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Abstract Objective To specifically evaluate the safety and benefit of different drainage removal criteria (50 ml and 100 ml per 24 h) in patients undergoing short-level lumbar fusion surgery. Methods Patients with degenerative lumbar diseases who underwent short level lumbar fusion with instrumentation between January 2021 and January 2023 were retrospectively recruited in the study. Based on the different criteria for drainage removal, the patients were divided into 2 groups (group A and group B). To control for confounding factors, a 1:1 nearest propensity score matching of significant variation, especially age, gender, BMI, number of fused levels, intraoperative blood loss, and surgical duration, were performed between groups. Perioperative outcomes were compared between groups. Multivariate logistic regression was performed to determine the risk factors for overall complications. Results A total of 1004 eligible patients were reviewed in this study with 676 patients in group A and 328 patients in group B. After propensity score matching, 616 patients, 308 in each group were included in the final analysis. There were significantly more patients getting drainage removed on POD 2 (23.1% vs. 32.1%, p = 0.012) and POD 3 (37.0% vs., 45.1%, p = 0.041) in group B. In addition, patients in group B had earlier postoperative timing of ambulation (3.87 ± 1.12 vs. 2.41 ± 1.34, p = 0.012). No significant difference in symptomatic hematoma and surgical site infection was observed, but there were significant fewer overall complications (10.39% vs. 5.19%, p = 0.016) in the group B. Multivariate logistic regression indicated that postoperative timing of ambulation (OR 2.38, 95% CI 1.19–3.97, p

Abstract Background Lumbar disc degeneration (LDD) is a ubiquitous finding in low back pain. Many different etiology factors may explain the LDD process, such as bone morphogenetic proteins (BMPs), DNA methylation, and gut microbiota. Until recently the mechanisms underlying the LDD process have been elusive. Methods BMP‐related genes were extracted from the GeneCards database. The LDD transcriptome dataset was obtained from the Gene Expression Omnibus. We used linear regression and meta‐analysis to screen and integrate the differentially expressed genes associated with BMPs in LDD. Genome‐wide association studies (GWASs) of LDD were from FinnGen and UKBB. The expression quantitative trait loci (eQTLs) and DNA methylation quantitative trait loci from the blood were identified via the summary data‐based Mendelian randomization (SMR) method, and the possible blood BMP genes and their regulatory elements associated with the risk of LDD were prioritized. Intestinal eQTLs and fecal microbial QTLs (mbQTLs) were integrated, and the potential interactions between BMP gene expression in host intestinal tissue and the gut microbiota were revealed through SMR and colocalization analysis. The GWAS catalog (GCST90246169) was used to validate SMR results. Results A meta‐analysis of five datasets revealed that 113 BMP genes were differentially expressed between LDD and control tissues. Seven genes were selected as candidate pathogenic genes of LDD via the three‐step SMR method: CREB1, BMP6, PTCH1, GLI1, MEG3, GALNS, and NF1. SMR analysis also revealed five possible gut genes: HFE, MET, MAPK3, NPC1, and GDF5. The correlation between the gut microbiota and BMP gene expression in intestinal tissues was verified by eQTL‐mbQTL colocalization. Conclusion This multi‐omics study revealed that the BMP genes associated with LDD are regulated by DNA methylation. There are genetic differences between gut gene expression and the gut microbiota. These findings provide evidence for new therapeutic targets in the future.

Abstract Purpose The relationship between delayed ambulation (DA) and postoperative adverse events (AEs) following transforaminal lumbar interbody fusion (TLIF) in elderly patients remains elusive. The aim of our study was to evaluate the effects of DA on the postoperative AEs including complications, readmission and prolonged length of hospital stay (LOS). Methods This was a retrospective analysis of a prospectively established database of elderly patients (aged 65 years and older) who underwent TLIF surgery. The early ambulation (EA) group was defined as patients ambulated within 48 h after surgery, whereas the delayed ambulation (DA) group was patients ambulated at a minimum of 48 h postoperatively. The DA patients were 1:1 propensity-score matched to the EA patients based on age, gender and the number of fused segments. Univariate analysis was used to compare postoperative outcomes between the two groups, and multivariate logistic regression analysis was used to identify risk factors for adverse events and DA. Results After excluding 125 patients for various reasons, 1025 patients (≤ 48 h: N = 659 and > 48 h: N = 366) were included in the final analysis. After propensity score matching, there were 326 matched patients in each group. There were no significant differences in the baseline data and the surgery-related variables between the two groups (p > 0.05). The patients in the DA group had a significant higher incidence of postoperative AEs (46.0% vs. 34.0%, p = 0.002) and longer LOS (p = 0.001). Multivariate logistic regression identified that age, operative time, diabetes, and DA were independently associated with postoperative AEs, whereas greater age, higher international normalized ratio, and intraoperative estimated blood loss were identified as independent risk factors for DA. Conclusions Delayed ambulation was an independent risk factor for postoperative AEs after TLIF in elderly patients. Older age, increased intraoperative blood loss and worse coagulation function were associated with delayed ambulation.

