Assessment of malalignment at early stage in adolescent idiopathic scoliosis: a longitudinal cohort study.

INTRODUCTION: Our objective was to assess abnormalities of the odontoid-hip axis (OD-HA) angle in a mild scoliotic population to determine whether screening for malalignment would help predict the distinction between progressive and stable adolescent idiopathic scoliosis (AIS) at early stage. MATERIALS AND METHODS: All patients (non-scoliotic and AIS) underwent a biplanar X-ray between 2013 and 2020. In AIS, inclusion criteria were Cobb angle between 10° and 25°; Risser sign lower than 3; age higher than 10 years; and no previous treatment. A 3D spine reconstruction was performed, and the OD-HA was computed automatically. A reference corridor for OD-HA values in non-scoliotic subjects was calculated as the range [5th-95th percentiles]. A severity index, helping to distinguish stable and progressive AIS, was calculated and weighted according to the OD-HA value. RESULTS: Eighty-three non-scoliotic and 205 AIS were included. The mean coronal and sagittal OD-HA angles in the non-scoliotic group were 0.2° and -2.5°, whereas in AIS values were 0.3° and -0.8°, respectively. For coronal and sagittal OD-HA, 27.5% and 26.8% of AIS were outside the reference corridor compared with 10.8% in non-scoliotic (OR = 3.1 and 3). Adding to the severity index a weighting factor based on coronal OD-HA, for thoracic scoliosis, improved the positive predictive value by 9% and the specificity by 13%. CONCLUSION: Analysis of OD-HA suggests that AIS patients are almost three times more likely to have malalignment compared with a non-scoliotic population. Furthermore, analysis of coronal OD-HA is promising to help the clinician distinguish between stable and progressive thoracic scoliosis.

Kyphectomy in myelomeningocele revisited: risk factors for failure.

PURPOSE: Lumbar kyphosis occurs in approximately 8-20% of patients with myelomeningocele (MMC). The purpose of this article is to analyze the risks and benefits of vertebrectomy and spinal stabilization in MMC children with severe lumbar kyphosis and to establish treatment guidelines. METHODS: This is an IRB-approved retrospective analysis of 59 patients with MMC who underwent kyphectomy and posterior instrumentation in three centers. Average age at surgery was 7.9 years (2 weeks-17 years). Sitting trunk position, skin status, kyphosis angle, and thoracic lordosis were analyzed preoperatively, postoperatively, and at an average follow-up of 8.2 years (range 2.5-16). The correction was maintained by applying a short posterior instrumentation in 6 patients, and extending to the pelvis in 53 cases. Pelvic fixation was achieved using the Warner and Fackler technique in 24 patients, the Dunn-McCarthy in 8, Luque-Galveston in 8, sacral screws in 2, and ilio-sacral screws in 11. RESULTS: Sitting position improved postoperatively in 47 of the 53 patients who underwent pelvic fixation and only in one patient with short instrumentation. All 6 patients with long instrumentation and poor postoperative sitting balance were in the Dunn-McCarthy fixation group. Skin sores at the apex of the deformity disappeared postoperatively in all patients but recurred in two patients with short instrumentations. Kyphosis angle improved from 109° (45°-170°) preoperatively to 10° (0°-45°) postoperatively and 21° (0°-55°) at last follow-up. The best results were seen in cases where a cross-k-wire fixation of the kyphectomy site was used, augmented with a long thoraco-pelvic instrumentation consisting of Luque sublaminar wires in the thoracic region and a Warner-Fackler type of pelvic fixation. Good results were also found with the bipolar technique and ilio-sacral screw fixation. Six over 24 patients with the Warner and Fackler technique showed gradual dislodgment or hardware failure, with subsequent nonunion of the kyphectomy site in four. Infection, with or without wound dehiscence and/or hardware exposure, occurred in 17 cases, necessitating hardware removal in 9 patients. CONCLUSION: Lumbar kyphosis in MMC children is best managed by resection of enough vertebrae from the apex to produce a flat lumbar spine, with perfect bone-to-bone contact and long thoraco-pelvic instrumentation using the Warner and Fackler technique through the S1 foramina or the bipolar technique with ilio-sacral screw fixation. Additional local fixation of the osteotomy site using cross-wires with or without cerclage increases the stability of the construct. The majority of complications occurred in patients with short instrumentations or where residual kyphosis persisted postoperatively regardless of the type of pelvic fixation or hardware density. The Dunn-McCarthy technique for pelvic fixation following kyphectomy in MMC was less successful in producing stable pelvic fixation and should not be considered in this patient category.

