Novel Method for Evaluation of Sagittal Spinal Alignment Using Cluster Analysis of Slope of Each Vertebra.

Abstract Background: The parameters of sagittal spinal alignment proposed to date measure only the specific sectional angle or the specific sectional distance of the entire spine. To evaluate the alignment of the entire spine without segmentation, we sought to measure and analyze the slope of each vertebral body from skull to pelvis. The purpose of this study was to confirm the effectiveness of this novel analytic method for the evaluation of spinal alignment that considers the slope of each spinal vertebra using graph and cluster analysis.Methods: Every spinal slope from McGregor’s slope to the sacral slope of 88 patients who underwent standing whole spine radiography was measured. Subsequently, we conducted cluster analysis of each spinal slope to understand the characteristics of sagittal alignment.Results: Cluster analysis of whole spinal slopes did not provide useful results in this study because the number of cases per cluster was small due to the large number of parameters. Therefore, we focused the cluster analysis on only the cervical spine slopes. Then, we categorized cervical alignment into four groups (named Normal, Mismatch, Straight, and Sigmoid) based on the results of the cluster analysis. Patients in the Normal and Mismatch groups were older and had lower lumbar apex (L4), apparent lordo-kyphosis around the thoracolumbar junction, and high thoracic kyphosis (TK). Patients in the straight and sigmoid groups were younger, had a higher lumbar apex (L3), flat thoracolumbar junction, and low TK. There was no significant difference between the four groups with respect to pelvic incidence (PI) or pelvic tilt (PT).Conclusion: We proposed a novel method for visually understanding sagittal alignment. Using this analysis method, differences and similarities of sagittal alignment between each group can be easily identified. More detailed analysis of the whole spine may be possible by increasing the number of cases.

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Global sagittal spinal alignment in patients with degenerative low-grade lumbar spondylolisthesis

Journal of Orthopaedic Surgery ◽

10.1177/2309499019885190 ◽

2019 ◽

Vol 27 (3) ◽

pp. 230949901988519

Author(s):

Hiroto Kobayashi ◽

Kenji Endo ◽

Yasunobu Sawaji ◽

Yuji Matsuoka ◽

Hirosuke Nishimura ◽

...

Keyword(s):

Sacral Slope ◽

Low Grade ◽

Spinal Alignment ◽

Sagittal Spinal Alignment ◽

Significant Difference ◽

Degenerative Lumbar Spondylolisthesis ◽

Lumbar Spondylolisthesis ◽

Type 3

Purpose: Global sagittal spinal alignment undergoes changes on the basis of sagittal malalignment (trunk inclined forward) in natural degenerative progression. We hypothesized that this change would associate with the disease state of the degenerative lumbar spondylolisthesis (DS). This study aimed to evaluate the global sagittal spinal alignment of low-grade DS by classifying in accordance with sagittal vertical axis (SVA). Methods: The DS group was classified into three types according to the adult spinal deformity classification: type 1, SVA < 40 mm; type 2, 40 mm ≤ SVA < 95 mm; and type 3, 95 mm ≤ SVA. Age and sagittal spinal parameters (thoracic kyphosis, lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI)) were compared among three types. Results: There were statistically significant differences in age, LL, PI, and PT among the three types. In comparison between two types, there was a statistically significant difference between type 1 and type 2 and between type 1 and type 3, but not between type 2 and type 3 in these parameters. PI tended to increase as the type increases. Furthermore, there was significant difference between types 1 and 3. Conclusion: We evaluated the features of the DS types classified by sagittal alignment. Large PI is one of the risk factors for SVA deterioration of DS. PI may be involved in the onset and progression of DS.

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Global sagittal spinal alignment at cervical flexion in patients with dropped head syndrome

Journal of Orthopaedic Surgery ◽

10.1177/2309499020948266 ◽

2020 ◽

Vol 28 (3) ◽

pp. 230949902094826 ◽

Cited By ~ 1

Author(s):

Takamitsu Konishi ◽

Kenji Endo ◽

Takato Aihara ◽

Hidekazu Suzuki ◽

Yuji Matsuoka ◽

...

