The ratio of C2-C7 Cobb angle to T1 slope is an effective parameter for the selection of posterior surgical approach for patients with multisegmental cervical spondylotic myelopathy.

BACKGROUND: To our knowledge, laminectomy with fusion (LCF) and laminoplasty alone (LP) are both effective posterior surgical approaches for decompression of cervical spondylotic myelopathy (CSM). However, which one is suitable for patients has no standard answer. This study estimated whether the ratio of C2-C7 Cobb angle to T1 slope (CL/T1S) could be an indication of posterior surgical approach. METHODS: We retrospectively reviewed 128 patients with at least 6 months of follow-up who underwent LCF or LP. Radiological measurements, including C2-C7 Cobb angle, decompressed Cobb angle, T1 slope, cervical sagittal vertical axis, and curvature index (CI), and clinical outcomes, including Japanese Orthopedic Association score and visual analogue scale were evaluated. ROC curve analysis was used to identify discriminative power of CL/T1S ratio to predict kyphotic deformity and severe lordosis loss. The t-test and Mann-Whitney U-test were used to evaluate the difference between LCF and LP. Kruskal-Wallis H - test and ANOVA were used to evaluate the difference among different ratio CL/T1S groups. RESULTS: The cervical lordosis decreased after LCF or LP (p < 0.001, p < 0.001, respectively). Based on ROC curve analysis, CL/T1S ratio had a good discriminative power to predict kyphotic deformity and severe lordosis loss (AUC = 0.70, AUC = 0.88, respectively). According to CI value changes, cervical lordosis losses in group LP were larger than that in group LCF (p = 0.006). However, there was no significant difference in CI changes of fair-ratio CL/T1S group between LCF and LP. For patients with low CL/T1S ratio or high CL/T1S ratio, CI changes in group LP were greater than that in group LCF (p = 0.037, p = 0.042, respectively). CONCLUSIONS: CL/T1S ratio could be an indication of posterior surgical approach. Compared with LP, LCF reduces postoperative cervical lordosis losses in low-ratio and high-ratio CL/T1S groups.

Correlation between multifidus muscle atrophy, spinopelvic parameters, and severity of deformity in patients with adult degenerative scoliosis: the parallelogram effect of LMA on the diagonal through the apical vertebra.

BACKGROUND: There were several reports describing the biomechanics and microstructure of multifidus muscles in patients with lumbar disc herniation. However, correlations between lumbar multifidus muscle atrophy (LMA), spinopelvic parameters, and severity of adult degenerative scoliosis (ADS) have not been investigated. The study evaluated the impact of LMA and spinopelvic parameters on the severity of ADS. METHODS: One hundred and thirty-two patients with ADS were retrospectively reviewed. Standing whole-spine X-ray was used to evaluate the coronal (coronal Cobb angle, CA; coronal vertical axis, CVA) and sagittal (sagittal vertical axis, SVA; thoracic kyphosis, TK; lumbar lordosis, LL; pelvic incidence, PI; pelvic tilt, PT; sacral slope, SS) parameters. LMA was evaluated on axial T2-weighted magnetic resonance imaging (MRI) at intervertebral levels above and below the vertebra at the apex of the scoliotic curve. Clinical symptoms were evaluated by the Oswestry Disability Index (ODI) and the Japanese Orthopaedic Association (JOA) score. Multiple linear regression was used to assess correlations between LMA, spinopelvic parameters, and severity of scoliosis. RESULTS: LL and PT were negatively correlated with CA (P < 0.001); LL was positively correlated with SVA (P < 0.001). PI was positively correlated with CA (P < 0.001) and CVA (P < 0.001). PT (P < 0.001) and SS (P < 0.001) were negatively correlated with CVA. SS was negatively correlated with SVA (P < 0.001). Concave LMA at the upper or lower intervertebral level of the apical vertebra was positively correlated with CA (P ≤ 0.001); convex LMA at the upper or lower intervertebral level was negatively correlated with CA (P < 0.001). Convex LMA at the upper intervertebral level and concave LMA at the lower intervertebral level of the apical vertebra were negatively correlated with the SVA (P ≤ 0.001). At the upper intervertebral level, LMA on the concave side was positively correlated with CVA (P = 0.028); LMA on the convex side was negatively correlated with CVA (P = 0.012). PI was positively correlated with ODI (P < 0.001); PT (P < 0.001) and SS (P < 0.001) were negatively correlated with ODI. At the lower intervertebral level, LMA on the concave side was positively correlated with ODI (P = 0.038); LMA on the convex side was negatively correlated with ODI (P = 0.011). PI was positively correlated with JOA (P < 0.001); PT (P < 0.001) and SS (P < 0.001) were negatively correlated with JOA. CONCLUSIONS: Spinopelvic parameters are correlated with the severity of ADS. Asymmetric LMA at both upper and lower intervertebral levels of the apical vertebra is positively correlated with CA. LMA on the diagonal through the apical vertebra is very important to maintain sagittal imbalance via parallelogram effect. LMA at lower intervertebral levels of the apical vertebra may have a predictive effect on ODI. JOA score seems to be more correlated with spinopelvic parameters than LMA.

