Plumb Line Research Articles

A Novel All-Weather Method to Determine Deflection of the Vertical by Combining 3D Laser Tracking Free-Fall and Multi-GNSS Baselines

The bright stars in the clear night sky with weak background lights should be observed in the traditional deflection of the vertical (DOV) measurement so that the DOV cannot be observed under all-weather conditions, which limits its wide applications. An all-weather DOV measurement method combining three-dimensional (3D) laser tracking free-fall and multi-GNSS baselines is proposed in this paper. In a vacuum environment, the 3D laser tracking technique is used to continuously track and observe the motion of free-fall with high frequency and precision for obtaining 3D coordinate series. The plumb line vector equation is established to solve the gravity direction vector in the coordinate system of the laser tracker at the measuring point using least squares fitting coordinate series. Multi-GNSS observations are solved for obtaining the precise geodetic cartesian coordinates of the measuring point and GNSS baseline information. A direction transformation method based on the baseline information proposed in this paper is used to convert the gravitational direction vector in the laser tracker coordinate system into the geodetic cartesian coordinate system. The geodetic cartesian coordinates of the measuring point are used to calculate the ellipsoid normal vector, and the angle between this and the gravity direction vector in the geodetic cartesian coordinate system is estimated to obtain the astrogeodetic DOV. The DOV is projected to the meridian and prime vertical planes to obtain the meridian and prime vertical components of the DOV, respectively. The astronomical latitude and longitude of the measuring point are calculated from these two components. The simulation experiments were carried out using the proposed method, and it was found that the theoretical precision of the DOV measured by the method could reach 0.2″, which could realise all-weather observation.

P51. Which subscales of Oswestry Disability Index and Short Form 36 are related with sagittal and coronal parameters in degenerative lumbar scoliosis patients: a prospective study

<h3>BACKGROUND CONTEXT</h3> Degenerative lumbar scoliosis (DLS) patients had various degrees of disability. Previous studies have been inconclusive as to the correlation between radiographic and clinical parameters in DLS. <h3>PURPOSE</h3> The aim of this study was to identify the relationship between Oswestry Disability Index (ODI) and Short Form 36 (SF-36) total and subscale scores and global spinal parameters in DLS patients. <h3>STUDY DESIGN/SETTING</h3> A prospective study. <h3>PATIENT SAMPLE</h3> We enrolled 126 consecutive patients with degenerative de novo lumbar or thoracolumbar scoliosis patients who were referred to a tertiary hospital between August 2018 and December 2019. <h3>OUTCOME MEASURES</h3> ODI and SF-36 total and subscale scores. <h3>METHODS</h3> Sagittal (sagittal vertical axis; thoracic kyphosis; lumbar lordosis [LL]; pelvic tilt; pelvic incidence [PI]; PI-LL) and coronal (Cobb angle [CA]; coronal C7 plumb line; pelvic obliquity) parameters were measured on whole spinal radiographs. Pearson's correlation analysis was performed to reveal the relationship between parameters. <h3>RESULTS</h3> There were 76 female and 15 male patients with an average age of 70.2±8.4 years. The CA averaged 18.9±8.0°. ODI total score and SF-36 PCS had correlations with only coronal spinal parameters. ODI walking, standing, social life, and traveling domains were correlated with both coronal and sagittal parameters. Pain intensity, personal care, lifting, sitting and sex life domains were correlated with only coronal parameters. SF-36 physical function (PF) domain had correlations with both coronal and sagittal parameters. Bodily pain and vitality domains had correlations with only coronal parameters. <h3>CONCLUSIONS</h3> Only coronal parameters were correlated with ODI total score and SF-36 PCS in DLS patients. Coronal parameters were also correlated with most ODI subscales and SF-36 PF, BP and VT subscales. Although sagittal parameters were not correlated with ODI total score and SF-36 PCS, those were correlated with some subscale scores of ODI (walking, standing, social life and traveling) and SF-36 PF subscale. Analysis using subscale scores of ODI and SF-36 is helpful to understand and treat various degree of disability in DLS patients. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Deflection of Vertical Effect on Direct Georeferencing in Aerial Mobile Mapping Systems: A Case Study in Sweden

AbstractGNSS/INS applications are being developed, especially for direct georeferencing in airborne photogrammetry. Achieving accurately georeferenced products from the integration of GNSS and INS requires removing systematic errors in the mobile mapping systems. The INS sensor's uncertainty is decreasing; therefore, the influence of the deflection of verticals (DOV, the angle between the plumb line and normal to the ellipsoid) should be considered in the direct georeferencing. Otherwise, an error is imposed for calculating the exterior orientation parameters of the aerial images and aerial laser scanning. This study determines the DOV using the EGM2008 model and gravity data in Sweden. The impact of the DOVs on horizontal and vertical coordinates, considering different flight altitudes and camera field of view, is assessed. The results confirm that the calculated DOV components using the EGM2008 model are sufficiently accurate for aerial mapping system purposes except for mountainous areas because the topographic signal is not modelled correctly.

