Association between diffuse idiopathic skeletal hyperostosis and thoracic kyphosis in patients with cervical myelopathy: a retrospective observational study

Abstract Background Diffuse idiopathic skeletal hyperostosis (DISH) is a structural abnormality of the thoracic spine that is known to impair posture. However, the relationship between DISH and sagittal balance in the whole spine is unclear. The aims of this study were to investigate the prevalence of DISH in patients with cervical myelopathy caused by cervical ossification of the posterior longitudinal ligament (OPLL) or cervical spondylosis and to compare sagittal alignment of the spine between patients with and without DISH. Methods A total of 103 consecutive patients with a diagnosis of cervical myelopathy due to cervical OPLL or spondylosis were retrospectively enrolled in this single-center study. DISH was defined as an ossified lesion that was seen to be completely bridging at least four contiguous adjacent vertebral bodies in the thoracic spine on computed tomography scans. Cervical and spinopelvic sagittal parameters were measured in whole spine radiographs. Results The study population included 28 cases with DISH [DISH (+) group] and 75 without DISH [DISH (−) group]. OPLL was more prevalent in the DISH (+) group than in the DISH (−) group; however, there were no significant differences in other clinical findings. Propensity score matching produced 26 pairs. C7 slope, C2-7 sagittal vertical axis (C-SVA), whole thoracic kyphotic angles, upper thoracic kyphosis, and T5-T12 thoracic kyphosis values were significant higher in the DISH (+) group than in the DISH (−) group. There was no significant between-group difference in the other sagittal spinopelvic parameters. Conclusions This study is the first to compare sagittal alignment in patients with cervical myelopathy according to whether or not they have DISH. Patients with DISH are more likely to have excessive kyphosis in the thoracic spine, a high C7 slope, and a high C2-7 SVA.

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

Scientific Reports ◽

10.1038/s41598-020-79523-4 ◽

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.

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Normal Age-Adjusted Sagittal Spinal Alignment Is Achieved with Surgical Correction in Adolescent Idiopathic Scoliosis

Asian Spine Journal ◽

10.4184/asj.2017.11.5.770 ◽

2017 ◽

Vol 11 (5) ◽

pp. 770-779 ◽

Cited By ~ 1

Author(s):

Subaraman Ramchandran ◽

Norah Foster ◽

Akhila Sure ◽

Thomas J. Errico ◽

Aaron J. Buckland

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Lumbar Lordosis ◽

Thoracic Kyphosis ◽

Pelvic Incidence ◽

Sagittal Alignment ◽

Vertical Axis ◽

Surgical Correction ◽

Sagittal Vertical Axis

<sec><title>Study Design</title>Retrospective analysis.</sec><sec><title>Purpose</title>Our hypothesis is that the surgical correction of adolescent idiopathic scoliosis (AIS) maintains normal sagittal alignment as compared to age-matched normative adolescent population.</sec><sec><title>Overview of Literature</title>Sagittal spino-pelvic alignment in AIS has been reported, however, whether corrective spinal fusion surgery re-establishes normal alignment remains unverified.</sec><sec><title>Methods</title>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.</sec><sec><title>Results</title>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><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.</sec><sec><title>Conclusions</title>Surgical correction of the coronal plane in AIS patients preserves sagittal and spino-pelvic alignment as compared to age-matched asymptomatic adolescents.</sec>

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The Effect of Lumbar Spinal Muscle on Spinal Sagittal Alignment

Neurosurgery ◽

10.1227/neu.0000000000001269 ◽

2016 ◽

Vol 79 (6) ◽

pp. 847-855 ◽

Cited By ~ 27

Author(s):

Hyo Sub Jun ◽

Ji Hee Kim ◽

Jun Hyong Ahn ◽

In Bok Chang ◽

Joon Ho Song ◽

...

Keyword(s):

