Percutaneous C-Arm Free O-Arm Navigated Biopsy for Spinal Pathologies: A Technical Note.

BACKGROUND: Percutaneous biopsy under computed tomography (CT) guidance is a standard technique to obtain a definitive diagnosis when spinal tumors, metastases or infections are suspected. However, specimens obtained using a needle are sometimes inadequate for correct diagnosis. This report describes a unique biopsy technique which is C-arm free O-arm navigated using microforceps. This has not been previously described as a biopsy procedure. CASE DESCRIPTION: A 74-year-old man with T1 vertebra pathology was referred to our hospital with muscle weakness of the right hand, clumsiness and cervicothoracic pain. CT-guided biopsy was performed, but histopathological diagnosis could not be obtained due to insufficient tissue. The patient then underwent biopsy under O-arm navigation, so we could obtain sufficient tissue and small cell carcinoma was diagnosed on histopathological examination. A patient later received chemotherapy and radiation. CONCLUSIONS: C-arm free O-arm navigated biopsy is an effective technique for obtaining sufficient material from spine pathologies. Tissue from an exact pathological site can be obtained with 3-D images. This new O-arm navigation biopsy may provide an alternative to repeat CT-guided or open biopsy.

Characteristics of Cervical Spine Motion in Different Types of Cervical Alignment: Kinematic MRI Study.

STUDY DESIGN: Retrospective study. OBJECTIVE: To evaluate how each type of sagittal cervical alignment affects the motion of the upper and subaxial cervical spine using kinematic magnetic resonance imaging. SUMMARY OF BACKGROUND DATA: The sagittal malalignment of the cervical spine from degeneration in the subaxial cervical spine reflects a disruption in the kinematic properties of the cervical spine and affects the motion of adjacent segments. Changes in the sagittal parameters and kinematics of the upper cervical spine and upper thoracic spine due to the kyphosis are unknown. METHODS: Kinematic magnetic resonance imaging of the cervical spine in neutral position from 311 patients, including 90 lordotic, 90 straight, 90 global kyphotic, and 41 segmental kyphotic were analyzed. The lordotic angle at the upper and lower cervical spine, and T1 slope were measured in the neutral position and again in flexion and extension for dynamic analysis. RESULTS: The number of levels with significant disk degeneration was higher in the global kyphosis group. In the global kyphosis group, neutral sagittal parameters showed some characteristics of compensation to the malalignment. Compared with the lordotic group, patients with global kyphosis demonstrated significantly higher lordotic angle of the upper cervical spine and more horizontal T1 slope. The dynamic evaluation showed greater range of motion of the entire cervical spine and subaxial cervical spine in younger patients. However, we still found greater range of motion of the occipito-atlanto-axial complex in global kyphosis, even when controlling for age and number of levels with significant disk degeneration. CONCLUSION: Sagittal malalignment of the cervical spine affects all parts of the cervical motion complex. The global kyphotic alignment of subaxial cervical spine affects the kinematic properties of the occipito-atlanto-axial complex and upper thoracic spine to compensate for the alteration of cervical alignment. These differences are not seen in straight and segmental kyphosis. LEVEL OF EVIDENCE: Level 3.

MRI kinematic analysis of T1 sagittal motion between cervical flexion and extension positions in 145 patients.

PURPOSE: Although the T1 vertebra is considered as an important factor of cervical balance, little is known about its motion between flexion and extension. The purpose of present study was to analyze the T1 sagittal motion using kinematic magnetic resonance imaging (kMRI), and to identify factors that relate to T1 sagittal motion. METHODS: We retrospectively analyzed 145 kMR images taken in weight-bearing neutral, flexion and extension positions. Cervical balance parameters were evaluated in each position. The degree of T1 sagittal motion was defined as [(T1 slope at extension) - (T1 slope at flexion)]. All patients were divided into three groups: Positive group (T1 followed the head motion, T1 sagittal motion > 5°), Stable group (5 ≥, ≥ - 5) and Negative group (T1 moved in the opposite direction from the head motion, > - 5). The groups were compared and multivariate logistic regression analysis was calculated. RESULTS: There were 57 (40%) patients in the positive, 56 (39%) in the stable and 32 (22%) in the negative group. The positive group had the largest C2-7 sagittal vertical axis in flexion (p < 0.001) and the shortest in the extension (p = 0.023). Similar trends were seen in cranial tilt and cervical tilt. The value of T1 height < 27 mm was a significant independent factor for the negative group (p = 0.008, adjusted odds ratio = 5.958). CONCLUSION: Based on T1 sagittal motion, 40% of the patients were classified in positive group (the T1 vertebra followed the head motion in flexion and extension), and 20% were classified in the negative group (the T1 vertebra moved in the opposite direction from the head motion). T1 height < 27 mm was a potential predictor of negative group.

Can multi-positional magnetic resonance imaging be used to evaluate angular parameters in cervical spine? A comparison of multi-positional MRI to dynamic plain radiograph.

