Neck-shaft angle measurement in children: accuracy of the conventional radiography-based (2D) methods compared to 3D reconstructions.

Aim of this study was to examine the accuracy of widely used conventional radiography-based (2D) neck-shaft angle measurements compared to 3D reconstruction. In our retrospective study, EOS 2D/3D images of 156 patients (312 limbs) were selected from our database (4-16 years old: 6 girls and 6 boys/year), where no pathology was revealed. Using the 2D modality of the EOS method neck-shaft angle was measured using the "biggest diameter" and "circle fitting" techniques to define the femoral neck axis and 1/3, 1/2 and full femur to determine the femoral shaft axis. EOS 3D reconstructions of same images were also performed and a comparison of 2D and 3D results was made. We did not find any significant difference between accuracy of the four examined 2D methods, although the deviation between 2 and 3D results was considerable (average difference: 5.11-5.58°, p < 0,001). In 31% of the cases, difference was more than 10°. Only femoral torsion showed significant influence on the difference (correlation coefficient: 0.380, p < 0.001). We did not find a clinically significant difference between the examined 2D methods, although their accuracy was highly questionable compared to 3D results. We suggest using any 3D imaging method for surgical planning and in uncertain cases.

Evaluation and Comparison of Traditional Plaster and Fiberglass Casts with 3D-Printed PLA and PLA-CaCO3 Composite Splints for Bone-Fracture Management.

Bone fractures pose a serious challenge for the healthcare system worldwide. A total of 17.5% of these fractures occur in the distal radius. Traditional cast materials commonly used for treatment have certain disadvantages, including a lack of mechanical and water resistance, poor hygiene, and odors. Three-dimensional printing is a dynamically developing technology which can potentially replace the traditional casts. The aim of the study was to examine and compare the traditional materials (plaster cast and fiberglass cast) with Polylactic Acid (PLA) and PLA-CaCO3 composite materials printed using Fused Filament Fabrication (FFF) technology and to produce a usable cast of each material. The materials were characterized by tensile, flexural, Charpy impact, Shore D hardness, flexural fatigue, and variable load cyclic tests, as well as an absorbed water test. In addition, cost-effectiveness was evaluated and compared. The measured values for tensile strength and flexural strength decreased with the increase in CaCO3 concentration. In the fatigue tests, the plaster cast and the fiberglass cast did not show normal fatigue curves; only the 3D-printed materials did so. Variable load cyclic tests showed that traditional casts cannot hold the same load at the same deflection after a higher load has been used. During these tests, the plaster cast had the biggest relative change (-79.7%), compared with -4.8 % for the 3D-printed materials. The results clearly showed that 3D-printed materials perform better in both static and dynamic mechanical tests; therefore, 3D printing could be a good alternative to customized splints and casts in the near future.

Alternative methods for skeletal maturity estimation with the EOS scanner-Experience from 934 patients.

BACKGROUND: Hand-wrist bone age assessment methods are not possible on typical EOS 2D/3D images without body position modifications that may affect spinal position. We aimed to identify and assess lesser known bone age assessment alternatives that may be applied retrospectively and without the need for extra imaging. MATERIALS AND METHODS: After review of 2857 articles, nine bone age methods were selected and applied retrospectively in pilot study (thirteen individuals), followed by evaluation of EOS images of 934 4-24-year-olds. Difficulty of assessment and time taken were recorded, and reliability calculated. RESULTS: Five methods proved promising after pilot study. Risser 'plus' could be applied with no difficulty in 89.5% of scans (836/934) followed by the Oxford hip method (78.6%, 734/934), cervical (79.0%, 738/934), calcaneus (70.8%, 669/934) and the knee (68.2%, 667/934). Calcaneus and cervical methods proved to be fastest at 17.7s (95% confidence interval, 16.0s to 19.38s & 26.5s (95% CI, 22.16s to 30.75s), respectively, with Oxford hip the slowest at 82.0 s (95% CI, 76.12 to 87.88s). Difficulties included: regions lying outside of the image-assessment was difficult or impossible in upper cervical vertebrae (46/934 images 4.9%) and calcaneus methods (144/934 images, 15.4%); position: lower step length was associated with difficult lateral knee assessment & head/hand position with cervical evaluation; and resolution: in the higher stages of the hip, calcaneal and knee methods. CONCLUSIONS: Hip, iliac crest and cervical regions can be assessed on the majority of EOS scans and may be useful for retrospective application. Calcaneus evaluation is a simple and rapidly applicable method that may be appropriate if consideration is given to include full imaging of the foot.

