Changes In Cervical Sagittal Alignment Research Articles

How does cervical sagittal profile change after the spontaneous compensation of global sagittal imbalance following one- or two-level lumbar fusion.

This study aimed to evaluate the cervical sagittal profile after the spontaneous compensation of global sagittal imbalance and analyze the associations between the changes in cervical sagittal alignment and spinopelvic parameters. In this retrospective radiographic study, we analyzed 90 patients with degenerative lumbar stenosis (DLS) and sagittal imbalance who underwent short lumbar fusion (imbalance group). We used 60 patients with DLS and sagittal balance as the control group (balance group). Patients in the imbalance group were also divided into two groups according to the preoperative PI: low PI group (≤ 50°), high PI group (PI > 50°). We measured the spinal sagittal alignment parameters on the long-cassette standing lateral radiographs of the whole spine. We compared the changes of spinal sagittal parameters between pre-operation and post-operation. We observed the relationships between the changes in cervical profile and spinopelvic parameters. Sagittal vertical axis (SVA) occurred spontaneous compensation (p = 0.000) and significant changes were observed in cervical lordosis (CL) (p = 0.000) and cervical sagittal vertical axis (cSVA) (p = 0.023) after surgery in the imbalance group. However, there were no significant differences in the radiographic parameters from pre-operation to post-operation in the balance group. The variations in CL were correlated with the variations in SVA (R = 0.307, p = 0.041). The variations in cSVA were correlated with the variations in SVA (R=-0.470, p = 0.001). Cervical sagittal profile would have compensatory changes after short lumbar fusion. The spontaneous decrease in CL would occur in patients with DLS after the spontaneous compensation of global sagittal imbalance following one- or two-level lumbar fusion. The changes of cervical sagittal profile were related to the extent of the spontaneous compensation of SVA.

Radiographic Risk Factors for Adjacent Segment Disease Following Anterior Cervical Discectomy and Fusion (ACDF): A Systematic Review and Meta-Analysis.

Systematic review and meta-analysis. To assess the radiographic risk factors for adjacent segment disease (ASD) following anterior cervical discectomy and fusion (ACDF) for degenerative cervical spine pathologies. PubMed, Embase and the Cochrane Library databases were searched up to December 2023. The primary inclusion criteria were degenerative spinal conditions treated with ACDF, comparing radiological parameters in patients with and without postoperative ASD. The radiographic parameters included intervertebral disc height, cervical sagittal alignment, sagittal segmental alignment, range of motion, segmental height, T1 slope, sagittal vertical axis (SVA), thoracic inlet angle (TIA), and plate to disc distance (PPD). Risk of bias was assessed for all studies. The Cochrane Review Manager was utilized to perform the meta-analysis. From 7044 articles, 13 retrospective studies were included in the final analysis. Three studies had "not serious" bias and the other 10 studies had serious or very serious bias. The total number of patients in the included studies was 1799 patients. Five studies included single-level ACDF, 2 studies included multi-level ACDF, and 6 studies included single or multi-level ACDF. On meta-analysis, the significant risk factors associated with ASD development were reduced postoperative cervical lordosis (mean difference [MD] = 3.35°, P = .002), reduced last-follow-up cervical lordosis (MD = -3.02°, P = .0003), increased preoperative to postoperative cervical sagittal alignment change (MD = -3.68°, P = .03), and the presence of developmental cervical canal stenosis (Odds ratio [OR] = 4.17, P < .001). Decreased postoperative cervical lordosis, greater change in cervical sagittal alignment and developmental cervical canal stenosis were associated with an increased risk of ASD following ACDF.

Preoperative Cervical Range of Motion in Flexion as a Risk Factor for Postoperative Cervical Sagittal Imbalance After Laminoplasty.

Retrospective study. To investigate factors associated with cervical sagittal imbalance (CSI) after cervical laminoplasty (LMP). Preoperative dynamic cervical sagittal alignment is an important predictor for changes in cervical sagittal alignment and clinical outcomes after LMP. However, the impact of preoperative dynamic cervical sagittal alignment on postoperative changes in the cervical sagittal vertical axis (cSVA) after LMP remains unclear. We hypothesized that preoperative cervical flexion and extension function are associated with the changes in cSVA and clinical outcomes and found potential risk factors for post-LMP CSI. Patients undergoing LMP at a single institution between January 2019 and December 2021 were retrospectively reviewed. The average follow-up period was 19 months. The parameters were collected before the surgery and at the final follow-up. We defined the changes in cSVA (△cSVA) ≤ -10 mm as the improvement group, -10 mm < △cSVA ≤ 10 mm as the stable group, and △cSVA > 10 mm as the deterioration group. Multivariate logistic regression was used to evaluate factors associated with postoperative CSI. The χ 2 test was used to compare categorical data between groups. T tests, analysis of variance, Kruskal-Wallis tests, and Mann-Whitney Wilcoxon tests were used to assess the differences between radiographic and clinical parameters among groups. A receiver operating characteristic curve analysis was used to identify optimal cutoff values. The study comprised 102 patients with cervical spondylotic myelopathy. The Japanese Orthopedic Association recovery rate was better in the improvement group and a significant aggravation in neck pain was observed in the deterioration group after surgery. Cervical Flex range of motion (ROM; spine range of flexion) was significantly higher in the deterioration group. The multivariate logistic regression model suggested that greater Flex ROM and starting LMP at C3 were significant risk factors for postoperative deterioration of cervical sagittal balance. Receiver operating characteristic curves showed that the cutoff value for preoperative Flex ROM was 34.10°. Preoperative dynamic cervical sagittal alignment influences postoperative cervical sagittal balance after LMP. Cervical LMP should be carefully considered for patients with a preoperative high Flex ROM, as CSI is likely to occur after surgery. Level 3.

