EOS analysis of lower extremity segmental torsion in children and young adults

Introduction Lower limb torsion varies substantially among healthy children during growth. Values reported in the literature to date have been obtained using semi-quantitative clinical or 2D measurement methods. Quantitative 3D measurement would help determine the physiological range of lower limb torsion. Low-dose stereoradiography with 3D reconstruction provides a good alternative. Its use increases in pediatrics because of radiation minimization. Previous studies have shown accurate and reproducible results of lower limbs reconstruction in adults and children but the torsional parameters haven’t been measured yet. The present study reports the values of lower limb segmental torsion and its course during growth in a cohort of healthy children and young adults using the EOS low-dose biplanar X-ray. Hypothesis EOS 3D reconstruction is an accurate and reproducible method to measure the torsional parameters in children. Materials and methods Femoral torsion (FT) and tibial torsion (TT) were studied on 114 volunteers (228 lower limbs) from 6 to 30 years of age divided by age into 5 groups. The EOS™ acquisitions were obtained in subjects standing with their feet offset. Results Mean FT decreased during growth, passing from 21.6° to 18°, whereas mean TT increased from 26.8° to 34.7°. There was a statistically significant difference between the 2 extreme age groups, but no difference was found between any other age groups. The ICC for intra-observer reproducibility was 0.96 and 0.95 for FT and TT for the first operator, and 0.79 and 0.83 for the second operator respectively. The ICC for inter-observer reproducibility was 0.84 and 0.82 respectively. Discussion The course of lower limb segmental torsion observed was consistent with literature reports based upon clinical and 2D measurements. 3D reconstruction of EOS low-dose biplanar imaging appears to be a safe and reliable tool for lower limbs measurements, especially for investigating lower limb segmental torsion in children and adults

Titanium vs cobalt chromium: what is the best rod material to enhance adolescent idiopathic scoliosis correction with sublaminar bands?

PURPOSE: Cobalt chromium (CoCr) rods have recently gained popularity in adolescent idiopathic scoliosis (AIS) surgical treatment, replacing titanium (Ti) rods, with promising frontal correction rates in all-screw constructs. Posteromedial translation has been shown to emphasize thoracic sagittal correction, but the influence of rod material in this correction technique has never been investigated. The aim of this study was to compare the postoperative correction between Ti and CoCr rods for the treatment of thoracic AIS using posteromedial translation technique. METHODS: 70 patients operated for thoracic (Lenke 1 or 2) AIS, in 2 institutions, between 2010 and 2013, were included. All patients underwent posterior fusion with hybrid constructs using posteromedial translation technique. The only difference between groups in the surgical procedure was the rod material (Ti or CoCr rods). Radiological measurements were compared preoperatively, postoperatively and at last follow-up (minimum 2 years). RESULTS: Preoperatively, groups were similar in terms of coronal and sagittal parameters. Postoperatively, no significant difference was observed between Ti and CoCr regarding frontal corrections, even when the preoperative flexibility of the curves was taken into account (p = 0.13). CoCr rods allowed greater restoration of T4T12 thoracic kyphosis, which remained stable over time (p = 0.01). Most common postoperative complication was proximal junctional kyphosis (n = 4). However, no significant difference was found between groups regarding postoperative complications rate. CONCLUSION: CoCr and Ti rods both provide significant and stable frontal correction in AIS treated with posteromedial translation technique using hybrid constructs. However, CoCr might be considered to emphasize sagittal correction in hypokyphotic patients

Correction of hypokyphosis in thoracic adolescent idiopathic scoliosis using sublaminar bands: a 3D multicenter study