Background: Recent research highlights the importance of muscular strength as a key factor in physical fitness, a strong indicator of overall mortality risk, and a vital target for preventing chronic diseases. This study used a proteome-wide Mendelian randomization analysis plus colocalization analysis for low hand grip strength to explore potential therapeutic targets for muscle weakness. Methods: We conducted two two-sample Mendelian randomization analyses from four cohorts to identify and validate the causal relationship between plasma proteins and low grip strength. We also employed bidirectional Mendelian randomization analysis with Steiger filtering, Bayesian co-localization, and phenotype scanning to detect reverse causality, thereby consolidating our Mendelian randomization findings. Downstream analyses were also undertaken of identified proteins, including knockout models, enrichment analyses, and protein-protein interaction networks. Finally, we assessed the druggability of the identified proteins. Results: At Bonferroni significance (P

Abstract Background The burden of lumbar degenerative diseases (LDD) has increased substantially with the unprecedented aging population. Identifying elderly patients with high risk of postoperative adverse events (AEs) and establishing individualized perioperative management is critical to mitigate added costs and optimize cost-effectiveness to the healthcare system. We aimed to develop a predictive tool for AEs in elderly patients with transforaminal lumbar interbody fusion (TLIF), utilizing multivariate logistic regression, single classification and regression tree (hereafter, “classification tree”), and random forest machine learning algorithms. Methods This study was a retrospective review of a prospective Geriatric Lumbar Disease Database (age ≥ 65). Our outcome measure was postoperative AEs, including prolonged hospital stays, postoperative complications, readmission, and reoperation within 90 days. Patients were grouped as either having at least one adverse event (AEs group) or not (No-AEs group). Three models for predicting postoperative AEs were developed using training dataset and internal validation using testing dataset. Finally, online tool was developed to assess its validity in the clinical setting (external validation). Results The development set included 1025 patients (mean [SD] age, 72.8 [5.6] years; 632 [61.7%] female), and the external validation set included 175 patients (73.2 [5.9] years; 97 [55.4%] female). The predictive ability of our three models was comparable, with no significant differences in AUC (0.73 vs. 0.72 vs. 0.70, respectively). The logistic regression model had a higher net benefit for clinical intervention than the other models. A nomogram based on logistic regression was developed, and the C-index of external validation for AEs was 0.69 (95% CI 0.65–0.76). Conclusion The predictive ability of our three models was comparable. Logistic regression model had a higher net benefit for clinical intervention than the other models. Our nomogram and online tool ( https://xuanwumodel.shinyapps.io/Model_for_AEs/ ) could inform physicians about elderly patients with a high risk of AEs within the 90 days after TLIF surgery.

Objective Compensation characteristics of spinal sagittal malalignment according to pelvic incidence (PI) have yet to be elucidated. This study aimed to investigate the difference in compensatory segments according to PI in elderly patients with degenerative lumbar spinal stenosis (DLSS). Methods This retrospective study included 196 patients (143 females, 53 males) suffering from DLSS with an average age of 66.73 years in our department. Sagittal parameters were obtained on the whole spinal lateral radiograph, including T1‐T12 slope (T1S‐T12S), Cobb angle (CA) of the functional units of the thoracic spine, thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), PI, the ratio of PT to PI (PT/PI), PI minus LL mismatch (PI‐LL), sagittal vertical axis (SVA). Patients were divided into the low and high PI groups according to the median value of PI. With reference to the value of SVA and PI‐LL, each PI group was further grouped into the balance subgroup (SVA 10°), and imbalance subgroup (SVA ≥50 mm). Independent samples t‐test/Mann–Whitney U test, one‐way ANOVA/Kruskal‐Wallis test, and Person correlation analysis were utilized for statistical test. Results The median value of PI was 47.65°. 96 and 100 patients were assigned to low and high PI groups, respectively. Correlation analysis indicated that the T8‐T12 slope and T10‐T12 slope were associated with PI‐LL in the high and low PI groups, respectively (all, p

Abstract Background Bacterial microbiome as a putative trigger of inflammation might indicate the cascade of mouth-gut-disc axis for causing intervertebral disc (IVD) structural failures (such as IVD degeneration and endplate change) processed. However, direct evidence for the mouth-gut-disc axis still unclear. Therefore, it is interesting to explore periodontal inflammation related to IVD structural failures and clinical outcomes. Methods This prospective cohort study enrolled older adults (aged ≥ 75 years) who scheduled to undergo elective open lumbar spine surgery. Demographic, radiological, clinical, and periodontal parameters were recorded. Independent samples t-test and Pearson’s correlation analysis were calculated. Results A total of 141 patients with lumbar degenerative disorders (56 males and 85 females; age 79.73 ± 3.34 years) were divided into edentulous group (19 patients), No/Mild group (84 patients), and Moderate/Severe group (38 patients). The incidence rates of IVD degeneration in each lumbar segmental level based on Pfirrmann grade and endplate change in the fourth and fifth lumbar vertebrae, and Visual Analogue Scale (VAS) low back pain (LBP) and leg pain of patients at preoperative in dentate group was significantly higher compared with edentulous group, especially the comparisons between Moderate/Severe and edentulous groups. There were no significant differences in the range of motion, lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope, and disc height between dentate and edentulous groups. There was a positive association between plaque index (PLI) and pain scores (VAS LBP: r = 0.215, P = 0.030 and VAS leg pain: r = 0.309, P = 0.005), but no significant difference in Oswestry disability index (ODI) score. Conclusion Results show that the severity of periodontitis is associated with higher incidence rates of IVD degeneration and endplate change and clinical outcomes in older adults with lumbar degenerative disorders. Furthermore, the discovery of these relationships unveils a novel mechanism through which the alterations in oral microbiome composition potentially promote IVD degeneration and pain.

