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Objective
The aim of this study was to measure the movement of the cervical spine in healthy volunteers and patients with cervical spondylosis (CS) and describe the actual motion of the cervical spine using a three-dimensional (3D) CT reconstruction method. The results can enrich current biomechanical data of cervical spine and help to find the dif...
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Objectives:
Exposing the clivus and upper cervical spine should, ideally, provide an adequate surgical field in which the surgeon can safely decompress and stabilize the craniovertebral junction (CVJ). We present a series of four cases with a narrative review of the literature in which Median Labiomandibular Glossotomy was used to treat CVJ disorde...
Citations
... Both the anterior and posterior sections were accurately elevated by 5 mm, resulting in a 4.8° variance compared to the lateral aspects on a 12 cm diameter of the top plate. This design choice was made to accommodate the greater range of flexion and extension movements as opposed to lateral flexion 19,20 . d) Photograph of the apparatus with a specimen embedded during the experimental run. ...
The data on the use of a one- or two-screw technique (1S, 2S) for ventral osteosynthesis of type II dens fractures are contradictory. The aim was to design an apparatus to mimic the physiological conditions and test stability with 1S, 2S, and a headless compression screw (HCS) for osteosynthesis of artificially created type II odontoid fractures. The apparatus was mounted on a Zwick materials testing machine. A total of 18 C1–2 specimens were stratified into three groups (1S, 2S, HCS). Odontoid fractures were artificially created, and osteosynthesis was performed. Each specimen was tested at loads increasing from 1 to 40 N. Screw loosening was observed visually, by fatigue data, and by a camera tracking system. Analysis of the Zwick data and the camera data revealed a significant higher stability after 2S compared to 1S and HCS treatment (Zwick data: p = 0.021, camera data: p < 0.001), while visible screw loosening showed a superiority of the 2S only over HCS (p = 0.038). The developed apparatus allowed the dynamic study of the atlantoaxial joint with a high approximation to physiological conditions. The results demonstrated superiority of the 2S over the 1S and HCS in biomechanical stability in the treatment of type II odontoid fractures.
... In this case, neck rotation was limited despite preserved cervical retroflexion. The range of motion of neck rotation in adults without cervical spine involvement is approximately 70° to one side [10,11], so this case is clearly small. Considering that at least 60% of neck rotation is produced by the upper cervical spine [11], a range of motion of 18° in this case may raise suspicion of limited upper cervical motion. ...
... The range of motion of neck rotation in adults without cervical spine involvement is approximately 70° to one side [10,11], so this case is clearly small. Considering that at least 60% of neck rotation is produced by the upper cervical spine [11], a range of motion of 18° in this case may raise suspicion of limited upper cervical motion. Although there is no evidence to support neck rotation as a screening for limited upper cervical motion, it may be useful as a reference to prompt further evaluation by radiography or CT. ...
Background
The upper cervical spine is a major focus of damage by rheumatoid arthritis (RA). Specific screening for mobility of the upper cervical spine, which is essential for direct laryngoscopy, is lacking. Herein, we present a case of RA with Cormack-Lehane grade IV, which was not predicted by preoperative examination.
Case presentation
A 66-year-old woman with RA was scheduled for a right total knee arthroplasty and right elbow synovectomy. She had a long history of RA without symptoms related to the cervical spine or spinal cord. Although physical examination suggested moderate risk of difficult intubation with preserved cervical retroflexion, her Cormack-Lehane classification was grade IV under muscle relaxation. Bony integration of the occiput to axis was considered to be the main cause of difficult direct laryngoscopy, and restricted neck rotation was found postoperatively.
Conclusions
RA patients may have limited upper cervical spine motion despite normal cervical retroflexion.
... A compound movement that combined rotation and lateral bending was observed. It seems that the movement to be performed depends on the principal plane and that this leads to a specific motor organization in the associated planes [18]. ...
... 7 Physiologically, cervical rotation is not uniformly distributed between the upper and lower cervical spinal regions, with upper cervical (UC) accounting for 60% of the available motion. [8][9][10] A number of person-dependent characteristics have been proposed that may influence ROM in the cervical spine. Habits and postures related with occupational demands such as sitting hours or use of data display screens are a risk factor for developing neck pain. ...
