Cervical curvature in acute whiplash injuries: prospective comparative study with asymptomatic subjects

Radiological features of dropped head syndrome

BACKGROUND

This study aimed to elucidate the specificity of the radiological features of Dropped head syndrome (DHS) from both reginal and global aspects.

METHODS

We enrolled 53 patients with DHS (8 men, 45 women; mean age 73.5 years), and captured their lateral spinopelvic radiographs in standing position. We also selected 21 age- and sex-matched controls with cervical spondylosis. Radiological parameters were measured and compared between two groups. Compensatory and decompensatory sites were also listed for each patient.

RESULTS

Radiological factors such as sagittal vertical axis (SVA), clivo-axial angle (CAA), C2-7 angle, C2-7 SVA, anterior slippage of the vertebra, alignment. C1, C2, C3, C4, C5, C6 slopes, and T1 slope-C2-7 angle showed statistically significant differences between the groups. Multivariate logistic regression showed that SVA, C2-7 SVA, T1-slope-C2-7 angle, and C1 slope were the most important factors specific to DHS. Sole cervical spine and involvement of both cervical and thoracic spine accounted for 22% and 29% of the decompensatory sites in DHS respectively. Notably, 24% of the patients did not show decompensation of the cervical spine. While, 93% exhibited compensation at the craniovertebral junction. The thoracic spine contributed 70% to DHS compensation.

CONCLUSIONS

This study indicated the radiological features of DHS from both regional and global aspects. Compensatory and decompensatory DHS mechanisms varied among individuals. Compensation was likely to be developed at the neighboring sites, with the craniovertebral and thoracic junctions as the proximal and distal parts for DHS, respectively.

An investigation into the chiropractic practice and communication of routine, repetitive radiographic imaging for the location of postural misalignments

Many chiropractors use radiological imaging, particularly X-rays, to locate and diagnose the cause of their patients' pain. However, this approach is fundamentally flawed because X-rays provide anatomical information but not functional insights. Pain, tissue damage, and injury do not always correlate directly with X-ray appearances. Given the high incidence of abnormalities found in X-rays of asymptomatic patients, the diagnostic validity of X-rays can be questioned, especially when used in isolation of the patient's history and/or a proper clinical assessment. One may posit that their application promotes overdiagnosis, and unvalidated treatment of X-ray findings (such as changes in postural curvature), which may mislead patients into believing these changes are directly responsible for their pain. A substantial amount of research has shown that there is no association between pain and reversed cervical curves. X-ray accuracy can vary due to several factors, including patient positioning, physical and morphological changes, interreliability among doctors, and other influences such as stress, pain, and emotional state. Over the past two decades, medical boards and health associations worldwide have made significant efforts to communicate better when imaging is necessary, focusing on reducing radiographic imaging. This review describes concerns about the frequent, almost routine use of spinal X-rays in primary care for spine-related pain in the absence of red-flag clinical signs.

An investigation into the chiropractic practice and communication of routine repetitive radiographic imaging for the location of postural misalignments

Many clinicians use radiological imaging in efforts to locate and diagnose the cause of their patient's pain, relying on X-rays as a leading tool in clinical evaluation. This is fundamentally flawed because an X-ray represents a "snapshot" of the structural appearance of the spine and gives no indication of the current function of the spine. The health and well-being of any system, including the spinal motion segments, depend on the inter-relationship between structure and function. Pain, tissue damage, and injury are not always directly correlated. Due to such a high incidence of abnormalities found in asymptomatic patients, the diagnostic validity of X-rays can be questioned, especially when used in isolation of history and/or proper clinical assessment. The utility of routine X-rays is, therefore, questionable. One may posit that their application promotes overdiagnosis, and unvalidated treatment of X-ray findings (such as changes in postural curvature), which may mislead patients into believing these changes are directly responsible for their pain. A substantial amount of research has shown that there is no association between pain and reversed cervical curves. Accuracy can also be questioned, as X-ray measurements can vary based on the patient's standing position, which research shows is influenced by an overwhelming number of factors, such as patient positioning, patient physical and morphological changes over time, doctor interreliability, stress, pain, the patient's previous night's sleep or physical activity, hydration, and/or emotional state. Furthermore, research has concluded that strong evidence links various potential harms with routine, repeated X-rays, such as altered treatment procedures, overdiagnosis, radiation exposure, and unnecessary costs. Over the past two decades, medical boards and health associations worldwide have made a substantial effort to communicate better "when" imaging is required, with most education around reducing radiographic imaging. In this review, we describe concerns relating to the high-frequency, routine use of spinal X-rays in the primary care setting for spine-related pain in the absence of red-flag clinical signs.

Abnormal Static Sagittal Cervical Curvatures following Motor Vehicle Collisions: A Retrospective Case Series of 41 Patients before and after a Crash Exposure

Previous investigations have found a correlation between abnormal curvatures and a variety of patient complaints such as cervical pain and disability. However, no study has shown that loss of the cervical curve is a direct result of exposure to a motor vehicle collision (MVC). This investigation presents a retrospective consecutive case series of patients with both a pre-injury cervical lateral radiograph (CLR) and a post-injury CLR after exposure to an MVC. Computer analysis of digitized vertebral body corners on CLRs was performed to investigate the possible alterations in the geometric alignment of the sagittal cervical curve.

METHODS

Three spine clinic records were reviewed over a 2-year period, looking for patients where both an initial lateral cervical X-ray and an examination were performed prior to the patient being exposed to a MVC; afterwards, an additional exam and radiographic analysis were obtained. A total of 41 patients met the inclusion criteria. Examination records of pain intensity on numerical pain rating scores (NPRS) and neck disability index (NDI), if available, were analyzed. The CLRs were digitized and modeled in the sagittal plane using curve fitting and the least squares error approach. Radiographic variables included total cervical curve (ARA C2-C7), Chamberlain's line to horizontal (skull flexion), horizontal translation of C2 relative to C7, segmental translations (retrolisthesis and anterolisthesis), and circular modelling radii.

RESULTS

There were 15 males and 26 females with an age range of 8-65 years. Most participants were drivers (28) involved in rear-end impacts (30). The pre-injury NPRS was 2.7 while the post injury was 5.0; p < 0.001. The NDI was available on 24/41 (58.5%) patients and increased after the MVC from 15.7% to 32.8%, p < 0.001. An altered cervical curvature was identified following exposure to MVC, characterized by an increase in the mean radius of curvature (265.5 vs. 555.5, p < 0.001) and an approximate 8° reduction of lordosis from C2-C7; p < 0.001. The mid-cervical spine (C3-C5) showed the greatest curve reduction with an averaged localized mild kyphosis at these levels. Four participants (10%) developed segmental translations that were just below the threshold of instability, segmental translations < 3.5 mm.

CONCLUSIONS

The post-exposure MVC cervical curvature was characterized by an increase in radius of curvature, an approximate 8° reduction in C2-C7 lordosis, a mild kyphosis of the mid-cervical spine, and a slight increase in anterior translation of C2-C7 sagittal balance. The modelling result indicates that the post-MVC cervical sagittal alignment approximates a second-order buckling alignment, indicating a significant alteration in curve geometry. Future biomechanics experiments and clinical investigations are needed to confirm these findings.

Adult cervical spine deformity: a state-of-the-art review

Adult cervical deformity is a structural malalignment of the cervical spine that may present with variety of significant symptomatology for patients. There are clear and substantial negative impacts of cervical spine deformity, including the increased burden of pain, limited mobility and functionality, and interference with patients' ability to work and perform everyday tasks. Primary cervical deformities develop as the result of a multitude of different etiologies, changing the normal mechanics and structure of the cervical region. In particular, degeneration of the cervical spine, inflammatory arthritides and neuromuscular changes are significant players in the development of disease. Additionally, cervical deformities, sometimes iatrogenically, may present secondary to malalignment or correction of the thoracic, lumbar or sacropelvic spine. Previously, classification systems were developed to help quantify disease burden and influence management of thoracic and lumbar spine deformities. Following up on these works and based on the relationship between the cervical and distal spine, Ames-ISSG developed a framework for a standardized tool for characterizing and quantifying cervical spine deformities. When surgical intervention is required to correct a cervical deformity, there are advantages and disadvantages to both anterior and posterior approaches. A stepwise approach may minimize the drawbacks of either an anterior or posterior approach alone, and patients should have a surgical plan tailored specifically to their cervical deformity based upon symptomatic and radiographic indications. This state-of-the-art review is based upon a comprehensive overview of literature seeking to highlight the normal cervical spine, etiologies of cervical deformity, current classification systems, and key surgical techniques.

