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Introduction: Degenerative spondylolisthesis causes translational and angular malalignment, resulting in a loss of segmental lordosis. This leads to compensatory adjustments in adjacent levels to maintain balance. Lateral lumbar interbody fusion (LLIF) and transforaminal lumbar interbody fusion (TLIF) are common techniques at L4-5. This study compares compensatory changes at adjacent L3-4 and L5-S1 levels six months post LLIF versus TLIF for grade 1 degenerative spondylolisthesis at L4-5., Methods: A retrospective study included patients undergoing L4-5 LLIF or TLIF with posterior pedicle screw instrumentation (no posterior osteotomy) for grade 1 spondylolisthesis. Pre-op and 6-month post-op radiographs measured segmental lordosis (L3-L4, L4-L5, L5-S1), lumbar lordosis (LL), and pelvic incidence (PI), along with PI-LL mismatch. Multiple regressions were used for hypothesis testing., Results: 113 patients (61 LLIF, 52 TLIF) were studied. TLIF showed less change in L4-5 lordosis (mean = 1.04°, SD = 4.34) compared to LLIF (mean = 4.99°, SD = 5.53) (p = 0.003). L4-5 angle changes didn't correlate with L3-4 changes, and no disparity between LLIF and TLIF was found (all p > 0.16). In LLIF, greater L4-5 lordosis change predicted reduced compensatory L5-S1 lordosis (p = 0.04), while no significant relationship was observed in TLIF patients (p = 0.12)., Conclusion: LLIF at L4-5 increases lordosis at the operated level, with compensatory decrease at L5-S1 but not L3-4. This reciprocal loss at adjacent L5-S1 may explain inconsistent improvement in lumbar lordosis (PI-LL) post L4-5 fusion., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Severe sagittal plane deformity with loss of L4-S1 lordosis is disabling and can be improved through various surgical techniques. However, data are limited on the differing ability of anterior lumbar interbody fusion (ALIF), pedicle subtraction osteotomy (PSO), and transforaminal lumbar interbody fusion (TLIF) to achieve alignment goals in severely malaligned patients., Methods: Severe adult spinal deformity patients with preoperative PI-LL >20°, L4-S1 lordosis <30°, and full body radiographs and PROMs at baseline and 6-week postoperative visit were included. Patients were grouped into ALIF (1-2 level ALIF at L4-S1), PSO (L4/L5 PSO), and TLIF (1-2 level TLIF at L4-S1). Comparative analyses were performed on demographics, radiographic spinopelvic parameters, complications, and PROMs., Results: Among the 96 included patients, 40 underwent ALIF, 27 underwent PSO, and 29 underwent TLIF. At baseline, cohorts had comparable age, sex, race, Edmonton frailty scores, and radiographic spinopelvic parameters (P > 0.05). However, PSO was performed more often in revision cases (P < 0.001). Following surgery, L4-S1 lordosis correction (P = 0.001) was comparable among ALIF and PSO patients and caudal lordotic apex migration (P = 0.044) was highest among ALIF patients. PSO patients had higher intraoperative estimated blood loss (P < 0.001) and motor deficits (P = 0.049), and in-hospital ICU admission (P = 0.022) and blood products given (P = 0.004), but were otherwise comparable in terms of length of stay, blood transfusion given, and postoperative admission to rehab. Likewise, 90-day postoperative complication profiles and 6-week PROMs were comparable as well., Conclusions: ALIF can restore L4-S1 sagittal alignment as powerfully as PSO, with fewer intraoperative and in-hospital complications. When feasible, ALIF is a suitable alternative to PSO and likely superior to TLIF for correcting L4-S1 lordosis among patients with severe sagittal malalignment., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: To identify variables that may contribute to the development of proximal junctional failure (PJF) in patients with long lumbo-sacral and thoraco-lumbo-pelvic constructs undergoing anterior column realignment (ACR) with anterior longitudinal ligament release (ALLR)., Methods: Data of patients with adult spinal deformity who underwent ACR with ALLR at L3-4 were collected retrospectively from medical records and a prospectively maintained spine research database between 2016 and 2022., Results: Eleven (41%) developed PJF at a mean of 24 ± 21 months from the index surgery. The cohort was then divided into 2 groups for analysis, 13 subjects in the high pelvic incidence (PI) group (defined as PI ≥ 55°) and 14 subjects in the low PI group (defined as PI < 55°). Visual Analog Scale for back pain and Oswestry Disability Index decreased from 9.5 to 2.1 and 61 to 10 in the high PI group, and from 8.9 to 2.4 and 60.9 to 10.3 in the low PI group, respectively. PI (P = 0.004), sacral slope (P = 0.005), and postoperative PI-lumbar lordosis mismatch (P = 0.02) were found to be significant predictors of PJF. The receiver operator curve revealed a cutoff PI value ≤ 53° (95% confidence interval: 52°-64°), below which the risk of PJF becomes significantly higher in patients undergoing ACR with ALLR at L3-4., Conclusions: PI may be a predictor of PJF and highly correlates with ACR-ALLR levels. In patients undergoing L3-4 ACR-ALLR, a PI value of ≤53° is associated with a significantly elevated risk of PJF. Preoperative planning of ACR-ALLR level based on normal sagittal alignment in otherwise healthy individuals may mitigate the risk of PJF development in patients with adult spinal deformity treated with ACR-ALLR., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Sacroiliac joint dysfunction (SIJD) after lumbar/lumbosacral fusion has become increasingly recognized as the utilization of lumbar fusion has grown. Despite the significant morbidity associated with this condition, uncertainty regarding its diagnosis and treatment remains. We aim to update the current knowledge of the etiology, diagnosis, and treatment of post-lumbar surgery SIJD., Methods: PRISMA guidelines were used to search the PubMed/Medline, Web of Science, Cochrane Reviews, Embase, and OVID databases for literature published in the last 10 years. The ROBIS tool was utilized for risk of bias assessment. Statistical analyses were performed using the R foundation. A Fisher's exact test was performed to determine the risk of SIJD based on operative technique, gender, and symptom onset timeline. Odds ratios were reported with 95% confidence intervals. A p-value [Formula: see text] 0.05 was considered statistically significant., Results: Seventeen publications were included. The incidence of new onset SIJD was 7.0%. The mean age was 56 years, and the follow-up length was 30 months. SIJD was more common with fixed lumbar fusion vs floating fusion (OR = 1.48 [0.92, 2.37], p = 0.083), fusion of [Formula: see text] 3 segments (p < 0.05), and male gender increased incidence of SIJD (OR = 1.93 [1.27, 2.98], p = 0.001). Intra-articular injection decreased the Visual Analogue Scale (VAS) score by 75%, while radiofrequency ablation (RFA) reduced the score by 90%. An open approach resulted in a 13% reduction in VAS score versus 68 and 29% for SIJ fixation using the iFuse and DIANA approaches, respectively., Conclusions: Lumbar fusion predisposes patients to SIJD, likely through manipulation of the SIJ's biomechanics. Definitive diagnosis of SIJD remains multifaceted and a newer modality such as SPECT/CT may find a future role. When conservative measures are ineffective, RFA and SIJ fixation using the iFuse System yield the greatest improvement VAS and ODI., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Purpose: Over the past decade, alternative patient positions for the treatment of the anterior lumbar spine have been explored in an effort to maximize the benefits of direct anterior column access while minimizing the inefficiencies of single or multiple intraoperative patient repositionings. The lateral technique allows for access from L1 to L5 through a retroperitoneal, muscle-splitting, transpsoas approach with placement of a large intervertebral spacer than can reliably improve segmental lordosis, though its inability to be used at L5-S1 limits its overall adoption, as L5-S1 is one of the most common levels treated and where high levels of lordosis are optimal. Recent developments in instrumentation and techniques for lateral-position treatment of the L5-S1 level with a modified anterior lumbar interbody fusion (ALIF) approach have expanded the lateral position to L5-S1, though the positional effect on L5-S1 lordosis is heretofore unreported. The purpose of this study was to compare local and regional alignment differences between ALIFs performed with the patient in the lateral (L-ALIF) versus supine position (S-ALIF)., Methods: Retrospective, multi-center data and radiographs were collected from 476 consecutive patients who underwent L5-S1 L-ALIF (n = 316) or S-ALIF (n = 160) for degenerative lumbar conditions. Patients treated at L4-5 and above with other single-position interbody fusion and posterior fixation techniques were included in the analysis. Baseline patient characteristics were similar between the groups, though L-ALIF patients were slightly older (58 vs. 54 years), with a greater preoperative mean L5-S1 disk height (7.8 vs. 5.8 mm), and with less preoperative slip (6.6 vs. 8.5 mm), respectively. 262 patients were treated with only L-ALIF or S-ALIF at L5-S1 while the remaining 214 patients were treated with either L-ALIF or S-ALIF at L5-S1 along with fusions at other thoracolumbar levels. Lumbar lordosis (LL), L5-S1 segmental lordosis, L5-S1 disk space height, and slip reduction in L5-S1 spondylolisthesis were measured on preoperative and postoperative lateral X-ray images. LL was only compared between single-level ALIFs, given the variability of other procedures performed at the levels above L5-S1., Results: Mean pre- to postoperative L5-S1 segmental lordosis improved 39% (6.6°) and 31% (4.9°) in the L-ALIF and S-ALIF groups, respectively (p = 0.063). Mean L5-S1 disk height increased by 6.5 mm (89%) in the L-ALIF and 6.4 mm (110%) in the S-ALIF cohorts, (p = 0.650). Spondylolisthesis, in those patients with a preoperative slip, average reduction in the L-ALIF group was 1.5 mm and 2.2 mm in the S-ALIF group (p = 0.175). In patients treated only at L5-S1 with ALIF, mean segmental alignment improved significantly more in the L-ALIF compared to the S-ALIF cohort (7.8 vs. 5.4°, p = 0.035), while lumbar lordosis increased 4.1° and 3.6° in the respective groups (p = 0.648)., Conclusion: Use of the lateral patient position for L5-S1 ALIF, compared to traditional supine L5-S1 ALIF, resulted in at least equivalent alignment and radiographic outcomes, with significantly greater improvement in segmental lordosis in patients treated only at L5-S1. These data, from the largest lateral ALIF dataset reported to date, suggest that-radiographically-the lateral patient position can be considered as an alternative to traditional ALIF positional techniques., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: To date, the influence of Roussouly type on development of adjacent segment degeneration (ASD) after lumber fusion is still not fully explored, and the current study is aimed to evaluate the effect of Roussouly type on development of radiological ASD after single-level lumber fusion, and to compare the Roussouly types and spinopelvic parameters among those with different degenerative patterns of ASDs on sagittal plane., Methods: A retrospective review of 288 patients underwent L4/5 or L5/S1 single-level posterior interbody fusions between January 2016 and December 2018 with a minimum 2-year follow up was performed. Radiological ASDs were identified and divided into 3 groups according to different degenerative patterns of the cephalad adjacent level on sagittal plane, including the types of retrolisthesis (Group A), anterolisthesis (Group B), and axial disc space narrowing (Group C). Roussouly types and radiological measurements were compared among three groups and potential risk factors for ASD were evaluated., Results: Radiological ASD was found in 59 (20.5%) cases, in which patients with Roussouly type-2 was the most common. While, on subgroup analysis among three ASD groups, Roussouly type-1 occupied the highest proportion in Group A, differ in Group B and Group C, both with Type-2 as the most common. Moreover, Group A had significantly lower pelvic tilt (PT), larger sacral slope (SS), and larger segmental angle (SA) than Group B and Group C, which showed a more anteverted pelvic in Group A. Multivariate regression analysis noted Roussouly type, preoperative PT, and ∆PI-LL as the independent risk factors for radiological ASD., Conclusion: Roussouly type was significantly associated with the development of radiological ASD; however, the Roussouly types and spinal pelvic parameters were varied among different sagittal degenerative patterns of ASD, which was important in restoring optimal lumbar sagittal alignments in initial surgery., (© 2022. The Author(s).)

