The Relationship Between Preoperative Cervical Sagittal Balance and Clinical Outcome of Patients With Hirayama Disease Treated With Anterior Cervical Discectomy and Fusion

Objective: Anterior cervical discectomy and fusion (ACDF) is a common surgical method used to treat patients with Hirayama disease. And sagittal balance indexes have been revealed to be predictors of clinical outcomes in patients with cervical diseases, but their relationships with ACDF-treated Hirayama disease outcomes remain unknown. The purpose of this study is to evaluate the relationship of preoperative cervical sagittal balance indexes and clinical outcomes in ACDF-treated Hirayama disease patients.Methods: Eighty patients with Hirayama disease treated by ACDF were reviewed retrospectively. Six cervical sagittal balance parameters were collected including Cobb angle, T1 slope, C1–7 sagittal vertical axis (SVA), C2–7 SVA, center of gravity of the head (CGH)-C7 SVA, range of motion. The recovery outcomes of the patients were divided into 2 groups by Odom score and the differences in recovery between the 2 groups were confirmed by electromyography. The correlation between imaging parameters and postoperative outcome was evaluated with logistic regression. The receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) were used to evaluate the significant result of logistic regression and the optimal diagnostic value.Results: Only 2 parameters, Cobb angle and CGH-C7 SVA, showed statistical correlation with the postoperative outcome assessment by logistic regression. AUC of Cobb angle and CGH-C7 SVA were 0.559 and 0.702 respectively. The optimal predictive threshold was 1.50° and 5.40 mm, respectively.Conclusion: A larger Cobb angle and smaller CGH-C7 SVA seemed to correlate with a better postoperative outcome. These 2 factors could be used to predict the outcome of surgical treatment of Hirayama disease preoperatively.

Sagittal balance of the cervical spine

The treatment of adult cervical deformity continues to be complex with high complication rates. However there are many new advancements and overall patients do well following surgical correction. To date there are now many types of cervical deformity that have been classified and there exists a variety of surgical options. These recent advances have been developed in the last few years and the field continues to grow at a rapid rate. Thus, the goal of this article is to provide an updated review of cervical sagittal balance including; cervical alignment parameters, deformity classification, clinical evaluation, with both conservative and surgical treatment options.

Subaxial Lordosis Loss and Influence Factors After Posterior Atlantoaxial Fusion

Summary of Background Data: Cervical sagittal balance, an important evaluation index of cervical physiological function and surgical efficacy. Subaxial kyphosis after atlantoaxial fusion is negatively associated with worse clinical outcome and higher incidence of lower cervical disc degeneration. Objectives: This study aimed to confirm the factors that influence subaxial lordosis loss after posterior atlantoaxial fusion. Methods: We performed a retrospective review of all patients following posterior C1-C2 fusion for atlantoaxial dislocation between January 2015 and December 2017. All charts, records, and imaging studies were reviewed for each case, and preoperative, immediate postoperative, and final follow-up plain films were evaluated. Comparing final follow-up and preoprative C2-C7 angle, patients were divided into two groups for further comparison: subaxial lordosis loss group and subaxial lordosis increase group.Results: A total of 18 patients were included in the review, with an average radiographic follow-up of 8.4 ± 3.7 months (range, 6 to 17 months). Subaxial lordosis loss was observed in 5 cases (27.8%) at the final follow-up, whereas 13 cases had an increase of subaxial lordosis. The cervical sagittal parameters of preoperative and final follow-up between two groups were compared, the preoperative C2-C7 angle of the subaxial lordosis loss group was bigger than the subaxial lordosis increase group (27.6°±10.5° vs 10.5°±10.5°, P<0.05), but there was no statistical difference in other parameters. Univariate chi-square analysis showed that reduction of subaxial lordosis after posterior atlantoaxial fusion was associated with preoperative C2-C7 angle ≥20° (χ2=4.923, P=0.026). However, Logistic regression analysis showed that the preoperative C2-C7 angle ≥20° was not an independent risk factor (OR=0.147, P=0.225). Conclusion: Our study demonstrates that subaxial lordosis loss may occur after posterior atlantoaxial fusion, and preoperative C2-C7 angle ≥20° was a risk factor of postoperative loss of subaxial lordosis.

Relationship between odontoid fracture angle and cervical sagittal balance

Background: Fractures can occur in various locations within the odontoid process with differing orientations. However, little is known about what factors contribute to the anterior versus posterior angles/orientation of these fractures. Methods: We evaluated 74 patients with odontoid fractures (2013–2018) from a single-institution. Patients’ fracture angles/orientations were measured on computed tomography studies, and were grouped into oblique posterior (OP) or oblique anterior (OA) groups. We also took into account cervical sagittal balance utilizing upright x-rays. Other variables studied included patients’ ages, sagittal balance measurements, and the mechanisms of injury. Results: Fracture angles were significantly steeper in the OP group. OP fractures had larger C2-C7 sagittal vertical axis, occiput-C2 angles, and occiput-C7 angles versus anteriorly oriented fractures. In our linear regression model, advanced age and large occiput-C2 angles were predictive of the odontoid fracture angle. Patients who sustained ground-level falls also had significantly steeper fracture angles versus those involved in motor vehicle accidents. Conclusion: The odontoid tends to fracture at a steep, posterior angle in elderly patients who demonstrate a large positive sagittal balance when the head is extended following a ground-level falls.

COMPARATIVE ANALYSIS OF CERVICAL SAGITTAL BALANCE WITH RADIOGRAPHS IN DIFFERENT POSTURES

ABSTRACT Objective: To compare the cervical sagittal balance in groups of patients submitted to lateral radiographs of the cervical segment, with the upper limbs in two different positions. Methods: This is a cross-sectional, quantitative, prospective, descriptive study using radiographic analysis of 100 adult individuals, aged between 20 and 70 years. Two lateral radiographs were taken of each patient, one image with the upper limbs crossed over the trunk (flexed elbows) and the other with the upper limbs elevated in front (extended elbows). All patients answered a questionnaire about age, sex, presence of pain in the cervical spine, as well as degree of pain based on the Likert scale. The radiographic parameters evaluated were the COBB angle (Cobb), thoracic inlet angle (TIA), T1 slope, neck tilt and distance from the center of gravity (COG) of the skull to C7 (COG-C7) with the elbows in extension (Ext) and flexion (Flex). A p-value of less than 0.05 was considered a statistically significant difference. Results: Sixty patients were female (60%) and forty were male (40%). The data analysis obtained showed statistical significance in Cobb Flex vs. Cobb Ext (p = 0.000), TIA Flex vs. TIA Ext (p = 0.000), T1 Flex vs. T1 Ext (p = 0.000), Neck tilt Flex vs. Neck tilt Ext (p = 0.000), and COG-C7 Flex vs. COG-C7 Ext (p = 0.000). Conclusion: There was statistical significance in relation to the positioning of the upper limbs in the lateral radiographs, yielding higher values in the angulations with the limbs raised towards the front (extended elbows). Level of evidence II; Prospective Comparative Study.