... [19][20][21][22] Full axial rotation ROM at C1-C2 is generally accepted to be approximately 40-45°, 23 with most in vivo studies reporting values between 36° and 41°. 10,[24][25][26][27][28] However, there is a wide variability in the literature regarding the amount of UC rotation among the UC rotation ROM tests: the flexion rotation test (FRT), the side-bending rotation test (SBRT) and the C0-C2 axial rotation test (C0-C2ART). For example, UC rotation found in the FRT was described three times larger than in the C0-C2ART. ...
Background
Active cervical spine rotation (ACROM Rot) shows cervical rotation and flexion rotation test (FRT); side-bending rotation test (SBRT) and upper cervical axial rotation test (C0–C2ART) are described to measure upper cervical rotation. The objectives of this study are (1) to describe the normal range of motion (ROM) of ACROM Rot, and the ROM in FRT, SBRT and C0–C2ART tests; (2) to explore the correlation among the four tests and (3) to investigate the influence of age and sex in their ROM.
Methods
A cross-sectional study was carried out with healthy volunteers from 18 to 75 years of age. Tests were measured using a CROM device and a bubble inclinometer. Descriptive analysis was performed to establish normative data for the ROM tests. Correlation analysis was conducted to understand the relation between upper and global cervical rotation ROM and among the three upper cervical rotation tests. Linear regression models were developed to understand the influence of age and sex in the ROM of all tests.
Results
Normative values were obtained from 122 healthy volunteers (50% male), by sex and age strata. The degree of correlation ranged between 0.582 (p < 0.01) for FRT and ACROM Rot left and 0.217 (p < 0.05) for SBRT and C0–C2ART left. Linear regression models showed the influence of sex for ACROM Rot right (men −4.64° less than women), SBRT (men −4.1° less than women) left and C0–C2ART right and left (men −2.24° and −1.78° less than women). The age influenced rotation ROM with a decrease for every 10 years of −2.11° and −1.96° for ACROM Rot right and left, of −1.72° and −1.26° for FRT right and left and −0.58° and −0.41° for C0–C2ART right and left in the linear regression models. No association was found between age and SBRT (p = 0.63 for right SBRT and p = 0.49 for left SBRT).
Conclusion
Weak-to-moderate correlation was found between the upper cervical spine rotation tests and with the ACROM. Women had a larger ROM in ACROM Rot right, SBRT left and C0–C2ART. Decreases in ROM related with age were observed for ACROM Rot, FRT and C0–C2ART but not for SBRT.
... The specialized anatomy of the upper cervical spine (UCS), comprised of the occipital-atlas (C0-C1) and atlasaxis (C1-C2) segments, produces complex three-dimensional movements and subsequently is the most mobile region of the spine 1 . These segments produce approximately 60% of the cervical axial rotation 1,2 , and the greatest axial rotation of any segments in the spine 3 . UCS axial rotation is mainly restrained by the alar ligament system, connecting the occipital bone to the odontoid process of C2 bilaterally 4 . ...
... Their rationale was that the tightening of alar ligaments would impact the available ROM in the different coupled movements associated with UCS axial rotation. The combination of axial rotation and contralateral lateral bending is considered the coupled movement for the UCS rotation 2,5,6,[9][10][11][12] . Coupled rotation + extension + contralateral lateral bending, and axial rotation alone, showed larger UCS rotation ROM than simultaneous flexion, axial rotation and ipsilateral lateral bending) in an in vitro study 13 . ...
... Lorente et al. (2022) 13 showed that the rotation + extension + contralateral lateral bending ROM was larger than the rotation + flexion + ipsilateral lateral bending combination. Several studies have not frequently considered the C0-C1 segment when evaluating UCS rotation 2,8,17 . However, in vivo C0-C1 axial rotation to one side has been measured with values of 1.7° ± 1.5°5, and 2.5° ± 1.0°6 in samples with an average of 24.3 and 23.6 years respectively. ...
