scholarly journals An assessment of the most reliable method to estimate the sagittal alignment of the cervical spine: analysis of a prospective cohort of 138 cases

2017 ◽  
Vol 26 (5) ◽  
pp. 572-576 ◽  
Author(s):  
Roland D. Donk ◽  
Michael G. Fehlings ◽  
Wim I. M. Verhagen ◽  
Hisse Arnts ◽  
Hans Groenewoud ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Vertebral Body ◽  
Sagittal Balance ◽  
Interrater Reliability ◽  
Sagittal Alignment ◽  
Controlled Trial ◽  
Cervical Alignment ◽  
Cervical Sagittal Alignment ◽  
Tangent Method ◽  
The Mean

OBJECTIVEAlthough there is increasing recognition of the importance of cervical spinal sagittal balance, there is a lack of consensus as to the optimal method to accurately assess the cervical sagittal alignment. Cervical alignment is important for surgical decision making. Sagittal balance of the cervical spine is generally assessed using one of two methods; namely, measuring the angle between C-2 and C-7, and drawing a line between C-2 and C-7. Here, the best method to assess sagittal alignment of the cervical spine is investigated.METHODSData from 138 patients enrolled in a randomized controlled trial (Procon) were analyzed. Two investigators independently measured the angle between C-2 and C-7 by using Harrison's posterior tangent method, and also estimated the shape of the sagittal curve by using a modified Toyama method. The mean angles of each quantitative assessment of the sagittal alignment were calculated and the results were compared. The interrater reliability for both methods was estimated using Cronbach's alpha.RESULTSFor both methods the interrater reliability was high: for the posterior tangent method it was 0.907 and for the modified Toyama technique it was 0.984. For a lordotic cervical spine, defined by the modified Toyama method, the mean angle (defined by Harrison's posterior tangent method) was 23.4° ± 9.9° (range 0.4°–52.4°), for a kyphotic cervical spine it was −2.2° ± 9.2° (range −16.1° to 16.9°), and for a straight cervical spine it was 10.5° ± 8.2° (range −11° to 36°).CONCLUSIONSAn absolute measurement of the angle between C-2 and C-7 does not unequivocally define the sagittal cervical alignment. As can be seen from the minimum and maximum values, even a positive angle between C-2 and C-7 could be present in a kyphotic spine. For this purpose, the modified Toyama method (drawing a line from the posterior inferior part of the vertebral body of C-2 to the posterior upper part of the vertebral body of C-7 without any measurements) is a better tool for a global assessment of cervical sagittal alignment.Clinical trial registration no.: ISRCTN41681847 (https://www.isrctn.com)

scholarly journals Evaluating Cervical Sagittal Alignment in Cervical Myelopathy: Are Sitting Cervical Radiographs and Standing Whole-Spine Radiographs Equally Useful?

2018 ◽  
Vol 9 (6) ◽  
pp. 591-597
Author(s):  
Yasuhiko Morimoto ◽  
Hideki Shigematsu ◽  
Eiichiro Iwata ◽  
Masato Tanaka ◽  
Akinori Okuda ◽  
...  
Keyword(s):  
Sagittal Alignment ◽  
Horizontal Line ◽  
Radiographic Appearance ◽  
Mean Values ◽  
Cervical Alignment ◽  
T1 Slope ◽  
Cervical Surgery ◽  
Cervical Sagittal Alignment ◽  
The Mean ◽  
Whole Spine

Study Design:Retrospective review of medical charts and radiographic data.Objectives:We aimed to clarify the differences in cervical alignment findings between sitting cervical lateral radiographs and standing whole-spine lateral radiographs with clavicle positioning in cervical spondylotic myelopathy (CSM) patients.Methods:We retrospectively evaluated the radiographs of 50 consecutive patients who underwent cervical surgery for CSM in our hospital. Cervical sagittal alignment was evaluated based on the C0-2 angles and C2-7 Gore and Cobb angles. Head position was evaluated in terms of the center of gravity of the head to C7 (CGH-C7) angle and the McGregor angle (ie, the angle between the McGregor line and a horizontal line). The T1-slope was also evaluated.Results:The mean values of the CGH-C7 angle and T1-slope were significantly lower, while the mean value of the McGregor angle was significantly higher on whole-spine lateral radiographs with clavicle positioning than on sitting cervical lateral radiographs. The mean values of the C0-2 and C2-7 angles did not differ significantly between the 2 radiographic positioning approaches.Conclusions:Using whole-spine lateral radiographs with clavicle positioning may result in a significantly lower T1-slope and a posterior tilt of the head. In the absence of a compensatory change in cervical alignment, clavicle positioning may force patients to adopt an upward gazing position of the head. These compensatory mechanisms should be considered while evaluating cervical alignment on whole-spine lateral radiographs with clavicle positioning. Surgical planning should take into account the effect of posture on the radiographic appearance of cervical alignment.