Factors associated with postoperative outcomes in patients with intramedullary Grade II ependymomas: A Systematic review and meta-analysis.

BACKGROUND: Most of the previous studies combined all types of intramedullary ependymomas without providing accurate pathological subtypes. In addition, it was very difficult to evaluate the factors associated with postoperative outcomes of patients with different pathological subtypes of intramedullary Grade II ependymomas by traditional meta-analysis. This study evaluated the factors related with postoperative outcomes of patients with intramedullary Grade II ependymomas. METHODS: Individual patient data analysis was performed using PubMed, Embase, and the Cochrane Central Register of Controlled Trials. The search included articles published up to April 2018 with no lower date limit on the search results. The topics were intramedullary Grade II ependymomas. Progression-free survival (PFS) and overall survival (OS) were analyzed by Kaplan-Meier survival analysis (log-rank test). The level of significance was set at P < .05. RESULTS: A total of 21 studies with 70 patients were included in this article. PFS of patients who underwent total resection was much longer than the PFS of those who received subtotal resection (P < .001). Patients who received adjuvant therapy (P = .005) or radiotherapy and chemotherapy (P < .001) seemed to have shorter PFS than others; PFS of patients who had cerebrospinal fluid disease dissemination (P = .022) or scoliosis (P = .001) were significantly shorter than others. OS of cellular ependymoma patients was less than giant cell ependymoma patients (P < .001). CONCLUSIONS: PFS of patients who received total resection was much longer than those who received subtotal resection. Patients treated with adjuvant therapy or radiotherapy and chemotherapy appeared to have shorter PFS than others; PFS of patients with cerebrospinal fluid disease dissemination or scoliosis were significantly shorter than others. Cellular ependymomas would have better OS than giant cell ependymoma. However, giant cell ependymoma patients might have the worst OS.

The Parallelogram Effect of Degenerative Structures Around the Apical Vertebra in Patients with Adult Degenerative Scoliosis: The Influence of Asymmetric Degeneration and Diagonal Degeneration on the Severity of Deformity.

BACKGROUND This is the first published study assessing the parallelogram effect of degenerative structures around the apical vertebra. We evaluated the effect of degenerative structures around the apical vertebra and spinopelvic parameters on the severity of ADS. MATERIAL AND METHODS We retrospectively reviewed data on 144 patients with ADS. The coronal (coronal Cobb angle, CA) and sagittal (thoracic kyphosis, TK; sagittal vertical axis, SVA; pelvic incidence, PI; lumbar lordosis, LL; sacral slope, SS; pelvic tilt, PT) parameters, lumbar multifidus muscle atrophy (LMA), and facet joint osteoarthritis (FJOA) were evaluated. Multiple linear regression was used to assess the correlations. RESULTS LL and PT were negatively correlated with CA (P<0.001), and the correlation between LL and SVA was positive (P<0.001), as was the correlation between PI and CA (P<0.001). The correlation between SS and SVA was negative (P<0.001). The correlation between CA and concave LMA at upper or lower intervertebral level of the apical vertebra was positive (P≤0.001). The convex LMA at upper and lower intervertebral levels was negatively correlated with CA (P<0.001). Convex LMA at the upper intervertebral level and concave LMA at the lower intervertebral level of the apical vertebra were negatively correlated with the SVA (P≤0.001). FJOA works similar to LMA (P<0.05). CONCLUSIONS Spinopelvic parameters are correlated with severity of ADS. The structures around the apical vertebra are very important to maintain global alignment of the spine via the parallelogram effect.

Influence of the Ratio of C2-C7 Cobb Angle to T1 Slope on Cervical Alignment After Laminoplasty.