Magnetic Resonance ◽

Elderly Patients ◽

Thoracic Kyphosis ◽

Pelvic Tilt ◽

Sagittal Alignment ◽

Vertical Axis ◽

Magnetic Resonance Images ◽

Paraspinal Muscle ◽

Sagittal Vertical Axis ◽

Spinal Sagittal Alignment

Abstract BACKGROUND: The majority of earlier studies of the parameters of sagittal balance did not consider the influence of spinal muscles on spinal sagittal alignment. OBJECTIVE: To analyze the relationship between the paraspinal muscle (quantity and quality) and sagittal alignment in elderly patients. METHODS: We reviewed 50 full-spine lateral standing radiographs and lumbar magnetic resonance images of elderly patients at a single center. The radiographic parameters examined were thoracic kyphosis, lumbar lordosis (LL), sagittal vertical axis, pelvic tilt, sacral slope, and pelvic incidence (PI). The lumbar muscularity (LM; quantity) and fatty degeneration ratio (FD; quality) in the paraspinal muscle were measured at the L3 level on magnetic resonance images. The relationships between the parameters, LM, and FD were analyzed with the Pearson correlation coefficient and multiple linear regression. RESULTS: Pearson analysis demonstrated that the FD had significant correlations with age (r = 0.393), thoracic kyphosis (r = −0.559), pelvic tilt (r = 0.430), sagittal vertical axis (r = 0.488), and PI − LL (r = 0.479, P < .05), and a close negative correlation was found between the FD and LL (r = −0.505, P < .01). The LM had significant correlations with the LL (r = 0.342) and PI − LL (r = −0.283, P < .05). Regression models that controlled for confounding factors such as body mass index confirmed the correlations between the above parameters and FD (P < .05). CONCLUSION: The quality of the paraspinal muscle could be one of the various factors that influence sagittal balance.

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Comparison study of clinical outcomes and sagittal alignment improvement between anterior and posterior fusion techniques for multilevel cervical spondylotic myelopathy

Journal of Orthopaedic Surgery ◽

10.1177/2309499020988177 ◽

2021 ◽

Vol 29 (1) ◽

pp. 230949902098817

Author(s):

Hui Liu ◽

Xiang Li ◽

Jianru Wang ◽

Zemin Li ◽

Zihao Li ◽

...

Keyword(s):

Clinical Outcomes ◽

Cervical Spondylotic Myelopathy ◽

Sagittal Alignment ◽

Vertical Axis ◽

Anterior Cervical Discectomy ◽

Sagittal Vertical Axis ◽

Cervical Discectomy ◽

Cervical Corpectomy ◽

C7 Slope ◽

Anterior Cervical Corpectomy

Purpose: To compare the sagittal alignment of different surgical approaches in patients with multiple levels cervical spondylotic myelopathy and explore the relationship between the cervical sagittal alignment and patient’s health relative quality of life. Method: A total of 97 multiple levels cervical spondylotic myelopathy patients who underwent surgery from January 2013 to January 2019 were collected in this study. Patients were divided into three groups: anterior cervical discectomy with fusion, anterior cervical corpectomy with fusion and laminectomy with fusion groups. Clinical outcomes and sagittal alignment parameters were compared preoperative and postoperative. Results: There were no significant differences in the average age and sex ratio among the groups. Sagittal parameters correlated to health relative quality of life were C7 slope, occipito-C2 angle, external auditory meatus tilt and cervical sagittal vertical axis. Both anterior cervical discectomy with fusion and anterior cervical corpectomy with fusion groups exhibited better sagittal alignment and clinical outcomes improvement postoperatively. Anterior cervical discectomy with fusion provided better clinical outcomes and the better improvement of cervical lordosis, C7 slope, occipito-C2 angle and cervical sagittal vertical axis compared with patients with Laminectomy with fusion. Conclusion: C7 slope, occipito-C2 angle, external auditory meatus tilt and cervical sagittal vertical axis are the most important cervical sagittal parameters correlated to clinical outcomes in patients with multilevels cervical spondylotic myelopathy; anterior cervical discectomy with fusion and anterior cervical corpectomy with fusion provides more efficient to restoration of cervical sagittal alignment.

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The Pelvic Incidence Stratified Sagittal Spinopelvic Alignment in Asymptomatic Chinese Population With Different Age Groups

Global Spine Journal ◽

10.1177/2192568221989647 ◽

2021 ◽

pp. 219256822198964

Author(s):

Siyu Zhou ◽

Zhuoran Sun ◽

Wei Li ◽

Da Zou ◽

Weishi Li

Keyword(s):

Chinese Population ◽

Pelvic Incidence ◽

Sagittal Alignment ◽

Age Groups ◽

Vertical Axis ◽

Elderly Subjects ◽

Sagittal Vertical Axis ◽

Cross Sectional ◽

Sagittal Parameters ◽

Very High

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.

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Lumbar Level Significantly Influences Postoperative Global Sagittal Balance Following Pedicle Subtraction Osteotomy

Global Spine Journal ◽

10.1177/21925682211032563 ◽

2021 ◽

pp. 219256822110325

Author(s):

Athan G. Zavras ◽

T. Barrett Sullivan ◽

Navya Dandu ◽

Howard S. An ◽

Christopher J. DeWald ◽

...