scholarly journals Cervical spine alignment, sagittal deformity, and clinical implications

2013 ◽  
Vol 19 (2) ◽  
pp. 141-159 ◽  
Author(s):  
Justin K. Scheer ◽  
Jessica A. Tang ◽  
Justin S. Smith ◽  
Frank L. Acosta ◽  
Themistocles S. Protopsaltis ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Cervical Myelopathy ◽  
Sagittal Alignment ◽  
Deformity Correction ◽  
Adjacent Segment ◽  
Sagittal Vertical Axis ◽  
Cervical Alignment ◽  
Cervical Deformity ◽  
Cervical Sagittal Alignment ◽  
Global Sagittal Alignment

This paper is a narrative review of normal cervical alignment, methods for quantifying alignment, and how alignment is associated with cervical deformity, myelopathy, and adjacent-segment disease (ASD), with discussions of health-related quality of life (HRQOL). Popular methods currently used to quantify cervical alignment are discussed including cervical lordosis, sagittal vertical axis, and horizontal gaze with the chin-brow to vertical angle. Cervical deformity is examined in detail as deformities localized to the cervical spine affect, and are affected by, other parameters of the spine in preserving global sagittal alignment. An evolving trend is defining cervical sagittal alignment. Evidence from a few recent studies suggests correlations between radiographic parameters in the cervical spine and HRQOL. Analysis of the cervical regional alignment with respect to overall spinal pelvic alignment is critical. The article details mechanisms by which cervical kyphotic deformity potentially leads to ASD and discusses previous studies that suggest how postoperative sagittal malalignment may promote ASD. Further clinical studies are needed to explore the relationship of cervical malalignment and the development of ASD. Sagittal alignment of the cervical spine may play a substantial role in the development of cervical myelopathy as cervical deformity can lead to spinal cord compression and cord tension. Surgical correction of cervical myelopathy should always take into consideration cervical sagittal alignment, as decompression alone may not decrease cord tension induced by kyphosis. Awareness of the development of postlaminectomy kyphosis is critical as it relates to cervical myelopathy. The future direction of cervical deformity correction should include a comprehensive approach in assessing global cervicalpelvic relationships. Just as understanding pelvic incidence as it relates to lumbar lordosis was crucial in building our knowledge of thoracolumbar deformities, T-1 incidence and cervical sagittal balance can further our understanding of cervical deformities. Other important parameters that account for the cervical-pelvic relationship are surveyed in detail, and it is recognized that all such parameters need to be validated in studies that correlate HRQOL outcomes following cervical deformity correction.

Cervical malalignment after laminoplasty: relationship to deep extensor musculature of the cervical spine and neurological outcome

2007 ◽  
Vol 7 (6) ◽  
pp. 610-614 ◽  
Author(s):  
Haku Iizuka ◽  
Takashi Nakajima ◽  
Yoichi Iizuka ◽  
Yasunori Sorimachi ◽  
Tsuyoshi Ara ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Neurological Outcome ◽  
Neurological Recovery ◽  
Cervical Lordosis ◽  
Cervical Alignment ◽  
Female Patients ◽  
Group A ◽  
The Mean ◽  
Group B ◽  
The Relationship

Object The goal of this study was to investigate the relationship between preservation of the insertion of the deep extensor musculature of the cervical spine at C-2 and postoperative cervical alignment, especially differences between cases involving male and female patients, as well as the relationship between the loss of cervical lordosis and neurological outcome after laminoplasty. Methods The authors reviewed the records of 50 patients who underwent laminoplasty to elevate the C-3 lamina with repair of the deep extensor musculature (Group A) and 31 patients who underwent laminoplasty by C-3 dome laminotomy or laminectomy (Group B). They compared the degree of cervical lordosis after laminoplasty with preoperative measurements. Neurological function at last follow-up was also compared with preoperative assessments. Results In Group A, the mean values for pre- and postoperative cervical lordosis were 14.5 and 10.9°, respectively (p > 0.18). In female patients, however, the pre- and postoperative means were 14.4 and 3.7°, respectively (p < 0.004). In Group B, the overall means for pre- and postoperative cervical lordosis were 17.3 and 19.1°, respectively (p > 0.48); the corresponding means for female patients were 15.0 and 14.1° (p > 0.83). The mean percentages of neurological recovery were 54.1% in Group A and 54.8% in Group B. Conclusions Preservation of the insertion of the deep extensor musculature to the C-2 spinous process prevented significant changes in cervical alignment after laminoplasty, even among female patients. Neurological recovery was not affected by the loss of cervical lordosis.

