scholarly journals The effects of vertebral body tethering on sagittal parameters: evaluations from a 2-years follow-up

Author(s):  
Alice Baroncini ◽  
Aurelien Courvoisier ◽  
Pedro Berjano ◽  
Filippo Migliorini ◽  
Jörg Eschweiler ◽  
...  

Abstract Introduction While the effects of VBT on coronal parameters have been investigated in various studies, this has not yet been the case for sagittal parameters. This is of particular relevance considering that VBT does not allow direct correction of the sagittal profile. Thus, we investigated the effects of VBT on sagittal parameters in patients with adolescent idiopathic scoliosis. Materials and methods Retrospective, 2-Center study. Patients who underwent VBT and presented a 2-years follow-up were included. The differences in sagittal parameters were evaluated, along with modifications of sagittal profile following Abelin-Genevois’ classification. Results Data from 86 patients were obtained. Mean Cobb angle was 52.4 ± 13.9° at thoracic level and 47.6 ± 14.3° at lumbar level before surgery, and 28.5 ± 13.6 and 26.6 ± 12.7° at the 2-year follow-up, respectively. Mean thoracic kyphosis increased from 28.3 ± 13.8 to 33 ± 13°, the lumbar lordosis (LL) was unvaried (from 47.5 ± 13.1 to 48.4 ± 13.5°), PT decreased from 9.4 ± 8.5 to 7.4 ± 6.1°, the sagittal vertical axis SVA decreased from 4.5 ± 31.4 to − 3.6 ± 27.9 mm. No kyphotic effect on LL in patients who underwent lumbar instrumentation was observed. Before surgery, 39 patients had a type 1 sagittal profile, 18 were type 2a, 14 type 2b and 15 type 3. Postoperatively, 54 were type 1, 8 were 2a, 13 were 2b and 11 were type 3. Conclusions VBT positively influences sagittal parameters and does not have a kyphotic effect on LL.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Laura Scaramuzzo ◽  
Antonino Zagra ◽  
Giuseppe Barone ◽  
Stefano Muzzi ◽  
Leone Minoia ◽  
...  

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.


2017 ◽  
Vol 11 (5) ◽  
pp. 770-779 ◽  
Author(s):  
Subaraman Ramchandran ◽  
Norah Foster ◽  
Akhila Sure ◽  
Thomas J. Errico ◽  
Aaron J. Buckland

<sec><title>Study Design</title><p>Retrospective analysis.</p></sec><sec><title>Purpose</title><p>Our hypothesis is that the surgical correction of adolescent idiopathic scoliosis (AIS) maintains normal sagittal alignment as compared to age-matched normative adolescent population.</p></sec><sec><title>Overview of Literature</title><p>Sagittal spino-pelvic alignment in AIS has been reported, however, whether corrective spinal fusion surgery re-establishes normal alignment remains unverified.</p></sec><sec><title>Methods</title><p>Sagittal profiles and spino-pelvic parameters of thirty-eight postsurgical correction AIS patients ≤21 years old without prior fusion from a single institution database were compared to previously published normative age-matched data. Coronal and sagittal measurements including structural coronal Cobb angle, pelvic incidence, pelvic tilt, thoracic kyphosis, lumbar lordosis, sagittal vertical axis, C2–C7 cervical lordosis, C2–C7 sagittal vertical axis, and T1 pelvic angles were measured on standing full-body stereoradiographs using validated software to compare preoperative and 6 months postoperative changes with previously published adolescent norms. A sub-group analysis of patients with type 1 Lenke curves was performed comparing preoperative to postoperative alignment and also comparing this with previously published normative values.</p></sec><sec><title>Results</title><p>The mean coronal curve of the 38 AIS patients (mean age, 16±2.2 years; 76.3% female) was corrected from 53.6° to 9.6° (80.9%, <italic>p</italic>&lt;0.01). None of the thoracic and spino-pelvic sagittal parameters changed significantly after surgery in previously hypo- and normo-kyphotic patients. In hyper-kyphotic patients, thoracic kyphosis decreased (<italic>p</italic>=0.003) with a reciprocal decrease in lumbar lordosis (<italic>p</italic>=0.01), thus lowering pelvic incidence-lumbar lordosis mismatch mismatch (<italic>p</italic>=0.009). Structural thoracic scoliosis patients had slightly more thoracic kyphosis than age-matched patients at baseline and surgical correction of the coronal plane of their scoliosis preserved normal sagittal alignment postoperatively. A sub-analysis of Lenke curve type 1 patients (n=24) demonstrated no statistically significant changes in the sagittal alignment postoperatively despite adequate coronal correction.</p></sec><sec><title>Conclusions</title><p>Surgical correction of the coronal plane in AIS patients preserves sagittal and spino-pelvic alignment as compared to age-matched asymptomatic adolescents.</p></sec>


2019 ◽  
Vol 10 (3) ◽  
pp. 303-311 ◽  
Author(s):  
Søren Ohrt-Nissen ◽  
Hideki Shigematsu ◽  
Jason Pui Yin Cheung ◽  
Keith D. K. Luk ◽  
Dino Samartzis

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.