Long-term outcomes of ilio-sacral screws in minimally invasive bipolar fusionless technique for neuromuscular scoliosis: a retrospective study in 167 patients.

INTRODUCTION: Pelvic fixation in patients with neuromuscular scoliosis is difficult, due to their fragile general condition and poor bone quality. Many techniques have been described, associated with high rates of mechanical complications. The objective of this work was to evaluate the mechanical complications and long-term radiological results of ilio-sacral screw pelvic fixation. MATERIALS AND METHODS: 167 consecutive patients with neuromuscular scoliosis who underwent minimally invasive bipolar fixation with ilio-sacral screw pelvic fixation were retrospectively reviewed. The instrumentation consisted in a bilateral sliding rods construct extended from T1 to the sacrum, anchored proximally by double-hook claws and distally by ilio-sacral screws through a minimally invasive approach. Mechanical complications and radiographic measurements (angle of the major coronal curve, pelvic obliquity, lumbar lordosis) were evaluated preoperatively, postoperatively, and at the last follow-up. RESULTS: Mean operative age was 12 ± 3 years, and follow-up 6.4 years (3.0-10.4 years). Pelvic obliquity decreased from 20° preoperatively to 5° (77% correction) at last follow-up, Angle of the major coronal curve from 75° to 36° (52% correction), and lumbar lordosis from 28° to 38°. 16 mechanical complications in nine patients occurred: screw prominence (n = 1), connector failure (n = 4), screw malposition (n = 11). Unplanned surgery was required in seven cases, two were managed during rod lengthening, seven did not require treatment. CONCLUSION: In this series of neuromuscular patients operated by ilio-sacral screws as pelvic fixation, the results were stable with a mean follow-up of more than 6 years and the complication rate was reduced comparatively to the literature.

Scoliosis Research Society-22r score is affected by standing whole body sagittal alignment, age, and sex, but not by standing balance or skeletal muscle mass in healthy volunteers.

PURPOSE: Aging and spinal disease impair standing whole body sagittal alignment (WBS alignment), which leads to stooping. When WBS alignment deteriorates, compensatory mechanisms are activated to maintain standing posture. Increase of the compensation impairs health-related quality of life (HRQOL). The purpose of this research was to determine whether postural factors, age, and sex affect HRQOL. METHODS: This cross-sectional study evaluated the influence of WBS alignment, standing body sway (balance), skeletal muscle mass (SMM), aging, and sex on HRQOL in healthy volunteers (n = 150; mean age 40.9 years [20-76], 96 women). Age, sex, weight, height, and body mass index (BMI) were obtained. HRQOL was assessed with Scoliosis Research Society-22 (SRS-22r). WBS alignment and balance were measured by EOS imaging with simultaneous force plate measurement. SMM was measured using a medical body composition analyzer. Based on the bivariate analysis between the SRS-22r subtotal and all parameters, selected ten parameters were used for multivariate logistic regression analysis to identify affecting factors to SRS-22r. RESULTS: Men had significantly higher weight, height, BMI, and SRS-22r score in all domains. The L4-S1 lumbar lordosis angle was greater in men, and pelvic tilt and knee hyperextension were greater in women. Women had a more stable standing posture, whereas men had significantly higher SMM values. Multivariate logistic regression analysis revealed that age, sex, and TPA were identified as significant factors affecting SRS-22r. CONCLUSIONS: In healthy volunteers, SRS-22r is affected by aging, sex (woman had a lower score), and sagittal malalignment. Neither Standing balance nor SMM, however, affect SRS-22r.4.

