Sex-dependent evolution of whole-body postural alignment with age.

PURPOSE: The goal of this study was to explore sex-related variations of global alignment parameters and their distinct evolution patterns across age groups. METHODS: This multicentric retrospective study included healthy volunteers with full-body biplanar radiographs in free-standing position. All radiographic data were collected from 3D reconstructions: global and lower limb parameters, pelvic incidence (PI) and sacral slope (SS). Lumbar lordosis (LL), thoracic kyphosis (TK) and cervical lordosis (CL) were also assessed as well as the lumbar and thoracic apex, and thoracolumbar inflexion point. The population was divided into five 5 age groups: Children, Adolescents, Young, Middle-Aged and Seniors. RESULTS: This study included 861 subjects (53% females) with a mean age of 34 ± 17 years. Mean PI was 49.6 ± 11.1 and mean LL was - 57.1 ± 11.6°. Females demonstrated a PI increase between Young and Middle-Aged groups (49 ± 11° vs. 55 ± 12°, p < 0.001) while it remained stable in males. SS and LL increased with age in females while remaining constant in males between Children and Middle-aged and then significantly decreased for both sexes between Middle-Aged and Seniors. On average, lumbar apex, inflexion point, and thoracic apex were located one vertebra higher in females (p < 0.001). After skeletal maturity, males had greater TK than females (64 ± 11° vs. 60 ± 12°, p = 0.04), with significantly larger CL (-13 ± 10° vs. -8 ± 10°, p = 0.03). All global spinal parameters indicated more anterior alignment in males. CONCLUSION: Males present more anteriorly tilted spine with age mainly explained by a PI increase in females between Young and Middle-Aged, which may be attributed to childbirth. Consequently, SS and LL increased before decreasing at senior age.

The effect of Providence night-time bracing on the sagittal profile in adolescent idiopathic scoliosis.

PURPOSE: Adolescent idiopathic scoliosis (AIS) is characterized by coronal scoliosis and often a sagittal hypokyphosis. The effect of bracing on the sagittal profile is not well understood. The aim of this study is to assess the effect of night-time bracing on the sagittal profile in patients with AIS. METHODS: We retrospectively included AIS patients with a main curve of 25-45° treated with a night-time brace in our institution between 2005 and 2018. Patients with estimated growth potential based on either Risser stage, hand X-rays, or menarchal status were included. Coronal and sagittal radiographic parameters were recorded at both brace- initiation and -termination. Patients were followed until surgery or one year after brace termination. Results were compared to a published cohort of full-time braced patients. RESULTS: One hundred forty-six patients were included. Maximum thoracic kyphosis (TK) increased 2.5° (± 9.7) (p = 0.003), corresponding to a 3.5-fold relative risk increase post bracing in TK compared to a full-time brace cohort. Twenty-seven percent (n = 36) of the patients were hypokyphotic (T4/T12 < 20°) at brace initiation compared with 19% (n = 26) at brace termination (p = 0.134). All other sagittal parameters remained the same at follow-up. We found no association between progression in the coronal plane and change in sagittal parameters. CONCLUSION: This is the first study to indicate that night-time bracing of AIS does not induce hypokyphosis. We found a small increase in TK, with a substantially lower risk of developing flat back deformity compared to full-time bracing. The coronal curve progression was not coupled to a change in TK.

Estimating thoracic kyphosis without information on upper thoracic kyphosis: an observational study on 455 patients examined by EOS imaging.