Prevalence and risk factors of occupational neck pain in Chinese male fighter pilots: a cross-sectional study based on questionnaire and cervical sagittal alignment

Background

Neck pain (NP) is a common musculoskeletal disorder among fighter pilots and has become a rising concern due to its detrimental impact on military combat effectiveness. The occurrence of NP is influenced by a variety of factors, but less attention has been paid to the association of NP with demographic, occupational, and cervical sagittal characteristics in this group. This study aimed to investigate the prevalence and risk factors of NP in Chinese male fighter pilots using a questionnaire and cervical sagittal measurements.

Methods

Demographic and flight-related data, as well as musculoskeletal pain information, were gathered from Chinese male fighter pilots via a self-report questionnaire. Cervical sagittal parameters were measured and subtypes were classified using standardized lateral cervical radiographs. Differences in various factors between the case and control groups were analyzed using t-tests or chi-square tests. Binary logistic regressions were conducted to explore potential risk factors contributing to NP. Predictors were presented as crude odds ratios (CORs) and adjusted odds ratios (AORs), along with their respective 95% confidence intervals (CIs).

Results

A total of 185 male fighter pilots were included in this cross-sectional study. Among them, 96 (51.9%) reported experiencing NP within the previous 12 months. The multivariate regression analysis revealed that continuous flight training (AOR: 4.695, 95% CI: 2.226-9.901, p < 0.001), shoulder pain (AOR: 11.891, 95% CI: 4.671-30.268, p < 0.001), and low back pain (AOR: 3.452, 95% CI: 1.600-7.446, p = 0.002) were significantly associated with NP.

Conclusion

The high 12-month prevalence of NP among Chinese male fighter pilots confirms the existence of this growing problem. Continuous flight training, shoulder pain, and low back pain have significant negative effects on pilots' neck health. Effective strategies are necessary to establish appropriate training schedules to reduce NP, and a more holistic perspective on musculoskeletal protection is needed. Given that spinal integrated balance and compensatory mechanisms may maintain individuals in a subclinical state, predicting the incidence of NP in fighter pilots based solely on sagittal characteristics in the cervical region may be inadequate.

Clinical and Radiological Characteristics of Cervical Spondylotic Myelopathy in Young Adults: A Retrospective Case Series of Patients under Age 30

Background and Objectives: Cervical spondylotic myelopathy (CSM) is a degenerative disease and occurs more frequently with age. In fact, the development of non-herniated CSM under age 30 is uncommon. Therefore, a retrospective case series was designed to clarify clinical and radiological characteristics of young adult patients with CSM under age 30. Materials and Methods: A total of seven patients, all men, with non-herniated, degenerative CSM under age 30 were retrieved from the medical records of 2598 hospitalized CSM patients (0.27%). Patient demographics and backgrounds were assessed. The sagittal alignment, congenital canal stenosis, dynamic canal stenosis, and vertebral slips in the cervical spine were radiographically evaluated. The presence of degenerative discs, intramedullary high-signal intensity lesions, and sagittal spinal cord compression on T2-weighted magnetic resonance images (MRIs) and axial spinal cord deformity on T1-weighted MRIs was identified. Results: All patients (100.0%) had relatively high daily sports activities and/or jobs requiring frequent neck extension. Cervical spine radiographs revealed the sagittal alignment as the “reverse-sigmoid” type in 57.1% of patients and “straight” type in 28.6%. All patients (100.0%) presented congenital cervical stenosis with the canal diameter ≤12 mm and/or Torg–Pavlov ratio <0.80. Furthermore, all patients (100.0%) developed dynamic stenosis with the canal diameter ≤12 mm and/or posterior vertebral slip ≥2 mm at the neurologically responsible segment in full-extension position. In MRI examination, all discs at the neurologically responsible level (100.0%) were degenerative. Intramedullary abnormal intensity lesions were detected in 85.7% of patients, which were all at the neurologically responsible disc level. Conclusions: Patients with non-herniated, degenerative CSM under age 30 are rare but more common in men with mild sagittal “reverse-sigmoid” or “straight” deformity and congenital canal stenosis. Relatively high daily activities, accumulating neck stress, can cause an early development of intervertebral disc degeneration and dynamic canal stenosis, leading to CSM in young adults.

Non-Surgical Management of Upper Cervical Instability via Improved Cervical Lordosis: A Case Series of Adult Patients

Injury to the head and neck resulting from whiplash trauma can result in upper cervical instability (UCIS), in which excessive movement at C1 on C2 is observed radiologically. In some cases of UCIS there is also a loss of normal cervical lordosis. We postulate that improvement or restoration of the normal mid to lower cervical lordosis in patients with UCIS can improve the biomechanical function of the upper cervical spine, and thus potentially improve symptoms and radiographic findings associated with UCIS. Nine patients with both radiographically confirmed UCIS and loss of cervical lordosis underwent a chiropractic treatment regimen directed primarily at the restoration of the normal cervical lordotic curve. In all nine cases, significant improvements in radiographic indicators of both cervical lordosis and UCIS were observed, along with symptomatic and functional improvement. Statistical analysis of the radiographic data revealed a significant correlation (R² = 0.46, p = 0.04) between improved cervical lordosis and reduction in measurable instability, determined by C1 lateral mass overhang on C2 with lateral flexion. These observations suggest that enhancing cervical lordosis can contribute to improvement in signs and symptoms of upper cervical instability secondary to traumatic injury.

The Effect of Seat Back Inclination on Spinal Alignment in Automotive Seating Postures

Experimental studies have demonstrated a relationship between spinal injury severity and vertebral kinematics, influenced by the initial spinal alignment of automotive occupants. Spinal alignment has been considered one of the possible causes of gender differences in the risk of sustaining spinal injuries. To predict vertebral kinematics and investigate spinal injury mechanisms, including gender-related mechanisms, under different seat back inclinations, it is needed to investigate the effect of the seat back inclination on initial spinal alignment in automotive seating postures for both men and women. The purpose of this study was to investigate the effect of the seat back inclination on spinal alignments, comparing spinal alignments of automotive seating postures in the 20° and 25° seat back angle and standing and supine postures. The spinal columns of 11 female and 12 male volunteers in automotive seating, standing, and supine postures were scanned in an upright open magnetic resonance imaging system. Patterns of their spinal alignments were analyzed using Multidimensional Scaling presented in a distribution map. Spinal segmental angles (cervical curvature, T1 slope, total thoracic kyphosis, upper thoracic kyphosis, lower thoracic kyphosis, lumbar lordosis, and sacral slope) were also measured using the imaging data. In the maximum individual variances in spinal alignment, a relationship between the cervical and thoracic spinal alignment was found in multidimensional scaling analyses. Subjects with a more lordotic cervical spine had a pronounced kyphotic thoracic spine, whereas subjects with a straighter to kyphotic cervical spine had a less kyphotic thoracic spine. When categorizing spinal alignments into two groups based on the spinal segmental angle of cervical curvature, spinal alignments with a lordotic cervical spine showed significantly greater absolute average values of T1 slope, total thoracic kyphosis, and lower thoracic kyphosis for both the 20° and 25° seat back angles. For automotive seating postures, the gender difference in spinal alignment was almost straight cervical and less-kyphotic thoracic spine for the female subjects and lordotic cervical and more pronounced kyphotic thoracic spine for the male subjects. The most prominent influence of seatback inclination appeared in Total thoracic kyphosis, with increased angles for 25° seat back, 8.0° greater in spinal alignments with a lordotic cervical spine, 3.2° greater in spinal alignments with a kyphotic cervical spine. The difference in total thoracic kyphosis between the two seatback angles and between the seating posture with the 20° seat back angle and the standing posture was greater for spinal alignments with a lordotic cervical spine than for spinal alignments with a kyphotic cervical spine. The female subjects in this study had a tendency toward the kyphotic cervical spine. Some of the differences between average gender-specific spinal alignments may be explained by the findings observed in the differences between spinal alignments with a lordotic and kyphotic cervical spine.

The Lack of Sex, Age, and Anthropometric Diversity in Neck Biomechanical Data

Female, elderly, and obese individuals are at greater risk than male, young, and non-obese individuals for neck injury in otherwise equivalent automotive collisions. The development of effective safety technologies to protect all occupants requires high quality data from a range of biomechanical test subjects representative of the population at risk. Here we sought to quantify the demographic characteristics of the volunteers and post-mortem human subjects (PMHSs) used to create the available biomechanical data for the human neck during automotive impacts. A systematic literature and database search was conducted to identify kinematic data that could be used to characterize the neck response to inertial loading or direct head/body impacts. We compiled the sex, age, height, weight, and body mass index (BMI) for 999 volunteers and 110 PMHSs exposed to 5,431 impacts extracted from 63 published studies and three databases, and then compared the distributions of these parameters to reference data drawn from the neck-injured, fatally-injured, and general populations. We found that the neck biomechanical data were biased toward males, the volunteer data were younger, and the PMHS data were older than the reference populations. Other smaller biases were also noted, particularly within female distributions, in the height, weight, and BMI distributions relative to the neck-injured populations. It is vital to increase the diversity of volunteer and cadaveric test subjects in future studies in order to fill the gaps in the current neck biomechanical data. This increased diversity will provide critical data to address existing inequities in automotive and other safety technologies.

