Reliability of a New Digital Tool for Photographic Analysis in Quantifying Body Asymmetry in Scoliosis.

Background: Advancements in non-ionizing methods for quantifying spinal deformities are crucial for assessing and monitoring scoliosis. In this study, we analyzed the observer variability of a newly developed digital tool for quantifying body asymmetry from clinical photographs. Methods: Prospective observational multicenter study. Initially, a digital tool was developed using image analysis software, calculating quantitative measures of body asymmetry. This tool was integrated into an online platform that exports data to a database. The tool calculated 10 parameters, including angles (shoulder height, axilla height, waist height, right and left waistline angles, and their difference) and surfaces of the left and right hemitrunks (shoulders, waists, pelvises, and total). Subsequently, an online training course on the tool was conducted for twelve observers not involved in its development (six research coordinators and six spine surgeons). Finally, 15 standardized back photographs of adolescent idiopathic scoliosis patients were selected from a multicenter image bank, representing various clinical scenarios (different age, gender, curve type, BMI, and pre- and postoperative images). The 12 observers measured the photographs at two different times with a three-week interval. For the second round, the images were randomly mixed. Inter- and intra-observer variabilities of the measurements were analyzed using intraclass correlation coefficients (ICCs), and reliability was measured by the standard error of measurement (SEM). Group comparisons were made using Student's t-test. Results: The mean inter-observer ICC for the ten measurements was 0.981, the mean intra-observer ICC was 0.937, and SEM was 0.3-1.3°. The parameter with the strongest inter- and intra-observer validity was the difference in waistline angles 0.994 and 0.974, respectively, while the highest variability was found with the waist height angle 0.963 and 0.845, respectively. No test-retest differences (p > 0.05) were observed between researchers (0.948 ± 0.04) and surgeons (0.925 ± 0.05). Conclusion: We developed a new digital tool integrated into an online platform demonstrating excellent reliability and inter- and intra-observer variabilities for quantifying body asymmetry in scoliosis patients from a simple clinical photograph. The method could be used for assessing and monitoring scoliosis and body asymmetry without radiation.

Primary Pelvic Anteversion: Definition, Relevance And History After Surgery for Adult Spine Deformity.

STUDY DESIGN: Retrospective analysis of prospectively collected data. OBJECTIVE: To identify the best definition of primary anteverted pelvis in the setting of adult spine deformity (ASD), and to investigate whether this is a pathologic setting that requires surgical correction. SUMMARY OF BACKGROUND DATA: While pelvic retroversion has been thoroughly investigated, pelvic anteversion (AP) is a far lesser discussed topic. Four different AP definitions have been proposed, and AP has been described as a normal or pathologic entity by different authors. METHODS: All patients consulting for ASD at the five participating sites were included. Firstly, the four definitions of AP were compared with descriptive statistics (anatomic method - Pelvic Tilt <0°; Relative Pelvic Version method - RPV >5°; Roussouly method - Pelvic Incidence (PI)<50° and Sacral Slope (SS)>35°); low PT method - PT/PI <25th percentile). Secondly a subgroup analysis among operated AP patients with a two-year follow-up was performed. Complication rate, radiographic parameters and clinical scores (ODI, SF-36) were compared in a multivariate analysis between patients who did and did not maintain an AP at the 2-year follow-up. RESULTS: 1163 patients were available for the first analysis. The RPV method appeared to be the most appropriate to define AP in ASD patient. For the second analysis, data on 410 subjects were available, and most of them were young adults with idiopathic scoliosis that did not require pelvic fixation. AP patients who maintained an AP after ASD surgery presented comparable radiographic and clinical outcomes to the patients who presented a normo/retroverted pelvis after surgery. CONCLUSIONS: According to the results of the presented study, the RPV method is the most appropriate to define primary AP, which is not a pathologic condition and is most often observed in young adults with idiopathic scoliosis. Anteverted pelvis does not require direct surgical correction in this patient group.

Modern Concepts in Sagittal Curve Measurement: Comparison of Spline-based and Fixed Landmark Measurements in a Cohort of 1520 Healthy Subjects.

STUDY DESIGN: Retrospective multicenter study. OBJECTIVE: Our objective was to compare the spline-based measurement of sagittal spinal curvatures to fixed landmarks in a normative population. SUMMARY OF BACKGROUND DATA: Recent research has stressed the importance of considering sagittal curvature in their entirety using a spline reconstruction. To date, no data supports the superiority of this method in comparison to classic measurement methods. METHODS: Full spine biplanar radiographs of subjects over 20 years old who had normal radiographs were analyzed. Thoracic kyphosis (TK) and lumbar lordosis (LL) were measured following 2 modalities: either using predefined landmarks (TKT1T12, TKT5T12 and LLL1S1) or spline-based measurement (TKSpline and LLspline). RESULTS: 1520 subjects were included (mean 54yo). The mean difference between TKspline and TKT1T12 was 1.4° and between TKspline and TKT5T12 was 11.7° (P<0.001). LLslpine was significantly larger than LLL1S1 (55° vs 54°, P<0.001). LLslpine and LLL1S1 were correlated (R=0.950, P<0.001). Pelvic incidence had no influence on the difference between LLslpine and LLL1S1 (R=-0.034, P=0.184). Using LLL1S1 measurements, LL was underestimated in 17% of the cases. The comparison of outlier distribution according to age groups (P=0.175), gender (P=0.937) or PI groups (P=0.662) found no difference. There were significantly more outliers in Roussouly type 1 compared to other types (56%, P<0.001). CONCLUSION: Our results suggest that the use of TKT1T12 and LLL1S1 is acceptable to assess spinal sagittal curvatures. However, TKT5T12 is not accurate for thoracic curve and should be used with caution. LLL1S1 can be used to accurately assess the lumbar curve, except in Roussouly type 1.