Abstract Objective The aim of this study was to investigate the association between spinal alignment and preoperative patient-reported outcomes (PROs) in patients with degenerative lumbar spondylolisthesis (DLS) and to identify the independent risk factors for worse preoperative PROs. Methods In total, 101 patients suffering from DLS were retrospectively studied within a single medical center. Age, sex, height, weight, and body mass index were uniformly recorded. PRO-related indicators include the Oswestry Disability Index (ODI), the Japanese Orthopedic Association’s (JOA) score, and the visual analog scale (VAS) for back and leg pain. Sagittal alignment, coronal balance, and stability of the L4/5 level were evaluated through whole-spine anteroposterior and lateral radiographs and dynamic lumbar X-ray. Results Increasing age (P = 0.005), higher sagittal vertical axis (SVA) (P

Abstract Objective Cervical sagittal alignment changes (CSACs) influence outcomes and health-related quality-of-life. Anterior cervical discectomy and fusion (ACDF), laminectomy with fusion (LCF), and laminoplasty (LP) are common treatments for multisegmental cervical spondylotic myelopathy; however, these approaches need to be compared. Methods Our study included 167 patients who underwent ACDF, LCF, or LP. Patients were divided into four groups according to C2-C7 Cobb angle (CL): kyphosis (CL

Abstract Objective To generate a compensatory classification to evaluate sagittal spinal malalignment with lumbar degeneration. Methods We included 162 patients with low back pain who underwent full-length spinal radiography in our hospital from August 2019 to October 2021. Using full-length spine X-rays, we measured pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), thoracic kyphosis (TK), lumbar lordosis (LL), C7 slope (C7S), thoracolumbar kyphosis (TLK), and C7 sagittal vertical axis (SVA). We also recorded the Oswestry Disability Index (ODI) and visual analog scale (VAS). Patients were divided into four groups based on the SRS-Schwab classification and four other groups based on the compensatory classification. Results ODI correlated with age, SS, LL, TK, C7-SVA, SRS-Schwab classification, and compensatory classification. Lumbar VAS score correlated with LL, TK, C7-SVA, SRS-Schwab classification, and compensatory classification. Leg VAS score only correlated with LL. Hidden imbalance and imbalance with compensation had more significant PT and larger TK than balance patients. The symptoms of the four compensatory classification groups gradually worsened. Conclusion The spinal-pelvic sagittal balance in patients with lumbar degeneration based on pelvic and thoracic compensation can reflect spinal balance and symptoms. This parameter might help evaluate spine sagittal alignment in elderly patients with lumbar degeneration.

Abstract Purpose To investigate the effect of interlaminar Coflex stabilization (ICS) at various segments in the topping-off procedure on local and global spinal sagittal alignment. Methods Eighty-nine consecutive patients with degenerative lumbar spinal stenosis (DLSS) who underwent ICS and transforaminal lumbar interbody fusion (TLIF) were retrospectively reviewed. They were divided into Group A (L4-L5 ICS + L5-S1 TLIF), Group B (L3-L4 ICS + L4-S1 TLIF), and Group C (L2-L3 ICS + L3-S1 TLIF) according to their fusion levels. The measured local sagittal parameters included the implanted segmental angle (ISA), intervertebral disc angle (IDA), intervertebral foreman height (IFH), and disc height. The assessed global sagittal parameters included thoracic kyphosis, lumbar lordosis (LL), the fused segment angle (FSA), the sacral slope, the pelvic tilt, pelvic incidence, and the sagittal vertical axis. The Oswestry Disability Index (ODI) and visual analog scales (VAS) were recorded to evaluate the clinical outcomes. Results Regarding the local alignment parameters, the ISA and IDA decreased immediately after surgery in Groups A and B, followed by an increase at the last follow-up (all, P

Abstract Purpose This retrospective cross-sectional study investigated variations in the ratio of cervical lordosis to C7 slope (CL/C7S) at different stages of global sagittal balance to better understand how global sagittal alignment affects cervical alignment. Methods A total of 255 patients with the degenerative lumbar disease were retrospectively studied within a single medical center. Whole spine radiographs were used to evaluate sagittal parameters, mainly including occiput-C2 lordosis (OC2), cervical lordosis (CL), C7 slope (C7S), the ratio of cervical lordosis to C7 slope (CL/C7S), cervical sagittal vertical axis (CSVA), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic tilt (PT), pelvic incidence (PI), PI minus LL mismatch (PI–LL), and sagittal vertical axis (SVA). Patients were divided into the balance group (SVA 10°), and imbalance group (SVA > 50 mm). Results Significant correlations were found between CL/C7S and OC2 (r = − 0.334), CSVA (r = − 0.504), PI–LL (r = 0.189), and SVA (r = 0.309). Multivariable linear regression analysis indicated that patients in the hidden imbalance group had lower CL/C7S than those in the balance group (B = − 0.234, P