The purpose of this study is to compare axial rotation range of motion for the upper cervical spine during three movements: axial rotation, rotation + flexion + ipsilateral lateral bending and rotation + extension + contralateral lateral bending before and after occiput-atlas (C0–C1) stabilization. Ten cryopreserved C0–C2 specimens (mean age 74 years, range 63–85 years) were manually mobilized in 1. axial rotation, 2. rotation + flexion + ipsilateral lateral bending and 3. rotation + extension + contralateral lateral bending without and with a screw stabilization of C0–C1. Upper cervical range of motion and the force used to generate the motion were measured using an optical motion system and a load cell respectively. The range of motion (ROM) without C0–C1 stabilization was 9.8° ± 3.9° in right rotation + flexion + ipsilateral lateral bending and 15.5° ± 5.9° in left rotation + flexion + ipsilateral lateral bending. With stabilization, the ROM was 6.7° ± 4.3° and 13.6° ± 5.3°, respectively. The ROM without C0–C1 stabilization was 35.1° ± 6.0° in right rotation + extension + contralateral lateral bending and 29.0° ± 6.5° in left rotation + extension + contralateral lateral bending. With stabilization, the ROM was 25.7° ± 6.4° (p = 0.007) and 25.3° ± 7.1°, respectively. Neither rotation + flexion + ipsilateral lateral bending (left or right) or left rotation + extension + contralateral lateral bending reached statistical significance. ROM without C0–C1 stabilization was 33.9° ± 6.7° in right rotation and 28.0° ± 6.9° in left rotation. With stabilization, the ROM was 28.5° ± 7.0° (p = 0.005) and 23.7° ± 8.5° (p = 0.013) respectively. The stabilization of C0–C1 reduced the upper cervical axial rotation in right rotation + extension + contralateral lateral bending and right and left axial rotations; however, this reduction was not present in left rotation + extension + contralateral lateral bending or both combinations of rotation + flexion + ipsilateral lateral bending.
... The entire cervical spine scan was performed with the patient's head in a neutral position, and then upper cervical images were obtained with the head in maximal tolerable rotation, so as to reproduce the conditions of the A-ART in a supine position, using previously described upper cervical imaging protocol [7,8]. 3D Volumetric CT scans were reviewed on a Vitrea (Vital Images) workstation using both 3D and cross-sectional imaging techniques. ...
Post-traumatic rotational instability at the atlanto-axial (C1-2) joint is difficult to assess, much less quantify, due to the orientation and motion plane of the joint. Prior investigations have demonstrated that a dynamic axial CT scan, during which the patient maximally rotates the head right and left, can be used to evaluate and quantify the amount of residual overlap between the inferior articulating facet of C1 and the superior facet of C2, as an index of ligamentous laxity at the joint. We have previously demonstrated that a novel orthopedic test of rotational instability, the atlas-axis rotational test (A-ART), may have utility in identifying patients with imaging evidence of upper cervical ligament injury. In the present investigation, we assessed the correlation between a positive A-ART and a CT scan assessment of the relative quantity of residual C1-2 overlap, as a percent of the superior articulating facet surface area of C2. A retrospective review was conducted of the records of consecutive patients presenting to a physical therapy and rehabilitation clinic, over a 5-year period (2015–20) for chronic head and neck pain after whiplash trauma. The primary inclusion criteria were that the patient had undergone both a clinical evaluation with A-ART and a dynamic axial CT to evaluate for C1-2 residual facet overlap at maximum rotation. The records for a total of 57 patients (44 female/13 male) were identified who fit the selection criteria, and among these, there were 43 with a positive A-ART (i.e., “cases”) and 14 with a negative A-ART (i.e., “controls). The analysis demonstrated that a positive A-ART was highly predictive of decreased residual C1-2 facet overlap: the average overlap area among the cases was approximately one-third that of the control group (on the left, 10.7% versus 29.1%, and 13.6% versus 31.0% on the right). These results suggest that a positive A-ART is a reliable indicator of underlying rotational instability at C1-2 in patients with chronic head and neck symptoms following whiplash trauma.
... Segmental motion contribution represents the percentile contribution of its segment to overall cervical mobility and varies considerably across levels of the cervical spine and performed movements (flexion extension, lateral bending, axial rotation). 11,41,93 The majority of the included studies were based on CT or MRI oftentimes combined with (video)fluoroscopy 29,50,80,88,93 or biplanar radiographs. 3,6,7,9,11,88 Fewer studies were based solely on radiography 27,35,71,75 or fluoroscopy. ...
... This was moderately compensated at the C3-C4 and C4-C5 segments, which contributed 5-10% more AR than non-supine configurations. 37,38,41,91 Both the decreased dynamic loading from the segments' musculature and the different allocation of the head's weight can be associated with this. ...
... Most accounts regarding LB focus on C3-C7 (n = 9, apart from 92 ) and fewer include data about Occ-C3 and C7-Th1 37,38,78,93 (Fig. 2b). AR was commonly reported between C3-C7 (n = 13) while fewer studies referred to Occ-C1, C6-Th1 29,41,91,93 or C1-C3 (Fig. 2c). ...
