Increase In Sagittal Vertical Axis Research Articles

The influence of osteoporotic vertebral fractures on global sagittal alignment in elderly patients: a systematic review and meta-analysis.

Thoracic kyphosis, or loss of lumbar lordosis, is often equated with osteoporosis because vertebral fractures are assumed to be a major causative factor, in addition to degeneration related to age. Despite the few studies aiming to measure the natural change in global sagittal alignment (GSA) that occurs with advancing age, the overall effect of conservatively managed osteoporotic vertebral compression fractures (OVCF) on the GSA in the elderly remains poorly understood. To systematically evaluate the relevant literature regarding the influence of OVCF on the GSA compared to patients of similar age without fractures using the following radiological parameters: Pelvic Incidence (PI), Pelvic Tilt (PT), Lumbar Lordosis (LL), Thoracic Kyphosis (TK), Sagittal Vertical Axis (SVA) and Spino-sacral Angle (SSA). A systematic review of the English language literature dating up until October 2022, was undertaken utilizing the PRISMA guidelines. Of a total of 947 articles, 10 studies met the inclusion criteria (4 Level II, 4 level III and 2 level IV evidence) and were subsequently analyzed. Overall, 584 patients (8 studies) of mean age 73.7years (69.3-77.1) had acute OVCF of one or more vertebra that were managed conservatively. The male to female ratio was 82:412. Five studies mentioned the number of fractured vertebrae, with a total of 393 in 269 patients (average of 1.4 fractured vertebrae per patient). Their pre-operative radiological parameters on standing X-rays showed a mean PI of 54.8°, PT 24°, LL 40.8°, TK 36.5°, PI-LL 14°, SVA 4.8cm, and SSA 115°. In addition, 437 patients were used as a control group with osteoporosis without fractured vertebrae, (6 studies) with an average age of 72.4years (67-77.8) and male to female ratio of 96:210 (5 studies). They all had upright X-rays to assess their global sagittal alignments. Radiological parameters showed an average PI of 54.3°, PT 17.3°, LL 43.4°, TK 31.25°, PI-LL 10.95°, SVA 1.27cm and SSA 125°. A statistical analysis comparing the OVCF group with the control group (4 studies), showed a significant increase in PT of 5.97° (95%CI 2.63, 9.32; P < 0.0005), a significant increase in TK by 8.28° (95%CI 2.15, 14.4; P < 0.008), an increase in PI-LL by 6.72° (95%CI 3.39, 10.04; P < 0.0001), an increase in SVA by 1.35cm (95%CI 0.88, 1.83; P < 0.00001), and a decrease in SSA by 10.2° (95%CI 10.3, 23.4; P < 0.00001). Osteoporotic vertebral compression fractures managed conservatively appear to be a significant causate factor of global sagittal imbalance.

Comparison Between Sagittal Balance Outcomes After Corpectomy, Laminectomy, and Fusion for Cervical Spondylotic Myelopathy: A Matched Cohort Study.

Cervical spondylotic myelopathy (CSM) can be successfully decompressed via either anterior cervical corpectomy and fusion (ACCF) or posterior laminectomy with fusion (LMF). However, few studies have compared the isolated effect of both techniques on cervical sagittal balance, a surrogate end point for clinical outcomes.We aimed to compare the sagittal balance radiological outcomes of ACCF against LMF. A case-matched controlled study of radiological cervical alignment parameters (C0-2, C2-3, index angles, T1 slope, and sagittal vertical axis (SVA)) in two groups of patients was performed by using pre- and postoperative neutral cervical X-rays.In total, 34 patients were enrolled (ACCF n = 17; LMF n = 17). The mean preoperative C2-7 angle was similar (11.58 ± 16.00° for ACCF; 13.36 ± 12.21° for LMF) in both cohorts. Both led to a loss of lordosis (-2.68 ± 13.8°, p = 0.43; -2.94 ± 11.5°, p = 0.31, respectively). At the C0-2, the two operations induced opposite variations (-0.9 ± 8.0°, p = 0.709 for ACCF; 3.5 ± 15.4°, p = 0.357 for LMF). ACCF led to a significant increase in SVA (7.1 ± 11.9 mm, p = 0.002). The C2-3 disk angle more pronouncedly increased with LMF.Both techniques show an equivalent kyphotic effect, with a greater disadvantage for ACCF. The negative impact on SVA changes is greater with ACCF. Both affect the C0-2 unit, with a tendency for kyphosis with ACCF and one for lordosis with LMF. When choosing the appropriate decompression and fusion technique, preoperative sagittal balance parameters should be included in the decision-making process.

