Relationship among cervical, thoracic, and lumbopelvic sagittal alignment in healthy adults

Sex-dependent evolution of whole-body postural alignment with age

PURPOSE

The goal of this study was to explore sex-related variations of global alignment parameters and their distinct evolution patterns across age groups.

METHODS

This multicentric retrospective study included healthy volunteers with full-body biplanar radiographs in free-standing position. All radiographic data were collected from 3D reconstructions: global and lower limb parameters, pelvic incidence (PI) and sacral slope (SS). Lumbar lordosis (LL), thoracic kyphosis (TK) and cervical lordosis (CL) were also assessed as well as the lumbar and thoracic apex, and thoracolumbar inflexion point. The population was divided into five 5 age groups: Children, Adolescents, Young, Middle-Aged and Seniors.

RESULTS

This study included 861 subjects (53% females) with a mean age of 34 ± 17 years. Mean PI was 49.6 ± 11.1 and mean LL was - 57.1 ± 11.6°. Females demonstrated a PI increase between Young and Middle-Aged groups (49 ± 11° vs. 55 ± 12°, p < 0.001) while it remained stable in males. SS and LL increased with age in females while remaining constant in males between Children and Middle-aged and then significantly decreased for both sexes between Middle-Aged and Seniors. On average, lumbar apex, inflexion point, and thoracic apex were located one vertebra higher in females (p < 0.001). After skeletal maturity, males had greater TK than females (64 ± 11° vs. 60 ± 12°, p = 0.04), with significantly larger CL (-13 ± 10° vs. -8 ± 10°, p = 0.03). All global spinal parameters indicated more anterior alignment in males.

CONCLUSION

Males present more anteriorly tilted spine with age mainly explained by a PI increase in females between Young and Middle-Aged, which may be attributed to childbirth. Consequently, SS and LL increased before decreasing at senior age.

Capturing the cervical spine shape: Angular measurements versus geometric morphometric methods

The cervical spine manifests a wide shape variation. However, the traditional methods to evaluate the cervical spine curve were never tested against its actual shape. The study's main aim was to determine whether the shape classification of the cervical spine, based on traditional angular measurements, coincides with each other and with the shape captured by the 2D landmark-based geometric morphometric method. The study's second aim was to reveal the associations between the cervical spine shape and the demographic parameters, the head's position, and the spine's sagittal balance. CT scans of the cervical spine of 163 individuals were evaluated to achieve these goals. The shape was assessed by measuring the C2-C7 Cobb angle (CA), the C2-C7 posterior tangent angle (PTA), the curvedness of the arch, and by a 2D landmark-based geometric morphometric method. The position of the head and the sagittal balance of the spine were evaluated by measuring the foramen magnum-C2 Cobb angle (FMCA) and the T1 slope angle (T1SA), respectively. Based on the size of the angle measured, each individual was classified into one of the three cervical 'shape groups' (lordotic, straight, and kyphotic). We found that cervical lordosis was the dominant shape regardless of the measuring methods utilized (46.6%-54.6%), followed by straight neck (28.2%-30.1%), and kyphosis (15.3%-25.2%); however, about a third of the 163 individuals were classified into a different shape group using the CA and PTA methods. The cervical spine angle was sex-independent and age-dependent. The T1SA was significantly correlated with CA and PTA (r = 0.640 and r = 0.585, respectively; p < 0.001). In conclusion, the cervical spine shape evaluation is method-dependent and varies with age.

The effect of ethnicity on the age-related changes of spinopelvic characteristics: a systematic review

Aims

Spinopelvic characteristics influence the hip’s biomechanical behaviour. However, to date there is little knowledge defining what ‘normal’ spinopelvic characteristics are. This study aims to determine how static spinopelvic characteristics change with age and ethnicity among asymptomatic, healthy individuals.

Methods

This systematic review followed the Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines to identify English studies, including ≥ 18-year-old participants, without evidence of hip or spine pathology or a history of previous surgery or interventional treatment, documenting lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI). From a total of 2,543 articles retrieved after the initial database search, 61 articles were eventually selected for data extraction.