Resection of Cervical Dumbbell-Shaped Schwannoma Using Posterior Unilateral Approach: Impact on Postoperative Cervical Function and Clinical Outcomes.

A retrospective comparative study. This study aimed to evaluate the radiographical changes in cervical sagittal alignment (CSA) and clinical outcomes after tumor resection using a posterior unilateral approach without spinal fixation for patients with cervical dumbbell-shaped schwannoma (DS). Seventy-three patients with DS who were followed up for at least 2years were included. The Eden classification was used to designate the types of DS. The CSA and range of motion (ROM) were analyzed using radiographs. The clinical outcomes were assessed using the Japanese Orthopaedic Association (JOA) score and JOA cervical myelopathy questionnaire. The CSA in the neutral, flexion, and extension position and cervical ROM were not significantly reduced in the follow-up period. The JOA scores showed significant improvement after surgery. The postoperative radiographic parameters and clinical outcomes of Eden type II or III DS, which needed facetectomy for the resection, did not show any statistically significant difference compared with those of Eden type I tumor, which was resected without facetectomy. Fifty-two cases (71.2%) achieved gross total resection, whereas 21 cases (28.8%) remained in partial resection (PR). One case underwent reoperation due to the regrowth of the remnant tumor whose margin was at the entrance of the intervertebral foramen. Tumor resection using the posterior unilateral approach preserved CSA and resulted in favorable clinical outcomes in patients with DS. When the resection ends in PR, the proximal margin of the remnant tumor should be located distally away from the entrance of the foramen to prevent regrowth.

Description of age-related changes in cervical sagittal alignment based on pelvic incidence classification in asymptomatic Chinese population.

To investigate the pelvic incidence (PI)- and age-related cervical alignment changes of Chinese healthy population. Six hundred and twenty-five asymptomatic adult subjects, who underwent the standing whole spinal radiograph, were recruited in this work. The sagittal parameters were measured, including Occipito-C2 angle (O-C2), C2-7 angle (C2-7), cranial arch, caudal arch, T1-slope (T1S), C2-7 sagittal vertical axis (C2-7 SVA), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic tilt (PT), sacral slope (SS), PI, and sagittal vertical axis (SVA). All subjects were stratified into 5 age groups, namely 40-59years, 60-64years, 65-69years, 70-74years, and 75years and above, with each age group further divided into 2 subgroups based on PI (deeming PI < 50° as low PI, and PI ≥ 50° as high PI). The correlations between PI or age, and other sagittal parameters were assessed. The age-related changes of sagittal parameters in each PI subgroup were also assessed, followed by one-way analysis of variance analysis for change comparison between age groups. The average cervical sagittal parameters were as below: 18.2 ± 6.8° for O-C2, 10.4 ± 10.2° for C2-7, 3.9 ± 7.5° for cranial arch, 6.5 ± 7.1° for caudal arch, 23.6 ± 7.3° for T1S, and 21.0 ± 9.7mm for C2-7 SVA. There was no obvious difference observed between PI and cervical sagittal parameters, excepting for caudal arch. While, C2-7, cranial arch, caudal arch, T1S, and C2-7 SVA increased remarkably with the age. Thereof, C2-7 exhibited great increases at the age of 60-64years and 70-74years, respectively, cranial arch increased notably at 60-64years of age, and caudal arch developed obviously at 70-74years of age, regardless of PI. This study showed the PI- and age-related cervical alignment changes of Chinese healthy population. Based on the classification in our study, high or low PI apparently did not correlate with the occurrence of cervical degenerative disease.

Age-related changes in cervical sagittal alignment: based on 625 Chinese asymptomatic subjects.