The Long-term Impact of Whiplash Injuries on Patient Symptoms and the Associated Degenerative Changes Detected Using MRI: A Prospective 20-year Follow-up Study Comparing Patients with Whiplash-associated Disorders with Asymptomatic Subjects

STUDY DESIGN

A longitudinal, 20-year comparative study of patients with whiplash-associated disorders (WAD).

OBJECTIVE

The aim of this study was to clarify the long-term impact of WAD on patient symptoms and on magnetic resonance imaging (MRI) findings of the cervical spine, in comparison with asymptomatic volunteers.

SUMMARY OF BACKGROUND DATA

The long-term impact of WAD has not been fully elucidated.

METHODS

Between 1993 and 1996, we conducted a cross-sectional comparative study of 508 acute WAD patients and 497 asymptomatic volunteers, all of whom underwent MRI on cervical spine and physical examinations. For this 20-year follow-up comparative study, 75 WAD patients and 181 control subjects aged <60 years were recruited from the original cohort. The MRI findings, including discs' signal intensities, posterior disc protrusions, anterior dural compressions, spinal cord disc space narrowing, and foraminal stenoses, were evaluated using two to four numerical grades. The results of the WAD patients and control subjects were compared.

RESULTS

In this follow-up, the prevalence of shoulder stiffness (72.0% vs. 45.9%), headache (24.0% vs. 12.2%), and arm pain (13.3% vs. 3.9%) were significantly greater in WAD patients than in control subjects. The multiregression analysis revealed that a history of WAD was associated with shoulder stiffness (odds ratio [OR]: 3.36), headache (OR: 2.39), and arm pain (OR: 3.82). Although MRI findings in WAD patients were more degenerated than in control subjects in the initial study, all MRI findings were similar at the 20-year follow-up. There were no significant correlations between clinical cervical symptoms and progression in each MR finding in either group.

CONCLUSION

After 20 years, whiplash injuries significantly impacted the residual symptoms of shoulder stiffness, headache, and arm pain when compared with initially asymptomatic volunteers. The progression of degenerative changes in the cervical intervertebral discs after 20 years revealed no association with existing whiplash injuries, neither did the residual cervical-related symptoms.Level of Evidence: 3.

Clinical and radiological outcomes of kinesiotaping in patients with chronic neck pain: A double-blinded, randomized, placebo-controlled study

Objectives

In this study, we aimed to evaluate the efficacy of kinesiotaping (KT) in patients with chronic non-specific neck pain (NSNP) in terms of pain, disability, cervical range of motion (ROM), and cervical lordosis.

Patients and methods

Between October 2013 and March 2014, a total of 50 patients (10 males, 40 females; mean age 35.1±9.9 years; range, 17 to 62 years) with chronic NSNP were randomized into the KT (n=25) or the sham KT intervention (n=25) groups. Both groups were additionally given a therapeutic exercise (TE) program. The Visual Analog Scale (VAS) and Neck Disability Index (NDI) scores and ROM measurements were recorded at baseline, at the end of treatment, and at one month. Lateral cervical digital radiographs were analyzed by the Cobb, posterior tangent and effective lordosis methods at baseline and at one month after the treatment.

Results

There was a statistically significant decrease in the VAS scores compared to baseline in the KT group. The NDI scores significantly decreased in both groups. The patients in the KT group experienced a significant increase in all planes of cervical ROM after the treatment. Cervical radiographs revealed a significant increase in the Cobb and posterior tangent angles only in the KT group.

Conclusion

Our study results suggest that KT significantly improves VAS, NDI scores, ROM and cervical lordosis angles. The combination of TE and KT is useful in reducing pain and disability and improving ROM and cervical lordosis loss in patients with chronic NSNP.

Sagittal alignment of the cervical spine: do we know enough for successful surgery?

Over the past decade, there has been growing interest in the sagittal alignment of the cervical spine and its correlation to clinical outcomes. It is now known that cervical lordosis is not universally physiological and should not be pursued in all patients undergoing surgery. Rather, it is increasingly understood that it is how these angular parameters (lordosis or kyphosis) interact with translational parameters that is reflective of overall cervical spine and whole spine balance, which in turn impacts patient outcomes. This review synthesises currently available evidence relating to the sagittal alignment of the cervical spine. Radiographic assessment of the cervical spine including horizontal gaze is discussed and alignment in physiological and pathological states analysed. The interdependence of spinal segments is reviewed, with cervical alignment correction influencing the adjacent thoracic spine, and similarly lumbar lordosis (LL) and global balance correction changing cervical spine alignment. Cervical kyphosis with associated cervical sagittal imbalance is known to lead to poorer post-operative outcomes, and this dichotomy in outcomes has not been shown to improve even with alignment correction. Further work is required to uncover the extent to which cervical spine alignment correction should be attempted toward improved patient outcomes, in order to plan and deliver patient-specific surgical realignment targets.

Relationship Between Cervical, Thoracic and Lumbar Spinal Alignments in Automotive Seated Posture

The purpose of this study was to investigate the relationship between cervical, thoracic and lumbar spinal alignments in one automotive occupant seated posture. An image data set of the spinal column in the automotive seated posture, previously acquired by an upright open Magnetic Resonance Imaging system, were reanalysed in this study. Spinal alignments were presented by the geometrical centres of the vertebral bodies extracted from the image data. Cervical, thoracic and lumbar spinal alignments were analysed separately with Multi-Dimensional Scaling (MDS). Based on distribution maps of cervical, thoracic and lumbar spinal alignments created by MDS, representative spinal alignment patterns of the cervical, thoracic and lumbar spines and the relationship between cervical, thoracic and lumbar spinal alignments were investigated. As a result, this study found a correlation between cervical and thoracic spinal alignments in an automotive occupant seated posture. According to representative spinal alignment patterns illustrated by the distribution map of spinal alignments, subjects who had kyphotic cervical spinal alignment tended to have less kyphotic thoracic spinal alignment, while subjects who had lordotic cervical spinal alignment tended to have more kyphotic thoracic spinal alignment. For lumbar spinal alignments, no prominent relationship was found between cervical or thoracic spinal alignment in the seated condition of this study.

Cervical lordosis in asymptomatic individuals: a meta-analysis

Background

Cervical lordosis has important clinical and surgical implications. Cervical spine curvature is reported with considerable variability in individual studies. The aim of this study was to examine the existence and extent of cervical lordosis in asymptomatic individuals and to evaluate its relationship with age and gender.

Methods

A comprehensive literature search was conducted in several electronic databases. Study selection was based on pre-determined eligibility criteria. Random effects meta-analyses were performed to estimate the proportion of asymptomatic individuals with lordosis and the effect size of cervical lordotic curvature in these individuals which followed metaregression analysis to examine the factors affecting cervical lordosis. Data from 21 studies (15,364 asymptomatic individuals, age 42.30 years [95% confidence interval 36.42, 48.18], 54.2% males) were used in the present study.

Results

In this population, 63.99% [95% confidence interval 44.94, 83.03] individuals possessed lordotic curvature. Degree of lordotic curvature differed by method of measurement; 12.71° [6.59, 18.84] with Cobb C2–C7 method and 18.55° [14.48, 22.63] with posterior tangent method. Lordotic curvature was not significantly different between symptomatic and asymptomatic individuals but was significantly higher in males in comparison with females. Age was not significantly associated with lordotic cervical curvature.

Conclusion

Majority of the asymptomatic individuals possesses lordotic cervical curvature which is higher in males than in females but have no relationship with age or symptoms.

Influence of morphological variations on cervical spine segmental responses from inertial loading

OBJECTIVES

The objective of this study was to investigate the influence of morphological variations in osteoligamentous lower cervical spinal segment responses under postero-anterior inertial loading.

