STUDY DESIGN: A cross-sectional observational study involved the analysis of computed tomography (CT) scan data from 125 Indian subjects of 18 years or older with normal imaging findings. Scans were obtained from patients with head injuries as a part of the screening process along with brain CT scans.PURPOSE: To establish the dimensions of lateral masses of the atlas vertebrae in normal disease-free Indian individuals.OVERVIEW OF LITERATURE: Lateral mass fixation has become the standard of care in fixation of the supra-axial cervical spine. Many studies have investigated the dimensions of lateral masses in cadaveric specimens; however, studies involving the radiological morphometric analysis of the lateral masses of the atlas vertebra in living patients are lacking.METHODS: Subjects underwent craniovertebral junction CT scans during evaluations of head injury. All had normal radiology reports. The CT scans were obtained using a CT Philips Brilliance 64 machine (Philips, Amsterdam, Netherlands) with a slice thickness of 1 mm and then analyzed using Horos software ver. 2.0.2 (Horos Project, Annapolis, MD, USA) on a MacBook.RESULTS: Lateral masses of the atlas vertebrae were found to be larger in males than females and larger on the right than the left side. The angle of permissible medialization was found to be larger on the right side. The analysis of the average dimensions indicated the conventionally described screw positions to be safe.CONCLUSIONS: The present study provides information that may help to establish standard dimensions of lateral masses of the atlas vertebrae among the normal Indian population. We demonstrate that there is no significant difference when compared with the Western population. The results presented here will be of use to clinicians as they may inform preoperative planning for lateral mass fixation surgeries.
Brain ; Cadaver ; Cervical Atlas ; Craniocerebral Trauma ; Female ; Humans ; Male ; Mass Screening ; Observational Study ; Spine ; Standard of Care ; Tomography, X-Ray Computed

OBJECTIVE: To determine the relationship between cervical sagittal parameters and the degree of the cervical disc degeneration at each cervical level by using cervical plain radiographs and disc degeneration grading.METHOD: This study analyzed 110 patients with posterior neck pain. Cervical radiographic measurements included the occipito-cervical (O~C2) angle; sagittal Cobb angles of C1~C2, C2~C7; and sagittal vertical axis (SVA) of C1~C7 and C2~C7. The degenerations of cervical discs at each level were evaluated through Pfirrmann grading system by magnetic resonance images of the cervical spine. The correlations between the cervical sagittal measurements and the disc degeneration at each level were analyzed by Spearman's correlation.RESULTS: A significant correlation was found for the C2~C7 angle with disc degenerations at C2~C6 levels. O~C2 angle was correlated significantly with disc degenerations at C2~C4 and C5~C7 levels. There was significant correlation between C1~C2 angle and disc degeneration at C6~C7 level. No significant relationship was found between the cervical SVA and the cervical disc degeneration at all cervical levels.CONCLUSION: Cervical sagittal parameters representing cervical angles (C2~C7, O~C2, and C1~C2 angles) were significantly correlated with the degree of the cervical disc degeneration. These findings suggest that the loss of the natural cervical lordosis rather than loss of natural SVA could be correlated with progression of the cervical disc degeneration.
Animals ; Cervical Vertebrae ; Female ; Humans ; Intervertebral Disc Degeneration ; Kyphosis ; Lordosis ; Methods ; Neck Pain ; Spine

Involuntary movement of the cervical spine can cause damage to the cervical spinal cord. Cervical myelopathy may occur at an early age in involuntary movement disorders, such as tics. We report the case of a 21-year-old man with Tourette syndrome, who developed progressive quadriparesis, which was more severe in the upper extremities. The patient had abnormal motor tics with hyperflexion and hyperextension of the cervical spine for more than 10 years. High-signal intensity intramedullary lesions were observed at C3-4-5-6 level on T2 weighted magnetic resonance imaging. Examinations were performed for high-signal intensity intramedullary lesions that may occur at a young age, but no other diseases were detected. Botulinum toxin injection to the neck musculature and medication for tic disorders were administered. However, the myelopathy was further aggravated, as the involuntary cervical movement still remained. Therefore, laminoplasty was performed at C3-4-5-6, with posterior fixation at C2-3-4-5-6-7 to alleviate the symptoms. The neurological signs and symptoms improved dramatically. The management of tic disorders should be the first priority during treatment. However, surgical treatment may be necessary, if symptoms worsen after appropriate treatment.
Botulinum Toxins ; Cervical Cord ; Dyskinesias ; Humans ; Laminoplasty ; Magnetic Resonance Imaging ; Neck ; Quadriplegia ; Spinal Cord Diseases ; Spine ; Spondylosis ; Tic Disorders ; Tics ; Tourette Syndrome ; Upper Extremity ; Young Adult