INTRODUCTION: The comparison of implants and correction methods remain controversial in AIS. Excellent frontal and axial correction rates have been reported with all-screw constructs, but at the expense of sagittal alignment, which has a tendency to flatten postoperatively. Posteromedial translation using hybrid constructs seems to preserve and improve thoracic kyphosis (TK), but no series exist to date with a significant number of hypokyphotic patients. In addition, the measures of TK in 2D are often wrong in severe AIS due to axial rotation. The goals of this study were therefore to analyze the 3D radiological outcomes of a group of hypokyphotic AIS patients operated with sublaminar bands. METHODS: 35 consecutive AIS hypokyphotic patients (T4T12 <15°) operated in three centers were included, with a minimum 2-year follow-up. The surgical technique was similar in all centers, associating lumbar pedicle screws and thoracic sublaminar bands. Posteromedial translation was the main correction technique, and no patient underwent prior anterior release. 3D spinal reconstructions were performed preoperatively, postoperatively and at the latest follow-up by an independent observer using SterEOS (EOS imaging, Paris, France), and 2D and 3D measurements were compared. In addition, a new 3D parameter [sagittal shift of the apical vertebra (SSAV)], reflecting the translation of the apical vertebra of the main curve in the patient sagittal plane, was described and reported. RESULTS: The age of the cohort was 16 years and the number of sublaminar bands used for correction averaged 6 (±1.5). T1T12 and T4T12 sagittal Cobb angles appeared to be overestimated on 2D postoperatively (3°, p = 0.002 and 4°, p < 0.001, respectively). Hence, only 3D measurements were kept for the quantitative analysis of the postoperative correction. T4T12 TK significantly increased after surgery (average 8° ± 7°, p < 0.001), but 11 patients (31.4%) remained hypokyphotic. Seven out of the eight patients (87.5%) who presented a thoracic lordosis (i.e., T4T12 <0°) preoperatively were corrected after surgery (mean gain 16° ± 4°). A posterior shift (positive SSAV) of the apical vertebra was reported in 24 patients (68.6%). In this subgroup, the mean SSAV was +2 cm (±1). Good correlation was found between the SSAV and the postoperative change in 3D T4T12 kyphosis (r = 0.62). CONCLUSION: Measures in 2D tend to overestimate sagittal alignment and are not sufficient to evaluate postoperative correction. SSAV is a new 3D parameter reflecting the TK change that needs to be further investigated and used in the future. This series confirms that sublaminar bands should be considered in hypokyphotic patients, since thoracic sagittal alignment was restored in 68.6% of the cases

Clinical and stereoradiographic analysis of adult spinal deformity with and without rotatory subluxation

Introduction: In degenerative adult spinal deformity (ASD), sagittal malalignment and rotatory sublux-ation (RS) correlate with clinical symptomatology. RS is defined as axial rotation with lateral listhesis.Stereoradiography, recently developed for medical applications, provides full-body standing radiographsand 3D reconstruction of the spine, with low radiation dose.Hypothesis: 3D stereoradiography improves analysis of RS and of its relations with transverse plane andspinopelvic parameters and clinical impact.Material and methods: One hundred and thirty adults with lumbar ASD and full-spine EOS®radiographs(EOS Imaging, Paris, France) were included. Spinopelvic sagittal parameters and lateral listhesis in thecoronal plane were measured. The transverse plane study parameters were: apical axial vertebral rotation(apex AVR), axial intervertebral rotation (AIR) and torsion index (TI). Two groups were compared: with RS(lateral listhesis > 5 mm) and without RS (without lateral listhesis exceeding 5 mm: non-RS). Correlationsbetween radiologic and clinical data were assessed.Results: RS patients were significantly older, with larger Cobb angle (37.4◦vs. 26.6◦, P = 0.0001), moresevere sagittal deformity, and greater apex AVR and TI (respectively: 22.9◦vs. 11.3◦, P 10◦without visible RS on 2D radiographs. RS patientsreported significantly more frequent low back pain and radiculalgia.Discussion: In this EOS®study, ASD patients with RS had greater coronal curvature and sagittal and trans-verse deformity, as well as greater pain. Further transverse plane analysis could allow earlier diagnosisand prognosis to guide management.Level of evidence: 4, retrospective study.Master’s grant from the French Orthopedic and Traumatologic Surgery Society (SOFCOT), without which this research would not have been possible

Selective versus hyperselective posterior fusions in Lenke 5 adolescent idiopathic scoliosis: comparison of radiological and clinical outcomes

PURPOSE: Recent literature has reported that the ]progression risk of Lenke 5 adolescent idiopathic scoliosis (AIS) during adulthood had been underestimated. Surgery is, therefore, proposed more to young patients with progressive curves. However, choice of the approach and fusion levels remains controversial. The aim of this study was to analyze the influence of the length of posterior fusion on clinical and radiological outcomes in Lenke 5 AIS. METHODS: All Lenke 5 AIS operated between 2008 and 2012 were included with a minimum 2-year follow-up. Patients were divided into two groups according to the length of fusion. In the first group (selective), the upper instrumented level (UIV) was the upper end vertebra of the main structural curve and distally the fusion was extended to the stable and neutral vertebra, according to Lenke's classification. In the second group (hyperselective), shorter fusions were performed and the number of levels fused depended on the location of the apex of the curve (at maximum, 2 levels above and below, according to Hall's criteria). Apart from the fusion level selection, the surgical procedure was similar in both groups. Radiological outcomes and SRS-22 scores were reported. RESULTS: 78 patients were included (35 selective and 43 hyperselective). The number of levels fused was significantly higher in the first group (7.8 ± 3 vs 4.3 ± 0.6). None of the patients was fused to L4 in selective group. No correlation was found between length of fusion and complication rate. Eight patients had adding-on phenomenon among which 6 (75%) had initially undergone hyperselective fusions and had significantly higher postoperative lower instrumented vertebra (LIV) tilt. In the adding-on group, LIV was located above the last touching vertebra (LTV) in 62.5% of the cases and above the stable vertebra (SV) in 87.5%. Patients in the selective group reported a significantly lower score in the SRS function domain. CONCLUSION: Coronal alignment was restored in both groups. Hyperselective posterior fusions can be considered in Lenke 5 AIS, preserving one or two mobile segments, with similar clinical and radiological outcomes. However, selection of the LIV according to SV and LTV need to be accurately analyzed in order to avoid adding-on during follow-up