Gravity center estimation for evaluation of standing whole body compensation using virtual barycentremetry based on biplanar slot-scanning stereoradiography - validation by simultaneous force plate measurement.

BACKGROUND: Whole body standing alignment (WBSA) in terms of biomechanics can be evaluated accurately only by referring the gravity line (GL) which lies on the gravity center (GC). Here, we introduce a method for estimating GL and simultaneous WBSA measurement using the EOS® imaging system and report on the reproducibility and reliability of the method. METHODS: A 3-dimensional (3D) avatar to estimate GC was created following three steps: 3D reconstruction of the bone based on EOS images; deformation into a generic morphotype (MakeHuman statistical model) before density integration with 3D rasterization of the full body into 1-mm3 voxels (the content of each voxel is considered homogeneous); computation of the density of all the voxels provides the center of mass, which can be projected onto the floor as the GC of the full body, providing the GL in relation to the WBSA. The repeatability, reproducibility, and accuracy of the estimated GC and body weight of the avatar were compared with clinical estimation using a force plate in healthy volunteers and patients with degenerative and deformative diseases. RESULTS: Statistical analyses of the data revealed that the repeatability and reproducibility of the estimation was high with intra-rater and inter-rater intraclass correlation coefficient. ≥0.999. The coordinate values of the GC and body weight estimation did not differ significantly between the avatar and force plate measurements, demonstrating the high accuracy of the method. CONCLUSION: This new method of estimating GC and WBSA is reliable and accurate. Application of this method could allow clinicians to quickly and qualitatively evaluate WBSA with GL with various spinal malalignment pathologies.

Effect of curve location on the severity index for adolescent idiopathic scoliosis: a longitudinal cohort study.

OBJECTIVES: Adolescent idiopathic scoliosis (AIS) is the most common spinal disorder in children. A severity index was recently proposed to identify the stable from the progressive scoliosis at the first standardized biplanar radiographic exam. The aim of this work was to extend the validation of the severity index and to determine if curve location influences its predictive capabilities. METHODS: AIS patients with Cobb angle between 10° and 25°, Risser 0-2, and no previous treatment were included. They underwent standing biplanar radiography and 3D reconstruction of the spine and pelvis, which allowed to calculate their severity index. Patients were grouped by curve location (thoracic, thoracolumbar, lumbar). Patients were followed up until skeletal maturity (Risser ≥ 3) or brace prescription. Their outcome was compared to the prediction made by the severity index. RESULTS: In total, 205 AIS patients were included; 82% of them (155/189, 95% confidence interval [74-90%]) were correctly classified by the index, while 16 patients were unclassified. Positive predictive ratio was 78% and negative predictive ratio was 86%. Specificity (78%) was not significantly affected by curve location, while patients with thoracic and lumbar curves showed higher sensitivity (≥ 89%) than those with thoracolumbar curves (74%). CONCLUSIONS: In this multicentric cohort of 205 patients, the severity index was used to predict the risk of progression from mild to moderate scoliosis, with similar results of typical major curve types. This index represents a novel tool to aid the clinician and the patient in the modulation of the follow-up and, for progressive patients, their decision for brace treatment. KEY POINTS: • The severity index of adolescent idiopathic scoliosis has the potential to detect patients with progressive scoliosis as early as the first exam. • Out of 205 patients, 82% were correctly classified as either stable or progressive by the severity index. • The location of the main curve had small effect on the predictive capability of the index.

Axial plane characteristics of thoracic scoliosis and their usefulness for determining the fusion levels and the correction technique.