OBJECTIVE: This study is a retrospective cost-benefit analysis of cervical anterior interbody fusion and cervical artificial disc replacement, which are the main surgical methods to treat degenerative cervical disc disease.METHODS: We analyzed 156 patients who underwent anterior cervical disc fusion and cervical artificial disc replacement from January 1, 2008 to December 31, 2009, diagnosed with degenerative cervical disc disorder. In this study, the costs and benefits were analyzed by using quality adjusted life year (QALY) as the outcome index for patients undergoing surgery, and a Markov model was used for the analysis. Only direct medical costs were included in the analysis; indirect medical costs were excluded. Data were analyzed with TreeAge Pro 2015™ (TreeAge Software, Inc, Williamstown, MA, USA).RESULTS: Patients who underwent cervical anterior fusion had a total cost of KRW 2501807/USD 2357 over 5 years and obtained a utility of 3.72 QALY. Patients who underwent cervical artificial disc replacement received 4.18 QALY for a total of KRW 3685949/USD 3473 over 5 years. The cumulative cost-effectiveness ratio of cervical spine replacement surgery was KRW 2549511/QALY (USD 2402/QALY), which was lower than the general Korean payment standard.CONCLUSION: Both cervical anterior fusion and cervical artificial disc replacement are cost-effective treatments for patients with degenerative cervical disc disease. Cervical artificial disc replacement may be an effective alternative to obtain more benefits.
Cervical Vertebrae ; Cost-Benefit Analysis ; Female ; Humans ; Quality-Adjusted Life Years ; Retrospective Studies ; Spinal Fusion ; Spine ; Total Disc Replacement

OBJECTIVE: To define optimal method that calculate the safe direction of cervical pedicle screw placement using computed tomography (CT) image based three dimensional (3D) cortical shell model of human cervical spine.METHODS: Cortical shell model of cervical spine from C3 to C6 was made after segmentation of in vivo CT image data of 44 volunteers. Three dimensional Cartesian coordinate of all points constituting surface of whole vertebra, bilateral pedicle and posterior wall were acquired. The ideal trajectory of pedicle screw insertion was defined as viewing direction at which the inner area of pedicle become largest when we see through the biconcave tubular pedicle. The ideal trajectory of 352 pedicles (eight pedicles for each of 44 subjects) were calculated using custom made program and were changed from global coordinate to local coordinate according to the three dimensional position of posterior wall of each vertebral body. The transverse and sagittal angle of trajectory were defined as the angle between ideal trajectory line and perpendicular line of posterior wall in the horizontal and sagittal plane. The averages and standard deviations of all measurements were calculated.RESULTS: The average transverse angles were 50.60º±6.22º at C3, 51.42º ±7.44º at C4, 47.79º ±7.61º at C5, and 41.24º ±7.76º at C6. The transverse angle becomes more steep from C3 to C6. The mean sagittal angles were 9.72º ±6.73º downward at C3, 5.09º±6.39º downward at C4, 0.08º ±6.06º downward at C5, and 1.67º ±6.06º upward at C6. The sagittal angle changes from caudad to cephalad from C3 to C6.CONCLUSION: The absolute values of transverse and sagittal angle in our study were not same but the trend of changes were similar to previous studies. Because we know 3D address of all points constituting cortical shell of cervical vertebrae. we can easily reconstruct 3D model and manage it freely using computer program. More creative measurement of morphological characteristics could be carried out than direct inspection of raw bone. Furthermore this concept of measurement could be used for the computing program of automated robotic screw insertion.
Cervical Vertebrae ; Female ; Humans ; Image Processing, Computer-Assisted ; Methods ; Pedicle Screws ; Spine ; Volunteers