This work aimed to provide a comprehensive description of cervical alignment including cranial arch and caudal arch according to age, thus offering a reference database for cervical deformity treatment. Total 150 males and 475 females aged at 48-88 were enrolled from August 2021 to May 2022. Radiographic parameters were measured, including Occipito-C2 angle (O-C2), C2-7 angle (C2-7), cranial arch, caudal arch, T1-slope (T1s), and C2-7 sagittal vertical axis (C2-7 SVA). Pearson correlation coefficient was employed in analyzing associations among sagittal parameters and between age and each parameter. Five groups were set according to different age stages, namely group with age 40-59 (N = 77), group with age 60-64 (N = 189), group with age 65-69 (N = 214), group with age 70-74 (N = 97), and group with age exceeding 75 (N = 48). An analysis of variance (ANOVA) test was applied to compare multi-sets of cervical sagittal parameters (CSPs). Chi-square test or Fisher's exact test was used in assessing the relationships of various cervical alignment patterns with age groups. T1s exhibited the strongest correlation with C2-7 (r = 0.655) and caudal arch (r = 0.561), and moderately correlated with cranial arch (r = 0.355). The positive correlations between age and C2-7 angle (r = 0.189, P < 0.001), cranial arch (r = 0.150, P < 0.001), caudal arch (r = 0.112, P = 0.005), T1s (r = 0.250, P < 0.001), as well as C2-7 SVA (r = 0.090, P = 0.024) were observed. Moreover, two progressive growths of C2-7 were shown after 60-64 and 70-74years old, respectively. Thereof, cranial arch increased greatly after the age of 60-64, followed by a relative stability in the degeneration. The notable growth of caudal arch was observed after the age of 70-74, and the growth remained stable when exceeding the age of 75. The difference between cervical alignment patterns and age groups was obvious (Fisher's exact test P < 0.001). This work explored in detail the normal reference values of cervical sagittal alignment including cranial arch and caudal arch under different age groups. Age-related changes in cervical alignment depended on the increase in the cranial and caudal arches in different proportions with age.

Correlation Between Cervical Spine Sagittal Alignment and Clinical Outcome After Standalone Intersomatic Titanium Cage CeSPACE for Cervical Anterior Discectomy and Fusion in Cervical Degenerative Disk Diseases.

The aim of this study was to determine the relationship between cervical spine sagittal alignment and clinical outcomes after using a standalone intersomatic titanium cage CeSPACE for anterior cervical discectomy and arthrodesis. We present our clinical experience in a group of 180 patients with a mean follow-up for at least 2 years. Patients were evaluated by clinical and radiological assessment preoperatively, immediately after surgery and at regular follow-up. There were 97 male and 83 female patients (average age: 56.6 years) who were preoperatively affected by cervical radiculomyelopathy that was due to spondylosis or cervical disk herniation and who underwent surgical treatment. All patients underwent an anterior discectomy and interbody fusion through the positioning of one or more levels of the CeSPACE device. Compared with the preoperative scores, improvement was seen in postoperative visual analog scale (VAS) scores and Neck Disability Index (NDI) values. The standalone intersomatic titanium cage CeSPACE for anterior cervical discectomy and arthrodesis improved radiculomyelopathy and increased the probability of cervical kyphotic alignment. However, cervical sagittal alignment after surgery was not significantly associated with clinical outcomes in terms of postoperative improvement in VAS scores and NDI values. Similarly, the change in cervical sagittal alignment was not related to visual analog scale scores or Neck Disability Index values.

Relationship Between Syrinx Resolution and Cervical Sagittal Realignment Following Decompression Surgery for Chiari I Malformation Related Syringomyelia Based on Configuration Phenotypes.

Combined with different configuration types of syringomyelia, to analyze the correlation between syrinx resolution and changes in cervical sagittal alignment following Foramen magnum and Magendie dredging (FMMD) for syringomyelia associated with Chiari I malformation (CM-I), and to further explore the respective relationship with clinical outcome. A consecutive series of 127 patients with CM-I and syringomyelia who underwent FMMD in our center met the inclusion criteria of this study. Their clinical records and radiologic data were retrospectively reviewed. The Japanese Orthopedic Association (JOA) scoring system and the Chicago Chiari Outcome Scale (CCOS) were used to evaluate the surgical efficacy. The phenotypes of syringomyelia and the clinical characteristics of the patients were analyzed according to grouping by cervical curvature at baseline. The preoperative straight or kyphotic cervical alignment is more common in the moniliform syrinx. After surgery, the syrinx resolution and cervical sagittal realignment in the moniliform group are more obvious, and the corresponding prognosis is relatively better. Spearman correlation analysis showed that the ΔS/C ratio (the change ratio of syrinx/cord) was positively correlated with the CCOS (p = 0.001, r = 0.897) and ΔC2-7A (the change of lower cervical angle) (p = 0.002, r = 0.560). There was also a correlation between the ΔJOA score (the change rate of the JOA score) and ΔC2-7A (p = 0.012, r = 0.467). After decompression surgery, syrinx resolution may coexist with the changes in the subaxial lordosis angle, especially for syrinx in moniliform type, and the relationship between syrinx resolution and cervical sagittal realignment might be valuable for evaluating the surgical outcome.