Influence of age and severity of Lenke 5 or 6 idiopathic scoliosis on postoperative quality of life in adult patients.

INTRODUCTION: Thoracolumbar adolescent idiopathic scoliosis can continue to progress beyond skeletal maturity. Ideal timing of surgery remains undefined. Earlier intervention, with shorter instrumentation, incurs early partial loss of lumbar motion. Waiting for progression incurs a greater risk of extensive arthrodesis. The aim of the present study was to assess the quality-of-life impact of age and scoliosis severity at surgery. MATERIAL AND METHODS: Patients with Lenke 5 or 6 adolescent idiopathic scoliosis, aged 16-45years, were analyzed based on a prospective clinical registry. Oswestry Disability Index (ODI) and Scoliosis Research Society (SRS)-22 scores were collected preoperatively and at 6months, 1year and 2years. Coronal and sagittal alignments were measured on full-spine radiographs, and curve flexibility was assessed on bending radiographs. A mixed linear model was used to assess the impact of age, Cobb angle and flexibility on quality of life. RESULTS: Thirty-six patients were included. Mean ODI was 20.5% preoperatively and 13.8% at 2years (p=0.017). Mean SRS-22 was 3.2 preoperatively and 3.9 at 2years (p<0.001). Mean Cobb angle was 56.6° preoperatively and 23.2° at 2years (p<0.001), with mean preoperative reducibility of 68.1%. Age and ODI correlated preoperatively (r=0.6; p<0.001) and at 6months (r=0.5; p=0.002), as did age and SRS-22 (r=-0.6; p<0.001 and r=-0.6; p<0.001, respectively). Linear regression found a significant negative correlation between thoracolumbar Cobb angle and change in SRS-22 at 6months. DISCUSSION: In 16-45 year-olds with Lenke 5 or 6 idiopathic scoliosis, age influenced SRS-22 score. Younger patients had better quality of life both pre- and post-operatively. Curve magnitude influenced postoperative score. The present study suggests that early surgical correction in younger patients, where instrumentation can be shorter, does not impair quality of life. LEVEL OF EVIDENCE: IV; prospective registry study.

Variation of cervical sagittal alignment parameters according to age and pelvic incidence in degenerative spinal deformity patients.

INTRODUCTION: In asymptomatic subjects, variations of cervical sagittal alignment parameters according to age and spinopelvic organization have been reported. A large range of compensation phenomena has been observed in degenerative spinal deformity in order to maintain horizontal gaze, but it remains unclear how age and spinopelvic morphology could additionally influence cervical alignment. The aim of this observational retrospective study was to describe the distribution of cervical sagittal alignment parameters according to age and pelvic incidence in subjects with and without degenerative spinal deformity in order to precisely evaluate cervical compensation phenomena in adult spinal deformity (ASD). MATERIAL AND METHODS: Radiographs of 478 subjects (327 females and 151 males) were distributed into 235 asymptomatic and 243 deformed subjects. Occipito-cervical parameters were McGregor-C1, McGregor-C2, C1-C2 and occipito-C2 angles. The cervicothoracic inflection point (CTIP) was determined. Caudal cervical sagittal alignment parameters were: C2-C7 lordosis, C2-apex (superior arch), apex-CTIP (inferior arch), occipito-C3 and occipito-C4 angles, C7-slope and T1-slope. The distribution of parameters was analyzed using a Bayesian inference (significant when Pr > 0.975 or Pr < 0.025). Comparisons between asymptomatic and deformed subjects were done after matching on age (40-60 years; > 60 years) and on PI (< 45°; 45-60°; > 60°). RESULTS: Among occipito-cervical parameters, there was no significant change in McGregor-C1 angle. However, McGregor-C2 angle was significantly higher in the ASD group (Pr = 0.0029), with influence of age (Pr = 0.023), but PI influence. C1-C2 lordosis was significantly higher in the ASD group compared to the asymptomatic group (Pr < 0.0007), without influence of age or PI noticed. C2-C7 lordosis was also higher in the ASD group (Pr < 0.025) with a role of age and PI (Pr < 0.025). Cervical lordosis in the superior arch was significantly higher in the ASD group (Pr > 0.999), without influence of age or PI. In the inferior arch, the lordosis angle was not modified according to the group, but there was an influence of age (Pr < 0.0007). C7-slope and T1-slope were higher according the age group (Pr < 0.0012), without influence of the group or PI. CONCLUSION: This observational study highlights cervical sagittal alignment adaptations in degenerative spinal deformity, matched on age and pelvic incidence. The inferior cervical spine seemed to be modified with a higher lordosis, increasing with age responding to the age-related thoracic kyphosis increase. In addition to that, the superior cervical spine hyperextends more in adult degenerative deformity to maintain horizontal gaze. LEVEL OF EVIDENCE: III.