2017 ◽  
Vol 20 (6) ◽  
pp. 561-566 ◽  
Author(s):  
Zhonghui Chen ◽  
Song Li ◽  
Yong Qiu ◽  
Zezhang Zhu ◽  
Xi Chen ◽  
...  

OBJECTIVEAlthough the vertical expandable prosthetic titanium rib (VEPTR) and growing rod instrumentation (GRI) encourage spinal growth via regular lengthening, they can create different results because of their different fixation patterns and mechanisms in correcting scoliosis. Previous studies have focused comparisons on coronal plane deformity with minimal attention to the sagittal profile. In this retrospective study, the authors aimed to compare the evolution of the sagittal spinal profile in early-onset scoliosis (EOS) treated with VEPTR versus GRI.METHODSThe data for 11 patients with VEPTR and 22 with GRI were reviewed. All patients had more than 2 years’ follow-up with more than 2 lengthening procedures. Radiographic measurements were performed before and after the index surgery and at the latest follow-up. The complications in both groups were recorded.RESULTSPatients in both groups had similar diagnoses, age at the index surgery, and number of lengthening procedures. The changes in the major coronal Cobb angle and T1–S1 spinal height were not significantly different between the 2 groups. Compared with the GRI group, the VEPTR group had less correction in thoracic kyphosis (23% ± 12% vs 44% ± 16%, p < 0.001) after the index surgery and experienced a greater correction loss in thoracic kyphosis (46% ± 18% vs 11% ± 8%, p < 0.001) at the latest follow-up. Although the increase in the proximal junctional angle was not significantly different (VEPTR: 7° ± 4° vs GRI: 8° ± 5°, p = 0.569), the incidence of proximal junctional kyphosis was relatively lower in the VEPTR group (VEPTR: 18.2% vs GRI: 22.7%). No significant changes in the spinopelvic parameters were observed, while the sagittal vertical axis showed a tendency toward a neutral position in both groups. The overall complication rate was higher in the VEPTR group than in the GRI group (72.7% vs 54.5%).CONCLUSIONSThe VEPTR had coronal correction and spinal growth results similar to those with GRI. In the sagittal plane, however, the VEPTR was not comparable to the GRI in controlling thoracic kyphosis. Thus, for hyperkyphotic EOS patients, GRI is recommended over VEPTR.


2018 ◽  
Vol 8 (7) ◽  
pp. 668-675
Author(s):  
Toshiyuki Nakazawa ◽  
Gen Inoue ◽  
Takayuki Imura ◽  
Masayuki Miyagi ◽  
Wataru Saito ◽  
...  

Study Design: Retrospective. Objectives: To evaluate the efficacy of S2 alar screws in surgery for correction of adult spinal deformity (ASD). Methods: We retrospectively reviewed the cases of 23 patients (mean follow-up: 18.5 months, minimum 12 months) who underwent corrective surgery for ASD using S2 alar screws as anchors for instrumentation of lower vertebrae. The background of the patients and their spinopelvic parameters (pelvic incidence [PI], pelvic tilt [PT], lumbar lordosis [LL], thoracic kyphosis [TK], sagittal vertical axis [SVA], and PI-LL) were evaluated. Results: LL was improved from 9.7 ± 20.5° and SVA from 141.0 ± 64.0 mm before surgery to 39.0 ± 9.6° and 51.7 ± 40.8 mm immediately after surgery, respectively, and 38.2 ± 12.7° and 70.5 ± 59.2 mm at final follow-up. In 13 patients without sufficient correction (postoperative PI-LL ≥10°), bone mineral density and postoperative LL were significantly less, and PI, PI-LL, and PT were significantly greater than in patients with postoperative PI-LL <10°, suggesting that these are risk factors for undercorrection. In 5 patients, SVA increased more than 40 mm during follow-up. Postoperative LL was significantly less (31.4° vs 41.0°) and postoperative PI-LL was significantly greater (21.6° vs 9.3°) in these patients, suggesting a PI-LL mismatch induces postoperative progression of global malalignment. Conclusions: Use of S2 alar screws as anchors for instrumentation in ASD surgery should be restricted. Their use might be an option for patients with low PI, and without severe osteoporosis, in whom efficient surgical correction can be obtained.


