The efficacy of sagittal cervical spine subtyping: Investigating radiological classification methods within 150 asymptomatic participants

A New Index for Cervical Curvature Evaluation - Relative Cervical Curvature Area

OBJECTIVE

To put forward a new index of cervical curvature evaluation - relative cervical curvature area, and a new classification of cervical spine was proposed according to the relative cervical curvature area.

METHODS

A total of 167 subjects with cervical spondylosis were included in the study. Firstly, 119 subjects were selected to measure C2-C7 lordosis angle by Cobb angle method, Harrison posterior tangent method, and Jackson physiological stress line method, and then their relative cervical curvature area, C1-C7 Cobb angle, C7 slope, and T1 slope were measured. The correlation between relative cervical curvature area and 3 measurement methods and common sagittal parameters was analyzed. According to the angle classification method, we calculated the diagnostic boundary value of the relative cervical curvature area classification, and selected 48 subjects to evaluate its diagnostic efficacy. Finally, 119 subjects were re-evaluated according to the diagnostic threshold and the number of intersections to verify the feasibility of the new classification.

RESULTS

The results showed that the relative cervical curvature area index had good intraobserver and interobserver repeatability. Relative cervical curvature area was correlated with Harrison posterior tangent method (r = 0.930), Cobb angle method (r = 0.886), and Jackson physiological stress line method (r = 0.920), and correlated with C1-C7 Cobb angle, C7 slope, and T1 slope. The relative cervical curvature area has a good diagnostic performance for distinguishing patients with lordosis, straightening, and kyphosis. According to the new classification of cervical spine, 119 subjects were divided into 57 simple lordosis, 11 simple straightening, 4 simple kyphosis, 26 S-type, and 21 RS-type.

CONCLUSIONS

The relative cervical curvature area uses the area parameter instead of the original angle parameter and distance parameter to incorporate the change of segmental curvature, which makes up for the shortcomings of the Cobb angle method that only evaluates the curvature of 2 vertebrae, and better reflects the cervical curvature. Studies have shown that relative cervical curvature area has good repeatability and diagnostic value, and found that it has a good correlation with common cervical sagittal parameters. The new classification of cervical spine makes up for the disadvantage that the angle classification method cannot distinguish between S-type and RS-type, and initially proposes to use the number of intersections and the relative absolute value area to reflect the severity of S-type.

Do key measurement parameters derived from specific cervical vertebral segments differ between lordotic and non-lordotic cervical spine alignments? A study of asymptomatic young adults

BACKGROUND

Measurement parameters derived from specific cervical vertebral segments (e.g., C2 slope) can provide clinicians with important information on cervical sagittal balance and guide pre- and post-surgical decision-making processes. It is unclear however, what constitutes typical values for these types of measurements in an asymptomatic population of young adults, whether values change depending upon the classification of the cervical spine's global alignment, and if any non-lordotic cervical subtypes display values that are comparable to those reported for pre-surgery patients.

METHODS

Neutral lateral cervical radiographs of 150 asymptomatic participants (18-30 years) were taken. Global cervical alignment was classified as lordotic or one of four non-lordotic subtypes using a multi-method subtyping protocol. Four key measurement parameters - the anterior translation of the head measure (ATHM), C0-C2 angle, C2 slope, and C7 slope - were derived from specific cervical segments. Independent samples t-tests were used to compare lordotic and non-lordotic groups.

RESULTS

There was considerable variation in the four key measurement parameters amongst this asymptomatic population of young adults. Thirty-four percent of the sample were classified as lordotic and 66% were classified as non-lordotic. There was a significant difference (p ≤ 0.0125) between lordotic and non-lordotic groups for the C0-C2 angle, C2 slope and C7 slope. There was no difference between groups for the ATHM (p ≥ 0.0125). Within the non-lordotic group, the global-kyphotic (GK) subtype had the largest mean C2 slope, largest mean C0-C2 angle, and smallest mean C7 slope.

CONCLUSIONS

Long term prospective investigations are required to determine whether possible biomarkers (alignment parameters/radiological measurements) for spinal degenerative changes can be identified so that early interventions can be put in place to try and reduce the impact of neck pain on society.

The Influence of Cervical Spine Angulation on Symptoms Associated With Wearing a Rigid Neck Collar

Introduction:

Rigid cervical spine collars can be used to maintain the position of the cervical spine following injury or surgery. However, they have been associated with difficulty swallowing, pressure sores and pain, particularly in older patients. We aimed to investigate the relationship between cervical spine angulation, a rigid neck collar and neck pain in healthy young and older adults.

Methods:

Twenty healthy young adults aged 25 ± 3 years and 17 healthy older adults aged 80 ± 8 years were tested. Magnetic resonance imaging scans of their cervical spines were taken before and after the rigid neck collar was worn for 1 hour. Measurement of vertebral angulation involved digitization of the scans and joint angle calculations using image processing software. Pain was quantified before and after the collar was worn, using a visual analogue scale.

Results:

Pain scores increased in the young group after the collar was worn (p = 0.001). The older group showed no difference in pain score after the collar was worn. Statistical tests showed no significant correlations between the change in cervical angles and the change in pain scores after the collar was worn.

Discussion:

The aging process may contribute to the changing distribution of subcutaneous tissue and increase risk of symptoms associated with wearing a collar. Oesophageal compression is not a result of collar use.

