Age- and Gender-based Global Sagittal Spinal Alignment in Asymptomatic Adult Volunteers: Results of the Multiethnic Alignment Normative Study (MEANS).

Study Design: Multicenter Cohort.

Objective: Assess normative values of sagittal spinal and lower extremity alignment in asymptomatic volunteers stratified by age and gender.

Summary Of Background Data: Our understanding of ideal sagittal alignment is still evolving.

Age and Gender Based Spinopelvic and Regional Spinal Alignment in Asymptomatic Adult Volunteers: Results of the Multi-Ethnic Alignment Normative Study (MEANS).

Background: Spinal alignment can have a significant impact on a patient's overall quality of life. Predicting the ideal sagittal spinal alignment of a specific individual is still a difficult task. The Multi-Ethnic Alignment Normative Study (MEANS) investigated skeletal alignment, including the spine and lower extremities, of the largest multi-ethnic cohort of asymptomatic adult volunteers.

Correlation analysis of the PI-LL mismatch according to the pelvic incidence from a database of 468 asymptomatic volunteers.

Purpose: Previous studies on adults with degenerative scoliosis (ADS) have been fixed the threshold of PI-LL mismatch less than 10° for achieving good clinical outcomes. Recent studies discussed that PI-LL mismatch should consider individual pelvic incidence (PI) and should be set first in a normal population. The purpose of this study is to assess the variability of PI-LL mismatch according to PI in an asymptomatic population.

Pelvic thickness, sex, ethnicity, and age affect pelvic incidence in healthy volunteers of Multi-Ethnic Alignment Normative Study (MEANS) database.

Background: The purpose of this study was to investigate the affecting factors on pelvic incidence (PI) and to test the hypothesis that PI changes even after skeletal maturity probably due to hypermobility of the sacroiliac joint using a large international multi-center database.

Methods: A prospective and cross-sectional healthy adult volunteers, ages 18-80 years, across 5 countries were used. Radiographic measurements included standard whole body alignment parameters.

The Contribution of Deleterious Rare Alleles in ENPP1 and Osteomalacia Causative Genes to Atypical Femoral Fracture.

Context: Atypical femoral fractures (AFFs) are very rare atraumatic or mild trauma fractures in the subtrochanteric region or femoral shaft. Some unique genetic variants in Asian populations might confer susceptibility to AFF, since the incidence of AFFs is higher in Asian populations.

Objective: Because rare variants have been found to be causative in some diseases and the roles of osteomalacia causative genes have not been reported, we investigated rare variants in genes causing abnormal mineralization.

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-mm 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.

Impact of the flexibility of the spinal deformity on low back pain and disc degeneration in adult patients nonoperatively treated for adolescent idiopathic scoliosis with thoracolumbar or lumbar curves.

Purpose: To evaluate the impact of the flexibility of thoracolumbar or lumbar (TL/L) curves on low back pain (LBP) and disc degeneration in adult patients nonoperatively treated for adolescent idiopathic scoliosis (AIS).

Methods: Forty-seven adult patients (46 women; mean age, 40.5 years) nonoperatively treated for AIS with TL/L curves were included.

The odontoid-CSVL distance in a global population of asymptomatic volunteers: normative values and implications for spinal coronal alignment.

Purpose: In a population of asymptomatic volunteers across 5 countries, we sought to: (a) establish normative values of the Odontoid-Central Sacral Vertical Line (OD-CSVL) across patient factors, and (b) assess correlations of OD-CSVL with other radiographic parameters.

Methods: A prospective, cross-sectional study of asymptomatic adult volunteers, ages 18-80 years, were enrolled across 5 countries (France, Japan, Singapore, Tunisia, United States) forming the Multi-Ethnic Alignment Normative Study (MEANS) cohort. Included volunteers had no known spinal disorder(s), no significant neck/back pain (VAS ≤ 2; ODI ≤ 20), and no significant scoliosis (Cobb ≤ 20°).