scholarly journals Sagittal balance of the cervical spine: an analysis of occipitocervical and spinopelvic interdependence, with C-7 slope as a marker of cervical and spinopelvic alignment

2015 ◽  
Vol 23 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Susan Núñez-Pereira ◽  
Wolfgang Hitzl ◽  
Viola Bullmann ◽  
Oliver Meier ◽  
Heiko Koller
Keyword(s):  
Cervical Spine ◽  
Sagittal Alignment ◽  
Thoracolumbar Spine ◽  
Sacral Slope ◽  
Horizontal Line ◽  
Lower Cervical Spine ◽  
Compensatory Mechanisms ◽  
Spinopelvic Alignment ◽  
Asymptomatic Patients ◽  
Cervical Sagittal Alignment

OBJECT Sagittal malalignment of the cervical spine has been associated with worsened postsurgical outcomes. For better operative planning of fusion and alignment restoration, improved knowledge of ideal fusion angles and interdependences between upper and lower cervical spine alignment is needed. Because spinal and spinopelvic parameters might play a role in cervical sagittal alignment, their associations should be studied in depth. METHODS The authors retrospectively analyzed digital lateral standing cervical radiographs of 145 patients (34 asymptomatic, 74 symptomatic; 37 surgically treated), including full-standing radiographs obtained in 45 of these patients. Sagittal measurements were as follows: C2–7, occiput (Oc)–C2, C1–2 Cobb angles, and C-7 slope (the angle between the horizontal line and the superior endplate of C-7), as well as T4–12 and L1–S1 Cobb angles, sacral slope, pelvic incidence, and C-7 sagittal vertical axis (SVA). A correlation analysis was performed, and linear regression models were developed. RESULTS Statistical analyses revealed significant correlations between C2–7 and Oc–C2 (r = −0.4, p < 0.01), Oc–C2 (r = −0.3, p < 0.01), and C1–2 angle (r = −0.3, p < 0.01). C-7 slope was significantly correlated with C2–7 (r = −0.5, p < 0.01) and with Oc–C2 angle (r = 0.2, p = 0.02). Total cervical (Oc–C7) lordosis was 30.2° and did not differ significantly among asymptomatic, symptomatic, and surgically treated patients. Correlations between C2–7 and Oc–C2 alignment were stronger in asymptomatic patients (r = –0.5, p < 0.01) and surgically treated patients (r = –0.5, p < 0.01) than in symptomatic patients (r = –0.3, p = 0.01), but the between-group difference was not significant (p > 0.1). Comparing cervical and spinopelvic alignment revealed a significant correlation between sacral slope and C-7 slope (r = –0.3, p = 0.04) and C2–7 (r = 0.4, p < 0.01). The C-7 SVA correlated significantly with the C-7 slope (r = –0.4, p < 0.01). The interdependences were stronger within the occipitocervical parameters than between the cervical and remaining spinal parameters. CONCLUSIONS Significant correlations between the upper and lower cervical spine exist, confirming the existence of inherent compensatory mechanisms to maintain overall balance; no significant differences were found among asymptomatic, symptomatic, and surgically treated patients. The C-7 slope is a useful marker of overall sagittal alignment, acting as a link between the occipitocervical and thoracolumbar spine.

scholarly journals Relationship of T1 Slope with sagittal alignment parameters of the upper and subaxial cervical spine in patients with cervical lordotic and kyphotic curvature

2020 ◽  
Author(s):  
Dong Sun ◽  
Peng Liu ◽  
Zhaolin Wang ◽  
Jie Cheng ◽  
Jianhui Mou ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Sagittal Alignment ◽  
Pearson Correlation ◽  
Linear Regression Analysis ◽  
Observer Agreement ◽  
Group Differences ◽  
Cervical Lordosis ◽  
Cervical Alignment ◽  
T1 Slope ◽  
Subaxial Cervical Spine