PURPOSE: There is insufficient information regarding axial plane characteristics of scoliosis despite its 3D nature. The posterior-anterior vertebral vector (VV) has been proposed to characterize the axial plane appearances of the thoracic scoliosis. This study aimed to highlight the importance of knowledge of axial plane features when determining fusion levels and correction techniques of thoracic curves. METHODS: Altogether, 233 thoracic curves were analyzed using the VV after proving its usability instead of 3D angles to determine axial plane parameters such as apical vertebral (APV) axial rotations, APV lateral displacement, and intervertebral rotations (IVR). K-means clustering and regression analysis were used to identify axial plane curve patterns and determine the relationship between the coronal angles and axial plane characteristics, respectively. RESULTS: A close correlation was found between 3D angles and VV projected angles. Eight axial plane clusters were distinct, exhibiting different lateral APV displacement toward the interacetabular axis with relatively small axial rotations and a simultaneous decrease in sagittal curves. The regression analysis showed that the correlation of coronal curve magnitude was significantly stronger (r = 0.78) with APV lateral translation than with APV axial rotation (r = 0.65). CONCLUSION: Based on these findings, the primary goal of scoliosis correction should focus on minimizing lateral translation rather than eliminating axial rotation. Knowing the IVR in the axial plane helps accurately determine the limits of the structural curves. VV-based axial views can facilitate the accurate determination of the end vertebrae and selection of the appropriate correction technique of the curve. These slides can be retrieved under Electronic Supplementary Material.

Spino-femoral muscles affect sagittal alignment and compensatory recruitment: a new look into soft tissues in adult spinal deformity.

OBJECTIVE: To quantify muscle characteristics (volumes and fat infiltration) and identify their relationship to sagittal malalignment and compensatory mechanism recruitment. METHODS: Female adult spinal deformity patients underwent T1-weighted MRI with a 2-point Dixon protocol from the proximal tibia up to the T12 vertebra. 3D reconstructions of 17 muscles, including extensors and flexors of spine, hip and knee, were obtained. Muscle volume standardized by bone volume and percentage of fat infiltration (Pfat) were calculated. Correlations and regressions were performed. RESULTS: A total of 22 patients were included. Significant correlations were observed between sagittal alignment and muscle parameters. Fat infiltration of the hip and knee flexors and extensors correlated with larger C7-S1 SVA. Smaller spinal flexor/extensor volumes correlated with greater PI-LL mismatch (r = - 0.45 and - 0.51). Linear regression identified volume of biceps femoris as only predictor for PT (R2 = 0.34, p = 0.005) and Pfat of gluteus minimus as only predictor for SVA (R2 = 0.45, p = 0.001). Sagittally malaligned patients with larger PT (26.8° vs. 17.2°) had significantly smaller volume and larger Pfat of gluteus medius, gluteus minimus and biceps femoris, but similar values for gluteus maximus, the hip extensor. CONCLUSION: This study is the first to quantify the relationship between degeneration of spino-femoral muscles and sagittal malalignment. This pathoanatomical study identifies the close relationship between gluteal, hamstring muscles and PT, SVA, which deepens our understanding of the underlying etiology that contributes to adult spinal deformity.

Quasi-automatic early detection of progressive idiopathic scoliosis from biplanar radiography: a preliminary validation.

PURPOSE: To validate the predictive power and reliability of a novel quasi-automatic method to calculate the severity index of adolescent idiopathic scoliosis (AIS). METHODS: Fifty-five AIS patients were prospectively included (age 10-15, Cobb 16° ± 4°). Patients underwent low-dose biplanar X-rays, and a novel fast method for 3D reconstruction of the spine was performed. They were followed until skeletal maturity (stable patients) or brace prescription (progressive patients). The severity index was calculated at the first examination, based on 3D parameters of the scoliotic curve, and it was compared with the patient's final outcome (progressive or stable). Three operators have repeated the 3D reconstruction twice for a subset of 30 patients to assess reproducibility (through Cohen's kappa and intra-class correlation coefficient). RESULTS: Eighty-five percentage of the patients were correctly classified as stable or progressive by the severity index, with a sensitivity of 92% and specificity of 74%. Substantial intra-operator agreement and good inter-operator agreement were observed, with 80% of the progressive patients correctly detected at the first examination. The novel severity index assessment took less than 4 min of operator time. CONCLUSIONS: The fast and semiautomatic method for 3D reconstruction developed in this work allowed for a fast and reliable calculation of the severity index. The method is fast and user friendly. Once extensively validated, this severity index could allow very early initiation of conservative treatment for progressive patients, thus increasing treatment efficacy and therefore reducing the need for corrective surgery. These slides can be retrieved under Electronic Supplementary Material.