Maximal Axial Vertebral Rotation in Adolescent Idiopathic Scoliosis: Is the Apical Vertebra the Most Rotated?

STUDY DESIGN: Retrospective cross-sectional study. OBJECTIVES: It is generally believed that the apical vertebra has the largest axial rotation in adolescent idiopathic scoliosis. We investigated the relationship between apical axial vertebral rotation (apicalAVR) and maximal axial vertebral rotation (maxAVR) in both major and minor curves using biplanar stereo-imaging. METHODS: EOS 2D/3D biplanar radiograph images were collected from 332 patients with adolescent idiopathic scoliosis (Cobb angle range 10°-122°, mean age 14.7 years). Based on the X-ray images, with the help of 3D full spine reconstructions Cobb angle, curvature level, apicalAVR and maxAVR were determined. These parameters were also determined for minor curves in Lenke 2, 3, 4, 6 type patients. Maximal thoracic rotation and maximal thoracolumbar/lumbar rotation were calculated. Statistical analysis was performed with descriptive statistics, Shapiro-Wilk test, and Wilcoxon signed-rank test. RESULTS: The apical vertebrae were the most rotated vertebra in only 40.4% of the major curves, and 31.7% in minor curves. MaxAVR significantly exceeded apicalAVR values in the major curves (P < .001) as well as in minor curves (P < .001). The 2 parameters differed significantly in each severity group and Lenke type. CONCLUSIONS: The apical vertebrae were not the most rotated vertebra in more than half of cases investigated indicating that apicalAVR and maxAVR should be considered as 2 distinct parameters, of which maxAVR fully describes the axial dimension of scoliosis. Furthermore, the substitution of maxAVR for the apicalAVR should be especially avoided in double and triple curves, as the apical vertebra was even less commonly the most rotated in minor curves.

Three-dimensional efficacy of correction surgeries in adolescent idiopathic scoliosis / Gerinckorrekciós mutétek háromdimenziós hatékonysági vizsgálata serdülokori idiopathiás gerincferdülésben.