Cervical alignment in the obese population following posterior cervical fusion for cervical myelopathy

Study designRetrospective cohort study ObjectiveThe aim of this study was to investigate the effect of body mass index (BMI) on the reoperation rate and cervical sagittal alignment of patients who underwent posterior cervical decompression and fusion for cervical spondylotic myelopathy (CSM). Summary of background dataCervical sagittal balance has been correlated with postoperative clinical outcomes. Previous studies have shown worse postoperative sagittal alignment and higher reoperation rates in patients with high BMI undergoing anterior decompression and fusion. Similar evidence for the impact of obesity in postoperative sagittal alignment for patients with (CSM) undergoing posterior cervical decompression and fusion (PCF) is lacking. MethodsA retrospective analysis of 198 patients who underwent PCF for cervical myelopathy due to degenerative spine disease was performed. Demographics, need for reoperation, and perioperative radiographic parameters were collected. Cervical lordosis (CL), C2–7 sagittal vertical axis (SVA), and T1 slope (T1S) was measured on standing lateral radiographs. Comparative analysis of the patient cohort was performed by stratifying the sample population into three BMI categories (<25, 25–30, ≥30). ResultOf the 198 patients that met inclusion criteria, 53 had BMI normal (<25), 65 were overweight (25−30), and 80 were obese (≥30). Mean SVA increased postoperatively in all groups, 4 mm in the normal group, 13 mm in the overweight group, and 13 mm in the obese group (p = 0.003). There was no significant difference in the postoperative change of cervical lordosis or T1 slope between the groups. Multivariate analysis demonstrated fusions involving the cervicothoracic junction and those involving 5 or more levels significantly affected alignment parameters. There were 27 complications requiring reoperation (14%) with no significant differences among the groups stratified by BMI (p = 0.386). ConclusionsOverweight patients (BMI>25) with CSM undergoing PCF had a greater increase in SVA than normal weight patients while reoperation rates were similar. In addition, preoperative CL increased with increasing BMI, although this trend was not Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation significant and there was not found to be a significant difference between the change in CL from baseline to post-fusion between BMI cohorts. This study further highlights the importance of considering BMI when attempting to optimize sagittal alignment in patients undergoing PCF.

Multilevel, Percutaneous Posterior Cervical Interfacet Distraction and Fusion for Cervical Spondylotic Radiculopathy: Clinical and Radiographic Outcomes.

Retrospective review of patients who underwent multilevel posterior cervical interfacet distraction and fusion (PCIDF) using cages for cervical spondylotic radiculopathy (CSR). To determine clinical and radiographic outcomes following multilevel PCIDF. Anterior cervical discectomy and fusion has long been the standard of treatment for CSR. Advancements in surgery have employed minimally invasive techniques such as endoscopic discectomy, foraminotomy, and PCIDF. Studies on single-level PCIDF have reported good clinical outcomes, short hospital stays, and rare complications, but its application in multilevel disease is still evolving. Patients with CSR and confirmed radiologic evidence of multilevel foraminal stenosis without central canal stenosis were reviewed. Two-year outcomes of multilevel PCIDF included Neck Disability Index, neck and arm Visual Analogue Scale (VAS), radiographic cervical alignment parameters, evidence of fusion, and incidence of adjacent segment degeneration were compared at different time points. Thirty patients (mean age 54.6 ± 8.3) were included in the study with an average of 3.4 ± 0.8 levels treated. Mean surgical duration and intraoperative blood loss was 143.2 ± 69.7 minutes and 27.7 ± 28.7 mL, respectively, with an average length of stay at 1.8 ± 1.5 days. Neck Disability Index, VAS-neck, and VAS-arm all significantly improved at 2 weeks (P < 0.001) and was maintained until 2 years postoperatively. A significant decrease in segmental and C2-C7 lordosis, with a corresponding increase in sagittal vertical axis, was observed at 3 months postoperatively (P < 0.001) but did not deteriorate further on subsequent visits. Successful fusion was achieved in 90% of patients after 2 years. There was a 13.3% incidence of adjacent segment degeneration in the study cohort and one perioperative complication (3.3%). Our study suggests that multilevel PCIDF is safe and effective for CSR caused by foraminal stenosis. However, its potential to cause kyphosis and clinical impact on global sagittal alignment requires further scrutiny and long-term evaluation.Level of Evidence: 4.