BACKGROUND: Physiological thoracic kyphosis (TK) allows sagittal balance of human body. Unlike lumbar lordosis (LL), TK has been relatively neglected in the literature. EOS is an imaging technique employing high-sensitivity xenon particles, featured by low-dose exposure combined with high accuracy compared to conventional radiography. The aim of this study was to investigate predictors of TK in patients with phyiological spine morphology using EOS imaging. METHODS: EOS images of 455 patients without spinal anomalies were retrospectively assessed for TK (T1- T12), upper thoracic kyphosis (UTK, T1-T5), lower thoracic kyphosis (LTK, T5-T12), LL (L1-S1) and pelvic incidence (PI). The latter curves were measured by two researchers separately and the average of the two measurements was used for further analysis. Spearman non-parametric correlation was estimated for age, PI, LL, LTK, UTK and TK. Multiple robust linear regression analysis was employed to estimate TK, controlling for the effect of age, sex, LL and LTK. RESULTS: The mean age of patients was 28.3 ± 19.2 years and 302 (66.4%) of them were females. The mean TK, UTK and LTK was 45.5° ± 9.3, 16 ± 7.4° and 29.7° ± 8.9, respectively. The mean UTK in people under 40 years of age was 17.0° ± 7.2, whereas for patients 40+ years old it was 13.6° ± 7.4. At univariable analysis TK positively correlated with UTK (p<0.001), LTK (p<0.001) an LL (p<0.001). At multivariable linear regression TK increased with LTK (RC = 0.67; 95%CI: 0.59; 0.75) or LL (RC = 0.12; 95%CI: 0.06; 0.18), whereas it decreased with age (RC = -0.06; 95%CI: -0.09;-0.02). CONCLUSION: If EOS technology is available, the above linear regression model could be used to estimate TK based upon information on age, sex, LL and LTK. Alternatively, TK could be estimated by adding to LTK 17.0° ± 7.4 for patients < 40 years of age, or 13.6° ± 7.4 in patients 40 + years old. The evidence from the present study may be used as reference for research purposes and clinical practice, including spine examination of particular occupational categories or athletes.

Restoration of thoracic kyphosis in adolescent idiopathic scoliosis with patient-specific rods: did the preoperative plan match postoperative sagittal alignment?

PURPOSE: To determine if the planned sagittal profile for thoracic kyphosis (TK) restoration was achieved after adolescent idiopathic scoliosis (AIS) surgery using a novel hybrid construct with apical double bands and precontoured patient-specific rods (PSR) made according to the detailed surgical plan for the desired sagittal plane. METHODS: AIS patients with a Lenke type 1-4 primary right thoracic curve who underwent corrective surgery by a single surgeon and had minimum 24-month follow-up were analyzed retrospectively from a prospective database. All patients underwent simultaneous translation on two rods with apical double bands and PSR. Clinical outcomes in terms of sagittal 2D TK (T4-T12), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), PI-LL mismatch, rod angle, and rod deflection were compared between preoperative, planned, and 24-month data, while 3D apical rotation, 3D TK (T5-T12), sagittal thoracolumbar angle, degree of curvature at L1-L4 and L4-S1, proximal junctional angle, and distal junctional angle were compared at baseline and at 6 and 24 months postoperatively. SRS-22 questionnaire scores were obtained at baseline and 24 months postoperatively. RESULTS: Forty-eight patients were included. Study patients had a median coronal thoracic curve of 62.7° preoperatively and 22.4° at 24-month follow-up (p < 0.001). Median TK gain was 6.5° for the entire cohort (n = 48) and 19.1° in the Lenke type 1 and 2 hypokyphotic subgroup (n = 14). Both groups had no significant changes between planned and 24-month TK (p = 0.068 and p = 0.943, respectively), rod angle (p = 0.776 and p = 0.548, respectively), or rod deflection (p = 0.661 and p = 0.850, respectively). For the overall study cohort, median LL gain was 7.0° (p < 0.001), 3D apical derotation was 10.7° (p < 0.001), and change in 3D TK was 36° (p < 0.001). No instance of proximal junctional kyphosis was observed. SRS-22 scores for pain, self-image, and satisfaction differed significantly between the preoperative and 24-month follow-up time-points. CONCLUSIONS: With sagittal plane planning, desired TK, improved reciprocal changes in LL, and minimal changes in rod shape can be achieved in patients with AIS.

Domino connector for thoracic pedicle subtraction osteotomy reduction: surgical technique and patient series.