Anterolateral versus posterior minimally invasive lumbar interbody fusion surgery for spondylolisthesis: comparison of outcomes from a global, multicenter study at 12-months follow-up.

BACKGROUND CONTEXT: Several minimally invasive lumbar interbody fusion techniques may be used as a treatment for spondylolisthesis to alleviate back and leg pain, improve function and provide stability to the spine. Surgeons may choose an anterolateral or posterior approach for the surgery however, there remains a lack of real-world evidence from comparative, prospective studies on effectiveness and safety with relatively large, geographically diverse samples and involving multiple surgical approaches. PURPOSE: To test the hypothesis that anterolateral and posterior minimally invasive approaches are equally effective in treating patients with spondylolisthesis affecting one or two segments at 3-months follow-up and to report and compare patient reported outcomes and safety profiles between patients at 12-months post-surgery. DESIGN: Prospective, multicenter, international, observational cohort study. PATIENT SAMPLE: Patients with degenerative or isthmic spondylolisthesis who underwent 1- or 2-level minimally invasive lumbar interbody fusion. OUTCOME MEASURES: Patient reported outcomes assessing disability (ODI), back pain (VAS), leg pain (VAS) and quality of life (EuroQol 5D-3L) at 4-weeks, 3-months and 12-months follow-up; adverse events up to 12-months; and fusion status at 12-months post-surgery using X-ray and/or CT-scan. The primary study outcome is improvement in ODI score at 3-months. METHODS: Eligible patients from 26 sites across Europe, Latin America and Asia were consecutively enrolled. Surgeons with experience in minimally invasive lumbar interbody fusion procedures used, according to clinical judgement, either an anterolateral (ie, ALIF, DLIF, OLIF) or posterior (MIDLF, PLIF, TLIF) approach. Mean improvement in disability (ODI) was compared between groups using ANCOVA with baseline ODI score used as a covariate. Paired t-tests were used to examine change from baseline in PRO for both surgical approaches at each timepoint after surgery. A secondary ANCOVA using a propensity score as a covariate was used to test the robustness of conclusions drawn from the between group comparison. RESULTS: Participants receiving an anterolateral approach (n=114) compared to those receiving a posterior approach (n=112) were younger (56.9 vs 62.0 years, p <.001), more likely to be employed (49.1% vs 25.0%, p<.001), have isthmic spondylolisthesis (38.6% vs 16.1%, p<.001) and less likely to only have central or lateral recess stenosis (44.9% vs 68.4%, p=.004). There were no statistically significant differences between the groups for gender, BMI, tobacco use, duration of conservative care, grade of spondylolisthesis, or the presence of stenosis. At 3-months follow-up there was no difference in the amount of improvement in ODI between the anterolateral and posterior groups (23.2 ± 21.3 vs 25.8 ± 19.5, p=.521). There were no clinically meaningful differences between the groups on mean improvement for back- and leg-pain, disability, or quality of life until the 12-months follow-up. Fusion rates of those assessed (n=158; 70% of the sample), were equivalent between groups (anterolateral, 72/88 [81.8%] fused vs posterior, 61/70 [87.1%] fused; p=.390). CONCLUSIONS: Patients with degenerative lumbar disease and spondylolisthesis who underwent minimally invasive lumbar interbody fusion presented statistically significant and clinically meaningful improvements from baseline up to 12-months follow-up. There were no clinically relevant differences between patients operated on using an anterolateral or posterior approach.

Lumbar scoliosis and stenosis: What outcomes for which treatment? Analysis of three surgical techniques in 154 patients with minimum two-year follow-up.

STUDY DESIGN: Prospective multicentric study. OBJECTIVE: This study goal was to analyze the clinical and radiographic outcomes of lumbar stenosis and scoliosis (LSS) patients, treated with lumbar decompression (LD), short fusion and decompression (SF) or long fusion with deformity correction (LF). HYPOTHESIS: Procedures without correction lead to poorer long-term outcomes. METHODS: Consecutive patients with two-year minimum follow-up, older than 50, with lumbar scoliosis (Cobb angle>15°), and symptomatic lumbar stenosis were included. Age, gender, Lumbar and Radicular Visual Analog Scale, ODI, SF12 and SRS30 were collected. Main and adjacent curves Cobb angles, C7 coronal tilt (C7CT), spinopelvic parameters, and spino-sacral angle (SSA) were measured preoperatively, at one and two years. Patients were sorted into surgery type groups. RESULTS: In total, 154 patients were included, with respectively 18, 58 and 78 patients in LD, SF and LF groups. Mean age was 69, 85% were women. Clinical scores improved in each group at one year, but only LF group exhibited persistent improvement at 2years. A significant fractional Cobb angle increase was noted in the SF group at 2years (from 12±11° to 18±14°). C7CT significantly increased in the LD group at 2years (from 2.5±1.3° to 5.1±3.5°). LF group presented the highest complication rate (45%, 19% for SF and 0% for LD). The overall revision rate was 14% in SF group and 30% in LF group. CONCLUSION: LSS is a complex pathology requiring custom-made surgical treatment. LD, SF and LF allow satisfactory clinical outcome, with a better and more sustained clinical improvement for LF despite higher complication and revision rates. LEVEL OF EVIDENCE: IV.

