A systematic review of the clinical effectiveness of EOS 2D/3D X-ray imaging system

Assessing radiological factors: the role of pelvic tilt in surgery for geriatric patients with degenerative spinal disorders

Background

Adult Degenerative Spinal Disorders (ADSD) pose significant clinical challenges, especially among elderly population. Currently, the decision-making process regarding surgical intervention primarily relies on the severity of clinical symptoms. However, there is no well-established standard for determining which patients are appropriate candidates for surgery. In addition, there is a noticeable lack of research focusing on the radiological assessment of patients to determine the necessity for surgical intervention. Hence, this study aims to explore potential influencing factors for surgery in terms of radiological features.

Methods

A retrospective analysis was conducted on 381 geriatric patients with ADSD. All patients underwent radiological assessments utilizing the EOS 2D/3D imaging system. We collected demographic information and a comprehensive set of 20 radiological features, including pelvic tilt (PT), sacral slope, thoracic kyphosis, pelvic incidence (PI), lumbar lordosis (LL), T1 pelvic angle, global tilt, pelvic shift, and the alignment of the C7 plumb line relative to the Center Sacral Vertical Line (CSVL). Logistic regression analysis was employed to identify risk factors associated with surgical intervention, while Restricted Cubic Spline (RCS) curve analysis was used to examine the relationship between risk factors and surgical decisions.

Results

The overall surgical intervention rate among the cohort was 29.4%. Subgroup analyses indicated that patients exhibiting higher PT (P  < 0.001), higher PI (P  = 0.007), greater PI-LL (P  = 0.001), reduced lower lumbar lordosis (P  = 0.048), elevated T1 pelvic angle (P  < 0.001), increased global tilt (P  < 0.001), and greater pelvic shift (P  = 0.025) were more likely to pursue surgical treatment. Binary logistic regression confirmed these trends, and multinomial logistic regression revealed that PT remained significantly correlated with the decision to undergo surgery (Odds Ratio [OR] = 1.085, 95% Confidence Interval [CI]: 1.028–1.146, P  = 0.003). When PT was classified into a binary variable based on the optimal threshold, patients with a PT exceeding 18.4 degree were 3.142 times (95% CI: 1.611–6.129) more likely to undergo surgery compared to those with PT at or below 18.4 degree (P  < 0.001) after adjusting for potential confounding factors. In a four-class classification, patients with PT > 18.0 degree and ≦ 25.3 degree were 3.903 times (95% CI: 1.588–9.591) more likely, while those with PT > 25.3 degree were 4.987 times (95% CI: 1.472–16.893) more likely to require surgery compared to patients with PT ≦ 11.4 degree (P  = 0.003 and P  = 0.010 respectively) after adjusting for potential confounding factors. The RCS analysis demonstrated a significant association between PT and the predicted probability of surgery after adjusting for all other variables, but no non-linear relationships were identified, indicating that the association between PT and surgery was primarily linear across the different models analyzed.

Conclusions

The findings of this study suggest that PT is a critical radiological factor associated with undergoing surgery in geriatric patients with ADSD. Higher degrees of PT significantly correlate with an increased likelihood of surgical intervention. These insights may assist clinicians in evaluating surgical options for patients with ADSD and underline the importance of radiological assessments in decision-making processes.

Trial registration

This study was registered at the Chinese Clinical Trial Registry (Registration ID: ChiCTR2400090679, retrospectively registered).

Reliability and Diagnostic Accuracy of EOS Full-Body Upright Imaging for Sarcopenia: A Retrospective Study Comparing Thigh Muscle to CT-Derived Psoas Muscle Measurements

BACKGROUND

Sarcopenia increases postoperative complication and mortality rates in elderly patients. Although measurement of the psoas muscle area on computed tomography (CT) scans is traditionally used to diagnose sarcopenia, CT is not routine in orthopaedic practice and causes unnecessary radiation exposure. EOS, a low-dose full-body imaging modality, captures musculoskeletal structures in an upright position, offering an alternative for sarcopenia diagnosis.

METHODS

Patients ≥18 years of age were included in this retrospective study if they had undergone non-contrast CT spine and EOS imaging between May 2022 and May 2024. Psoas muscle measurements at L3 and L4 were made using non-contrast CT scans, while thigh muscle measurements were obtained with EOS imaging. Inter- and intra-rater reliabilities were assessed using intraclass correlation coefficients (ICCs). Predicted probabilities for L4-psoas sarcopenia were determined through logistic regression, controlling for demographic covariates and validated with an 80% to 20% train-validate split. Sarcopenia cutoffs for anteroposterior (AP) thigh thickness and lateral (LAT) quadriceps thickness were determined with use of the Youden index.

RESULTS

Sarcopenia was identified in 23.1% of 134 patients (85 female and 49 male; 121 White, 7 Black, and 6 Hispanic) on the basis of L4-psoas muscle index thresholds. EOS and CT measurements showed excellent ICCs (≥0.90). Multivariable regressions identified AP thigh thickness and LAT quadriceps thickness as significant predictors of psoas area and L4-psoas sarcopenia. The area under the receiver operating characteristic curve for identifying L4-psoas sarcopenia was 0.85 for AP thigh thickness and 0.77 for LAT quadriceps thickness. Cutoffs were 12.47 cm (males) and 10.68 cm (females) for AP thigh thickness, and 3.23 cm (males) and 2.20 cm (females) for LAT quadriceps thickness. In the validation cohort of 27 patients, the AP thigh thickness model showed 0.94 sensitivity and 0.89 specificity, while the LAT quadriceps thickness model showed 0.70 sensitivity and 1.00 specificity. Applying these cutoffs to the entire data set showed that 66.7% of males and 75.0% of females with measurements below both cutoffs had sarcopenia.

CONCLUSIONS

EOS is a reliable alternative to CT for muscle mass assessment and sarcopenia diagnosis. EOS may be a valuable tool for assessing sarcopenia without a CT scan, as thigh muscle measurements via EOS correlate well with CT-derived psoas measurements. This imaging modality aids in early sarcopenia diagnosis, potentially enhancing preoperative planning and reducing radiation exposure, unnecessary costs, and resource utilization.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Improving Therapy for Children with Scoliosis through Reducing Ionizing Radiation by Using Alternative Imaging Methods-A Study Protocol

BACKGROUND

Patients with scoliosis often require multiple imaging modalities. The aim of this study was to find out whether primary diagnosis, including surgical planning, could be carried out entirely without computed tomography (CT) scans and whether follow-up could be replaced with alternative methods without the use of X-rays. In order to reduce the radiation exposure in the diagnosis and treatment of severe scoliosis, we expect to replace X-rays with radiation-free or less-intensive radiation examinations. This study protocol is interdisciplinary.

METHODS

A total of 50 male and female patients (children and adolescents, aged 7-18 years) treated for scoliosis will be analyzed. In addition to routine projection radiographs, preoperative CT, and/or X-ray stereoradiography (EOS) examinations, thin-slice 3D magnetic resonance imaging (MRI) sequences will be retrospectively reformatted during the preoperative MRI examination. A three-dimensional back scan (video-raster stereography) and an intraoral scan will also be obtained. The following questions should be answered at the end of the project: (1) Can MRI examination with additional thin-slice 3D reconstruction answer all relevant questions for preoperative planning instead of CT? (2) Are EOS or whole-spine X-ray examinations in combination with MRI data sufficient for the evaluation of the pedicles and spinal deformity? (3) Does the Cobb angle in the radiograph correlate with the calculations from the back scanner image and can follow-up checks be replaced? (4) Are there any correlations between dental anomalies and scoliosis?

CONCLUSIONS

Until now, pediatric patients with scoliosis have been diagnosed, monitored, and treated with numerous independent specialist disciplines, such as pediatricians, orthopedic surgeons, neurosurgeons, and general practitioners with different radiological issues. The aim of this project is to reduce radiation and lower perioperative risks by creating a preoperative and follow-up-related standard protocol in close interdisciplinary and targeted cooperation between all the specialist disciplines involved. In line with the holistic examination approach, the associated accompanying diseases and developmental disorders such as dental and neuronal malformations will also be examined. On the one hand, CT-based questions could be replaced with the reconstruction of thin-slice MRI sequences. In addition, it may be possible to use the three-dimensional back scan as an intermediate diagnostic procedure instead of X-rays in the monitoring of severe scoliosis. Insofar as correlations or causalities between scoliosis and occlusal anomalies, early orthodontic intervention could positively benefit the duration of therapy at a later stage.

DXA-derived lumbar bone strain index corrected for kyphosis is associated with vertebral fractures and trabecular bone score in acromegaly

PURPOSE

The bone strain index (BSI) is a marker of bone deformation based on a finite element analysis inferred from dual X-ray absorptiometry (DXA) scans, that has been proposed as a predictor of fractures in osteoporosis (i.e., higher BSI indicates a lower bone's resistance to loads with consequent higher risk of fractures). We aimed to investigate the association between lumbar BSI and vertebral fractures (VFs) in acromegaly.