PURPOSE: Different techniques have been previously described to close the pedicle subtraction osteotomy (PSO) site for correction of sagittal malalignment; the use of a side-to-side domino connector as a correction tool in the thoracic spine has not been specifically studied. METHODS: Twenty adult patients who underwent single-level thoracic PSO from T1 to T12 were included and retrospectively reviewed (two centers). Preoperative and postoperative full-body X-rays, perioperative data, clinical data and complications were recorded with a minimum 2 years of follow-up. Surgical technique and the nuances in using the domino connector were described in detail. RESULTS: Patients had a mean age of 40y; 40% were female. Two different techniques involving the domino were applied for closure of the PSO site depending on the type of kyphosis (smooth vs. angular deformity). Both techniques provided significant correction of the local kyphosis (from 48° to 18°) with reciprocal reduction of compensatory cervical lordosis (from 37.6° to 18.6°, p < 0.01) in upper thoracic PSO or lumbar lordosis (from 74.5° to 46.6°, p < 0.01) in lower thoracic PSO. Four patients presented postoperative complications that resolved (hemothorax, GI bleeding), and two patients presented transient neurological deficit. Oswestry Disability Index score improved in the majority of the patients (from 32.7 to 22.5, p < 0.05). There were no pseudarthroses, symptomatic instrumentation breakage, or surgical site infection. CONCLUSION: Use of a side-to-side domino connector in combination with two different rod cantilever techniques is effective for the reduction of thoracic pedicle subtraction osteotomy achieving satisfactory radiological and clinical outcome.

Predicting thoracic kyphosis morphology and the thoracolumbar inflection point determined by individual lumbar lordosis in asymptomatic adults.

PURPOSE: The aims of this study were to explore the correlations between thoracic kyphosis (TK) and lumbar lordosis (LL) parameters and to build corresponding linear regressions to predict TK morphology and the thoracolumbar inflection point (IP) determined by individual LL parameters in asymptomatic adults. METHODS: A total of 280 adult healthy volunteers were recruited, and full-spine X-rays were performed for each subject in a standing posture. The following sagittal parameters were measured: cumulative TK, LL, proximal LL (PLL), the apices of TK (TKA) and LL (LLA), the IP and the distance from the plumb line of the thoracic apex (TAPL) and the lumbar apex (LAPL) to the gravity line. The correlations between TK and LL parameters were analyzed, and the corresponding linear regressions were conducted. RESULTS: Extensive variations existed in TK alignment, including angular and morphological parameters. In addition, there were statistical correlations of all cumulative TK angles with LL (r values from - 0.173 to - 0.708) and PLL (r values from - 0.206 to - 0.803), TKA and IP with LLA (rs = 0.359 and 0.582, respectively) and TAPL with LAPL (rs = 0.335). The common predictive formulas employed in ASD surgery could include T10-L1 = - 3.6-0.2*LL (R2 = 0.201), T4-L1 = 3.4-0.5*LL (R2 = 0.457), TKA = - 10.3 + 1.1*LLA (R2 = 0.180) and IP = - 12.7 + 1.6*LLA (R2 = 0.330). CONCLUSION: There were intimate associations between TK and LL parameters in asymptomatic adults. Moreover, predictive models for thoracic alignment, particularly cumulative TK, based on LL parameters were proposed, which could better delineate anatomical relationships, guide thoracic construction during adult spinal deformity surgery and may help preventing proximal junctional failure.

Intermittent pedicle screw application provides better kyphosis restoration in adolescent idiopathic scoliosis for Lenke type 1 and type 2 curves.

PURPOSE: There is still no consensus on the optimum pedicle screw density required for the desired thoracic kyphosis restoration in adolescent idiopathic surgery (AIS). The aim of this study to evaluate the effect of pedicle screw density on thoracic kyphosis restoration in AIS surgery. METHODS: The data of 106 patients from two centers that operated for Lenke type 1 and 2 AIS were retrospectively reviewed. Two groups were constituted according to the pedicle screw density: intermittent pedicle screw constructs (IPSC) (n = 52 patients) and consecutive pedicle screw construct (CPSC) (n = 54 patients) groups. The preoperative and at least 24-month follow-up radiographs and SRS-22 scores were evaluated. The Cobb angle of the main and concomitant curves in the coronal plane and the sagittal plane were measured and compared. RESULTS: The mean follow-up period for the IPSC and CPSC groups was 72.3 ± 37.2 and 62.9 ± 28.8 months, respectively. In the SRS-22 questionnaire, there was no significant difference between the two groups in terms of self-image/appearance domain scores (p = 0.466), but better results were obtained in the IPSC group in terms of treatment satisfaction domain scores (p = 0.010) and better thoracic kyphosis restoration was achieved in IPSC group radiologically for Lenke type 1 curves with - 81.4 ± 81.4% in the IPSC group and 6.8 ± 83.8% in the CPSC group (p < 0.001). CONCLUSION: It was considered that better thoracic kyphosis restoration could be achieved with the less lordotic effect of IPSC in Lenke type 1 curves. Although the current situation had a significant impact on radiological outcomes, its effect on SRS-22 scores was limited.