Knowledge of spinal kinematics is essential for the diagnosis and management of spinal diseases. Distinguishing between physiological and pathological motion patterns can help diagnose these diseases, plan surgical interventions and improve relevant tools and software. During the last decades, numerous studies based on diverse methodologies attempted to elucidate spinal mobility in different planes of motion. The authors aimed to summarize and compare the evidence about cervical spine kinematics under healthy and degenerative conditions. This includes an illustrated description of the spectrum of physiological cervical spine kinematics, followed by a comparable presentation of kinematics of the degenerative cervical spine. Data was obtained through a systematic MEDLINE search including studies on angular/translational segmental motion contribution, range of motion, coupling and center of rotation. As far as the degenerative conditions are concerned, kinematic data regarding disc degeneration and spondylolisthesis were available. Although the majority of the studies identified repeating motion patterns for most motion planes, discrepancies associated with limited sample sizes and different imaging techniques and/or spine configurations, were noted. Among healthy/asymptomatic individuals, flexion extension (FE) and lateral bending (LB) are mainly facilitated by the subaxial cervical spine. C4–C5 and C5–C6 were the major FE contributors in the reported studies, exceeding the motion contribution of sub-adjacent segments. Axial rotation (AR) greatly depends on C1–C2. FE range of motion (ROM) is distributed between the atlantoaxial and subaxial segments, while AR ROM stems mainly from the former and LB ROM from the latter. In coupled motion rotation is quantitatively predominant over translation. Motion migrates caudally from C1–C2 and the center of rotation (COR) translocates anteriorly and superiorly for each successive subaxial segment. In degenerative settings, concurrent or subsequent lesions render the association between diseases and mobility alterations challenging. The affected segments seem to maintain translational and angular motion in early and moderate degeneration. However, the progression of degeneration restrains mobility, which seems to be maintained or compensated by adjacent non-affected segments. While the kinematics of the healthy cervical spine have been addressed by multiple studies, the entire nosological and kinematic spectrum of cervical spine degeneration is partially addressed. Large—scale in vivo studies can complement the existing evidence, cover the gaps and pave the way to technological and clinical breakthroughs.
... The cervical spine is a unique part of the spine because it has canals for important blood vessels and nerves and it allows for movement in 3 orthogonal directions, including rotation. [1][2][3] Like all other bones, the cervical spine undergoes degeneration and decreased bone mineral density (BMD) with aging. 4,5 The risk of fractures of the cervical spine increases because of this diminished BMD. ...
Background
Computed Tomography (CT) scans of the cervical spine are often performed to evaluate patients for trauma and degenerative changes of the cervical spine. We hypothesized that the CT attenuation of the cervical vertebrae can be used to identify patients who should be screened for osteoporosis.
Methods
Retrospective study of 253 patients (177 training/validation and 76 test) with unenhanced CT scans of the cervical spine and DXA studies within 12 months of each other. Volumetric segmentation of C1-T1, clivus, and first ribs was performed to obtain the CT attenuation of each bone. The correlations of the CT attenuations between the bones and with DXA measurements were evaluated. Univariate receiver operator characteristic (ROC) analyses, and multivariate classifiers (Random Forest (RF), XGBoost, Naïve Bayes (NB), and Support Vector Machines (SVM)) analyzing the CT attenuation of all bones, were utilized to predict patients with osteopenia/osteoporosis and femoral neck bone mineral density (BMD) T-scores <-1.
Results
There were positive correlations between the CT attenuation of each bone, and with the DXA measurements. A CT attenuation threshold of 305.2 Hounsfield Units (HU) at C3 had the highest accuracy =0.763 (AUC=0.814) to detect femoral neck BMD T-scores ≤-1 and a CT attenuation threshold of 323.6 HU at C3 had the highest accuracy=0.774 (AUC=0.843) to detect osteopenia/osteoporosis. The SVM classifier (AUC=0.756) had higher AUC than the RF (AUC=0.692, P=0.224), XGBoost (AUC=0.736; P=0.814), NB (AUC=0.622, P=0.133) and CT threshold of 305.2 HU at C3 (AUC=0.704, P=0.531) classifiers to identify patients with femoral neck BMD T-scores <-1. The SVM classifier (accuracy=0.816) was more accurate than using the CT threshold of 305.2 HU at C3 (accuracy=0.671) (McNemar's χ12=7.55, P=0.006).