Impact of cervical and global spine sagittal alignment on cervical curvature changes after posterior cervical laminoplasty

ObjectiveTo analyze the correlation between the changes in cervical curvature and the sagittal parameters of spino-pelvic and clinical efficacy after posterior laminoplasty (LP).MethodsThe patients with cervical spondylosis treated with LP from June 2018 to December 2020 were reviewed. The preoperative and follow-up spine full-length films were measured. The measured data included C2–C7 Cobb angle, C2–7 sagittal vertical axis (SVA), T1 slope (T1S), pelvic incidence, sacral slope (SS), pelvic tilt (PT), lumbar lordosis (LL), thoracic kyphosis (TK), and C7-SVA. Japanese Orthopaedic Association (JOA) score and neck disability index (NDI) score were recorded before surgery and follow-up.ResultsThere were 56 patients in this study. There were no significant differences in spino-pelvic sagittal parameters before and after surgery; however, the JOA score significantly improved. The changes in postoperative cervical lordosis correlated with SS, PT, LL, T1S, and C7-SVA (P < 0.05). Regression analysis showed that T1S and C7-SVA were associated with reducing cervical lordosis (P = 0.021 and P = 0.001, respectively). Patients with larger T1S combined with larger C7-SVA had more cervical lordosis loss, poor JOA improvement, and high postoperative NDI scores (P < 0.001, P = 0.018, and P < 0.001, respectively).ConclusionPatients should be examined with full-length spine film before surgery to evaluate the cervical and spino-pelvic sagittal balance. T1S and C7-SVA correlated with changes in cervical sagittal alignment after LP.Level of evidenceIII.

Is the Zero-P Spacer Suitable for 3-Level Anterior Cervical Discectomy and Fusion Surgery in Terms of Sagittal Alignment Reconstruction: A Comparison Study with Traditional Plate and Cage System.

The Zero-P spacer was primarily developed aiming to reduce the morbidity associated with the traditional anterior cervical plate. During the past decade, many authors have reported the use of Zero-P spacers for anterior cervical discectomy and fusion (ACDF) of one or two segments. Nevertheless, there is still a paucity of knowledge on the safety and feasibility of using Zero-P spacers for 3-level fixation. The objective of this study was to investigate the clinical and radiological outcomes, with a focus on the sagittal alignment reconstruction of 3-level ACDF surgery using Zero-P spacers versus those using a traditional plate and cage system. From Sep 2013 to Aug 2016, a total of 44 patients who received 3-level ACDF surgery due to cervical spondylotic myelopathy were recruited. The Zero-P spacer was used in 23 patients (group ZP) and the traditional plate and cage system in 21 (group PC). Clinical outcomes were analyzed by Neck Disability Index (NDI) and Japanese Orthopedic Association (JOA) scores, and dysphagia was evaluated using the Bazaz score. Radiological outcomes, including fusion rate, adjacent segment degeneration (ASD), and especially changes in cervical sagittal alignment, were analyzed. The NDI and JOA scores did not differ significantly between the two groups postoperatively (p &gt; 0.05); however, there was significantly less dysphagia in patients using Zero-P spacers at the 3- and 6-month follow-up (p &lt; 0.05). At the 24-month follow-up, the fusion rate and ASD were similar between the two groups (p &gt; 0.05). Interestingly, patients using Zero-P spacers had a significantly lower postoperative C2-7 Cobb angle and fused segment Cobb angle, compared to those using a traditional plate and cage system (p &lt; 0.05); meanwhile, the fused segment disc wedge was also found to be significantly smaller in patients using Zero-P spacers after surgery (p &lt; 0.05). Moreover, we further divided patients into subgroups according to their cervical lordosis. In patients with a preoperative C2-7 Cobb angle ≤ 10°, significantly less cervical and local lordosis, as well as disc wedge, were seen in group ZP after surgery (p &lt; 0.05), while in others with a preoperative C2-7 Cobb angle &gt; 10°, no significant difference in postoperative changes of the cervical sagittal alignment was seen between group ZP and group PC (p &gt; 0.05). Zero-P spacers used in 3-level ACDF surgery could provide equivalent clinical outcomes and a lower rate of postoperative dysphagia, compared to the traditional plate and cage system. However, our results showed that it was inferior to the cervical plate in terms of sagittal alignment reconstruction for 3-level fixation. We recommend applying Zero-P spacers for 3-level ACDF in patients with good preoperative cervical lordosis (C2-7 Cobb angle &gt; 10°), in order to restore and maintain physiological curvature of the cervical spine postoperatively.