Results

When all ethnicities were combined the mean values for LL, SS, PT, and PI were: 47.4° (SD 11.0°), 35.8° (SD 7.8°), 14.0° (SD 7.2°), and 48.8° (SD 10°), respectively. LL, SS, and PT had statistically significant (p < 0.001) changes per decade at: −1.5° (SD 0.3°), −1.3° (SD 0.3°), and 1.4° (SD 0.1°). Asian populations had the largest age-dependent change in LL, SS, and PT compared to any other ethnicity per decade at: −1.3° (SD 0.3°) to −0.5° (SD 1.3°), –1.2° (SD 0.2°) to −0.3° (SD 0.3°), and 1.7° (SD 0.2°) versus 1.1° (SD 0.1°), respectively.

Conclusion

Ageing alters the orientation between the spine and pelvis, causing LL, SS, and PT to modify their orientations in a compensatory mechanism to maintain sagittal alignment for balance when standing. Asian populations have the largest degree of age-dependent change to their spinopelvic parameters compared to any other ethnicity, likely due to their lower PI.

Cite this article: Bone Joint Res 2023;12(4):231–244.

2022 Bern Consensus Statement on Shoulder Injury Prevention, Rehabilitation, and Return to Sport for Athletes at All Participation Levels

There is an absence of high-quality evidence to support rehabilitation and return-to-sport decisions following shoulder injuries in athletes. The Athlete Shoulder Consensus Group was convened to lead a consensus process that aimed to produce best-practice guidance for clinicians, athletes, and coaches for managing shoulder injuries in sport. We developed the consensus via a 2-round Delphi process (involving more than 40 content and methods experts) and an in-person meeting. This consensus statement provides guidance with respect to load and risk management, supporting athlete shoulder rehabilitation, and decision making during the return-to-sport process. This statement is designed to offer clinicians the flexibility to apply principle-based approaches to managing the return-to-sport process within a variety of sporting backgrounds. The principles and consensus of experts working across multiple sports may provide a template for developing additional sport-specific guidance in the future. J Orthop Sports Phys Ther 2022;52(1):11-28. doi:10.2519/jospt.2022.10952.

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.

Global Sagittal Balance of Spine in Asymptomatic Controls: A Systematic Review and Meta-Analysis

OBJECTIVE

To assess the global sagittal balance of spine (GSBS) in asymptomatic controls.

METHODS

PubMed, Scopus, Cochrane library, and Web of Science searched up to July 2020. Studies were screened for the GSB parameters including T1 pelvic angle (TPA), spinosacral angle (SSA), sagittal vertical axis (SVA), C7/sacrofemoral distance ratio (Barrey index), odontoid hip axis (OD-HA), and Full Balance Index (FBI) as measured in asymptomatic participants. A meta-analysis was performed to synthesize pooled estimates. Heterogeneity and publication bias were assessed.

RESULTS

Overall, 76 studies were identified including 12,169 participants (54.7% female) with mean age ranges from 12.0 to 72.9 years old. We used the Newcastle-Ottawa Scale (NOS) to evaluate the quality of studies included in this review. Begg's test did not indicate obvious publication bias. The pooled analysis reveals that the mean (standard deviation) normative values were: 1) age ˃18 years, SSA (°), 127.6 (0.89); SVA absolute value (millimeters), 13.1 (1.13); TPA (°), 9.8 (1.13); T1SPI (°), -4.3 (0.57); and Barrey index absolute value, 0.51 (0.3). The mean value of the OD-HA (°) was reported 2.9 (1.6), and the FBI average value was less than 5°. 2) Age ≤18 years, SSA (°), 132.1 (8.3); SVA absolute value (millimeters), 11.9 (2.0); and Barrey index, -0.7 (8.3). A significant difference was observed between the 2 age groups based on SVA and SSA.

CONCLUSIONS

This paper presents normative data on TPA, SSA, SVA, Barrey index, OD-HA, and FBI as a reference for evaluating/measuring a GSB of spine in asymptomatic controls.