METHODS

Twenty-three patients with acromegaly (13 males, mean age 58 years; three with active disease) were evaluated for morphometric VFs, trabecular bone score (TBS), bone mineral density (BMD) and BSI at lumbar spine, the latter being corrected for the kyphosis as measured by low-dose X-ray imaging system (EOS®-2D/3D).

RESULTS

Lumbar BSI was significantly higher in patients with VFs as compared to those without fractures (2.90 ± 1.46 vs. 1.78 ± 0.33, p = 0.041). BSI was inversely associated with TBS (rho -0.44; p = 0.034), without significant associations with BMD (p = 0.151), age (p = 0.500), BMI (p = 0.957), serum IGF-I (p = 0.889), duration of active disease (p = 0.434) and sex (p = 0.563).

CONCLUSIONS

Lumbar BSI corrected for kyphosis could be proposed as integrated parameter of spine arthropathy and osteopathy in acromegaly helping the clinicians in identifying patients with skeletal fragility possibly predisposed to VFs.

A Review of 3D Modalities Used for the Diagnosis of Scoliosis

Spine radiographs in the standing position are the recommended standard for diagnosing idiopathic scoliosis. Though the deformity exists in 3D, its diagnosis is currently carried out with the help of 2D radiographs due to the unavailability of an efficient, low-cost 3D alternative. Computed tomography (CT) and magnetic resonance imaging (MRI) are not suitable in this case, as they are obtained in the supine position. Research on 3D modelling of scoliotic spine began with multiplanar radiographs and later moved on to biplanar radiographs and finally a single radiograph. Nonetheless, modern advances in diagnostic imaging have the potential to preserve image quality and decrease radiation exposure. They include the DIERS formetric scanner system, the EOS imaging system, and ultrasonography. This review article briefly explains the technology behind each of these methods. They are compared with the standard imaging techniques. The DIERS system and ultrasonography are radiation free but have limitations with respect to the quality of the 3D model obtained. There is a need for 3D imaging technology with less or zero radiation exposure and that can produce a quality 3D model for diseases like adolescent idiopathic scoliosis. Accurate 3D models are crucial in clinical practice for diagnosis, planning surgery, patient follow-up examinations, biomechanical applications, and computer-assisted surgery.

Health technology assessment in musculoskeletal radiology: the case study of EOSedge™

OBJECTIVES

Health technology assessment (HTA) is a systematic process used to evaluate the properties and effects of healthcare technologies within their intended use context. This paper describes the adoption of HTA process to assess the adoption of the EOSedge™ system in clinical practice.

METHODS

The EOSedge™ system is a digital radiography system that delivers whole-body, high-quality 2D/3D biplanar images covering the complete set of musculoskeletal and orthopedic exams. Full HTA model was chosen using the EUnetHTA Core Model® version 3.0. The HTA Core Model organizes the information into nine domains. Information was researched and obtained by consulting the manufacturers' user manuals, scientific literature, and institutional sites for regulatory aspects.

RESULTS

All nine domains of the EUnetHTA Core Model® helped conduct the HTA of the EOSedge, including (1) description and technical characteristics of the technology; (2) health problem and current clinical practice; (3) safety; (4) clinical effectiveness; (5) organizational aspects; (6) economic evaluation; (7) impact on the patient; (8) ethical aspects; and (9) legal aspects.

CONCLUSIONS

EOS technologies may be a viable alternative to conventional radiographs. EOSedge has the same intended use and similar indications for use, technological characteristics, and operation principles as the EOS System and provides significant dose reduction factors for whole spine imaging compared to the EOS System without compromising image quality. Regarding the impact of EOS imaging on patient outcomes, most studies aim to establish technical ability without evaluating their ability to improve patient outcomes; thus, more studies on this aspect are warranted.

Reducing radiation exposure and cancer risk for children with scoliosis: EOS the new gold standard

PURPOSE

Children are exposed to significant radiation doses during the investigation and treatment phases of scoliosis. EOS is a new form of low-dose radiation scan which also yields great image quality. However, currently its use is discouraged in the UK due to higher costs. We aimed to quantify the additional radiation dose and cancer risk.

METHODS

We retrospectively reviewed all paediatric cases who received both standing whole spine roentgenograms and EOS scans as part of their investigations for scoliosis during a six-month period. We compared the radiation doses between the two modalities and estimated the additional mean lifetime cancer risk per study.

RESULTS

We identified 206 children (mean age 14.4) who met the criteria of having both scans. Dose area products (dGycm2) were converted to estimated effective doses (mSv). The total mean doses were 0.68 mSv (PA 0.49 + Lat 0.19) for plain films, and 0.13 mSv (PA 0.08 + Lat 0.04) for EOS scans (p < 0.001). Additional lifetime cancer risk of a plain film was 543% greater than EOS for both sexes (1/10727 versus 1/5827 in males, 1/34483 versus 1/6350 in females).

CONCLUSION

There is approximately 5.4-fold increase in risk of cancer for both boys and girls with roentgenograms over EOS, with girls being the most impacted. This carries a significant impact when considering the need for repeat imaging on additional lifetime malignancy risk in children. In our opinion, EOS dual planar scanning is the new gold standard when X-ray of the whole spine is required.

LEVEL OF EVIDENCE

III.

Case of the False Fracture: A Report of a Radiographic Stitching Error in a Scoliosis Patient

CASE

A 14-year-old boy with Marfan syndrome-associated scoliosis underwent postoperative imaging after scoliosis surgery. The lateral radiograph seemingly depicted a compression fracture of the L4 vertebra, despite the patient being asymptomatic. Further investigation with focused lumbar spine films, however, revealed a normal L4 vertebra. The apparent abnormality was attributed to an error in the image merging process.

CONCLUSION

Image stitching errors can lead to a false impression of structural abnormalities. It is crucial for radiology technologists and clinicians to exercise caution when reviewing digitally stitched images. We reiterate the recommendation for technicians to label stitched images and indicate overlapping regions, facilitating judicious and accurate radiographic assessment.

The Impact of Global Spinal Alignment on Standing Spinopelvic Alignment Change After Total Hip Arthroplasty

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The interactions between hip osteoarthritis (OA) and spinal malalignment are poorly understood. The purpose of this study was to assess the influence of total hip arthroplasty (THA) on standing spinopelvic alignment.

METHODS

In this retrospective cohort study, patients undergoing THA for OA with pre-and postoperative full-body radiographs were included. Standing spinopelvic parameters were measured. Contralateral hip was graded on the Kellgren-Lawrence scale. Pre-and postoperative alignment parameters were compared by paired t-test. The severity of preoperative thoracolumbar deformity was measured using TPA. Linear regression was performed to assess the impact of preoperative TPA and changes in spinal alignment. Patients were separated into low and high TPA (<20 or >/=20 deg) and change in parameters were compared between groups by t-test. Similarly, the influence of K-L grade, age, and PI were also tested.

RESULTS

95 patients were included (mean age 58.6 yrs, BMI 28.7 kg/m2, 48.2% F). Follow-up radiographs were performed at mean 220 days. Overall, the following significant changes were found from pre-to postoperative: SPT (14.2 vs. 16.1, P = 0.021), CL (-8.9 vs. -5.3, P = .001), TS-CL (18.2 vs. 20.5, P = .037) and SVA (42.6 vs. 32.1, P = .004). Preoperative TPA was significantly associated with the change in PI-LL, SVA, and TPA. High TPA patients significantly decreased SVA more than low TPA patients. There was no significant impact of contralateral hip OA, PI, or age on change in alignment parameters.

CONCLUSION

Spinopelvic alignment changes after THA, evident by a reduction in SVA. Preoperative spinal sagittal deformity impacts this change. Level of evidence: III.

Clinical application of EOS imaging system: a scoping review protocol

OBJECTIVE

The objective of this scoping review is to examine and map the existing literature on the clinical application of the EOS imaging system and to identify related evidence gaps.

INTRODUCTION

The EOS imaging system was originally developed to conduct imaging for medical conditions, such as scoliosis and anisomelia. However, recent research suggests that the modality has other clinical uses that may benefit patients via reduced radiation dose and, thus, improve patient safety.

INCLUSION CRITERIA

This scoping review will consider all quantitative study designs, including systematic reviews and meta-analyses. Imaging phantom studies and conference abstracts will be excluded.

METHODS

Databases that will be searched include Embase, MEDLINE, CINAHL Complete, Scopus, Cochrane Library, Academic Search Premier, and OpenGrey. Relevant secondary material will be identified using citation searching (backwards and forwards) of included studies through Google Scholar. In addition, we will search by author name where more than 3 included studies from the same first author are identified. Articles published from 2003 in English, Danish, Norwegian, Swedish, French, and German will be included. Two independent reviewers will perform title/abstract screening, followed by full-text screening. Data extraction will include study type and design, age of participants, anatomical/physiological region, pathology, clinical endpoint, outcome measures, sample size, and clinical application. Data will be presented in tabular format and as a narrative summary.

DETAILS OF THE REVIEW AVAILABLE AT

Open Science Framework https://osf.io/yc85j/.