2021 ◽  
pp. 219256822198964
Author(s):  
Siyu Zhou ◽  
Zhuoran Sun ◽  
Wei Li ◽  
Da Zou ◽  
Weishi Li

Study Design: Cross-sectional study. Objective: To provide the age- and pelvic incidence-related variations of sagittal alignment in asymptomatic Chinese population. Methods: This study recruited asymptomatic adult subjects. All subjects undertook the standing whole spinal radiograph and the sagittal parameters were measured: sagittal vertical axis (SVA), T1 pelvic angle (TPA), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic incidence (PI) and pelvic tilt (PT). All subjects were divided into young, middle aged and elderly groups, then each age group was further divided into 5 subgroups (very low, low, average, high and very high) based on PI values. The relations between PI, age and other parameters were evaluated. The differences in sagittal parameters of each PI subgroup were compared. Results: 546 subjects were included with an average age of 38.6 years (18 to 81). The number of subjects over 70 years and with very low PI was relatively small. The average of PI, TPA, PT and LL were 45.9° ± 8.4°, 6.4° ± 6.2°, 11.9° ± 6.6° and 49.2° ± 10.1°, respectively. SVA, TPA, TK and PT increased with age ( P < 0.05), while SVA, TPA, PT, PI-LL also increased with PI ( P < 0.05). LL, PT, TPA, PI-LL and LL-TK were different among the 5 PI subgroups ( P < 0.05). However, the values of LL in elderly subjects with high and very high PI were similar. Conclusion: The age- and PI-related variations in sagittal alignment of Chinese population were provided. The sagittal parameters were significantly influenced by age and PI. The individual pelvic morphology should be carefully considered during the assessment and restoration of sagittal balance.


2021 ◽  
pp. 219256822110325
Author(s):  
Athan G. Zavras ◽  
T. Barrett Sullivan ◽  
Navya Dandu ◽  
Howard S. An ◽  
Christopher J. DeWald ◽  
...  

Study Design: Retrospective cohort study. Objectives: The current evidence regarding how level of lumbar pedicle subtraction osteotomy (PSO) influences correction of sagittal alignment is limited. This study sought to investigate the relationship of lumbar level and segmental angular change (SAC) of PSO with the magnitude of global sagittal alignment correction. Methods: This study retrospectively evaluated 53 consecutive patients with adult spinal deformity who underwent lumbar PSO at a single institution. Radiographs were evaluated to quantify the effect of PSO on lumbar lordosis (LL), thoracic kyphosis (TK), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), T1-spinopelvic inclination (T1SPI), T1-pelvic alignment (TPA), and sagittal vertical axis (SVA). Results: Significant correlations were found between PSO SAC and the postoperative increase in LL ( r = 0.316, P = .021) and PT ( r = 0.352, P = .010), and a decrease in TPA ( r = −0.324, P = .018). PSO level significantly correlated with change in T1SPI ( r = −0.305, P = .026) and SVA ( r = −0.406, P = .002), with more caudal PSO corresponding to a greater correction in sagittal balance. On multivariate analysis, more caudal PSO level independently predicted a greater reduction in T1SPI (β = −3.138, P = .009) and SVA (β = −29.030, P = .001), while larger PSO SAC (β = −0.375, P = .045) and a greater number of fusion levels (β = −1.427, P = .036) predicted a greater reduction in TPA. Conclusion: This study identified a gain of approximately 3 degrees and 3 cm of correction for each level of PSO more caudal to L1. Additionally, a larger PSO SAC predicted greater improvement in TPA. While further investigation of these relationships is warranted, these findings may help guide preoperative PSO level selection.


2021 ◽  
pp. bjophthalmol-2021-318820
Author(s):  
Riccardo Sacconi ◽  
Maria Brambati ◽  
Alexandra Miere ◽  
Eliana Costanzo ◽  
Vittorio Capuano ◽  
...  

