the convex side rod were then simulated. Simulated correction maneuvers were concave/convex rod translation followed by apical vertebral derotation and then convex/concave rod translation. There were no significant differences in deformity corrections and bone-screw forces between concave rod translation first and convex rod translation first with differential rod contouring. Increasing differential rod contouring angle and concave rod diameter improved AVR correction and increased the TK and bone-screw forces; the effect on the MT Cobb angle was not clinically significant.

scholarly journals Sagittal profile modifications in hybrid versus all screw technique in adolescent idiopathic scoliosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Laura Scaramuzzo ◽  
Antonino Zagra ◽  
Giuseppe Barone ◽  
Stefano Muzzi ◽  
Leone Minoia ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Thoracic Kyphosis ◽  
Sagittal Alignment ◽  
Vertical Axis ◽  
Sagittal Profile ◽  
Sacral Slope ◽  
Sagittal Vertical Axis ◽  
Lenke Classification

AbstractAim of the study was to evaluate sagittal parameters modifications, with particular interest in thoracic kyphosis, in patients affected by adolescent idiopathic scoliosis (AIS) comparing hybrid and all-screws technique. From June 2010 to September 2018, 145 patients were enrolled. Evaluation included: Lenke classification, Risser scale, coronal Cobb angle, thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS). Patients were divided in two groups (1 all-screws and 2 hybrid); a further division, in both groups, was done considering preoperative TK values. Descriptive and inferential statistical analysis was conducted. 99 patients were in group 1, 46 in group 2 (mean follow-up 3.7 years). Patients with a normo-kyphotic profile developed a little variation in TK (Δ pre–post = 2.4° versus − 2.0° respectively). Hyper-kyphotic subgroups had a tendency of restoring a good sagittal alignment. Hypo-kyphotic subgroups, patients treated with all-screw implants developed a higher increase in TK mean Cobb angle (Δ pre–post = 10°) than the hybrid subgroup (Δ pre–post = 5.4°) (p = 0.01). All-screws group showed better results in restoring sagittal alignment in all subgroups compared to hybrid groups, especially in hypo-TK subgroup, with the important advantage to give better correction on coronal plane.

scholarly journals Is There a Correlation between the Apical Vertebral Rotation and the Pelvic Incidence in Adolescent Idiopathic Scoliosis?

2016 ◽  
Vol 6 (1_suppl) ◽  
pp. s-0036-1583044-s-0036-1583044
Author(s):  
Khalil Kharrat ◽  
Amer Sebaaly ◽  
Ayman Assi ◽  
Ismat Ghanem ◽  
Rami Rachkidi
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Pelvic Incidence ◽  
Vertebral Rotation ◽  
Apical Vertebral Rotation

scholarly journals Uniplanar cannulated pedicle screws in the correction of Lenke type 1 adolescent idiopathic scoliosis (AIS)

2020 ◽  
Author(s):  
Yiwei Zhao ◽  
Wubo Liu ◽  
Suomao Yuan ◽  
Yonghao Tian ◽  
Xinyu Liu
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Pedicle Screws ◽  
Vertebral Rotation ◽  
Concave Side ◽  
Convex Side ◽  
X Rays ◽  
Group A ◽  
Group B

Abstract Background In the present study, we reported the clinical use of uniplanar cannulated pedicle screws for the correction of Lenke type 1 adolescent Idiopathic scoliosis (AIS), and its safety and clinical outcomes were also evaluated. Methods 68 patients with Lenke type 1 AIS were included, among which 38 patients were treated with uniplanar cannulated screws at the concave side of periapical levels and multiaxial screws at the other levels (group A). Moreover, the remaining 30 patients were treated with all multiaxial screws (group B). The preoperative and postoperative radiographic parameters of the Lenke type 1 AIS, axial vertebral rotation, and the safety of the pedicle screws were evaluated by X-rays and computed tomography (CT). Results Preoperative data was comparable between two groups. The postoperative proximal thoracic (PT) curve, main thoracic (MT) curve, thoracolumbar/lumbar (TL/L) curve, and apical vertebral rotation were significantly improved compared with the preoperative data. The coronal correction rates in group A and B were 83% and 81.9%, respectively (P > 0.05). The derotation rates in group A and B were 60.8% and 43.2%, respectively (P < 0.05). The rotation classification in the group A was also better compared with the group B. The misplacement rate in group A and B was 7.9% and 11.8%, respectively (P < 0.05), and the total misplacement rate on the concave side (11.4%) was higher than that of convex side (8.4%). The lateral perforation was found at the concave side, while the medial perforation was found at the convex side. On the concave side, the misplacement rate in group A and B was 9.7% and 12.3%, respectively (P < 0.05). The grades 2 and 3 perforations were three (3.5%) in the group A and eight (8.2%) in the group B (P < 0.05). On the convex side, the misplacement rate in group A and B was 5.9% and 11.1%, respectively (P < 0.05). The grades 2 and 3 perforations were one (0.9%) in the group A and four (4.4%) in the group B (P < 0.05). Conclusion Collectively, uniplanar cannulated pedicle screws could effectively increase the accuracy of pedicle screws and facilitate the derotation of the apical vertebra compared with the multiaxial pedicle screws. Trial registration retrospectively registered

scholarly journals Maximal Axial Vertebral Rotation in Adolescent Idiopathic Scoliosis: Is the Apical Vertebra the Most Rotated?