Shear-wave elastography can evaluate annulus fibrosus alteration in adolescent scoliosis.

OBJECTIVES: In vitro studies showed that annulus fibrosus lose its integrity in idiopathic scoliosis. Shear-wave ultrasound elastography can be used for non-invasive measurement of shear-wave speed (SWS) in vivo in the annulus fibrosus, a parameter related to its mechanical properties. The main aim was to assess SWS in lumbar annulus fibrosus of scoliotic adolescents and compare it to healthy subjects. METHODS: SWS was measured in 180 lumbar IVDs (L3L4, L4L5, L5S1) of 30 healthy adolescents (13 ± 1.9 years old) and 30 adolescent idiopathic scoliosis patients (13 ± 2 years old, Cobb angle: 28.8° ± 10.4°). SWS was compared between the scoliosis and healthy control groups. RESULTS: In healthy subjects, average SWS (all disc levels pooled) was 3.0 ± 0.3 m/s, whereas in scoliotic patients it was significantly higher at 3.5 ± 0.3 m/s (p = 0.0004; Mann-Whitney test). Differences were also significant at all disc levels. No difference was observed between males and females. No correlation was found with age, weight and height. CONCLUSION: Non-invasive shear-wave ultrasound is a novel method of assessment to quantitative alteration of annulus fibrosus. These preliminary results are promising for considering shear-wave elastography as a biomechanical marker for assessment of idiopathic scoliosis. KEY POINTS: • Adolescent idiopathic scoliosis may have an altered lumbar annulus fibrosus. • Shear-wave elastography can quantify lumbar annulus fibrosus mechanical properties. • Shear-wave speed was higher in scoliotic annulus than in healthy subjects. • Elastography showed potential as a biomechanical marker for characterizing disc alteration.

Axial plane dissimilarities of two identical Lenke-type 6C scoliosis cases visualized and analyzed by vertebral vectors.

PURPOSE: The global appearance of scoliosis in the horizontal plane is not really known. Therefore, the aims of this study were to analyze scoliosis in the horizontal plane using vertebral vectors in two patients classified with the same Lenke group, and to highlight the importance of the information obtained from these vertebral vector-based top-view images in clinical practice. METHODS: Two identical cases of scoliosis were selected, based on preoperative full-body standing anteroposterior and lateral radiographs obtained by the EOS™ 2D/3D system. Three-dimensional (3D) surface reconstructions of the spinal curves were performed by using sterEOS™ 3D software before and after surgery. In both patients, we also determined the vertebral vectors and horizontal plane coordinates for analyzing the curves mathematically before and after surgery. RESULTS: Despite the identical appearance of spinal curves in the frontal and sagittal planes, the horizontal views seemed to be significantly different. The vertebral vectors in the horizontal plane provided different types of parameters regarding scoliosis and the impact of surgical treatment: reducing lateral deviations, achieving harmony of the curves in the sagittal plane, and reducing rotations in the horizontal plane. CONCLUSIONS: Vertebral vectors allow the evolution of scoliosis curve projections in the horizontal plane before and after surgical treatment, along with representation of the entire spine. The top view in the horizontal plane is essential to completely evaluate the scoliosis curves, because, despite the similar representations in the frontal and sagittal planes, the occurrence of scoliosis in the horizontal plane can be completely different. These slides can be retrieved under Electronic Supplementary Material.

Cervical sagittal alignment variations in adolescent idiopathic scoliosis patients treated with thoraco-lumbo-sacral orthosis.