The importance of thoracolumbar junctional orientation, change in thoracolumbar angle, and overcorrection of lumbar lordosis in development of proximal junctional kyphosis in adult spinal deformity surgery

OBJECTIVE

Changes in the thoracolumbar angle (TLA) would play a pivotal role in the reciprocal changes following spine realignment surgery, thereby leading to the development of proximal junctional kyphosis (PJK). This study aimed to investigate the association between TLA and the development of PJK following adult spinal deformity surgery.

METHODS

A total of 107 patients were divided into PJK+ and PJK- groups according to the development of PJK within 12 months after surgery. The TLA and spinopelvic radiological parameters were compared between the PJK+ and PJK- groups. A multivariate logistic regression model was used to identify the risk factors for PJK. The receiver operating characteristic curves of the regression models were used to investigate the cutoff values of significant parameters needed so that PJK would not occur.

RESULTS

The change in TLA (ΔTLA) in the PJK+ group was significantly larger than in the PJK- group (6.7° ± 7.9° and 2.2° ± 8.1°, respectively; p = 0.006). Multivariate logistic regression analysis demonstrated that age, postoperative pelvic incidence-lumbar lordosis, and ΔTLA were significant risk factors for PJK. The risk of developing PJK was higher when the postoperative pelvic incidence-lumbar lordosis was < 5.2 and the ΔTLA was > 3.58°.

CONCLUSIONS

The present study highlights the thinking that extensive correction of TLA and lumbar lordosis should be avoided in patients with adult spinal deformity. Overcorrection of TLA of > 3.58° could result in higher odds of PJK.

Knee Extension Is Related to the Posteriorly Deviated Gravity Line to the Pelvis in Young Adults: Radiographic Analysis Using Low-Dose Biplanar X-ray

PURPOSE

We sought to compare the radiographic parameters concerning the sagittal alignment of the standing whole-body skeletons between the knee extension group and control group using the low-dose biplanar X-ray system in a young adult population without knee pain, and to investigate the associated variables for the sagittal knee angle (sagKA) among the radiographic parameters of global sagittal alignment.

MATERIALS AND METHODS

We reviewed whole-body standing sagittal radiographs of 124 young adults taken from December 2018 to May 2020 in a single institution. We compared the radiographic parameters concerning the lower extremity sagittal alignment and global sagittal alignment between the knee extension group and control group. The factors correlated with sagKA were evaluated using multiple linear regression analysis.

RESULTS

The sagittal vertical axis (SVA), the horizontal offset between the gravity line (GL) and the posterior edge of S1 endplate (GL-S), and the horizontal offset between the GL and the hip center (GL-H) were -11.6±21.3 mm, 5.1±23.8 mm, and -25.1±27.1 mm in the knee extension group, respectively, which were significantly smaller than those in the control group. The C7 plumb line (C7PL) and GL were deviated posterior to the sacrum and the hip center in the knee extension group, with the mean sagKA of -5.6° in young adults.

CONCLUSION

The GL-H using GL, not the SVA using C7PL, was a significant radiographic factor associated with the sagKA.

Imaging in Hip Arthroplasty Management-Part 1: Templating: Past, Present and Future

Hip arthroplasty is a frequently used procedure with high success rates. Its main indications are primary or secondary advanced osteoarthritis, due to acute fracture, osteonecrosis of the femoral head, and hip dysplasia. The goals of HA are to reduce pain and restore normal hip biomechanics, allowing a return to the patient’s normal activities. To reach those goals, the size of implants must suit, and their positioning must meet, quality criteria, which can be determined by preoperative imaging. Moreover, mechanical complications can be influenced by implant size and position, and could be avoided by precise preoperative templating. Templating used to rely on standard radiographs, but recently the use of EOS^® imaging and CT has been growing, given the 3D approach provided by these methods. However, there is no consensus on the optimal imaging work-up, which may have an impact on the outcomes of the procedure. This article reviews the current principles of templating, the various imaging techniques used for it, as well as their advantages and drawbacks, and their expected results.

The influence of maturation, fitness, and hormonal indices on minutes played in elite youth soccer players: a cross-sectional study

Background

The main purpose of this study was to investigate the relationships between minutes played (MP) with maturity status, fitness, and hormonal levels, and to quantify their influence on minutes played.

Methods

Twenty-four elite youth soccer players under-16 years participated in this study, over a full-season period. Anthropometric measures, maturity status, hormonal and physical fitness levels were collected. Participants were monitored during the season. After the end-season, players were assessed in 6 different tests over a four-day period.

Results

The maximum oxygen consumption (V̇O_2max) was strongly correlated with MP (r = 0.75), maturity offset (r = 0.52), and countermovement jump (r = 0.53). Multiple linear regression explained 76% of MP (F (8, 15) = 6.05, p = 0.001), with an R2 of 0.76. Moreover, Growth hormone (GH) and V̇O_2max. were the most influential factors in MP (F (2, 21) = 17.92, p ≤ 0.001), with an R2 of 0.63.

Conclusion

High levels of GH and V̇O_2max have a preponderant role in MP by elite youth soccer players, it appears to be more pragmatic to consider other contextual dimensions, as they can impact selection for competition and minutes of participation in a match.

Associations between match participation, maturation, physical fitness, and hormonal levels in elite male soccer player U15: a prospective study with observational cohort

OBJECTIVES

The aims of this study were to analyze the relationships between minutes of play (MP) and maturity status, fitness, and hormonal levels and to explain how those measures influence the time of play.

METHODS

Twenty-six youth soccer players U15 participated in this study over a full-season period. Anthropometric measures, maturity status, growth hormone (GH), insulin-like growth factor and physical levels such as maximal oxygen uptake (VO2max), fatigue index, countermovement jump (CMJ) performance were collected. At the end-season, players were assessed in 6 different tests over four days.

RESULTS

VO2max largely correlated with GH (r = 0.57) and CMJ (r = 0.51). Also, GH largely correlated with CMJ (r = 0.55). MP had moderate correlations with VO2max (r = 0.44) and CMJ (r = 0.42). Multiple linear regression with maturation, physical fitness and hormonal levels explained R2 of 0.62 of the MP (F (8, 17) = 3.47, p = 0.015). Although each independent variable alone was not able to determine the playing time, when using the interactions, the model significantly explained the MP.

CONCLUSIONS

The combination of maturity status, physical fitness, and hormonal levels seem to play a determinant role in explaining the match participation in youth soccer players.

Exploring interactions between maturity status and playing time with fluctuations in physical fitness and hormonal markers in youth soccer players

The purpose of this study was to determine the differences in functional capacities and hormonal indices according to biological maturity and seasonal playing time status in young soccer players. Twenty-three male under-15 players (14.6 ± 0.2 years) were divided into two groups, based on their maturity status and seasonal playing time. They were measured for anthropometrics, Yo-Yo intermittent recovery level 1 (YYIR1), seven repeated sprint test (7RST), countermovement jump (CMJ), skeletal age, growth hormone, and insulin-like growth factor-1 (IGF-1) level. Age at peak height velocity (APHV) was determined to estimate the maturity timing. The results revealed that players who advanced in maturation were significantly heavier (p = 0.029) and had higher values in skeletal age (p < 0.001), sitting height (p = 0.005), CMJ (p = 0.038), and IGF-1 (p = 0.013). Players given greater playing time exhibited significantly lower fatigue index (p = 0.012), but higher CMJ (p = 0.003) and IGF-1 (p = 0.001) values. The overall results highlighted that early-maturing players and players with greater playing time obtained higher values in both CMJ and IGF-1. The findings may provide an insight on the coaches’ evaluation of players and on the possible factors that may affect the future playing status of young male soccer players.

Maturational effect on physical capacities and anabolic hormones in under-16 elite footballers: a cross-sectional study

Purpose

The purposes of this study were to describe the fitness and hormonal levels according to playing time (PT) (i.e., PT during season less (PT1) or more (PT2) than 50% of the total time) and maturation level (ML) (i.e., normal (ML1) and early maturity levels (ML2)), and to analyze the differences between groups for the measures of aerobic capacity, anaerobic power, power performance, and hormonal concentrations.

Methods

Twenty-four youth footballers of a U16 team participated in this study. Anthropometric measures, maturity status, growth hormone, insulin-like growth factor (IGF-1), maximal oxygen uptake, fatigue index, and countermovement jump were collected.

Results

Significant differences were found between both PT and ML groups for maturational status, aerobic capacity, power performance, and IGF1 concentrations. The interaction of PT and ML revealed significant differences for maturity offset and power performance. When using the skeletal age as a covariant, the previously significant differences found were reduced only to the fatigue index measure.

Conclusions

The response variables analyzed in the present study seem to be influenced by PT and ML. This must be considered when planning training, and coaches must be sensible to these effects as they may assume a preponderant role in PT.

Comparison of medial distal tibial angle in EOS imaging and weightbearing X-ray

BACKGROUND

The medial distal tibial angle (MDTA) is used for measurement of ankle alignment. Standard to measure MDTA is weightbearing mortise view. EOS imaging becomes more popular for limb alignment analysis using low-dose radiation. As MDTA might vary in EOS, comparison between both radiographic techniques has been performed.