Abstract Background: To identify the relationship between T1 slope and the sagittal alignment parameters of the upper and subaxial cervical spine in patients with cervical lordosis and kyphosis.Methods: Relevant sagittal radiographic parameters pertaining to patients with non-specific neck pain but with no associated neurogenic symptoms were retrospectively analyzed. Patients were categorized into lordotic alignment and kyphotic alignment groups based on the C2-C7 Cobb. Correlation among radiographic variables was assessed with the Pearson correlation coefficient and linear regression analysis. Between-group differences with respect to cervical alignment parameters were assessed with One-way Analysis of Variance.Results: Intra-observer and inter-observer agreement (two independent observers) was rated as excellent (kappa: 0.91 - 0.93). Inter-observer agreement for the two independent observers was rated as and substantial (kappa: 0.79 - 0.80), respectively. Significant between-group differences were observed with respect to C0-C1 angle, C1-C2 angle, C0-C2 angle, C2-C7 SVA (sagittal vertical axis) and TS-CL (T1 slope minus cervical lordosis) (P<0.01 for all), but not with respect to T1S (T1 slope) (P=0.367). In both groups, C2-C7 SVA showed a significant linear correlation with T1S (r2=0.712 vs. r2=0.467) and TS-CL (r2=0.810 vs. r2=0.248).Conclusion: This study showed that the two cervical alignment types (lordosis and kyphosis) have different angular variation in upper and subaxial cervical spine. With the increase in T1 slope, the upper cervical C0-C2 Cobb angle and the C2-7 SVA in the lordotic group were significantly higher than that of the kyphotic group. TS-CL mismatch may significantly impact lordotic cervical alignment in patients with lordosis.

scholarly journals Morphometric study of cervical spine vertebrae in eastern region Nepalese population

2014 ◽  
Vol 11 (3) ◽  
pp. 224-228 ◽  
Author(s):  
S Singh ◽  
M Balakrishnan
Keyword(s):  
Cervical Spine ◽  
Vertebral Body ◽  
Indian Population ◽  
Morphometric Study ◽  
Eastern Region ◽  
Lateral Projection ◽  
Body Diameter ◽  
Canal Diameter ◽  
The Mean ◽  
Tube Distance

Objective: To ascertain the normal values of mid-sagittal vertebral body Diameter, mid-sagittal canal diameter and canal-body ratio in adult Nepalese population. Methods: In this consent based descriptive, clinico -radiological study of 100 individuals who volunteered to being subjected to lateral projection radiographs of cervical spine. The sagittal canal diameter (CD), sagittal vertebral body diameter (VBD) and the canal-body ratio (CBR) was recorded on lateral projection radiographs (film to tube distance at 183 cms) and analyzed statistically. Results: The mean vertebral body diameter was 17.81±1.73mm (male:18.30±1.64mm;female:17.05±1.61mm), mean canal diameter was 17.18±1.67mm (males:17.31±1.74mm; females: 16.97±1.56mm),the mean canal body ratio was 0.97±0.13 (males:0.95±0.13; females:1.00±0.13). In mongoloids mean body diameter is 18.23±1.58 mm, mean canal diameter is 16.87±1.77 mm. and mean canal body ratio is 0.93±0.13. In non-mongoloids the mean body diameter was 17.48±1.79 mm, mean canal diameter was 17.42±1.59 mm, and mean canal body ratio was 1.00±0.13. Conclusion: The vertebral body diameter was significantly larger in men as compared to women, and this difference was statistically significant at all vertebral levels (p <0.05). The canal diameter was more in males than females but this difference was not statistically significant (p >0.05). The canal body ratio was greater in females than in males at all levels but this was also not statistically significant (p >0.05. The canal diameter was more in non-mongoloids as compared to mongoloids but this difference was not significant except at C2 level. Population in the eastern region of Nepal had values more nearer to Indian population but lesser than Europeans. DOI: http://dx.doi.org/10.3126/hren.v11i3.9636 Health Renaissance 2013;11(3):224-228

scholarly journals How the neck affects the back: changes in regional cervical sagittal alignment correlate to HRQOL improvement in adult thoracolumbar deformity patients at 2-year follow-up

2015 ◽  
Vol 23 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Themistocles S. Protopsaltis ◽  
Justin K. Scheer ◽  
Jamie S. Terran ◽  
Justin S. Smith ◽  
D. Kojo Hamilton ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Partial Correlation ◽  
Sagittal Alignment ◽  
Patient Questionnaire ◽  
Partial Correlation Analysis ◽  
Cervical Alignment ◽  
Cervical Sagittal Alignment ◽  
Sagittal Parameters ◽  
Clinical Measures