PURPOSE: Thoraco-lumbo-sacral orthosis (TLSO) is an effective treatment in adolescent idiopathic scoliosis (AIS) patients, but cervical sagittal alignment (CSA) variations after bracing have never been evaluated. The purpose of this study was to assess changes in CSA before, during and after TLSO treatment, and to determine whether patients developed cervical pain. METHODS: This was a retrospective study in 38 AIS patients (33 females; mean age 10.8 years) treated by TLSO. Patients were Risser 0 (n = 34) or 1 (n = 4). Major curve deformity (MC) in the coronal plane and cervical (CSA), thoracic (TSA) and lumbar (LSA) sagittal alignment were evaluated radiographically at start of treatment (t 0), after 1 month of brace treatment (t 1), and 1 year after end of treatment (t 2). Cervical pain was evaluated at t 2 using a visual analogue scale (VAS). RESULTS: The TLSO was worn for an average of 4.6 years. Mean CSA, TSA and LSA were significantly lower at t 2 than at t 0: 0 ± 2.5° vs. 9.4 ± 2.3°, 24.1 ± 2.6° vs. 29.3 ± 2.4° and 5 ± 1.9° vs. 44.2 ± 2.5°, respectively (p < 0.05). CSA and TSA showed moderate-good correlation (r = 0.57). CSA was normolordotic in 1/38 patients at t 2 compared to 18/38 at t 0 (p < 0.05). MC did not progress during treatment (p > 0.8). VAS score was 0 in all patients. CONCLUSIONS: The TLSO can control progression of the deformity in the frontal plane, but it influences CSA, TSA and LSA. In particular, it decreases cervical spine lordosis, with reduction maintained 1 year after the end of treatment. Numerical differences, although statistically significant, were not clinically relevant.

Rod Migration Into the Spinal Canal After Posterior Instrumented Fusion Causing Late-Onset Neurological Symptoms.

BACKGROUND: Rod migration into the spinal canal after posterior instrumented fusion is a rare complication causing late-onset neurological symptoms. The purpose of the present study is to report a case of a 13-year-old boy with spastic cerebral palsy and related neuromuscular kyphoscoliosis who developed late-onset neurological deterioration secondary to progressive implant migration into the spinal canal over a 5-year period. METHODS: A decision was made to remove both rods to achieve decompression. Intraoperative findings were consistent with information gained from preoperative imaging. The rods were found to have an intracanal trajectory at T9-T10 for the right rod and T12-L2 for the left rod. RESULTS: The cause of implant migration, with progressive laminar erosion slow enough to generate a solid mass behind, was progressive kyphosis in a skeletally immature patient with neuromuscular compromise. CONCLUSIONS: Fixation type, early surgery, and spasticity management contributed significantly to the presenting condition. Mechanical factors and timing of surgery played a decisive role in this particular presentation. LEVEL OF EVIDENCE: Level IV--Case report and review of the literature.

The horizontal plane appearances of scoliosis: what information can be obtained from top-view images?

PURPOSE: A posterior-anterior vertebral vector is proposed to facilitate visualization and understanding of scoliosis. The aim of this study was to highlight the interest of using vertebral vectors, especially in the horizontal plane, in clinical practice. METHODS: We used an EOS two-/three-dimensional (2D/3D) system and its sterEOS 3D software for 3D reconstruction of 139 normal and 814 scoliotic spines-of which 95 cases were analyzed pre-operatively and post-operatively, as well. Vertebral vectors were generated for each case. Vertebral vectors have starting points in the middle of the interpedicular segment, while they are parallel to the upper plate, ending in the middle of the segment joining the anterior end plates points, thus defining the posterior-anterior axis of vertebrae. To illustrate what information could be obtained from vertebral vector-based top-view images, representative cases of a normal spine and a thoracic scoliosis are presented. RESULTS: For a normal spine, vector projections in the transverse plane are aligned with the posterior-anterior anatomical axis. For a scoliotic spine, vector projections in the horizontal plane provide information on the lateral decompensation of the spine and the lateral displacement of vertebrae. In the horizontal plane view, vertebral rotation and projections of the sagittal curves can also be analyzed simultaneously. CONCLUSIONS: The use of posterior-anterior vertebral vector facilitates the understanding of the 3D nature of scoliosis. The approach used is simple. These results are sufficient for a first visual analysis furnishing significant clinical information in all three anatomical planes. This visualization represents a reasonable compromise between mathematical purity and practical use.