Characteristics of sagittal spine alignment in female patients with distal radius fractures due to fall

ObjectivesDistal radius fractures occur due to reflex clasp when falling. Recently, attention has been focused on the strong relationship between sagittal spine alignment and falls. Therefore, we investigated the parameters of sagittal spinal alignment in distal radius fractures in female patients. Patients and methodsThe subjects were group D: 28 female patients with distal radius fractures aged 50 years or older (mean age: 69.3 years), and group C: 26 healthy female patients without a history of fragility fractures (mean age: 70.5 years). Height, body weight, and body mass index (BMI) were measured as physical indices. As parameters of sagittal spinal alignment, the sagittal vertical axis (SVA), pelvic tilt (PT), pelvic incidence (PI), sacral slope (SS), lumber lordosis (LL), and thoracic kyphosis (TK) were measured on lateral whole-spine plain radiographs in a standing position. The measured physical indices and sagittal spinal alignment parameters were compared between groups. ResultsHeight, weight, and BMI did not differ significantly between the two groups. Among the sagittal spinal alignment parameters, PT, PI, SS, LL, and TK did not differ significantly between groups, whereas SVA was significantly higher in group D than in group C (P < 0.05). ConclusionIn this study, SVA was significantly higher in group D than in group C. As SVA increased, the center of gravity of the body shifts forward, which can cause the body to lose balance and fall. This study suggested that an increase in SVA is associated with distal radius fractures.

Impact of the Inclusion of C2 in Posterior Cervical Fusions for Cervical Myelopathy on Sagittal Cervical Alignment.

Retrospective cohort study. To determine the impact of including C2 in posterior fusions on radiographic parameters of cervical alignment in cervical spondylotic myelopathy. Despite the use of posterior instrumentation and arthrodesis after cervical laminectomy, loss of lordosis and the development of kyphosis are prevalent. Inadequate cervical lordosis and other measures of sagittal cervical alignment have been shown to correlate with disability, general health scores, and severity of myelopathy. The role of C2 in the posterior tension band, which maintains sagittal alignment, differs from the subaxial spine, as it is the insertion point for erector spinae muscles that play a critical role in maintaining posture. This study compares the radiographic outcomes of sagittal balance between 2 cohorts of patients who underwent posterior cervical decompression and fusion for cervical myelopathy over a 12-year period at a single institution. Demographic and surgical characteristics were collected using the electronic medical record of patients undergoing posterior cervical fusions (PCF) which included the axis [axial fusion (AF)] and those that were subaxial fusions (SAF). Radiographic measurements included preopertaive and postoperative C2-C7 lordosis (CL), C2-C7 sagittal vertical axis (SVA), and T1 slope (T1S). After review of the electronic medical records, 229 patients were identified as having PCF and decompression for treatment of myelopathy. One hundred sixty-seven patients had AF, whereas 62 had SAF. PCF resulted in loss of CL in both cohorts. Although there was no statistical difference in postoperative CL, there was a significant increase in SVA (P<0.001) and T1S (P<0.001) with AF. PCF often result in loss of lordosis. When compared with SAF, inclusion of C2 into the fusion construct may result in worsened sagittal balance, increasing the SVA and T1S.

