scholarly journals Implant Distribution Versus Implant Density in Lenke Type 1 Adolescent Idiopathic Scoliosis: Does the Position of the Screw Matter?

2020 ◽  
pp. 219256822094145
Author(s):  
Brian L. Dial ◽  
Valentine R. Esposito ◽  
Anthony A. Catanzano ◽  
Robert D. Fitch ◽  
Robert K. Lark

Study Design: Retrospective study. Objective: Previous studies have demonstrated that increased implant density (ID) results in improved coronal deformity correction. However, low-density constructs with strategically placed fixation points may achieve similar coronal correction. The purpose of this study was to identify key zones along the spinal fusion where high ID statistically correlated to improved coronal deformity correction. Our hypothesis was that high ID within the periapical zone would not be associated with increased percent Cobb correction. Methods: We identified patients with Lenke type 1 curves with a minimum 2-year follow up. The instrumented vertebral levels were divided into 4 zones: (1) cephalad zone, (2) caudal zone, (3) apical zone, and (4) periapical zone. High and low percent Cobb correction groups were compared, high percent Cobb group was defined as percent correction >67%. Total ID, total concave ID, total convex ID, and ID within each zone of the curve were compared between the groups. A multivariable analysis was performed to identify independent predictors for coronal correction. Subsequently increased and decreased thoracic kyphosis (TK) groups were compared, increased TK was defined as post-operative TK being larger than preoperative TK and decreased TK was defined as post-operative TK being less than preoperative TK. Results: The cohort included 68 patients. The high percent Cobb group compared with the low percent Cobb group had significantly greater ID for the entire construct, the total concave side, the total convex side, the apical convex zone, the periapical zone, and the cephalad concave zone. The high percent Cobb group had greater pedicle screw density for the total construct, total convex side, and total concave side. In the multivariate model ID and pedicle screw density remained significant for percent Cobb correction. Ability to achieve coronal balance was not statistically correlated to ID ( P = .78). Conclusions: Increased ID for the entire construct, the entire convex side, the entire concave side, and within each spinal zone was associated with improved percent Cobb correction. The ability to achieve coronal balance was not statistically influence by ID. The results of this study support that increasing ID along the entire length of the construct improves percent Cobb correction.

2020 ◽  
Author(s):  
Yiwei Zhao ◽  
Wubo Liu ◽  
Suomao Yuan ◽  
Yonghao Tian ◽  
Xinyu Liu

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


2017 ◽  
Vol 20 (4) ◽  
pp. 371-377 ◽  
Author(s):  
Yang Li ◽  
Xinxin Yuan ◽  
Shifu Sha ◽  
Zhen Liu ◽  
Weiguo Zhu ◽  
...  

OBJECTIVEThe aim of this study was to investigate how implant density affects radiographic results and clinical outcomes in patients with dystrophic scoliosis secondary to neurofibromatosis Type 1 (NF1).METHODSA total of 41 patients with dystrophic scoliosis secondary to NF1 who underwent 1-stage posterior correction between June 2011 and December 2013 were included. General information about patients was recorded, as were preoperative and postoperative scores from Scoliosis Research Society (SRS)–22 questionnaires. Pearson correlation analysis was used to analyze the associations among implant density, coronal Cobb angle correction rate and correction loss at last follow-up, change of sagittal curve, and apical vertebral translation. Patients were then divided into 2 groups: those with low-density and those with high-density implants. Independent-sample t-tests were used to compare demographic data, radiographic findings, and clinical outcomes before surgery and at last follow-up between the groups.RESULTSSignificant correlations were found between the implant density and the coronal correction rate of the main curve (r = 0.505, p < 0.01) and the coronal correction loss at final follow-up (r = −0.379, p = 0.015). There was no significant correlation between implant density and change of sagittal profile (p = 0.662) or apical vertebral translation (p = 0.062). The SRS-22 scores improved in the appearance, activity, and mental health domains within both groups, but there was no difference between the groups in any of the SRS-22 domains at final follow-up (p > 0.05 for all).CONCLUSIONSAlthough no significant differences between the high- and low-density groups were found in any of the SRS-22 domains at final follow-up, higher implant density was correlated with superior coronal correction and less postoperative correction loss in patients with dystrophic NF1-associated scoliosis.