Lumbar annulus fibrosus biomechanical characterization in healthy children by ultrasound shear wave elastography.

OBJECTIVES: Intervertebral disc (IVD) is key to spine biomechanics, and it is often involved in the cascade leading to spinal deformities such as idiopathic scoliosis, especially during the growth spurt. Recent progress in elastography techniques allows access to non-invasive measurement of cervical IVD in adults; the aim of this study was to determine the feasibility and reliability of shear wave elastography in healthy children lumbar IVD. METHODS: Elastography measurements were performed in 31 healthy children (6-17 years old), in the annulus fibrosus and in the transverse plane of L5-S1 or L4-L5 IVD. Reliability was determined by three experienced operators repeating measurements. RESULTS: Average shear wave speed in IVD was 2.9 ± 0.5 m/s; no significant correlations were observed with sex, age or body morphology. Intra-operator repeatability was 5.0 % while inter-operator reproducibility was 6.2 %. Intraclass correlation coefficient was higher than 0.9 for each operator. CONCLUSIONS: Feasibility and reliability of IVD shear wave elastography were demonstrated. The measurement protocol is compatible with clinical routine and the results show the method's potential to give an insight into spine deformity progression and early detection. KEY POINTS: • Intervertebral disc mechanical properties are key to spine biomechanics • Feasibility of shear wave elastography in children lumbar disc was assessed • Measurement was fast and reliable • Elastography could represent a novel biomarker for spine pathologies.

Serial elongation, derotation and flexion (EDF) casting under general anesthesia and neuromuscular blocking drugs improve outcome in patients with juvenile scoliosis: preliminary results.

PURPOSE: Juvenile scoliosis (JS), among different types of spinal deformity, remains still a challenge for orthopedic surgeons. Elongation, derotation and flexion (EDF) casting technique is a custom-made thoracolumbar cast based on a three-dimensional correction concept. The primary objective of the present study was to measure changes on plain radiographs of patients with JS treated with EDF plaster technique. The second aim was to evaluate the effectiveness of the EDF plaster technique realized under general anesthesia (GA) and neuromuscular blocking drugs, i.e. curare, on the radiological curve correction. METHODS: A retrospective comparative case series study was performed in which were included forty-four skeletally immature patients. Three patient groups were selected. Group 1: EDF cast applied with patients awaken and no anesthesia; Group 2: EDF cast applied under GA without neuromuscular blocking drugs; Group 3: EDF cast applied under GA with neuromuscular blocking drugs. All the patients were treated with two serial EDF casts by 2 months and a half each. All measurements were taken from the radiographic exams. Cobb's angle; RVAD and Nash and Moe grade of rotation were assessed before and after applying the cast. Thirty-four (77.3 %) patients were followed up at least 24 months after removal of last EDF cast. RESULTS: Eighteen patients (3 males, 15 females) were included in Group 1, 12 (2 males, 10 females) in Group 2 and 14 (5 males, 9 females) in Group 3. Serial EDF casting was more effective at initial curve reduction and in preventing curve progression when applied under GA with neuromuscular blocking drugs, i.e. curare. RVAD and Nash and Moe score improved significantly in all groups of patients treated according to principles of EDF technique. During follow-up period, six patients required surgery in Group 1 (6/18; 33.3 %), 3 patients required surgery in Group 2 (3/12; 25 %) and 2 patients underwent surgery in Group 3 (2/14; 15 %). CONCLUSIONS: Preliminary results show EDF casting is effective in controlling the curve in both frontal (Cobb's angle) and transverse plane (rib vertebral angle and apical vertebral rotation degree).

Non-invasive biomechanical characterization of intervertebral discs by shear wave ultrasound elastography: a feasibility study.