Factors Related to Preoperative Coronal Malalignment in Degenerative Lumbar Scoliosis: An Analysis on Coronal Parameters.

ObjectivesRecently the effects of coronal malalignment (CM) in degenerative lumbar scoliosis (DLS) have been reported, however, there was few studies on the correlated parameters of coronal alignments at pre‐operation. The aims of this current study were to investigate the associations of coronal parameters with scoliosis and coronal alignment, and to explore the relationships between the coronal pelvic tilt and coronal alignment in DLS.MethodsOne hundred and sixty‐one DLS patients in our hospital from May 2016 to December 2020 were reviewed and documented. The coronal balance distance (CBD, the offset between the center of C7 and the plumb line drawn from the center of S1), major Cobb (MC), fractional Cobb (FC), L4 coronal tilt, L5 coronal tilt, coronal pelvic tilt, apical rotation, and the vertebras in major curve were measured and documented. CM was considered if the CBD ≥ 30mm. All of those participants were assigned into group A (CBD ≥ 30 mm) and group B (CBD < 30 mm). Comparisons of demographic and radiographic data were performed between groups A and B. Pearson correlation and further multiple regression with stepwise method analysis were used to investigate those coronal parameters correlated to MC and CBD, respectively.ResultsThirty‐one patients suffering from CM were assigned into group A, and the rest of 130 patients were assigned to group B accordingly. Then the incidence of CM was about 19.3% (31/161). Patients in group A had less vertebras in the main curve (P = 0.009), however, the apical rotation (P < 0.001) and the L4 coronal tilt (P = 0.007) were much larger. Although the MC (P = 0.426) and FC (P = 0.06) had no difference between the two groups, the match between MC and FC was much smaller (p = 0.021) in group A. The coronal pelvic tilt correlated significantly with FC (r = 0.552, p < 0.001), but mildly with MC (r = −0.366, p < 0.001), L4 coronal tilt (r = 0.348, p < 0.001), and L5 coronal tilt (r = 0.351, p < 0.001), respectively. The CBD correlated strongly with L4 coronal tilt (r = −0.471, p < 0.001) and L5 coronal tilt (r = −0.468, p < 0.001), respectively, but mildly with FC (r = −0.255, p = 0.016). Further multiple regression analysis revealed that only L4 coronal tilt was the independent factor for MC (r 2 = 0.549, p < 0.001) and CBD (r 2 = 0.221, p < 0.001), respectively.ConclusionsThe prevalence of CM in DLS patients is about 19% at pre‐operation. With similar major Cobb, the less the vertebras in the major curve, the larger the CBD. L4 coronal tilt may correlate significantly to scoliosis and CBD. Coronal pelvic tilt may be just one of the compensations for the scoliosis deformity but effects CBD directly.

Postoperative Residual Coronal Decompensation Inhibits Self-image Improvement in Adolescent Patients with Idiopathic Scoliosis.

Retrospective cohort study. This study aimed to evaluate the relationship between C7 plumb line (C7PL) decompensation and the Scoliosis Research Society (SRS) 22-item patient questionnaire scores, including those related to self-image, preoperatively and 2 years after surgery. In the surgical treatment of adolescent idiopathic scoliosis (AIS), inferior trunk balance caused by C7PL decompensation can negatively affect patients' quality of life. However, there are few reports in the literature that describe or clarify how postoperative trunk imbalance affects each SRS-22 domain, including self-image domain scores. A total of 120 patients with AIS who underwent posterior spinal fusion from August 2006 to March 2017 at our facility and were followed up for 2 years or more were included. Radiological parameters were measured on whole-spine anteroposterior and lateral radiographs. Revised SRS-22 (SRS-22r) values were also recorded. Coronal trunk imbalance was defined as a deviation of ≥2.0 cm between the C7PL and the central sacral vertical line. Patients with and without coronal trunk imbalance at 2 years after surgery were defined as D (+) (decompensation type) and D (-), respectively. Mean SRS-22r values, including function, pain, self-image, mental health, and subtotal were compared between the D (+) and D (-) groups. Logistic regression analysis was performed to detect the preoperative factors related to D (+) using predictors, including curve type, maximum Cobb angle, and coronal trunk imbalance. At 2 years after surgery, the D (+) group had a significantly lower self-image in the domain of SRS-22r scores compared with the D (-) group. Preoperative coronal trunk imbalance was significantly related to D (+) but not to significant changes in the postoperative SRS-22 score in any of the SRS-22 domains. Postoperative C7PL deviation lowers the self-image in patients with AIS. Patients with preoperative coronal trunk imbalance were significantly more likely to be D (+).