Spinal Sagittal Alignment Changes During Childhood: Results of a National Cohort Analysis of 1,059 Healthy Children.

BACKGROUND: In the past decades, it has been recognized that sagittal alignment of the spine is crucial. Although the evolution of spinal alignment with growth has previously been described, there are no data for key parameters such as the exact shapes (extent and magnitude) of spinal curvatures. The goals of this study were therefore to determine normative values of spinopelvic sagittal parameters and to explore their variation during growth, based on the analysis of a large national cohort of healthy children. METHODS: The radiographic data of 1,059 healthy children were analyzed in a retrospective, multicenter study. Full spine radiographs were used to measure several sagittal parameters, such as pelvic parameters, T1-T12 thoracic kyphosis (TK), and L1-S1 lumbar lordosis (LL). TK was divided into proximal, middle, and distal parts, and LL was divided into proximal and distal parts. Patients were stratified into 5 groups according to skeletal maturity (based on age, Risser stage, and triradiate cartilage status). RESULTS: During growth, pelvic incidence increased from 40° to 46° and pelvic tilt increased from 4° to 9° (p < 0.05), whereas sacral slope remained constant. The peak of change in pelvic parameters occurred at the beginning of pubertal growth in Group 2 (the first part of the pubertal growth spurt). TK slightly increased among groups from 39° to 41° (p = 0.005), with the peak of change occurring in Group 4 (pubertal growth deceleration). LL increased from 51° to 56° (p < 0.001), with the peak of change occurring in Group 3 (the second part of the pubertal growth spurt). Segmental analysis revealed that most of the TK and LL changes occurred in the distal TK and proximal LL, with the other parts remaining constant. CONCLUSIONS: This is one of the largest studies showing changes in sagittal alignment with growth in normal children and adolescents. We found that changes in spinal shape were cascading phenomena. At the beginning of the growth peak, pelvic incidence increased. This change in pelvic morphology led to an increase in LL, involving its proximal part. Finally, TK increased, in its distal part, at the end of pubertal growth. LEVEL OF EVIDENCE: Prognostic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Thoracolumbar Sagittal Shape Varies With Pelvic Morphology and Aging.

STUDY DESIGN: Retrospective study of a multicenter prospective database. OBJECTIVE: The objective of this study was to determine the organization and correlations between different spinal segments according to pelvic incidence (PI) and age. SUMMARY OF BACKGROUND DATA: When planning surgery for the correction of adult spinal deformities, considering lumbar lordosis (LL) as a uniform segment is an approximation that can lead to planning errors. MATERIALS AND METHODS: Radiographs of 1540 subjects were analyzed and divided into three PI groups: low <45, intermediate 45 to 60, high >60, and stratified by age (<45, 45-70, and >70 yr). The different segments of L1-L4 proximal lumbar lordosis (PLL), L4-S1 distal lumbar lordosis (DLL), and T10-L1 thoracolumbar junction (TLJ) were analyzed. RESULTS: The mean age was 53.5 years (SD=17, minimum=20, maximum=93). There was a significant correlation between thoracic kyphosis T5-T12 and TLJ segment T10-L1 ( r =0.581, P <0.001). Only the L1-L4 PLL segment correlated with PI ( r =0.47, P <0.001). The T10-L1 TLJ segment was constant regardless of age or PI groups considered (mean=-8, SD=9). PLL did not vary with aging but differed according to PI. The DLL showed significant differences between age and PI groups but without a significant correlation between PI and DLL. CONCLUSIONS: Pelvic morphology is known to determine the curvatures of the spine, however, the distribution of LL is not homogeneous. Our study provided a normative value reference and showed that T10-L1 is constant regardless of age or PI. LEVEL OF EVIDENCE: III.

Proximal and distal mechanical repercussions of instrumentation by double rods and interbody grafts in adult scoliosis.