Longer Screws Can Reduce the Stress on the Upper Instrumented Vertebra With Long Spinal Fusion Surgery: A Finite Element Analysis Study.

Study Design: A finite element analysis study.

Objective: Of proximal junctional failure, upper instrumented vertebra (UIV) fracture can causes severe spinal cord injury. Previously, we reported that higher occupancy rate of pedicle screw (ORPS) at UIV prevented UIV fracture in adult spinal deformity surgery; we had not yet tested this finding using a biomechanical study.

Influence of lumbosacral transitional vertebrae on spinopelvic parameters using biplanar slot scanning full body stereoradiography-analysis of 291 healthy volunteers.

Background: Proper identification of lumbosacral transitional vertebrae (LSTV) is important to characterize the relationship between the transitional segment and adjacent levels. Classical classification schemes are inaccurate with respect to the whole spine. We propose a precise vertebral numbering method and investigated the relationship between LSTV and whole-body sagittal alignment.

Sacral incidence to pubis: a novel and alternative morphologic radiological parameter to pelvic incidence in assessing spinopelvic sagittal alignment.

Background: Although pelvic incidence (PI) is a key morphologic parameter in assessing spinopelvic sagittal alignment, accurate measurements of PI become difficult in patients with severe hip dislocation or femoral head deformities. This study aimed to investigate the reliability of our novel morphologic parameters and the correlations with established sagittal spinopelvic parameters.

Methods: One hundred healthy volunteers (25 male and 75 female), with an average age of 38.

Significance of long corrective fusion to the ilium for physical function in patients with adult spinal deformity.

Background: We aimed to investigate the impact of long corrective fusion to the ilium on the physical function in elderly patients with adult spinal deformity and its correlation with spinopelvic parameters and health-related quality of life outcomes.

Methods: We included 60 female patients who underwent long corrective fusion from T9 or T10 to the pelvis for adult spinal deformities (mean age of 69.8 years, range 55-78 years).

Compensation for standing posture by whole-body sagittal alignment in relation to health-related quality of life.

Aims: The aim of this study is to test the hypothesis that three grades of sagittal compensation for standing posture (normal, compensated, and decompensated) correlate with health-related quality of life measurements (HRQOL).

Methods: A total of 50 healthy volunteers (normal), 100 patients with single-level lumbar degenerative spondylolisthesis (LDS), and 70 patients with adult to elderly spinal deformity (deformity) were enrolled. Following collection of demographic data and HRQOL measured by the Scoliosis Research Society-22r (SRS-22r), radiological measurement by the biplanar slot-scanning full body stereoradiography (EOS) system was performed simultaneously with force-plate measurements to obtain whole body sagittal alignment parameters.

Posterior bone graft in lumbar spine surgery reduces the stress in the screw-rod system- A finite element study.

Purpose: Analyze the biomechanical effect of postero-lateral instrumentation with and without posterior bone graft as well as effect of consolidation of the graft. Study objectives are (1) whether bone graft alone will provide enough additional strength to the weakened spine, (2) how the addition of posterior bone graft help in extending the life of the fusion construct, and (3) compare the effect of gradual consolidation of the bone-graft on the spine biomechanics.

Methods: A lumbar spine finite element model was used to analyze the effects of bone-graft alone and varying grades of bone-graft consolidation with postero-lateral instrumentation on spine biomechanics.

Etiology and clinical manifestations of double-level versus single-level lumbar degenerative spondylolisthesis.

Background: The differences in etiology, clinical manifestation, and whole body standing alignment between single-level LDS (sLDS) and double-level LDS (dLDS) have not been sufficiently clarified. We hypothesized that the etiology and manifestations of dLDS differ from those of sLDS. This study aimed to test this hypothesis.

Flexibility of the thoracic curve and three-dimensional thoracic kyphosis can predict pulmonary function in nonoperatively treated adult patients with adolescent idiopathic scoliosis.