Keyword(s):

Thoracic Spine ◽

Vertical Axis ◽

Control Group ◽

Sacral Slope ◽

Neutral Position ◽

Spinal Alignment ◽

Sagittal Vertical Axis ◽

Dropped Head Syndrome ◽

Sagittal Spinal Alignment ◽

Significant Difference

Purpose: Dropped head syndrome (DHS) is characterized by the passively correctable chin-on-chest deformity. The characteristic feature is emphasized in the cervical flexion position. The purpose of this study was to analyze the influence of cervical flexion on sagittal spinal alignment in patients with DHS. Methods: The study included 15 DHS subjects and 55 cervical spondylosis (CS) subjects as the control group. The following parameters were analyzed: cervical sagittal vertical axis (C-SVA), occipitoaxial angle (O–C2A), C2 slope (C2S), C2–C7 angle (C2–C7A), T1 slope (T1S), sagittal vertical axis, T1–T4 angle (T1–T4A), T5–T8 angle (T5–T8A), T9–T12 angle, lumbar lordosis, sacral slope, and pelvic tilt, in cervical flexion and neutral positions. Results: The values of C-SVA, O–C2A, C2S, and T1S were significantly different between CS and DHS at cervical neutral and flexion positions. C2–C7A showed significant difference in cervical neutral position, but the difference disappeared in flexion position. T1–T4A did not present a significant difference, but T5–T8A showed a difference in neutral and flexion positions. Conclusions: Malalignment of DHS extended not only to cervical spine but also to cranio-cervical junction and thoracic spine, except T1–T4. It is known that global sagittal spinal alignment is correlated with adjacent parameters, although in DHS the reciprocal change was lost from cranio-cervical junction to the middle part of thoracic spine at cervical flexion.

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The different compensatory mechanism of sagittal spinopelvis in patients with LDH and patients with spondylolisthesis

10.21203/rs.2.13163/v1 ◽

2019 ◽

Author(s):

Weifei Wu ◽

Jie Liang ◽

Ying Chen ◽

Zong Yang ◽

Neng Ru ◽

...

Keyword(s):

Sagittal Alignment ◽

Normal Population ◽

Compensatory Mechanism ◽

Spinal Alignment ◽

X Ray ◽

Spinopelvic Alignment ◽

Whole Spine

Abstract Background: few studies focusing on the differences of spinopelvic alignment between patients with LDH and patients with SPL were reported. The aim of this study was to study differences of spinopelvic alignment and to analyze differences of correlation between sagittal alignment parameters among patients with LDH and SPL, and normal population. Methods: Standard up-standing antero-posterior and lateral X-ray of the whole spine were preformed in all subjects. Evidence of LDH was confirmed by CT or MRI. SPL was diagnosed by X-ray or MRI. The parameters were measured included TK, LL, PI, SS, PT and SVA in lateral radiography. Results: 60 patients with LDH, 62 patients with SPL and 57 normal were included. Significant differences as for the SS, TK, LL and SVA (P <0.05) was found among three groups. PI of SPL patients was the highest among the three groups (P <0.05). PT of both SPL patients and LDH patients were significant higher than controls’ (P <0.05). LL of LDH patients was the lowest among the three groups (P <0.05). PI was less correlated with LL (P <0.05) in patients with LDH and SPL. PT was more strongly negative correlated with SS, LL and TK in LDH group (P <0.05). SS was more strongly positive correlated with TK (P <0.05), and SS and LL were more strongly negative correlated with SVA (P <0.05) in LDH patients. Conclusion: Those results showed a disharmonious spinopelvic relationship and exhibited different compensatory models of spine to adapt changes in spinal alignment in LDH patients and SPL patients.