Abstract Purpose The prevalence of degenerative spinal deformity (DSD) and the increased cost of correction surgery impose substantial burdens on the health care and insurance system. The aim of our study was to investigate the effects of the implementation of Enhanced Recovery After Surgery (ERAS) protocol on postoperative outcomes after complex spinal surgery. Methods A retrospective analysis of prospectively established database of DSD was performed. The consecutive patients who underwent open correction surgery for degenerative spinal deformity between August 2016 and February 2022 were reviewed. We extracted demographic data, preoperative radiographic parameters, and surgery-related variables. The ERAS patients were 1:1 propensity-score matched to a historical cohort by the same surgical team based on age, gender, BMI, and number of levels fused. We then compared the length of hospital stay (LOS), physiological functional recovery, and the rates of complications and readmissions within 90 days after surgery between the groups. Results There were 108 patients included, 54 patients in the ERAS cohort, and 54 patients matched control patients in the historical cohort. The historical and ERAS cohorts were not significantly different regarding demographic characteristics, comorbidities, preoperative parameters, operative time, and reoperation rate (P > 0.05). Patients in the ERAS group had significantly shorter postoperative LOS (12.0 days vs. 15.1 days, P = 0.001), average days of drain and urinary catheters placement (3.5 days vs. 4.4 days and 1.9 days vs 4.8 days, respectively), and lower 90-day readmission rate (1.8% vs. 12.9%, P = 0.027). The first day of assisted-walking and bowel movement occurred on average 1.9 days (2.5 days vs. 4.4 days, P = 0.001) and 1.7 days (1.9 days vs. 3.6 days, P = 0.001) earlier respectively in the ERAS group. Moreover, the rate of postoperative urinary retention (3.7% vs. 16.7%, P = 0.026) and surgical site infection (0% vs. 7.4%, P = 0.046) were significantly lower with ERAS protocol applied. Conclusions Our study confirmed that the ERAS protocol was safe and essential for patients undergoing thoracolumbar deformity surgery for DSD. The ERAS protocol was associated with a shorter postoperative LOS, a lower rate of 90-day readmission, less rehabilitation discharge, and less postoperative complications.

Abstract Objective To analyze the correlation between the changes in cervical curvature and the sagittal parameters of spino-pelvic and clinical efficacy after posterior laminoplasty (LP). Methods The patients with cervical spondylosis treated with LP from June 2018 to December 2020 were reviewed. The preoperative and follow-up spine full-length films were measured. The measured data included C2–C7 Cobb angle, C2–7 sagittal vertical axis (SVA), T1 slope (T1S), pelvic incidence, sacral slope (SS), pelvic tilt (PT), lumbar lordosis (LL), thoracic kyphosis (TK), and C7-SVA. Japanese Orthopaedic Association (JOA) score and neck disability index (NDI) score were recorded before surgery and follow-up. Results There were 56 patients in this study. There were no significant differences in spino-pelvic sagittal parameters before and after surgery; however, the JOA score significantly improved. The changes in postoperative cervical lordosis correlated with SS, PT, LL, T1S, and C7-SVA (P

Abstract Study design Retrospective case–control study. Objectives Proximal junctional kyphosis (PJK) is a postoperative complication involving the proximal segments which is commonly seen in patients with degenerative spine diseases (DSD). The purpose of the present study was to identify predictive factors for postoperative PJK in elderly patients with DSD. Methods We reviewed elderly patients with DSD who underwent thoracolumbar fusion involving no less than 3 levels. Patients who developed PJK were propensity score-matched with patients with DSD who received the same procedure but did not develop PJK. Demographic characteristics, sagittal vertical axis (SVA), computed tomography (CT) value (Hounsfield unit), and paraspinal muscle parameters were compared between PJK and non-PJK groups. Results Eighty-three PJK and non-PJK patients were selected by propensity score matching for age, sex, history of smoking, body mass index, number of fused segments, and upper instrumented vertebra (UIV) location. SVA showed no significant difference between the two groups. In PJK group, fatty infiltration (FI) in erector spinae and multifidus was significantly greater, while the relative cross-sectional area (rCSA) of erector spinae was significantly smaller than that in non-PJK group. CT value was significantly lower in PJK group. Lower erector spinae rCSA and CT value of the UIV, higher erector spinae FI and multifidus FI were identified as predictors of postoperative PJK. Conclusions PJK is a common complication in older patients with DSD. Paraspinal muscle degeneration and low bone mineral density of the UIV are predictors of PJK. Protective measures targeting paraspinal muscles and the UIV may help prevent postoperative PJK.