METHODS

A parametric finite element model of the C5-C6 spinal segment was used to generate models. Variations in the vertebral body and facet depth (anteroposterior), posterior process length, intervertebral disc height, facet articular process height and slope, segment orientation ranging from lordotic to straight, and segment size were parameterized. These variations included male-female differences. A Latin hypercube sampling method was used to select parameter values for model generation. Forces and moments associated with the inertial loading were applied to the generated model segments. The 7 parameters were grouped as local or global depending on the number of spinal components involved in the shape variation. Four output responses representing overall segmental and soft tissue responses were analyzed for each model variation: response angle of the segment, anterior longitudinal ligament stretch, anterior capsular ligament stretch, and facet joint compression in the posterior region. Pearson's correlation coefficient was used to compute the correlations of these output responses with morphological variations.

RESULTS

Fifty models were generated from the parameterized model using a Latin hypercube sampling technique. Variation in response angle among the models was 4° and was most influenced by change in the combined dimension of vertebral body and facet depth, followed by size of the segment. The maximum anterior longitudinal ligament stretch varied between 0.1 and 0.3 and was strongly influenced by the change in the segment orientation. The anterior facet joint region sustained tension, whereas the posterior region sustained compression. For the anterior capsular ligament stretch, the most influential global variation was segment orientation, whereas the most influential local variations were the facet height and facet angle parameters. In the case of posterior facet joint compression, segment orientation was again most influential, whereas among the local variations, the facet angle had the most influence.

CONCLUSION

Shape variations in the intervertebral disc influenced segmental rotation and ligament responses; however, the influence of shape variations in the facet joint was confined to capsular ligament responses. Response angle was most influenced by the vertebral body depth variations, explaining greater segmental rotations in female spines. Straighter spine segments sustained greater posterior facet joint compression, which may offer an explanation for the higher incidence of whiplash-associated disorders among females, who exhibit a straighter cervical spine. The anterior longitudinal ligament stretch was also greater in straighter segments. These findings indicate that the morphological features specific to the anatomy of the female cervical spine may predispose it to injury under inertial loading.

Reproducibility of sagittal radiographic parameters in adolescent idiopathic scoliosis-a guide to reference values using serial imaging

BACKGROUND CONTEXT

Knowledge of sagittal radiographic parameters in adolescent idiopathic scoliosis (AIS) patients has not yet caught up with our understanding of their roles in patients with adult spinal deformity. It is likely that more emphasis will be placed in restoring sagittal parameters for AIS patients in the future. Therefore, we need to understand how these parameters may vary in AIS to facilitate management plans.

PURPOSE

This study aimed to determine the reproducibility of sagittal spinal parameters on lateral film radiographs in patients with AIS.

STUDY DESIGN/SETTING

This was a retrospective, comparative study conducted in a tertiary health-care institution from January 2013 to February 2016 (3-year period).

PATIENT SAMPLE

All AIS patients who underwent deformity correction surgery from January 2013 to February 2016 and had two preoperative serial lateral radiographs taken within the time period of a month were included in the study.

OUTCOME MEASURES

Radiographic sagittal spinal parameters including sagittal vertical axis (SVA), cervical lordosis (CL), thoracic kyphosis (TK), thoracolumbar alignment (TL), lumbar lordosis (LL); standard spinopelvic measurements such as pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS); as well as end and apical vertebrae of cervical, thoracic, and lumbar curves were the outcome measures.

METHODS

All patient data were pooled from electronic medical records, and X-ray images were retrieved from Centricity Enterprise Web. Averaged X-ray measurements by two independent assessors were analyzed by comparing two radiographs of the same patients performed within a 1-month time period. Chi-squared and Wilcoxon signed-rank tests were used for categorical and continuous variables.

RESULTS

The study cohort comprised 138 patients, 28 men and 110 women, with a mean age of 15 years (range 11-20). Between the two lateral X-rays, there was a mean difference of 0.79 cm in SVA (p<.001), 0.70° in LL (p=.033), and 0.73° in PT (p=.010). In the combined Lenke 1 and 2 subgroup, there was a similar 0.77 cm (p=.002), 0.79° (p=.009), and 1.49° (p=.001) mean difference in SVA, LL, and PT, respectively. Additionally, there was also a 1.85° (p=.009) and 1.76° (p=.006) mean difference seen in TL and SS, respectively. The overall profile of the sagittal curves remained largely similar, with only the lumbar apex shifting from L3 to L4 during the first and the second X-rays, respectively (p<.001). This occurred for the combined Lenke 1 and 2 subgroup as well (p<.001).

CONCLUSION

Most radiographic sagittal spinal parameters in AIS patients are generally reproducible with some variations up to a maximum of 4°. This natural variation should be taken into account when interpreting these radiographic sagittal parameters so as to achieve the most accurate results in surgical planning.

Effects of whole spine alignment patterns on neck responses in rear end impact

OBJECTIVE

The aim of this study was to investigate the whole spine alignment in automotive seated postures for both genders and the effects of the spinal alignment patterns on cervical vertebral motion in rear impact using a human finite element (FE) model.

METHODS

Image data for 8 female and 7 male subjects in a seated posture acquired by an upright open magnetic resonance imaging (MRI) system were utilized. Spinal alignment was determined from the centers of the vertebrae and average spinal alignment patterns for both genders were estimated by multidimensional scaling (MDS). An occupant FE model of female average size (162 cm, 62 kg; the AF 50 size model) was developed by scaling THUMS AF 05. The average spinal alignment pattern for females was implemented in the model, and model validation was made with respect to female volunteer sled test data from rear end impacts. Thereafter, the average spinal alignment pattern for males and representative spinal alignments for all subjects were implemented in the validated female model, and additional FE simulations of the sled test were conducted to investigate effects of spinal alignment patterns on cervical vertebral motion.

RESULTS

The estimated average spinal alignment pattern was slight kyphotic, or almost straight cervical and less-kyphotic thoracic spine for the females and lordotic cervical and more pronounced kyphotic thoracic spine for the males. The AF 50 size model with the female average spinal alignment exhibited spine straightening from upper thoracic vertebra level and showed larger intervertebral angular displacements in the cervical spine than the one with the male average spinal alignment.

CONCLUSIONS

The cervical spine alignment is continuous with the thoracic spine, and a trend of the relationship between cervical spine and thoracic spinal alignment was shown in this study. Simulation results suggested that variations in thoracic spinal alignment had a potential impact on cervical spine motion as well as cervical spinal alignment in rear end impact condition.

Loss of cervical lordosis: What is the prognosis?

Neck pain is a diffuse problem with a high incidence and often leads to the more or less appropriate prescription of imaging studies of the cervical spine. In general, this is represented by a magnetic resonance imaging (MRI) scan. Frequently such studies reveal no other significant findings apart from a loss of cervical lordosis either under the form of a simple straightening of the spine or even an inversion of the normal curvature into a kyphosis. Faced with this entity, the clinician is put in front of a series of questions: to which extent such a finding plays a role in the patient's symptoms? If it does what is the role of conservative or even invasive treatment? What are the implications for surgery either for decompressive procedures or corrective procedures? To shed some light on these questions, the authors present a narrative review of the most relevant literature on the topic. Papers examined span from the initial epidemiologic reports out of the pre-MRI and computerized tomography era up to the most recent discussions on cervical sagittal alignment and its implications both for the surgical and nonsurgical patient. In this process, it becomes increasingly clear that we are still far from making any definite statements.

The Effect of Different Pillow Heights on the Parameters of Cervicothoracic Spine Segments

Objective

To investigate the effect of different pillow heights on the slope of the cervicothoracic spine segments.

Methods

A prospective analysis of data from 16 asymptomatic adults (aged 20 to 30 years) was carried out. Exclusion criteria were history of injury or accident to the cervicothoracic spine, cervicothoracic spine surgery, or treatment for neck symptoms. We used three different pillow heights: flat (0 cm), 10-cm, and 20-cm pillows. Cervical sagittal parameters, measured with radiography, included; C2-7 Cobb's angle, T1 slope (T1S), thoracic inlet angle (TIA), and neck tilt (NT). Statistical analyses were performed using Spearman correlation coefficients.

Results

As the height of the pillow increased, the T1S & C2-7 Cobb's angle increased while the NT values tended to decrease. The TIA values, however, remained constant. Additionally, there was a statistically significant sex difference in T1S with the 0-cm pillow (p=0.01), and in NT with the 20-cm pillow (p=0.01).

Conclusion

From the data obtained in this study, we recommend that the most suitable pillow height is 10 cm, considering the normal cervical lordosis.

Factors determining cervical spine sagittal balance in asymptomatic adults: correlation with spinopelvic balance and thoracic inlet alignment

BACKGROUND CONTEXT

Based on the previous studies, cervical lordosis (CL) is a parameter influenced by thoracic kyphosis (TK); however, the correlations still remain unclear. Few studies have analyzed the correlations between the cervical spine lordosis and global spinopelvic balance. To date, there has been no study focused on the factors determining cervical spine sagittal balance.