Efficacité du corset de dérotation nocturne dans la scoliose idiopathique de l'adolescent (résultats préliminaires d'une série de 67 patients avec un recul minimum de 2 ans)

La scoliose idiopathique est une déformation tridimensionnelle du rachis dont l étiologie est indéterminée. Son traitement s impose en période de croissance lorsqu on a fait la preuve de son évolutivité. Depuis plus d un demi-siècle, diverses orthèses ont été développées et ont montré une certaine efficacité à contrôler la déformation dans le plan frontal. Aucune n est apte à prévenir l aggravation du profil, la plupart favorisant même l apparition d une lordose thoracique. Cette thèse présente une nouvelle orthèse dans le traitement conservateur de la scoliose idiopathique. Le Corset de Dérotation Nocturne (CDN), mis au point par le Pr K.Mazda (Hôpital Robert Debré, Paris) est une orthèse innovante qui se donne un double objectif: contrôler durablement l évolution de la courbure scoliotique et prévenir les perturbations du plan sagittal. L objectif de notre travail était d évaluer son efficacité sur une série prospective de 67 patients suivis au moins 2 ans après l arrêt du traitement, répondant à des critères d inclusion précis : scoliose idiopathique de l adolescent (âge au diagnostic?: 10 ans), courbure évolutive de 200 à 450, Risser <2, patiente préménarche ou traitée moins de 6 mois après les premières règles, pas d autre traitement préalable. L efficacité du corset a été jugée sur la progression angulaire de la courbure, une progression de plus de 50 en fin de traitement étant considérée comme un échec, ainsi que sur l évolution du profil rachidien. Soixante sept patients (61 filles, 6 garçons), âgés de 12,8 ans (10,5 à 16 ans), ont été suivis et traités entre 1997 et 2005 à l Hôpital Robert Debré par le promoteur du corset. Les patients étaient majoritairement à Risser O ou 1 (85%). L angle de Cobb initial était de 25,7 (20 à 44). La durée moyenne du port du corset était de 32 mois. Près de 75% des patients étaient jugés compliants. L angle de Cobb final était de 23,7. Le taux d échec était de 25% (13 patients ont progressé et 4 ont été perdus de vue au cours de l étude). Une indication opératoire a été portée dans 6 cas (8,9%). Six patientes ont développé une courbure thoracique supérieure au cours du traitement. Les facteurs pronostiques étaient l amplitude initiale de la courbure, le siège de la courbure, sa réductibilité initiale, le potentiel de croissance restant au début du traitement et la compliance. L amplitude finale des patients compliants était de 2 1,9. Le profil était significativement amélioré, y compris pour les scolioses thoraciques. La cyphose thoracique finale était de 30. Les paramètres pelviens n ont pas été modifiés. Le CDN est donc une orthèse efficace dans le traitement de la scoliose idiopathique de l adolescent. Il agit sur toutes les composantes spatiales de la déformation rachidienne, en particulier, il n aggrave pas les courbures sagittales. Le port nocturne est bien toléré et semble améliorer l observance du protocole thérapeutique. Une évaluation objective de la compliance, corrélée à une évaluation de la qualité de vie de ces patients serait nécessaire pour confirmer l innocuité et la bonne tolérance du CDNPARIS13-BU Serge Lebovici (930082101) / SudocSudocFranceF

Planification des niveaux de fusion dans les arthrodèses pour scoliose idiopathique de l'adolescent

PARIS7-Xavier Bichat (751182101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Analyse tridimensionnelle de la correction des scolioses idiopathiques de l'adolescent par translation postéromédiale