Background: Disc height (DH) change is considered one of the most critical factors in assessing intervertebral disc degeneration (IVD). Pfirrmann et al. developed a scoring system for disc degeneration evaluation based on changes in DH in magnetic resonance imaging (MRI). While the relationship between DH measurements and Pfirrmann scores for disc degeneration has been explored, the validity of different DH measuring techniques or their connection with disc degeneration is yet uncertain. The present study investigates intra-rater and inter-rater agreement and reliability of different DH measurement methods on MRI and evaluates the relationship between different DH measurement methods and Pfirrmann scores of IVD degeneration, as well as between different Pfirrmann scores and clinical outcomes. Methods: Adult patients with MRI scans of the lumbar spine were recruited. Eight DH measuring techniques were tested for intra-rater and inter-rater agreement and reliability. Bland and Altman's Limits of Agreement (LOA) was used to evaluate intra-rater and inter-rater agreements. Intra-rater and inter-rater reliability were evaluated using intra-class correlations (ICC) with 95 % confidence intervals (95 % CI). The association between DH and Pfirrmann scores was examined using one-way ANOVA. Results: Excellent intra-rater reliability was reported for 332 participants on DH (ranging from 0.912 (0.901, 0.923) to 0.973 (0.964, 0.981) and from 0.902 (0.892, 0.915) to 0.975 (0.962, 0.985) by two independent raters). All measuring methods had high intra-rater agreement, except for methods 4 and 5. All methods had good-to-excellent of inter-rater reliability on DH (ICCs ranging from 0.812 (0.795, 0.828) to 0.995 (0.994, 0.995)) except for the posterior disc material length of method 5 (ICC 0.740 (0.718, 0.761)). Methods 1 to 6 for evaluating DH in patients with spondylolisthesis had poor inter-rater reliability. The IVD levels with grades IV and V in Pfirrmann scores had significantly lower DH than the IVD levels with grades I to III in Pfirrmann scores. IVD levels with grades IV and V in Pfirrmann scores had significantly higher VAS and ODI than IVD levels with grades I in Pfirrmann scores. Conclusion: A good-to-excellent intra-rater and inter-rater reliability was achieved on most DH measuring methods on MRI following a standardized and structured protocol. However, small anatomical structures and different tissue borders could influence measurements. Additionally, DH can differentiate between grade IV and V Pfirrmann scores, and severe IVD degeneration (IV and V Pfirrmann) is linked to clinical outcomes.

Abstract Study design Retrospective cohort study. Purpose The aim of our study was to determine the rates and indications of reoperations following primary lumbar fusion, as well as the independent risk factors for early and late reoperation. Methods We retrospectively reviewed patients who underwent lumbar fusion surgery between January 2017 and March 2020. All patients were followed up for more than 2 years. Characteristics, laboratory tests, primary diagnosis and surgery-related variables were compared among the early reoperation ( 3 months) and the non-reoperation groups. Multivariable logistic regression analysis was used to identify independent risk factors for early and late reoperations. Results Of 821 patients included in our studies, 34 patients underwent early reoperation, and 36 patients underwent late reoperation. The cumulative reoperation rate was about 4.1% (95% CI 3.8–4.5%) at 3 months, 6.2% (95% CI 5.9–6.5%) at 1 year and 8.2% (95% CI 8.0–8.5%) at 3 years. Multivariable analysis indicated that osteoporosis (odds ratio [OR] 3.6, 95% CI 1.2–10.5, p = 0.02) and diabetes (OR 2.1, 95% CI 1.1–4.5, p = 0.04) were independently associated with early reoperation and multilevel fusion (OR 2.4, 95% CI 1.1–5.4, p = 0.03) was independently associated with late reoperation. Conclusions The most common reasons for early reoperation and late operation were surgical site infection and adjacent segment diseases, respectively. Osteoporosis and diabetes were independent risk factors for early reoperation, and multilevel fusion was independent risk factor for late reoperation. Surgeons should pay more attention to these patients, and future studies should consider the effects of follow-up periods on results.

Abstract Background Measurement of T1 slope (T1S) can be difficult due to the anatomical positioning of the shoulders. And thoracic inlet angle (TIA) was a morphological parameter and not changed by the position. We proposed a new parameter, TIA minus C0-7 angle (TIA-C07), to evaluate C2-7 SVA in order to overcome the T1S imperfection. Methods This was a retrospective radiological analysis of symptomatic subjects. The following cervical parameters were measured: Cervical lordosis angle (CL), C0-7 angle (C0-7), occiput-C2 lordosis angle (O-C2), C2-7 sagittal vertical axis (C2–7 SVA), TIA and TIA-C07. The Pearson correlation test was calculated, and the stepwise multiple regression analysis was conducted to determine the best predictor for C2-7 SVA. A paired sample t test was used to compare the predicted and measured C2-7 SVA. Results The mean age of 113 patients was 60.02 ± 9.67. The average O-C2, CL, C0-7, TIA, TIA-C07 and C2-C7 SVA was 29.24 ± 8.48°, 13.67 ± 11.22°, 42.91 ± 11.44°, 76.07 ± 9.54°, 33.16 ± 13.18° and 21.34 ± 11.42 mm. The predictive formula was founded: C2-7 SVA = 2.80 + 0.56 * (TIA—C07) (R = 0.645, R2 = 0.416). There was no statistical difference between the predicted and the measured C2-7 SVA (t = 0.085, P = 0.933). Conclusions TIA and C0-7 mismatch may significantly impact cervical alignment, and a greater T1A-C07 was related to a greater degree of C2-7 SVA. TIA-C07 may be a more important predictor for C2-7 SVA.