PATIENT SAMPLE

Seventy-seven asymptomatic volunteers without the history of symptoms related to whole spine.

OUTCOME MEASURES

Statistical significance of correlations of radiographic parameters on cervical spine and whole-spine standing lateral radiograph.

PURPOSE

To analyze the factors determining cervical spine sagittal balance, including global spinopelvic balance and thoracic inlet (TI) alignment in asymptomatic adults.

STUDY DESIGN

A prospective radiographic study.

METHODS

Cervical and whole-spine standing lateral radiographs were taken to analyze the following parameters: spinopelvic parameters pelvic incidence (PI), sacral slope (SS), lumbar lordosis (LL), and TK; TI parameters thoracic inlet angle (TIA) and T1 slope; and cervical spine parameters C0-C2, C2-C7, and C0-C7 angles and cervical tilting. Statistical analysis was performed using the Pearson correlation coefficients and multiple regression analysis.

RESULTS

All the parameters showed a normal distribution. There was a significant sequential linkage between PI and SS (r=0.653), SS and LL (r=0.807), LL and TK (r=-0.516), and TK and C0-C7 angle (r=-0.322). There was a significant relationship between TK and T1 slope (r=0.351) but no significant relationship between TK and TIA. There were significant sequential relationships between TIA and T1 slope (r=0.694), T1 slope and C2-C7 angle (r=-0.624), and C2-C7 and C0-C2 angles (r=-0.547). T1 slope was the only parameter that demonstrated a significant correlation with both SP and TI parameters. A linear regression model showed that T1 slope had a stronger relationship with TIA (r=0.694) than TK (r=0.351).

CONCLUSIONS

T1 slope was a key factor determining cervical spine sagittal balance. Both spinopelvic balance and TI alignment have a significant influence on cervical spine sagittal balance via T1 slope, but TIA had a stronger effect than TK. An individual with large T1 slope required large CL to preserve physiologic sagittal balance of the cervical spine. The results of the present study could serve as baseline data for further studies on the cervical spine sagittal balance in various clinical conditions including the surgical reconstruction of lordosis.

An investigation of cervical spinal posture in cervicogenic headache

BACKGROUND

Cervicogenic headache (CGH) is defined as headache symptoms originating from the cervical spine. Cervical dysfunction from abnormal posture has been proposed to aggravate or cause CGH, but there are conflicting reports as to whether there is an association between posture and CGH.

OBJECTIVE

The purpose of this study was to evaluate differences in cervical spinal posture, measured on radiographs, between patients with probable CGH and asymptomatic control participants.

DESIGN

A single-blinded comparative measurement design was used.

METHODS

Differences in postural variables from radiographs between participants with CGH (n=30) and age- and sex-matched asymptomatic control participants (n=30) were determined using paired t tests or the nonparametric equivalent. Postural variables were general cervical lordosis (GCL, Cobb angle C2-C7), upper cervical lordosis (UCL, sagittal alignment C2 compared with C3-C4), and C2 spinous process horizontal deviation. Logistic regression determined postural variables, increasing the likelihood of CGH.

RESULTS

There were no significant differences in posture between the CGH and control groups. The mean GCL was 10.97 degrees (SD=7.50) for the CGH group and 7.17 degrees (SD=5.69) for the control group. The mean UCL was 11.86 degrees (SD=6.46) for the CGH group and 9.44 degrees (SD=4.28) for the control group. The mean C2 spinous process horizontal deviation was 3.00 mm (SD=1.66) for the CGH group and 2.86 mm (SD=2.04) for the control group. However, there was a significant association between greater GCL and an increased likelihood of having CGH (odds ratio=1.08; 95% confidence interval=1.001, 1.191).

LIMITATIONS

The findings are limited to an association between GCL and posture, as cause and effect cannot be determined.

CONCLUSIONS

The association between greater GCL and increased likelihood of having CGH suggests that GCL might be considered in the treatment of patients with CGH. However, as the data do not support posture as a cause of CGH, it is unknown whether addressing posture would reduce CGH.

Modified K-line in magnetic resonance imaging predicts clinical outcome in patients with nonlordotic alignment after laminoplasty for cervical spondylotic myelopathy

STUDY DESIGN

Retrospective single-center study.

OBJECTIVE

To investigate whether a preoperative index predicts clinical outcome after laminoplasty for cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

This is the first study using the modified K-line, which connects the midpoints of the spinal cord at the C2 and C7 levels on midsagittal magnetic resonance imaging, to assess the relationship between postoperative clinical outcome and anticipated degree of spinal cord shifting.

METHODS

Sixty-one consecutive patients who underwent laminoplasty for the treatment of cervical spondylotic myelopathy between 2000 and 2011 at our hospital were retrospectively reviewed. The interval between the preoperative mK-line and the anterior structure of the spinal canal at each segment of the C3 to C6 levels (INTn, n = 3-6) were measured on sagittal T1-weighted magnetic resonance imaging, and the sum of the INTn (INTsum) was then calculated. The degree of posterior cord shift was defined as follows: %Csum = ΣCn; Cn = (Bn-An) × 100/An (n = 3-6; An and Bn represent the preoperative and postoperative intervals between the midpoint of the spinal cord and the anterior impingement at each segment on sagittal T1-weighted magnetic resonance imaging, respectively). In addition, we defined INTmin as the minimum interval of the INTn in each patient. All patients were divided into lordotic and nonlordotic groups on the basis of lateral neutral radiography. The Japanese Orthopaedic Association (JOA) scoring system and recovery rate of the JOA score for cervical myelopathy was evaluated as clinical outcomes.

RESULTS

The recovery rate of the JOA score was 48.1%. The lordotic and nonlordotic groups contained 38 and 23 patients, respectively. Linear regression analysis revealed that INTmin was significantly correlated with the recovery rate of the patients in the nonlordotic group, whereas INTsum was not associated with recovery of the JOA score.

CONCLUSION

We identified INTmin as a predictive factor for clinical outcomes in patients with nonlordotic alignment after laminoplasty.

LEVEL OF EVIDENCE

4.

Identifying and treating the causes of neck pain

Future studies are needed to further understand the pathophysiology of mechanical neck pain. Robust scientific evidence is sparse on which noninvasive treatments are the most beneficial and how to better select patients for particular noninvasive or invasive treatments.

Modic changes of the cervical spine in patients with whiplash injury: a prospective 11-year follow-up study

INTRODUCTION

There are few studies on Modic changes of the cervical spine in patients suffering from whiplash. This study compared Modic changes seen in whiplash patients 10 years after the injury with those observed in asymptomatic volunteers.

METHODS

This is a follow-up study of 133 patients who suffered whiplash injuries in 1994-1996 and underwent MRI with a superconductive imager (63 men, 70 women, mean age 49.6±15.3 years, mean follow-up 11.4 years). In addition, 223 healthy volunteers who underwent MRI during the same period were included as controls (123 men, 100 women, mean age 50.5±15.0 years, mean follow-up 11.6 years). All participants underwent follow-up MRI. We examined all participants for Modic changes, and investigated relationships between Modic changes and clinical symptoms or potentially related factors.

RESULTS

Modic changes were observed in 4 patients (3%) and at 7 intervertebral levels in the initial study, and in 17 patients (12.8%) and at 30 intervertebral levels at the follow-up. Modic Type 2 changes were the most prevalent in the whiplash patients in both the initial and follow-up studies. There was no significant difference in the percentage of whiplash patients versus control subjects with positive Modic changes, either at the initial study or at follow-up. Modic changes were not related to clinical symptoms present at follow-up, but were associated with preexisting disc degeneration. There was no association between Modic changes and the details of the car accident that caused the injury.

CONCLUSIONS

While Modic changes became more common in whiplash patients in the 10-year period after the accident, they occurred with a similar frequency in control subjects. We did not find any association between Modic changes and the nature of the car accident in which the whiplash occurred. Modic changes found in whiplash patients may be a result of the physiological ageing process rather than pathological findings relating to the whiplash injury.