2020 ◽  
pp. 219256822094883
Author(s):  
Kristóf József ◽  
Ádám Tibor Schlégl ◽  
Máté Burkus ◽  
István Márkus ◽  
Ian O’Sullivan ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Axial Rotation ◽  
Cross Sectional Study ◽  
Vertebral Rotation ◽  
Rank Test ◽  
Cross Sectional ◽  
Apical Vertebra ◽  
Axial Vertebral Rotation

Study Design: Retrospective cross-sectional study. Objectives: It is generally believed that the apical vertebra has the largest axial rotation in adolescent idiopathic scoliosis. We investigated the relationship between apical axial vertebral rotation (apicalAVR) and maximal axial vertebral rotation (maxAVR) in both major and minor curves using biplanar stereo-imaging. Methods: EOS 2D/3D biplanar radiograph images were collected from 332 patients with adolescent idiopathic scoliosis (Cobb angle range 10°-122°, mean age 14.7 years). Based on the X-ray images, with the help of 3D full spine reconstructions Cobb angle, curvature level, apicalAVR and maxAVR were determined. These parameters were also determined for minor curves in Lenke 2, 3, 4, 6 type patients. Maximal thoracic rotation and maximal thoracolumbar/lumbar rotation were calculated. Statistical analysis was performed with descriptive statistics, Shapiro-Wilk test, and Wilcoxon signed-rank test. Results: The apical vertebrae were the most rotated vertebra in only 40.4% of the major curves, and 31.7% in minor curves. MaxAVR significantly exceeded apicalAVR values in the major curves ( P < .001) as well as in minor curves ( P < .001). The 2 parameters differed significantly in each severity group and Lenke type. Conclusions: The apical vertebrae were not the most rotated vertebra in more than half of cases investigated indicating that apicalAVR and maxAVR should be considered as 2 distinct parameters, of which maxAVR fully describes the axial dimension of scoliosis. Furthermore, the substitution of maxAVR for the apicalAVR should be especially avoided in double and triple curves, as the apical vertebra was even less commonly the most rotated in minor curves.

scholarly journals Fixed lumbar apical vertebral rotation predicts spinal decompensation in lenke type 3c adolescent idiopathic scoliosis after selective posterior thoracic correction and fusion

2007 ◽  
Vol 16 (10) ◽  
pp. 1570-1578 ◽  
Author(s):  
Hannes Behensky ◽  
Ashley A. Cole ◽  
Brian J. C. Freeman ◽  
Michael P. Grevitt ◽  
Hossein S. Mehdian ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Vertebral Rotation ◽  
Apical Vertebral Rotation

scholarly journals Is the apical vertebra the most rotated vertebra in the scoliotic curve?

2019 ◽  
Vol 31 (6) ◽  
pp. 873-879
Author(s):  
Chris Labaki ◽  
Joeffroy Otayek ◽  
Abir Massaad ◽  
Ziad Bakouny ◽  
Mohammad Karam ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Significant Proportion ◽  
Vertebral Rotation ◽  
Scoliotic Curve ◽  
3D Reconstructions ◽  
Apical Vertebra ◽  
Multinomial Models ◽  
Apical Vertebral Rotation ◽  
The Difference

OBJECTIVEThe aim of this study was to determine if the apical vertebra (AV) in patients with adolescent idiopathic scoliosis (AIS) is the most rotated vertebra in the scoliotic segment.METHODSA total of 158 patients with AIS (Cobb angle range 20°–101°) underwent biplanar radiography with 3D reconstructions of the spine and calculation of vertebral axial rotations. The type of major curvature was recorded (thoracic, thoracolumbar, or lumbar), and both major and minor curvatures were included. The difference of levels (DL) between the level of maximal vertebral rotation (LMVR) and the AV was calculated as follows: DL = 0 if LMVR and AV were the same, DL = 1 if LMVR was directly above or below the AV, and DL = 2 if LMVR was separated by 1 vertebra or more from the AV. To investigate which factors explained the divergence of the LMVR from the AV, multinomial models were computed.RESULTSThe distribution of the DL was as follows: for major curvatures, 143 were DL = 0, 11 were DL = 1, and 4 were DL = 2; and for minor curvatures, 53 were DL = 0, 9 were DL = 1, and 31 were DL = 2. The determinants of a DL = 2 (compared with DL = 0) were lumbar curvature (compared with thoracic; adjusted OR 0.094, p = 0.001), major curvature (compared with minor; adjusted OR 0.116, p = 0.001), and curvatures with increasing apical vertebral rotation (adjusted OR 0.788, p < 0.001).CONCLUSIONSThis study showed that the AV is the most rotated vertebra in the majority of major curvatures, while in minor curvatures, the most rotated vertebra appears to be the junctional vertebra between major and minor curvatures in a significant proportion of cases.