OBJECTIVES: Although magnetic resonance is widely spread to assess qualitatively disc morphology, a simple method to determine reliably intervertebral disc status is still lacking. Shear wave elastography is a novel technique that allows quantitative evaluation of soft-tissues' mechanical properties. The aim of this study was to assess preliminary the feasibility and reliability of mechanical characterization of cervical intervertebral discs by elastography and to provide first reference values for asymptomatic subjects. METHODS: Elastographic measurements were performed to determine shear wave speed (SWS) in C6-C7 or C7-T1 disc of 47 subjects; repeatability and inter-operator reproducibility were assessed. RESULTS: Global average shear wave speed (SWS) was 3.0 ± 0.4 m/s; measurement repeatability and inter-user reproducibility were 7 and 10%, respectively. SWS was correlated with both subject's age (p = 1.3 × 10(-5)) and body mass index (p = 0.008). CONCLUSIONS: Shear wave elastography in intervertebral discs proved reliable and allowed stratification of subjects according to age and BMI. Applications could be relevant, for instance, in early detection of disc degeneration or in follow-up after trauma; these results open the way to larger cohort studies to define the place of this technique in routine intervertebral disc assessment. KEY POINTS: A simple method to obtain objectively intervertebral disc status is still lacking. Shear wave elastography was applied in vivo to assess intervertebral discs. Elastography showed promising results in biomechanical disc evaluation. Elastography could be relevant in clinical routine for intervertebral disc assessment.

Use of EOS imaging for the assessment of scoliosis deformities: application to postoperative 3D quantitative analysis of the trunk.

PURPOSE: EOS imaging system is accessible to clinicians since 2007, allowing 3D spinal reconstructions in a functional standing position with reduced radiation. However, numerous ongoing research protocols continuously help implementing the dedicated software. The main principle and applications of the EOS device are discussed here, with an emphasis on future projects. In particular, the authors studied the postoperative modification of the rib cage and spinal morphology after posteromedial correction, in a consecutive series of adolescent idiopathic scoliosis (AIS) patients. METHODS: 49 thoracic AIS patients underwent low-dose stereoradiography preoperatively, postoperatively and at latest examination, with a minimum 2-year follow-up. Spinal and rib cages 3D reconstructions were obtained using dedicated software, and the postoperative modification of thoracic parameters was reported. RESULTS: All parameters were significantly improved after surgery. Mean thoracic volume increase was 8.4% (±8), influenced by the postoperative derotation of the apical vertebra. No difference was found in thoracic volume increase in patients who gained more than 10° of thoracic kyphosis. A significant correlation was found between spinal penetration index at the apex and thoracic sagittal alignment (p = 0.02). CONCLUSIONS: EOS imaging device now reliably provides a global 3D quantitative analysis of scoliotic deformities in a context of routine clinical use. This innovative tool will help in the future to better understand scoliosis physiopathology and to evaluate treatment strategies.

[Can falls be prevented?]. / La prévention des chutes est-elle possible?

Most recommendations and measures intended to prevent falls focus on the elderly (see HAS guideline of April 2009) but, in our opinion, this isfar too late: prevention must begin much earlier, not only by identifying persons at risk, but also by providing personalized lifestyle advice adapted to each individual's biomechanical, somatic, neurological and biological characteristics. The first preventive measure is to identify a possible deterioration of balance, starting with a physical examination at the age of 45 and repeated regularly throughout life. Extrinsic preventive measures focusing on the domestic and external environments are clearly necessary. But what is most important is to detect and, if necessary, correct any degradation of intrinsic (intracorporeal or somatic) factors starting at the age of 45 years; these include vision, vestibular function and balance, proprioception, and psychological and neurological status. Chronic illnesses and their treatments must also be taken into account: treatment must be limited to indispensable drugs; sedative psychotropics must be avoided if possible; and polymedication must be tightly controlled, as it is a major risk factor for falls. Prevention also requires a diet sufficiently rich in protein, calcium and vitamin D3 (to prevent osteoporosis), and regular daily exercise adapted to the individual, if possible associated with a simultaneous cognitive task. The last key point is the absolute need for thorough functional rehabilitation after any accidental or medical trauma, regardless of age, with the aim of restoring functional status to that existing prior to the accident.