Comparison of Cervical Sagittal Parameters Between Radiographs and Magnetic Resonance Images in Patients With Cervical Spondylotic Myelopathy

Study Design Observational study Objective As an important consideration of surgery, cervical sagittal balance is believed to be better assessed using standing radiograph than supine magnetic resonance imaging (MRI). However, few studies have researched this. Our study aimed to observe the correlations and differences in cervical sagittal parameters between radiograph and MRI in patients with cervical spondylotic myelopathy (CSM), and evaluate whether the change of position affects them. Methods We analyzed 84 patients, measuring Cobb angle (CA), T1 slope (T1S), neck tilt (NT), and thoracic inlet angle (TIA). Inter- and intra-parameter analyses were performed to identify any difference between standing radiograph and supine MRI. Statistical correlations and differences between the parameters were compared. Results There were excellent inter-observer agreement for each parameter (interclass correlation coefficient >.75), and significant differences were observed in each parameter between radiograph and magnetic resonance imaging ( P < .05). Strong correlations were noted between the same parameters in radiograph and MRI. Cobb angle, T1S, and neck tilt were significantly correlated with thoracic inlet angle on both radiograph and MRI, and CA was significantly correlated with T1S on both radiograph and MRI ( r: −1.0 to −.5 or .5 to 1.0). Conclusion Supine MRI obviously underestimated the value of CA, T1S, and TIA. Therefore, standing cervical radiographs should be obtained in CSM patients to assess and determine surgical strategy, not only supine MRI. Moreover, we observed that NT and TIA were not constant morphological parameters.

The effects of vertebral body tethering on sagittal parameters: evaluations from a 2-years follow-up

Introduction While the effects of VBT on coronal parameters have been investigated in various studies, this has not yet been the case for sagittal parameters. This is of particular relevance considering that VBT does not allow direct correction of the sagittal profile. Thus, we investigated the effects of VBT on sagittal parameters in patients with adolescent idiopathic scoliosis. Materials and methods Retrospective, 2-Center study. Patients who underwent VBT and presented a 2-years follow-up were included. The differences in sagittal parameters were evaluated, along with modifications of sagittal profile following Abelin-Genevois’ classification. Results Data from 86 patients were obtained. Mean Cobb angle was 52.4 ± 13.9° at thoracic level and 47.6 ± 14.3° at lumbar level before surgery, and 28.5 ± 13.6 and 26.6 ± 12.7° at the 2-year follow-up, respectively. Mean thoracic kyphosis increased from 28.3 ± 13.8 to 33 ± 13°, the lumbar lordosis (LL) was unvaried (from 47.5 ± 13.1 to 48.4 ± 13.5°), PT decreased from 9.4 ± 8.5 to 7.4 ± 6.1°, the sagittal vertical axis SVA decreased from 4.5 ± 31.4 to − 3.6 ± 27.9 mm. No kyphotic effect on LL in patients who underwent lumbar instrumentation was observed. Before surgery, 39 patients had a type 1 sagittal profile, 18 were type 2a, 14 type 2b and 15 type 3. Postoperatively, 54 were type 1, 8 were 2a, 13 were 2b and 11 were type 3. Conclusions VBT positively influences sagittal parameters and does not have a kyphotic effect on LL.

Variation in Sagittal Alignment Parameters in Adult Patients before Spine Surgery: A Serial Imaging Study Using Antero-Posterior and Latero-Lateral Projections

Sagittal parameters of the spine are closely related to the evaluation and treatment of spine disease. However, there has been little research on variations in preoperative sagittal spinal alignment. This study was conducted to assess the variation in sagittal spinal alignment on serial antero-posterior and latero-lateral projections (EOS imaging) in adult patients before spine surgery. The sagittal parameters of 66 patients were collected from two serial images. Comparison between the first and second sagittal parameters was evaluated using the Wilcoxon signed-rank test. Subgroup analysis was performed based on the time interval between radiographs, patient’s age, and type of surgery. The sagittal vertical axis (SVA) exhibited statistically significant changes (p = 0.023), with the mean SVA increasing statistically (61.7 mm vs. 73.6 mm) and standard deviation increasing (51.5 mm vs. 61.6 mm) in the second image. Subgroup analysis showed significant differences in SVA (p = 0.034) in patients with an interval of >3 months; statistical differences in borderline levels in the SVA (p = 0.049) were observed in patients aged >65 years. Other parameters did not show statistically significant differences, except for SVA. Furthermore, SVA differences were statistically significant with increases in the EOS interval (>3 months) and patient age (>65 years).