Összefoglaló. Bevezetés: Nincs egységesen elfogadott álláspont, hogy a serdülokori idiopathiás gerincferdülés sebészi korrekcióját melyik életkorban optimális elvégezni. Világszerte 11 éves kortól akár (kezeletlen esetben) 50-60 éves korig végeznek fúziós mutétet a betegségben, 63-83%-os átlagos koronális síkú korrekciós hatékonysággal. Célkituzés: Célul tuztük ki, hogy felmérjük a gerinckorrekciós mutétek hatékonyságát három dimenzióban, illetve a páciens életkorának függvényében. Módszerek: A vizsgálatba 23, serdülokori idiopathiás gerincferdüléssel diagnosztizált beteget (12 fo 17 évnél fiatalabb, 11 fo 17 évnél idosebb) vontunk be. Minden betegnél csavaros derotációt és spondylodesist végeztünk, és a beavatkozás elott és után EOS 2D/3D felvételeket, majd sterEOS 3D rekonstrukciókat készítettünk. A következo paramétereket számítottuk: Cobb-fok, háti kyphosis, ágyéki lordosis, apicalis csigolyarotáció, maximális csigolyarotáció. A különbözo életkorú csoportok közötti különbséget kétmintás t-próbával, illetve Wilcoxon-féle próbával vizsgáltuk. Eredmények: A gerinckorrekciós mutétek során a koronális síkú eltérést 78,2%-ban (átlagosan 55,1 Cobb-fokról 12,0 Cobb-fokra), az apicalis csigolyarotációt 56,7%-ban (átlagosan 21,0 fokról 9,1 fokra) tudtuk korrigálni. A 17 éves életkor után operált páciensek esetén átlagosan 79,2%-os Cobb-fok-csökkenést értünk el, míg a fiatalabb betegcsoportban 77,0%-ban korrigáltuk a koronális fogörbületet (p = 0,614). Az idosebb betegcsoportban szignifikánsan kevésbé sikerült az apicalis csigolyarotáció korrekciója (átlagosan 38,1%; 21,8 fokról 12,4 fokra), mint a fiatalabb pácienseknél (átlagosan 68,5%; 20,2 fokról 6,2 fokra; p = 0,016). Következtetés: Összességében a nemzetközi publikációknak megfelelo korrekciót értünk el. A koronális síkban közel azonos korrekciós hatékonyság figyelheto meg a különbözo életkorú betegcsoportok között, a csigolyarotáció azonban 17 éves életkor elott hatékonyabban korrigálható. Orv Hetil. 2021; 162(39): 1573-1578. INTRODUCTION: There is no clear recommendation for the optimal age to perform corrective surgery in adolescent idiopathic scoliosis. Fusion surgery is performed from the age of 11 to 50-60 years, with an average coronal plane correction efficiency of 63-83%. OBJECTIVE: We aimed to evaluate the effectiveness of correction surgeries in three dimensions in adolescent idiopathic scoliosis. In addition, our objective was to examine the influence of the patient's age on the correction. METHODS: The study included 23 patients with adolescent idiopathic scoliosis (12 patients younger than 17 years, 11 patients older than 17 years). All patients underwent screw-derotation and spondylodesis and underwent EOS 2D/3D imaging before and after the operation, followed by sterEOS 3D reconstructions. The following parameters were calculated: Cobb degree, thoracic kyphosis, lumbar lordosis, apical vertebral rotation, maximal vertebral rotation. Differences between different age groups were examined by paired-sample t-test and Wilcoxon rank sum test. RESULTS: The mean efficiency of correction surgeries was 78.2% in the coronal plane (from an average of 55.1 Cobb degrees to 12.0 Cobb degrees) and 56.7% in the axial plane (from an average of 21.0 degrees to 9.1 degrees). We achieved an average 79.2% reduction of Cobb angle in patients operated after the age of 17 years, which was 77.0% in the younger group (p = 0.614). Apical vertebral rotation correction was significantly less successful in the elderly group (mean 38.1%; from 21.8 degrees to 12.4 degrees) than in patients operated before the age of 17 years (mean 68.5%; from 20.2 degrees to 6.2 degrees; p = 0.016). CONCLUSION: We achieved scoliosis correction in line with the international publications. Nearly the same correction efficiency was observed between different age groups of patients in the coronal plane. However, vertebral rotation can be derotated more effectively before the age of 17 years. Orv Hetil. 2021; 162(39): 1573-1578.

Effectivity of near-peer teaching in training of basic surgical skills - a randomized controlled trial.

BACKGROUND: Near-peer teaching (NPT) is a special way of teaching where the tutor is one or more academic years ahead of the person being tutored. The literature agrees on the benefits of the method, but there are only a few publications examining its effectiveness using objective methods. The aim of our study was to examine the effectiveness of NPT in the training of basic surgical skills. METHODS: We included 60 volunteer students who participated in a 20 × 45 min long surgical skills course. Based on the results of a pre-course test, we randomly divided the students into six equal groups. All groups completed the same curriculum, with three groups being assisted by a NPT tutor. After the course, they completed the same test as at the beginning. The exams were recorded on anonymized videos and were blindly evaluated. The students' satisfaction was monitored using a self-administered online anonymous questionnaire. Statistical analysis was performed using the Mann-Whitney and Wilcoxon tests. RESULTS: Overall, student performance improved with completion of the course (from 119.86 to 153.55 points, p <  0.01). In groups where a NPT tutor assisted, students achieved a significantly better score (37.20 vs. 30.18 points improvement, p = 0.036). The difference was prominent in surgical knotting tasks (14.73 vs. 9.30 points improvement, p <  0.01). In cases of suturing (15.90 vs. 15.46 points) and laparoscopy (7.00 vs. 4.98 points), the presence of the NPT tutor did not significantly affect development. Based on student feedback, although students positively assessed the presence of NPT, it did not significantly improve students' overall satisfaction since it was already 4,82 on a scale of 5 in the control group. CONCLUSIONS: Overall, involving a NPT tutor had a positive impact on student development. An outstanding difference was observed in connection with knotting techniques.