Background: Although several radiographic predictors for pulmonary function in adolescent patients have been reported, those in adult patients remain unclear. Therefore, we aimed to investigate the associations between spinal deformity and pulmonary function in nonoperatively treated adult patients with adolescent idiopathic scoliosis (AIS).

Methods: Of 319 patients treated nonoperatively for AIS, 90 (average age, 40.

Long-term Impacts of Brace Treatment for Adolescent Idiopathic Scoliosis on Body Composition, Paraspinal Muscle Morphology, and Bone Mineral Density.

Study Design: A retrospective, long-term follow-up study.

Objective: We aimed to investigate the long-term impacts of brace treatment for adolescent idiopathic scoliosis (AIS) on the musculoskeletal system.

Summary Of Background Data: Although full-time brace treatment is the mainstay of conservative treatment for AIS, the restrictive nature of brace treatment for lumbosacral motion might negatively affect the musculoskeletal system.

Can posterior implant removal prevent device-related vertebral osteopenia after posterior fusion in adolescent idiopathic scoliosis? A mean 29-year follow-up study.

Purpose: To determine whether posterior implant removal prevents stress-shielding-induced vertebral osteopenia within the posterior fusion area in surgically treated patients with adolescent idiopathic scoliosis (AIS).

Methods: Eighteen patients with major thoracic AIS (mean age, 43.3 years; range, 32-56 years; mean follow-up, 28.

Difference in whole spinal alignment between supine and standing positions in patients with adult spinal deformity using a new comparison method with slot-scanning three-dimensional X-ray imager and computed tomography through digital reconstructed radiography.

Background: A precise comparison of supine and standing whole spine alignment in both the coronal and sagittal planes, including the pelvic parameters, has not been reported. Furthermore, previous studies investigated positional differences in the Cobb angle only in young patients with idiopathic scoliosis. The difference in alignment has never been investigated in a population of patients with adult spinal deformity (ASD).

En Bloc Spondylectomy for Spinal Metastases: Detailed Oncological Outcomes at a Minimum of 2 Years after Surgery.

Study Design: Retrospective case series.

Purpose: To investigate the oncological outcomes, including distant relapse, after en bloc spondylectomy (EBS) for spinal metastases in patients with a minimum of 2-year follow-up.

Overview Of Literature: Although EBS has been reported to be locally curative and extend survival in select patients with spinal metastases, detailed reports regarding the control of distant relapse after EBS are lacking.

Predicting Factors at Skeletal Maturity for Curve Progression and Low Back Pain in Adult Patients Treated Nonoperatively for Adolescent Idiopathic Scoliosis With Thoracolumbar/Lumbar Curves: A Mean 25-year Follow-up.

Study Design: A retrospective, long-term follow-up study.

Objective: We aimed to clarify the predicting factors at skeletal maturity for future curve progression and low back pain (LBP) in adolescent idiopathic scoliosis (AIS) with thoracolumbar/lumbar (TL/L) curve.

Summary Of Background Data: TL/L curves are likely to progress after skeletal maturity and cause LBP.

The Influence of Lumbar Muscle Volume on Curve Progression After Skeletal Maturity in Patients With Adolescent Idiopathic Scoliosis: A Long-Term Follow-up Study.

Study Design: A retrospective cohort study.

Objectives: To investigate the relationship between skeletal muscle status of the trunk and the progression of adolescent idiopathic scoliosis (AIS) during adulthood.

Summary Of Background Data: To date, studies evaluating the risk factors for progression of AIS have principally focused on radiographic parameters.

Relationship between sagittal radiographic parameters and disability in patients with spinal disease using 3D standing analysis.

Purpose: To clarify the relationship between whole body sagittal radiographic parameters and health related quality of life (HRQOL) in patients with spinal disease, and further analyse such relationship based on the pelvic incidence (PI) value.

Methods: 100 patients (mean age: 64.4 years, M/F=50/50) with lumbar degenerative disease or spinal deformity were prospectively investigated.