AimTo characterise macular neovascularisation (MNV) developing in eyes affected by geographic atrophy (GA).MethodsIn this multicentric longitudinal study involving three retina referral centres, patients previously affected by GA who developed an active MNV were included. Patients were investigated using structural optical coherence tomography (OCT), fundus autofluorescence, OCT-angiography and dye angiographies. Patients were treated with ProReNata antivascular endothelial growth factor (VEGF) injections and were revaluated after treatment.ResultsAmong 512 patients previously diagnosed with GA, 40 eyes of 40 patients (mean age 80.8±7.9 years, mean GA area 8.73±7.39 mm2) presented with treatment-naïve exudative MNV (accounting for an estimated prevalence of 7.81%; 5.49 to 10.13, 95% CIs) and thus were included in the analysis. 67.5% of MNVs were classified as type 2 MNV, 25% as type 1, 2.5% as type 3 and 5% as mixed phenotype. In 92.5% of cases, active MNV in GA showed subretinal hyperreflective material with or without evidence of subretinal/intraretinal hyporeflective exudation. During a mean follow-up of 28±25 months, patients were treated with 6.6±6.3 anti-VEGF injections, with 2.9±1.4 injections in the first year of treatment. No patient developed GA enlargement in the area of MNV.ConclusionsMNVs in GA showed different features and therapeutic response in comparison to previously reported features of MNV in age-related macular degeneration (AMD) without GA. For these reasons, the combined phenotype (ie, GA with neovascular AMD) should be considered as a distinct entity in the research and clinical setting.


2020 ◽  
pp. 219256822096075
Author(s):  
Philip K. Louie ◽  
Sravisht Iyer ◽  
Krishn Khanna ◽  
Garrett K. Harada ◽  
Alina Khalid ◽  
...  

Study Design: Retrospective case series. Objective: The purpose of this study is to evaluate the clinical and radiographic outcomes following revision surgery following Harrington rod instrumentation. Methods: Patients who underwent revision surgery with a minimum of 1-year follow-up for flatback syndrome following Harrington rod instrumentation for adolescent idiopathic scoliosis were identified from a multicenter dataset. Baseline demographics and intraoperative information were obtained. Preoperative, initial postoperative, and most recent spinopelvic parameters were compared. Postoperative complications and reoperations were subsequently evaluated. Results: A total of 41 patients met the inclusion criteria with an average follow-up of 27.7 months. Overall, 14 patients (34.1%) underwent a combined anterior-posterior fusion, and 27 (65.9%) underwent an osteotomy for correction. Preoperatively, the most common lower instrumented vertebra (LIV) was at L3 and L4 (61%), whereas 85% had a LIV to the pelvis after revision. The mean preoperative pelvic incidence–lumbar lordosis mismatch and C7 sagittal vertical axis were 23.7° and 89.6 mm. This was corrected to 8.1° and 28.9 mm and maintained to 9.04° and 34.4 mm at latest follow-up. Complications included deep wound infection (12.2%), durotomy (14.6%), implant related failures (14.6%), and temporary neurologic deficits (22.0%). Eight patients underwent further revision surgery at an average of 7.4 months after initial revision. Conclusions: There are multiple surgical techniques to address symptomatic flatback syndrome in patients with previous Harrington rod instrumentation for adolescent idiopathic scoliosis. At an average of 27.7 months follow-up, pelvic incidence–lumbar lordosis mismatch and C7 sagittal vertical axis can be successfully corrected and maintained. However, complication and reoperation rates remain high.


2020 ◽  
Vol 42 (1) ◽  
Author(s):  
Francesca Destro ◽  
Giorgio Selvaggio ◽  
Federica Marinoni ◽  
Andrea Pansini ◽  
Giovanna Riccipetitoni

Primary Obstructive Megaureter (POM) is a common cause of hydronephrosis in children with spontaneous resolution in most cases. High-Pressure Balloon Dilatation (HPBD) has been proposed as a minimally invasive procedure for POM correction in selected patients. The aim of the paper is to review our experience with HPBD in patients with POM. We performed a retrospective study in a single Centre collecting data on patients’ demographics, diagnostic modalities, surgical details, results and follow-up. In particular, the endoscopic aspect of the orifice permitted the identification of 3 patterns: adynamic ureteral segment, stenotic ureteric ring and pseudoureterocelic orifice. We performed HPBD in 30 patients over 6 years. We had 23 patients with adynamic distal ureteral segment (type 1), 4 with stenotic ring (type 2) and 3 with ureterocelic orifice (type 3). In 3 patients (10%) the guidewire did not easily pass into the ureter requiring ureteral stenting or papillotomy. Post-operative course was uneventful. Five patients (3 pseudoureterocelic) required open surgery during follow-up. HPBD for the treatment of POM is a safe and feasible procedure and it can be a definitive treatment of POM. Complications are mainly due to double J stent and none of our patients had symptoms related to vescico-ureteral reflux. The aspect of the orifice, identified during cystoscopy, seems to correlate with the efficacy of the dilatation: type 1 and 2 are associated with good and excellent results respectively; type 3 do not permit dilatation in almost all cases requiring papillotomy. HPBD can be performed in selected patients of all paediatric ages as first therapeutic line. The presence of a pseudoureterocelic orifice or long stenosis might interfere with the ureteral stenting and seems associated with worse outcomes.


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