Alignment In Asymptomatic Adults Research Articles

Correlation between the cervical sagittal alignment and spine - pelvic sagittal alignment in asymptomatic adults.

BackgroundAlthough there are studies that adequately document the linear correlation between pelvic incidence (PI), sacral slope, lumbar lordosis, and thoracic kyphosis, few have analyzed the pelvic-spine correlation including the cervical spine.Methods:This is a cross-sectional study, wherein the cervical spine was evaluated using radiography and computed tomography (CT) scans, the lumbosacral spine and the pelvis was evaluated using radiography, in adult patients without spinal pathology. Using the Surgimap tool, cervical and spinopelvic parameters were calculated by several investigators. To evaluate the correlation between cervical and spinopelvic parameters, Spearman's coefficient was calculated. To evaluate the concordance correlation of the measured parameters of cervical sagittal alignment on tomography and conventional radiography, Lin's coefficient was calculated and Bland–Altman plots were performed.Results:A total of 51 healthy adults were included in a follow-up from January 2019 to December 2020. Cervical sagittal alignment and sagittal spinopelvic alignment were assessed using radiography, and a correlation was observed between T1 slope (T1S) and lumbar mismatch (coefficient of 0.28, P = 0.047). Then, cervical sagittal alignment was evaluated using CT and sagittal spinopelvic alignment using radiography, and no correlation was observed between PI and thoracic inlet angle or cervical mismatch with lumbar mismatch.Conclusion:In asymptomatic patients, in whom cervical sagittal alignment and spinal-pelvic alignment were evaluated, only a positive correlation was found between lumbar mismatch and T1S, which lacks clinical significance. No concordance was identified between lumbar mismatch and cervical mismatch. Therefore, it is inferred that there is an independence between the sagittal spine-pelvic alignment with respect to the sagittal cervical alignment.

Correlations between the inflection point and spinal sagittal alignment in asymptomatic adults.

The purposes of this study were to analyse the correlations between the inflection point (IP) and spinal sagittal parameters and to establish the corresponding linear regressions in asymptomatic adults. A total of 205 asymptomatic subjects older than 18years were recruited between April 2017 and September 2019. A full-spine, standing X-ray was collected for each subject. The following parameters were documented: the IP, the apices of thoracic kyphosis (TKA) and lumbar lordosis (LLA), the distance between the plumb line of the thoracic apex (TAPL) or lumbar apex (LAPL) and gravity plumb line, thoracic kyphosis (TK), lumbar lordosis (LL) and the upper arc and the lower arc of lumbar lordosis (LLUA and LLLA, respectively). The correlations between the IP and the above parameters and between the thoracic and lumbar parameters were analysed. The level of significance was P < 0.05. The IP was statistically correlated with age (rs = 0.327), the TKA (rs = 0.639), the TAPL (rs = 0.338), TK (rs = 0.391), the LLA (rs = 0.545), the LAPL (rs = - 0.383), the LLUA (rs = 0.371) and the LLLA (rs = - 0.145) but was not linked with LL (rs = 0.118). In addition, there were relationships between the TKA and LLA (rs = 0.397), the TAPL and LAPL (rs = - 0.357), TK and LL (rs = 0.529), TK and the LLUA (rs = 0.742) and TK and the LLLA (rs = 0.148). The IP was significantly related to spinal sagittal alignment in asymptomatic adults. Moreover, predictive formulae for sagittal parameters as a function of the IP were developed, which are helpful for surgeons in comprehending the regulatory mechanisms of spinal sagittal alignment and designing an ideal therapeutic plan. These slides can be retrieved under Electronic Supplementary Material.

2020 Young Investigator Award Winner: Age- and Sex-related Normative Value of Whole-body Sagittal Alignment Based on 584 Asymptomatic Chinese Adult Population From Age 20 to 89.

A cross-sectional radiographic study. The aim of this study was to establish the age- and sex-related normative values of whole-body sagittal alignment in asymptomatic Chinese adult population, and to investigate the changes and possible associated compensation mechanisms across age groups. Previous studies have reported normative data for sagittal spinal alignment in asymptomatic adults. However, there was a lack of comprehensive investigation on age- and sex-related normative values of whole-body sagittal alignment. A total of 584 asymptomatic Chinese adults aged 20 to 89 years were recruited. Subjects were grouped according to age and sex. Whole-body standing radiographs were acquired for evaluating sagittal alignment from spine to lower limb. Comparisons of sagittal parameters between sex in different age groups were performed by independent t test. Pearson correlation analysis was used to determine relationships between each parameter. Mean values of each sagittal parameter were presented based on age and sex. Thoracic kyphosis showed steady increasing trend while lumbar lordosis gradual decrease in both sexes. Pelvic tilt (PT) in males is greater than in females across all age groups with age-related gradual increase. There were significant differences between males and females from 20 to 60 years in terms of KneeFlex angle (KA) and AnkleFlex angle, but the differences were not significant after 60s. T1 pelvic angle (TPA) was significantly correlated with spinal, pelvic and lower-limb alignment. The older group (≥50 years) had a stronger correlation of TPA with PT and KA, whereas the younger (<50 years) had stronger correlation with TK. This study presented a comprehensive study of whole-body sagittal alignment based on a large asymptomatic population, which could serve as an age- and sex-specific reference value for spine surgeons when planning for correction surgery. Age can influence the recruitment of compensation mechanism that involves more pelvic and lower limb mechanisms for elderly people. 3.

Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P95. Quantitative age-adjusted targets for ideal cervicothoracic sagittal alignment in asymptomatic adults

BACKGROUND CONTEXT Recent research has identified increased C2-T3 angle as a risk factor for persistent sagittal malalignment following thoracolumbar surgery. Despite this, no ideal cervicothoracic alignment thresholds exist in the literature. As several studies have demonstrated a clear relationship between the normal aging spine and sagittal spinal alignment, such ideal-alignment thresholds should also account for patient age. PURPOSE This study proposes age-specific cervicothoracic alignment targets using previously published age-specific normative Neck Disability Index (NDI) values. STUDY DESIGN/SETTING Single center retrospective review. PATIENT SAMPLE A total of 223 patients with available biplanar full-body stereographic x-rays. OUTCOME MEASURES C2-T3 lordosis; Neck Disability Index score. METHODS Patients >18 years with cervical sagittal vertical axis RESULTS Overall, 223 patients (50±20years, 65% F) met inclusion criteria, presenting with a mean sagittal vertical axis (SVA) of 17.8±47.7 mm, cervical SVA 19.8±11.2 mm, T1 Slope-C2-C7 lordosis 24.7°±16.2°, and C2-T3 of 2.1°±16.5°. At baseline, increased C2-T3 angle was significantly correlated with both NDI score (r=0.266, p 75 years: 27.8. Liner regression analysis showed a significant relationship between NDI score, age, and baseline cervicothoracic alignment, as assessed by C2-T3 angle (r=0.497, p 75 years: 6.7°. CONCLUSIONS Significant relationships exist between age, neck disability, and cervicothoracic alignment, suggesting broad measurements across the cervicothoracic junction may be clinically relevant in predicting postoperative outcomes of surgical spine deformity patients. Taking into account patient age and USA-normative values of neck disability, this study offers a set of ideal age-adjusted alignment targets for C2-T3. By proposing a set of normative, age-specific cervicothoracic alignment targets, this study better facilitates individual optimization of surgical planning.

Factors determining cervical spine sagittal balance in asymptomatic adults: correlation with spinopelvic balance and thoracic inlet alignment

Background contextBased on the previous studies, cervical lordosis (CL) is a parameter influenced by thoracic kyphosis (TK); however, the correlations still remain unclear. Few studies have analyzed the correlations between the cervical spine lordosis and global spinopelvic balance. To date, there has been no study focused on the factors determining cervical spine sagittal balance. Patient sampleSeventy-seven asymptomatic volunteers without the history of symptoms related to whole spine. Outcome measuresStatistical significance of correlations of radiographic parameters on cervical spine and whole-spine standing lateral radiograph. PurposeTo analyze the factors determining cervical spine sagittal balance, including global spinopelvic balance and thoracic inlet (TI) alignment in asymptomatic adults. Study designA prospective radiographic study. MethodsCervical and whole-spine standing lateral radiographs were taken to analyze the following parameters: spinopelvic parameters pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), and TK; TI parameters thoracic inlet angle (TIA) and T1 slope; and cervical spine parameters C0–C2, C2–C7, and C0–C7 angles and cervical tilting. Statistical analysis was performed using the Pearson correlation coefficients and multiple regression analysis. ResultsAll the parameters showed a normal distribution. There was a significant sequential linkage between PI and SS (r=0.653), SS and LL (r=0.807), LL and TK (r=−0.516), and TK and C0–C7 angle (r=−0.322). There was a significant relationship between TK and T1 slope (r=0.351) but no significant relationship between TK and TIA. There were significant sequential relationships between TIA and T1 slope (r=0.694), T1 slope and C2–C7 angle (r=−0.624), and C2–C7 and C0–C2 angles (r=−0.547). T1 slope was the only parameter that demonstrated a significant correlation with both SP and TI parameters. A linear regression model showed that T1 slope had a stronger relationship with TIA (r=0.694) than TK (r=0.351). ConclusionsT1 slope was a key factor determining cervical spine sagittal balance. Both spinopelvic balance and TI alignment have a significant influence on cervical spine sagittal balance via T1 slope, but TIA had a stronger effect than TK. An individual with large T1 slope required large CL to preserve physiologic sagittal balance of the cervical spine. The results of the present study could serve as baseline data for further studies on the cervical spine sagittal balance in various clinical conditions including the surgical reconstruction of lordosis.

Neutral upright sagittal spinal alignment from the occiput to the pelvis in asymptomatic adults: a review and resynthesis of the literature

An increasing emphasis is being placed on the preservation or restoration of neutral upright sagittal spinal alignment in both deformity surgery and routine spinal operations. Sagittal spinal alignment is becoming recognized as an important predictor of a patient's outcome after spinal surgery. In this literature review, the authors analyze data obtained from previously published studies conducted to evaluate neutral upright sagittal spinal alignment from the occiput to the pelvis in asymptomatic adults. A review of the English-language literature was conducted to identify studies conducted to evaluate neutral upright sagittal spinal (occiput-pelvis) alignment in asymptomatic adult volunteers with no spinal disease. The authors identified 12 articles that met the strict primary inclusion criteria of the current study. From these articles, 23 angles and displacements were selected to depict neutral upright sagittal occiput-pelvis alignment. Pooled estimates of the mean and variance were calculated for angles and displacements that met secondary inclusion criteria. The greatest variation in the regional spinal curves occurred in the cervical spine from C-2 to C-7, whereas the greatest focal angulation in the spine occurred from L-4 to S-1. Sagittal spinal balance was maintained in a narrow range for alignment of the spine over the pelvis and femoral heads. Neutral upright sagittal occiput-pelvis alignment in asymptomatic adults has been well studied regionally. Despite a wide variation in the undulating lordotic and kyphotic regional curves from the occiput to the pelvis, sagittal spinal balance is maintained in a narrower range for alignment of the spine over the pelvis and femoral heads.