METHODS

MDTA was compared between both techniques in 43 cases by defining the mechanical tibial axis in different ways (X-ray low, EOS low, EOS high). For each method MDTA, intra- and interobserver reliability has been compared.

RESULTS

The correlation between the different methods were measured by ICC (intraclass coefficient) and were ICC 0.86 (X-ray low/EOS low), ICC 0.85 (X-ray low/EOS high) and ICC 0.97 (EOS low/EOS high). Intra- and interobserver reliability were in each case ICC > 0.95.

CONCLUSION

ICC showed a substantial to excellent agreement between all methods. EOS is appropriate to determine MDTA and can be used for assessment of coronar deformities of the distal tibia.

Physical Functioning in Adolescents with Idiopathic Scoliosis: A Systematic Review of Outcome Measures and Their Measurement Properties

STUDY DESIGN

A systematic review.

OBJECTIVE

To summarize evidence on measurement properties of Outcome Measures (OM) used to assess physical functioning in adolescents with idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

The AIS is a common spine deformity in those aged 10 to 18 years old. Associated health problems (e.g., back pain) significantly impact the quality of life (QoL). One important domain in QoL is physical functioning, which can be measured with patient-reported outcome measures (PROM), performance-based outcome measures (PBOM), and body structure and function OM. Adequate measurement properties of OM are important for precision in research and practice.

METHODS

A two-staged search strategy was performed on electronic databases up to December 2019. Search one revealed a list of OM was used for physical functioning assessment in AIS. Search two identified studies that evaluated the measurement properties of OM in AIS; using the list identified in search one. Two independent reviewers determined study eligibility, risk of bias assessment (COnsensus-based Standards for the selection of health Measurement INstruments [COSMIN] checklist), and performed data extraction. The level of evidence was established using a modified GRADE approach.

RESULTS

Search one yielded: 28 PROM, 20 PBOM, and 10 body structure and function OM. Search two revealed: 16 measurement properties studies for PROM, one for PBOM, and three for body structure and function measures. Construct validity, reliability, and responsiveness of most PROM has been established in AIS, but not content validity or internal consistency (moderate evidence). Construct validity was sufficient for the Timed Up and Go test and body structure and function measures (very low to low evidence).

CONCLUSION

Currently, physical functioning is evaluated with a variety of measures in AIS. The majority of measurement properties studies evaluated PROM with a paucity of information on measurement properties of PBOM and body structure and function OM. Based on COSMIN methodology, none of the OM identified in this review can be recommended with confidence in individuals with AIS.Level of Evidence: 2.

Sagittal balance of the cervical spine

The treatment of adult cervical deformity continues to be complex with high complication rates. However there are many new advancements and overall patients do well following surgical correction. To date there are now many types of cervical deformity that have been classified and there exists a variety of surgical options. These recent advances have been developed in the last few years and the field continues to grow at a rapid rate. Thus, the goal of this article is to provide an updated review of cervical sagittal balance including; cervical alignment parameters, deformity classification, clinical evaluation, with both conservative and surgical treatment options.

Using Ultrasound to Screen for Scoliosis to Reduce Unnecessary Radiographic Radiation: A Prospective Diagnostic Accuracy Study on 442 Schoolchildren

Scoliosis screening is important for timely initiation of brace treatment to mitigate curve progression in skeletally immature children and adolescents. School scoliosis screening programs in Hong Kong follow the protocol of referring children screened positive with a scoliometer and Moiré topography for confirmatory standard radiography. Despite being highly sensitive (88%) in detecting those who require specialist referral, the screening program was found to have a false-positive rate >50%, which could lead to unnecessary X-ray radiation. Radiation-free ultrasound has been reported to be valid and reliable for quantitative assessment of curve severity in scoliosis patients. The aim of this prospective diagnostic accuracy study was to determine the accuracy of ultrasound in determining the threshold of referral that requires X-ray for children screened positive with the scoliometer and Moiré topography. Our study recruited 442 schoolchildren with a mean Cobb angle of 14.0 ± 6.6°. The sensitivity and specificity of ultrasound in predicting the correct referral status, confirmed by X-ray, were 92.3% and 51.6%, with positive and negative predictive values of 29.0% and 96.9%, respectively. Receiver operating characteristic curve analysis revealed area under the curve values of 0.735 for ultrasound alone and 0.832 for ultrasound in combination with measurement of angle of trunk rotation. The finding supports the accuracy of using ultrasound to determine referral status, which could result in a >50% reduction of unnecessary radiation for children undergoing scoliosis screening.

A Self-Contained 3D Biomechanical Analysis Lab for Complete Automatic Spine and Full Skeleton Assessment of Posture, Gait and Run

Quantitative functional assessment of Posture and Motion Analysis of the entire skeleton and spine is highly desirable. Nonetheless, in most studies focused on posture and movement biomechanics, the spine is only grossly depicted because of its required level of complexity. Approaches integrating pressure measurement devices with stereophotogrammetric systems have been presented in the literature, but spine biomechanics studies have rarely been linked to baropodometry. A new multi-sensor system called GOALS-E.G.G. (Global Opto-electronic Approach for Locomotion and Spine-Expert Gait Guru), integrating a fully genlock-synched baropodometric treadmill with a stereophotogrammetric device, is introduced to overcome the above-described limitations. The GOALS-EGG extends the features of a complete 3D parametric biomechanical skeleton model, developed in an original way for static 3D posture analysis, to kinematic and kinetic analysis of movement, gait and run. By integrating baropodometric data, the model allows the estimation of lower limb net-joint forces, torques and muscle power. Net forces and torques are also assessed at intervertebral levels. All the elaborations are completely automatised up to the mean behaviour extraction for both posture and cyclic-repetitive tasks, allowing the clinician/researcher to perform, per each patient, multiple postural/movement tests and compare them in a unified statistically reliable framework.

Incidental extraspinal imaging findings on adult EOS full body radiographs: prevalence and clinical importance

Purpose

The purpose of this study was to review our institutional experience with the EOS machine in order to identify the incidence and clinical significance of incidental extraspinal findings (IESF) in an adult spinal deformity population.

Methods

Our institutional database was queried for all full-length standing radiographs generated by the EOS machine. Dictations were reviewed and the number of incidental extraspinal findings were classified using a previously described system. All findings related to the spine were excluded. A subset of electronic medical records were reviewed to determine further workup for individual findings of suspected clinical significance.

Results

Original database query based on radiology reports returned a total of 1857 EOS studies. Duplicate studies, studies without the entire body, and patients with more than 1 study during the search period were excluded. 503 patient studies (55.5% female, mean age 59-years-old, range 18 to 91-years-old) met inclusion criteria. The overall rate of incidental extraspinal findings in our study was 60.4% (304 findings in 503 patients). Most findings were classified as Minor. The rate of Major and Moderate findings was 4.8%. The final rate of clinically significant incidental extraspinal findings was 0.8% and included 3 presumed metastatic lesions in long bones and 1 pulmonary nodule.

Conclusion

To our knowledge this is the first study that reports the rate of incidental extraspinal findings on full body EOS studies. We report a low rate (0.8%) of clinically significant incidental extraspinal findings which is lower than that of CT or MRI. Further research is warranted in comparing EOS and standard radiography.

Risk factors for acute proximal junctional kyphosis after adult spinal deformity surgery in preoperative motion analysis

OBJECTIVE

This study aimed to examine which motion analysis parameters regarding the dynamic aspects and/or balance affect the development acute proximal junctional kyphosis (PJK) following adult spinal deformity (ASD) surgery.

METHODS

A total of 90 consecutive patients were recruited prospectively, who underwent a corrective surgery for ASD with sagittal imbalance. According to the development of acute PJK within 6 months after surgery, the patients were divided into the PJK+ and PJK- groups. Before surgery, three-dimensional gait analyses were performed using a motion analysis system. The preoperative continuous and categorical variables were compared between the PJK+ and PJK- groups using independent t tests and chi-square tests, respectively. Finally, a multivariate logistic regression model was used to identify the risk factors and calculate the odds ratio (OR) for acute PJK.

RESULTS

A total of 20 and 70 patients were classified into the PJK+ and PJK- groups, respectively. There were no differences in the spinopelvic radiologic parameters pre- and postoperatively between the PJK+ and PJK- groups. The PJK+ group showed a significantly higher mean anterior pelvic tilt (Ant-PT) angle in preoperative motion analysis than the PJK- group (P = 0.001 for both sides). Multivariate analysis identified the mean Ant-PT angle (P = 0.047; OR 1.127; 95% CI 1.002-1.267) as a significant risk factor for acute PJK.

CONCLUSION

Preoperative Ant-PT angle during walking was associated with a higher OR in acute PJK after surgery.

Predictors of spontaneous lumbar curve correction in thoracic-only fusions: 3D analysis in AIS

PURPOSE

To evaluate how 3D parameters of the instrumented thoracic spine relate to the uninstrumented lumbar spine following thoracic-only fusion (TOF) for adolescent idiopathic scoliosis (AIS) and determine the factors predictive of lumbar correction.