Comparison of four correction techniques for posterior spinal fusion in adolescent idiopathic scoliosis.

INTRODUCTION: When performing posterior spinal fusion for adolescent idiopathic scoliosis (AIS), it is of major importance to address both coronal and sagittal deformities. Although several techniques have been described, few data exist comparing them. Our objective was to compare four techniques (in situ bending (ISB), rod derotation (RD), cantilever (C) and posteromedial translation (PMT)) for the correction of spinal deformity in AIS including thoracic deformity. MATERIAL AND METHODS: We conducted a multicenter retrospective study including 562 AIS patients with thoracic deformity with at least 24-month follow-up. Radiographic analysis was performed preoperatively, postoperatively and at last follow-up. The main outcomes were main curve correction and thoracic kyphosis restoration (TK). RESULTS: Coronal correction rate was significantly different among the four treatment groups (ISB 64% vs C 57% vs RD 55% vs PMT 67%, p < 0.001). Multivariate regression revealed that correction technique did not influence correction rate, whereas implant density, convex side compression and use of derotation connectors did. TK increase was significantly higher in the PMT group (average + 13°) than in DR (+ 3°), while ISB (-3°) and cantilever (-13°) resulted in TK decrease (p < 0.001). Multivariate analysis revealed that TK increase was only influenced by the reduction technique (p < 0.001) and preoperative TK (p < 0.001). DISCUSSION: The four techniques had the same ability to correct spinal deformity in the coronal plane. Three factors were identified to improve correction rate: implant density, convex compression and use of derotation connectors. On the other hand, PMT was more effective in restoring TK, particularly in hypokyphotic patients.

Association between sagittal spinal alignment and postoperative shoulder range of motion following reverse total shoulder arthroplasty.

BACKGROUND: The range of internal rotation sometimes deteriorates after reverse total shoulder arthroplasty; however, the underlying mechanisms remain unclear. This study aimed to investigate the association between sagittal spinal alignment and internal rotation deterioration after reverse total shoulder arthroplasty. METHODS: We retrospectively reviewed 52 patients who underwent reverse total shoulder arthroplasty by a single surgeon between October 2014 and December 2018. The sagittal spine was radiographed, and the sagittal spinal alignment was evaluated based on 10 parameters (e.g. C7-HA: the distance between the plumb line from the center of the seventh cervical vertebral body and the center of the hip axis). We divided the patients into two groups, group A (internal rotation deterioration; 23 patients) and B (without internal rotation deterioration; 29 patients). Logistic regression analysis was performed to analyze the association between sagittal spinal alignment and internal rotation deterioration after reverse total shoulder arthroplasty, and a receiver operating characteristic curve was used to analyse the cutoff value of independent variables that was correlated with IR deterioration. RESULTS: Logistic regression analysis demonstrated the correlation between C7-HA and internal rotation deterioration (odds ratio, 1.95; 95% confidence interval, 1.33-2.84; P < 0.001). The receiver operating characteristic curve suggested that when C7-HA was at least 2.44 cm, it was strongly correlated with deterioration of internal rotation (sensitivity, 91.3%; specificity, 93.1%; P < 0.001; area under the curve, 0.938). Group A was significantly inferior to group B in not only internal rotation but also flexion and abduction. CONCLUSIONS: This study suggested that a remarkably positive value in C7-HA was a factor that was correlated with deterioration of internal rotation. In addition, the deformation of sagittal spinal alignment would impact on the range of motion after reverse total shoulder arthroplasty.

Computer-Aided Diagnosis for Determining Sagittal Spinal Curvatures Using Deep Learning and Radiography.