Purpose: The clinical and radiological results of adult spinal deformity (ASD) patients with a severe lumbar sagittal deformity undergoing multilevel lateral lumbar interbody fusion (LLIF) + posterior spinal fusion (PSF) were compared to patients undergoing three-column osteotomy (3CO)., Methods: We defined severe lumbar sagittal deformity as fulcrum backward bending (FBB) pelvic incidence minus lumbar lordosis (PI-LL) ≧ 20 degrees. A total of twenty-five patients with an ASD were enrolled between 2013 and 2018. Fifteen patients were in the LLIF + PSF group, and ten patients were in the 3CO group. We evaluated patient demographics, clinical outcomes, and radiographic parameters such as the Cobb angle and spinopelvic parameters from standing X-ray films in each group., Results: The LLIF + PSF group had a significantly shorter follow-up time than the 3CO group. Postoperatively, the LLIF + PSF group had significantly lower PI-LL and a shorter sagittal vertical axis than the 3CO group. Postoperative PI-LL changes in the LLIF + PSF group were significantly smaller than those in the 3CO group. There were no differences in other patient demographics, radiographic parameters, or clinical outcomes between the groups., Conclusion: Multilevel LLIF + PSF improved the PI-LL and SVA more than did 3CO for ASD patients with severe lumbar sagittal deformity. This indicated that the multilevel LLIF with open PSF can provide good clinical outcomes even in cases with severe lumbar sagittal deformity such as large FBB PI-LL in which 3CO techniques usually are needed., (© 2021. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background Context: Pedicle fractures are a rare but potentially devastating complication of posterior instrumented spinal fusion (PSF). Preoperative awareness of the possible risk factors may help prevent these fractures by modifying the surgical plan. However, the risk factors have not yet been identified., Purpose: To determine the preoperative parameters associated with postoperative L5 pedicle fracture after L4/5 PSF., Study Design: Case control study., Patient Sample: Patients undergoing L4/5 PSF at a single academic institution between 2014 and 2020., Outcome Measures: Occurrence of postoperative L5 pedicle fracture., Methods: Of 253 patients (female:male, 145:108) undergoing L4/5 PSF from 2014 to 2020, patients with postoperative L5 pedicle fractures were identified retrospectively as "cases" (n = 8, all female, age: 70 ± 10.7 years). As a control group all remaining patients with a follow-up of more than 12 months were allocated (n = 184, 104 females, age: 64.27 ± 13.00 years). In all but 16 cases, anterior support with transforaminal or posterior interbody fusion was performed. Demographic and clinical data (body mass index (BMI)), surgical factors, and comorbidities) were compared. Radiological assessment of spinopelvic parameters was performed using pre- and postoperative standing lateral radiographs., Results: The overall incidence of L5 pedicle fractures after L4/5 spinal fusion was 3.16%, with a median time from index surgery to diagnosis of 25 days (range, 6-199 days) (75% within the first 32 days postoperatively). Patients with L5 pedicle fractures had higher pelvic incidence (PI) (71° ± 9° vs. 56° ± 11°; p=.001), sacral slope (SS) (45° ± 7° vs. 35° ± 8°; p=.002), L5 slope (30° ± 11° vs. 15° ± 10°, p=.001), L5 incidence (42° ± 14° vs. 26° ± 11°; p= .003), L1-S1 lumbar lordosis (LL) postop (57° ± 10° vs. 45° ± 11°; p=.006), and L4 -S1 LL postop (33° ± 7° vs. 28° ± 7°; p=.049) compared with the control group. Pelvic tilt and PI- LL mismatch were not significantly different. Female gender was a significant risk factor for L5 pedicle fractures (p=.015). BMI (kg/m 2 ) was statistically equal in patients with or without pedicle fractures (28.37 ± 5.96 vs. 28.53 ± 16.32; p=.857). There was no significant difference between the groups for approximative bone mineral density assessment (Hounsfield units; 113 ± 60 vs. 120 ± 43; p=.396) using the L3 trabecular region of interest (ROI) measurement. The correlation analysis demonstrated that most of the identified risk factors except for the postoperative L4-S1 lordosis show significant positive associations among each other. All eight patients in the fracture group underwent revision surgery, and the instrumented fusion was extended to the sacrum, with the addition of sacral-alar-iliac or iliac screws, in six cases., Conclusions: L5 pedicle fractures occurred in 3% of the patients after single level L4/5 PSF. Risk factors are female gender, higher PI, SS, L5 slope, L5 incidence, and LL postop but not high BMI. These findings can be used for surgical planning and decision of fusion levels., Competing Interests: Declaration of Competing Interests The authors declare that they have no conflict of interest. No funding was received., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: To determine whether the L3-L4 disc angle may be a surrogate marker for global lumbar alignment in thoracolumbar fusion surgery and to explore the relationship between radiographic and patient-reported outcomes after thoracolumbar fusion surgery., Methods: Retrospective chart review was conducted on patients who had undergone a lumbar fusion involving levels from T9 to pelvis. EuroQol-Five Dimension (EQ-5D-3L) scores and adverse events including adjacent-segment disease and degeneration, pseudoarthrosis, proximal junctional kyphosis, stenosis, and reoperation were collected. Pre- and postoperative spinopelvic parameters were measured on weight-bearing radiographs, with the L3-L4 disc angle of novel interest. Univariate logistic and linear regression were performed to assess the associations of radiographic parameters with adverse event incidence and improvement in EQ-5D-3L, respectively., Results: In total, 182 patients met inclusion criteria. Univariable analysis revealed that increased magnitude of L3-L4 disc angle, anterior pelvic tilt, and pelvic incidence measures are associated with increased likelihood of developing postoperative adverse events. Conversely, increased lumbar lordosis demonstrated a decreased incidence of developing a postoperative adverse event. Linear regression showed that radiographic parameters did not significantly correlate with postoperative EQ-5D-3L scores, although scores were significantly improved postfusion in all dimensions except Self-Care (P = 0.51)., Conclusions: L3-L4 disc angle magnitude may serve as a surrogate marker of global lumbar alignment. The degree of spinopelvic alignment did not correlate to improvement in EQ-5D-3L score in the present study, suggesting that quality of life metric change may not be a sensitive or specific marker of postfusion alignment., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: The common manual measurement technique of spinal sagittal alignment on X-rays is susceptible to rater-dependent variability, which has not been adequately considered in previous publications. This study investigates the effect of those variations in the characterization of patients receiving lumbar spondylodesis., Methods: General alignment parameters on pre- and postoperative X-rays were evaluated by four raters in 43 prospectively sampled patients undergoing monolevel spondylodesis. The Intra-class Correlation Coefficient (ICC) for each rater pair and all raters together was calculated for inter-rater reliability. For the operation-induced change of the sagittal alignment in every patient the Wilcoxon test was applied to compare for each rater separately., Results: The ICCs were "good" (>0.75) to "excellent" (>0.9) for all raters together and for 45 of the 48 single rater pairs (93.75%). All revealed a significant increase of the addressed segmental lordosis and disc height and no significant change for spinopelvic parameters and sagittal vertical axis from pre- to postoperative. The lumbar lordosis showed a significant increase through the operation of +2.5° (p = 0.014) and +3.7° (p = 0.015) in two raters and no difference for the other ones (+2.1°, p = 0.171; -2.2°, p = 0.522)., Conclusions: The pre- to postoperative change of lumbar lordosis revealed different significance levels for different raters, although the ICCs were formally good. Accordingly, the evaluation by only one rater would lead to different conclusions. Due to this susceptibility of alignment measurements to rater-dependent variability, the exact evaluation process should be described in every publication and the consistency of significant results be validated through multiple raters., Trials Registration: The trial was approved by the local ethics committee and listed at the national clinical trials register ( DRKS00004514 , date of registration: 08/11/2012)., (© 2022. The Author(s).)