INTRODUCTION: Correction of adult scoliosis by instrumentation with double rods and interbody grafts aims to reduce the risk of pseudarthrosis with rod fracture. An increase in instrumentation rigidity can lead to an increase in stresses at the proximal and distal ends of the construct. The aim of this study was to analyze the incidence and clinical repercussions of proximal junctional kyphosis (PJK), proximal junctional failure (PJF) and iliac screw loosening. MATERIEL AND METHODS: An analysis of patients operated on for adult scoliosis with instrumentation to the pelvis using 4 rods and interbody cages was carried out from a prospective register. The Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Scoliosis Research Society 22 (SRS-22) clinical scores and radiological parameters were collected preoperatively, postoperatively at 3 months, 1 year and 2 years. The appearance of PJK, PJF or distal screw loosening was sought; the clinical impact and the risk factors were analyzed by Bayesian inference. RESULTS: Fifty-one patients with a mean age of 64.5 years were included. The clinical scores improved significantly (Pr>0.95) at 2 years: VAS back 6.9 versus 2.6, VAS leg 4.9 versus 2.5, ODI 48.2 versus 25.4, SRS-22 2.4 versus 3.5. The radiological parameters were corrected (Pr>0.95): Cobb angle 63.9° versus 22.8°, spinosacral angle (SSA) 112.4° versus 118.8°, T1-pelvic angle (TPA) 24, 8° versus 20.8°, lumbar lordosis 43.8° versus 51.0°, thoracic kyphosis 45.2° versus 53.6°. Thirteen patients (25.5%) presented with PJK and 11 (21.6%) with PJF. Seven patients (13.7%) presented with iliac screw loosening. None of these complications was associated with a significant deterioration in clinical scores. Cranial migration of the lumbar apex increased the risk of distal screw loosening: Odds-Ratio 10.31 (Pr>0.999). Two patients were re-operated on for PJF and one patient for iliac screw loosening (5.9%). No rod fracture with pseudarthrosis was found. CONCLUSION: Instrumentation with double rods and interbody grafts was associated with a rate of 47.1% of mechanical repercussions at the extremity of the construct. However, these complications were not associated with a significant deterioration in clinical scores. LEVEL OF EVIDENCE: III.

Surgical management of isthmic spondylolisthesis: A comparative study of postoperative outcomes between ALIF and TLIF.

INTRODUCTION: Circumferential fusion by the anterior (ALIF) or transforaminal (TLIF) approach combined with posterior instrumentation is currently used for the surgical treatment of low-grade isthmic spondylolisthesis. But few studies have compared the clinical and radiological outcomes of various interbody fusion techniques. The objective of this study was to compare the clinical and radiological results at 2 years postoperative of two fusion techniques-TLIF versus ALIF plus posterior instrumentation-for low-grade isthmic spondylolisthesis in adults. MATERIALS AND METHODS: This was an observational multicenter study done at nine French healthcare facilities specialized in spine surgery. The inclusion criteria were minimum age of 18 years, grade 1-3 isthmic spondylolisthesis, ALIF+posterior fixation (ALIF+PS) or TLIF, minimum follow-up of 2 years. Clinical and radiological evaluations were done preoperatively and at 2 years of follow-up. A lumbar CT scan was done at 1 year postoperative to evaluate fusion. RESULTS: The cohort consisted of 89 patients (50 women, 39 men) with a mean age of 47.7±12.3 (18-79) years. The patients in the ALIF groups (n=71) had a significantly longer hospital stay than those in the TLIF group (n=18): 5.7 days versus 4.6 days (p=.04). However, their medical leave from work was significantly shorter: 31.0 weeks versus 40.7 (p=.003). Lumbar pain VAS diminished faster in the ALIF groups, with a significantly larger drop than the TLIF group in the first 3 months postoperative. Only the increase in lumbar disc lordosis was larger in the ALIF group: 11.7°±12.0° versus 6.0°±11.7° (p=.036). There was a significant correlation between the increase in global lordosis and reduction in lumbar VAS at 2 years postoperative (ρ=-0.3295; p=.021). CONCLUSION: ALIF+PS provides a faster relief of postoperative low back pain than TLIF but there are no significant clinical differences between techniques at 2 years of follow-up. Despite better restoration of disc lordosis in the ALIF+PS group, there was no difference in the restoration of global lordosis. LEVEL OF EVIDENCE: III; multicenter comparative study.

Artificial intelligence and treatment algorithms in spine surgery.

Artificial intelligence (AI) is a set of theories and techniques in which machines are used to simulate human intelligence with complex computer programs. The various machine learning (ML) methods are a subtype of AI. They originate from computer science and use algorithms established from analyzing a database to accomplish certain tasks. Among these methods are decision trees or random forests, support vector machines along with artificial neural networks. Convolutive neural networks were inspired from the visual cortex; they process combinations of information used in image or voice recognition. Deep learning (DL) groups together a set of ML methods and is useful for modeling complex relationships with a high degree of abstraction by using multiple layers of artificial neurons. ML techniques have a growing role in spine surgery. The main applications are the segmentation of intraoperative images for surgical navigation or robotics used for pedicle screw placement, the interpretation of images of intervertebral discs or full spine radiographs, which can be automated using ML algorithms. ML techniques can also be used as aids for surgical decision-making in complex fields, such as preoperative evaluation of adult spinal deformity. ML algorithms "learn" from large clinical databases. They make it possible to establish the intraoperative risk level and make a prognosis on how the postoperative functional scores will change over time as a function of the patient profile. These applications open a new path relative to standard statistical analyses. They make it possible to explore more complex relationships with multiple indirect interactions. In the future, AI algorithms could have a greater role in clinical research, evaluating clinical and surgical practices, and conducting health economics analyses.