PURPOSE: To test the reliability and validity of the multi-positional magnetic resonance imaging (MRI) in measuring cervical angular parameter using the standard dynamic cervical X-ray as a reference. METHODS: All patients who underwent both cervical dynamic plain radiograph and multi-positional MRI on the same day between 2010 and 2016 were included in this study. The C2-7 angle and the segmental angles of the C2-3 to C6-7 segments were measured in all three positions (neutral, flexion, and extension) using multi-positional MRI and dynamic radiograph. The Pearson's correlation coefficients and linear regression analysis were used for statistical analysis. RESULTS: 46 patients were enrolled in this study. All angular parameters showed significant positive correlation between multi-positional MRI and dynamic X-ray (p < 0.05). The angle of C2-7 showed significantly positive correlation between multi-positional MRI and X-ray (r = 0.552-0.756). All segmental angles from C2-3 to C6-7 showed moderate correlation (r = 0.401-0.636). The linear regression analysis showed that C2-7 angles and all angular parameters had significant correlation between multi-positional MRI and dynamic X-ray (p < 0.05, R 2 = 0.107-0.571). CONCLUSIONS: The C2-7 angle and segmental cervical angles measured by multi-positional MRI were valid, and reliability substituted the dynamic X-ray measurement within the acceptable range of error. Multi-positional MRI can be used as a reliable tool for angular parameter measurement and detection of angular instability in the cervical spine.

Can C7 Slope Substitute the T1 slope?: An Analysis Using Cervical Radiographs and Kinematic MRIs.

STUDY DESIGN: Retrospective analysis of consecutive 45 radiographs and 120 kinematic magnetic resonance images (kMRI) OBJECTIVE.: The aim was to assess the visibility of C7 and T1 endplates on radiographs, and to verify the correlation between C7 or T1 slope and cervical balance parameters using kMRI. SUMMARY OF BACKGROUND DATA: Because the T1 slope is not always visible due to the anatomical interference, several studies have used C7 slope instead of T1. However, it is still unclear whether the C7 endplate is more visible on radiographs than T1, and if C7 slope has similarity with T1 slope. METHODS: The endplate visibility was determined using weight-bearing radiography. Subsequently, using weight-bearing MR images, the C7 slope of upper and lower endplate, T1 slope, C1 inclination, C2 slope, atlas-dens interval (ADI), C2-C7 lordotic angle, cervical sagittal vertical axis (cSVA), cervical tilt, cranial tilt, neck tilt, thoracic inlet angle (TIA) were measured, for the analysis of correlation between three types of slopes and cervical balance parameters. RESULTS: 82% of the upper C7, and 18% of T1 endplate were clearly visible. The upper C7 endplate was significantly visible, whereas T1 endplate was significantly invisible (residual analysis, P < 0.01). Linear regression analysis showed correlation between the upper C7 slope and T1 slope (R = 0.818, P < 0.01) and, lower C7 slope and T1 slope (R = 0.840, P < 0.01). T1 slope significantly correlated with neck tilt, TIA, C2-C7 angle, cSVA, cervical and cranial tilt, but not with the C1 inclination, C2 slope, and ADI. Upper and lower C7 slopes showed the close resemblance with T1 slope in terms of correlation with those parameters. CONCLUSION: Both, upper and lower C7 slope correlated strongly with T1 slope and showed similar relationship with cervical balance parameters as T1 slope. Therefore, C7 slope could potentially substitute T1 slope, especially upper C7 slope due to the good visibility. LEVEL OF EVIDENCE: 3.

Do modic changes, disc degeneration, translation and angular motion affect facet osteoarthritis of the lumbar spine.

The objective of the study is to identified the correlation between Modic changes (MCs), disc degeneration, motions (translation and angulation) and facet osteoarthritis in lumbar spine. 425 patients who underwent multi-positional lumbar MRI were reviewed. A total of 2250 lumbar spinal segments in neutral position were evaluated for MCs, disc degeneration grading, translation and angulation motion, and facet osteoarthritis. The chi-square test, Kruskal-Wallis, Mann-Whitney U test, Pearson's correlation and linear regression were used to test for statistically significant difference between parameters. MCs type 2 showed the most translational motion. The presence of MCs was significantly correlated with advanced disc degeneration (grade 4-5, Odds ratio 6.29, 95% CI 4.48-8.83) and the presence of facet osteoarthritis (Odds ratio 9.50, 95% CI 6.18-14.62). The presence of facet osteoarthritis had significantly more translation motion than non-osteoarthritis facet (p=0.04). The facet osteoarthritis grade was positively correlated with disc degeneration grade (r=0.309, p-value<0.001). The facet osteoarthritis correlated with the presence of MCs and more translation motion. The severity of facet osteoarthritis was correlated with the advanced disc degeneration. The MCs, translation motion, and disc degeneration were the significant parameters which affected lumbar facet osteoarthritis.