Objective: To investigate influences of spinopelvic parameters, such as lumbar lordosis (LL) angles, pelvic incidence, sacral slope, pelvic tilt, and sagittal vertical axis, on development of the proximal junctional failure fracture type after posterior instrumentation., Methods: This retrospective 1:3 matched case-control cohort study included 24 patients who developed proximal instrumented fracture in the study group and 72 patients without proximal junctional failure in the control group. Weighted Charlson Comorbidity Index and bone mineral density with T-score were recorded. In addition to spinopelvic parameters, proximal local kyphosis (PLK), which refers to a kyphosis angle between the upper end plate of upper instrumented vertebra plus 1 level and the lower end plate of upper instrumented vertebra; pelvic incidence-LL mismatch; and spinopelvic realignment score were calculated., Results: More comorbidities (Charlson Comorbidity Index, P = 0.002) and poorer bone density (T-score, P = 0.001) were noted in the study group. Before surgery, the study group had significantly lower LL (P = 0.046) and sacral slope (P = 0.043) and significantly higher PLK (P < 0.001) and pelvic tilt (P = 0.044) than the control group. Postoperatively, the study group had significantly higher PLK (P < 0.001) and lower LL (P = 0.031) than the control group; the degree of pelvic incidence-LL mismatch (P = 0.007) remained significantly higher in the study group. Preoperative (P = 0.026) and postoperative (P = 0.045) spinopelvic realignment scores was worse in the study group. Multivariate analysis revealed that postoperative PLK was the most significant radiographic factor to predict proximal instrumented fracture (P = 0.002, odds ratio 1.140, 95% confidence interval)., Conclusions: In our experience, appropriate LL and lower PLK should be obtained at surgery to prevent development of instrumented fracture., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Adult spinal deformities (ASD) represent a growing clinical condition related to chronic pain, disability and reduction in quality of life (QoL). A strong correlation among spinal alignment, spinopelvic parameters and QoL after spinal fusion surgery in ASD patients was thoroughly investigated over the last decade, However, only few studies focused on the relationship between lumbo-pelvic-femoral parameters - such as Femoral Obliquity Angle (FOA), T1 Pelvic Angle (TPA) and QoL., Methods: Radiological and clinical data from 43 patients surgically treated with thoracolumbar posterior spinal fusion for ASD between 2015 and 2018 were retrospectively analyzed. The primary outcomes were the correlation between preoperative spino-pelvic-femoral parameters and postoperative clinical, functional outcomes and QoL. Secondary outcomes were: changes in sagittal radiographic parameters spino-pelvic-femoral, clinical and functional outcomes and the rate of complications after surgery., Results: Using Spearman's rank correlation coefficients, spinopelvic femoral parameters (FOA, TPA, pre and post-operative) are directly statistically correlated to the quality of life (ODI, SRS-22, pre and post-operative; > 0,6 strong correlation, p <  0.05). Stratifying the patients according pre preoperative FOA value (High FOA ≥ 10 and Normal/Low FOA <  10), those belonging to the first group showed worse clinical (VAS: 5.2 +/- 1.4 vs 2.9 +/- 0.8) and functional outcomes (ODI: 35.6+/- 6.8 vs 23.2 +/- 6.5) after 2 years of follow-up and a greater number of mechanical complications (57.9% vs 8.3% p <  0.0021)., Conclusion: Based on our results, preoperative FOA and TPA could be important prognostic parameters for predicting disability and quality of life after spinal surgery in ASD patients and early indicators of possible spinal sagittal malalignment. FOA and TPA, like other and better known spinopelvic parameters, should always be considered when planning corrective surgery in ASD patients., (© 2021. The Author(s).)