Quantifying cervical-spine curvature using Bézier splines

Knowledge of the distributions of cervical-spine curvature is needed for computational studies of cervical-spine injury in motor-vehicle crashes. Many methods of specifying spinal curvature have been proposed, but they often involve qualitative assessment or a large number of parameters. The objective of this study was to develop a quantitative method of characterizing cervical-spine curvature using a small number of parameters. 180 sagittal X-rays of subjects seated in automotive posture with their necks in neutral, flexed, and extended postures were collected in the early 1970s. Subjects were selected to represent a range of statures and ages for each gender. X-rays were reanalyzed using advanced technology and statistical methods. Coordinates of the posterior margins of the vertebral bodies and dens were digitized. Bézier splines were fit through the coordinates of these points. The interior control points that define the spline curvature were parameterized as a vector angle and length. By defining the length as a function of the angle, cervical-spine curvature was defined with just two parameters: superior and inferior Bézier angles. A classification scheme was derived to sort each curvature by magnitude and type of curvature (lordosis versus S-shaped versus kyphosis; inferior or superior location). Cervical-spine curvature in an automotive seated posture varies with gender and age but not stature. Average values of superior and inferior Bézier angles for cervical spines in flexion, neutral, and extension automotive postures are presented for each gender and age group. Use of Bézier splines fit through posterior margins offers a quantitative method of characterizing cervical-spine curvature using two parameters: superior and inferior Bézier angles.

Cross-sectional area of the posterior extensor muscles of the cervical spine in whiplash injury patients versus healthy volunteers--10 year follow-up MR study

INTRODUCTION

Long-term follow-up studies focusing on the posterior extensor muscles in patients suffering from whiplash injury are scarce. The purpose of this study was to elucidate the changes in the posterior extensor muscles 10 years after whiplash injury.

METHODS

Twenty-three patients who had suffered from whiplash injury in 1994-1996 and had undergone MRI using a 1.5-T superconductive imager participated in this follow-up study (13 males, 10 females, mean age 51.8 years, mean follow-up 11.5 years). In addition, 60 healthy volunteers who had undergone MRI in the same period were included as controls (36 males, 24 females, mean age 47.8 years, mean follow-up 11.1 years). All participants underwent follow-up MRI. The cross-sectional areas of the deep posterior muscles (CSA) including the multifidus, semispinalis cervicis, semispinalis capitis, and splenius capitis were digitally measured at C3-4, C4-5, and C5-6 using NIH image. The long-term changes in the CSA were compared between the two groups. In addition, correlations between the CSA and cervical spine-related symptoms were evaluated.

RESULTS

The mean total CSA per patient (the sum of the area from C3-4 to C5-6) was 4811.6±878.4 mm(2) in the whiplash patients and 4494.9±1032.7 mm(2) in the controls at the initial investigation (p=0.20), and 5173.4±946.1 mm(2) and 4713.0±1065.3 mm(2) at the follow-up (p=0.07). The mean change in CSA over time was 361.8±804.9 mm(2) in the whiplash patients and 218.1±520.7 mm(2) in the controls (p=0.34). Ten whiplash patients (43.5%) had neck pain and 11 (47.8%) had shoulder stiffness. However, there was no difference in the change in CSA over time between the symptomatic and asymptomatic patients.

CONCLUSIONS

There was no significant difference in the change in CSA between whiplash patients and healthy volunteers after a 10-year follow-up period. In both groups, the cross-sectional area slightly increased at follow-up. In addition, there was no association between the change in CSA and clinical symptoms such as neck and shoulder pain. These results suggest that whiplash injury is not associated with symptomatic atrophy of the posterior cervical muscles over the long term.

Prospective ten-year follow-up study comparing patients with whiplash-associated disorders and asymptomatic subjects using magnetic resonance imaging

STUDY DESIGN

A prospective 10-year follow-up study of patients with whiplash-associated disorders (WAD) and asymptomatic volunteers.

OBJECTIVE

To clarify long-term impact of whiplash injury on patient's symptoms and on magnetic resonance imaging (MRI) findings of the cervical spine.

SUMMARY OF BACKGROUND DATA

Long-term prognosis of WAD has not been fully elucidated.

METHODS

Between 1993 and 1996, we conducted cross-sectional comparative study of 508 acute WAD patients and 497 asymptomatic volunteers, all of whom underwent MRI of the cervical spine. For this follow-up study, 133 WAD patients and 223 control subjects were recruited again. All participants underwent follow-up MRI and physical examination, and answered to questionnaires regarding neck symptoms. Evaluation of MRI included decrease in signal intensity of discs, posterior disc protrusion, disc space narrowing, and foraminal stenosis using 2 to 4 numerical grades. Increase in the numerical grades by one or more was considered to be progression of degenerative changes.

RESULTS

Progression of decrease in signal intensity was observed in 109 WAD patients (82.0%), and 132 control subjects (59.2%), (age, sex adjusted odds ratio [OR]: 3.06), posterior disc protrusion in 101 (75.9%) and in 155 (69.5%) (OR = 1.46), disc space narrowing in 33 (24.8%) and in 59 (26.5%) (OR = 0.98), and foraminal stenosis in 6 (4.5%), and in 20 (9.0%) (OR = 0.52), respectively. Neck pain was observed in 34 WAD patients (25.6%) and 22 control subjects (9.9%) (P < 0.0001). There was no statistically significant correlation between neck pain and progression in each MR finding in either group.

CONCLUSION

The results of this study suggest that, although some WAD patients are more likely to suffer from long-lasting neck pain, MRI findings cannot explain the symptoms.

Neck muscle strength before and after cervical laminoplasty: relation to axial symptoms

STUDY DESIGN

A prospective study to investigate serial changes in neck muscle strength before and after cervical laminoplasty.

OBJECTIVES

To examine the correlation between neck muscle strength and axial symptoms, and to clarify the risk factors for axial symptoms.

SUMMARY OF BACKGROUND DATA

Axial symptoms are common complications after posterior cervical spinal surgery. Although several technical considerations have reduced axial symptoms, the causes of axial symptoms are still largely unknown. Previous studies have indicated that neck muscle strength is reduced in patients with neck pain.

MATERIALS AND METHODS

Nineteen consecutive patients underwent cervical expansive laminoplasty for cervical spondylotic myelopathy. Age, sex, operative time, blood loss, clinical results, cervical curvature, range of motion, visual analog scale (VAS) for axial symptoms, and manual muscle strengths were examined before and after surgery. At 3 and 12 months, these factors were compared statistically between the no pain (NP) group (VAS <3) and the pain (P) group (VAS >or=3). The correlation between VAS and neck muscle strength, and the reduction in neck muscle strength in extension were analyzed statistically.

RESULTS

Six patients (31.5%) complained of axial symptoms at 3 months, and the symptoms continued in 3 patients (15.8%) at 12 months. At 3 months, cervical lordosis was 15.7 degrees in the NP group and 5.0 degrees in the P group, and neck strength in extension was 104.9% and 61.8%, respectively. At 12 months, neck strength in extension was 124.3% and 62.2%, respectively. These differences were statistically significant. The correlation between neck pain VAS and neck muscle strength, and the reduction in neck muscle strength in extension were statistically significant.

CONCLUSIONS

Neck muscle strength recovered to the preoperative value by 3 months and increased to 120% by 12 months in the NP group, whereas in the P group, neck muscle strength remained reduced by 60% and did not recover. Neck muscle strength and axial symptoms were strongly correlated.

Does the sagittal alignment of the cervical spine have an impact on disk degeneration? Minimum 10-year follow-up of asymptomatic volunteers

There have been few studies that investigated and clarified the relationships between progression of degenerative changes and sagittal alignment of the cervical spine. The objective of the study was to longitudinally evaluate the relationships among progression of degenerative changes of the cervical spine with age, the development of clinical symptoms and sagittal alignment of the cervical spine in healthy subjects. Out of 497 symptom-free volunteers who underwent MRI and plain radiography of the cervical spine between 1994 and 1996, 113 subjects (45 males and 68 females) who responded to our contacts were enrolled. All subjects underwent another MRI at an average of 11.3 years after the initial study. Their mean age at the time of the initial imaging was 36.6 +/- 14.5 years (11-65 years). The items evaluated on MRI were (1) decrease in signal intensity of the intervertebral disks, (2) posterior disk protrusion, and (3) disk space narrowing. Each item was evaluated using a numerical grading system. The subjects were divided into four groups according to the age and sagittal alignment of the cervical spine, i.e., subjects under or over the age of 40 years, and subjects with the lordosis or non-lordosis type of sagittal alignment of the cervical spine. During the 10-year period, progression of decrease in signal intensity of the disk, posterior disk protrusion, and disk space narrowing were recognized in 64.6, 65.5, and 28.3% of the subjects, respectively. Progression of posterior disk protrusion was significantly more frequent in subjects over 40 years of age with non-lordosis type of sagittal alignment. Logistic regression analysis revealed that stiff shoulder was closely correlated with females (P = 0.001), and that numbness of the upper extremity was closely correlated with age (P = 0.030) and male (P = 0.038). However, no significant correlation between the sagittal alignment of the cervical spine and clinical symptoms was detected. Sagittal alignment of the cervical spine had some impact on the progression of degenerative changes of the cervical spine with aging; however, it had no correlation with the occurrence of future clinical symptoms.