Abstract Background The compensatory mechanisms for cervical lordosis change after laminectomy with fusion was not clear. The objective of this study was to evaluate the compensatory behaviors for cervical lordosis change after laminectomy with fusion. Methods This was a retrospective radiological analysis of 43 patients with cervical spondylotic myelopathy who underwent laminectomy with fusion (LCF). The following cervical parameters were measured: C2-7 Cobb angle (C2-7), occiput-C2 angle (O-C2), the cervical sagittal vertical axis (cSVA), and T1 slope (T1S). The difference was calculated for all angle parameters between the two time points using the following formula: the amount of change (Δ) = (value at the follow-up)—(preoperative value). Non-parametric tests and the t-test were used to compare the difference. The Pearson correlation test was performed, and stepwise multiple regression analysis was performed to determine the best correlation between ∆cSVA and ∆T1S. Results The mean age of 43 patients was 65.51 ± 9.80 years. All patients were classified into two subgroups based on ΔcSVA: Group M (maintained) and, Group I (increased). The preoperative O-C2, C2-7, T1S, and cSVA were similar between Group M and group I (p = 0.950, p = 0.731, p = 0.372, and p = 0.152, respectively). Postoperative O-C2 and postoperative cSVA were significantly different (p = 0.036 and p = 0.004, respectively). ∆O-C2, ∆T1S and ∆cSVA were significantly different between the two groups (p = 0.006, p = 0.000, and p = 0.000, respectively). ΔcSVA had significant correlations with ΔO-C2 neutral angle (r = 0.377) and ΔT1S (r = 0.582). A linear regression equation was established: ΔcSVA = 0.602 + 0.103 * ΔT1S (R = 0.582, R2 = 0.339). Conclusions The decrease of TIS should be the first and foremost compensation for the loss of lordosis in C2-7 segments after LCF. When the change of T1S alone can not prevent the deterioration of cervical sagittal balance, further increases in the O-C2 segment occur.

PurposeTo investigate the influence of changes in T1 slope (T1S) and cervical sagittal vertical axis (CSVA) on cervical laminoplasty outcomes.MethodsEighty-one patients with cervical spondylotic myelopathy (CSM) treated with cervical laminoplasty were enrolled in this study. Demographic parameters included age and follow-up time. Imaging data included occiput-C2 lordosis (OC2), C2–C7 Cobb angle (CL), T1S, CSVA. Outcome assessment indicators included the Japanese Orthopedic Association (JOA) score, JOA recovery rate, and neck disability index (NDI). All patients were grouped based on preoperative T1S and variation in CL after surgery, respectively. Patients with decreased CL postoperatively were further grouped according to whether they were combined with T1S reduction.ResultsThere were no significant differences in the final JOA score, JOA recovery rate, or NDI between patients with different T1S. Patients with loss of CL postoperatively had lower JOA score and JOA recovery rate, but higher NDI than patients with sustained CL. Furthermore, patients with CL loss but compensate for it with reduction in T1S had lower CSVA, higher JOA score and JOA recovery rate than those with CL loss alone.ConclusionsDecreased T1S postoperatively prevents the tendency of the cervical spine to tilt forward by regulating CSVA and facilitates recovery of neurological function after cervical laminoplasty.

BackgroundThe rate and volume of lumbar spinal fusion (LSF) surgery performed for patients aged 75 years and older increased in recent years. The purposes of our study were to identify factors associated with postoperative dissatisfaction and evaluate the predictive value of comprehensive geriatric assessment (CGA) for dissatisfaction at 2 years after elective short-segment (one- or two- level) LSF in patients aged 75 and older.MethodsThis was a retrospective study using a prospectively collected database of consecutive patients (aged 75 and older) who underwent elective short-segment transforaminal lumbar interbody fusion surgery for degenerative diseases from June 2018 to May 2020. Preoperative CGA consisting six domains was performed for each patient 1 day before the operative day. Univariate and multivariate analyses were performed to identify factors that predict for dissatisfaction with surgical treatment. The primary outcome was patient satisfaction with LSF surgery, as measured by the North American Spine Society (NASS) satisfaction scale. Secondary outcomes included postoperative complications, the length of stay, visual analog scale (VAS), and Oswestry Disability Index.ResultsA total of 211 patients were available for a follow-up at 2 years and included in our final study cohort with a mean age of 80.0 years. A total of 175 patients (82.9%) were included in the satisfied group, and 36 patients (17.1%) were included in the not dissatisfied group. In the dissatisfied group, there was a higher incidence of postoperative complications (30.6% vs. 14.3%, p = 0.024) and greater VAS scores for lower back (4.3 ± 1.9 vs. 1.3 ± 1.4, p = 0.001) and leg (3.9 ± 2.1 vs. 0.9 ± 1.3, p = 0.001). Multivariate regression analysis revealed that patients with greater CCI score [odd ratio (OR) 2.56, 95% CI, 1.12–5.76; p = 0.030 for CCI 1 or 2 and OR 6.20, 95% CI, 1.20–28.69; p = 0.024], and depression (OR 3.34, 95% CI, 1.26–9.20; p = 0.016) were more likely to be dissatisfied compared with patients with the CCI score of 0 and without depression.ConclusionsSatisfaction after LSF in older patients (aged 75 and older) was similar to that of previously reported younger patients. Preoperative depression and higher CCI scores were independent risk factors for postoperative dissatisfaction two years after LSF surgery. These results help inform decision-making when considering LSF surgery for patients aged 75 and older.