Background: To date, there is a paucity of reports clarifying the change of spinopelvic parameters in patients with adult spinal deformity (ASD) who underwent long segment spinal fusion using iliac screw (IS) and S2-alar-iliac screw (S2AI) fixation., Methods: A retrospective review of consecutive patients who underwent deformity correction surgery for ASD between 2013 and 2017 was performed. Patients were divided into two groups based on whether IS or S2AI fixation was performed. All radiographic parameters were measured preoperatively, immediately postoperatively, and the last follow-up. Demographics, intraoperative and clinical data were analyzed between the two groups. Additionally, the cohort was subdivided according to the postoperative change in pelvic incidence (PI): subgroup (C) was defined as change in PI ≥5° and subgroup (NC) with change < 5°. In subgroup analyses, the 2 different types of postoperative change of PI were directly compared., Results: A total of 142 patients met inclusion criteria: 111 who received IS and 31 received S2AI fixation. The IS group (65.6 ± 26°, 39.8 ± 13.8°) showed a significantly higher change in lumbar lordosis (LL) and upper lumbar lordosis (ULL) than the S2AI group (54.4 ± 17.9°, 30.3 ± 9.9°) (p < 0.05). In subgroup (C), PI significantly increased from 53° preoperatively to 59° postoperatively at least 50% of IS cohort, with a mean change of 5.8° (p < 0.05). The clinical outcomes at the last follow-up were significantly better in IS group than in S2AI group in terms of VAS scores for back and leg. The occurrence of sacroiliac joint pain and pelvic screw fracture were significantly greater in S2AI group than in IS group (25.8% vs 9%, p < 0.05) and (16.1% vs 3.6%, p < 0.05)., Conclusions: Compared with the S2AI technique, the IS technique usable larger cantilever force demonstrated more correction of lumbar lordosis, and possible increase in pelvic incidence. Further study is warranted to clarify the clinical impaction of these results., (© 2021. The Author(s).)

Purpose: Long time recognized as a cause of lumbar stenosis, degenerative spondylolisthesis has an evolution in interrelation with sagittal balance. This study aimed to assess the role of ALIF in correcting the sagittal balance in patients with degenerative spondylolisthesis., Material and Methods: Twenty patients aged between 47 and 70 years were operated between July 2011 and September 2014 for degenerative spondylolisthesis by ALIF. The pre-operative and post-operative valid standing full spine radiographs were reviewed retrospectively. Clinical and radiological evaluations were conducted pre-operatively and postoperatively at one year and five years., Results: Lumbar lordosis (LL) was measured to 41.16 ± 14.25° pre-operatively and 47.27 ± 11.25° post-operatively (p > 0.05). At one year was 49.76 ± 13.31° and at five years 46.93 ± 9.26° (p > 0.05). Mean gain of lordosis after ALIF at index level was calculated to 8 ± 1.6° [4-12°]., Conclusions: ALIF offers a good reduction of the slipped vertebra providing good conditions for fusion and is an efficient surgical technique to recreate the sagittal spine balance.

Purpose: We aim at analysing the impact of anterior lumbar interbody fusion (ALIF) in restoring the main spinopelvic parameters, along with its potentials and limitations in correcting sagittal imbalance., Materials and Methods: The 2009 PRISMA flow chart was used to systematically review the literature; 27 papers were eventually selected. The following spinopelvic parameters were observed: pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), segmental lumbar lordosis (LLseg) and sagittal vertical axis (SVA). Papers reporting on hyperlordotic cages (HLC) were analysed separately. The indirect decompression potential of ALIF was also assessed. The clinical outcome was obtained by collecting visual analogue scale (VAS) for back and leg pain and Oswestry Disability Index (ODI) scores. Global fusion rate and main complications were collected., Results: PT, SS, LL, LLseg and SVA spinopelvic parameters all improved postoperatively by - 4.3 ± 5.2°, 3.9 ± 4.5°, 10.6 ± 12.5°, 6.7 ± 3.5° and 51.1 ± 44.8 mm, respectively. HLC were statistically more effective in restoring LL and LLseg (p < 0.05). Postoperative disc height, anterior disc height, posterior disc height and foraminal height, respectively, increased by 58.5%, 87.2%, 80.9% and 18.1%. Postoperative improvements were observed in VAS back and leg and ODI scores (p < 0.05). The global fusion rate was 94.5 ± 5.5%; the overall complication rate was 13%., Conclusion: When managing sagittal imbalance, ALIF can be considered as a valid technique to achieve the correct spinopelvic parameters based on preoperative planning. This technique permits to obtain an optimal LL distribution and a solid anterior column support, with lower complications and higher fusion rates when compared to posterior osteotomies.

Introduction: Lumbar and lumbosacral spinal fusion is an established procedure for the treatment of degenerative spondylolisthesis. However, the impact of reduction in the affected segment and of improvement in the radiological sagittal parameters on the clinical outcome remains unclear. Purpose of the study is to analyze the correlation between the radiological sagittal parameters and clinical outcome after lumbar spinal fusion in low-grade degenerative spondylolisthesis., Materials and Methods: In a monocentric prospective, clinical study, patients with low-grade degenerative spondylolisthesis of a single lumbar segment have been included. All patients received a lumbar spinal fusion according to the pathology of the treated segment. Patients attended clinical and radiological follow-up examination 1 and 2 years postoperatively. Clinical outcome was assessed using the Core Outcome Measurement Index (COMI), the Oswestry Disability Index (ODI) and the EuroQol 5D. The sagittal spinopelvic radiological parameters, sagittal rotation and anterior displacement of the affected segment and lumbar lordosis were assessed. The correlation between the sagittal radiological parameters and clinical outcome was analyzed using Spearman-Rho bi-serial test., Results: Sixty-two patients (35 female and 27 male) with an average age of 59.3 years were included in the study. All patients completed the follow-up examinations. Significant improvement in COMI, ODI and EuroQol 5D scores was shown in all follow-up examinations. Significant reduction in the anterior displacement was measured postoperatively, which was preserved during the follow-up. However, no correlation could be demonstrated between reduction in anterior displacement and improvement in clinical outcome. Nonetheless, correlation between correction of sagittal rotation and clinical outcome was shown., Conclusions: Reduction in anterior displacement of the affected segment in the surgical treatment of low-grade degenerative spondylolisthesis does not have an impact on the clinical outcome.