[Bone age - alternatives for skeletal maturity assessment for the EOS scanner]. / Csontkor ­ a csontrendszeri érettség mérésének lehetosége EOS készülékkel.

INTRODUCTION: Hand and wrist bone age assessment methods cannot be performed when using the recommended patient position within the EOS scanner. AIM: We aimed to assess alternative methods for use with the EOS. METHOD: After investigating 9 alternatives, five methods were selected - cervical vertebra (Hassel-Farman), iliac crest (Risser 'plus'), hip (Oxford), knee (O'Connor), calcaneus (Nicholson) - and applied to EOS scans of 114, 2-21-year-old normal individuals. Intraclass correlation coefficient tests for reliability and Spearman correlation with calendar age were assessed. RESULTS: Intra- and interobserver reliabilities were all excellent, except with the knee method (0.865 - 'good'). Calcaneal and cervical methods were the fastest to apply (mean 17.5 s, 33.4 s per evaluation), however, calcanei were unassessable in 14% of scans (versus 1% of cervical). All methods correlated significantly with calendar age (r>0.829, p<0.05). Difficulties were principally absent (12%) or obscured (23%) landmarks. CONCLUSION: Bone age assessment is possible with all 5 methods, however, the Hassel-Farman method proved to be easily useable, fast and reliable. Orv Hetil. 2019; 160(16): 619-628.

Sagittal plane assessment of spino-pelvic complex in a Central European population with adolescent idiopathic scoliosis: a case control study.

BACKGROUND: Scoliosis is a complex three-dimensional deformity. While the frontal profile is well understood, increasing attention has turned to balance in the sagittal plane. The present study evaluated changes in sagittal spino-pelvic parameters in a large Hungarian population with adolescent idiopathic scoliosis. METHODS: EOS 2D/3D images of 458 scoliotic and 69 control cases were analyzed. After performing 3D reconstructions, the sagittal parameters were assessed as a whole and by curve type using independent sample t test and linear regression analysis. RESULTS: Patients with scoliosis had significantly decreased thoracic kyphosis (p < 0.001) with values T1-T12, 34.1 ± 17.1o vs. 43.4 ± 12.7o in control; T4-T12, 27.1 ± 18.8o vs. 37.7 ± 15.1o in control; and T5-T12, 24.9 ± 15.8o vs. 32.9 ± 15.0o in control. Changes in thoracic kyphosis correlated with magnitude of the Cobb angle (p < 0.001). No significant change was found in lumbar lordosis and the pelvic parameters. After substratification according to the Lenke classification and individually evaluating subgroups, results were similar with a significant decrease in only the thoracic kyphosis. A strong correlation was seen between sacral slope, pelvic incidence, and lumbar lordosis, and between pelvic version and thoracic kyphosis in control and scoliotic groups, whereas pelvic incidence was also seen to be correlated with thoracic kyphosis in scoliosis patients. CONCLUSION: Adolescent idiopathic scoliosis patients showed a significant decrease in thoracic kyphosis, and the magnitude of the decrease was directly related to the Cobb angle. Changes in pelvic incidence were minimal but were also significantly correlated with thoracic changes. Changes were similar though not identical to those seen in other Caucasian studies and differed from those in other ethnicities. Scoliotic curves and their effect on pelvic balance must still be regarded as individual to each patient, necessitating individual assessment, although changes perhaps can be predicted by patient ethnicity.