Psychopathological profile and sagittal alignment in low-back pain.

INTRODUCTION: Low-back pain requires comprehensive care using a biopsychosocial model. The psychologic dimension plays an important role, but the link between sagittal alignment and a given psychopathological profile is little studied. The aim of this study was to analyze the psychopathological profiles and sagittal parameters of a population with low-back pain and to assess the link. MATERIAL AND METHODS: 205 patients, with a mean age of 49.6 years (range, 18-70 years), presenting chronic common low-back pain without radicular involvement, were included prospectively. Mood scores comprised: the self-administered "Hospital Anxiety and Depression Scale" (HAD), Hamilton Anxiety Scale (HAM-A), Hamilton Depression Scale (HAM-D) and Young Mania Rating Scale (YMRS). Radiological parameters, measured on lateral full-spine radiographs, included: L1-S1 lordosis, T1-T12 kyphosis, pelvic incidence, pelvic tilt, sacral slope, sagittal vertical axis (SVA), T1 slope, and Roussouly type. RESULTS: Mean HAM-A score was 16.1; 54% of patients had scores ≥14, indicating anxiety disorder. Mean HAM-D score was 10.8; 55% of patients had scores ≥10, indicating depressive disorder. Mean YMRS score was 2.6; only 1 patient had a score ≥20, indicating manic disorder. The 112 patients with HAM-A score >14 showed mean 51.6° L1-S1 lordosis (p=0.356), 48.3° T1-T12 kyphosis (p=0.590), -4.3mm C7 SVA (p=0.900), and 29.3° T1 slope (p=0.451). In case of HAM-A <14, there were no significant differences. The 113 patients with HAM-D score >10 showed significant differences in T1-T12 kyphosis (mean 49.0°; p<0.05) and T1 slope (30.2°; p<0.05); mean L1-S1 lordosis was 50.5° (p=0.861) and C7 SVA 1.6mm (p=0.462). In case of HAM-D <10, T1-T12 kyphosis was 45.5° (p<0.05) and T1 slope 26.2° (p<0.05); mean lordosis was 50.9° (p=0.861) and mean C7 SVA -7.1mm (p=0.259). Multivariate analysis found no significant link between Roussouly type and psychiatric scores: HAD (p=0.715), HAM-A (p=0.652), and HAM-D (p=0.902). CONCLUSION: More than 50% of patients with common low-back pain presented a mood disorder. Depressive disorder was associated with greater T1-T12 kyphosis and T1 slope. There was no relationship between psychiatric scores and overall sagittal alignment. LEVEL OF EVIDENCE: II.

Fusion and clinical outcomes of lumbar interbody fusion for low-grade isthmic spondylolisthesis.

INTRODUCTION: Low-grade isthmic spondylolisthesis (ISPL) is generally treated by circumferential fusion with interbody graft, although there is no consensus on technique. HYPOTHESIS: The various interbody fusion strategies provide satisfactory fusion rates and clinical results. METHODS: A multicenter retrospective study analyzed lumbar interbody fusion for low-grade ISPL performed between March 2016 and March 2019. Techniques comprised: circumferential fusion on a posterior or a transforaminal approach (PLIF, TLIF: n=57), combined anterior (ALIF)+posterolateral fusion (ALIF+PLF: n=60), and ALIF+percutaneous posterior fixation (ALIF+PPF: n=55). Function was assessed on a lumbar and a radicular visual analog scale (AVS-L, VAS-R), Oswestry Disability Index (ODI) and Short Form 12 (SF12). RESULTS: Among the 129 patients, 85.3% showed fusion (Lenke 1 or 2), with no significant differences between the ALIF-PLF or ALIF-PPF groups and the PLIF or TLIF groups (p=0.3). Likewise, there was no difference in fusion rates between the ALIF-PPF and ALIF-PLF subgroups (p=0.28). VAS-L (p<0.001) and VAS-R (p<0.0001), ODI (p<0.001) and SF12 physical (PCS) (p<0.01) and mental component sores (MCS) (p<0.001) all showed significant improvement at 12months. Combined approaches provided greater clinical efficacy than TLIF or PLIF for lumbar (p<0.0001) and radicular pain (p<0.05), ODI (p<0.0001) and SF12 PCS (p<0.01). At 12months, there was no clinical difference between the ALIF-PPF and ALIF-PLF subgroups. However, patents with interbody non-union (Lenke 3 or 4) had lower SF12 PCS scores (p<0.004) and VAS-L ratings (p<0.001) than Lenke 1-2 patients. CONCLUSION: Low-grade ISPL treated by circumferential arthrodesis and interbody graft showed 85.3% consolidation at 2years, with equivalent outcomes between anterior and posterior techniques. Successful fusion was associated with better clinical results. LEVEL OF EVIDENCE: IV.

How was spinal surgery activity maintained during the COVID-19 pandemic? Results of a French multicenter observational study.