Conclusion:

There is no correlation between cervical spine vertebrae angulation and symptoms associated with wearing a neck collar. Generally, older individuals have greater cervical lordosis angles, and more straight and lordotic neck shapes. Older individuals may be more prone to skin-interface pressures from the neck collar than younger individuals.

Internal and external sagittal craniovertebral alignment: A comparison between radiological and photogrammetric approaches in asymptomatic participants

BACKGROUND

Photogrammetric measures are a commonly applied, highly reliable tool for appraising craniovertebral postures during clinical assessments, rehabilitation, and research interventions.

OBJECTIVE

This study aimed to compare and contrast three external measures of postural alignment (EMPA) using photogrammetric and radiological approaches, and to discuss whether the craniovertebral angle (CVA) reflects the shape of the underlying cervical spine.

DESIGN

Cross Sectional Correlation Study.

METHOD

Young adults attended three assessment sessions (S1, S2 and S3). S1 involved a standardised photogrammetric protocol. S2 involved radiographic image acquisition. S3 followed the same protocol in S1 but excluded the self-balancing procedure. Each session's EMPA were compared through either paired or independent samples t-tests. The different radiographic cervical subtypes and their corresponding CVAs were assessed.

RESULTS

There were no significant differences in any EMPA between the two photogrammetric sessions. The CVA was the only EMPA to show a significant difference between photogrammetric (S3) and radiographic approaches. Cervical subtype variability is present throughout the full CVA range.

CONCLUSIONS

Despite the statistically significant difference in the CVA between approaches, the mean difference was small and unlikely to be clinically meaningful. Accordingly, the quantification of EMPA can be undertaken with high levels of precision and reliability using standardised photogrammetric procedures. The CVA, however, does not provide an indication of the shape of the underlying cervical spine. The distinct radiological differences in the inter-segmental orientation of each vertebral motion segment in conjunction with the differences in the overall global cervical alignment, both within and between participants, negate this possibility.

A systematic review with meta-analysis on functional changes associated with neck pain in adolescents

BACKGROUND

Neck pain (NP) is highly prevalent in young people, but there has been no systematic review synthetizing the functional changes associated with this in adolescents. The aim of the present study was to identify and assess critically the evidence on the functional changes associated with NP in adolescents, specifically for: (a) posture; (b) postural control; (c) range of motion; (d) proprioception; (e) muscle function; and (f) sensory threshold.

METHODS

We searched PubMed, ScienceDirect, Web of Science, PEdro, Scielo, Scopus and Academic Search Premier databases for relevant studies. Two reviewers screened studies for inclusion and assessed the quality of the included studies. One reviewer extracted relevant data from the included studies. A meta-analysis was performed for studies that measured forward head posture (FHP).

RESULTS

Ten studies were included and a total of 15 comparisons for different variables were made. When compared with adolescents without NP, those with NP showed no differences in cervicothoracic posture or FHP. However, statistically significant differences were found for range of motion: weighted mean difference (WMD) from -14.0° (-21.1° to -1.1°) to 9.4° (2.8° to 16.0°); flexor muscle endurance: WMD -11.4 (-21.8 to -0.9) s; extensor muscle endurance: WMD -42.0 (-77.8 to -6.3) s; joint repositioning error for right and left rotation: WMD 1.9° (0.8° to 2.9°) and 2.4° (1.3° to 3.5°), respectively; and pressure pain threshold: WMD from -15.6 (-18.5 to -12.8) to -9.3 (-11.3 to 7.2) N/ cm².

CONCLUSION

There is very limited to limited evidence that there is no difference in posture between adolescents with and without NP, and that there is a difference for range of motion, muscle function, proprioception and pressure pain threshold.

The effect of cervical spine subtypes on center of pressure parameters in a large asymptomatic young adult population

BACKGROUND

Recent research highlighted that non-lordotic subtypes are common within an asymptomatic population of young adults. The potential mechanisms responsible for the decreased postural control witnessed in healthy participants exhibiting non-lordotic cervical alignment are unclear.

RESEARCH QUESTION

Therefore, the aim of this study is to compare and contrast asymptomatic radiographically derived sagittal cervical alignment subtypes with Center of Pressure (CoP) parameters.

METHODS

In this cross-sectional study strict asymptomatic inclusion criteria were met by 150 of the original 182 volunteers. All radiographs were assessed using a multi-method subtype system with participants classified into lordotic and non-lordotic groups. Participants performed 90s narrow stance trials with their eyes closed whilst standing on both a firm surface (FS) and compliant surface (CS) (3 trials per surface). CoP parameters were recorded from a force platform sampling at 100 Hz. Nonparametric statistical tests were conducted to assess differences between groups for each surface type and to determine differences in CoP parameters between FS and CS types.

RESULTS

Significant differences were found between groups on both surfaces for the anterior to posterior range (FS: p = 0.013; CS: p = 0.023), total excursion (FS: p = 0.029; CS: p = 0.005) and mean velocity of total excursion (FS: p = 0.032; CS: p = 0.004).

SIGNIFICANCE

Our data suggest that sagittal plane cervical alignment is a measure capable of distinguishing between the postural control of asymptomatic lordotic and non-lordotic young adult participants on both surfaces types. Furthermore, decreased postural control is present in asymptomatic participants across all non-lordotic subtypes and is not isolated exclusively to those with forward head posture. Consequently, future research endeavours should investigate the clinical significance of these non-lordotic findings in relation to both the potential for early cervical osseous degeneration and the transitional stages of non-specific pain sufferers from previously asymptomatic young adults.