2018 ◽  
Vol 12 (2) ◽  
pp. 300-308 ◽  
Author(s):  
Srikanth Reddy Dumpa ◽  
Ajoy Prasad Shetty ◽  
Siddharth N. Aiyer ◽  
Rishi Mugesh Kanna ◽  
S Rajasekaran

<sec><title>Study Design</title><p>Retrospective observational study.</p></sec><sec><title>Purpose</title><p>To analyze the effect of low-density (LD) strategic pedicle screw fixation on the correction of coronal and sagittal parameters in adolescent idiopathic scoliosis (AIS) patients.</p></sec><sec><title>Overview of Literature</title><p>LD screw fixation achieves favorable coronal correction, but its effect on sagittal parameters is not well established. AIS is often associated with decreased thoracic kyphosis (TK), and the use of multi-level pedicle screws may result in further flattening of the sagittal profile.</p></sec><sec><title>Methods</title><p>A retrospective analysis was performed on 92 patients with AIS to compare coronal and sagittal parameters preoperatively and at 2-year follow-up. All patients underwent posterior correction via LD strategic pedicle screw fixation. Radiographs were analyzed for primary Cobb angle (PCA), coronal imbalance, cervical sagittal angle (CSA), TK, lumbar lordosis (LL), pelvic incidence, pelvic tilt (PT), sacral slope (SS), C7 plumb line, spino-sacral angle, curve flexibility, and screw density.</p></sec><sec><title>Results</title><p>PCA changed significantly from 57.6°±13.9° to 19°±8.4° (<italic>p</italic> &lt;0.0001) with 67% correction, where the mean curve flexibility was 41% and screw density was 68%. Regional sagittal parameters did not change significantly, including CSA (from 10.76° to 10.56°, <italic>p</italic> =0.893), TK (from 24.4° to 22.8°, <italic>p</italic> =0.145), and LL (from 50.3° to 51.1°, <italic>p</italic> =0.415). However, subgroup analysis of the hypokyphosis group (&lt;10°) and the hyperkyphosis group (&gt;40°) showed significant correction of TK (<italic>p</italic> &lt;0.0001 in both). Sacro-pelvic parameters showed a significant decrease of PT and increase of SS, suggesting a reduction in pelvic retroversion SS (from 37° to 40°, <italic>p</italic> =0.0001) and PT (from 15° to 14°, <italic>p</italic> =0.025).</p></sec><sec><title>Conclusions</title><p>LD strategic pedicle screw fixation provides favorable coronal correction and improves overall sagittal sacro-pelvic parameters. This technique does not cause significant flattening of TK and results in a favorable restoration of TK in patients with hypokyphosis or hyperkyphosis.</p></sec>


Neurosurgery ◽  
2021 ◽  
Author(s):  
Alan H Daniels ◽  
Wesley M Durand ◽  
Renaud Lafage ◽  
Andrew S Zhang ◽  
David K Hamilton ◽  
...  

Abstract BACKGROUND Lateral (ie, coronal) vertebral listhesis may contribute to disability in adult scoliosis patients. OBJECTIVE To assess for a correlation between lateral listhesis and disability among patients with adult scoliosis. METHODS This was a retrospective multi-center analysis of prospectively collected data. Patients eligible for a minimum of 2-yr follow-up and with coronal plane deformity (defined as maximum Cobb angle ≥20º) were included (n = 724). Outcome measures were Oswestry Disability Index (ODI) and leg pain numeric scale rating. Lateral thoracolumbar listhesis was measured as the maximum vertebral listhesis as a percent of the superior endplate across T1-L5 levels. Linear and logistic regression was utilized, as appropriate. Multivariable analyses adjusted for demographics, comorbidities, surgical invasiveness, maximum Cobb angle, and T1-PA. Minimally clinically important difference (MCID) in ODI was defined as 12.8. RESULTS In total, 724 adult patients were assessed. The mean baseline maximum lateral thoracolumbar listhesis was 18.3% (standard deviation 9.7%). The optimal statistical grouping for lateral listhesis was empirically determined to be none/mild (&lt;6.7%), moderate (6.7-15.4%), and severe (≥15.4%). In multivariable analysis, listhesis of moderate and severe vs none/mild was associated with worse baseline ODI (none/mild = 33.7; moderate = 41.6; severe = 43.9; P &lt; .001 for both comparisons) and leg pain NSR (none/mild = 2.9, moderate = 4.0, severe = 5.1, P &lt; .05). Resolution of severe lateral listhesis to none/mild was independently associated with increased likelihood of reaching MCID in ODI at 2 yr postoperatively (odds ratio 2.1 95% confidence interval 1.2–3.7, P = .0097). CONCLUSION Lateral thoracolumbar listhesis is associated with worse baseline disability among adult scoliosis patients. Resolution of severe lateral listhesis following deformity correction was independently associated with increased likelihood of reaching MCID in ODI at 2-yr follow-up.