PURPOSE: To assess the relationship between the ratio of C2-C7 Cobb angle to T1 slope (CL/T1S) and cervical alignment changes after laminoplasty. METHODS: 78 consecutive patients with cervical myelopathy who underwent laminoplasty were enrolled. All patients with preoperative and follow-up cervical spine lateral x-ray images available for review were recruited in this study. Imaging data included C2-C7 Cobb angle, T1 slope, and cervical sagittal vertical axis (cSVA). All patients were classified into low-ratio group (bottom 25% of CL/T1S), fair-ratio group (middle 50% of CL/T1S), and high ratio group (top 25% of CL/T1S) according to CL/T1S ratio. The recovery rate was calculated based on the Japanese Orthopedic Association score. RESULTS: The preoperative C2-C7 Cobb angle had significant correlations with the T1 slope (r = 0.528). Kyphotic alignment changes in the group with a high ratio of CL/T1S was greater than that of the other 2 groups (P < 0.001). The incidence of postoperative kyphosis in the group with a low ratio of CL/T1S was higher than that of the other 2 groups (P < 0.001). There was no postoperative kyphosis in the fair-ratio group. The surgical outcome in the low-ratio CL/T1S group and the high-ratio CL/T1S group was poorer than that in the fair-ratio CL/T1S group (P = 0.005). CONCLUSIONS: The cervical alignment was kept well in the mid-range CL/T1S ratio group after laminoplasty. Patients with a high CL/T1S ratio were more likely to present with kyphotic alignment changes. Patients with a low CL/T1S ratio were more likely to have postoperative kyphosis.

Clinical and magnetic resonance imaging predictors of the surgical outcomes of patients with cervical spondylotic myelopathy.

OBJECTIVE: To determine whether clinical characteristics and signal and morphologic changes on magnetic resonance (MR) images of the spinal cord (SC) are associated with surgical outcomes for cervical spondylotic myelopathy (CSM). PATIENTS AND METHODS: A total of 113 consecutive patients with cervical myelopathy underwent cervical decompression surgery in our hospital from January 2015 to January 2018. All patients with preoperative MR images available for review were recruited for this study. Research data included patient sex, age, duration of symptoms, surgical approach, compression level, preoperative mJOA (modified Japanese Orthopaedic Association) score, postoperative mJOA recovery rate, and complications. Imaging data included signal changes on T2-weighted MRI images (grade and extension on sagittal images, four types of signal changes on axial images according to the Ax-CCM system), SC compression, transverse area of the SC, and compression ratio. The t-test, Mann-Whitney U-test, Kruskal-Wallis H - test, analysis of variance, and regression analysis were used to evaluate the effects of individual predictors on surgical outcomes. RESULTS: The study cohort included 85 males and 27 females with a mean age of 60.92 ± 8.93 years. The mean mJOA score improved from 10.24 ± 1.69 preoperatively to 15.11 ± 2.05 at the final follow-up (p < 0.001). Patients in the poor outcome group were more likely to present with a longer duration of symptoms (p < 0.001) and smaller transverse area of the SC (p < 0.001). Bright T2-weighted high signal changes (T2HSCs), multisegmental high signal changes on sagittal MR images, and fuzzy focal T2HSCs on axial MR images were associated with a poor outcome (p < 0.001, p = 0.005, p < 0.001, respectively). The maximum SC compression and compression ratio were not reliable predictors of surgical outcomes (p = 0.375, p = 0.055, respectively). The result of multivariate stepwise logistic regression showed that a longer duration of symptoms, multisegmental T2HSCs on sagittal MR images and fuzzy focal T2HSCs on axial MR images were significant risk factors of poor outcomes (p < 0.001, p = 0.049, p = 0.016, respectively). CONCLUSION: A longer duration of symptom, multisegmental T2HSCs on sagittal MR images, and fuzzy focal T2HSCs on axial MR images were highly predictive of a poor surgical outcome for CSM. Smaller transverse area of the SC and bright T2HSCs were also associated with the prognosis of CSM.

Survival outcomes and prognostic factors of patients with intramedullary Grade II ependymomas after surgical treatments.

This study evaluated survival outcomes of patients with intramedullary Grade II ependymomas and identify prognostic factors. Electronic searches of PubMed, EMBASE, OVID, the Cochrane Central Register of Controlled Trials were performed to identify trials according to the Cochrane Collaboration guidelines. The objects were intramedullary Grade II ependymoma according to 2007 WHO classification. Kaplan-Meier survival analysis with log-rank test was used to analyze progressive free survival (PFS) and overall survival (OS). Cox proportional hazard model was utilized for multivariate analysis with hazard ratio (HR) and 95% confidence interval (CI) calculated. P values <0.05 were considered statistically significant. A total of 28 studies including 138 cases of intramedullary Grade II ependymomas were retrieved. Patients who were classified as cellular ependymomas or papillary ependymomas had higher risks of progression than those who possessed typical Grade II ependymomas. Patients who were treated with adjuvant therapy had a higher risk of progression than those without adjuvant therapy. OS of patients with giant cell ependymoma was significantly shorter than those with typical Grade II ependymoma. Patients who had cellular or papillary subtype, adjuvant therapy would have a shorter estimated value of progression-free time and a higher risk of progression than typical Grade II ependymomas. Giant cell ependymoma patients would have a higher risk of fatality than those with typical Grade II ependymomas. Definite pathology type and appropriate treatments were foundations of intramedullary Grade II ependymomas' managements.