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Comparison of Sagittal Spinal Alignment on Standing Plain X-Rays and Supine MRI in Degenerative Lumbar Disease

10.21203/rs.3.rs-26627/v1 ◽

2020 ◽

Author(s):

Yulu Wang ◽

Jinwu Bai ◽

Zhijun Pan ◽

Deting Xue

Keyword(s):

Sagittal Alignment ◽

Correlation Coefficients ◽

Sacral Slope ◽

X Rays ◽

Degenerative Lumbar Diseases ◽

Angle Measurements ◽

Sagittal Spinal Alignment ◽

Spinal Sagittal Alignment ◽

Degenerative Lumbar Disease ◽

Magnetic Resonance Imaging Mri

Abstract Background:The purpose of present study is to examine the possible correlation between standing plain X-rays and supine MRI for evaluating spinal sagittal alignment in degenerative lumbar disease.Methods: The characteristics and images of 64 patients with degenerative lumbar diseases were reviewed retrospectively. The thoracolumbar junction kyphosis (TJK), lumbar lordosis (LL), and sacral slope (SS) were measured on lateral plain X-rays and by magnetic resonance imaging (MRI). Inter- and intra-observer reliability were tested using intra-class correlation coefficients. Results: The results suggested that TJK measurements obtained from MRI tended to underestimate the radiographic measures by 2°, whereas SS measurements obtained from MRI tended to overestimate the radiographic measures by 2°. The LL measurements obtained from MRI were approximately equal to the radiographic measures. The X-ray and MRI measurements were linearly related. Conclusions:In conclusion, supine MRI can be directly translated into sagittal alignment angle measurements obtained from standing X-rays with an acceptable degree of accuracy. This can avoid the impaired view caused by the overlapping ilium, while reducing the patient’s exposure to radiation.

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The Effects of Force That Pushes Forward Lumbar Region on Sagittal Spinal Alignment When Wearing Backpack

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph16193643 ◽

2019 ◽

Vol 16 (19) ◽

pp. 3643

Author(s):

Tae-sung In ◽

Seung-man Yu ◽

Sang-hun Jang

Keyword(s):

Lumbar Lordosis ◽

Sagittal Plane ◽

The State ◽

Sacral Slope ◽

Lumbar Region ◽

Spinal Alignment ◽

Inferior Angle ◽

Sagittal Spinal Alignment ◽

Lumbar Alignment ◽

Adult Volunteers

The purpose of this study is to design a backpack to push the lumbar region forward and confirm the change in the sagittal plane of the spine using radiography when wearing the backpack to present an effective backpack wearing method that can help spinal alignment. Place the question addressed in a broad context and highlight the purpose of the study. A total of 14 adult volunteers participated in the study. The study was carried out on the subjects without carrying a backpack, with a general backpack, and with a backpack designed to push the lumbar region forward. We investigated cervical, thoracic, lumbar, and sacral alignment under these three conditions. Lumbar lordosis showed a significant decrease in the state of wearing a general backpack compared to the case without a backpack, and a significant increase in the state of wearing a backpack designed to push the lumbar region forward rather than a general backpack. In addition, the sacral slope was significantly increased when carrying the backpack designed to push the lumbar region forward, compared to carrying the general backpack. There was a significant correlation between the sacral and lumbar alignment change when wearing the backpack compared to the state without a backpack. The results of this study indicate that wearing a backpack designed to push the lumbar region forward may contribute to the recovery of lumbar lordosis that is reduced when wearing a general backpack. This may be due to an increase in the sacral slope corresponding to the inferior angle of lumbar spine.

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Spinal alignment shift between supine and prone CT imaging occurs frequently and regardless of the anatomic region, risk factors, or pathology

Neurosurgical Review ◽

10.1007/s10143-021-01618-x ◽

2021 ◽

Author(s):

Lars Wessels ◽

Bettina Komm ◽

Georg Bohner ◽

Peter Vajkoczy ◽

Nils Hecht

Keyword(s):