Analyzing spinal curvatures manually is time-consuming and tedious for clinicians, and intra-observer and inter-observer variability can affect manual measurements. In this study, we developed and evaluated the performance of an automated deep learning-based computer-aided diagnosis (CAD) tool for measuring the sagittal alignment of the spine from X-ray images. The CAD system proposed here performs two functions: deep learning-based lateral spine segmentation and automatic analysis of thoracic kyphosis and lumbar lordosis angles. We utilized 322 datasets with data augmentation for learning and fivefold cross-validation. The segmentation model was based on U-Net, which has multiple applications in medical image processing. Here, we utilized parameter equations and trigonometric functions to design spinal angle measurement algorithms. The kyphosis (T4-T12) and lordosis angle (L1-S1, L1-L5) were automatically measured to help diagnose kyphosis and lordosis. The segmentation model had precision, sensitivity, and dice similarity coefficient values of 90.53 ± 4.61%, 89.53 ± 1.8%, and 90.22 ± 0.62%, respectively. The performance of the CAD algorithm was also verified with the Pearson correlation, Bland-Altman, and intra-class correlation coefficient (ICC) analysis. The proposed angle measurement algorithm exhibited high similarity and reliability during verification. Therefore, CAD can help clinicians in reaching a diagnosis by analyzing the sagittal spinal curvatures while reducing observer-based variability and the required time or effort.

Mid and lower thoracic kyphosis changes during adulthood: the influence of age, sex and thoracic coronal curvature.

INTRODUCTION: There is conflicting data on how thoracic kyphosis changes throughout adulthood. We evaluated mid and lower thoracic kyphosis (MTK) in various age groups and the influence of age, sex and coronal curve (CC) on MTK. MATERIAL AND METHODS: We studied 1323 patients 15-80 years-old (54.4% females) previously evaluated with chest radiographs. We established three groups: patients 15-40 (group 1); 41-60 (group 2) and 61-80 years old (group 3). MTK (T5-T12) and CC were measured using Cobb's method. We established differences in MTK between groups using ANOVA with Bonferroni correction. We performed a correlation analysis of MTK with age and CC, and a linear regression analysis to determine if age, sex and CC independently predicted MTK. RESULTS: MTK increased with older age: mean MTK group 1 = 23.4°; group 2 = 27.9° and group 3 = 34.4°, p < 0.01. The increase in MTK was observed in both genders. Scoliosis was more common in females (15.4%) than in males (6.7%), p < 0.01. MTK was correlated with age (r = 0.4; p < 0.01) and slightly correlated with CC (r = 0.07, p < 0.01). MTK was larger in females than in males (29.1° vs. 27.6°, p < 0.01). Age (ß-coefficient = 0.26) and CC (ß-coefficient = 0.14), but not sex, independently influenced MTK in the regression analysis. CONCLUSION: MTK increases with advancing age during adulthood in both genders; CC, but not sex, was an independent predictor of MTK.

[Impact of the aged-related changes of sagittal spinal curvature on pelvic organ prolapse. A systematic review of the literature]. / Impact des modifications des courbures vertébrales sagittales liées à l'âge sur les prolapsus des organes pelviens. Une revue systématique de la littérature.

OBJECTIVES: The aim of this review was to specify the potential association between age-related changes in sagittal spinal curvature and risk of pelvic organ prolapse in women. METHODS: A systematic review based on the PRISMA statement was performed. Keywords were chosen according to the eligibility criteria in line with the PICO model. For inclusion, studies had to be based on observational cohorts, case controls and cross sectional studies. The quality of the articles was assessed using the STROBE scale. RESULTS: Five papers from 1996 to 2021 were included in the present review with conflicting results. Four studies reported a positive association between anatomical pelvic organ prolapse at clinical examination, a loss of lumbar lordosis and an increase in thoracic kyphosis. The remaining study, using a questionnaire-based assessment of symptoms, found no association between prolapse-related symptoms and age-related changes in sagittal spinal curvatures. CONCLUSION: Based on the available evidence, this systematic review suggested a very moderate evidence of association between the development of anatomical pelvic organ prolapse and age-related changes in sagittal spinal curvature in women. This review remains very limited by the small number and the heterogeneity of the studies included. Further studies in the lifetime continunm, with high quality methodology are needed to better understand the physiopathology of pelvic organ prolapse.

Revisiting thoracic kyphosis: a normative description of the thoracic sagittal curve in an asymptomatic population.

