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IntroductionGlobal alignment analysis is of upmost importance in adult spinal deformity patients (ASD). Numerous parameters exist in the literature to measure global alignment based upon C7 or T1. One common limitation of these parameters is that they neglect the cervical segment which is essential in spinal compensatory mechanisms and in horizonta...
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Background:
To investigate the relationship between sagittal alignment and coronal deformity in patients with adolescent idiopathic scoliosis (AIS) through analysis of the spinal imaging data.
Methods:
Four hundred and fifty-four AIS patients who underwent anteroposterior and lateral radiography of the while spine were enrolled, and the spinal p...
Citations
... In these cases, postural hypervigilance may also be present, leading to increased stress in the cervical region and worsening of symptoms. 1,2 Likewise, back pain may be related to postural problems and muscle tension in the middle back region. Correct perception of sitting posture and awareness about maintaining good posture can be useful in preventing and treating this type of back pain. ...
... The spine serves as the central support structure of the body, maintaining an upright posture, mobility, and connecting various skeletal components while also protecting the spinal cord. Maintaining proper spinal alignment is essential for overall health, encompassing physical, emotional, and social well-being (Ferrero et al., 2021). Consequently, to support these activities, the curvature of the human spine is determined by lumbar lordosis (LL), thoracic kyphosis (TK), and cervical lordosis (CL) (Frederick et al., 2017;Sankey et al., 2019). ...
HEARJACK is an innovative smart jacket designed to enhance the health and well-being of military personnel. This groundbreaking project addresses the crucial need for maintaining proper posture, monitoring heart health, and managing humidity-related skin issues. Spinal alignment and posture play a fundamental role in overall well-being, and deviations from a healthy alignment can lead to various health issues. HEARJACK integrates sensors like the MPU6050 for real-time posture monitoring, DHT11 for humidity insights, and a heart rate sensor for stress assessment. These sensors, combined with an IoT algorithm, enable continuous monitoring and data analysis. The results demonstrate a significant improvement in posture, reduced skin-related health concerns, and enhanced stress management, underscoring the potential of IoT-driven wearables in military healthcare. Further research and development promise to revolutionize health and military technology
... Several studies have reported that the cervical sagittal balance is related to degenerative cervical spondylolisthesis. (Paholpak, 2017;Wang et al., 2021) lumbar pain (Arima, 2021), scoliosis (Obeid et al., 2015), pelvis position (Ferrero et al., 2021), muscle degeneration (Tamai et al., 2018), risk of postoperative sagittal spinal pelvic malalignment (Passias, 2015), global spinal alignment, and horizontal gaze (Diebo et al., 2016) and amongst others. To establish a connection between these pathologies and cervical sagittal balance, it is crucial to comprehend the effects starting from the fundamental level and progressing towards a comprehensive understanding of its biotensegric mechanism. ...
Understanding cervical sagittal balance has emerged as a crucial diagnostic criterion due to the relationship between disability, horizontalization of the gaze, and multiple neuropathologies. While numerous studies have investigated the entire cervical complex, the distinctive morphology, and biomechanics of the first two cervical vertebrae necessitate further analysis regarding weight distribution and behavior in relation to typical vertebrae. To investigate this phenomenon, we developed a morphologically simplified finite element model of the C1-C5 segment to examine the stresses and strains experienced by the cervical spine under multi-modal loading, to simulate the influence of the upper cervical region on the other cervical vertebrae spanning from C1 to C5. Our preliminary results demonstrate the effects of spine position on the distribution of stresses and strains in the intervertebral discs which may play a key role in the causation of pathological cervical balance. Emulating the superior and anterior compression, the effective stress trend was shown in the postero-superior and the deformation in C1-C2-C3 and antero-inferior for C4-C5. Based on these findings, it can be compared with various degenerative pathophysiological processes of the cervical spine. This novel approach opens up new perspectives for investigating the interplay between cervical sagittal balance and lower back pain.
... As one may see, this has implications for the development of PJK if the head is behind the hips. 36 Investigations into the relationship between L1PA and T4PA malalignment and mechanical complications are ongoing. ...
... How to achieve accurate reduction is the main research direction for the treatment. Different scholars have reported several sagittal parameters to guide surgery (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)24, 25) such as OC-C2 angle, cervicomedullary angle (CMA), clivus-canal angle (CCA), Frankfortaxial angle (FXA), and so on. ...
Objective
The objective of the study is to establish a new parameter that can be clearly measured on x-ray images to complement the description of the sagittal alignment of the craniocervical junction. The authors anticipate that this new parameter will enhance surgeons' understanding of the sagittal alignment of the craniocervical junction and play a positive role in the guidance of intraoperative reduction and in the evaluation of postoperative outcomes of patients with atlantoaxial instability.