Evaluation of Posturometric Parameters in Children and Youth Who Practice Karate: Prospective Cross-Sectional Study.

Reduced physical activity or inappropriate training can cause the development of postural abnormalities. The aim of the present study was to determine the relationship between intensive, controlled physical activity, such as karate, and postural parameters. The study group consisted of 57 young karate competitors aged 9–12 years. The control group included 76 healthy, active children in similar age. The children's posture, activity level, and time in front of electronic devices were evaluated. The following body posture assessments were carried out: Adams' test, evaluation of the plumb line, evaluation of the kyphosis, and lordosis angles using a digital inclinometer and shoulder blade position measurements using a pediscoliometer. In the majority of cases, despite evidence of an increase or decrease in the values of the plumb line and scapulae level, the results were still within the normal ranges. In 71.93% of the examined karate-training children, a decrease in torso rotation was noted. The study revealed a visible difference in postural muscle strength by the Mathiass screening test (P < 0.00001). The children in the control group spent more time in front electronic devices than the karate-training children did (P < 0.007). Postural defects regression was more often observed in the study group than in the controls (P < 10−8). The frequency of postural defects stabilization was also significantly higher in the study group than in the control children (P = 0.001). Conversely, postural defects progression was significantly more frequent in the control group than in young karate competitors (P < 10−8). These differences remained significant in subgroups of girls and boys. Physical activity performed regularly and under the direction of a professional trainer can prevent postural disorders.

Failure of Posterior Lower Lumbar/Lumbosacral Hemi-Vertebra Resection: An Analysis of Reasons and Revision Strategies.

ObjectiveTo investigate the causes of failed primary surgery and the revision strategies for congenital scoliosis (CS) patients with lower lumbar/lumbosacral (LL/LS) hemi‐vertebra (HV).MethodsFifteen CS patients with LL/LS HV (seven females and eight males) with a mean age of 20.4 ± 10.4 years undergoing revision surgery in our center were retrospectively reviewed. The radiographic parameters including Cobb angle, distance between C7 plumb line and center sacral vertical line (C7PL‐CSVL), thoracic kyphosis (TK), lumbar lordosis (LL) and sagittal vertical axis (SVA) were assessed at pre‐revision, post‐revision and the last follow‐up. The causes of failure in primary operation, and radiographic and clinical outcomes of revision procedures were analyzed.ResultsThe revision rate of patients undergoing LL/LS HV resection and correction surgery was 11.4%. The average time interval between primary surgery and revision surgery was 18.2 ± 10.6 months. The operation duration and estimated blood loss of revision surgery were 194 ± 56 min and 326 ± 74 ml, respectively. Reasons for failed primary operations were as follows: internal fixation fracture in 10 cases, curve progression in two cases, implant loose in two cases and post‐operative coronal imbalance in one case. The post‐revision Cobb angle was significantly improved from 29.9° ± 8.3° to 18.7° ± 6.7° (P < 0.001) with a correction rate of 37.5% ± 12.6%. At the final follow‐up, the average Cobb angle was 18.9° ± 6.2° and the correction was well maintained (P = 0.788). The C7PL‐CSVL at pre‐revision, post‐revision and at last follow‐up were 23.2 ± 9.3 mm, 14.8 ± 4.8 mm and 14.9 ± 5.4 mm, respectively. Significant improvements (P = 0.004) were observed after revision surgery and there was no evident loss of correction (P = 0.703). There was no significant difference in TK, LL and SVA before and after revision surgery (all P > 0.05). At the last follow‐up, no significant correction loss of above coronal and sagittal parameters were observed (all P > 0.05). The revision methods were individualized according to the primary surgical procedures and the reasons for revision. The recommended revision strategies include incision of pseudarthrosis with sufficient bone graft, fixation of satellite rods, thorough residual HV excision, prolonged fusion to S2 and transforaminal lumbar interbody fusion at lumbosacral region. Solid bony fusion and no implant‐related complication were detected during the follow‐up.ConclusionsThe causes of revision surgery for patients with congenital scoliosis (CS) due to lumbosacral HV were verified and implant failure with pseudarthrosis was the main reason for failed primary operation.