Cervical sagittal alignment is influenced by changes in thoracic and lumbar sagittal alignments after correction surgery in patients with lenke type 6 adolescent idiopathic scoliosis

BackgroundFew studies have examined the changes in cervical sagittal alignment (CSA) and its relationship with other sagittal alignments in AIS patients with major thoracolumbar/lumbar (TL/L) curve who underwent correction surgery. This study investigated the radiographical changes in CSA after correction surgery in patients with Lenke type 6 adolescent idiopathic scoliosis (AIS) and assess any possible factors affecting postoperative CSA. MethodsForty-four patients with Lenke type 6 AIS (3 males and 41 females, mean age at surgery of 15.6 ± 2.8 years) who could be followed up for 3 years after correction surgery were included in this study. Variations of outcome variables were analyzed in various spinal sagittal parameters using radiographic outcomes. Univariate correlation analyses were used to evaluate possible factors influencing the postoperative CSA. The Scoliosis Research Society (SRS)-22 questionnaires and the Oswestry Disability Index (ODI) were used for clinical evaluation, and the changes between pre- and 3-year post-operation were compared. ResultsThe Cobb angle of the major and minor curve was significantly improved after correction surgery. Furthermore, CSA, such as C2-7 angle and T1 slope, changed significantly postoperatively. The magnitude of coronal curve correction did not affect CSA postoperatively, while the postoperative TK, T10-L2 kyphosis and LL were significantly correlated with the postoperative C2-7 angle, respectively. None of the patients in this study complained of neck or low back pain during the period up 3 years after the operation. Comparing each domain of SRS-22 or ODI score, these were unchanged between pre-, 1-year, and 3-year post-operation, with no statistically significant differences. ConclusionsCSA changed significantly after correction surgery, and cervical kyphosis indicated a tendency to decrease in Lenke type 6 AIS patients, which was associated with an improvement in thoracic and lumbar sagittal alignment, not correction for coronal deformity.

Cervical Sagittal Alignment in Patients with Cervical Spondylotic Myelopathy: An Observational Study From the Canadian Spine Outcomes and Research Network.

Prospective cohort study. Among patients with CSM, we aimed to evaluate the extent to which: (1) Preoperative cervical sagittal alignment is associated with health-related quality of life, function, and symptoms; (2) Surgery leads to changes in cervical sagittal alignment; and (3) Postoperative cervical sagittal alignment is associated with health-related quality of life, function, and symptoms at 12 months of follow-up. The importance of maintaining or improving cervical sagittal alignment in the surgical management of patients with CSM has not been established. We measured C2-C7 Cobb angle, T1 slope, and C2-C7 cervical sagittal vertical axis (cSVA). We tested for associations with Neck Disability Index, Pain Scales for neck and arm pain, EuroQol 5D, Short Form 12 Physical and Mental Component Summaries, and modified Japanese Orthopaedic Association scores. We adjusted for potential confounders using multiple linear regression, and we performed various prespecified subgroup (cSVA > 40 mm, surgical approach) and sensitivity analyses. Among 250 patients, adjusted analyses yielded significant inverse associations prior to surgery between each of cSVA and T1 slope with SF12 Physical Component Summaries (T1 slope: -0.14, 95% CI -0.26 to -0.01, P = 0.03; C2-C7 cSVA: -0.13, 95% CI --0.21 to -0.05 P < 0.01). Surgery was associated with a small but statistically significant increase in cSVA across the cohort (+5.8 mm [SD 11.7], P < 0.01) but no change in Cobb angle or T1 slope. At 12-months after surgery, there were no significant associations between alignment parameters or change in alignment and any measures of health-related quality of life, function, or symptoms. Results were consistent across subgroup and sensitivity analyses. Increased cSVA and T1 slope were associated with inferior health-related quality of life at presentation among patients with CSM, but no significant associations were observed following surgical treatment.Level of Evidence: 3.

Does Cervical Alignment Matter? The Effect of 2-level Anterior Cervical Discectomy and Fusion on Sagittal Alignment and Patient-reported Outcomes.

Retrospective review of prospectively collected data. This study aimed to determine the change in cervical sagittal balance following 2-level anterior cervical discectomy and fusion (ACDF) and whether the degree of change was associated with improvement in patient-reported outcomes (PROs). Sagittal balance in cervical spine surgery has been recognized as an important surgical goal. However, its influence on clinical outcomes following anterior decompressive procedures remains debatable. Patients who underwent primary 2-level ACDF for cervical spondylotic radiculopathy and/or myelopathy were identified from an institutional spine registry. Radiographic measurements were done preoperatively, postoperatively, and at minimum 24 months follow-up. Measurements comprised segmental lordosis (SL), C2-C7 cervical lordosis (CL), C2-C7 sagittal vertical axis, C7 slope (C7S), T1 slope (T1S) and C7 slope minus cervical lordosis (C7S-CL). Disk heights were measured preoperatively and postoperatively. PROs including the Neck Disability Index, Short Form-36, and Visual Analog Scale for neck pain and arm pain were collected preoperatively and at 24 months postoperatively. In total, 90 patients were included. Mean follow-up was 58.6±22.9 months. Significant improvement in all PROs was achieved at 24 months (P<0.05). SL was -1.2±8.2 degrees preoperatively, increased to 5.2±5.9 degrees postoperatively (P<0.001), and decreased to 1.2±6.2 degrees at follow-up (P=0.005). CL was 8.5±12.5 degrees preoperatively, increased to 10.8±12.4 degrees postoperatively (P=0.018), and maintained at 10.9±11.2 degrees at follow-up (P=0.030). Sagittal vertical axis, C7S, T1S, and C7S-CL did not change significantly. Significant increases in disk heights were achieved postoperatively (P<0.001). Fusion rate was 98.9% at follow-up. PROs were not related to radiologic measurements. Maintaining or increasing CL or SL was not related to a greater degree of improvement in PROs. Two-level ACDF restored segmental and global CL, but changes in cervical sagittal alignment did not correlate with the magnitude of improvement in PROs. Adequate decompression with solid fusion remains fundamental to achieving good clinical outcomes in patients with degenerative cervical disease.

