Purpose
This study aimed to compare the clinical effectiveness and potential benefits of ultrasound (US)-guided versus fluoroscopy (FL)-guided cervical retrolaminar block (RLB) in patients with cervical facet joint pain.
Materials and Methods
A total of 27 patients aged 40 years or older who were diagnosed with cervical facet joint syndrome based on physical examination and imaging modalities were included. 12 patients of group I treated with US-guided RLB and 15 patients of group II treated with FL-guided RLB. The position of the needle and the distribution of contrast agent were confirmed using fluoroscopic images, and the changes in numeric rating scale (NRS) and neck disability index (NDI) before and 2 weeks after the procedure were compared in the two groups.
Results
Radiologically, the target agreement of needle placement in group I was 75%. There was no difference in contrast medium spread between the two groups. Clinically, the mean NRS improved from 7.08±0.52 to 3.08±0.90 in group I (p=0.01) and from 7.20±0.56 to 3.33±0.72 in group II (p=0.01). The mean NDI decreased from 41.67±2.27 before the procedure to 20.83±2.33 after the procedure in group I (p=0.01), and from 40.87±2.61 before the procedure to 21.67±2.02 after the procedure in group II (p=0.01), with no difference between the two groups.
Conclusions
US-guided cervical RLB is an effective, radiation-free alternative to FL-guided RLB for managing cervical facet joint pain, offering comparable pain relief and functional improvement.

Objective
To compare the pull-out strength of polyaxial general screws and rescue screws when inserted into the lateral mass through cadaveric biomechanical experiment
Materials and Methods
Twenty three segments of the human cervical spine (from C3 to C7) were prepared. Two biomechanical studies were progressed. In the first experiment (13 segments), each segment was instrumented with 3.5×12 mm polyaxial screws on both sides. In one side, the inserted screw was removed and then the rescue screw was inserted to the same screw hole. In the second experiment (10 segments), all segments were instrumented with 3.5×12 mm polyaxial screws on both sides and all screws were removed. In one side, removed same screw was reinserted and in the other side, the rescue screw was inserted without change of the screw trajectory. All specimens were fixed to the specially designed frame with the cement. Universal Material Test Machine (Mini Bionix 858) was used to assess the pull-out strength of the screws. All data were compared with non-parametric paired test (Wilcoxon’s signed rank test).
Results
There was no crack or fracture around the screw hole. No significant difference was noted between the original screws (not reinserted) and the rescue screws in the first experiment (p=0.753). There is no significant difference between the same screw reinsertion and the conversion to the rescue screw (p=0.646).
Conclusions
The overall results of this study showed the conversion to the rescue screw with the same screw trajectory could offer no biomechanical advantage over reinsertion of the same screw. In case of secure screw hole after removal of the screw, the reinsertion of the same screw could be recommended.

Purpose
To analyze the risk of a fall in patients with cervical spondylotic myelopathy (CSM) and its clinical significance.
Materials and methods
40 patients with CSM who visited to our hospital From May 2014 to April 2015 were enrolled in this study. After confirmation of CSM based on MRI and Physical examination, patients were divided into three groups according to m-JOA score (Group A; severe; score <8, Group B; moderate; score 8-12, Group C; mild score >13). All patients enrolled in this study performed 4 functional assessment test including Alternative-Step Test (AST), Six-MeterWalk Test (SMT), Sit-to-Stand test (STS), and Timed Up and Go test (TUGT) to assess the risk of a falls (ROF).
Results
There were statistical significance between m-JOA score and ROF except for SMT. Average time (seconds) for STST was 26.12±5.60, 20.99±5.92 and 15.37±3.41 in group A, B, C, respectively (p=0.001), Although average time(s) for AST was 16.81±3.83, 14.39±4.05 and 12.37±3.95 in group A, B, C with no statistical significance (p=0.106), there was a significance between the value of Group A and C (p=0.047). Average time(s) for TUGT was 31.86±17.05, 15.09±4.59,18.04±9.32 in group A, B, C, respectively, showed statistical significance (p=0.000).
Conclusion
According to its severity of myelopathy, it took more time to carry out each ROF assessment tests. Among 4 functional assessment tests of ROF, STST showed the most highest correlation with mJOA socre. Careful attention of ROF will be needed in patients with myelopathy.

Background
Cervical kyphosis is frequently observed in the patients without axial neck pain and sigmoid curvatures are parts of the variety of cervical kyphosis. Purpose: This study was designed to investigate the characteristics of the static and dynamic alignment of the cervical spine with sigmoid configurations.
Methods
Figty patients without changes of the cervical curvatures after subsidence of axial neck pain were enrolled in this study. Based on the alignment of cervical spine on lateral radiographs, cervical alignments were classified: kyphotic (K), kypho-lordotic (KL), lordo-kyphotic (LK), and Lordotic (L) group. The sagittal alignment angles and each segmental angle were measured using the Harrison method on neutral, flexion, and extension-lateral radiographs.
Results
The mean ratio of segmental ROM to C2-7 ROM revealed a similar pattern across the cervical levels without statistical difference between the groups. In the KL and LK group, the linear graphs for the mean ratio of segmental angles to C2-7 angles in flexion and extension showed a mirror image with respect to the C4-5 level. The lordotic components of both curves demonstrated larger ratio of segmental angles in flexion than the kyphotic components. The kyphotic components of both curves demonstrated larger ratio of segmental angles in extension than the lordotic components.
Conclusions
The lordotic and kyphotic components regardless of the type of sigmoid curvatures seem to adhere to constant dynamic behavior during flexion and extension. Therefore, the KL and LK cervical alignments may have the opposite dynamic behaviors in the high and low cervical levels.

Purpose
To compare the difference of cervical alignment between cervical lateral radiograph and whole-spine lateral radiograph by the effects of radiographic position and to assess the effect of the shoulder flexed position to cervical lordotic curvature and head position.
Materials and Methods
We retrospectively evaluated 43 asymptomatic adult patients who were taken horizontal gazing standing cervical and whole-spine lateral radiograph simultaneously from Sep. 2008 to Dec. 2009. Cervical lateral radiograph was taken with the arms extended and hand gently clasped on both side and whole-spine lateral radiograph was taken in the position that subject were relaxed standing with fists-on-clavicles position. Cervical sagittal alignment were analyzed the following parameters. (1) Gore angle (GA, C2-7 angle); (2) Cobb angle (CA, C2-7 angle); (3) translation distance (TD, distance of C2 compared with vertical line through the posterior-inferior body of C7); (4) McGregor angle (MA, angle between McGregor line and horizontal line).
Results
The mean of GA and CA in cervical radiograph were -12.64° and -9.96°, whereas -7.12° and -4.98° in wholespine radiograph. The mean TD and MA were in cervical radiograph were 16.95mm and 7.15°, whereas, 14.97mm and 6.54° respectively in whole-spine radiograph.
Conclusion
Our study showed the significant differences of cervical alignment and head position between standing cervical lateral and whole-spine lateral radiograph. The radiographic posture of whole-spine lateral radiograph with horizontal gazing and fists-on-clavicles position make cervical alignment and head position less lordotic and posterior translation compared to cervical radiograph.