Risk Factors ◽

Spine Surgery ◽

Sagittal Alignment ◽

Posterior Instrumentation ◽

Ct Imaging ◽

Computer Assisted ◽

Significant Shift ◽

Spinal Alignment ◽

Sagittal Spinal Alignment ◽

Anatomic Region

AbstractComputer-assisted spine surgery based on preoperative CT imaging may be hampered by sagittal alignment shifts due to an intraoperative switch from supine to prone. In the present study, we systematically analyzed the occurrence and pattern of sagittal spinal alignment shift between corresponding preoperative (supine) and intraoperative (prone) CT imaging in patients that underwent navigated posterior instrumentation between 2014 and 2017. Sagittal alignment across the levels of instrumentation was determined according to the C2 fracture gap (C2-F) and C2 translation (C2-T) in odontoid type 2 fractures, next to the modified Cobb angle (CA), plumbline (PL), and translation (T) in subaxial pathologies. One-hundred and twenty-one patients (C1/C2: n = 17; C3-S1: n = 104) with degenerative (39/121; 32%), oncologic (35/121; 29%), traumatic (34/121; 28%), or infectious (13/121; 11%) pathologies were identified. In the subaxial spine, significant shift occurred in 104/104 (100%) cases (CA: *p = .044; T: *p = .021) compared to only 10/17 (59%) cases that exhibited shift at the C1/C2 level (C2-F: **p = .002; C2-T: *p < .016). The degree of shift was not affected by the anatomic region or pathology but significantly greater in cases with an instrumentation length > 5 segments (“∆PL > 5 segments”: 4.5 ± 1.8 mm; “∆PL ≤ 5 segments”: 2 ± 0.6 mm; *p = .013) or in revision surgery with pre-existing instrumentation (“∆PL presence”: 5 ± 2.6 mm; “∆PL absence”: 2.4 ± 0.7 mm; **p = .007). Interestingly, typical morphological instability risk factors did not influence the degree of shift. In conclusion, intraoperative spinal alignment shift due to a change in patient position should be considered as a cause for inaccuracy during computer-assisted spine surgery and when correcting spinal alignment according to parameters that were planned in other patient positions.

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Cervical sagittal alignment in patients with dropped head syndrome

Journal of Orthopaedic Surgery ◽

10.1177/2309499021990112 ◽

2021 ◽

Vol 29 (1) ◽

pp. 230949902199011

Author(s):

Weiqing Qian ◽

Kenji Endo ◽

Takato Aihara ◽

Yasunobu Sawaji ◽

Hidekazu Suzuki ◽

...

Keyword(s):

Cervical Spondylosis ◽

Sagittal Alignment ◽

Vertical Axis ◽

Spinal Alignment ◽

Sagittal Vertical Axis ◽

Dropped Head Syndrome ◽

Sagittal Spinal Alignment ◽

Cervical Sagittal Alignment ◽

Lumbar Alignment ◽

The Relationship

Background: Dropped head syndrome (DHS) can be divided into two types, the positive sagittal vertical axis (SVA) type and the negative SVA type. However, the cervical sagittal alignment of DHS including global sagittal spinal alignment and the typical cervical alignment of the types of DHS is still unclear. The purpose of this study was to clarify the character of cervical sagittal alignment of DHS and analyze the relationship between cervical sagittal alignment and global sagittal spinal alignment. Methods: The subjects were 35 DHS patients (10 men, 25 women, mean 71.1 years old). They were divided into two groups: negative DHS (N-DHS group, SVA < 0 mm) and positive DHS group (P-DHS group, SVA ≥ 0 mm). As control, 28 age-matched cervical spondylosis patients (CS, 21 men, 7 women, mean 67.4 years old) were analyzed. The following parameters were measured on lateral global-spine standing radiographs: cervical SVA (C2-C7SVA), O-C2A (O-C2 angle), C2 slope (C2S), C2-7A (C2-7 angle), T1 slope (T1S) and C7SVA. Results: The results of measurements of each of the averaged sagittal alignment parameters were (CS, P-DHS, N-DHS): C2-7SVA(26.2 mm, 47.3 mm, 44.5 mm), O-C2 angle (35.0°, 37.1°, 39.3°), C2S (16.5°, 31.4°, 33.8°), C2-7A (9.3°, 9.9°, −16.6°), T1S (22.9°, 39.7°, 25.7°), C7SVA (35.3 mm, 51.0 mm, −43.1 mm). C2-C7SVA and C2S were significantly larger in both types of DHS compared to CS. Comparing P-DHS with N-DHS, C2-C7A and T1S were significantly smaller in N-DHS. Conclusions: O-C2A did not differ significantly among CS, P-DHS and N-DHS. In DHS patients, C2-7SVA and C2S were significantly larger than those of CS regardless of the type of DHS. The typical cervical sagittal alignment of DHS was different between P-DHS and N-DHS. In P-DHS, C2-7A and T1S were larger than those in N-DHS and the imbalance of thoraco-lumbar alignment should be noted.