INTRODUCTION: The French Society of Spinal Surgery (SFCR) offered guidelines during the COVID pandemic. The objective of this work was to report the organization and activity in spinal surgery during the first month of confinement across 6 centers in France. The secondary objective was to monitor the adequacy of our practices within the SFCR guidelines. MATERIAL AND METHODS: This prospective multicenter observational study reported spinal surgery activity in each institution from March 16 to April 16, 2020, as well as the organizational changes applied. Surgical activity was compared to that of the same period in 2019 in each center and evaluated according to the SFCR guidelines, in order to control the adequacy of our practices during a pandemic period. RESULTS: During the peak of the epidemic, 246 patients including 6 COVID-positive patients were treated surgically. The most significant drops in activity were found in Strasbourg (-81.5%) and Paris (-65%), regions in which the health situation was the most critical, but also in Bordeaux (-75%) despite less viral circulation. Operating rooms functioned at 20 to 50% of their normal capacity. There was a significant reduction in procedures for degenerative spine conditions or deformities, in line with the SFCR guidelines. CONCLUSION: Maintaining spinal surgery is possible and desirable, even in times of health crisis. The indications must be considered according to the emergency criteria developed by learned societies and adapted to health developments and to the technical possibilities of treatment, by center. LEVEL OF PROOF: IV.

Do Age-Related Variations Of Sagittal Alignment Rely On SpinoPelvic Organization? An Observational Study Of 1540 Subjects.

STUDY DESIGN: Descriptive radiographic analysis of a prospective multi-center database. OBJECTIVE: This study aims to provide normative values of spinopelvic parameters and their correlations according to age and pelvic incidence (PI) of subjects without spinal deformity. METHODS: After Institutional Review Board (IRB) approval, 1540 full spine radiographs were analyzed. Subjects were divided into 3 groups of PI: low PI < 45°, intermediate PI 45-60°, high PI > 60°, and then stratified by age (20-34, 35-49, 50-64, > 65 Y.O). Pelvic and spinal parameters were measured. Statistical analysis between parameters was performed using Bayesian inference and correlation. RESULTS: Mean age was 53.5 years (845 females, 695 males, range 20-93 years).In low PI group, lumbar lordosis (LL) decrease was mainly observed in the 2 younger age groups.In medium and high PI groups, loss of lordosis was linear during aging and occurred mainly on the distal arch of lordosis. Moderate PI group had a stable lordosis apex and thoracolumbar inflection point. High PI group had a stable thoracolumbar inflection point and a more distal lordosis apex in elderly subjects.For all subjects, kyphosis and pelvic tilt (PT) increased with age.There was a constant chain of correlation between PI and age groups. Proximal lumbar lordosis (PLL) was correlated with kyphosis and sagittal vertical axis (SVA C7), while the distal lumbar lordosis (DLL) was correlated with PI and PT. CONCLUSION: This study provides a detailed repository of sagittal spinopelvic parameters normative values with detailed analysis of segmental kyphosis and lordosis distribution according to gender, age, and PI.

The influence of total disc arthroplasty with Mobidisc prosthesis on lumbar spine and pelvic parameters: a prospective in vivo biomechanical study with a minimum 3 year of follow-up.

BACKGROUND: This study examined the impact of Mobidisc implant on spinopelvic parameters, with particular focus on the preservation of the lumbar lordosis (LL) and on the segmental lordosis (SL) of the treated and adjacent segments. METHODS: A prospective study was conducted on 63 consecutive patients with symptomatic degenerative disc disease who underwent Mobidisc implantation at the Clinic for Spinal Diseases in Strasbourg, France. Based on the profile images of the whole, the following static spinopelvic parameters were measured and analysed: lumbar lordosis L1-S1 (LL), SL for L3-L4, L4-L5 and L5-S1, sacral slope (SS), pelvic tilt (PT) and pelvic incidence. In the lumbar spine images, the anterior (ADH) and posterior disc height (PDH) were measured prior to surgery and at the different follow-up appointments. The preoperative and postoperative values were compared and statistically analysed at different time intervals. RESULTS: Sixty-three patients were included in the study. The average age of the patients was 41.4 years (range 27-59 years). The mean follow-up was 44 months (range 36-71 months). Overall, total disc replacement (TDR) led to an increase in LL which increased TED over time. The preoperative LL measured 48.9° ± 10.1° and 53.4° ± 9.9° at 3 years follow-up (p < 0.0001). In the cohort of patients who underwent TDR at L4-5, the LL increased from 51.6° ± 10° to 56.2° ± 9.2° at the last FU (p = 0.006). All other spinopelvic parameters remained stable between the preoperative values and the last follow-up. In the patients who underwent L5-S1 TDR, a significant increase in LL was also observed between preoperative data and at the last FU (from 47.8° ± 10.1° to 53.3° ± 10.1°, p < 0.0001). Following L5-S1 TDR, the SS increased from 32.9° ± 8.3° to 35.6° ± 7.4° (p = 0.05) and the PT decreased from 15.4° ± 6.2° to 11.6° ± 5.7° between preoperative values and the last follow-up. Considering the entire cohort, the SL L5-S1 increased significantly from 5.9° ± 4.2° preoperatively to 8.1° ± 4.4° (p < 0.01) at the last FU, while at the L4-L5 level, the SL remained stable from 9.9 ± 4.5° to 10.7° ± 3.8° (p = 0.3). After L4-5 TDR, an increase in ADH and PDH at the treated level was observed, while these parameters progressively decreased in the adjacent segment. In patients who underwent L5-S1 TDR, a significant increase in L5-S1 ADH and PDH was observed from 18.8 ± 9.1 to 28.4 ± 11.1 and from 9.5 ± 3.8 to 17.6 ± 9.5 pixels, respectively. ADH and PDH at the proximal adjacent levels L3-4 and L4-5 were reduced. We did not observe any case of implant failure or damage to the bone/implant interface. CONCLUSION: TDR with Mobidisc allows for an improvement of LL and SL at the treated level. An increase in both anterior and posterior disc height was observed at the treated level. While disc height decreased at the adjacent level, further studies are required to investigate whether these changes are clinically relevant.