METHODS

A multi-center retrospective review was conducted of AIS patients with Lenke 1-4 B or C curves undergoing fusion of their thoracic spine only with minimum 2-year follow-up and 3D spine reconstructions from biplanar radiography. Pre-operative to 2-year post-operative differences were evaluated. Pearson's correlations were used to identify 3D coronal, sagittal and axial relationships at 2 years post-operative. Multivariate linear regression was used to identify variables most predictive of lumbar curve correction.

RESULTS

Eighty-four AIS patients met inclusion (54 B modifiers, 30 C modifiers). Average pre-operative thoracic and lumbar curves were 54 ± 9° and 41 ± 7° and corrected to 19 ± 7° and 21 ± 7°, respectively. 3D T5-T12 thoracic kyphosis increased from 6 ± 13° to 26 ± 8°. Thoracic and lumbar apical rotation decreased from - 14 ± 6° to -5 ± 6° and 13 ± 5° to 11 ± 6°, respectively. Thoracic curve correction correlated with lumbar curve correction (r = 0.67, p = 0.001) and decreased LIV tilt correlated with smaller residual lumbar curve magnitude (r = 0.63, p < 0.001). Increasing 3D kyphosis of the instrumented segment correlated with increased percentage lumbar curve correction (r = 0.29, p = 0.009). Multivariate linear regression showed LIV tilt and thoracic curve magnitude as the most predictive variables of post-operative residual lumbar curve magnitude, and percent correction of the thoracic curve and change in 3D instrumented kyphosis as most predictive of percent correction of the lumbar curve.

CONCLUSIONS

Analysis of 3D data highlights several considerations for AIS patients undergoing TOF. Maximizing thoracic curve correction, leveling the LIV, and to a lesser extent, restoring kyphosis in the instrumented segment are the factors most likely to result in greater correction of the instrumented lumbar curve following thoracic-only fusions in Lenke 1-4 B and C curves.

Vertebral Fractures Associated with Spinal Sagittal Imbalance and Quality of Life in Acromegaly: A Radiographic Study with EOS 2D/3D Technology

INTRODUCTION

Acromegaly is commonly complicated by arthropathy and skeletal fragility with high risk of vertebral fractures (VFs).

OBJECTIVE

This study aimed to assess whether VFs may be associated with sagittal spine deformities, arthropathy, impaired quality of life (QoL), pain, and disability.

METHODS

Thirty-eight patients with acromegaly (median age: 55 years, 20 males) and 38 matched control subjects were evaluated by a low-dose sagittal and coronal planes, X-ray imaging system (EOS®-2D/3D) for morphometric VFs, radiological signs of spine arthropathy, and spine deformities (Cobb thoracic index ≥40°, pelvic incidence minus lumbar lordosis ≥10°, pelvic tilt >20°, and sagittal vertical axis ≥4 cm) determining sagittal spine imbalance. Acromegalic patients were also evaluated by questionnaires for QoL (Acromegaly QoL Questionnaire [AcroQoL] and Short Form-36 [SF-36]) and pain and disability (Western Ontario and McMaster University [WOMAC]).

RESULTS

Acromegalic patients showed higher prevalence of thoracic hyperkyphosis (i.e., Cobb thoracic index ≥40°; p = 0.04) and pelvic tilt >20° (p = 0.02) than control subjects. VFs were found in 34.2% of acromegalic patients (p = 0.003 vs. control subjects), in relationship with higher prevalence of hyperkyphosis (p = 0.03), pelvic tilt >20° (p = 0.04), sagittal vertical axis ≥4 cm (p = 0.03), and moderate/severe subchondral degeneration (p = 0.01). Moreover, patients with VFs had lower AcroQoL general health (p = 0.007) and SF-36 general health (p = 0.002) scores and higher WOMAC pain (p = 0.003) and global (p = 0.009) scores than patients who did not fracture.

CONCLUSIONS

In acromegaly, VFs may be associated with spine deformities and sagittal imbalance, spine arthropathy, impaired QoL, and disability.

Estimated cumulative X-ray exposure and additional cancer risk during the evaluation and treatment of scoliosis in children and young people requiring surgery

INTRODUCTION

Clinicians and patients must weigh the benefits of radiological imaging against the risks of radiation exposure in the diagnosis and treatment of scoliosis. This report aims to estimate the cumulative absorbed and equivalent dose of radiation in patients undergoing surgical treatment for scoliosis, and to present this as an estimated risk of cancer compared to background radiation levels.

METHODS

Retrospective review of estimated absorbed dose on the Computerised Radiology Information System (CRIS^®). Patients undergoing surgical correction of scoliosis (age ≤ 25) from August 2010 to August 2015 investigated. Estimated absorbed dose [milligrays (mGy)] recorded. Pedicle screws inserted using image intensification. Equivalent dose [millisieverts (mSv)] and additional cancer risk calculated from the National Research Council document 'Health risks from exposure to low levels of ionising radiation' (2006).

RESULTS

271 patients identified. Mean age 15 (range 2-25). Mean total absorbed dose 2136 mGy [standard deviation (SD) 1700 mGy]. Mean number of plain spine radiographs was 8 (SD 3) with total 1884 mGy exposure (SD 1609 mGy). Additional dose provided by CT (mean 0.17 episodes), plain chest and abdominal radiographs and image intensification. Mean number of image intensification episodes was 1.1 with mean estimated exposure 180 mGy (SD 238 mGy). Image intensification accounted for 8% of the estimated absorbed dose during treatment. Estimated mean effective dose delivered was 20.952 mSv equating to an additional cancer risk of 0.27-0.45%.

CONCLUSION

Additional cancer risk from cumulative imaging is small and equivalent to approximately 8 years of natural background radiation. Use of image intensification for pedicle screw insertion is a minor contribution (8%) to the total patient dose.

Improvement in Gait Pattern and its Relationship With Preoperative Pelvic Compensation After Surgery in Patients With Sagittal Plane Deformity

STUDY DESIGN

Prospective observational study.

OBJECTIVE

The aim of this study was to investigate the improvement in gait parameters after surgery and whether corrective surgery for sagittal imbalance would be influenced by preoperative pelvic compensation.

SUMMARY OF BACKGROUND DATA

There have been no other studies investigating the influence of preoperative pelvic compensation on surgical outcomes.

METHODS

A total of 32 patients who were scheduled to undergo corrective surgery for sagittal plane deformity were included and were followed-up for 1 year after surgery. Radiological parameters were measured on biplanar full-body imaging. Before surgery and 6 months after surgery, three-dimensional motion analyses were performed to estimate center of gravity (CoG) deviation from the center of mass (CoM), mean trunk kyphosis (TK) angle, gait deviation index (GDI), and kinematic parameters. Before surgery, the patients were classified into CoG+ and CoG- groups. "+" and "-" representing increases and decreases in the distance of CoG from CoM of the pelvic segment from first to third trials, respectively. Oswestry Disability Index (ODI) and EuroQol-5D (EQ-5D) were measured for 1 year after surgery.

RESULTS

All radiological parameters improved significantly after surgery. For gait parameters, CoG from CoM, mean TK angle, and minimum angle of the hip and knee joints in the stance phase during walking were significantly decreased after surgery and GDI scores significantly improved after surgery. The mean changes of the CoG distance from the CoG and the mean TK from first to third trials of gait analysis significantly decreased postoperatively. There were no significant differences in ODI and EQ-5D scores over 1-year follow-up assessment between CoG+ and CoG- groups.

CONCLUSION

Preoperative abnormal stooping gait, and progressive worsening of sagittal imbalance in patients with sagittal plane deformity improved after corrective surgery. Patients with preoperative dynamic sagittal imbalance could have similar surgical results to those without it after corrective surgery.

LEVEL OF EVIDENCE

3.

Degeneration of three or more lumbar discs significantly decreases lumbar spine/hip ROM ratio during position change from standing to sitting in AVN patients before THA

Background

Limitations in the lumbar spine movement reduce lumbar vertebral motion and affect spinopelvic kinematics. We studied the influence of lumbar intervertebral disc degeneration on spinofemoral movement, from standing to sitting, in patients undergoing total hip arthroplasty (THA).

Methods

Of 138 consecutive patients scheduled for THA due to unilateral avascular necrosis (AVN) of the femoral head, those with ≥3 discs with University of California at Los Angeles (UCLA) disc degeneration score > 1 were defined as the lumbar degenerative disc disease (LDD) group, and the remaining patients constituted d the control group. Full body anteroposterior and lateral EOS images in the standing and sitting positions were obtained. Pelvic incidence (PI), L1 slope (L1 s), lumbar lordosis angle (LL), pelvic tilt (PT), sacral slope (SS), femoral slope (Fs), sagittal vertical axis (SVA), hip flexion, lumbar spine flexion, and total spinofemoral flexion were measured on the images and compared between groups.

Results

No significant between-group differences were observed in the height, weight, body mass index, AVN staging, or PI, SS, and Fs on standing. The LDD group included more females and older patients, had 5° lesser LL, 5° greater PT, and larger SVA. From standing to sitting, the PI remained constant in both groups. Total spinofemoral flexion was 7° less, lumbar spine flexion 16° less, L1 slope change 6° less, and SS change 8° less, and hip flexion was 7° more in the LDD than in the control group. The spine/hip flexion ratio was significantly lower in the LDD group (0.3 versus 0.7; p < 0.001). On regression analysis, the LDD group (p < 0.001) and older age (p = 0.048) but not sex, weight, or height were significant univariate predictors of decreased spine/hip ratio.