Anterior lumbar interbody fusion (ALIF) combined with posterior column osteotomy (PCO) may be effective to achieve ideal lumbar curve correction in lumbar flat-back deformity (LFD). We aimed to investigate the radiographic and clinical outcomes of patients with primary degenerative LFD treated with multi-level ALIFs combined with PCOs. Seventy patients with primary degenerative LFD who underwent corrective surgery were divided into three groups according to the 1-month postoperative pelvic incidence/lumbar lordosis (PI-LL) angles (≤ - 10°, from - 9° to 9°, and ≥ 10°). The spinopelvic parameters, including thoracic kyphosis, LL, pelvic tilt, T1 pelvic angle, and sagittal vertical axis, were analyzed at the preoperative, postoperative follow-up periods. The clinical outcomes, including the Oswestry disability index (ODI), visual analog scale (VAS), and Scoliosis Research Society (SRS)-22r, were also evaluated. Further, the paraspinal muscles were qualitatively and quantitatively examined, preoperatively. All spinopelvic parameters were corrected as close to the normal values at the 1-month postoperative period. The spinopelvic parameters in the PI-LL ≤ - 10° group were better corrected and maintained than those in the other groups. The ODI, VAS, and SRS-22r scores improved at the final follow-up in all groups. The PI-LL ≤ - 10° group showed better clinical outcomes than the other groups. In the paraspinal muscle examination, the mean lumbar muscularity value and fatty degeneration ratio were 236.7% and 20.7%, respectively. Multi-level ALIFs with PCOs in patients with LFD are effective in restoring sagittal balance and improving clinical symptoms. In addition, the postoperative LL angles should be larger than PI + 10° to achieve good overall outcomes in patients with severe degenerative back muscle.

Background/context: Degenerative lumbar disease can be addressed via an anterior or posterior approach, and with or without the use of an interbody cage. Although several studies have compared the type of approach and technique, there is a lack of literature assessing patient-reported outcome measures (PROMs) and radiographic parameters between different fusion techniques., Purpose: To determine whether the surgical approach and fusion technique for lumbar degenerative disease had an effect on short-term PROMs and radiographic parameters., Study Design/setting: Retrospective Cohort Study., Patient Sample: Three hundred and ninety-one patients who underwent a 1-3 level lumbar spine fusion procedure at a high-volume academic center were retrospectively identified. Patients were divided into three groups based on the type of fusion they underwent: posterolateral fusion (PLF), anterior lumbar interbody fusion (ALIF), or transforaminal lumbar interbody fusion (TLIF)., Outcome Measures: PROMs: Short Form-12 (SF-12) Physical Component Score (PCS) and Mental Component Score (MCS), Oswestry Disability Index (ODI), Visual Analog Score (VAS) Back, VAS Leg. Spinopelvic measurements: Pelvic Tilt (PT), Sacral Slope (SS), Pelvic Incidence (PI), Lumbar Lordosis (LL), Segmental Lordosis (SL), PI-LL mismatch., Methods: Patients with less than 1-year follow-up were excluded from the cohort. Pre- and postoperative spinopelvic measurements were obtained for all patients. Univariate analysis (Chi-squared/Fisher's exact test or ANOVA test with post-hoc Bonferroni test) was used to compare among the three groups in the PROMs and radiographic spinopelvic parameters. Multiple linear regression was used to determine if fusion technique was an independent predictor of change in each patient outcome., Results: Two hundred and sixteen patients were included in the PLF group, 33 patients in the ALIF group, and 142 patients in the TLIF group. The PLF group was significantly older at baseline (p<.001) and had lower preoperative diagnosis rates of degenerative scoliosis and disc herniations (p<.001), whereas the ALIF group underwent a higher proportion of three-level fusions (p<.001). There was no significant difference in spinopelvic parameters preoperatively, however the ALIF group showed significantly more improvement in SL postoperatively (p=.004) than the PLF and TLIF groups. Within each group, SL improved for the PLF and ALIF groups (p=.002 for both), but not for the TLIF group (p=.238). Comparing patient outcomes, the ALIF group reported lower preoperative VAS Leg scores (p=.031), however, this difference resolved postoperatively. Stratifying for preoperative diagnosis, there were no significant differences in outcomes, except for a greater improvement in VAS Leg scores for degenerative scoliosis patients undergoing ALIF. Using multivariate analysis, fusion technique was not found to be a significant predictor of change in any patient outcome or in odds of revision., Conclusions: Lumbar degenerative disease can be treated with several different fusion techniques, however, the relationship between type of fusion and PROMs is not established. Based on the findings in this study, the ALIF group showed greater improvement in SL compared with the PLF and TLIF groups, however, there was no difference noted in overall LL, PI-LL mismatch or other spinopelvic parameters. Despite these radiographic findings, patient outcome measures remained similar between all three fusion types., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Aim: The objective of this study is to determine the impact of postoperative spinopelvic parameters on the development of adjacent segment instability after single-level lumbar fusion., Material and Methods: A total of 116 patients with degenerative spine conditions after lumbar fusion were enrolled in this study and subdivided into two groups. Group I consisted of 24 patients with signs of adjacent segment instability; Group II included 92 patients without signs of instability. The minimal follow-up period was 24 months., Results: The mean postoperative lumbar lordotic (LL) angle in both groups was within the normal range (-60.9±12); no statistically significant intergroup differences were revealed (56.6±12.1 and 58.4±11.2 for Groups I and II, respectively; p=0.314). In Group I patients, the mean pelvic incidence (PI) angle differed significantly from the mean PI values in Group II patients (70.4±7.6 and 53.2±8.4, respectively; p=0.006) and from the normal PI values (51.9±10). Therefore, the mean difference between PI and LL (PI-LL) angles in the Group I patients was significantly higher than in Group II (16.2±5.4 and 4.8±8.6, respectively; p=0.004). Significant PI-LL mismatch (PI-LL ≥10°) was observed in 22 (91.7%) patients in Group I and in 11 (11.95%) patients in Group II. According to regression analysis data, the PI-LL mismatch was identified as a risk factor for adjacent segment instability; the odds ratio =4.2; 95% confidence interval 1.46-12.25; and p=0.007., Conclusion: Patients with the high PI value and low LL value have a significantly higher risk of adjacent segment instability after short-segment spinal fusion.