135. Neutral cervical sagittal vertical axis (SVA) varies with T1 tilt

BACKGROUND CONTEXT With an aging population and increasing incidence of cervical spine surgery, more attention is being focused on cervical alignment and deformity. Iatrogenic deformity can result from under- or overcorrection of cervical sagittal alignment during fusion surgery. We sought to explore the relationship between T1 tilt and cervical SVA. In our cadaveric study, the sagittal vertical alignment (SVA) was altered for a given T1 tilt until the least extrinsic force was required to maintain alignment. This correlates with the in vivo state requiring the least muscle contraction to maintain alignment. PURPOSE To determine if an increase or decrease in T1 tilt from baseline will require a compensatory increase or decrease in SVA in order to maintain neutral posture. STUDY DESIGN/SETTING Cadaver biomechanical study. PATIENT SAMPLE Six cadaveric cervical spines (occiput-T1). OUTCOME MEASURES C0-T1 SVA (mm). METHODS Six cadaveric cervical spines (occiput-T1) were mounted with a 5 kg mass simulating head weight. Forces and moments were recorded with a load cell. Motion was recorded with optoelectric sensors placed at each level, and a thin cut CT was used to create a 3-dimensional reconstruction. The head was constrained to maintain horizontal gaze. T1 tilt and SVA were adjusted by rotating or translating the test bed (respectively) to find the condition requiring the least extrinsic force to maintain. T1 tilt was then decreased, and SVA was adjusted to minimize extrinsic force and measured. T1 tilt was then increased and SVA adjusted and measured. RESULTS T1 tilt was decreased an average of 6.49 ± 1.39° (mean ± SD) from baseline, requiring a decrease in C0-T1 SVA of 28.14 ± 17.41 mm to achieve neutral posture. T1 tilt was increased 35.12 ± 37.08° from baseline, leading to an increase in SVA of 8.80 ± 2.72 mm. CONCLUSIONS As T1 tilt was increased from baseline, an increase in C0-T1 SVA was required to maintain neutral posture. As T1 tilt was decreased, a decrease in SVA was required. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Adult spinal deformity and its relationship with hip range of motion: a cohort study of community-dwelling females

BACKGROUND CONTEXTAdult spinal deformity affects lower extremity alignment with compensation in joint range of motion (ROM) and alignment of the hip. PURPOSETo investigate the relationship between sagittal spinopelvic alignment and the ROM of the hip joint and the femoral oblique angle (FOA). STUDY DESIGNCross-sectional, observational cohort study of community-dwelling Japanese women. METHODSThe study group included 158 women, enrolled in our ongoing prospective cohort study, with upright spine radiographs and physical measurements obtained for all participants. Radiographic spinopelvic parameters included measurement of thoracic kyphosis, lumbar lordosis (LL), sagittal vertical axis (SVA), sacral slope, pelvic incidence, and pelvic tilt (PT). FOA parameters were measured on hip radiographs and hip ROM included external and internal rotation and extension. The association between spinopelvic parameters, the FOA, and hip joint ROM was evaluated using Spearman's correlation analysis. RESULTSExternal rotation of the hip was correlated with LL (R=0.179, p=.024), PT (R=−0.273, p=.001) and SVA (R=−0.215, p=.007), with the FOA being correlated with the SVA (R=0.502, p<.001). CONCLUSIONSThe decrease in hip external rotation with adult spinal deformity might reflect a structural modification in spinopelvic alignment. An increase in FOA was associated with an increase in SVA, indicative of a sagittal malalignment in the decompensated phase of adult spinal deformity.

Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters

BACKGROUND CONTEXT Proximal junctional kyphosis (PJK) is a significant concern following long posterior spinal fusion. Biomechanically, proximal hook placement at the upper instrumented vertebra have been shown to allow a more gradual transition to normal motion compared with pedicle screws in a long posterior instrumented spinal fusion. PURPOSE The purpose of this study was to evaluate the risk of developing proximal junctional kyphosis with sublaminar hooks versus pedical screw fixation at the upper instrumented vertebra of a posterior spine fusion for adult spinal deformity. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE Consecutive patients who underwent elective posterior spinal fusion for adult deformity at a single academic institution from 2008 to 2014 with a minimum of 2years of follow-up were identified. Patients with proximal hooks and those with proximal screws were separated into 2 groups. OUTCOME MEASURES Preoperative, first postoperative, and final postoperative standing radiographs were reviewed. Radiographic assessments included: sagittal vertical axis (SVA), pelvic incidence, lumbar lordosis, thoracic kyphosis, T1 pelvic angle (TPA) and kyphosis at one- and two-levels above the upper instrumented vertebra (UIV+1, UIV+2). Two common methods of assessing PJK were used. At two levels above the upper instrumented vertebra (UIV+2), kyphosis greater than 10° and more than a 10° increase from the preoperative film was defined as PJK. At UIV+1, PJK was defined as a greater than 15° increase from the preoperative film. METHODS Multivariate logistic regression was used to test the association between proximal hooks and development of PJK while controlling for differences in patient and operative characteristics. RESULTS A total of 142 patients fulfilled inclusion criteria. Average follow-up was (52.8 ±29.1 months). There were no significant differences in demographic characteristics between the 2 groups. Patients with sublaminar hooks at the UIV presented with significantly fewer instances of PJK using UIV+1 (44.0% vs. 63.1%; p=.029) and UIV+2 (52.0% vs. 76.1%; p=.048) measurements compared to those who received pedicle screws at the UIV. Patients with laminar hooks experienced a significantly greater increase in SVA from preoperative to immediate postoperative (13.6±11.6 mm vs. 1.8±12.4 mm; p CONCLUSIONS Laminar hooks at the upper instrumented vertebra were associated with reduced rates of PJK compared with pedicle screws in patients who undergo deformity-correcting spine fusion for adult spinal deformity. This information may be useful for operative planning to minimize the occurrence of PJK after adult deformity surgery.