Keyword(s):

Sagittal Balance ◽

Sagittal Alignment ◽

Adult Spinal Deformity ◽

Vertical Axis ◽

Pedicle Subtraction Osteotomy ◽

Current Evidence ◽

Sacral Slope ◽

Sagittal Vertical Axis ◽

Lumbar Level ◽

Global Sagittal Alignment

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.

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Specific sagittal alignment patterns are already present in mild adolescent idiopathic scoliosis

European Spine Journal ◽

10.1007/s00586-021-06772-w ◽

2021 ◽

Author(s):

Tom P. C. Schlösser ◽

René M. Castelein ◽

Pierre Grobost ◽

Suken A. Shah ◽

Kariman Abelin-Genevois

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Inflection Point ◽

Thoracic Kyphosis ◽

Sagittal Alignment ◽

Three Dimensional ◽

Sagittal Profile ◽

Thoracolumbar Kyphosis ◽

C7 Slope ◽

Sagittal Malalignment

Abstract Purpose The complex three-dimensional spinal deformity in AIS consists of rotated, lordotic apical areas and neutral junctional zones that modify the spine’s sagittal profile. Recently, three specific patterns of thoracic sagittal ‘malalignment’ were described for severe AIS. The aim of this study is to define whether specific patterns of pathological sagittal alignment are already present in mild AIS. Methods Lateral spinal radiographs of 192 mild (10°–20°) and 253 severe (> 45°) AIS patients and 156 controls were derived from an international consortium. Kyphosis characteristics (T4–T12 thoracic kyphosis, T10–L2 angle, C7 slope, location of the apex of kyphosis and of the inflection point) and sagittal curve types according to Abelin-Genevois were systematically compared between the three cohorts. Results Even in mild thoracic AIS, already 49% of the curves presented sagittal malalignment, mostly thoracic hypokyphosis, whereas only 13% of the (thoraco) lumbar curves and 6% of the nonscoliosis adolescents were hypokyphotic. In severe AIS, 63% had a sagittal malalignment. Hypokyphosis + thoracolumbar kyphosis occurred more frequently in high-PI and primary lumbar curves, whereas cervicothoracic kyphosis occurred more in double thoracic curves. Conclusions Pathological sagittal patterns are often already present in curves 10°–20°, whereas those are rare in non-scoliotic adolescents. This suggests that sagittal ‘malalignment’ patterns are an integral part of the early pathogenesis of AIS.

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The utility of supine radiographs in the assessment of thoracic flexibility and risk of proximal junctional kyphosis

Journal of Neurosurgery Spine ◽

10.3171/2020.11.spine201565 ◽

2021 ◽

pp. 1-7

Author(s):

Francis Lovecchio ◽

Renaud Lafage ◽

Jonathan Charles Elysee ◽

Alex Huang ◽

Bryan Ang ◽

...

Keyword(s):