The relationship between thoracic kyphosis and age, and normative values across age groups: a systematic review of healthy adults

Background

Thoracic kyphosis is reported to increase with ageing. However, this relationship has not been systematically investigated. Peoples’ kyphosis often exceeds 40°, but 40° is the widely accepted cut-off and threshold for normality. Consequently, patients may be misclassified. Accurate restoration of kyphosis is important to avoid complications following spinal surgery. Therefore, specific reference values are needed. The objective of the review is to explore the relationship between thoracic kyphosis and age, provide normative values of kyphosis for different age groups and investigate the influence of gender and ethnicity.

Methods

Two reviewers independently conducted a literature search, including seven databases and the Spine Journal, from inception to April 2020. Quantitative observational studies on healthy adults (18 years of age or older) with no known pathologies, and measuring kyphosis with Cobb’s method, a flexicurve, or a kyphometer, were included. Study selection, data extraction, and study quality assessment (AQUA tool) were performed independently by two reviewers. The authors were contacted if clarifications were necessary. Correlation analysis and inferential statistics were performed (Microsoft Excel). The results are presented narratively. A modified GRADE was used for evidence quality assessment.

Results

Thirty-four studies (24 moderate-quality, 10 high-quality) were included (n = 7633). A positive moderate correlation between kyphosis and age was found (Spearman 0.52, p < 0.05, T5-T12). Peoples’ kyphosis resulted greater than 40° in 65% of the cases, and it was significantly smaller in individuals younger than 40 years old (x < 40) than in those older than 60 years old (x > 60) 75% of the time (p < 0.05). No differences between genders were found, although a greater kyphosis angle was observed in North Americans and Europeans.

Conclusion

Kyphosis increases with ageing, varying significantly between x < 40 and x > 60. Furthermore, kyphosis appears to be influenced by ethnicity, but not gender. Peoples’ thoracic sagittal curvature frequently exceeds 40°.

Trial registration

The review protocol was devised following the PRISMA-P Guidelines, and it was registered on PROSPERO (CRD42020175058) before study commencement.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02592-2.

Risk factors of dysphagia in patients with ossification of the anterior longitudinal ligament

INTRODUCTION

Cervical ossification of the anterior longitudinal ligament (OALL) occasionally leads to dysphagia by the anterior osteophyte. A recent report explained that the dysphagia after an occipito-cervical fusion is caused by the narrowing of pharyngeal space due to the cranio-cervical malalignment. The purpose of this study was to evaluate the cranio-cervical alignment in patients with OALL complaining of the dysphagia.

SUBJECTS AND METHODS

The subjects were 11 cases with complaining of dysphagia due to cervical OALL who underwent anterior cervical OALL resection and as control, age-matched 12 cases without dysphagia who have diffuse idiopathic skeletal hyperostosis in cervical spine. All subjects were male, and the mean age was 59.5 ± 9.1 years. The subjects were divided into two groups according to the symptoms of dysphagia (dysphagia, group A; control, group B). The O-C2 angle, C2-C7 angle, and the maximum thickness of OALL and the cranio-cervical alignment (pharyngeal inlet angle; PIA) and swallowing line (S-line) were measured before and after the operation on the lateral cervical radiogram at the sitting position.

RESULTS

Group A showed significantly large maximum thickness of OALL, small cervical range of motion, small O-C2 angle, large C2-C7 angle, and small PIA. The S-line crossed the anterior apex of cervical osteophyte in group A. After OALL resection, dysphagia had improved, PIA had increased, and the S-line uncrossed the apex of cervical vertebrae in all cases.

CONCLUSION

The prevalence of dysphagia in patients with cervical OALL was influenced by the thickness of osteophyte, cervical mobility, and cranio-cervical alignment.

Cervical sagittal alignment in patients with dropped head syndrome

BACKGROUND

Dropped head syndrome (DHS) can be divided into two types, the positive sagittal vertical axis (SVA) type and the negative SVA type. However, the cervical sagittal alignment of DHS including global sagittal spinal alignment and the typical cervical alignment of the types of DHS is still unclear. The purpose of this study was to clarify the character of cervical sagittal alignment of DHS and analyze the relationship between cervical sagittal alignment and global sagittal spinal alignment.