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Correlation between lumbar sagittal alignment, Modic changes, and endplate erosion in patients with degenerative disease

10.21203/rs.3.rs-18890/v1 ◽

2020 ◽

Author(s):

Bin Lv ◽

Haosheng Wang

Keyword(s):

Lumbar Lordosis ◽

Sagittal Alignment ◽

Modic Changes ◽

Degenerative Disease ◽

Defect Group ◽

Sacral Slope ◽

Precise Understanding ◽

Significant Difference ◽

Before And After ◽

Operation Results

Abstract Purpose To explore the role of lumbar sagittal alignment in the occurrence of Modicchanges and endplate defects (MC&ED) development in patients with a spinal degenerative disease, and the relationship between lumbar sagittal alignment and patient-report outcomes. Background Increasing attention has been focused on MC&ED as playing a potential role in the etiopathogenesis of lumbar degeneration. The precise understanding of the mechanisms leading to progression of MC&ED is lacking. Hence, we investigated how lumbar sagittal alignment influences the MC&ED. Patients and methods Ninety-six consecutive asymptomatic or symptomatic patients with Modic changes or endplate defect were retrospectively recruited in this study from August 2016 to December 2018. MC&ED were observed in 76 patients and not observed in 20 patients, representing two groups for comparison. The lumbar sagittal parameters were measured, including lumbar lordosis (LL),pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT). The lumbar lordosis index (LLI) and idea LL were then calculated. Clinical outcomes were assessed using a visual analog scale(VAS) and a Oswestry Disability Index (ODI) before and after operation. Results There were no significant differences in the distribution of demographics and baseline clinical variables between both groups. Mean age and BMI showed a significant difference between both groups (P<0.05). There were significant correlations between LL, LLI, Lossof LL, and Level 1 (r=0.281, 0.230, and 0.284, P<0.05) Also, PI, PT were significantly correlated with Level 4 (r=0.249, 0.202, P<0.05).Compared with presurgery scores, an improvement was seen in postoperative VAS and ODI scores (P<0.05). Further, the postoperative scores at 24 months in the without Modicor end plate defect group showed greater improvements compared with the with Modic or endplate defect group (P<0.05). Conclusion This analysis indicated that maintaining lumbar sagittal alignment was related to a lower risk of Modic changes in patients with the spinal degenerative disease. The lumbar sagittal alignment might be a factor that influenced the posterior inclination of the pelvis in symptomatic lumbar disease.

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Small sagittal vertical axis accompanied with lumbar hyperlordosis as a risk factor for developing postoperative cervical kyphosis after expansive open-door laminoplasty

Journal of Neurosurgery Spine ◽

10.3171/2017.12.spine17557 ◽

2018 ◽

Vol 29 (2) ◽

pp. 176-181 ◽

Cited By ~ 3

Author(s):

Yuji Matsuoka ◽

Hidekazu Suzuki ◽

Kenji Endo ◽

Yasunobu Sawaji ◽

Kazuma Murata ◽

...