Thoracic Spine ◽

Lumbar Lordosis ◽

Pelvic Tilt ◽

Pelvic Incidence ◽

Vertical Axis ◽

Control Analysis ◽

Proximal Junctional Kyphosis ◽

Sagittal Vertical Axis ◽

Significant Difference ◽

Junctional Kyphosis

OBJECTIVE Supine radiographs have successfully been used for preoperative planning of lumbar deformity corrections. However, they have not been used to assess thoracic flexibility, which has recently garnered attention as a potential contributor to proximal junctional kyphosis (PJK). The purpose of this study was to compare supine to standing radiographs to assess thoracic flexibility and to determine whether thoracic flexibility is associated with PJK. METHODS A retrospective study was conducted of a single-institution database of patients with adult spinal deformity (ASD). Sagittal alignment parameters were compared between standing and supine and between pre- and postoperative radiographs. Thoracic flexibility was determined as the change between preoperative standing thoracic kyphosis (TK) and preoperative supine TK, and these changes were measured over the overall thoracic spine and the fused portion of the thoracic spine (i.e., TK fused). A case-control analysis was performed to compare thoracic flexibility between patients with PJK and those without (no PJK). The cohort was also stratified into three groups based on thoracic flexibility: kyphotic change (increased TK), lordotic change (decreased TK), and no change. The PJK rate was compared between the cohorts. RESULTS A total of 101 patients (mean 63 years old, 82.2% female, mean BMI 27.4 kg/m2) were included. Preoperative Scoliosis Research Society–Schwab ASD classification showed moderate preoperative deformity (pelvic tilt 27.7% [score ++]; pelvic incidence–lumbar lordosis mismatch 44.6% [score ++]; sagittal vertical axis 42.6% [score ++]). Postoperatively, the average offset from age-adjusted alignment goals demonstrated slight overcorrection in the study sample (−8.5° ± 15.6° pelvic incidence–lumbar lordosis mismatch, −29.2 ± 53.1 mm sagittal vertical axis, −5.4 ± 10.8 pelvic tilt, and −7.6 ± 11.7 T1 pelvic angle). TK decreased between standing and supine radiographs and increased postoperatively (TK fused: −25.3° vs −19.6° vs −29.9°; all p < 0.001). The overall rate of radiographic PJK was 23.8%. Comparisons between PJK and no PJK demonstrated that offsets from age-adjusted alignment goals were similar (p > 0.05 for all). There was a significant difference in the PJK rate when stratified by thoracic flexibility cohorts (kyphotic: 0.0% vs no change: 18.4% vs lordotic: 35.0%; p = 0.049). Logistic regression revealed thoracic flexibility (p = 0.045) as the only independent correlate of PJK. CONCLUSIONS Half of patients with ASD experienced significant changes in TK during supine positioning, a quality that may influence surgical strategy. Increased thoracic flexibility is associated with PJK, possibly secondary to fusing the patient’s spine in a flattened position intraoperatively.

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Sagittal alignment in Japanese elderly people - how much can we tolerate as normal sagittal vertical axis?

Scoliosis ◽

10.1186/1748-7161-10-s1-o34 ◽

2015 ◽

Vol 10 (S1) ◽

Author(s):

Tatsuya Yasuda ◽

Tomohiko Hasegawa ◽

Yu Yamato ◽

Sho Kobayashi ◽

Daisuke Togawa ◽

...

Keyword(s):

Elderly People ◽

Sagittal Alignment ◽

Vertical Axis ◽

Sagittal Vertical Axis ◽

Japanese Elderly

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Spinal sagittal alignment and head control in patients with cerebral palsy

Journal of Children s Orthopaedics ◽

10.1302/1863-2548.14.190160 ◽

2020 ◽

Vol 14 (1) ◽

pp. 17-23 ◽

Cited By ~ 1

Author(s):

Brice Ilharreborde ◽

Adrien de Saint Etienne ◽

Ana Presedo ◽

Anne-Laure Simon

Keyword(s):

Cerebral Palsy ◽

Sagittal Alignment ◽

Vertical Axis ◽

Sacral Slope ◽

Trunk Control ◽

Level Of Evidence ◽

Sagittal Vertical Axis ◽

Spinal Sagittal Alignment ◽

Trunk Posture ◽

Radiological Analysis

Purpose Spinal sagittal alignment restoration has been associated with improved functional outcomes and with reduced complications rates. Several limitations exist for radiological analysis in cerebral palsy (CP) patients. The goal of this study was to summarize the existing literature and report the important considerations to evaluate in a CP patient undergoing spinal surgery. Methods A retrospective radiological analysis was performed, including non-ambulant CP children with progressive scoliosis. Full-spine sitting radiographs performed pre-and postoperatively were required to measure spino-pelvic sagittal parameters. Result A total of 23 non-ambulating CP patients were included, mean age 16.0 years (standard error of the mean 0.5). Two distinct groups of patients were identified. Group 1 (61%) were patients with less trunk control (lumbar lordosis (LL) < 50°), retroverted and vertical pelvis (mean sacral slope (SS) 11.4° and pelvic tilt (PT) 38.1°) and anterior imbalance (mean sagittal vertical axis (SVA) 5.9 cm) and Group 2 (39%) were patients with better trunk control (LL > 60°, anteverted and horizontal pelvis (mean SS 49.3°, PT 9.7°) and posterior imbalance (mean SVA 5.8 cm). Postoperative measures showed significant impact of surgery with a PT reduction of 19° (p = 0.007), a mean SS increase of 15° (p = 0.04) and a LL gained of 10° (p = 0.2). Conclusion Sagittal spino-pelvic alignment in non-ambulating CP patients remains difficult to assess. The current literature is poor but our radiological study was able to define two distinct groups among Gross Motor Function Classification System (GMFCS) level V patients, based on the quality of their trunk control. All possible factors that may influence head and trunk posture should be systematically considered and optimized. Level of evidence Level IV

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