Assessment of sagittal spinopelvic alignment in asymptomatic Chinese juveniles and adolescents: a large cohort study and comparative meta-analysis

Study design Retrospective study and comparative meta-analysis. Objective To document the sagittal spinopelvic alignment in a large cohort study in asymptomatic Chinese juveniles and adolescents, and to explore whether these parameters were different from various regions using meta-analysis. Methods Medical records of 656 asymptomatic Chinese juveniles and adolescents were reviewed, whose mean age was 13.14 ± 3.41 years old, including 254 male and 402 female volunteers. Demographic and lateral radiological parameters were evaluated. Furthermore, a systematic online search was performed to identify eligible studies. Weight mean difference (WMD) with 95% confidence interval (CI) were used to evaluate whether these sagittal parameters were different from various regions. Results The mean value of sagittal spinopelvic alignment in this study was calculated and analyzed respectively. Significant differences of PI (34.20 ± 4.00 vs. 43.18 ± 7.12, P < 0.001) and PT (3.99 ± 6.04 vs. 8.42 ± 7.08, P < 0.001) were found between juveniles and adolescents. A total of 17 studies were recruited for meta-analysis. For juvenile populations, TK, PI and SS of Caucasians were significantly larger than those of our study (all P < 0.001). As for adolescent populations, PI (P = 0.017), TK (P = 0.017) and SS (P < 0.001) of Caucasians was found to be greater when compared with that of our study. All in all, TK, PI and SS in Chinese pre-adult populations were significantly smaller than those populations in Caucasian regions (all P < 0.001). Conclusion Our study was the first large-scale study that reported the mean values of sagittal parameters in asymptomatic Chinese juveniles and adolescents. There were significant differences in TK, PI and SS between our study and other previous reported populations, which reminded us for using specific mean values in different populations when restoring a relatively normal sagittal spinopelvic balance in spinal deformity.

Efficacy and Sagittal Parameters of Debridement and Bone Grafting using Internal Fixation in the Treatment of Kyphotic Cervical Tuberculosis: A Case Series

Background: To evaluate the efficacy of debridement and bone grafting using internal fixation in the treatment of kyphotic cervical tuberculosis, and analyze the changes of pre-operation and post-operation sagittal parameters, which related to the surgical indications.Methods: Clinical and radiographic data of patients with kyphotic cervical TB treated by debridement and BGIF at our hospital from January 2010 to December 2017 were analyzed retrospectively. The sagittal parameters of the cervical vertebra at the pre-operation, post-operation, and last follow-up were documented and were compared. Results: Eighteen patients of simple anterior approach debridement and fusion with internal fixation (group A), and 5 patients underwent anterior debridement and fusion, combined with posterior internal fixation (group AP). In the comparison of preoperative sagittal parameters, significant improvement after surgery was observed in both groups, included Cobb angle, SCA, C2-C7SVA, and CG-SVA (P < 0.05). There were no significant differences in T1 Slope, NT, and TIA (P > 0.05).Conclusions: In the treatment of kyphotic cervical TB, the characteristics of the lesion, the degree of kyphosis and spinal cord nerve compression damage can be presented clearly by the radiographic sagittal parameters, which does a favor to individualize the choice of surgical approach safely and effectively.

Endplate Abnormalities in Cervical Spondylotic Myelopathy and Association with Pre- and Post-operative(Single-level ACDF with a Zero-P Implant)Sagittal Parameters and Clinical Outcomes.

Background:Endplate abnormalities in cervical spine were closed related to pre- and post-operative symptoms, and might lead to a certain complication. However, the related researches are few, and the associations between endplate abnormalities and clinical outcomes need more evidence. Correlations between endplate abnormalities and pre- and post-operative cervical sagittal parameters also remain unknown. The purpose of this study was to explore endplate abnormalities in cervical spondylotic myelopathy, and to find potential associations of endplate abnormalities with preoperative cervical sagittal parameters, disc degeneration and symptoms, and clinical outcomes after ACDF.Method:We enrolled 65 patients (34 males, 31 females) who were diagnosed with CSM and were subjected to single-level ACDF with a Zero-P implant at our hospital from 2015 to 2018. The patients were divided into two groups according to whether the endplate was abnormal.We conducted a retrospective study to compare the clinical and radiological results among the two groups.Results:The average age in endplate abnormality group was higher than it in no abnormality group (P<0.001). T1S was significantly higher in abnormality group than in the normal group of preoperative (P<0.05) and kept significantly different from postoperative and 1 year follow up (P<0.05). No significantly different was found between the two groups as for CA, cSVA, intervertebral height and preventable soft-tissue thickness. The incidence rate of interbody cage subsidence was 25.9% in 2 years follow up, which was significantly higher than that in the normal group (P<0.05). The fusion rate in endplate abnormality group was 89%. No significantly difference was found between the two groups. The Miyazaki grade of the disc in endplate abnormality group was significantly higher than it in the normal group (P<0.01).Significant difference was detected on NDI between the two groups.Conclusions: Endplate abnormalities in cervical spondylotic myelopathy were associated with older age, disc degeneration, decrease of intervertebral height and increase of TS before cervical surgery. Patients in endplate abnormality group showed increase in NDI pre- and post-operation, and more phenomenon of subsidence.