OBJECTIVE: Using the CT three-dimensional reconstruction to measure the activity degree of atlanto-occipital joint and the atlantoaxial joint in different directions and its coupling movement in healthy volunteers, and three dimensional motion range of the maximum rotation position of the upper cervical spine of cervical spondylosis patients, and to analyze the differences, verifing the reliability of the method at the meantime. METHODS: From January 2014 to June 2015, 20 healthy adult subjects(healthy adult group), and 26 patients with cervieal spondylosis(cervical spondylosis group) were selected. In healthy adult group, there were 11 males and 9 females, aged from 22 to 26 years old with an average of (24.0±1.2) years, and in cervical spondylosis group, there were 24 males and 2 females, aged from 36 to 72 years old with an average of (52.8±8.6) years. Healthy adults underwent CT examination in neutral position, maximum right rotation, maximum right lateral bending, maximum flexion and extention, and cervical spondylosis patients underwent CT examination in neutral position, maximum right rotation. Then the software Mimics was used to reconstruct occiput (Oc), atlas(C1) and axial(C2) vertebral three-dimensional image. Three virtual non-collinear markers were positioned on prominent structures of foramen magnum, C1 and C2. The 3D spatial coordinates of these virtual anatomical markers entail the definition of an anatomical local coordinate system which represent the position and orientation of the bones. Segmental motions were calculated using Eulerian angle in three major planes, and the difference between cervical spondylosis group and healthy adult group were compared. Due to the inaccuracy in anatomical landmark idenrification, two groups were measured 3 times, and the reliability of the experimental metnod was verified by the intra-group correlation (intra-group ICC) and the inter-group correlation coefficient(inter-group ICC). RESULTS: Reliability verification results:the intra-group ICC and inter-group ICC results were all above 0.90, and the measurement method had high reliability. Three-dimensional activity of the upper cervical spine in healthy adults:the atlanto-occipital joint had(-6.8±1.5)° coupled left lateral bending and (8.9±2.0)° coupled extension in the maximum right rotation position, and the motion of atlanto-occipital joint had low activity[maximum was(5.3±2.6)°] in the remaining 3 positions; the rotation of atlanto-axial joint was(37.9±5.1)°, accounting for 52.34% of the total cervical spine activity[(72.4±5.0)°] in the maximum right rotation position, and rotational motion was still prominent in the remaining three positions. The relative translations of the upper cervical spine in all direction were small. The average axial rotation angle [(62.0±3.4)] ° of the total cervical spine in cervical spondylosis group was significantly lower than that in the healthy adult group, but the mean axial rotation angles of the atlanto-occipital and the atlantoaxial joint were not significantly different from those of the healthy adults(>0.05). CONCLUSIONS The three-dimensional CT reconstruction method has high reliability, which can be applied to measure the movement of spine. The upper cervical spine contributed the most to the direction of rotation, and the movement in all directions are accompanied by coupled motion in the other direction. There was no significant difference in the rotation of the upper cervical spine between cervical spondylosis patients and normal subjects.
Adult ; Aged ; Atlanto-Axial Joint ; Biomechanical Phenomena ; Cervical Vertebrae ; Female ; Humans ; Imaging, Three-Dimensional ; Male ; Middle Aged ; Range of Motion, Articular ; Reproducibility of Results ; Rotation ; Spine ; Tomography, X-Ray Computed ; Young Adult

We report two cases of subacute combined degeneration (SCD) caused by nitrous oxide (N₂O) gas intoxication, which is rarely reported in Korea. Two patients recreationally inhaled N₂O gas daily for several months. They presented with paresthesia of limbs, voiding difficulty, and gait disturbance. The initial vitamin B₁₂ levels were normal or decreased, but homocysteine levels of the two patients were increased. Magnetic resonance imaging of the cervical spine showed T2-weighted hyperintensity in the bilateral dorsal columns of the cervical spinal cord. Electromyography and somatosensory evoked potential tests for both patients suggested posterior column lesion of the spinal cord combined with sensorimotor polyneuropathy. According to these findings, we concluded that the two patients had SCD. The patient’s symptoms partially improved after cessation of N₂O gas inhalation and the receiving of vitamin B₁₂ supplementation therapy. As the incidence of recreational N₂O gas inhalation is increasing in Korea, physicians must be alert to the N₂O induced SCD in patients presenting with progressive myelopathy.
Cervical Cord ; Electromyography ; Evoked Potentials, Somatosensory ; Extremities ; Gait ; Homocysteine ; Humans ; Incidence ; Inhalation ; Korea ; Magnetic Resonance Imaging ; Nitrous Oxide ; Paresthesia ; Polyneuropathies ; Recreation ; Spinal Cord ; Spinal Cord Diseases ; Spine ; Subacute Combined Degeneration ; Vitamin B 12 ; Vitamins

It is difficult to distinguish Hirayama disease (HD) from other mimicking disorders in adolescent patients with distal upper limb weakness. The prevailing theory of HD postulates that the lower cervical cord is susceptible to compression during neck flexion because of insufficient growth of the dura relative to the spinal column. Confirmation of a dynamic change in the dorsal epidural space on magnetic resonance imaging (MRI) during neck flexion is essential for diagnosing HD. However, neck flexion MRI has not been routinely performed in juvenile patients with distal upper limb weakness in the absence of suspected HD. We report two cases of HD that were initially confused with other diseases because of insufficient or absent cervical flexion during MRI. Full-flexion MRI showed typical findings of HD in both cases. Our cases suggest that dynamic cervical MRI in the fully flexed position is necessary for evaluating suspected HD.
Adolescent ; Cervical Cord ; Diagnosis ; Epidural Space ; Humans ; Magnetic Resonance Imaging ; Neck ; Spinal Cord Diseases ; Spine ; Upper Extremity