ObjectiveCervical sagittal parameters have been widely used to predict clinical outcomes in patients with cervical spondylotic myelopathy (CSM). This study aims to coin a novel cervical sagittal parameter defined as the ratio of cervical sagittal vertical axis to T1 slope (CSVA/T1S) and to investigate the correlation between CSVA/T1S and postoperative HRQOL after laminoplasty.MethodsA total of 102 CSM patients treated with cervical laminoplasty from our database were retrospectively reviewed. All patients were followed up for >12 months. Radiological parameters were measured using lateral cervical radiographs, including occiput-C2 lordosis (OC2), cervical lordosis (CL), CSVA, and T1S. Clinical parameters included the Japanese Orthopedic Association (JOA) score, neck disability index (NDI), and JOA recovery rate. Patients were grouped by preoperative T1S, T1S-CL, and CSVA/T1S value, respectively. Clinical and radiological outcomes were compared between the groups.ResultsPatients with high CSVA/T1S had greater OC2 and CSVA but lower CL than those in the low CSVA/T1S group pre-and postoperatively. With respect to HRQOL results, the final NDI was 12.46 ± 9.11% in the low CSVA/T1S group, which was significantly lower than that in the high CSVA/T1S group (17.68 ± 8.81%, P = 0.040). Moreover, only CSVA/T1S was detected to be significantly correlated with final NDI (r = 0.310, P = 0.027). No significant correlation was found between clinical results and other cervical sagittal parameters, including T1S, CSVA, and T1S-CL.ConclusionsPreoperative CSVA/T1S was correlated with postoperative NDI in patients with CSM after cervical laminoplasty. Patients with low preoperative CSVA/T1S achieved better neurological function improvement after cervical laminoplasty. Cervical laminoplasty could be an appropriate choice for patients with lower preoperative CSVA/T1S.

Abstract Background Enhanced recovery after surgery (ERAS) program is an evidence-based improvement over non-ERAS traditional care. The aim of the present study was to analyze the safety, feasibility, and efficacy of an ERAS program in patients over 70 years undergoing lumbar arthrodesis by comparison with non-ERAS traditional care. Methods During January 2018 to December 2018, patients enrolled received non-ERAS traditional care, while the ERAS program was implemented from January to December 2019. Demographic characteristics, comorbidities, surgical data and postoperative recovery parameters were collected from all patients. Postoperative pain scores were evaluated by visual analog scales (VAS). The clinical outcomes were length of stay (LOS), postoperative complications and postoperative pain scores. Compliance results were also collected. Result A total of 127 patients were enrolled, including 67 patients in the non-ERAS traditional care group and 60 patients in the ERAS group. The demographic characteristics and comorbidities of the two groups showed no significant differences. The LOS of patients treated with ERAS program (13.6 ± 4.0 days) was significantly less than that of patients treated with non-ERAS traditional care (15.6 ± 3.9 days) (p = 0.034). Complication rate was 8.3% in the ERAS group versus 20.9% in the non-ERAS traditional care group (p = 0.048). VAS (back) in the ERAS group was significantly lower on postoperative day (POD) 1 and POD2. Postoperative recovery parameters were improved in the ERAS group. The overall compliance with the ERAS program was 94%. Conclusions Based on our results, ERAS program is safer and more effective for elderly patients over 70 undergoing lumbar arthrodesis than non-ERAS traditional care.

Abstract Background There were several reports describing the biomechanics and microstructure of multifidus muscles in patients with lumbar disc herniation. However, correlations between lumbar multifidus muscle atrophy (LMA), spinopelvic parameters, and severity of adult degenerative scoliosis (ADS) have not been investigated. The study evaluated the impact of LMA and spinopelvic parameters on the severity of ADS. Methods One hundred and thirty-two patients with ADS were retrospectively reviewed. Standing whole-spine X-ray was used to evaluate the coronal (coronal Cobb angle, CA; coronal vertical axis, CVA) and sagittal (sagittal vertical axis, SVA; thoracic kyphosis, TK; lumbar lordosis, LL; pelvic incidence, PI; pelvic tilt, PT; sacral slope, SS) parameters. LMA was evaluated on axial T2-weighted magnetic resonance imaging (MRI) at intervertebral levels above and below the vertebra at the apex of the scoliotic curve. Clinical symptoms were evaluated by the Oswestry Disability Index (ODI) and the Japanese Orthopaedic Association (JOA) score. Multiple linear regression was used to assess correlations between LMA, spinopelvic parameters, and severity of scoliosis. Results LL and PT were negatively correlated with CA (P