INFLUENCE OF POSITION ERRORS ON THE STABILITY OF A LOADBEARING VERTICAL ROD OF GREAT FLEXIBILITY

Many building structures are considered as rod systems. Bearing elements of rod systems are under load and experience large stresses and deformations. When external loads increase, these stresses and strains also increase. There may come a point where some elements lack strength, stiffness or stability. Such cases may arise due to uneven settlement and roll of the structure in conjunction with errors in the manufacture and installation of structures, insufficient development of projects, etc. One of the main measures for the timely prevention of emergency situations is the properly organized monitoring of the stress-strain state of the elements. In this paper, we consider a model of stressed structure, which combines elements in the form of flexible deformable rods and elements acting on them, represented by force vectors. As an example, we consider a structure of two vertical rectilinear rods pointing along one plumb line and connected in a node. The lower rod is pinched in the base and is a load bearing element. The upper rod is an external load for the lower one and is represented by the equivalent force vector. In theory, the lines of action of forces lie on one vertical line, so there are no other forces and moments besides axial longitudinal forces; the forces are applied at one point with given coordinates. When constructing the rod system, each rod must be set to a given design position. There will be position errors of the elements during the installation phase of the structure. Position errors are generally represented by errors in the specified angles of inclination of the rods and errors in the position of the ends of the rods in the assembly. In a stressed structure, these errors are equivalent to the errors of the force vectors. A modified system of force vectors arises. In such a system, due to position errors, a horizontal force arises which has the main influence on the stability of the supporting flexible rod when the external load increases.

The progression of the vertebral body bruise associated with a spinal fracture

BackgroundAdvances in magnetic resonance imaging (MRI) have made it possible to find the vertebral body bruise (VBB), which was not found in computed tomography (CT) after trauma. There has been only one study with adult patients about whether traumatic VBB will cause a collapse of the vertebral body or not. The purpose is to elucidate the progression of VBB in non-osteoporotic adult patients and to identify the possible factors influencing the progression.MethodThe VBB was defined on MRI as band-like or diffuse zones of high signal intensity on T2-weighted sequences without fracture of the cortex based on CT. The study population with traumatic VBB associated with non-osteoporotic spinal fracture was composed of 15 females and 21 males. The minimal follow-up period was 6 months. The ratio of anterior to posterior heights of the VBB, the ratio of anterior heights of the VBB to the average of those of cranial and caudal adjacent vertebral bodies, the anterior wedge angle of the VBB, and the focal angle around the VBB were compared between the initial and final visits. We evaluated the age of the patients, the C2 plumb line distance, the regional location of VBB, the etiology of VBB, and the treatment methods of the fractures as possible risk factors influencing the progression.ResultsThere was no difference in the ratios and angles between the initial and final visits. The differences in the ratios and angles between the initial and final visits were not dependent on the possible risk factors. The anterior superior area is the most common in the distribution of VBB.ConclusionsUnlike compression fractures, the vertebral body with traumatic VBB found in adult patients with non-osteoporotic spinal fractures of AO classification A or B types did not develop collapse. In clinical practice, it is reasonable to diagnose it as a spinal fracture rather than a VBB if the collapse of a possible VBB occurs.

Large Lumbar Lordosis and Coronal Deformity Angular Ratio Are Risk Factors for Adolescent Idiopathic Scoliosis in Patients With Lumbar Spondylolysis

The features of lumbar curves in patients with lumbar spondylolisthesis (LS) are unclear. The aim of this retrospective study was to present the clinical and radiologic characteristics of scoliosis due to LS and LS concurrent with main thoracolumbar/lumbar adolescent idiopathic scoliosis (AIS). This study was conducted as a single-center retrospective comparative study on 56 pediatric spondylolisthesis patients with main thoracolumbar/lumbar curves. Cases were divided into 2 groups according to the course of scoliosis after spinal surgery of LS. Sagittal spinopelvic parameters and scoliotic characteristics were compared between the 2 groups. The prevalence of scoliosis was 15.3% in pediatric LS patients in our study population. Lumbar lordosis (LL), Cobb angle, apical rotation, and coronal deformity angular ratio (C-DAR) were higher in the LS concurrent with AIS group than in the LS with functional scoliosis group (P < 0.05), while curve span, apical vertebral translation, and central sacral vertical line to C7 plumb line were lower (P < 0.05). Logistic regression analyses and receiver operating characteristic curves showed that LL and C-DAR were significant risk factors of unresolved lumbar curves after spinal surgery for LS, with a cutoff value of 51.5°and 3.5, respectively. Lumbar scoliosis may develop due to LS, or a concurrent condition to LS. LL and C-DAR are the features that differentiate AIS from functional scoliosis in patients with LS.

Prevalence of Scapulothoracic Dysfunction in Primipara after One Year of Delivery