Wednesday, September 26, 2018 7:35 AM–9:00 AM ePosters: P17. Regional and segmental changes of the spine from standing to sitting: a chain of compensation

BACKGROUND CONTEXT Regional and segmental changes of the lumbar spine have previously been described as patients transition from standing to sitting, however alignment changes in the cervical and thoracic spine have yet to be investigated. PURPOSE The aim of this study was to assess cervical and thoracic regional and segmental changes in patients with normal spinal pathologies. STUDY DESIGN/SETTING Retrospective review of a single center database of full-body stereoradiographic imaging and clinical data. PATIENT SAMPLE A total of 207 patients with nondegenerative, nondeformity spinal pathology. OUTCOME MEASURES Global alignment parameters: sagittal vertical axis (SVA), PI-LL, PT, TK. Cervical alignment: cSVA, C2–C7 lordosis (CL), T1 slope minus CL (TS-CL). Segmental changes in alignment from C2 to T12 between standing and sitting radiographs. METHODS Patients age >18years old with nondegenerative, nondeformity spinal pathologies. Patients with lumbar degenerative conditions or thoracolumbar deformity were excluded. Sub-analysis was performed of patients with cervical and thoracic segmental measurements. RESULTS A total of 207 patients were included (age 51±16years, BMI 26.7±6 kg/m2). As patients transitioned from standing to sitting, there was an increase in pelvic tilt of 12.2° (11.9°–24.2°), an increase in PI-LL by 22.8° (−7.1°–15.7°), and increase in SVA by 53.3 mm (−4.2 mm to 49.2 mm, all P CONCLUSIONS In this cohort of nondegenerative and nondeformity spine patients, the greatest amount of regional changes occur for cervical lordosis, C2–T3 angle, TK, SVA, and PI-LL as patients transition from standing to sitting position in order to maintain global spinal alignment, with C4–C5 and C5–C6 having the greatest mobility.

Magnitude, Location, and Factors Related to Regional and Global Sagittal Alignment Change in Long Adult Deformity Constructs: Report of 183 Patients With 2-Year Follow-up.

This is a retrospective review of a prospective multicenter adult spinal deformity (ASD) database. To quantify the location and magnitude of sagittal alignment changes within instrumented and noninstrumented spinal segments and to investigate the factors associated with these changes after surgery for ASD. Spinal realignment is one of the major goals in ASD surgery and changes in the alignment are common following surgical correction. Inclusion criteria: operative patients with age above 18, coronal Cobb angle ≥20 degrees, sagittal vertical axis (SVA) ≥5 cm, pelvic tilt ≥25 degrees, and/or thoracic kyphosis ≥60 degrees. revision surgery 6 weeks postoperatively. Standard sagittal radiographic spinal deformity parameters were evaluated. Changes in sagittal parameters between 6 weeks and 2 years postoperatively were assessed within and outside instrumented segments. Associations between changes in sagittal alignment and age, preoperative SVA, rod diameters, rod material, presence of 3-column osteotomy, and the use of interbody fusions were evaluated. Patients were also stratified by >5- and >10-degree changes in alignment. In total, 183 patients (male:29, female:154, average age: 56±14.8 y) met inclusion criteria. A total of 45(24.6%) patients had increase in pelvic tilt >5 degrees, 74(40.4%) had increase in pelvic incidence and lumbar lordosis (LL) >5 degrees, and 76 (41.5%) had increase in SVA >2 cm. Mean change of thoracic sagittal alignment was +8 degrees; 70 (60%) patients had increases of >5 degrees and 31 (27%) had increases of >10 degrees. Noninstrumented thoracic segments had significantly more increase than instrumented thoracic segments (P=0.02). Mean loss of LL was -6 degrees; 49(47%) patients had worsening >5 degrees and 13(13%) >10 degrees. Noninstrumented lumbar segments had significantly less loss of lordosis than instrumented segments (P<0.01). Risks for loss of LL were: age 65 years and above [odds ratio (OR) 9.4; 95% confidence interval (CI), 3.5-25.2; P<0.01], preoperative SVA>5 cm (OR, 2.4; 95% CI, 1.3-4.4; P<0.01), and lumbar interbody fusion (OR, 2.3; 95% CI, 1.2-4.2; P<0.01). Smaller rods (4.5 mm) were associated with a lower probability of worsening LL compared with 5.5-mm rods (OR, 0.15; 95% CI, 0.04-0.58; P<0.01) and 6.0-mm rods (OR, 0.36; 95% CI, 0.18-0.72; P<0.01). The presence of a 3-column osteotomy and rod material were not significant factors in alignment changes (P>0.05). After correction of ASD, increases in thoracic and decreases in lumbar alignment is common. Loss of thoracic sagittal alignment primarily occurs in noninstrumented thoracic segments, whereas instrumented lumbar levels in elderly patients ( above 65 y) with high preoperative SVA, interbody fusions, and larger rods have significantly higher rates of postoperative sagittal alignment changes in the lumbar spine.