PURPOSE: Thoracic kyphosis (TK) remained in the shadow of lumbar lordosis. Based on Berthonnaud and Roussouly segmentation, TK is divided into two arches: upper TK (UTK) and lower TK (LTK). The purpose of this study is to propose a normative description of the TK arches in an asymptomatic adults' population and their correlation with spinal and pelvic parameters. METHODS: This is an observational study performed on asymptomatic healthy Caucasians volunteers aged between 18 and 45 years. Each patient had a standardized standing biplanar full spine X-rays. Using KEOPS®, sacropelvic parameters and global spinal parameters (LL, TK) as well as the inflexion point location were measured. The upper lumbar lordosis angle (ULL) as well as LTK and UTK was calculated. Patients were classified according to Roussouly morphotypes of normal spine. RESULTS: A total of 373 adults (F/M = 1.4/1) were enrolled with mean age of 27 years. Mean UTK averaged 25.8°, while mean LTK averaged 19.8° (p < 0.001). UTK angle values were statistically the same in the five different Roussouly spinal shapes (p > 0.05), while LTK values were variable among different Roussouly spine subtypes (p < 0.05). Finally, TK showed the highest correlation with the LL mainly with the ULL (Pearson = 0.66). CONCLUSION: In asymptomatic young adults, thoracic kyphosis is composed by two unequal arches, a stable UTK and a variable LTK, with an apex around T8 and T9 vertebra, depending on the spinal morphotype according to Roussouly classification. This should be taken into consideration when analyzing spine sagittal compensation and preparing corrections to minimize risk of mechanical complications.

Proximal junctional kyphosis is a rebalancing spinal phenomenon due to insufficient postoperative thoracic kyphosis after adolescent idiopathic scoliosis surgery.

PURPOSE: Many authors tried to explain proximal junctional kyphosis (PJK) after adolescent idiopathic scoliosis (AIS) surgery by looking for risk factors. Latest publications focus on sagittal alignment. Each healthy adolescent has a specific thoracic kyphosis (TK) depending on their pelvic parameters and lumbar lordosis (LL). The objective of this work is to determine if the difference between TK at follow-up (TKFU) and the patient-specific TK (PSTK) plays a role in PJK occurrence after AIS surgery. The secondary objective was to find other risk factors. METHODS: We analyzed retrospectively 570 thoracic AIS who underwent a posterior thoracic fusion from nine centers. The series was separated in two groups: with and without PJK. PSTK was calculated with the formula PSTK = 2(PT + LL-PI). TK Gap was the difference between TKFU and PSTK. Logistic regression was utilized to test the impact of TK Gap and other known risk factors on PJK occurrence. RESULTS: Univariate analysis showed 15 factors significantly different between the groups. In a multivariate analysis, three factors had a strong significant influence on PJK: TKFU, TK Gain and TK Gap. Four additional factors affected the rate of PJK: Posterior translation on two rods, preoperative TK, preoperative LL and number of instrumented vertebrae. CONCLUSION: PJK is related to the insufficient TK at follow-up, compared to the specific TK that every patient should have according to their pelvic parameters. PJK incidence is significantly reduced by a strong gain in TK and a thoracic selective fusion which leaves the proximal lumbar vertebrae free. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Surgical increase in thoracic kyphosis predicts increase of cervical lordosis after thoracic fusion for adolescent idiopathic scoliosis.

PURPOSE: The modification of cervical lordosis (CL) after adolescent idiopathic scoliosis (AIS) surgery is influenced by the correction of thoracic hypokyphosis. The quantification of the increase of CL as a function of the increase of thoracic kyphosis (TK) has never been calculated. METHODS: A total of 92 consecutive AIS patients who underwent a posterior thoracic selective fusion, corrected by simultaneous translation on 2 rods technique, with minimum 24-month follow-up, were analyzed from a prospective database. We evaluated global sagittal kyphosis and lordosis. CL was divided by the horizontal line in proximal (PCL) and distal cervical lordosis (DCL), likewise TK in proximal (PTK) and distal TK (DTK), and lumbar lordosis (LL) in proximal (PLL) and distal LL (DLL). RESULTS: The mean TK gain was 16°, 14° and 28° in the whole cohort, normokyphosis group and hypokyphosis group, respectively. The mean DCL gain was, respectively, 9°, 7° and 20° and the mean CL gain 8°, 5° and 21°. There was a strong correlation between TK gain and CL gain (coefficient = 0.86) and between TK gain and DCL gain (coefficient = 0.74). The regression equation was defined as DCLgain = - 3 + 0.75 × TKgain (p < 0.0001) corresponding on average to 60% of the TK gain. CONCLUSION: 60% of the TK gain was transferred to DCL gain. Correlations reflect the geometrical equivalence between PTK and DCL. The use of sagittal global measurements shows that DCL is equivalent to PTK and can be expressed as a function of pelvic parameters (DCL = PT + LL-PI). DCL must be considered to optimize the postoperative sagittal alignment of the spine.