Background: During pregnancy, there are various physiological, biomechanical, postural, and emotional changes taking place. The changes in posture which occurs during pregnancy are even maintained in postpartum period if they remain uncorrected. Due to the enlargement of breasts, size of the uterus, and mother’s weight, there is increase in lumbar and cervical lordosis and there is compensatory thoracic kyphosis, the shoulder and upper back become rounded. There is scapular protraction and internal rotation of the upper extremity; these adaptations of posture may also persist in the postpartum period due to infant care demands. Pectoralis muscles tightness and weakness of the scapular stabilizers may be pre-existing to or may occur due to pregnancy postural changes. Hence, there is a need of evaluating the upper quadrant musculoskeletal involvement during the postpartum period and its correlation with changes that occur during pregnancy. Objective: The objective of this study was to study the prevalence of scapulothoracic dysfunction in primipara after 1 year of delivery. Methods: A total 150 primipara women who had completed 1 year of delivery were randomly selected from the Krishna Institute of Medical Sciences, Karad in this analytical observational study. Scapulothoracic dysfunction was assessed using postural examination chart in the anterior, lateral and posterior views by plumb line, manual muscle testing for muscle strength, and special tests for scapular dysfunction. Results: The result showed that 71% found to be positive for scapulothoracic dysfunction through YES/NO test, respectively. Majority of the subjects (45%) had type II scapular dyskinesis, while 18% subjects had type I, 11% had type III, and 22% had type IV. On postural examination, 27% had forward head posture, 55% had protracted shoulder, and 60% had kyphotic posture. The strength test showed that 57% subjects had weak trapezius, 60% had serratus anterior weak and significant amount of weakness with gradings in the range of −3–+3 for 57% subjects in trapezius, 60% in serratus anterior, and 65% had weak rhomboid’s major with gradings in the range of −3–+3, respectively. Conclusion: The study concludes that, statistically, there was high prevalence of scapulothoracic dysfunction in primipara women after 1 year of delivery. This was due of the slouched posture that the women’s adapted due to increase in breast size, increased size of the uterus, breast feeding positioning, and also infant care which demanded hunched back posture. It was also found that women had lack of knowledge about posture.

Correlation between Postural Impairment and Lymphedema in Breast Cancer Survivors

The major complication of breast cancer is secondary lymphedema seen within few days to months after the surgery. Lymphedema has a debilitating effect on posture. The significance of this study is to show the effect of lymphedema on posture. These all have a huge impact on the quality of life of patients, within her family as well as working places. This study provides a platform to assess the spinal posture which may be at risk due to lymphedema in breast cancer survivors. Hence, the study is to find out correlation between spinal postural impairment and lymphedema in breast cancer survivors and to assess the correlation between demographic variables and lymphedema in breast cancer survivors. The aim of the study was to study and find out the correlation between postural impairment and lymphedema in breast cancer survivors. This was an observational study with the total of 116 breast cancer survivor women’s who had undergone radiotherapy and surgery were selected from Krishna Institute of Medical Sciences, Karad. Their age ranged from 35 to 60 years old. The outcome measures which were included are postural examination chart in the anterior, posterior, lateral views by plumb line, muscle length test, muscle strength test, pain assessment using visual analog scale, and lymphedema measurement using inch tape. The obtained results showed statistically high significant increase in the forward head posture, rounded shoulders, thoracic kyphosis and scoliosis, scapular dyskinesis, and increased volume of affected arm. There were high significant correlation between spinal postural impairments and lymphedema in breast cancer survivors and also correlation between demographic variables and lymphedema in breast cancer survivors.

A multi-stage ensemble network system to diagnose adolescent idiopathic scoliosis

To develop a deep learning algorithm to automatically evaluate and diagnose scoliosis on full spinal X-ray images. This retrospective study collected full spinal X-ray images (anteroposterior) from four hospital databases from January 1, 2018, to March 31, 2021. The data were divided into training and validation sets. Full spinal X-ray images for external validation were independently collected at one hospital from April 1, 2021, to June 30, 2021. Model effectiveness was validated with a public dataset. Statistical software R was used to analyze the accuracy and sensitivity of the model curvature and anatomical balance parameters and assess interrater consistency. This study included 788 and 185 training and test datasets, respectively. The accuracy and recall of the algorithm model for the Cobb angle, apical vertebrae (AV), upper vertebrae, and lower vertebrae were 89.36%, 85.71%, 77.2%, and 80.24% and 97.35%, 93.38%, 84.11%, and 87.42%, respectively. The symmetric mean absolute percentage error at the Cobb angle was 5.99%, and the automatic measurement time was 1.7 s. The mean absolute error values of the Cobb angle and the distances between the center sacral vertical line and AV and C7 plumb line were 1.07° and 1.12 and 1.38 mm, respectively. Statistical analysis confirmed that the Cobb angle results were in good agreement with the gold standard (interclass coefficients of 0.996, 0.978, and 0.825; p < 0.001). Our deep learning algorithm model had high sensitivity and accuracy for scoliosis, which could help radiologists improve their diagnostic efficiency. •Our deep learning algorithm model had high sensitivity and accuracy for scoliosis, which could help radiologistsimprove their diagnostic efficiency. • Multi-center validation data were used in this study to guarantee the reliability of the research. • Algorithmic model measures 200 times faster than radiologists.