Radiological changes in sagittal parameters after C1-C2 arthrodesis and their clinical correlation: is there a difference between traumatic and non-traumatic causes?

Background Compensatory changes in cervical sagittal alignment after C1-C2 arthrodesis have been reported in a few studies. No studies have explored the differences in these compensatory changes between traumatic and non-traumatic pathologies. Conflicting reports exist on the correlation between cervical sagittal parameters and neck pain or function. Methodology Medical records of 81 consecutive patients [Jan 2010–Dec 2018] who underwent Harms arthrodesis were retrospectively reviewed. 53 patients were included in the final analysis. Radiological parameters [C0-C1, C1-C2, C2-C7 angles and T1 slope] and clinical parameters [VAS (Visual analogue scale) and NDI (Neck disability index)] were compared between the two groups, Group A (traumatic) and Group B (non-traumatic). Results The 53 patients [Group A (n = 24,) and Group B (n = 29)] had a mean age of 49.98 ± 21.82 years (42 males, 11 females). Mean follow up duration was 48.9 months. Δ C1-C2 angle is significantly correlated with ΔC2-C7 angle (Group A, p = 0.004; Group B, p = 0.015) but not with ΔC0-C1 angle (Group A, p = 0.315; Group B, p = 0.938). Though significant improvement in the clinical parameters (VAS/NDI) has been noted in both groups, Group A showed a greater improvement in VAS scores [Group A, (p < 0.001); Group B, (p < 0.023)]. Conclusions The sub-axial sagittal profile was strongly correlated with the ΔC1-C2 angle in both groups. Group B showed greater changes in sagittal parameters after Harms fixation and Group A showed greater improvement in long-term functional outcomes. The final functional outcomes were not related to the initial or final radiological sagittal profile in both groups.

The Relationship Between Cervical Sagittal Balance and Adjacent Segment Disease After Three-level Anterior Cervical Discectomy and Fusion.

Retrospective review of prospectively collected data. To determine the relationship between cervical sagittal balance and adjacent segment degeneration (ASD) development after 3-level anterior cervical discectomy and fusion (ACDF). ASD is a common complication after ACDF. Previous studies have shown that sagittal imbalance may be associated with ASD development after 1-level or 2-level ACDF. However, these findings may not be generalizable to 3-level procedures. We reviewed prospectively collected data of 46 patients who underwent 3-level ACDF at a tertiary institution. Lateral cervical radiographs taken preoperatively, postoperatively, and at last follow-up were reviewed for ASD. The mean follow-up duration was 5 years. Radiographic parameters measured were cervical sagittal alignment (CSA), segmental sagittal alignment, T1 slope (T1S), sagittal vertical axis, and T1S-cervical lordosis. ASD was present in 27 (58.7%) patients, but only 1 patient (2.2%) underwent reoperation at 4.8 years. The CSA, sagittal vertical axis, and T1S were similar preoperatively, but the T1S-cervical lordosis was higher in the ASD group (18.28 vs. 9.82, P =0.016). All 4 parameters were similar postoperatively and at last follow-up. The ASD group had a greater change in CSA over the follow-up period (-6.26 vs. -1.47, P =0.05), but they achieved similar sagittal alignment at last follow-up. There was no difference in clinical outcomes between the 2 groups. Unlike studies on 1-level and 2-level ACDF, this study found that cervical spinal alignment was not associated with ASD development after 3-level ACDF. ASD development also had no impact on clinical outcomes at 2 years. Level III-nonrandomized cohort study.

Does Selective Posterior Correction and Fusion Surgery Influence Cervical Sagittal Alignment in Patient with Lenke Type 5 Adolescent Idiopathic Scoliosis?-A 5-year Follow-up Retrospective Cohort Study.