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

2019 ◽  
Vol 10 (3) ◽  
pp. 303-311 ◽  
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.

The effect of direct vertebral rotation on the spine parameters (coronal and sagittal) in adolescent idiopathic scoliosis

2021 ◽  
pp. 1-8
Author(s):  
Carlos Eduardo Gonçales Barsotti ◽  
Carlos Augusto Belchior B. Junior ◽  
Rodrigo Mantelatto Andrade ◽  
Alexandre Penna Torini ◽  
Ana Paula Ribeiro
Keyword(s):  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Lumbar Lordosis ◽  
Thoracic Kyphosis ◽  
Pelvic Tilt ◽  
Pelvic Incidence ◽  
Vertebral Rotation ◽  
Sacral Slope ◽  
Post Surgery ◽  
Radiographic Parameters

BACKGROUND: Idiopathic scoliosis is accompanied by postural alterations, instability of gait, and functional disabilities. The objective was to verify radiographic parameters (coronal and sagittal) of adolescents with idiopathic scoliosis (AIS) pre- and post-surgery with direct vertebral rotation (DVR), associated with type 1 osteotomies in all segments (except the most proximal) and type 2 in the periapical vertebrae of the curves. METHODS: A prospective study design was employed in which 41 AIS were evaluated and compared pre- and post-surgery. Scoliosis was confirmed by a spine X-ray exam (Cobb angle). Eight radiographic parameters were measured: Cobb angles (thoracic proximal and distal), segmental kyphosis, total kyphosis, lumbar lordosis, pelvic incidence, sacral slope, and pelvic tilt. RESULTS: The Cobb angle averaged 51.3∘± 14.9∘. Post-surgery, there were significant reductions for the following spine measurement parameters: Cobb angle thoracic proximal (p= 0.003); Cobb angle thoracic distal (p= 0.001); Cobb angle lumbar (p= 0.001); kyphosis (T5-T12, p= 0.012); and kyphosis (T1-T12, p= 0.002). These reductions showed the effectiveness of surgical correction to reduce Cobb angles and improve thoracic kyphosis. The values obtained for lumbar lordosis, pelvic incidence, sacral slope, and pelvic tilt were not significantly different pre- and post-surgery. CONCLUSION: The surgical technique of DVR in AIS proved to be effective in the coronal and sagittal parameters directed at Cobb angles and thoracic kyphosis in order to favor the rehabilitation process.

scholarly journals Alternate In-Brace and Out-of-Brace Radiographs Are Recommended to Assess Brace Fitting and Curve Progression With Adolescent Idiopathic Scoliosis Follow-Up

2021 ◽  
pp. 219256822110325
Author(s):  
Sachiko Kawasaki ◽  
Prudence Wing Hang Cheung ◽  
Hideki Shigematsu ◽  
Masato Tanaka ◽  
Yuma Suga ◽  
...  
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Cobb Angle ◽  
Curve Progression ◽  
Brace Treatment ◽  
Correction Rate ◽  
Angle Correction ◽  
Clinically Significant ◽  
Deterioration Group

Study Design: Retrospective cohort study. Objective: To determine the prevalence of missed curve progression in patients with adolescent idiopathic scoliosis (AIS) undergoing brace treatment with only in-brace follow-up radiographs, and to provide recommendations on when in-brace and out-of-brace should be obtained during follow-up. Methods: 133 patients who had documented clinically significant curve progression during brace treatment or only when an out-of-brace radiograph were studied. Of these, 95 patients (71.4%) had curve progression noted on in-brace radiographs while 38 patients (28.6%) showed curve progression only after brace removal. We analyzed differences in age, sex, curve types, Risser stage, months after menarche, standing out-of-brace Cobb angle, correction rate, and flexibility rate between the groups. Multivariate logistic regression was performed to determine factors contributing to curve progression missed during brace treatment. Results: There were no differences in initial Cobb angle between out-of-brace and in-brace deterioration groups. However, the correction rate was higher (32.7% vs 25.0%; P = .004) in the in-brace deterioration group as compared to the out-of-brace deterioration group. A lower correction rate was more likely to result in out-of-brace deterioration (OR 0.970; P = .019). For thoracic curves, higher flexibility in the curves was more likely to result in out-of-brace deterioration (OR 1.055; P = .045). For double/triple curves, patients with in-brace deterioration had higher correction rate (OR 0.944; P = .034). Conclusions: Patients may develop curve progression despite good correction on in-brace radiographs. Those with higher flexibility and suboptimal brace fitting are at-risk. In-brace and out-of-brace radiographs should be taken alternately for brace treatment follow-up.

Sign in / Sign up

Export Citation Format

Share Document