Keyword(s):

Vertical Axis ◽

Sagittal Imbalance ◽

Open Door ◽

Spinal Alignment ◽

Cervical Kyphosis ◽

Sagittal Vertical Axis ◽

Sagittal Spinal Alignment ◽

Lumbar Hyperlordosis ◽

The Difference ◽

Whole Spine

OBJECTIVEPreoperative positive cervical sagittal imbalance and global sagittal imbalance are risk factors for postoperative cervical kyphosis after expansive open-door cervical laminoplasty (ELAP). The purpose of this study was to investigate the relationship between the incidence of postoperative cervical kyphosis after ELAP and the preoperative global sagittal spinal alignment in patients with cervical spondylotic myelopathy (CSM) without spinal sagittal imbalance.METHODSAmong 84 consecutive patients who underwent ELAP for CSM at the authors’ hospital, 43 patients without preoperative cervical kyphosis (C2–7 angle ≥ 0°) and spinal sagittal imbalance (C2–7 sagittal vertical axis [SVA] ≤ 80 mm and C-7 SVA ≤ 95 mm) were included in the study. The global spinal sagittal parameters were measured on lateral whole-spine standing radiographs preoperatively and at 1 year postoperatively. The difference in preoperative global sagittal spinal alignment between the postoperative cervical lordosis group and the cervical kyphosis group was analyzed.RESULTSThe incidence of postoperative cervical kyphosis after ELAP was 25.6% (11 of 43 cases). Thirty-two patients (16 men and 16 women; mean age 67.7 ± 12.0 years) had lordosis, and 11 (7 men and 4 women; mean age 67.2 ± 9.6 years) had kyphosis. The preoperative C-7 SVA and pelvic incidence minus lumbar lordosis (PI−LL) in the kyphosis group were significantly smaller than those in the lordosis group (p < 0.05). The smaller C-7 SVA accompanied by a small PI−LL, the “truncal negative offset,” led to postoperative cervical kyphosis due to posterior structural weakening by ELAP.CONCLUSIONSIn patients with CSM without preoperative cervical and global spinal sagittal imbalance, a small SVA accompanied by lumbar hyperlordosis is the characteristic alignment leading to postoperative cervical kyphosis after ELAP.

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Differences and similarities in the milk production chain: a comparative analysis with the states of Minas Gerais and Paraná

Independent Journal of Management & Production ◽

10.14807/ijmp.v12i4.1309 ◽

2021 ◽

Vol 12 (4) ◽

pp. 1034-1051

Author(s):

Adriano Oliveira Cruz ◽

José Kennedy Lopes Silva ◽

Elvis Magno da Silva ◽

Antônio Carlos dos Santos ◽

Luiz Marcelo Antonialli

Keyword(s):

Cluster Analysis ◽

Milk Production ◽

Technical Assistance ◽

Methodological Approach ◽

Minas Gerais ◽

Production Chain ◽

High Productivity ◽

Time Period ◽

Significant Difference ◽

And Cluster Analysis

Brazilian agriculture has played a prominent role all over the world, being milk production one of the exponents of the national agribusiness. The states of Minas Gerais and Paraná are protagonists in the milk production business in the country. The objective of this study was to evaluate the differences and similarities of the milk production chain in these two states, considering the period from 2008 to 2017, in order to investigate their dynamics and their competitiveness. The methodological approach adopted in the research was of a quantitative nature, with the use of the software “Statistical Package for the Social Sciences” (SPSS), which allowed the analysis to be carried out with the statistical techniques of analysis of variance (Anova) and cluster analysis. Ward’s agglomerative method and discriminant analysis were also adopted. The state of Minas Gerais presented a superior milk production chain in comparison with Paraná in every year analyzed; however, statistically there was no significant difference in the milk production from 2009 to 2017. Paraná presented better milk productivity averages as compared to Minas Gerais; it was highly significant (1%) from 2008 to 2016 and significant (5%) in 2017. The results of the cluster analysis indicated that, due to the fact that Paraná has higher productivity indexes in relation to Minas Gerais, its limits are better in relation to Minas Gerais in the analyzed aspects. It was found that some municipalities that are considered to have high productivity in Minas Gerais do not enter this same group in Paraná. It can be said that Paraná was shown to be more efficient in the milk production chain as compared to Minas Gerais in the analyzed time period. The article indicates the need to improve the technology used in the milk production chain, so that the numbers related to productivity can be improved. In addition, it was found that it is necessary to invest in genetics and technical assistance so that milk producers in the states surveyed can become more competitive.

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