STUDY DESIGN: Retrospective cohort study. PURPOSE: To evaluate surgical outcomes and complications of cervical spine fractures in ankylosing spondylitis (CAS) patients who were treated using either the posterior (P) or combined approach (C). OVERVIEW OF LITERATURE: Ankylosing spondylitis typically causes progressive spinal stiffness that makes patients susceptible to spinal fractures. CAS is a highly unstable condition. There is contradictory evidence regarding which treatment option, the posterior or the combined approach, yields superior clinical results. METHODS: A single institution database was reviewed for data in the period 1999 to 2015. All CAS patients who underwent posterior or combined instrumented fusion were enrolled. We analyzed demographic data, radiographic results, perioperative complications, and postoperative results. RESULTS: Thirty-three patients were enrolled (23 in the P group, 10 in the C group). All patients presented with neck pain after a fall. In the P group, mean operative time was 161.1 minutes (100–327 minutes), and mean estimated blood loss (EBL) was 306.4 mL (50–750 mL). In the C group, 90% of patients underwent a staged procedure, typically with posterior surgery first. Mean EBL was 124 mL (25–337 mL). For posterior surgery, mean EBL was 458.3 mL (400–550 mL). EBL of posterior surgery in the C group was higher but this difference was not significant (p=0.16). Postoperative complication rate was higher in the C group but this difference was not significant (50% vs. 17.4%, p=0.09). In the follow-up period, no late reoperations were performed. Patients who underwent C surgery had a higher rate of neurological improvement but this difference was not significant (p=0.57). CONCLUSIONS: Both P and C provided good clinical results. P surgery had lower EBL, lower postoperative complication rate, and shorter length of stay than C surgery; none of these differences were statistically significant.
Cervical Vertebrae ; Cohort Studies ; Female ; Follow-Up Studies ; Humans ; Length of Stay ; Neck Pain ; Operative Time ; Postoperative Complications ; Reoperation ; Retrospective Studies ; Spinal Fractures ; Spine ; Spondylitis, Ankylosing

OBJECTIVES: Patients with head and neck cancer (HNC) have a high risk of sarcopenia, which is associated with poor prognosis. Skeletal-muscle area and index at the third lumbar (L3) vertebra level (L3MA and L3MI) are recommended for the detection of sarcopenia. However, L3 level is not included in many imaging protocols and there are no data for optimal levels and cutoffs for the diagnosis of sarcopenia in head and neck computed tomography (HNCT) scans. Our aim was to assess the relationship between cervical paravertebral muscle values and L3MI and to investigate optimal level to diagnose sarcopenia on HNCTs. METHODS: Patients with HNC (n=159) who underwent positron emission tomography-CT for tumor staging were retrospectively analyzed. On CT images, paravertebral and sternocleidomastoid muscle areas at second (C2), third (C3), and fourth (C4) cervical vertebrae levels (C2MA, C3MA, C4MA, SCMA) and L3MA were measured. Cross-sectional areas were normalized for stature (muscle area/height square) and muscle index (C2MI, C3MI, C4MI, SCMI, L3MI) values were obtained. Spearman correlation and linear regression analyses were used for assessing correlations. To calculate the diagnostic performance of SCMI, C2MI, C3MI, and C4MI for the diagnosis of sarcopenia with respect to the cutoffs of L3MI, receiver operating characteristic (ROC) analysis was used. RESULTS: Males had significantly higher muscle areas than females. Although C2MI, C3MI, C4MI, and SCMI values all showed very strong and significant correlation with L3MI (P<0.001). According to the ROC analysis, the best discriminative for sarcopenia was C3MI in males (area under curve [AUC], 0.967) and SCMI in females (AUC, 0.898). CONCLUSION: C2MI, C3MI, C4MI, and SCMI values can be used as alternatives for the diagnosis of sarcopenia in routine HNCT examinations.
Body Mass Index ; Cervical Vertebrae ; Diagnosis ; Electrons ; Female ; Head and Neck Neoplasms ; Head ; Humans ; Image Processing, Computer-Assisted ; Linear Models ; Male ; Neck ; Neoplasm Staging ; Prognosis ; Retrospective Studies ; ROC Curve ; Sarcopenia ; Spine