Methods
From November 2018 to June 2020, a total of 159 asymptomatic subjects who underwent frontal and lateral cervical x-ray examination in the Second Affiliated Hospital of Soochow University were included in the study. Age, gender, previous spinal trauma, and disease history of each subject were recorded. After screening, 127 effective samples were finally obtained. When taking lateral cervical radiographs, all subjects placed their neck in a neutral position and looked straight ahead with both eyes. On the obtained lateral x-ray images, a straight line was drawn from the radix to the anterior clinoid process; another line was made along the posterior edge of the C2 vertebral body; and the angle between the two lines was measured, which was defined as the “horizontal view-axial angle.” The angle formed by the tangent of the posterior edge of the C2 vertebra and C7 vertebral body is the “C2–C7 angle,” which was used to describe the curvature of the lower cervical vertebra. The normal range of horizontal view-axial angle and its relationship with C2–7 angle were evaluated.
Results
The average C2–C7 angle of male subjects was (14.0° ± 7.4°), while that of female subjects was (11.09° ± 7.36°). The average horizontal view-axial angle of male subjects was (92.79° ± 4.52°), and that of female subjects was (94.29° ± 4.50°). Pearson correlation test showed that there was a significant negative correlation between horizontal view-axis angle and C2–C7 angle.
Conclusions
For patients with atlantoaxial instability diseases, the horizontal view-axis angle is expected to be a sagittal parameter to guide the intraoperative reduction and evaluate postoperative outcomes.
... As a result, vertebral body height (VBh) and intervertebral disk height (IVDh) were exclusively measured from magnetic resonance (MR) images because they by default contain information about pixel size [18,19,25,39]. Other specifically designed and so far rarely evaluated parameters were reported only by a few studies [29,36,37,41,44], for example, the lumbar pelvic angle (LPA) [54], pelvic incidence minus lumbar lordosis (PImLL) [55], global tilt (GT) [56], lordosis distribution index (LDI) [57], relative lumbar lordosis (rLL) [57], Barrey index [58], odontoid hip axis (OD-HA) [59], T1-pelvic angle (TPA) [60], cervical sagittal vertical axis (cSVA) [61], C2/T1/L1 slope (C2S/T1S/L1S) [62], C2/T1/ L1 incidence (C2I/T1I/L1I) [41], lumbosacral lordosis angle (LSLA) [44], sacral inclination angle (SIA) [44] and vertebral compression ratio (VCR) [63]. In this respect, Yeh et al. [37] reported the most complete set of 18 parameters, while other studies reported the measurement of 12 [41], seven [22,36], six [38], five [16,17,20,28,35] or less [12, 13, 15, 23, 24, 26, 27, 29-32, 34, 39, 40, 43-45] different parameters. ...
Purpose
To summarize and critically evaluate the existing studies for spinopelvic measurements of sagittal balance that are based on deep learning (DL).
Methods
Three databases (PubMed, WoS and Scopus) were queried for records using keywords related to DL and measurement of sagittal balance. After screening the resulting 529 records that were augmented with specific web search, 34 studies published between 2017 and 2022 were included in the final review, and evaluated from the perspective of the observed sagittal spinopelvic parameters, properties of spine image datasets, applied DL methodology and resulting measurement performance.
Results
Studies reported DL measurement of up to 18 different spinopelvic parameters, but the actual number depended on the image field of view. Image datasets were composed of lateral lumbar spine and whole spine X-rays, biplanar whole spine X-rays and lumbar spine magnetic resonance cross sections, and were increasing in size or enriched by augmentation techniques. Spinopelvic parameter measurement was approached either by landmark detection or structure segmentation, and U-Net was the most frequently applied DL architecture. The latest DL methods achieved excellent performance in terms of mean absolute error against reference manual measurements (~ 2° or ~ 1 mm).
Conclusion
Although the application of relatively complex DL architectures resulted in an improved measurement accuracy of sagittal spinopelvic parameters, future methods should focus on multi-institution and multi-observer analyses as well as uncertainty estimation and error handling implementations for integration into the clinical workflow. Further advances will enhance the predictive analytics of DL methods for spinopelvic parameter measurement.
Level of Evidence I
Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.
... While the PT and SVA are important parameters to assess segmental and postural compensatory mechanisms in ASD, these parameters do not take into account the position of the head and its impact on overall balance. Recently, a new parameter has been described to quantify global alignment that takes into account the head position; the odontoid to hip axis angle (ODHA) measures the deviation of the line joining the hip axis center to the odontoid relatively to the vertical [8]. This parameter has been shown to be of interest in understanding the compensatory mechanisms used to maintain static balance [5]. ...
Purpose
To assess dynamic postural alignment in ASD during walking using a subject-specific 3D approach.
Methods
69 ASD (51 ± 20 years, 77%F) and 62 controls (34 ± 13 years, 62%F) underwent gait analysis along with full-body biplanar Xrays and filled HRQoL questionnaires. Spinopelvic and postural parameters were computed from 3D skeletal reconstructions, including radiographic odontoid to hip axis angle (ODHA) that evaluates the head’s position over the pelvis (rODHA), in addition to rSVA and rPT. The 3D bones were then registered on each gait frame to compute the dynamic ODHA (dODHA), dSVA, and dPT. Patients with high dODHA (> mean + 1SD in controls) were classified as ASD-DU (dynamically unbalanced), otherwise as ASD-DB (dynamically balanced). Between-group comparisons and relationship between parameters were investigated.