2021 ◽  
Author(s):  
Shih-Hsiang Chou ◽  
Wen-Wei Li ◽  
Cheng-Chang Lu ◽  
Kun-Ling Lin ◽  
Sung-Yen Lin ◽  
...  

Abstract BackgroundEarly versions of spinal muscular atrophy (SMA) scoliosis correction surgeries often involved sublaminar devices. Recently the utilization of pedicle screw is gaining much popularity. Pedicle screw generally believed to provide additional deformity correction, but pedicle size and rotational deformity limit the application of pedicle screw in the thoracic spine, resulting in a hybrid construct of the pedicle screw and sublaminar wire. Studies of the efficacy of hybrid instrumentation in SMA scoliosis is often limited by the scarcity of the disease itself. In this study, we aimed to compare the surgical outcome of using hybrid constructs of the pedicle screw and sublaminar wire and that of sublaminar wire alone in patients with SMA scoliosis.MethodsWe retrospectively reviewed the clinical records and radiographic assessments of patients with SMA scoliosis who underwent corrective surgery between 1993 and 2015. The radiographic assessments included the deformity correction and the progressive change of major curve angle, pelvic tilt (PT) and coronal balance (CB). The correction of deformities was observed postoperatively and at the patient’s 2-year follow-up to test the efficacy of each type of constructs.ResultsThirty-three patients were included in this study. There were 14 and 19 patients in the wiring and the hybrid construct groups, respectively. The hybrid construct demonstrated a higher major curve angle correction (50.5° ± 11.2° vs. 36.4° ± 8.4°, p < 0.001), a higher apical vertebral rotation correction (10.6° ± 3.9° vs. 4.8° ± 2.6°, p < 0.001), and reduced the progression of major curve angle after the 2-year follow-up (5.1° ± 2.9° vs. 8.7° ± 4.8°, p < 0.001). A moderate correlation was observed between the magnitude of correction of apical vertebral rotation angle and major curve (r = 0.528, p = 0.002).ConclusionThis study demonstrated that hybrid instrumentation can provide a greater magnitude of correction in major curve and apical rotation, as well as less major curve progression in comparison with sublaminar wire in patients with SMA scoliosis.Level of evidence III


Author(s):  
X Wang ◽  
CE Aubin ◽  
RM Schwend

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.


2019 ◽  
Vol 8 (3) ◽  
pp. 377 ◽  
Author(s):  
Minerva Granado-Casas ◽  
Esmeralda Castelblanco ◽  
Anna Ramírez-Morros ◽  
Mariona Martín ◽  
Nuria Alcubierre ◽  
...  

Diabetic retinopathy (DR) may potentially cause vision loss and affect the patient’s quality of life (QoL) and treatment satisfaction (TS). Using specific tools, we aimed to assess the impact of DR and clinical factors on the QoL and TS in patients with type 1 diabetes. This was a cross-sectional, two-centre study. A sample of 102 patients with DR and 140 non-DR patients were compared. The Audit of Diabetes-Dependent Quality of Life (ADDQoL-19) and Diabetes Treatment Satisfaction Questionnaire (DTSQ-s) were administered. Data analysis included bivariate and multivariable analysis. Patients with DR showed a poorer perception of present QoL (p = 0.039), work life (p = 0.037), dependence (p = 0.010), and had a lower average weighted impact (AWI) score (p = 0.045). The multivariable analysis showed that DR was associated with a lower present QoL (p = 0.040), work life (p = 0.036) and dependence (p = 0.016). With regards to TS, DR was associated with a higher perceived frequency of hypoglycaemia (p = 0.019). In patients with type 1 diabetes, the presence of DR is associated with a poorer perception of their QoL. With regard to TS, these subjects also show a higher perceived frequency of hypoglycaemia.


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