Lateral interbody release for fused vertebrae via transpsoas approach in adult spinal deformity surgery: a preliminary report of radiographic and clinical outcomes

BackgroundLateral interbody release (LIR) via a transpsoas lateral approach is a surgical strategy to address degenerative lumbar scoliosis (DLS) patients with anterior autofusion of vertebral segments. This study aimed to characterize the clinical and radiographic outcomes of this lumbar reconstruction strategy using LIR to achieve anterior column correction.MethodsData for 21 fused vertebrae in 17 consecutive patients who underwent LIR between January 2014 and March 2020 were reviewed. Demographic and intraoperative data were recorded. Radiographic parameters were assessed preoperatively and at final follow-up, including segmental lordotic angle (SLA), segmental coronal angle (SCA), bone union rate, pelvic incidence (PI), lumbar lordosis (LL), pelvic tilt, sacral slope, PI-LL mismatch, sagittal vertical axis, Cobb angle, and deviation of the C7 plumb line from the central sacral vertical line. Clinical outcomes were evaluated using Oswestry Disability Index (ODI), visual analog scale (VAS) scores for low back and leg pain, and the short form 36 health survey questionnaire (SF-36) postoperatively and at final follow-up. Complications were also assessed.ResultsMean patient age was 70.3 ± 4.8 years and all patients were female. Average follow-up period was 28.4 ± 15.3 months. Average procedural time to perform LIR was 21.3 ± 9.7 min and was not significantly different from traditional lateral interbody fusion at other levels. Blood loss per single segment during LIR was 38.7 ± 53.2 mL. Fusion rate was 100.0% in this cohort. SLA improved significantly from − 7.6 ± 9.2 degrees preoperatively to 7.0 ± 8.8 degrees at final observation and SCA improved significantly from 19.1 ± 7.8 degrees preoperatively to 8.7 ± 5.9 degrees at final observation (P < 0.0001, and < 0.0001, respectively). All spinopelvic and coronal parameters, as well as ODI and VAS, improved significantly. Incidence of peri- and postoperative complications such as iliopsoas muscle weakness and leg numbness in patients who underwent LIR was as much as XLIF. Incidence of postoperative mechanical failure following LIR was also similar to XLIF. Reoperation rate was 11.8%. However, there were no reoperations associated with LIR segments.ConclusionsThe LIR technique for anterior column realignment of fused vertebrae in the context of severe ASD may be an option of a safe and effective surgical strategy.

The relationship of hip loading asymmetry and radiological parameters of the spine in Lenke type 1 idiopathic scoliosis

BackgroundIdiopathic scoliosis does not only cause structural changes in the spine, but also functional changes of the musculoskeletal system. Research questionDoes idiopathic scoliosis lead to asymmetric hip loading in severe Lenke type 1 deformity? Methods23 patients (18 girls, 5 boys) aged 15 ± 2.8 years with an adolescent idiopathic main thoracic curve (Cobb angle 48.8°+/- 9.2°) were included. Measured X-ray parameters were: Cobb angle of primary thoracic and secondary lumbar curve, translation of the C7- plumb line, apical thoracic vertebra and apical lumbar vertebra from the central sacral vertical line. Subjects were examined by means of kinematic and kinetic gait analysis. The symmetry index (SI) was calculated as a ratio of hip frontal moments during a single stance for both sides when the symmetrical load was considered SI = 0 + /- 29.36 (0 +/- 1 SD of the mean SI of the healthy population). The Pearson correlation coefficient was used to show the relation between hip loading and radiologic measures of spinal deformity. ResultsOnly 34.8% of subjects with Lenke type 1 deformity showed symmetrical hip loading. Significant negative correlation was proved between SI and apical thoracic vertebra translation (R = - 0541; p < 0,05) as well as between SI and coronal imbalance (R = −0,5197; p < 0,05). There was no correlation between SI and the magnitude of the primary thoracic curve (R = −0.19; p = 0.385). Coronal imbalance correlates positively with translation of apical thoracic vertebra (R = 0,7255; p < 0,05). SignificanceTwo-thirds of subjects with Lenke type 1 deformity showed asymmetrical hip loading. This asymmetry is related to the translation of the apical thoracic vertebra and coronal imbalance and is not related to the magnitude of the main thoracic curve. On the contrary, the secondary lumbar curve plays role in the compensatory mechanism of the trunk.