A retrospective comparative study. The aim of this study was to examine the changes in cervical sagittal alignment (CSA) following surgical correction in a patient with Lenke type 5 adolescent idiopathic scoliosis (AIS) and evaluate any possible factors influencing postoperative CSA. Few studies have assessed the association between CSA and thoracic or lumbar sagittal alignment in AIS patients with major thoracolumbar/lumbar curve who underwent posterior correction and fusion surgery. Sixty-six patients with Lenke type 5 AIS (two males and 64 females, the mean age at surgery of 16.2 years) were included in this study. They were followed up for minimum 5 years after surgery. Multiple linear regression analysis was used to evaluate possible factors influencing the postoperative CSA. To determine the influence of upper end vertebra (UEV) level on postoperative CSA, the subjects were divided into two groups according to UEV level of ≥T9 or ≤T10. The outcome variables were compared between the two groups and analyzed for changes in various spinal sagittal profiles using radiographic outcomes. Multiple linear regression analysis revealed that preoperative T10-L2 kyphosis and LL were significantly correlated with postoperative C2-7 lordosis. However, CSA did not significantly change at 5 years after surgery. Sub-analysis of the cohort revealed that in the UEV ≥T9 group, the mean thoracic kyphosis significantly increased from 20.3° ± 10.6° to 24.0° ± 8.9° and the mean C2-7 lordosis also significantly increased from -12.5° ± 8.3° to -4.3° ± 10.3° at 5-year postoperatively. SRS-22 outcomes were comparable between the groups. We indicated that the CSA was not influenced by surgical correction in most Lenke type 5 AIS patients. However, in a patient whose UEV was located at T9 or higher levels, CSA was influenced through the changes in thoracic kyphosis following posterior correction surgery.Level of Evidence: 4.

Changes in cervical sagittal alignment and the effects on cervical parameters in patients with cervical spondylotic myelopathy after laminoplasty.

Objective:To monitor changes in cervical parameters before and after laminoplasty surgery. Cervical parameters and health-related quality-of-life (HRQOL) values that may be affected after laminoplasty were examined before and after surgery. The clinical and radiological course of these values was monitored, and their interaction with all spinal radiological parameters was revealed.Materials and Methods:Nineteen patients who underwent clinical and radiological evaluation for 2 years were followed in this study. Neck disability index, visual analog scale, and short form 36 scores were determined to evaluate HRQOL. For radiological parameters, the C0-C2 angle, C2-C7 angle, cervical sagittal vertical axis, T1 slope angle, neck tilt (NT) and thoracic inlet angle were used. The results of the 4-month, 1 year and 2-year follow-ups were statistically evaluated.Results:Both the HRQOL and cervical radiological parameters deteriorated in the first 4 months and returned to normal in the 2nd year. Statistically, all parameters were meaningful (P < 0.05), except for NT.Conclusion:Cervical parameters and HRQOL values, which deteriorated in the early period, recovered in the late period in the long-term follow-up of patients undergoing laminoplasty. The important point is that preoperative cervical parameters suitable for laminoplasty should be present, and spinopelvic parameters should be normal.

Age-related Changes in Cervical Sagittal Alignment

Retrospective cohort study. To identify age-related changes in cervical sagittal parameters using standard radiographs. Cervical sagittal balance is important for the maintenance of neutral head posture and horizontal gaze. Degenerative changes in the cervical spine that occur with aging may alter cervical sagittal balance, which can lead to chronic neck pain and predispose to various cervical spine pathologies. We performed a retrospective cohort study of 151 patients with lateral cervical spine radiographs taken at our institution between December 2017 and June 2018. Cervical sagittal parameters were measured, including C1 inclination, C2 slope, C2-C7 Cobb angle, cervical sagittal vertical axis (cSVA), cervical tilt, upper and lower C7 slopes, T1 slope, and T1 slope minus cervical lordosis (TS-CL). The association between age and cervical sagittal parameters was assessed using the Pearson correlation coefficient and a linear regression analysis. An analysis of variance (ANOVA) with Tukey adjustments was then performed to identify differences in cervical sagittal parameters among patients aged 18 to 39 years, 40 to 64 years, and >64 years of age. There were positive correlations between age and C2-C7 Cobb angle (r = 0.231, P = 0.004), upper C7 slope (r = 0.280, P < 0.001), lower C7 slope (r = 0.283, P < 0.001), and T1 slope (r = 0.189, P = 0.020). Upper C7 slope (R = 0.079) and lower C7 slope (R = 0.074) had the strongest correlation with age in the linear regression analysis. The ANOVA found significant differences among the age subgroups in terms of C2-C7 Cobb angle (P = 0.002), upper C7 slope (P < 0.001), lower C7 slope (P < 0.001), and T1 slope (P = 0.031). Patients >64 years old had significantly higher C2-C7 Cobb angle, upper C7 slope, lower C7 slope, and T1 slope. Changes in cervical sagittal alignment with age are characterized by increased cervical lordosis and increased thoracic kyphosis. 3.

Cervical sagittal alignment and the impact of posterior spinal instrumented fusion in patients with Lenke type 1 adolescent idiopathic scoliosis