METHODS

The subjects were 35 DHS patients (10 men, 25 women, mean 71.1 years old). They were divided into two groups: negative DHS (N-DHS group, SVA < 0 mm) and positive DHS group (P-DHS group, SVA ≥ 0 mm). As control, 28 age-matched cervical spondylosis patients (CS, 21 men, 7 women, mean 67.4 years old) were analyzed. The following parameters were measured on lateral global-spine standing radiographs: cervical SVA (C2-C7SVA), O-C2A (O-C2 angle), C2 slope (C2S), C2-7A (C2-7 angle), T1 slope (T1S) and C7SVA.

RESULTS

The results of measurements of each of the averaged sagittal alignment parameters were (CS, P-DHS, N-DHS): C2-7SVA(26.2 mm, 47.3 mm, 44.5 mm), O-C2 angle (35.0°, 37.1°, 39.3°), C2S (16.5°, 31.4°, 33.8°), C2-7A (9.3°, 9.9°, -16.6°), T1S (22.9°, 39.7°, 25.7°), C7SVA (35.3 mm, 51.0 mm, -43.1 mm). C2-C7SVA and C2S were significantly larger in both types of DHS compared to CS. Comparing P-DHS with N-DHS, C2-C7A and T1S were significantly smaller in N-DHS.

CONCLUSIONS

O-C2A did not differ significantly among CS, P-DHS and N-DHS. In DHS patients, C2-7SVA and C2S were significantly larger than those of CS regardless of the type of DHS. The typical cervical sagittal alignment of DHS was different between P-DHS and N-DHS. In P-DHS, C2-7A and T1S were larger than those in N-DHS and the imbalance of thoraco-lumbar alignment should be noted.

The 3 Sagittal Morphotypes That Define the Normal Cervical Spine: A Systematic Review of the Literature and an Analysis of Asymptomatic Volunteers

BACKGROUND

Cervical alignment is vital for maintaining horizontal gaze and sagittal balance. The aims of this study were to summarize previously published descriptions of normative cervical alignment and to analyze a cohort of asymptomatic volunteers in order to identify natural clusters of normal radiographic parameters.

METHODS

We performed a systematic review of the literature on radiographic measurements of asymptomatic volunteers through a search of MEDLINE and ScienceDirect databases. We then performed an analysis of demographic and radiographic parameters of volunteers without back or neck complaints. Only subjects with a chin-brow vertical angle (CBVA) within previously published normal limits were retained for analysis. A 2-step cluster analysis was used to find natural groups of cervical alignment. Differences among groups were investigated with a post hoc analysis of variance (ANOVA).

RESULTS

We included 37 articles in our analysis. There was a broad spectrum of both C2-C7 lordosis-kyphosis and T1 slope across ages and sexes. Of the 119 asymptomatic volunteers who were available for analysis, 84 (with a mean age [and standard deviation] of 49.0 ± 17.1 years) had a CBVA ranging from -4.7° to 17.7°. The cluster analysis identified 3 alignment groups based on cervical lordosis-kyphosis and T1 slope (silhouette measure of cohesion, >0.6). Twenty-seven volunteers (32.1%) were identified as the "kyphotic curve cohort" (KCC) (mean C2-C7 Cobb angle, -8.6° ± 7.3°; mean T1 slope, 17.4° ± 6.6°), 43 volunteers (51.2%) were identified as the "medium lordosis cohort" (MLC) (mean C2-C7 Cobb angle, 8.7° ± 7.2°; mean T1 slope, 26.6° ± 4.0°), and 14 volunteers (16.7%) were identified as the "large lordosis cohort" (LLC) (mean C2-C7 Cobb angle, 21.2° ± 7.2°, mean T1 slope, 39.5° ± 6.4°) (p < 0.001 for both). Moving from KCC to LLC, there was a significant decrease in C0-C2 lordosis (p = 0.016). Examination of the cervical vertebral orientation demonstrated that C4 had a constant orientation relative to the horizontal (p = 0.665). Correlation analysis between C2-C7 and vertebral orientations again demonstrated that C4 orientation was independent of C2-C7 alignment.