Wonder Woman

Wonder Woman Constance Adler (bio) There is a scar in the center of my chest. A whitish and shiny round patch, the size of a silver dollar, the scar does not match the surrounding skin. It does not blend with its environment; it cannot not hide. Located just above what we might generously refer to as my "cleavage," this scar marks the place where a hard pad pressed into my skin for the months that I wore a back brace, known as the Milwaukee brace, when I was fourteen years old. Here is a picture of the brace: Imagine a contraption that clasped my head in a metal loop, secured tight against my chin and the back of my skull. Metal posts connected the head restraint to a hard, plastic girdle that encased my pelvis and was locked shut at the back with straps, so tight that it left deep-red indentations in the soft flesh of my backside. Once in place, the whole thing resembled a medieval instrument of torture. I came to think of it as a cage that I carried around with me all the time. It was hideous, and it made me hideous. While I was in the brace, it was impossible for me to move from hips to head. The cage held me in a rock-rigid grasp. I could not sleep curled up in a protective knot, as was my habit, but had to lie on my back like a corpse on a slab. I could not bend or turn side to side or look up or down. I could walk, but it was difficult to eat or talk because my chin kept hitting the metal loop around my head when I opened my mouth. I could not tip [End Page 111] my head to look down to the food on the plate in front of me and had to guess at what I might be forking into my mouth. I could go to school, and spend time with my friends, but I was always caged. I had to wear extra-large clothes to fit over the brace, and its hard unsightly lumps protruded through my clothes instead of the normal soft form of my girl's body. I could not see my own feet or reach down to tie my own shoelaces. If my shoe came untied at school, I had to ask a friend to tie it for me. Some kids asked if I'd been mangled in a car accident. The clinical purpose of the Milwaukee brace was to maintain my girl's body in this unyielding position for a year until my back and shoulders grew accustomed to a center plumb line. Then I'd be released, ideally as a more perfect girl. One day I'll have to find out why Milwaukee gets credit for this instrument of torture. What I can tell you now is that my parents put me into this brace for reasons that were a complete mystery to me. They had threatened me with a back brace if I didn't stand up straight, a threat that I did not take seriously. At the dinner table, my father enforced the posture requirement by hitting the back of my head. Slouching made me ugly, apparently, or less than perfect, which for a girl was a moral stain. But I wasn't paying much attention to threats or perfection. I was a dreamy, distracted child with other things on my mind, far more interesting than my posture. This private realm of my imagination also offered an escape from beatings, so I went there often. When I failed to be mindful of my posture, my parents followed through on the threat. My mother and father presented this back brace to me as a punishment for my willful disobedience. This sounds crazy, I know. Why would anyone do that to their kid just to win a power game? But that was thrust of their argument at the time. My mother was in charge of bringing me to the DuPont Orthopedic Clinic in Delaware. During the course of fitting me for the brace, one of the doctors took photographs of...

Neurological complications after three-column osteotomy in spinal deformity patients with different magnetic resonance imaging -based classification of spinal cord shape

Objective: To compare the incidences of neurological complications after three-column osteotomy based on the magnetic resonance imaging(MRI)-based classification of spinal cord shape and cerebrospinal fluid in patients with severe thoracic kyphoscoliosis. Methods: A total of 112 patients (52 males, 60 females, age (M(Q1,Q3)) 13.5 years (9.0-38.5 years)) with thoracic kyphoscoliosis who underwent three-column osteotomy in Nanjing Drum Tower Hospital from August 2015 to August 2018 were retrospectively analyzed. The radiographic parameters including spinal cord morphology at apex, Cobb angle of main curve, distance between C7 plumb line and center sacral vertical line (C7PL-CSVL), global kyphosis (GK) and sagittal vertical axis (SVA) were measured, retrospectively. The Frankel scoring system was used for the evaluation of neurological status at pre-operation, post-operation and the last follow-up. Results: The spinal cord morphologies at apex were classified into type Ⅰ in 8 (7.1%) patients, type Ⅱ in 58 (51.8%), and type Ⅲ in 46 (41.1%), respectively. The patients were followed-up for (28.5±3.4) months. Compared with pre-operation, the Cobb angle of main curve, C7PL-CSVL, GK and SVA showed significantly improvement at post-operation (all P<0.05) and with no significant correction loss at the last follow-up (all P>0.05). New neurological complications were detected in 3 patients with type Ⅱ spinal cord shape, of whom the neurological scores were Frankel D at post-operation. For patients with type Ⅲ spinal cord shape, new neurological complications were detected in 6 patients including 1 Frankel C and 5 Frankel D. In addition, deterioration of neurological status from Frankel D to Frankel C was found in 3 patients with type Ⅲ spinal cord shape. The incidence of new or deteriorating neurological complications in patients with type Ⅲ spinal cord shape was higher than that in type Ⅱ patients (19.6% vs 5.2%, P=0.037). Conclusions: The MRI-based classification is associated with post-operative neurological complications in patients with severe kyphoscoliosis undergoing three-column osteotomy. Patients with type Ⅲ spinal cord shape are at higher risk of post-operative neurological complications.

The Impact of Spinopelvic Parameters on Hip Degeneration After Spinal Fusion.