Conclusion
Opportunistic screening for low BMD can be done using cervical spine CT scans. A SVM classifier was more accurate than using the CT threshold of 305.2 HU at C3.
... 6 The complex nature of the structure and function of the craniocervical junction makes it particularly vulnerable to injury and deformation, as forces acting upon the head and cervical spine may occur in complex patterns. 3 The cervical spine exhibits complicated 3-dimensional movements according to Ref. [7], which could be adequately described using the 3-dimensional CT reconstruction method. Analysis of the reliability of 3-D CT reconstruction method showed very high inter-rater and intra-rater reliability, suggesting very good consistency. ...
... Analysis of the reliability of 3-D CT reconstruction method showed very high inter-rater and intra-rater reliability, suggesting very good consistency. 7 Rotation at the upper cervical spine, specifically the occiput through C2, encompassed at least 60% of the total cervical rotation. Rotation at different parts of the cervical spine in the control group measured 69.7±5.5 for the total rotation of the cervical spine. ...
Objectives
To highlight the detail obtained on a Cone Beam Computed Tomography (CBCT) scan of the craniocervical junction and its usefulness to Chiropractors who specialize in the upper cervical spine. A review of the dose considerations to patients vs radiography in a chiropractic clinical setting and to review the effective radiation dose to the patient.
Methods
A review of studies discussing cervical biomechanics, neurovascular structures, and abnormal radiographic findings, was discussed in relation to chiropractic clinical relevance. Further studies were evaluated demonstrating radiation dose to the patient from radiographs compared to CBCT.
Results
Incidental and abnormal findings of the craniocervical junction were shown to have superior visualization with CBCT compared to radiography. The radiation dose to the patient for similar imaging protocols to the craniocervical junction and cervical spine was equal or less utilizing CBCT when compared to radiographs.
Conclusions
The use of CBCT for visualization of the craniocervical junction and cervical spine in the chiropractic clinical setting allows for adjunctive visualization of the osseous structures which is germane to clinical protocol. Further with CBCT the effective dose to the patient is equal or less than similar imaging protocols utilizing radiographs to evaluate the craniocervical junction.
... First, ΔC1-2 CA was compensated by ΔC2-7 CA as well as ΔO-C1 CA to maintain the horizontal gaze. The preoperative range of motion (ROM) of C1-2 angle in normal people has about 6° when flexion and extension, 23 and compensate for the change of subaxial spine in available ROM. However, postoperative C1-2 angle is fixed after surgery, and it plays the constant no room to change. ...
Objective:
To evaluate which radiologic parameters affect clinical outcomes in patients underwent posterior C1-C2 fusion for atlantoaxial dislocation.
Methods:
From January 2014 to December 2017, among 98 patients underwent C1-C2 posterior fusion, patients with previous cervical surgery or extending to subaxial spine or basilar invagination were excluded. Finally, 38 patients were included. O-C2, C1-2, C1-C7, C2-C7 cobb angle (CA), T1 slope, C1-C7, C2-C7 sagittal vertical axis (SVA), and posterior atlantodental interval (PADI) were measured at preoperative and postoperative one year. The difference between postoperative and preoperative values for each parameter was designated as Δvalue. Postoperative subaxial kyphosis (PSK) was defined to decrease ≥10° at subaxial spine. VAS, JOA score, NDI were used to evaluate clinical outcomes.
Results:
Mean age was 54.4±15.9. Male to female was 14 to 24. Of radiologic parameters, C1-C7 SVA and PADI were significantly changed from 26.4±12.9mm, 17.1±3.3mm to 22.6±13.0mm, 21.6±3.4mm. △C1-C2 CA was correlated with △C1-7 CA and △C2-7 SVA. ΔPADI correlates with ΔO-C2 CA. VAS correlates with △C1-C7 CA (P = 0.03). JOA score also correlates with △C2-C7 SVA (P = 0.02). NDI was associated with ΔPADI (P < 0.01). The incidence of PSK was 23.7%, and not significant with clinical outcomes.
Conclusion:
△C1-C2 CA was correlated with ΔC1-C7 CA, ΔC2-C7 SVA. ΔC1-C7 CA, ΔC2-C7 SVA, and ΔPADI were the key radiologic parameters to influence clinical outcomes. Postoperative C1-C2 angle should be carefully determined as a factor affecting clinical outcomes and cervical sagittal alignment.