Background: The subsequent L5-S1 disc degeneration associated with long fusion arthrodesis terminating at L5 in patients with adult scoliosis has been a common concern. However, few studies paid attention to its preoperative predictors, especially in spinopelvic parameters. The purpose of the present study was to clarify the preoperative predictors of subsequent L5-S1 disc degeneration after long fusion arthrodesis terminating at L5 in patients with adult scoliosis on spinopelvic parameters., Methods: In this retrospective study, we enrolled 67 patients with adult scoliosis, and the patients were divided into disc degeneration group (DD) and no disc degeneration group (NDD), based on the presence or absence of subsequent L5-S1 disc degeneration. The status of L5-S1 disc was evaluated by a modified version of radiographic classification. Characteristics and spinopelvic parameters of preoperative patients were collected as potential predictors for subsequent lumbosacral disc degeneration after long fusion arthrodesis terminating at L5 in patients with adult scoliosis. Multivariate logistic regression analysis and the receiver operating characteristic curve were used to identify the preoperative predictors, with an adjusted odds ratio (OR) and 95% confidence intervals (CI)., Results: Thirty-six patients (53.73%) with subsequent L5-S1 disc degeneration were divided into group DD (preoperative score 0.81 ± 0.57, last follow-up score 1.83 ± 0.60, P <  0.001), and the other 31 patients were divided into group NDD (preoperative and last follow-up score 0.87 ± 0.49). There was no statistical difference in preoperative score (P = 0.583) of lumbosacral disc between two groups; however, significant statistical difference showed in last follow-up score (P <  0.001). Multivariate logistic regression identified three preoperative predictors: pelvic incidence (PI) (P = 0.018), sagittal vertical axis (SVA) (P = 0.024), and sacrum-femoral distance (SFD) (P = 0.023). PI < 48.5° (OR = 0.911, 95% CI = 0.843-0.984), SVA > 4.43 cm (OR = 1.308, 95% CI = 1.036-1.649), and SFD > 5.65 cm (OR = 1.337, 95% CI = 1.041-1.718) showed satisfied accuracy for predicting subsequent L5-S1 disc degeneration., Conclusion: The prevalence of the subsequent L5-S1 disc degeneration after long fusion arthrodesis terminating at L5 in patients with adult scoliosis was 57.3% (36 of 67 patients). PI < 48.5°, SVA > 4.43 cm, and SFD > 5.65 cm were preoperative predictors for the subsequent L5-S1 disc degeneration. More attention should be paid to prevent the L5-S1 disc from degeneration when these preoperative predictors exist, especially with two or more.

Study Design: Meta-analysis., Objective: To conduct a meta-analysis investigating the relationship between spinopelvic alignment parameters and development of adjacent level disease (ALD) following lumbar fusion for degenerative disease. ALD is a degenerative pathology that develops at mobile segments above or below fused spinal segments. Patient outcomes are worse, and the likelihood of requiring revision surgery is higher in ALD compared to patients without ALD. Spinopelvic sagittal alignment has been found to have a significant effect on outcomes post-fusion; however, studies investigating the relationship between spinopelvic sagittal alignment parameters and ALD in degenerative lumbar disease are limited., Methods: Six e-databases were searched. Predefined endpoints were extracted and meta-analyzed from the identified studies., Results: There was a significantly larger pre-operative PT in the ALD cohort versus control (WMD 3.99, CI 1.97-6.00, p = 0.0001), a smaller pre-operative SS (WMD - 2.74; CI - 5.14 to 0.34, p = 0.03), and a smaller pre-operative LL (WMD - 4.76; CI - 7.66 to 1.86, p = 0.001). There was a significantly larger pre-operative PI-LL in the ALD cohort (WMD 8.74; CI 3.12-14.37, p = 0.002). There was a significantly larger postoperative PI in the ALD cohort (WMD 2.08; CI 0.26-3.90, p = 0.03) and a larger postoperative PT (WMD 5.23; CI 3.18-7.27, p < 0.00001)., Conclusion: The sagittal parameters: PT, SS, PI-LL, and LL may predict development of ALD in patients' post-lumbar fusion for degenerative disease. Decision-making aimed at correcting these parameters may decrease risk of developing ALD in this cohort. These slides can be retrieved under Electronic Supplementary Material.

Acquired spondylolysis represents an uncommon complication of spine surgery, of an unknown incidence and etiology. We studied patients presenting this rare entity, with the purpose to investigate the incidence, imaging findings, patients' clinical characteristics, as well as to provide an interpretation of the mechanisms that may lead to this phenomenon. The presented working hypothesis, regarding etiology, suggests that there is a relation between variations in spinopelvic sagittal alignment and acquired spondylolysis. Between January 2010 and January 2015, six patients presented spondylolysis after short-segment transforaminal lumbar interbody fusion, at a mean time of 43 months after surgery. The preoperative intactness and postoperative defect of pars interarticularis were documented with computed tomography scans in all patients. Standard radiographical spinopelvic parameters were measured before and after surgery. The optimum values of lumbar lordosis (LL) and pelvic incidence minus lumbar lordosis modifier (PI-LL mismatch) were calculated as well. The incidence of acquired spondylolysis was 0.95% among patients with short-segment lumbar fusion. Patients presented high-grade PI with a vertically orientated sacral endplate, while LL was found 9° greater and PI-LL mismatch 9° lower than the respective optimum values, indicating a non-harmonized alignment. In conclusion, acquired spondylolysis, though rare, may occur in patients with high-grade PI and sacral slope, and suboptimal spinopelvic sagittal alignment after lumbar spine surgery, thereby highlighting the importance of detailed preoperative planning in spine surgery, along with the study of sagittal balance.