Whiplash injury

This review discusses the causes, outcome and prevention of whiplash injury, which costs the economy of the United Kingdom approximately £3.64 billion per annum. Most cases occur as the result of rear-end vehicle collisions at speeds of less than 14 mph. Patients present with neck pain and stiffness, occipital headache, thoracolumbar back pain and upper-limb pain and paraesthesia. Over 66% make a full recovery and 2% are permanently disabled. The outcome can be predicted in 70% after three months.

Parametric and subject-specific finite element modelling of the lower cervical spine. Influence of geometrical parameters on the motion patterns

Morphometrical and postural features of the cervical spine are supposed to significantly influence its biomechanical behaviour. However, the effects of these geometrical parameters are quite difficult to evaluate. An original numerical method is proposed in order to automatically generate parametric and subject-specific meshes of the lower cervical spine. Sixteen finite element models have been built from cadaver specimens using low dose biplanar X-rays. All the generated meshes fulfilled the quality criteria. A preliminary evaluation was performed on the C5-C6 functional units using a database of previous experimental tests. The principal and coupled motions were simulated. The responses of the numerical models were within the experimental standard deviation corridors in most cases. Rotation-moment relationships were then compared to assess the influence of geometry on the mechanical response. Geometry was found to play a significant role in the motion patterns.

Assessment of neck pain and its associated disorders: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders

STUDY DESIGN

Best evidence synthesis.

OBJECTIVE

To critically appraise and synthesize the literature on assessment of neck pain.

SUMMARY OF BACKGROUND DATA

The published literature on assessment of neck pain is large and of variable quality. There have been no prior systematic reviews of this literature.

METHODS

The Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders conducted a critical review of the literature (published 1980-2006) on assessment tools and screening protocols for traumatic and nontraumatic neck pain.

RESULTS

We found 359 articles on assessment of neck pain. After critical review, 95 (35%) were judged scientifically admissible. Screening protocols have high predictive values to detect cervical spine fracture in alert, low-risk patients seeking emergency care after blunt neck trauma. Computerized tomography (CT) scans had better validity (in adults and elderly) than radiographs in assessing high-risk and/or multi-injured blunt trauma neck patients. In the absence of serious pathology, clinical physical examinations are more predictive at excluding than confirming structural lesions causing neurologic compression. One exception is the manual provocation test for cervical radiculopathy, which has high positive predictive value. There was no evidence that specific MRI findings are associated with neck pain, cervicogenic headache, or whiplash exposure. No evidence supports using cervical provocative discography, anesthetic facet, or medial branch blocks in evaluating neck pain. Reliable and valid self-report questionnaires are useful in assessing pain, function, disability, and psychosocial status in individuals with neck pain.

CONCLUSION

The scientific evidence supports screening protocols in emergency care for low-risk patients; and CT-scans for high-risk patients with blunt trauma to the neck. In nonemergency neck pain without radiculopathy, the validity of most commonly used objective tests is lacking. There is support for subjective self-report assessment in monitoring patients' course, response to treatment, and in clinical research.

Assessment of neck pain and its associated disorders: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders

STUDY DESIGN

Best evidence synthesis.

OBJECTIVE

To critically appraise and synthesize the literature on assessment of neck pain.

SUMMARY OF BACKGROUND DATA

The published literature on assessment of neck pain is large and of variable quality. There have been no prior systematic reviews of this literature.

METHODS

The Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders conducted a critical review of the literature (published 1980-2006) on assessment tools and screening protocols for traumatic and nontraumatic neck pain.

RESULTS

We found 359 articles on assessment of neck pain. After critical review, 95 (35%) were judged scientifically admissible. Screening protocols have high predictive values to detect cervical spine fracture in alert, low-risk patients seeking emergency care after blunt neck trauma. Computerized tomography (CT) scans had better validity (in adults and elderly) than radiographs in assessing high-risk and/or multi-injured blunt trauma neck patients. In the absence of serious pathology, clinical physical examinations are more predictive at excluding than confirming structural lesions causing neurologic compression. One exception is the manual provocation test for cervical radiculopathy, which has high positive predictive value. There was no evidence that specific MRI findings are associated with neck pain, cervicogenic headache, or whiplash exposure. No evidence supports using cervical provocative discography, anesthetic facet, or medial branch blocks in evaluating neck pain. Reliable and valid self-report questionnaires are useful in assessing pain, function, disability, and psychosocial status in individuals with neck pain.

CONCLUSION

The scientific evidence supports screening protocols in emergency care for low-risk patients; and CT-scans for high-risk patients with blunt trauma to the neck. In nonemergency neck pain without radiculopathy, the validity of most commonly used objective tests is lacking. There is support for subjective self-report assessment in monitoring patients' course, response to treatment, and in clinical research.

The burden and determinants of neck pain in whiplash-associated disorders after traffic collisions: results of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders

STUDY DESIGN

Best evidence synthesis.

OBJECTIVE

To undertake a best evidence synthesis on the burden and determinants of whiplash-associated disorders (WAD) after traffic collisions.

SUMMARY OF BACKGROUND DATA

Previous best evidence synthesis on WAD has noted a lack of evidence regarding incidence of and risk factors for WAD. Therefore there was a warrant of a reanalyze of this body of research.

METHODS

A systematic search of Medline was conducted. The reviewers looked for studies on neck pain and its associated disorders published 1980-2006. Each relevant study was independently and critically reviewed by rotating pairs of reviewers. Data from studies judged to have acceptable internal validity (scientifically admissible) were abstracted into evidence tables, and provide the body of the best evidence synthesis.

RESULTS

The authors found 32 scientifically admissible studies related to the burden and determinants of WAD. In the Western world, visits to emergency rooms due to WAD have increased over the past 30 years. The annual cumulative incidence of WAD differed substantially between countries. They found that occupant seat position and collision impact direction were associated with WAD in one study. Eliminating insurance payments for pain and suffering were associated with a lower incidence of WAD injury claims in one study. Younger ages and being a female were both associated with filing claims or seeking care for WAD, although the evidence is not consistent. Preliminary evidence suggested that headrests/car seats, aimed to limiting head extension during rear-end collisions had a preventive effect on reporting WAD, especially in females.

CONCLUSION

WAD after traffic collisions affects many people. Despite many years of research, the evidence regarding risk factors for WAD is sparse but seems to include personal, societal, and environmental factors. More research including, well-defined studies with accurate denominators for calculating risk, and better consideration of confounding factors, are needed.

Finite element model of the human neck during omni-directional impacts. Part II: relation between cervical curvature and risk of injury

A detailed 3D FE model of the human neck was used to assess a possible relationship between risk of injury and cervical spine curvature for various impacts. A FE model was previously developed, representing the head and neck of a 50th percentile human with a normal lordotic curvature. The model behaviour was omni-directionally validated for various impacts using published results. For the present study, the model was deformed in order to obtain a straight and a kyphotic curvature, and for each geometry, rear-end, frontal, lateral and oblique impact were simulated. Although results showed similar kinematic patterns, significant differences were found in the distribution and peak values of ligament elongations, forces and moments along the cervical spine for the three configurations. It was concluded that the variability observed on the curvature of the human cervical spine may have a significant influence both on the behaviour and on the risk of injury of the neck during impact.

Conservative treatment of a patient with previously unresponsive whiplash-associated disorders using clinical biomechanics of posture rehabilitation methods

OBJECTIVE

To describe the treatment of a patient with chronic whiplash-associated disorders (WADs) previously unresponsive to multiple physical therapy and chiropractic treatments, which resolved following Clinical Biomechanics of Posture (CBP) rehabilitation methods.

CLINICAL FEATURES

A 40-year-old man involved in a high-speed rear-impact collision developed chronic WADs including cervicothoracic, shoulder, and arm pain and headache. The patient was diagnosed with a confirmed chip fracture of the C5 vertebra and cervical and thoracic disk herniations. He was treated with traditional chiropractic and physical therapy modalities but experienced only temporary symptomatic reduction and was later given a whole body permanent impairment rating of 33% by an orthopedic surgeon.

INTERVENTION AND OUTCOME

The patient was treated with CBP mirror-image cervical spine adjustments, exercise, and traction to reduce forward head posture and cervical kyphosis. A presentation of abnormal head protrusion resolved and cervical kyphosis returned to lordosis posttreatment. His initial neck disability index was 46% and 0% at the end of care. Verbal pain rating scales also improved for neck pain (from 5/10 to 0/10).