The effect of coronal decompensation on the biomechanical parameters in lower limbs in adolescent idiopathic scoliosis.

STUDY HYPOTHESIS: We hypothesized that altered coronal balance in adolescent scoliosis leads to asymmetric stress on the lower limbs, with subsequent effects on bone maturation and later morphology. We aimed to assess the correlation between the biomechanical parameters of the lower limbs and coronal balance in idiopathic scoliosis. MATERIALS AND METHODS: In this study, EOS images of 280 patients and 56 controls were randomly selected from our clinics' database. The average age of AIS patients was 14.5years and average Cobb angle 33.48°. Three D reconstructions of the pelvis and lower limbs were performed and coronal balance assessed. Reliability of measurements was ensured by intra- and inter-observer agreement. During statistical analysis the Kolmogorov-Smirnov test, t-test and linear regression analysis were performed. A p value <0.05 was considered significant. RESULTS: Of the 15 examined lower limb parameters, a significant difference between sides was found in those with AIS for femur length, total length, collodiaphyseal angle, angle between the femoral mechanical and anatomical axis and tibial torsion. In addition, the tibial length and the mechanical tibiofemoral angle were significantly higher than those of the controls. The coronal balance was found to be the strongest predictive factor showing a significant correlation with all of the previous parameters, except tibial torsion. With patients grouped based on coronal balance (compensated, right and left decompensated) the paired t-test also supported these findings. CONCLUSION: The biomechanical parameters of the lower limbs are affected in cases of scoliosis with an altered coronal balance. It was thought that a shift in balance in the coronal plane accounted for the small but significant changes seen in our study, with the lower limb on the side of decompensation becoming shorter in comparison to its' counterpart, with a lower collodiaphyseal angle and increased varus at the knee joint. LEVEL OF EVIDENCE: III, case-control study.

Determination and correlation of lower limb anatomical parameters and bone age during skeletal growth (based on 1005 cases).

The aim of this study was to evaluate bone age and its correlation with the lower limbs' developing skeletal anatomy during growth. 1005 children and young adults were evaluated for bone age and 14 different parameters measured on lower-limb reconstructions from radiological examinations carried out with an EOS 2D/3D system in the course of routine orthopedic indicated diagnostic practice. Cervical vertebral morphology evaluation for bone age using the Hassel-Farman method, which describes six stages of maturity, was selected. Intra- and inter-observer reliability tests for this method, and for the EOS 3D reconstructions were performed. Statistical analysis were performed using Spearman correlation, multiple linear regression, and t-test. The intra- and inter-observer reliability of the Hassel-Farman method and the EOS 3D lower-limb reconstruction were found to be excellent. Interestingly one bone age stage could include individuals across a 12.1 year range, and conversely individuals of the same calendar age could be of one of 3.2 different bone age stages. In the prepubertal age groups all six bone stages could be observed. Bone age revealed a stronger relationship, lower standard deviations with groups and proved to be a better discriminating variable than the calendar age by collodiaphyseal angle, femoral, and tibial torsion, femorotibial rotation, and mechanical tibiofemoral angle. Bone age is an indicator of skeletal maturity and may more accurately describe the growth of some lower limb parameters. As a result we suggest the consideration of bone age when evaluating lower-limb biomechanic-anatomical parameters. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1431-1441, 2017.

Three dimensional radiological imaging of normal lower-limb alignment in children.