Background Context: Pelvic incidence (PI)=pelvic tilt (PT)+sacral slope (SS) is an established trigonometric equation which can be expanded from studying the fixed pelvis with the spine to a fixed spinopelvic complex with the remnant spine, in scenarios of spinopelvic fusion or ankylosis. For a fixed spinopelvic complex, we propose the equation termed: lumbar incidence (LI)=lumbar tilt (LT)+lumbar slope (LS)., Purpose: This study aimed to establish reference values for LI, LT, and LS at each lumbar vertebral level, and to show how LI can be used to determine residual lumbar lordosis (rLL)., Study Design: This is a cross-sectional study of prospectively collected data, conducted at a single academic tertiary health-care center., Patient Sample: The study included 53 healthy patients aged 19-35 with first episode mechanical low back pain for a period of <3 months. Patients with previous spinal intervention, those with known or suspected spinal pathologies, and those who were pregnant, were excluded., Outcome Measures: Radiological measurements of LI, LT, LS, and rLL., Methods: All patients had full-body lateral standing radiographs obtained via a slot scanner. Basic global and regional radiographic parameters, spinopelvic parameters, and the aforementioned new parameters were measured. LI was correlated with rLL at each level by plotting LI against rLL on scatter plots and drawing lines-of-best-fit through the datapoints., Results: The mean value of L5I was 22.82°, L4I was 6.52°, L3I was -0.92°, L2I was -5.56°, and L1I was -5.95°. LI turns negative at L3, LS turns negative at the L3/L4 apex, and LT remains positive throughout the lumbar spine. We found that the relationship of LI with its corresponding rLL follows a parabolic trend. Thus, rLL can be determined from the linear equations of the tangents to the parabolic lumbar spine. We propose the LI-rLL method for determining rLL as the LI recalibrates via spinopelvic compensation post instrumentation, and thus the predicted rLL will be based on this new equilibrium, promoting restoration of harmonized lordosis. The rLL-to-LI ratio is a simplified, but less accurate, method of deriving rLL from LI., Conclusions: This study demonstrates the extended use of PI=PT+SS proposed as LI=LT+LS. These new spinopelvic reference values help us better understand the position of each vertebra relative to the hip. In situations when lumbar vertebrae are fused or ankylosed to the sacrum to form a single spinopelvic complex, LI can be used to determine rLL, to preserve spinal harmony within the limits of compensated body balance., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Due to the obstruction of the iliac crest and the retroperitoneal vessels, lateral lumbar interbody fusion (LLIF) is generally considered contraindicated at the lumbosacral junction (LSJ). In particular the 'rise' of the psoas from the vertebral column in the lower lumbar segments has been associated with significant overlap of the lumbar plexus with the vertebral body and exclusion of a safe transpsoas entry. However in selected individuals anatomical variations may help circumvent the difficulties and the anatomical corridor posterior to the lumbar plexus may provide an alternative to the conventional anterior approach. Currently there is a dearth of information in informing the feasibility. We therefore reviewed the records of three patients in whom LLIF was successfully conducted at the LSJ. The patients' spinopelvic parameters and psoas anatomy were analysed by whole spine standing X-rays and MRI respectively. Intraoperative findings and postoperative outcome were examined. We found that in keeping with published morphometric data, low pelvic incidence (40-50°) appeared associated with 'low-lying' iliac crests which had facilitated lateral access to the LSJ in all cases. Patients with scoliosis provided added advantage when the concave side of the curve was utilised for the approach. A very high 'rising' psoas was found conducive to a novel posterior surgical corridor. No significant neurovascular sequelae were noted. In conclusion, LLIF can be safely performed at the LSJ in selected cases. To our knowledge this is the first report to describe the possibility of a safe LLIF working zone posterior to the lumbar plexus., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: The Lenke classification is well established in differentiation of curve types in adolescent idiopathic scoliosis (AIS) and guides selection of fusion levels. However, to date, it has neglected the spinopelvic parameters that have been associated with compensatory mechanisms in balancing the human erect posture and adjacent segment problems after spinal fusion. The aim of this study was to investigate spinopelvic parameters in different types of AIS curves., Material and Methods: Preoperative whole-spine radiographs from 100 patients with AIS were reviewed and the curves were classified according to Lenke. In addition, sagittal spinopelvic parameters (pelvic incidence, sacral slope, pelvic tilt) were measured and compared between different curve types and to normal population values., Results: The spinopelvic balance was not statistically distinguishable in different Lenke curve types. Slight differences of the spinopelvic balance, compared with normal population values, were found in AIS Lenke Type 5 and 6 curves (major curve at the lumbar/thoracolumbar region) with a pelvic incidence of 44° ± 8° (norm 49°), sacral slope of 34° ± 7° (norm 41°), and pelvic tilt of 10° ± 7° (norm 8°)., Conclusion: Overall, the variances of spinopelvic parameters in different AIS curve types do not seem statistically large enough for a potential clinical relevance. However, the sacrum is more verticalized in AIS curves with major curves located in the lumbar/thoracolumbar region. It remains to be investigated whether such a verticalized sacrum might be a compensatory mechanism to keep the whole spine balanced and if it reverses with correction of the scoliosis., (Copyright © 2016 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.)

Purpose: To analyze changes in sagittal spinopelvic parameters (SSPs) after surgical treatment of Scheuermann's Kyphosis (SK)., Methods: We analyzed 20 patients affected by SK and subjected to posterior correction of the kyphosis by facetectomy, Ponte osteotomy, fusion and multilevel instrumentation with pedicle screw system. Four spinal and three pelvic parameters were measured: sagittal vertical axis (SVA), thoracic kyphosis (TK), thoracolumbar kyphosis, lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS) and pelvic tilt (PT). Analysis of changes in postprocedural SSPs compared to preoperative values was performed., Results: TK passed from 78.6° preoperatively to 45.8° (p = 0.003). LL passed from 74.5° preoperatively to 53.5° (p = 0.01). No significant changes occurred in SVA, SS, PT and PI compared to preoperative values., Conclusion: We confirm the positive effect of surgery by Ponte osteotomy and posterior spinal fusion on TK and LL in patients with SK. In our experience, pelvic parameters did not change after surgery.

Abstract Spinal surgery continues to expand its horizons to care for disabled patients presenting pain and deformities. Over the past decade, our knowledge of spinal alignment, from the skull to the pelvis, has increased considerably. Such knowledge must expand to reach general orthopedists and improve the care required for so many people. Global spinal alignment is a critical concept in understanding the impact of pathological conditions (degenerative diseases, traumas, deformities) and their treatment, including spinal instrumentation and arthrodesis. Therefore, the treatment of any spinal disease must include the knowledge of the complexity of the spinopelvic alignment. At first, all parameters seem like pure mathematics, hardly applicable to the everyday life of the inattentive reader. However, it gradually becomes clear that, like everything else in orthopedics, biomechanics is an essential part of the knowledge of the musculoskeletal system, revealing the logic behind the physiology of movements. The knowledge of the sagittal alignment concepts and spinopelvic parameteres provide a better comprehension of the axial and appendicular skeletons, increasing the understanding of the physiological and adaptive spinal processes in the face of the degenerative process that increases throughout life.

aim of this study is to acknowledge whether reduction surgery for degenerative lumbar spondylolisthesis (DLS) using long arm pedicle screws is able to correct the listhesis and spinopelvic parameters. Methods: We carried out a retrospective study of patients with degenerative lumbar spondylolisthesis who went through reduction surgery using long arm pedicle screws in our institutions from January 2019 to March 2022. Preoperative and postoperative radiological outcomes consisting of listhesis and spinopelvic parameters were assessed. Results: We found a statistical difference between the magnitude of listhesis immediately after surgery and preoperatively (p< 0.001), with a successful correction of 85.85%. There was significant decrease in the value of pelvic tilt (p=0.044) and increase in the value of sacral slope (p=0.008) after surgery. Conclusion: Reduction surgery using long arm pedicle screws for DLS was able to reduce the listhesis effectively up to 85.5%, and also to restore the parts of spinopelvic parameters, the pelvic tilt and sacral slope, approaching normal values. [ABSTRACT FROM AUTHOR]

Study Design: Systematic review and meta-analysis.Objective: The purpose of the study was to compare the outcomes and after spinal fusion with or without iliac screw (IS) insertion for patients with adult spinal deformity (ASD).Summary Of Background Data: The number of patients undergoing multilevel spinal stabilization for the treatment of ASD is growing. However, the selection of spinopelvic fixation for ASD patients with long fusion is controversial.Methods: A comprehensive literature search was performed without time restriction according to the guidelines from the Cochrane Collaboration in May 2020 using PubMed, EMBASE, and the Cochrane Library. The comparison of the two types of fixation was evaluated by spinopelvic parameters, incidence rate of complications, rate of revision, and clinical outcomes at the last follow-up.Results: The literature search identified 422 records, of which eight studies were included for meta-analysis with a total of 439 patients. All the included studies provided level III evidence. There was no significant difference in the sagittal vertical axis, pelvic incidence, the proximal junctional kyphosis rates, the pseudarthrosis rates, the revision rates, and the clinical outcomes at the last follow-up between those who receive sacrum fixation and sacropelvic fixation. Nevertheless, greater lumbar lordosis (LL) (weighted mean difference [WMD], 4.15; 95% confidence interval [CI] 2.46-5.84, P < 0.01), greater sacral slope (SS) (WMD, 2.32; 95% CI 1.21-3.43, P < 0.01), and lower rate of the distal instrumentation instability (odds ratio, 0.25; 95% CI 0.10-0.61, P = 0.002) were observed in IS group between the comparison.Conclusion: The clinical outcomes in the IS group were similar to those in the non-IS group, but the application of the IS significantly restored LL, prevented decompensation, and reduced the occurrence of the distal instrumentation instability. Therefore, the IS may be a good choice for the operative treatment of ASD patients with sagittal malalignment and other risks of lumbosacral fracture, metal breakage, and screw pullout.Level of Evidence: 3. [ABSTRACT FROM AUTHOR]