CONCLUSION

A patient with chronic WADs and abnormal head protrusion, cervical kyphosis, and disk herniation experienced an improvement in symptoms and function after the use of CBP rehabilitation protocols when other traditional chiropractic and physical therapy procedures showed little or no lasting improvement.

Cervical spine geometry in the automotive seated posture: variations with age, stature, and gender

In the mid 1970s, UMTRI investigated the biomechanical properties of the head and neck using 180 "normal" adult subjects selected to fill eighteen subject groups based on age (young, mid-aged, older), gender, and stature (short, medium, and tall by gender). Lateral-view radiographs of the subjects' cervical spines and heads were taken with the subjects seated in a simulated automotive neutral posture, as well as with their necks in full-voluntary flexion and full-voluntary extension. Although the cervical spine and lower head geometry were previously measured manually and documented, new technologies have enabled computer digitization of the scanned x-ray images and a more comprehensive and detailed analysis of the variation in cervical spine and lower head geometry with subject age, stature, and gender. After scanning the radiographic images, 108 skeletal landmarks on the cervical vertebrae and 10 head landmarks were digitized. The resulting database of cervical spine and head geometry was used to study cervical spine curvature, vertebral dimensions, and head/neck orientation as functions of age, gender, and stature. The data were used to characterize neutral posture cervical spine curvatures using two methods: a curvature index and Bézier spline functions. Lateral-view vertebral dimensions were also calculated for each subject, and a cascading series of equations was developed to estimate vertebral size and shape for a selected age, stature, and gender. The orientation of the cervical spine was defined using a neck chord angle, where the neck chord was varied to use different anatomical landmarks and estimates of joint centers for the top and bottom of the neck chord. Results from the study have been incorporated into a MS-Access based software package that allows researchers and modelers to generate cervical spine geometries for occupants of a specified age, gender, and stature. The program allows selection of individual occupants from the database that meet age, stature, gender, or curvature criteria, or creation of a composite cervical spine geometry representative of the selected age, gender, and stature. This tool will allow researchers to configure and vary cervical spine geometry in computer models and experimental test setups used to study head and neck impact response and injury risk.

Whiplash: Pathophysiology, diagnosis, treatment, and prognosis

We have reviewed the literature relevant to pathophysiology, diagnosis, treatment, and prognosis of whiplash-associated disorder (WAD) since 1995 and provided a brief summary of literature pertaining to forces action on the head and neck during a motor vehicle accident. The scope of the current review is confined to the Quebec guidelines for WAD grades 1-3 but excludes grade 4 (neck complaints and fracture or dislocation). After excluding papers without scientific data and single case reports or case series with fewer than 20 patients, articles were reviewed for methodological quality. The diagnosis remains clinical. No imaging, physiological, or psychological study provides specific diagnostic criteria. In the acute period up to 2 weeks, soft collars or rest and work-leave do not shorten the duration of neck pain. Sick leave is reduced by high-dose methylprednisolone given within 8 h of injury, but confirmatory studies examining the cost-benefit relationship are needed. In the first 6 months, active as opposed to passive treatment results in improved outcomes. Specific exercise strategies have not been studied. For those with symptoms lasting more than 6 months, percutaneous radio-frequency neurotomy can provide pain relief for many months in those responding to blind local anesthetic facet blocks. Intra-articular corticosteroids are ineffective. Uncontrolled trials suggest that multimodal rehabilitation programs result in improved overall function. The overall prognosis for recovery has varied considerably across studies. Such variability is likely due to differences in case identification methods and whether outcome is assessed in terms of symptoms or the receipt of financial compensation for injury. The impact on prognosis of both collision- and patient-related factors is also reviewed.

Relationship between alignment of upper and lower cervical spine in asymptomatic individuals

OBJECT

The aim of this study was to establish standard values for the normal alignment of the upper cervical spine and to clarify its relationship with the lower cervical spine in terms of alignment

METHODS

Three hundred thirteen asymptomatic volunteers (155 men and 158 women) participated in this study. Lateral radiographs were obtained with the neck in neutral position, and the angles formed by the occiput (Oc) and the axis, the atlas and the axis, and C-2 to C-7 were measured. The mean Oc-C2 angle was 14.5 +/- 8 degrees in men and 16 +/- 8.5 degrees in women; the mean C1-2 angle was 26.5 +/- 7 degrees and 28.9 +/- 6.7 degrees, respectively; and the mean C2-7 angle was 16.2 +/- 12.9 degrees and 10.5 +/- 10.3 degrees, respectively. Although weak, statistically significant negative correlation was observed between Oc-C2 and C2-7 angles (r = -0.31 in men and -0.37 in women), and between C1-2 and C2-7 angles (r = -0.22 in men and -0.22 in women). The correlation coefficient between the Oc-C2 and C2-7 angles was greater than that between the C1-2 and C2-7angles.

CONCLUSIONS

Such relationships between alignment of the upper and lower cervical spines should be taken into consideration when performing occipitocervical fusion.

Is the sagittal configuration of the cervical spine changed in women with chronic whiplash syndrome? A comparative computer-assisted radiographic assessment

OBJECTIVE

To reveal whether women with chronic whiplash-associated disorder (WAD) symptoms, grade I-II, demonstrate regional and/or segmental radiographic signs of altered cervical lordosis.

DESIGN

Case-control study.

SETTING

Radiography department at a university hospital.

PARTICIPANTS

Three age-balanced groups comprising 120 women. The case group included women with chronic whiplash syndrome (n = 41), and the control group included women with chronic insidious onset neck pain (n = 39) and an asymptomatic group (n = 40), who were given baseline data. The sample was referred from informed doctors and physiotherapists.

INTERVENTION

The women sat in a standardized sitting position and radiographs were taken in a lateral position with fluoroscopic control for alignment.

OUTCOME MEASURES

Two distinct measurements were taken; 1 of the angles of the upper and lower cervical curvatures, respectively, and 1 of the angles between the inferior borders of each pair of vertebrae in the lower cervical spine. The 3 groups were compared on the ratio of the lower to upper cervical spine angles and on the mean angular values for each segment in the cervical spine.

RESULTS

The whiplash group showed a decreased ratio between the lower versus upper cervical spine but comparisons between groups were not statistically significant. The whiplash group was in a significantly more flexed position at the C4-C5 level compared with the asymptomatic group (P =.007). The reliability measures have to be strengthened to render these results definitely conclusive.

CONCLUSION

The whiplash group exhibited a different configuration of cervical lordosis. This is clinically important and needs to be studied more closely.

Comparison of axial and flexural stresses in lordosis and three buckled configurations of the cervical spine

OBJECTIVE

To calculate and compare combined axial and flexural stresses in lordosis versus buckled configurations of the sagittal cervical curve.

DESIGN

Digitized measurements from lateral cervical radiographs of four different shapes were used to calculate axial loads and bending moments on the vertebral bodies of C2-C7.Background. Osteoarthritis and spinal degeneration are factors in neck and back pain. Calculations of stress in clinically occurring configurations of the sagittal cervical spine are rare.

METHODS

Center of gravity of the head (inferior-posterior sella turcica) and vertebral body margins were digitized on four different lateral cervical radiographs: lordosis, kyphosis, and two "S"-shapes. Polynomials (seventh degree) and stress concentrations on the concave and convex margins were derived for the shape of the sagittal cervical curvatures from C1 to T1. Moments of inertia were determined from digitizing and the use of an elliptical shell model of cross-section. Moment arms from a vertical line through the center of gravity of the head to the atlas and scaled neck extensor moment arms from the literature were used to compute the vertical component of extensor muscle effort. Segmental lever arms were calculated from a vertical line through C1 to each vertebra.

RESULTS

In lordosis, anterior and posterior stresses in the vertebral body are nearly uniform and minimal. In kyphotic areas, combined stresses changed from tension to compression at the anterior vertebral margins and were very large (6-10 times as large in magnitude) compared to lordosis. In kyphotic areas at the posterior vertebral body, the combined stresses changed from compression (in lordosis) to tension.

CONCLUSIONS

The stresses in kyphotic areas are very large and opposite in direction compared to a normal lordosis. This analysis provides the basis for the formation of osteophytes (Wolff's Law) on the anterior margins of vertebrae in kyphotic regions of the sagittal cervical curve. This indicates that any kyphosis is an undesirable configuration in the cervical spine. Relevance. Osteophytes and osteoarthritis are found at areas of altered stress and strain. Axial and flexural stresses at kyphotic areas in the sagittal cervical spine are abnormally high.

Whiplash Injuries

The term "whiplash" is not a medical diagnosis, but is the result of soft-tissue trauma to the neck. A whiplash injury occurs as a result of a sudden acceleration or deceleration of the head and neck with respect to the body. This article recommends that patient treatment be individualized.