PURPOSE: Our study aimed at evaluating age- and gender-specific references describing lower-limb alignment in a large population of children using an accurate and reliable method (EOS 2D/3D). METHODS: From our database, we selected 523 EOS records suitable for 3D modelling representing age groups between two and 16 years in which no relevant deviation influencing lower-limb biomechanics could be observed (the majority of the examined population had mild scoliosis). We performed reconstruction of both lower limbs, thus obtaining the value of the mechanical tibiofemoral angle (mTFA) and the femoral mechanical axis-femoral shaft angle (FM-FS) and calculated the anatomical tibiofemoral angle (aTFA) from previous parameters. Statistical analysis was carried out using the Kolmogorov-Smirnov test, Spearman correlation, regression analysis and Welch test. RESULTS: The aTFA reaches its maximum by the age of three years: 13.07° in boys and 10.73° in girls; it then varies ∼4.44° in both genders. By the age of three years, the mTFA reaches 8.04° in boys and 4.85° in girls; it starts to decrease to -1.47° in boys and 0.13° in girls. By the age of three years, FM-FS increases to 5.02° in boys, then fluctuates at ∼4.08°, while in girls, it increases to 5.87°, then fluctuates at ∼4.24°. CONCLUSIONS: The pattern found in this study confirms the results of previous publications investigating Caucasian populations; however, absolute values differ significantly in several cases.

Three-dimensional quantitative analysis of the proximal femur and the pelvis in children and adolescents using an upright biplanar slot-scanning X-ray system.

BACKGROUND: The anatomy and biomechanics of the pelvis and lower limbs play a key role in the development of orthopaedic disorders. OBJECTIVE: This study aimed to establish normal reference standards for the measurement of gender-specific pelvic and femoral parameters in children and adolescents with the EOS 2-D/3-D system. MATERIALS AND METHODS: EOS 2-D images of 508 individuals (ages 4-16 years) were obtained as part of routine diagnostics. Patients with lower limb abnormalities were excluded. Pelvic and femoral surface 3-D models were generated and clinical parameters calculated by sterEOS 3-D reconstruction software. Data were evaluated using Spearman correlation, paired-samples and independent-samples t-test and linear regression analysis. RESULTS: Changes in anatomical parameters were found to correlate with age and gender in 1) femoral mechanical axis length: 27.3-43.7 cm (males), 25.5-41.2 cm (females), 2) femoral head diameter: 29.4-46.1 mm (males), 27.7-41.3 mm (females), 3) femoral offset: 26.8-42.4 mm (males), 25.5-37.9 mm (females) and 4) femoral neck length: 35.1-52.9 mm (males), 32.8-48.1 mm (females). There was no gender-specific correlation for the neck shaft angle with values from 130.4° to 129.3°, for femoral torsion (22.5°-19.4°), for sacral slope (39.0°-44.4°) and for lateral pelvic tilt (5.1 mm-6.2 mm). Sagittal pelvic tilt exhibited no significant correlation with age showing average values of 6.5°. CONCLUSIONS: The EOS 2-D/3-D system proved to be a valuable method in the evaluation of female and male developmental changes in pelvic and lower limb anatomical parameters, in normal individuals younger than 16 years of age.

[Evaluation of the usefulness of the EOS 2D/3D system for the measurement of lower limbs anatomical and biomechanical parameters in children]. / Az EOS 2D/3D System alkalmazhatóságának vizsgálata a szabad alsó végtag anatómiai és biomechanikai paramétereinek mérésére gyermekkorban.

INTRODUCTION: Lower limbs anatomical and biomechanical parameters are essential in several paediatric orthopaedic disease, which makes their exact measurement necessary. AIM: The aim of the author was to evaluate the reliability of the EOS 2D/3D System, a 3D reconstruction capable imaging device in children. METHOD: 3D reconstructions were performed in 523 cases aged between 2 and 16 years in whom no abnormality influencing lower limbs biomechanics was observed. For statistical analysis intraclass correlation, paired-samples t-test, Spearman-correlation and Welch-test were used. RESULTS: Excellent results were found for all parameters in reliability test used by the operator. The step-forward position used during the examination influenced the sagittal tibiofemoral angle only. All examined parameters showed significant correlation with age and gender. Height correlated with neck-shaft angle, hip-knee shift, femoral and tibial torsion only. CONCLUSIONS: The EOS technology proved to be an appropriate method to measure lower limbs anatomical parameters in children. Changes in these parameters during development correlated with age and gender.