La scoliose idiopathique est une déformation tridimensionnelle du tronc, affectant le rachis et la cage thoracique. La stéréoradiographie basse dose EOS permet une analyse personnalisée en 3D de la géométrie du squelette en position debout. L'objectif de cette thèse est d'améliorer l'évaluation quantitative en routine clinique des résultats chirurgicaux, et d'y intégrer l'étude de la morphologie de la cage thoracique. Dans un premier temps, les outils, méthodes et protocoles nécessaires à une telle évaluation ont été mis en place et validés. En particulier, l'incertitude des reconstructions des déformations sévères et des rachis instrumentés a été quantifiée pour la première fois. La méthode a ensuite été appliquée à une série d'adolescents opérés de scoliose thoracique idiopathique par translation postéromédiale. La première partie de l'analyse quantitative a porté sur le rachis instrumenté, en incluant un nouvel axe de référence pour apprécier l'équilibre. Les résultats ont permis d'évaluer la correction obtenue dans le plan axial par cette méthode. La seconde partie de l'étude a porté sur les modifications postopératoires observées au niveau du rachis cervical. Une amélioration de l'alignement sagittal de ce segment non instrumenté, corrélée à la restauration de la cyphose thoracique, a été mise en évidence. La stéréoradiographie a enfin permis de faire une analyse descriptive de la morphologie endo et exothoracique d'un groupe de 80 adolescents suivis pour scoliose thoracique idiopathique, et d'étudier les corrélations entre paramètres quantitatifs thoraciques et rachidiens et épreuves fonctionnelles respiratoires. La méthode de modélisation du thorax a finalement été appliquée pour caractériser les modifications postopératoires. Ces travaux ont ainsi confirmé l'intérêt de l'analyse 3D du rachis et du thorax dans l'évaluation en routine clinique des résultats chirurgicaux de scolioses idiopathiques.Idiopathic scoliosis is a tridimensional trunk deformity, affecting both the spine and the rib cage. Low dose EOS stereoradiography is designed to assess the patient specific 3D geometry of the skeleton in standing position. The goal of this work is to improve the quantitative analysis of postoperative results in a routine clinical use, and to integrate the rib cage morphological analysis. Tools, methods and necessary proocols were first developed and validated to allow such an evaluation. In particular, the reliability of 3D measurements in severe scoliosis and instrumented spine were assessed. The modelization method was then applied to a series of adolescents operated for thoracic idiopathic scoliosis using posteromedial translation. The first part of the analysis focused on the instrumented spine, and included a new reference axis to estimate patients' global balance. The second part of the work aimed to describe the postoperative change of the sagittal cervical alignement. Significant improvement was found, correlated with thoracic kyphosis restoration. Finally, biplanar stereoradiography allowed a descriptive analysis of the endo and exothoracic morphology in a cohort of 80 adolescents with idiopathic scoliosis. Correlations between quantitative spinal and thoracic parameters and pulmonary function tests were investigated. The method was used in order to characterize the postoperative thoracic changes. This study confirms the interest of having in routine clinical use a 3D evaluation of the spine and the rib cage in the quantitative analysis of idiopathic scoliosis postoperative results.PARIS-Arts et Métiers (751132303) / SudocSudocFranceF

Junctional kyphosis after the treatment of adolescent idiopathic scoliosis

Introduction: In this retrospective study radiographic review was undertaken in patients treated for AIS (Adolescent Idiopathic Scoliosis), in order to determine the most important preoperative factors that are seen with postoperative junctional kyphosis.Material &amp;Methods: Sagittal spine profiles were measured on the standing radiographs before surgery, after surgery and in the last follow-up postoperative visit of the patients with AIS. The following parameters were measured on lateral views: lumbar lordosis, thoracic kyphosis, the sagittal offset distance of C7 to a vertical line from postero-superior edge of S1 (Sagittal Vertical Axis-SVA) and T9 sagittal offset angle. Results: One hundred and twenty patients with a mean 42 months of follow-up (24-112 months) were included in the study. Mean values of the parameters before corrective surgery were: lumbar lordosis 45° ± 13.6°, thoracic kyphosis 28°±18.4°, SVA 35 ± 27.2 mm and T9 offset angle, 7.8°± 5.1°. Mean values at last follow-up were: lumbar lordosis 49± 9.8°, thoracic kyphosis 35 ± 16.4°, SVA 39 ± 24 mm and T9 offset angle, 8.6°±5.8°. There were 10 upper junctional kyphosis (8.4%). T test statistics revealed significant correction of lumbar lordosis and thoracic kyphosis after fusion in all patients (P&lt;0.001, P=0.006 respectively). Preoperative mean of T9 sagittal offset angle was higher in the patients with proximal junctional kyphosis (P=0.006).Conclusion: Normal sagittal balance of spine is essential for the optimum function of the intervertebral disks and preventing sagittal postoperative complication like proximal junctional kyphosis. More attention to preoperative sagittal parameters of the spine like T9 offset may be important to prevent such complications