Retrospective cohort study. This study aimed to investigate the effects of spinopelvic alignment parameters after spinal fusion on the rate of joint space narrowing in nonarthritic hips. Spinal fusion affects the forces on the adjacent hip joint. Therefore, hip joint narrowing may be increased after spinal fusion surgery. However, the relationship between spinal alignment and hip degeneration remains unclarified. We retrospectively reviewed data from patients who underwent lumbar spinal fusion from 2011 to 2018 at our institute. Patients with hip osteoarthritis (Kellgren-Lawrence grade ≥II) or hip dysplasia were excluded. The rate of hip joint space narrowing after spinal fusion was measured in 191 patients (382 hips). We assessed the effects of the following spinopelvic alignment parameters on the joint narrowing rate: pelvic tilt, sacral slope (SS), pelvic incidence (PI), lumbar lordosis (LL), PI-LL, sagittal vertical axis, and distance between the C7 plumb line, and the central sacral vertical line (C7-CSVL). The hip joint narrowing rate was greater when four or more levels were fused compared with single-level fusion. After adjusting for the effects of patient-related factors, the alignment parameters significantly associated with the hip joint narrowing rate were the PI ( P = 0.0002), SS ( P = 0.047), and PI-LL ( P = 0.0022). A subgroup analysis of patients who underwent long fusion (four or more levels combined with iliac screws) also indicated that the PI ( P = 0.013), SS ( P = 0.0054), and PI-LL ( P = 0.046) were associated with the hip joint narrowing rate. The PI, SS, and PI-LL were associated with the progression of hip joint narrowing after spinal fusion, especially after fusion of four or more levels. Surgeons need to be aware of the risk of increased hip joint narrowing in patients with a large PI, SS, and PI-LL after fusion surgery.

The Effect of Head and Neck Stabilization Exercises on Dynamic Balance in the Elderly With Forward Head Posture

Introduction: This study aimed to investigate the effect of head and neck stabilization exercises on improving balance in older adults with forward head posture. Materials and Methods: Thirty elderly participants with forward head posture and Mean±SD age of 65.7±5.2 years were examined. The forward head posture was measured by plumb line and craniovertebral angle. Elderly balance was evaluated before and after 8 weeks of head and neck stabilization exercises with Timed Up and Go (TUG) and Functional Reach (FR) tests. The paired t-test was used to examine the changes that occurred after the intervention. Results: The results showed that head and neck stabilization exercises in the elderly significantly changed TUG test (8.3 s before the intervention, 7.8 s after the intervention; P=0.03) and FR test (23.4 cm before the intervention, 24.7 cm after the intervention; P=0.01) omitted. No significant statistical changes were observed in the amount of the craniovertebral angle after the intervention. Conclusion: Based on the study results, performing the head and neck stabilization exercises did not cause significant changes in the craniovertebral angle but improved the dynamic balance of the elderly.

Multiple-rod constructs and use of bone morphogenetic protein-2 in relation to lower rod fracture rates in 141 patients with adult spinal deformity who underwent lumbar pedicle subtraction osteotomy.

The purpose of this study was to compare rod fracture (RF) rates among three types of rod constructs (RCs) following lumbar pedicle subtraction osteotomy (PSO) for adult spinal deformity (ASD). A retrospective review of consecutive patients with adult spinal deformity who were treated with lumbar PSO between 2007 and 2017 was performed. The minimum follow-up was 2 years. Three RCs were compared: standard (2 main rods), satellite (2 main rods with satellite rod), and nested (2 main rods and 2 short rods spanning osteotomy). Outcomes examined included RF rate, time to RF, pseudarthrosis, and reoperation. Multivariate analysis was used. A total of 141 patients were included 55 with standard, 23 with satellite, and 63 with nested RCs. The mean age was 65.2 years and 34.8% of patients were male. Radiographic preoperative and postoperative results were as follows: sagittal vertical axis (11.0 vs 3.9 cm), lumbar lordosis (28.5° vs 57.1°), pelvic tilt (30.6° vs 21.0°), pelvic incidence (61.5° vs 60.0°), distance between central sacral vertical line and C7 plumb line (2.2 vs 1.5 cm), and scoliosis (18.9° vs 11.3°). The average time to RF was 12.4 months. Overall RF, bilateral RF, pseudarthrosis, and reoperation rates were 22.7%, 5.0%, 20.6%, and 17.7%, respectively. Standard RCs had a significantly higher RF (36.4% vs 13.0% vs 14.3%, p = 0.008), bilateral RF (35.0% vs 0.0% vs 0.0%, p = 0.021), pseudarthrosis (34.5% vs 8.7% vs 12.7%, p = 0.004), and reoperation (30.9% vs 4.3% vs 11.1%, p = 0.004) rates. Satellite RCs (OR 0.21, p = 0.015), nested RCs (OR 0.24, p = 0.003), and bone morphogenetic protein-2 (OR 0.28, p = 0.005) were independently associated with lower odds of RF. Use of multiple rods in the satellite RC and nested RC groups was associated with lower rates of RF, pseudarthrosis, and reoperations following lumbar PSO. Bone morphogenetic protein-2 was associated with a reduction in RF rate as well.