CONCLUSIONS

We have identified 3 morphotypes of the cervical spine based on C2-C7 alignment and T1 slope. These findings demonstrate the broad definition of normal cervical alignment and the range of cervical lordosis-kyphosis that is acceptable.

Cervical Sagittal Alignment: Literature Review and Future Directions

Cervical alignment as a concept has come to the forefront for spine deformity research in the last decade. Studies on cervical sagittal alignment started from normative data, and expanded into correlation with global sagittal balance, prognosis of various conditions, outcomes of surgery, definition and classification of cervical deformity, and prediction of targets for ideal cervical reconstruction. Despite the recent robust research efforts, the definition of normal cervical sagittal alignment and cervical spine deformity continues to elude us. Further, many studies continue to view cervical alignment as a continuation of thoracolumbar deformity and do not take into account biomechanical features unique to the cervical spine that may influence cervical alignment, such as the importance of musculature connecting cranium-cervical-thoracic spine and upper extremities. In this article, we aim to summarize the relevant literature on cervical sagittal alignment, discuss key results, and list potential future direction for research using the '5W1H' framework; "WHO" are related?, "WHY" important?, "WHAT" to evaluate and "WHAT" is normal?, "HOW" to evaluate?, "WHEN" to apply sagittal balance?, and "WHERE" to go in the future?

Effect of cervical flexion and extension on thoracic sagittal alignment

INTRODUCTION

The cervical spine has the largest sagittal motion in the whole spine, and cervical alignment affects the thoracic sagittal alignment. However, the effects of cervical flexion and extension on thoracic sagittal alignment have not been investigated in detail. The purpose of this study was to analyze the change of thoracic sagittal alignment following cervical flexion and extension.

SUBJECTS AND METHODS

A total of 55 consecutive patients (42 men and 13 women; average age 49.1 years) who presented to our department with spinal degenerative disease between January 2016 and September 2017 were enrolled in our study. Subjects with a history of trauma, infection, tumor, inflammatory disease, ossification, or cervical deformities, and those who had undergone spinal surgery were excluded. The following parameters were analyzed: occipito-axial angle (O-C2), C2 slope (C2S), C2-C7 angle, T1 slope (T1S), thoracic kyphosis, T1-T4 angle, T5-T8 angle, T9-T12 angle, lumbar lordosis, sacral slope, pelvic tilt in cervical flexion, neutral, and extension.

RESULTS

Cervical flexion significantly decreased O-C2, C2-C7 angles and T1S, and increased C2S. Cervical extension conversely changed these parameters. At cervical flexion, the correlation of C2-C7 angle with thoracic parameters was maintained, except for the T1-T4 angle. At cervical extension, the correlation was observed with T1S and T1-T4 angle.

CONCLUSION

Cervical flexion affects the T1S and T5-T8 angle, but there is no significant change in T1-T4 and T9 and lower spino-pelvic columns. This study suggests that T2-T4 can be considered as a stable distal end when cervical long fixation for corrective surgery is performed.

Cervical sagittal alignment in adolescent high dysplastic developmental spondylolisthesis: how does the cervical spine respond to the reduction of spondylolisthesis?

Background

Although pelvic and related parameters have been well stated in lumbar developmental spondylolisthesis, cervical sagittal alignment in these patients is poorly studied, especially in high dysplastic developmental spondylolisthesis (HDDS). The purpose of this study is to investigate the sagittal alignment of the cervical spine in HDDS and how the cervical spine responds to reduction of spondylolisthesis.

Methods

Thirty-three adolescent patients with lumbar developmental spondylolisthesis who received preoperative and postoperative whole-spine x-rays were reviewed. They were divided into the HDDS group (n = 24, 13.0 ± 2.2 years old) and the low dysplastic developmental spondylolisthesis (LDDS) group (n = 9, 15.6 ± 1.9 years old). Spinal and pelvic sagittal parameters, including cervical lordosis (CL), were measured and compared between groups. In the HDDS group, the postoperative parameters were measured and compared with those before surgery.