Can Lumbopelvic Parameters Be Used to Predict Thoracic Kyphosis at all Ages? A National Cross-Sectional Study.

STUDY DESIGN: National cross-sectional study. BACKGROUND: Thoracic kyphosis (TK) is related to sagittal parameters as pelvic tilt (PT), lumbar lordosis (LL) and pelvic incidence (PI). The equation TK =2 (PT+LL-PI) was validated for adolescents.Objective: to investigate if this equation correctly predicts TK regardless of age. METHODS: Sagittal alignment parameters were assessed on full spine radiographs of 2599 individuals without spine pathology (1488 females, 1111 males). Calculated TK (CTK) = 2 (PT+LL-PI) and measured TK (MTK) were compared by calculating the gap and using a linear regression between both parameters. Subgroup analyses were performed for gender, age, TK groups (≤20°, 21°-40°, 41°-60°, >60°), and PI groups (<45°, 45°-60°, >60°). RESULTS: Average values in the total population were: MTK 45.0°, CTK 36.9°. Average TK gap was 8.1°, 5.2° in females (intercept 11.7, slope .61) and 11.9° in males (intercept 7.1, slope .58). The mean gap was 3.6° for 15-34 years, 5.7° under 15 years and it increased progressively after 35 years with a maximum of 19.9° over 80 years. The gap also increased with the amount of MTK: -3.5° for TK<20° up to 17.3° for TK >60°. Differences in gaps were minor between PI groups. The intercept was smallest and slopes >.6 for PI <45° and TK ≤20°. CONCLUSION: The formula TK=2 (PT+LL-PI) yielded moderate accuracy for adolescents and young adults, but did not fit for over 35 years and under 15. The amount and variance in TK increased in elderly subjects, which made the formula less accurate.

Comparison of Spinopelvic Configuration and Roussouly Alignment Types Between Pediatric and Adult Populations.

STUDY DESIGN: Retrospective cross-sectional study. OBJECTIVE: The aim was to describe spinopelvic alignment types by pelvic incidence (PI) and age to compare the Roussouly classification between pediatric and adult populations. SUMMARY OF BACKGROUND DATA: The Roussouly classification was validated for adults. Alignment types may vary during growth. MATERIALS AND METHODS: Radiographs of 1706 non pathologic individuals (5-49 yr) were analyzed. Individuals ≤19 years were stratified by chronological age and skeletal maturity (triradiate cartilage, Risser), and compared with adults. Global and spinopelvic alignment parameters were assessed. Roussouly Types 1, 2, 3, 3A (anteverted pelvis), and 4 were determined. The distribution of parameters was analyzed by Bayesian inference. The relationship between PI and age by Roussouly type was modeled by linear regression. RESULTS: The Sagittal Vertical Axis C7 decreased during growth and was significantly smaller in adults (20-34 yr) (Pr>0.99). Thoracic kyphosis and lumbar lordosis increased during growth and were larger in adults (Pr<0.025). Lordosis increased mainly in the cranial arch (Pr<0.025). PI and pelvic tilt increased during growth and were larger in adults (Pr<0.025). In children and adolescents, PI<45° represented the largest proportion, significantly larger compared with adults (Pr>0.99). Proportions of Roussouly Types 1 and 2 were similar throughout ages. Types 3 and 4 were rarer during the prepubertal period (Pr<0.025). The proportion of Type 3A was significantly higher in children and adolescents (Pr>0.99). Linear regression showed that Type 4 had the largest PI increase with age, with significantly higher curve slope compared with other types (Pr>0.9999). Types 3, 3A and 2 had similar slopes and lowest PI increase with age. CONCLUSION: Global and spinopelvic alignment changed during childhood and adolescence, leading to different kyphosis and lordosis distribution compared with adults. Growth-related PI increase influenced Roussouly types with typical predominance of Type 3A in the pediatric population and larger PI increase in Type 4. LEVEL OF EVIDENCE: Level III.