Conclusions

Patients with LDD leant more forward and had a larger pelvis posterior tilt angle on standing and a decreased lumbar spine/hip flexion ratio, with more hip joint flexion, on sitting, to compensate for reduced lumbar spine flexion. Surgeons should be aware that elderly patients with multiple LDD have significantly different spinofemoral movements and increased risk of posterior dislocation post-THA. Preoperative patient identification, intraoperative surgical technique modification, and individualized rehabilitation protocols are necessary.

Spinopelvic Compensatory Mechanisms for Reduced Hip Motion (ROM) in the Setting of Hip Osteoarthritis

STUDY DESIGN

Retrospective review from a single institution.

OBJECTIVE

To investigate the effect of hip osteoarthritis (OA) on spinopelvic compensatory mechanisms as a result of reduced hip range of motion (ROM) between sitting and standing.

SUMMARY OF BACKGROUND DATA

Hip OA results in reduced hip ROM and contracture, causing pain during postural changes. Hip flexion contracture is known to reduce the ability to compensate for spinal deformity while standing; however, the effects of postural spinal alignment change between sitting and standing is not well understood.

METHODS

Sit-stand radiographs of patients without prior spinal fusion or hip prosthesis were evaluated. Hip OA was graded by Kellgren-Lawrence grades and divided into low-grade (LOA; grade 0-2) and severe (SOA; grade 3 or 4) groups. Radiographic parameters evaluated were pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), PI-LL, thoracic kyphosis (TK), SVA, T1-pelvic angle (TPA), T10-L2, proximal femoral shaft angle (PFSA), and hip flexion (PT change-PFSA change). Changes in sit-stand parameters were compared between LOA and SOA groups.

RESULTS

548 patients were included (LOA = 311; SOA = 237). After propensity score matching for age, body mass index, and PI, 183 LOA and 183 SOA patients were analyzed. Standing analysis demonstrated that SOA had higher SVA (31.1 vs. 21.7), lower TK (-36.2 vs. -41.1), and larger PFSA (9.1 vs. 7.4) (all p < .05). Sitting analysis demonstrated that SOA had higher PT (29.7 vs. 23.3), higher PI-LL (21.6 vs. 12.4), less LL (31.7 vs. 41.6), less TK (-33.2 vs. -38.6), and greater TPA (27.9 vs. 22.5) (all p < .05). SOA had less hip ROM from standing to sitting versus LOA (71.5 vs. 81.6) (p < .05). Therefore, SOA had more change in PT (15.2 vs. 7.3), PI-LL (20.6 vs. 13.7), LL (-21.4 vs. -13.1), and T10-L2 (-4.9 vs. -1.1) (all p < .001), allowing the femurs to change position despite reduced hip ROM. SOA had greater TPA reduction (15.1 vs. 9.6) and less PFSA change (86.7 vs. 88.8) compared with LOA (both p < .001).

CONCLUSIONS

Spinopelvic compensatory mechanisms are adapted for reduced hip joint motion associated with hip OA in standing and sitting.

LEVEL OF EVIDENCE

Level III.

Adult spinal deformity

Adult spinal deformity affects the thoracic or thoracolumbar spine throughout the ageing process. Although adolescent spinal deformities taken into adulthood are not uncommon, the most usual causes of spinal deformity in adults are iatrogenic flatback and degenerative scoliosis. Given its prevalence in the expanding portion of the global population aged older than 65 years, the disorder is of growing interest in health care. Physical examination, with a focus on gait and posture, along with radiographical assessment are primarily used and integrated with risk stratification indices to establish optimal treatment planning. Although non-operative treatment is regarded as the first-line response, surgical outcomes are considerably favourable. Global disparities exist in both the assessment and treatment of adults with spinal deformity across countries of varying incomes, which represents an area requiring further investigation. This Seminar presents evidence and knowledge that represent the evolution of data related to spinal deformity in adults over the past several decades.

Measurement of Trabecular Bone Score of the Spine by Low-Dose Imaging System (EOS®): A Feasibility Study

Purpose/Introduction: Measurement of trabecular bone score (TBS^®) of the lumbar spine on dual energy X-ray absorptiometry (DXA) devices improves fracture risk prediction. We conducted a proof of concept study to assess the feasibility of TBS^® measured on the low-dose imaging system EOS^®.

METHODS

TBS was assessed on both DXA and EOS^® in 122 patients aged ≥ 50 yr, receiving no anti-osteoporotic treatment. The TBS^® was computed on full-body EOS^® images, focusing on the lumbar spine region. The patients were also scanned with a DXA bone densitometer (Hologic) and the spine and hip bone mineral density (g/cm²) were computed.

RESULTS

TBS^® measurement on EOS^® was not possible in 34 patients due to technical problems. It could be measured on both DXA and EOS^® in 88 patients (28 with severe low-trauma fracture and 60 without fracture). TBS-EOS values were significantly lower in fractured patients compared to nonfractured patients. TBS-EOS was associated with the presence of fractures as reported by an AUC of 0.70. Odds ratio of TBS-EOS for the presence of severe low-trauma fracture was 2.00 [1.24-3.25], p = 0.005.

CONCLUSIONS

This proof of concept study, based on a prototype version of the TBS-EOS, demonstrated the feasibility of the measurement of TBS^® on low-dose EOS^® imaging devices. Results show that the TBS-EOS was lower in patients with severe low-trauma fractures compared to nonfractured patients independently from bone mineral density. Some technical issues need to be solved before its eventual use in routine clinical settings. Additional prospective studies are still needed to define the actual contribution of this new technique.

Reliability of Three-Dimensional Spinal Modeling of Patients With Idiopathic Scoliosis Using EOS System

STUDY DESIGN

Three-dimensional (3D) spinal models of children with idiopathic scoliosis (IS) were created using the EOS imaging system (EOS) and sterEOS software.

OBJECTIVE

To determine the inter- or intraobserver reproducibility of the 3D spinal models in children with IS of different apex locations.

SUMMARY OF BACKGROUND DATA

3D spinal model measurements include the Cobb angle, kyphosis, lordosis, and axial vertebral rotation (AVR). Variation of these measurements between two investigators and two different trials by the same investigator were analyzed by inter- and intraclass correlation coefficients (ICCs).

METHODS

Biplanar radiographic images of 15 patients (age: 6-15 years) with IS were uploaded into the sterEOS software. Spinal and pelvic markers were manually identified to construct a 3D spinal model and measure spinal parameters. Two trained examiners independently performed modeling and performed modeling in spaced out trials. The ICC between inter- and intraobservers were calculated.

RESULTS

ICCs between inter- and intraobservers were significant for all parameters (p < .05). Both the inter- and intraobservers showed excellent agreement for the Cobb angles in the thoracic segment, kyphosis and lordosis. Substantial interobserver agreement and excellent intraobserver agreement were determined for the Cobb angle in the thoracolumbar or lumbar (TL/L) segment, with less than 6° difference between two raters and less than 2° difference between two trials. Substantial interobserver agreement for the AVR in the TL/L region and substantial interobserver agreement for the AVR in the thoracic region were found, with less than 4° difference between raters. One rater had substantial intraobserver agreement for the AVR in the TL/L region whereas another rater reported moderate to substantial intraobserver agreement in both the thoracic and TL/L regions, with less than 3° difference between trials.

CONCLUSION

The EOS system shows reliable and repeatable results in 3D spinal modeling of children with IS.

LEVEL OF EVIDENCE

Level III.

Diagnosis of osteoporotic vertebral fractures in children

Osteoporosis is a generalised disorder of the skeleton with reduced bone density and abnormal bone architecture. It increases bone fragility and renders the individual susceptible to fractures. Fractures of the vertebrae are common osteoporotic fractures. Vertebral fractures may result in scoliosis or kyphosis and, because they may be clinically silent, it is imperative that vertebral fractures are diagnosed in children accurately and at an early stage, so the necessary medical care can be implemented. Traditionally, diagnosis of osteoporotic vertebral fractures has been from lateral spine radiographs; however, a small number of studies have shown that dual energy x-ray absorptiometry is comparable to radiographs for identifying vertebral fractures in children, while allowing reduced radiation exposure. The diagnosis of vertebral fractures from dual energy x-ray absorptiometry is termed vertebral fracture assessment. Existing scoring systems for vertebral fracture assessment in adults have been assessed for use in children, but there is no standardisation and observer reliability is variable. This literature review suggests the need for a semiautomated tool that (compared to the subjective and semiquantitative methods available) will allow more reliable and precise detection of vertebral fractures in children.