Accuracy of preoperative surgical planning software in predicting postoperative alignment in patients undergoing minimally invasive multilevel anterior column reconstruction for positive sagittal balance deformity

BACKGROUND CONTEXT: Sagittal realignment in adult deformity surgery is crucial. Patients can present with an obvious increase in sagittal vertical axis (SVA) or have a hidden sagittal balance problem with a normal SVA but high pelvic tilt (PT) (compensated balance). Software is available to measure patient alignment parameters and to simulate the operation. Anterior column reconstruction using multiple anterior cages inserted via a minimally invasive lateral or anterior technique may provide a reliable way of executing the preoperative plan.

Cervical Lordosis Increases with Age in Adult Spinal Deformity: A Cross-Sectional Study of Nonoperative Patients

Introduction It is theorized that with age and degeneration, the cervical spine becomes progressively more kyphotic; however, there are no studies which support these conclusions. We performed a radiographic analysis of patients with adult spinal deformity (ASD) and hypothesized that cervical lordosis would decrease with aging. Patients and Methods The nonoperative arm of a prospective multicenter database of patients with ASD was analyzed. Inclusion criteria were patients &gt; 18 years old meeting any one of the following criteria: Coronal Cobb &gt; 20 degrees, C7-S1 sagittal vertical axis (SVA) &gt; 5 cm, pelvic tilt (PT) &gt; 25 degrees, or thoracic kyphosis (TK) &gt; 60 degrees, and the patients who did not undergo surgery. Nonidiopathic causes of scoliosis, history of spine surgery, and age &lt; 18 years were excluded. Coronal and sagittal radiographic parameters were collected with particular interest to cervical sagittal parameters. Curves were classified into Schwab type. Age groups were separated into group 1: &lt; 40 years, group 2: 41 to 60 years, and group 3: &gt; 60 years. Statistical analysis was performed with Wilcoxon rank sum test for continuous variables with a p value &lt; 0.05 as significant. Results Of the 491 patients in the database, 373 met inclusion criteria for the study and 269 had complete radiographic data for analysis. With increasing age, there were an overall slight increase in body mass index and a statistically significant increase in the Charlson Comorbidity Index. There were no differences in Schwab curve type prevalence between groups. The mean cervical lordosis (CL) increased with age (1.6 ± 10.6, 7.1 ± 13.3, and 11.8 ± 13.2 in groups 1, 2, and 3, respectively, p = 0.04,&lt; 0.01, and &lt; 0.01. Interestingly, there was a corresponding increase in T1 slope between groups 1, 2, and 3 without an increase in thoracic kyphosis. Meanwhile, the C2–7 SVA remained the same (3.0 ± 1.2, 2.7 ± 1.6, and 2.7 ± 1.8, groups 1, 2, and 3, respectively, p = 0.17, 0.88, 0.32). With increasing age, there was a decrease in lumbar lordosis (LL), increase in PT, and increase in SVA. Conclusion CL actually increases with age in nonoperative ASD patients while the thoracic kyphosis remained the same. The LL decreased whereas the PT and SVA increased. The types of curve distributions were similar between all the age groups.