Results
26 patients were classified as ASD-DU having an average dODHA of 10.4° (ASD-DB: 1.2°, controls: 1.7°), dSVA of 112 mm (ASD-DB: 57 mm, controls: 43 mm), and dPT of 21° (ASD-DB: 18°, controls: 14°; all p < 0.001). On static radiographs, ASD-DU group showed more severe sagittal malalignment than ASD-DB, with more altered HRQoL outcomes. The ASD-DU group had an overall abnormal walking compared to ASD-DB & controls (gait deviation index: 81 versus 93 & 97 resp., p < 0.001) showing a reduced flexion/extension range of motion at the hips and knees with a slower gait speed and shorter step length. Dynamic ODHA was correlated to HRQoL scores.
Conclusion
Dynamically unbalanced ASD had postural malalignment that persist during walking, associated with kinematic alterations in the trunk, pelvis, and lower limbs, making them more prone to falls. Dynamic-ODHA correlates better with HRQoL outcomes than dSVA and dPT.
Introduction
Our objective was to assess abnormalities of the odontoid-hip axis (OD-HA) angle in a mild scoliotic population to determine whether screening for malalignment would help predict the distinction between progressive and stable adolescent idiopathic scoliosis (AIS) at early stage.
Materials and methods
All patients (non-scoliotic and AIS) underwent a biplanar X-ray between 2013 and 2020. In AIS, inclusion criteria were Cobb angle between 10° and 25°; Risser sign lower than 3; age higher than 10 years; and no previous treatment. A 3D spine reconstruction was performed, and the OD-HA was computed automatically. A reference corridor for OD-HA values in non-scoliotic subjects was calculated as the range [5th–95th percentiles]. A severity index, helping to distinguish stable and progressive AIS, was calculated and weighted according to the OD-HA value.
Results
Eighty-three non-scoliotic and 205 AIS were included. The mean coronal and sagittal OD-HA angles in the non-scoliotic group were 0.2° and −2.5°, whereas in AIS values were 0.3° and −0.8°, respectively. For coronal and sagittal OD-HA, 27.5% and 26.8% of AIS were outside the reference corridor compared with 10.8% in non-scoliotic (OR = 3.1 and 3). Adding to the severity index a weighting factor based on coronal OD-HA, for thoracic scoliosis, improved the positive predictive value by 9% and the specificity by 13%.
Conclusion
Analysis of OD-HA suggests that AIS patients are almost three times more likely to have malalignment compared with a non-scoliotic population. Furthermore, analysis of coronal OD-HA is promising to help the clinician distinguish between stable and progressive thoracic scoliosis.
Study Design
Asymptomatic cohort: prospective, cross-sectional, multi-center. Symptomatic: retrospective, multi-surgeon, single-center.
Objective
To assess the association between cranial coronal alignment and adult spinal deformity (ASD) surgical risk and outcomes.
Summary of Background Data
ASD leads to decreased quality of life. Studies have shown that coronal malignment (CM) is associated with worse surgical outcomes.
Methods
468 adult participants were prospectively enrolled in the asymptomatic cohort. 172 symptomatic ASD patients with 2-year follow-ups were retrospectively enrolled in the symptomatic cohort. Three cranial plumb line parameters: the positions of the plumb lines from the midpoint between the medial orbital rims (ORB-L5), the odontoid (OD-L5), and the C7 centroid (C7-L5) relative to the L5 pedicle, were measured. Each subject had plumb line medial (M), touching (T), or lateral (L) to either pedicle. The association between each group of patients and radiographic parameters, intraoperative variables, patient-reported outcomes (PROs), and clinical outcomes were analyzed.
Results
In the asymptomatic cohort, OD-L5 was medial to or touching the L5 pedicle in 98.3% of volunteers. In the symptomatic patients, preoperative OD-L5-L exhibited higher mean age (56.2±14.0), odontoid-coronal vertical axis (OD-CVA) (5.5±3.3 cm), Oswestry Disability Index (ODI) score (40.6±18.4), pelvic fixation rate (56/62, 90.3%), OR time (528.4±144.6 min), median estimated blood loss (EBL) (1300cc), and durotomy rate (24/62, 38.7%). A similar pattern of higher CVA, preoperative ODI, intraoperative pelvic fixation rate, OR time, EBL, and durotomy rate was observed in ORB-L5-L and C7-L5-L patients. Final follow-up postoperative OD-L5-L was associated with higher rates of proximal junctional kyphosis (PJK) (13.0%) and pseudarthrosis (17.4%).
Conclusion
Preoperative OD-L5, ORB-L5, and C7-L5 lateral to pedicles were associated with worse preoperative ODI and higher intraoperative complexity. Postoperative OD-L5-L was associated with higher rates of PJK and pseudarthrosis. Postoperative CM, approximated by cranial plumb line lateral to the L5 pedicles, was associated with sagittal plane complications.