Efficacy of polyester bands placed under the transverse vertebral process for the correction of adolescent idiopathic scoliosis : A case series of 105 patients with a minimum of 24 months follow-up.

PURPOSE: To report an original technique for the surgical correction of adolescent idiopathic scoliosis (AIS) based on hybrid construct using polyester bands placed under the thoracic transverse processes. METHODS: We reviewed 105 patients operated between 2013 to 2017 for AIS with a minimum of 2 years follow-up. Clinical and radiological data, including 2D measurements of scoliosis parameters preoperatively, and at 3- and 24-months postoperatively were analyzed. Radiological analysis was performed by two independent observers using KEOPS (Smaio, Lyon-France, CE 2014) database. RESULTS: Mean age was 14.6 ± 2 years. Mean follow-up was 23.7 ± 1.2 months. Most curves were classified as Lenke-1 (78%). The average number of vertebra involved in the construct was 10.9 ± 1.3 (range 7-13). A mean of 12.8 implants were used per construct (mean implant density 0.59). The number of subtransverse bands placed averaged 3 (range 1-5 bands). The mean frontal Cobb angle decreased from 57.9 to 21.2 ° (p < 0.05) postoperatively. The average T4-T12 kyphosis increased from 20.2°to 32.4° (p < 0.05) postoperatively and no loss of correction was observed at 2 years follow-up. We encountered one case of transverse process fracture intraoperativley. No neurological complications were observed. In the postoperative period, 4 cases were diagnosed with distal junctional failure, three of which required an extension of the construct, while the fourth case was treated by bracing. CONCLUSIONS: The use of subtransverse band is an efficient and safe method for the surgical correction of AIS. This technique incorporates technical ease (minimal risk of neurological injury), provides good frontal correction and restores thoracic kyphosis. Results are maintained over a two-year period.

Predictive model of global tilt (GT) determined by individual thoracic kyphosis, lumbar lordosis and pelvic incidence in the human degenerative spine.

PURPOSE: Previous studies only investigated the simple linear relationships of global tilt (GT) with thoracic kyphosis (TK), lumbar lordosis (LL) and pelvic incidence (PI). This study aimed to establish multiple linear regressions of GT based on individual TK, LL and PI in patients with degenerative spines. METHODS: Four hundred sixty-nine adult patients aged older than 35 years with various degenerative spinal diseases were enrolled in this two-centre study between January 2017 and December 2020. Full-spine X-rays were performed for all the subjects in a standing position. The following regional and global parameters were measured in the sagittal plane: TK, LL, PI, pelvic tilt (PT), sagittal vertical axis (SVA) and GT. The correlations of the GT, PT and SVA with the TK, LL and PI were analysed, and then multiple linear regressions were constructed. RESULTS: GT was statistically correlated with TK, LL and PI. Additionally, TK, LL and PI were significant predictors for the GT, PT and SVA models. The relevant predictive formulae were as follows: GT = -9.60 + 1.09*PI + 0.89*LL + 0.42*TK (R2 = 0.935), PT = -4.49 + 0.81*PI + 0.56*LL + 0.24*TK (R2 = 0.792) and SVA = -25.68 + 2.98*LL + 2.37*PI + 1.67*TK (R2 = 0.416). CONCLUSION: The specific sagittal spinopelvic morphology, evaluated by GT parameters, should be determined by individual TK, LL and PI values in the degenerative spine. Surgeons can utilize such predictive models to better understand the degenerative evolution of sagittal alignment and recognize the relationships between regional parameters and global sagittal alignment to customize a precise correction strategy.

Patterns of coronal and sagittal deformities in adolescent idiopathic scoliosis.