Study DesignRetrospective study (level of evidence: level 3).PurposeThe purpose of this study was to evaluate the clinical and radiological results of the posterior-only approach with pedicle screws for the treatment of Scheuermann's kyphosis (SK).Overview of LiteratureThe correction of SK with instrumentation can be performed using posterior-only or combined anterior-posterior procedures. With the use of all-pedicle screw constructs in spine surgery, the posterior-only approach has become a popular option for the definitive treatment of SK. In a nationwide study involving 2,796 patients, a trend toward posterior-only fusion with lower complication rates was reported.MethodsWe retrospectively reviewed the data of patients who underwent posterior-only correction for SK between January 2005 and May 2013. Patients with a definite diagnosis of SK who fulfilled the minimum follow-up criterion of 24 months were included. The thoracic kyphosis (T5–T12), lumbar lordosis (L1–S1), and thoracolumbar junction (T10–L2) angles were measured from preoperative, postoperative, and last control radiographs. Sagittal balance, thoracic length, thoracic diameter, Voutsinas index and the sacral slope, pelvic tilt, proximal junction kyphosis, and distal junction kyphosis angles were also measured.ResultsForty-five patients underwent surgery for the treatment of SK between 2005 and 2013. After applying the exclusion criteria, 20 patients (18 males and 2 females) with a mean age of 19 years were included. The mean thoracic kyphosis angle was 79.8 degrees preoperatively, 44.6 degrees postoperatively, and 44.9 degrees at the last control. There were statistically significant differences between preoperative and postoperative values in the thoracic kyphosis and lumbar lordosis angles, thoracic length, thoracic diameter, and Voutsinas index (p

Study Design: Retrospective study. Purpose: Associations among risk factors related to adjacent segmental disease (ASD) remain unclear. We evaluated the risk factors and segmental lordosis ratio to prevent ASD developing after lumbar spinal fusion. Overview of Literature: Risk factors related to ASD development are age, sex, obesity, pre-existing degeneration, number of fusion segments, and decreased postoperative lumbar lordosis (LL). However, the associations among these factors are still unclear and should be clearly identified. Methods: We retrospectively reviewed data on 274 patients who underwent lumbar spinal fusion of three segments or below for lumbar degenerative disease from January 2010 to December 2012, with over 5 years of follow-up. Patients with preoperative sagittal vertical axis (SVA) >5 cm were excluded due to sagittal imbalance. A total of 37 patients with ASD and 40 control patients (CTRL) were randomly selected in a similar distribution of matching variables: age, sex, and preoperative degenerative changes. Sex, age, number of fusion segments, radiologic measurements, L4-5-S1/L1-S1 LL ratio, and spinopelvic parameters (pelvic incidence [PI], pelvic tilt [PT], sacral slope [SS], and SVA) were analyzed. Logistic regression was used to analyze the correlation between PI-LL mismatch and L4-5-S1 segmental lordosis rate. Results: No significant difference was found between ASDs and CTRL groups regarding age, sex, number of fusion segments, fusion method, and preoperative and postoperative spinopelvic parameters (PI, SS, PT, and LL). However, regarding the L4-5-S1/L1-S1 lordosis ratio, 50% (p =0.045), 60% (p =0.031), 70% (p =0.042), 80% (p =0.023), and 90% (p =0.023) were statistically significant; <20% (p =0.478), 30% (p =0.223), and 40% (p =0.089) were not statistically significant. In the postoperative PI-LL <10 group, ASD occurred less frequently than in the PI-LL >10 group, and the difference was statistically significant (p =0.048). Conclusions: Patients with a postoperative L4-5-S1/L1-S1 lordosis ratio >50% had less occurrence of ASD. Correcting LL according to PI and physiologic segmental lordosis ratio is important in preventing ASD. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective study (level of evidence: level 3). Purpose: The purpose of this study was to evaluate the clinical and radiological results of the posterior-only approach with pedicle screws for the treatment of Scheuermann's kyphosis (SK). Overview of Literature: The correction of SK with instrumentation can be performed using posterior-only or combined anteriorposterior procedures. With the use of all-pedicle screw constructs in spine surgery, the posterior-only approach has become a popular option for the definitive treatment of SK. In a nationwide study involving 2,796 patients, a trend toward posterior-only fusion with lower complication rates was reported. Methods: We retrospectively reviewed the data of patients who underwent posterior-only correction for SK between January 2005 and May 2013. Patients with a definite diagnosis of SK who fulfilled the minimum follow-up criterion of 24 months were included. The thoracic kyphosis (T5-T12), lumbar lordosis (L1-S1), and thoracolumbar junction (T10-L2) angles were measured from preoperative, postoperative, and last control radiographs. Sagittal balance, thoracic length, thoracic diameter, Voutsinas index and the sacral slope, pelvic tilt, proximal junction kyphosis, and distal junction kyphosis angles were also measured. Results: Forty-five patients underwent surgery for the treatment of SK between 2005 and 2013. After applying the exclusion criteria, 20 patients (18 males and 2 females) with a mean age of 19 years were included. The mean thoracic kyphosis angle was 79.8 degrees preoperatively, 44.6 degrees postoperatively, and 44.9 degrees at the last control. There were statistically significant differences between preoperative and postoperative values in the thoracic kyphosis and lumbar lordosis angles, thoracic length, thoracic diameter, and Voutsinas index (p <0.05). Conclusions: The clinical and radiological results of the current study suggest that posterior-only fusion is an efficient technique for the treatment of SK. [ABSTRACT FROM AUTHOR]

Abstract: Background context: Fixed sagittal imbalance (FSI) may result from loss of adequate lumbar lordosis (LL) after spinal fusion. Pelvic incidence (PI) is a fixed anatomical parameter that determines LL and overall spinal sagittal alignment. Purpose: We describe the spinopelvic parameters in a series of patients with postfusion FSI. We hypothesize that patients who develop postfusion FSI may have a high PI and are thus more at risk from a loss of adequate LL. Study design: Retrospective chart and image review. Patient sample: Consecutive patients with degenerative spine disease with clinically significant postoperative FSI after fusion. Methods/outcome measures: We evaluated 36-in full spine films for PI, LL, pelvic tilt (PT), thoracic kyphosis (TK), and C7 plumb line. Results: Fifteen patients with clinically significant FSI were identified: 13 women and 2 men (mean age, 63.3 years). They had undergone a mean of 2.9 prior spine surgeries. The mean PI was elevated at 66.7° (normal 48–55°), mean PT was elevated at 35.5° (normal 12–18°), mean LL was reduced at 11.8° (normal 43–61°), mean TK was reduced at 19.3° (normal 41–48°), and mean C7 plumb line was elevated at 13.1cm (normal <3cm). Conclusions: In the current series, patients with FSI after spinal fusion had an elevated PI and inadequate LL. They attempted to compensate for FSI with reduced TK and with increased pelvic retroversion (PT). Overall, it is important to identify sagittal spinopelvic parameters and promote sagittal balance when performing lumbar fusions. [Copyright &y& Elsevier]