Results

HDDS group had a higher proportion of cervical kyphosis (70.8% vs. 22.2%, P = 0.019), and there was a significant difference in CL between the two groups (− 8.5° ± 16.1° vs. 10.5° ± 11.8°, P = 0.003). CL was correlated with the Dubousset’s lumbosacral angle (Dub-LSA), pelvic tilt (PT), and thoracic kyphosis (TK). In the HDDS group, CL in patients with a kyphotic cervical spine was significantly improved after reduction of spondylolisthesis (− 16.4° ± 5.9° vs. − 3.6° ± 9.9°, P < 0.001). In the HDDS group, 46% (6/13) of the patients with postoperative Dub-LSA < 90° still had sagittal imbalance (sagittal vertical axis, [SVA] > 5 cm), while no sagittal imbalance was observed in patients with postoperative Dub-LSA > 90° (46% [6/13] vs. 0% [0/11], P = 0.016).

Conclusions

HDDS can lead to cervical kyphosis through a series of compensatory mechanisms. Reduction of spondylolisthesis and correction of lumbosacral kyphosis may correct the cervical kyphosis and normalize the overall spinal sagittal profile. Correction of Dub-LSA to above 90° might be used as an objective to better improve the sagittal alignment of the spine.

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 Spine Deformity: Indications, Considerations, and Surgical Outcomes

Cervical spinal deformity (CSD) in adult patients is a relatively uncommon yet debilitating condition with diverse etiologies and clinical manifestations. Similar to thoracolumbar deformity, CSD can be broadly divided into scoliosis and kyphosis. Severe forms of CSD can lead to pain; neurologic deterioration, including myelopathy; and cervical spine-specific symptoms such as difficulty with horizontal gaze, dysphagia, and dyspnea. Recently, an increased interest is shown in systematically studying CSD with introduction of classification schemes and treatment algorithms. Both major and minor complications after surgical intervention have been analyzed and juxtaposed to patient-reported outcomes. An ongoing effort exists to better understand the relationship between cervical and thoracolumbar spinal alignment, most importantly in the sagittal plane.

Effects of exercise programs on kyphosis and lordosis angle: A systematic review and meta-analysis

Many authors are interested in the effects that a specific exercise program could have on sagittal spinal curvatures. The purpose of this study was to determine the effects of different exercise programs on thoracic kyphosis and lumbar lordotic angle. This meta-analysis adhered to the PRISMA guideline and it was registered at PROSPERO. Five electronic databases (Pub Med, Cochrane, WOS, PEDro and EBSCO) were searched up to 31 July 2018. Eligible studies were randomized controlled trials that applied an exercise intervention and measured a kyphosis and/or lordotic angle. Study quality was performance by PEDro score. Risk of bias was assessed using the SIGN 50 checklist for randomized controlled trials. External validity was assessed using the EVAT. Ten randomized controlled trials were included for systematic review and meta-analysis. Meta-analysis with a random effect model was performed to infer the pooled estimated standardized mean difference. All studies were RCTs and they involved a total of 284 cases and 255 controls. Seven studies measured kyphosis angle. A large significant effect of the exercise on kyphosis was identified (SMD = -1.400 (95% CI-2.150 a -0.660), p = 0.000). Four studies assessed lordotic angle and moderate but not significant improvement was shown (SMD = -0.530 (95% CI-1.760 a -0.700), p = 0.401). The results suggest that exercise programs may have a positive effect on thoracic kyphosis angle, but no clear effect on lordotic angle. This systematic review suggests that strengthening rather than stretching could be more relevant for kyphosis and both qualities are important for lordosis. It is necessary to conduct more randomized controlled trials to assess the effects of strengthening and/or stretching program on kyphosis and lordotic angle and to establish the type of the exercise that is better for maintaining the sagittal disposition within normal ranges.