OBJECT Regional cervical sagittal alignment (C2–7 sagittal vertical axis [SVA]) has been shown to correlate with health-related quality of life (HRQOL). The study objective was to examine the relationship between cervical and thoracolumbar alignment parameters with HRQOL among patients with operative and nonoperative adult thoracolumbar deformity. METHODS This is a multicenter prospective data collection of consecutive patients with adult thoracolumbar spinal deformity. Clinical measures of disability included the Oswestry Disability Index (ODI), Scoliosis Research Society-22 Patient Questionnaire (SRS-22), and 36-Item Short-Form Health Survey (SF-36). Cervical radiographic parameters were correlated with global sagittal parameters within the nonoperative and operative cohorts. A partial correlation analysis was performed controlling for C-7 SVA. The operative group was subanalyzed by the magnitude of global deformity (C-7 SVA ≥ 5 cm vs < 5 cm). RESULTS A total of 318 patients were included (186 operative and 132 nonoperative). The mean age was 55.4 ± 14.9 years. Operative patients had significantly worse baseline HRQOL and significantly larger C-7 SVA, pelvic tilt (PT), mismatch between pelvic incidence and lumbar lordosis (PI-LL), and C2-7 SVA. The operative patients with baseline C-7 SVA ≥ 5 cm had significantly larger C2-7 lordosis (CL), C2-7 SVA, C-7 SVA, PI-LL, and PT than patients with a normal C-7 SVA. For all patients, baseline C2-7 SVA and CL significantly correlated with baseline ODI, Physical Component Summary (PCS), SRS Activity domain, and SRS Appearance domain. Baseline C2-7 SVA also correlated with SRS Pain and SRS Total. For the operative patients with baseline C-7 SVA ≥ 5 cm, the 2-year C2-7 SVA significantly correlated with 2-year Mental Component Summary, SRS Mental, SRS Satisfaction, and decreases in ODI. Decreases in C2-7 SVA at 2 years significantly correlated with lower ODI at 2 years. Using partial correlations while controlling for C-7 SVA, the C2-7 SVA correlated significantly with baseline ODI (r = 0.211, p = 0.002), PCS (r = −0.178, p = 0.009), and SRS Activity (r = −0.145, p = 0.034) for the entire cohort. In the subset of operative patients with larger thoracolumbar deformities, the change in C2-7 SVA correlated with change in ODI (r = −0.311, p = 0.03). CONCLUSIONS Changes in cervical lordosis correlate to HRQOL improvements in thoracolumbar deformity patients at 2-year follow-up. Regional cervical sagittal parameters such as CL and C2–7 SVA are correlated with clinical measures of regional disability and health status in patients with adult thoracolumbar scoliosis. This effect may be direct or a reciprocal effect of the underlying global deformities on regional cervical alignment. However, the partial correlation analysis, controlling for the magnitude of the thoracolumbar deformity, suggests that there is a direct effect of cervical alignment on health measures. Improvements in regional cervical alignment postoperatively correlated positively with improved HRQOL.

scholarly journals Use of Bivector Traction for Stabilization of the Head and Maintenance of Optimal Cervical Alignment in Posterior Cervical Fusions

2017 ◽  
Vol 7 (3) ◽  
pp. 227-229 ◽  
Author(s):  
Isaac O. Karikari ◽  
David B. Bumpass ◽  
Jeffrey Gum ◽  
Patrick Sugrue ◽  
Todd M. Chapman ◽  
...  
Keyword(s):  
Sagittal Alignment ◽  
Intraoperative Complications ◽  
Demographic Data ◽  
Case Series ◽  
Cervical Lordosis ◽  
Consecutive Case ◽  
Vertical Alignment ◽  
Cervical Sagittal Alignment ◽  
Novel Method ◽  
The Mean

Study Design: Retrospective analysis of consecutive case series. Objective: To introduce a novel method of stabilizing the cranium using bivector traction in posterior cervical fusions. Methods: A retrospective review of 50 consecutive patients undergoing instrumented posterior cervical arthrodesis was performed. All patients had at least 3 levels of subaxial fusion using the bivector traction apparatus. Patients’ demographic data was recorded for the following: pre- and postoperative cervical lordosis, pre- and postoperative cervical sagittal vertical alignment (cSVA), and intraoperative complications from pin placements. Results: A total of 50 patients were studied. There were 31 females and 19 males. The mean age at the time of surgery was 49 years (range 35-79). A mean 5.8 levels were fused. The most common levels fused were C2-T3 in 14 patients followed by C2-T2 in 7 patients. In no case did the surgeon or assistant have to scrub out to adjust the alignment. The mean pre- and postoperative cervical lordosis was −6.0° and −10°, respectively ( P = .04). The mean pre-and postoperative cSVA was 30.5 mm and 32 mm, respectively ( P = .6). There were no complications related to placement of the Gardner-Well tongs. Conclusion: The bivector traction is an easy, safe, and effective method of stabilizing the head and obtaining adequate cervical sagittal alignment.

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