Spinal Deformity Surgery: A Critical Review of Alignment and Balance

Correction of the overall coronal and/or sagittal plane deformities is one of the main predictors of successful spinal surgery. In routine clinical practice, spinal alignment is assessed using several spinal and pelvic parameters, such as pelvic incidence and tilt, sacral slope, lumbar lordosis, thoracic kyphosis, and sagittal vertical axis. Standard values have been defined for all these parameters, and the formulas of correction have been set for determining the surgical strategy. However, several factors can potentially bias these formulas. First, all standard values are measured using conventional plain radiographs and are, therefore, prone to bias. The radiologist, measuring surgeon, and patient are possible confounding influencing factors. Second, spino-pelvic compensatory effects and biomechanically relevant structures for the patient’s posture, including ligaments, tendons, and muscles, have received minimal consideration in the literature. Therefore, even in cases of appropriately planned deformity correction surgeries, complications, revision rates, and surgical outcomes significantly vary. This study aimed to illustrate the current clinical weaknesses of the assessment of spinal alignment and the importance of holistically approaching the musculoskeletal system for any spinal deformity surgery. We believe that our detailed insights regarding spinal, sagittal, and coronal alignments as well as the considerations of an individual’s spinal balance will contribute toward improvement in routine patient care.

Radiographic Resource Utilization in the Initial Referral and Evaluation of Patients With Adolescent Idiopathic Scoliosis

INTRODUCTION

The dangers of radiation exposure in children have been well studied, with assessment of adolescent idiopathic scoliosis (AIS) documented as having the potential for notable patient exposure. The purposes of this study were to evaluate a consecutive series of patients referred to a tertiary care pediatric hospital for AIS and to assess the type and quality of imaging obtained before referral for specialist evaluation.

METHODS

We performed a prospective study of consecutive patients referred over a 6-month period to a pediatric orthopaedic practice at a large, free-standing, urban children's hospital for evaluation of AIS. We assessed prereferral radiographic exposure, evaluating the utilization and adequacy of these radiographs.

RESULTS

Of a total of 131 patients enrolled in the study, 79 had received radiographs before the visit; of these, only 59 patients (75%) brought the previously obtained radiographs to the specialist consultation, and 45 patients (76%) of this subset were found to be adequate for evaluation of AIS. Of the total cohort, 56 patients (43%) required repeat radiographs because of missing or inadequate radiographs.

DISCUSSION

We found a large number of missing or inadequate radiographs, leading to repeat radiation exposure in this cohort. Improvements in the utilization of radiographs before orthopaedic referral could decrease unnecessary patient radiation exposure.

Preliminary experience with SpineEOS, a new software for 3D planning in AIS surgery

PURPOSE

Preoperative planning of scoliosis surgery is essential in the effective treatment of spine pathology. Thus, precontoured rods have been recently developed to avoid iatrogenic sagittal misalignment and rod breakage. Some specific issues exist in adolescent idiopathic scoliosis (AIS), such as a less distal lower instrumented level, a great variability in the location of inflection point (transition from lumbar lordosis to thoracic kyphosis), and sagittal correction is limited by both bone-implant interface. Since 2007, stereoradiographic imaging system is used and allows for 3D reconstructions. Therefore, a software was developed to perform preoperative 3D surgical planning and to provide rod's shape and length. The goal of this preliminary study was to assess the feasibility, reliability, and the clinical relevance of this new software.

METHODS

Retrospective study on 47 AIS patients operated with the same surgical technique: posteromedial translation through posterior approach with lumbar screws and thoracic sublaminar bands. Pre- and postoperatively, 3D reconstructions were performed on stereoradiographic images (EOS system, Paris, France) and compared. Then, the software was used to plan the surgical correction and determine rod's shape and length. Simulated spine and rods were compared to postoperative real 3D reconstructions. 3D reconstructions and planning were performed by an independent observer.

RESULTS

3D simulations were performed on the 47 patients. No difference was found between the simulated model and the postoperative 3D reconstructions in terms of sagittal parameters. Postoperatively, 21% of LL were not within reference values. Postoperative SVA was 20 mm anterior in 2/3 of the cases. Postoperative rods were significantly longer than precontoured rods planned with the software (mean 10 mm). Inflection points were different on the rods used and the planned rods (2.3 levels on average).

CONCLUSION

In this preliminary study, the software based on 3D stereoradiography low-dose system used to plan AIS surgery seems reliable for preoperative planning and precontoured rods. It is an interesting tool to improve surgeons' practice, since 3D planning is expected to reduce complications such as iatrogenic malalignment and to help for a better understanding of the complications, choosing the location of the transitional vertebra. However, further work is needed to improve thoracic kyphosis planning. These slides can be retrieved under Electronic Supplementary Material.

Using spinopelvic parameters to estimate residual lumbar lordosis assuming previous lumbosacral fusion-a study of normative values

BACKGROUND CONTEXT

Pelvic incidence (PI)=pelvic tilt (PT)+sacral slope (SS) is an established trigonometric equation which can be expanded from studying the fixed pelvis with the spine to a fixed spinopelvic complex with the remnant spine, in scenarios of spinopelvic fusion or ankylosis. For a fixed spinopelvic complex, we propose the equation termed: lumbar incidence (LI)=lumbar tilt (LT)+lumbar slope (LS).

PURPOSE

This study aimed to establish reference values for LI, LT, and LS at each lumbar vertebral level, and to show how LI can be used to determine residual lumbar lordosis (rLL).

STUDY DESIGN

This is a cross-sectional study of prospectively collected data, conducted at a single academic tertiary health-care center.

PATIENT SAMPLE

The study included 53 healthy patients aged 19-35 with first episode mechanical low back pain for a period of <3 months. Patients with previous spinal intervention, those with known or suspected spinal pathologies, and those who were pregnant, were excluded.

OUTCOME MEASURES

Radiological measurements of LI, LT, LS, and rLL.

METHODS

All patients had full-body lateral standing radiographs obtained via a slot scanner. Basic global and regional radiographic parameters, spinopelvic parameters, and the aforementioned new parameters were measured. LI was correlated with rLL at each level by plotting LI against rLL on scatter plots and drawing lines-of-best-fit through the datapoints.

RESULTS

The mean value of L5I was 22.82°, L4I was 6.52°, L3I was -0.92°, L2I was -5.56°, and L1I was -5.95°. LI turns negative at L3, LS turns negative at the L3/L4 apex, and LT remains positive throughout the lumbar spine. We found that the relationship of LI with its corresponding rLL follows a parabolic trend. Thus, rLL can be determined from the linear equations of the tangents to the parabolic lumbar spine. We propose the LI-rLL method for determining rLL as the LI recalibrates via spinopelvic compensation post instrumentation, and thus the predicted rLL will be based on this new equilibrium, promoting restoration of harmonized lordosis. The rLL-to-LI ratio is a simplified, but less accurate, method of deriving rLL from LI.

CONCLUSIONS

This study demonstrates the extended use of PI=PT+SS proposed as LI=LT+LS. These new spinopelvic reference values help us better understand the position of each vertebra relative to the hip. In situations when lumbar vertebrae are fused or ankylosed to the sacrum to form a single spinopelvic complex, LI can be used to determine rLL, to preserve spinal harmony within the limits of compensated body balance.

Combination of whole-spine lateral radiograph and lateral scanogram in the assessment of global sagittal balance

BACKGROUND CONTEXT

Global balance of human standing is analyzed as the geometric sum of the individual alignments extending from the spinal column to the pelvis, and to the lower limbs. The innovative EOS system has opened new perspectives for the global analysis of whole-body alignment, but its use is very limited because of its high cost. An alternative may be to combine the whole-spine lateral radiograph and the lateral scanogram in the global sagittal analysis of whole-body alignment.

PURPOSE

We examined to determine the validity and reliability of a lateral scanogram in the measurement of sacropelvic parameters.

STUDY DESIGN/SETTING

A retrospective radiological study was carried out.

PATIENT SAMPLE

We randomly selected 100 sets of digital radiographs, both whole-spine radiographs and lower-limb scanograms, from our database.

OUTCOME MEASURES

Sacropelvic parameters, including pelvic incidence, sacral slope, and pelvic tilt, were measured on both whole-spine radiographs and lower-limb scanograms by three independent examiners on three separate occasions.

METHODS

Agreement regarding the measurements on both image types was calculated to assess the validity of the lateral scanogram for use in whole-body alignment determinations. Intraobserver and interobserver reliabilities among the types of measurements were calculated.

RESULTS

The sacropelvic area on the lateral scanogram was not visible in 19 patients (19%). In the remaining 81 patients, the sacropelvic parameters on the lateral scanogram were similar to those on the whole-spine lateral radiograph (Pearson correlation coefficient, 0.764-0.805). Intraobserver and interobserver reproducibilities for both modalities were good to excellent (intraclass correlation coefficient, 0.657-0.984).

CONCLUSIONS

Sacropelvic parameter measurements on lateral scanogram were reliable and were similar to those measured on whole-spine lateral radiograph. Thus, global alignment can be evaluated using the lateral scanogram in combination with the whole-spine lateral radiograph.

Radiological lumbar stenosis severity predicts worsening sagittal malalignment on full-body standing stereoradiographs

BACKGROUND CONTEXT

Patients with degenerative lumbar stenosis (DLS) adopt a forward flexed posture in an attempt to decompress neural elements. The relationship between sagittal alignment and severity of lumbar stenosis has not previously been studied.