Factors Predicting the Surgical Risk of Osteoporotic Vertebral Compression Fractures

The aim of our study was to investigate the association between global spinal alignment, spinopelvic parameters, and outcomes of osteoporotic vertebral compression fractures (OVCF). Patients with vertebral compression fractures seen at our hospital between October 2017 and November of 2018 with a bone mineral density (BMD) T-score < -2.5 were recruited for the study. Surgical intervention was performed after eight weeks of conservative treatment depending on clinical symptoms and the willingness of patients. Spinopelvic and sagittal alignment parameters were compared between patients who had surgery and those that did not. Seventy-nine patients were included in the study. Twenty-five patients (31.6%, mean age: 73.28 ± 9.78 years) received surgery, and 54 (68.3%, mean age: 73 ± 8.58 years) conservative treatment only. Pelvic tilt, pelvic incidence, and local kyphotic angle were statistically different between the groups (all p < 0.05). A sagittal vertical axis ≥ 50 mm, distance between the C7 plumb line and the center of the fractured vertebra (DSVA) ≥ 60 mm, pelvic incidence outside of the range of 44 to 62°), and pelvic tilt ≥ 27° were associted with the need for surgical intervention. Measurement of spinopelvic parameters can predict the need for surgery in patients with OVCF.

Sagittal spinal alignment deviation in the general elderly population: a Japanese cohort survey randomly sampled from a basic resident registry

BACKGROUND CONTEXT

It is widely recognized that sagittal spinal alignment changes with age. However, there are presently no clear benchmarks for such values or those for the cervical spine in the general population. Quality epidemiological studies are needed to establish standards for spinal alignment deviation.

OBJECTIVES

In this study of an aged Japanese population, we employed random sampling from the basic resident registry of a rural town for subject selection to determine reference values of sagittal spinal alignment including the cervical spine.

STUDY DESIGN

Japanese resident cohort study based on a municipal registry.

PATIENT SAMPLE

A total of 413 aged people randomly sampled from the resident registry of a rural Japanese town.

OUTCOME MEASURES

All subjects underwent a whole spine lateral radiograph for measurement of sagittal spinal alignment parameters.

METHODS

Registered citizens of 50 to 89 years old were targeted for this survey. We established eight groups based on age (50s, 60s, 70s, and 80s) and gender (male and female) after random sampling from the resident registry of Obuse town in 2014. A total of 413 people (203 males and 210 females) were enrolled. Radiographic parameters of sagittal spinal alignment of the cohort were measured and analyzed. Funding for this study was provided by the Japan Orthopaedics and Traumatology Research Foundation (10,000 USD), the Japanese Orthopaedic Association (5,000 USD), the Japanese Society for Musculoskeletal Medicine (40,000 USD), and the Nakatomi Foundation (15,000 USD).

RESULTS

Global spinal alignments became more misaligned with age for both genders. Sagittal vertical axis (SVA) forward shift was significantly more frequent in 80s males and 70s females, and SVA in 80s females was a mean of 66 mm forward of that of 50s females. Cervical protrusion was markedly greater in 60s males onwards. In women, lumbar lordosis and posterior pelvic inclination were noticeable from a younger age than in men. The amount of pelvic tilt misalignment in female subjects was approximately 10 years earlier than their male counterparts.

CONCLUSIONS

This first resident cohort of Japanese individuals determined average spinal alignment parameters by age and gender. Spinal balance generally shifts forward as age increases. A forward shift in the upper cervical spine occurs first in men, whereas lumbopelvic alignment shift occurs first in women.

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.

Cervical Spine Deformity-Part 1: Biomechanics, Radiographic Parameters, and Classification

Cervical spine deformities can have a significant negative impact on the quality of life by causing pain, myelopathy, radiculopathy, sensorimotor deficits, as well as inability to maintain horizontal gaze in severe cases. Many different surgical options exist for operative management of cervical spine deformities. However, selecting the correct approach that ensures the optimal clinical outcome can be challenging and is often controversial. We aim to provide an overview of cervical spine deformity in a 3-part series covering topics including the biomechanics, radiographic parameters, classification, treatment algorithms, surgical techniques, clinical outcome, and complication avoidance with a review of pertinent literature.