Clinical decision making, preoperative planning, and surgical correction for adolescent idiopathic scoliosis (AIS) has traditionally focused on obtaining the maximum coronal plane correction to improve cosmesis and function. More recently, restoring sagittal alignment has also received increasing attention in AIS patients, correlating with positive health-related quality of life (HRQOL) outcomes in multiple studies. In this realm, cervical sagittal alignment (CSA) has also emerged as one of the variables that may correlate with clinical and functional outcomes in AIS patients undergoing surgical correction. Several studies have focused on studying the cervical sagittal plane parameters in patients with spinal deformity, while few have investigated the impact of surgical correction on CSA. In this study, we aimed to capture the baseline cervical sagittal characteristics and evaluate the changes in CSA in a cohort of AIS patients with Lenke type I curves following posterior spinal instrumented fusion (PSIF). We evaluated our longitudinal database of patients who had surgical correction for AIS between January 1, 2015 and September 1, 2017. The initial search yielded 270 patients. Next, the following inclusion criteria were applied to identify the study cohort: (I) patients who had Lenke type 1 curves, (II) patients with adequate pre-operative and post-operative radiographs (posterior-anterior and lateral), (III) patients who had a minimum radiographic follow-up of 6 months, and (IV) patients who were treated with the same standard rod instrumentation system. In addition, the following exclusion criteria were applied: (I) patients with neuromuscular disorders, (II) patients with prior spine surgery, and (III) those who received greater than Schwab-2 osteotomies. A total of 30 patients were included in our final analysis. The C2-C7 angle, C0-C2 angle, C2-C7 sagittal vertical axis (SVA), McGregor slope (McGS), and the T1 slope angle were measured preoperatively and at 6 months. A kyphotic measurement was assigned a negative value while positive values were used to describe lordotic measurements. Descriptive statistics and paired sample t-test were used to compare pre-and post-operative data with a cutoff P value of 0.05 to determine statistical significance. Overall, CSA improved in most patients post-operatively, with 19/30 (63%) resulting in improved lordosis. Pre-operatively, mean C2-C7 cervical lordosis was -4.3°, which improved to -0.5° postoperatively (P=0.075), with a mean difference of 3.7°. Simultaneously, mean C0-C2, C2-C7 SVA, McGS, and T1 slope changed from 17° (range, -18° to 41°), 26.5 mm (range, 10 to 45 mm), 4° (range, -7.5° to 25°), and 17.4° (range, 1° to 42°) to 16° (range, 0° to 34.4°, mean difference =1.01°, and P=0.548), 28.2 mm (range, 9 to 57 mm, mean difference =2 mm, and P=0.244), 4.03°, (range, -7.8° to 25°, mean difference =0.16, and P=0.916), and 18° (range, 5.4° to 42°, mean difference =0.37, and P=0.761) (mean change of C2-C7 angle of 3.76°). This study demonstrated baseline cervical kyphosis and a trend towards cervical lordosis restoration in patients with AIS and a Lenke type 1 curve who underwent PSIF. This study adds to emerging evidence and, together with further studies, will help estimate the impact of PSIF on the cervical sagittal profile, the effect of CSA on patient reported outcomes, and ways to address cervical sagittal malalignment when undertaking the surgical correction for specific curve types in AIS.

The change of cervical sagittal alignment after surgery for adolescent idiopathic scoliosis

ObjectiveThe postoperative change in cervical sagittal alignment has an impact on health-related quality of life in adolescent idiopathic scoliosis (AIS) patients who have undergone deformity correction. However, the effect of deformity correction on sagittal cervical profile is still controversial in the literatures. The objective of this study was to investigate the postoperative change in the cervical sagittal alignment of patients with AIS. Patients and methodsA total of 46 AIS patients treated by posterior instrumentation and fusion with pedicle screw constructs were included in the study. Radiographs were collected preoperatively, immediate postoperatively and at the final follow-up. The C2-C7 Cobb angle and C2-C7 sagittal vertical axis (cSVA) were used to assess the cervical sagittal alignment. Spinopelvic alignment parameters, such as thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), and sagittal vertical axis (SVA), were also measured. The correlations between the cervical sagittal parameters and spinopelvic parameters were analyzed. ResultsThe incidence of cervical kyphosis was 67.4% preoperatively but increased to 87% postoperatively and 69.5% at the final follow-up. The C2-C7 Cobb angle significantly increased from pre-operation (−1.5° ± 15°) to post-operation (−5.4° ± 7.3°; P < 0.05) and spontaneously decreased to −2.9° ± 10.5° at the final follow up. The cSVA was 18.1 ± 13 mm preoperatively, 17 ± 12.3 mm after surgery and 18.5 ± 9.5 mm at the last follow-up, but the change was not statistically significant (P > 0.05). TK decreased significantly from pre-operation (17.7° ± 14.4°) to post-operation (14.2° ± 7.6°) and spontaneously improved to 16.9° ± 8.2° at the final follow-up. TK showed a significant correlation with the C2-C7 Cobb angle, but not with cSVA, in the preoperative (r = 0.709, P < 0.01), postoperative (r = 0.472, P < 0.01), and last follow-up measurements(r = 0.505, P < 0.01). Compared with patients with preoperative thoracic hypokyphosis or hyperkyphosis, patients with a normal thoracic spine had more significant postoperative changes in the C2-C7 Cobb angle and TK. ConclusionsCervical sagittal alignment after deformity correction is altered in AIS patients. An increase in cervical kyphosis after surgery is correlated with a loss of thoracic kyphosis. The change in the cervical sagittal profile may be a compensatory mechanism in response to an abnormal thoracic sagittal profile.