PURPOSE

We hypothesized that patients with increasing radiological severity of lumbar stenosis will exhibit worsening sagittal alignment.

STUDY DESIGN

This is a cross-sectional study.

PATIENT SAMPLE

Our sample consists of patients who have DLS.

OUTCOME MEASURES

Standing pelvic, regional, lower extremity and global sagittal alignment, and health-related quality of life (HRQoL) were the outcome measures.

METHODS

Patients with DLS were identified from a retrospective clinical database with corresponding full-body stereoradiographs. Exclusion criteria included coronal malalignment, prior spine surgery, spondylolisthesis>Grade 1, non-degenerative spinal pathology, or skeletal immaturity. Central stenosis severity was graded on axial T2-weighted magnetic resonance imaging (MRI) from L1-S1. Foraminal stenosis and supine lordosis was graded on sagittal T1-weighted images. Standing pelvic, regional, lower extremity, and global sagittal alignment were measured using validated software. The HRQoL measures were also analyzed in relation to severity of stenosis.

RESULTS

A total of 125 patients were identified with DLS on appropriate imaging. As central stenosis grade increased, patients displayed significantly increasing standing T1 pelvic angle, pelvic tilt, sagittal vertical axis, and pelvic incidence-lumbar lordosis (p<.05). No significant difference wasfound in pelvic incidence, supine lordosis, thoracic kyphosis, or T1 spinopelvic inclination between central stenosis groups. Despite similar supine lordosis between stenosis groups, patients with Grades 2 and 3 stenosis had less standing lordosis, suggesting antalgic posturing. Upper lumbar (L1-L3) stenosis predicted worse alignment than lower lumbar (L4-S1) stenosis. Increasing severity of foraminal stenosis was associated with reduced lumbar lordosis; however, no significant postural difference in lordosis, thoracolumbar, or lower extremity compensatory mechanisms were noted between foraminal stenosis groups. Stenosis grading did not predict worsening HRQoLs in central or foraminal stenosis.

CONCLUSIONS

Severity of central lumbar stenosis as graded on MRI correlates with severity of sagittal malalignment. These findings support theories of sagittal malalignment as a compensatory mechanism for central lumbar stenosis.

Thoracolumbar Realignment Surgery Results in Simultaneous Reciprocal Changes in Lower Extremities and Cervical Spine

STUDY DESIGN

A retrospective, clinical, and radiographic single-center study.

OBJECTIVE

The aim of this study was to assess simultaneous cervical spine and lower extremity compensatory changes with changes in thoracolumbar spinal alignment.

SUMMARY OF BACKGROUND DATA

Full-body stereoradiographic imaging allows better understanding of reciprocal changes in cervical and lower extremity alignment in the setting of thoracolumbar malalignment. Few studies describe the simultaneous effect of alignment correction on these mechanisms.

METHODS

Patients aged ≥18 years undergoing instrumented thoracolumbar fusion without previous cervical spine fusion, hip, knee, or ankle arthroplasty were included. Spinopelvic, lower extremity, and cervical alignment were assessed from full-body standing stereoradiographs using validated software. Patients were matched for pelvic incidence and stratified on the basis of baseline T1-pelvic angle (TPA) as: TPA-Low <14°, TPA-Moderate = 14° to 22°, and TPA-High >22°. Perioperative changes between baseline and first postoperative visit <6 months in lower extremity alignment (pelvic shift: P Shift, sacrofemoral angle: SFA, knee angle: KA, ankle angle: AA, global sagittal axis: GSA) and cervical alignment (C0-C2 angle, C2-slope, C2-C7 lordosis and C2-C7 SVA:cSVA) were correlated with change in magnitude of TPA and sagittal vertical axis (SVA) correction.

RESULTS

After matching, 87 patients were assessed. Increasing baseline TPA severity was associated with a progressive increase in all regional spinopelvic parameters except thoracic kyphosis, in addition to increased SFA, P Shift, KA, GSA, and C2-C7 lordosis. As TPA correction increased, there was a reciprocal reduction in SFA, KA, P Shift, GSA, and C2-C7 lordosis. Change in SVA correlated most with change in GSA (r = 0.886), P Shift (r = 0.601), KA (r = 0.534), and C2-C7 lordosis (r = 0.467). Change in TPA correlated with change in SFA (r = 0.372), while SVA did not.

CONCLUSION

Patients with thoracolumbar malalignment exhibit compensatory changes in cervical spine and lower extremity simultaneously in the form of cervical hyperlordosis, pelvic shift, knee flexion, and pelvic retroversion. These compensatory mechanisms resolve reciprocally in a linear fashion following optimal surgical correction.

LEVEL OF EVIDENCE

3.

The use of magnetically-controlled growing rods to treat children with early-onset scoliosis: early radiological results in 19 children

AIMS

We undertook a prospective non-randomised radiological study to evaluate the preliminary results of using magnetically-controlled growing rods (MAGEC System, Ellipse technology) to treat children with early-onset scoliosis.

PATIENTS AND METHODS

Between January 2011 and January 2015, 19 children were treated with magnetically-controlled growing rods (MCGRs) and underwent distraction at three-monthly intervals. The mean age of our cohort was 9.1 years (4 to 14) and the mean follow-up 22.4 months (5.1 to 35.2). Of the 19 children, eight underwent conversion from traditional growing rods. Whole spine radiographs were carried out pre- and post-operatively: image intensification was used during each lengthening in the outpatient department. The measurements evaluated were Cobb angle, thoracic kyphosis, proximal junctional kyphosis and spinal growth from T1 to S1.

RESULTS

The mean pre-, post-operative and latest follow-up Cobb angles were 62° (37.4 to 95.8), 45.1° (16.6 to 96.2) and 43.2° (11.9 to 90.5), respectively (p < 0.05). The mean pre-, post-operative and latest follow-up T1-S1 lengths were 288.1 mm (223.2 to 351.7), 298.8 mm (251 to 355.7) and 331.1 mm (275 to 391.9), respectively (p < 0.05). In all, three patients developed proximal pull-out of their fixation and required revision surgery: there were no subsequent complications. There were no complications of outpatient distraction.

CONCLUSIONS

Our study shows that MCGRs provide stable correction of the deformity in early-onset scoliosis in both primary and revision procedures. They have the potential to reduce the need for multiple operations and thereby minimise the potential complications associated with traditional growing rod systems. Cite this article: Bone Joint J 2016;98-B:1240-47.

When is compensation for lumbar spinal stenosis a clinical sagittal plane deformity?

BACKGROUND CONTEXT

Degenerative lumbar stenosis (DLS) patients have been reported to lean forward in an attempt to provide neural decompression. Spinal alignment in patients with DLS may resemble that of adult spinal deformity (ASD). No previous studies have compared and contrasted the compensatory mechanisms of DLS and ASD patients.

PURPOSE

This study aimed to determine the differences in compensatory mechanisms between DLS and ASD patients with increasing severity of sagittal spinopelvic malalignment. Contrasting these compensatory mechanisms may help determine at what severity sagittal malalignment represents a clinical sagittal deformity rather than a compensation for neural compression.

STUDY DESIGN/SETTING

This is a retrospective clinical and radiological review.

PATIENT SAMPLE

Baseline x-rays in patients without spinal instrumentation, with the clinical radiological and diagnoses of DLS or ASD, were assessed for patterns of spinopelvic compensatory mechanisms. Patients were stratified by sagittal vertical axis (SVA) according to the Scoliosis Research Society-Schwab [SRS-Schwab] classification.

OUTCOME MEASURES

Radiographic spinopelvic parameters were measured in the DLS and ASD groups, including SVA, pelvic incidence-lumbar lordosis mismatch (PI-LL), T1 spinopelvic inclination (T1SPi), T1 pelvic angle (TPA), and pelvic tilt (PT).

METHODS

The two diagnosis cohorts were propensity-matched for PI and age. Each group contained 125 patients and was stratified according to the SRS-Schwab classification. Regional spinopelvic,lower limb, and global alignment parameters were assessed to identify differences in compensatory mechanisms between the two groups with differing degrees of deformity. No funding was provided by any third party in relation to carrying out this study or preparing the manuscript.

RESULTS

With mild to moderate malalignment (SRS-Schwab groups "0," or "+" for PT, PI-LL, or SVA), DLS patients permit anterior truncal inclination and recruit posterior pelvic shift instead of pelvic tilt to maintain balance, while providing relief of neurologic symptoms. Adult spinal deformity patients with mild to moderate deformity recruit pelvic tilt earlier than DLS patients. With moderate to severe malalignment, no significant difference was found in compensatory mechanisms between DLS and ASD patients.

CONCLUSIONS

Patients with DLS permit mild to moderate deformity without recruiting compensatory mechanisms of PT, reducing truncal inclination and thoracic hypokyphosis to achieve neural decompression. However, with moderate to severe deformity, their desire for upright posture overrides the desire for neural decompression, evident by the adaptation of compensatory mechanisms similar to that of ASD patients.