Background: Frailty is recognized as a surrogate for physiological age and has been established as a valid and independent predictor of postoperative morbidity, mortality, and complications. Enhanced recovery after surgery (ERAS) can enhance surgical safety by minimizing stress responses in frail patients, enabling surgeons to discharge patients earlier. However, the question of whether and to what extent the frailty impacts the post-ERAS outcomes in older patients remains. Materials and methods: An evidence-based ERAS program was implemented in our center from January 2019. This is a prospective cohort study of patients aged =75 years who underwent open transforaminal lumbar interbody fusion (TLIF) for degenerative spine disease from April 2019 to October 2021. Frailty was assessed with the Fried frailty scale (FP scale), and patients were categorized as non/prefrail (FP 0-2) or frail (FP = 3). The preoperative variables, operative data, postoperative outcomes, and follow-up information were compared between the two groups. Univariate and multivariate logistic regression analyses were used to identify risk factors for 90-day major complications and prolonged length of hospital stay after surgery. Results: A total of 245 patients (age of 79.8 ± 3.4 year) who had a preoperative FP score recorded and underwent scheduled TLIF surgery were included in the final analysis. Comparisons between nonfrail and prefrail/frail patients revealed no significant difference in age, sex, and surgery-related variables. Even after adjusting for multiple comparisons, the association between Fried frailty and ADL-dependency, IADL-dependency, and malnutrition remained significant. Preoperative frailty was associated with increased rates of postoperative adverse events. A higher CCI grade was an independent predictor for 90-day major complications, while Fried frailty and MNA-SF scores <12 were predictive of poor postoperative recovery. Conclusion: Frail older patients had more adverse post-ERAS outcomes after TLIF compared to non/prefrail older patients. Continued research and multidisciplinary collaboration will be essential to refine and optimize protocols for surgical care in frail older adults. [ABSTRACT FROM AUTHOR]

This work examines the linear instability of a viscoelastic confined liquid jet as the acoustic oscillations are taken into consideration, which is expressed as the oscillatory gas velocity, and this theoretical problem is solved using the Floquet theory. The unstable regions are dominated by capillary instability, Kelvin–Helmholtz instability (KHI), and parametric instability, and the impact of heat and mass transfer in the different unstable regions is also discussed. In addition, the different instability mechanism for different azimuthal wavenumbers is found. Because of its viscoelasticity, the liquid jet is more unstable than its Newtonian counterpart. In addition, the influence of the constant time ratio, Reynolds number, and elasticity number is more dramatic on the parametric instability than that on the KHI. The forcing frequency impacts the parametric instability mainly by changing corresponding wavenumber of parametric unstable region. Furthermore, a novel phenomenon is that heat and mass transfer has a complex effect on KHI and parametric instability, depending on the increase extent of aerodynamic force induced by mass transfer. For a smaller density ratio between gas and liquid, heat and mass transfer enhances KHI and parametric instability. Moreover, the increase in the density ratio and Weber number can enhance the interfacial instability and expands the unstable wavenumber range. [ABSTRACT FROM AUTHOR]

This work examined the linear instability of a two-dimensional liquid film on an oscillating plane theoretically in the presence of a static electric field perpendicular to the plane. The liquid was considered to be viscous and perfectly conducting, while the gas was considered to be viscous and dielectric. The viscous potential theory and Floquet theory were adopted to obtain the dispersion equation. The influences of electric field intensity, forcing amplitude, forcing frequency, and viscosity were obtained. The results showed that with there is more than one instability region with a non-zero forcing amplitude. The first instability region is called inherent instability, which is due to the electric force overcoming the viscous dissipation, surface tension, and gravity, while the other regions are due to the parametric instability induced by the oscillating plane, forming famous Faraday waves. It was found that increasing the forcing amplitude stabilizes the inherent instability but has a destabilizing impact on Faraday waves. In addition, the increase in the electric field intensity and forcing frequency enhances the inherent instability but has a complex impact on the Faraday waves, depending on the intensity of the viscous dissipation, which is approximately proportional to the square of the wavenumber. [ABSTRACT FROM AUTHOR]

In this work, we have prepared a novel yttria‐stabilized zirconia fiber (YSZf)‐reinforced (La1/5Nd1/5Sm1/5Gd1/5Yb1/5)2Zr2O7 porous ceramics (YSZf/(5RE1/5)2Zr2O7 PCs) through a foam‐gelcasting‐freeze drying process. The microstructure, phase composition, density, porosity, thermal conductivity, and compressive strength of the as‐prepared YSZf/(5RE1/5)2Zr2O7 PCs were systematically investigated. In addition, the high‐temperature thermal cycle stability and thermally insulating property of the samples were also tested. The results indicated that the as‐synthesized YSZf/(5RE1/5)2Zr2O7 PCs (with 25 wt% YSZ fibers) exhibited high porosity, high compressive strength, low thermal conductivity as well as low thermal cycling shrinkage. This work demonstrated that the added YSZ fiber can remarkably improve the strength of (5RE1/5)2Zr2O7 PCs with the high porosity, and as‐developed YSZf/(5RE1/5)2Zr2O7 PCs would be an excellent candidate for high‐temperature thermal insulator materials. [ABSTRACT FROM AUTHOR]