BACKGROUND: Thoracic scoliosis has been shown to be associated with hypokyphosis in adolescent idiopathic scoliosis (AIS). However, the relationship of sagittal spino-pelvic parameters with different coronal curve patterns and their influence on patient-perceived quality of life is unknown. This study aims to determine the association between coronal and sagittal malalignment in patients with AIS and to determine their effects on SRS-22r scores. METHODS: A cross-sectional study was conducted on 1054 consecutive patients with AIS. The coronal Cobb angle, thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), PI-LL mismatch (PI-LL), pelvic tilt (PT), and sacral slope (SS) were measured on standing radiographs. The coronal Cobb angle (mild: 10-20°; moderate: > 20-40°; severe: > 40°) and PI (low: < 35°; average: 35-50°; high: > 50°) were divided into 3 sub-groups for comparison. Relationship between coronal curve magnitudes and sagittal parameters was studied as was their association with SRS-22r scores. RESULTS: Low PI had smaller SS (30.1 ± 8.3° vs 44.8 ± 7.7°; p < 0.001), PT (- 0.3 ± 8.1° vs 14.4 ± 7.5°; p < 0.001), and LL (42.0 ± 13.2° vs 55.1 ± 10.6°; p < 0.001), negative PI-LL mismatch (- 12.1 ± 13.1° vs 4.1 ± 10.5°; p < 0.001) as compared to large PI. There were no significant relationships with PI and TK (p = 0.905) or curve magnitude (p = 0.431). No differences in sagittal parameters were observed for mild, moderate or severe coronal Cobb angles. SRS-22r scores only correlated with coronal Cobb angle and larger Cobb angles were negatively correlated with the function, appearance and pain domains. CONCLUSIONS: The sagittal profile for AIS is associated with the pelvic parameters especially PI but not with the coronal curve pattern. All patients have a similar TK regardless of coronal curve type. However, it appears that the coronal deformity is a greater influence on quality of life outcomes especially those > 40°.

Retrospective analysis of the effect of breast surgery on body posture in patients with early-stage breast cancer after cancer treatment (VENUS study) (Breast cancer and body posture)

Background/aim: The aim of this study was to determine whether breast surgery changes body posture in patients with early-stage breast cancer. Materials and methods: Study variables include age, side and localization of the tumor in the breast, applied breast surgery, axillary interference, pathological tumor size, axillary lymph node metastasis, body mass index, bone density, adjuvant therapies, and histological type. Thoracic kyphosis angle due to the anatomically affected primary region to detect changes in body posture and Cobb's method were used to measure this. Results: There was a statistically significant difference in the mean Cobb's angle between the follow-up times of 57 patients (P < 0.001), with a cumulative increase in the Cobb's angle from baseline to the second year. As the age of the diagnosis progressed, the Cobb's angle increased significantly at 2 years when compared to baseline (r = 0,616, P < 0,001). In terms of baseline, the higher the BMI level in the 2nd year, the higher the Cobb's angle in the 2nd year as compared to the baseline (r = 0,529, P < 0,001). Conclusion: It was concluded that the increase in thoracic kyphosis in patients with breast cancer should be examined psychosocially. The study should be supported by a larger number of patients.

Lumbopelvic parameters can be used to predict thoracic kyphosis in adolescents.

PURPOSE: Distal thoracic kyphosis (DTK) equivalent to proximal lumbar lordosis (PLL) is the sum of pelvic tilt (PT) and the difference (Δ) between lumbar lordosis (LL) and pelvic incidence (PI): PLL = DTK = PT + Δ. With the assumption that proximal thoracic kyphosis (PTK) is similar to DTK, we propose the equation TK = 2(PT + LL - PI) to express the relationship between thoracic kyphosis (TK) and pelvic parameters. The objective of this work is to verify this relationship in a normal population. METHODS: Full spine radiographs of 100 adolescents and young adults (13 to 20 years old), free from vertebral pathology, were analyzed. Measurements included pelvic parameters, LL, PLL, DLL, TK, PTK, DTK and C7 global tilt. The measured global TK was compared with the theoretical TK calculated according to the formula TK = 2(PT + LL - PI). RESULTS: The difference between measured TK and calculated TK was + 2.3° and correlated with the C7 global tilt (r = 0.86). There was a significant linear regression between TK and PT + ∆ (p < 0.0001). Given radiographs' inter-rater reliability of 5° for angled measurements, the p value (0.047) between measured TK and calculated TK is statistically significant to support the hypothesis. CONCLUSION: This work validates the formula TK = 2(PT + LL - PI) which allows the calculation of global TK as a function of PT, LL and PI. This calculated TK can be used as a target for sagittal correction of adolescents with spine deformities. These slides can be retrieved under Electronic Supplementary Material.