Ligamentum flavum hypertrophy (HLF) is the most important component of lumbar spinal canal stenosis (LSCS). Analysis of hypertrophied ligamentum flavum (HLF) samples from patients with LSCS can be an important que. The current study analyzed the surgical samples of HLF samples in patients with LCSC using quantitative and qualitative high performance-liquid chromatography and mass spectrometry. We collected ligamentum flavum (LF) tissue from twelve patients with LSCS and from four patients with lumbar disk herniation (LDH). We defined LF from LSCS patients as HLF and that from LDH patients as non-hypertrophied ligamentum flavum (NHLF). Total lipids were extracted from the LF samples and evaluated for quantity and quality using liquid chromatography and mass spectrometry. The total lipid amount of the HLF group was 3.6 times higher than that of the NHLF group. Phosphatidylcholines (PCs), ceramides (Cers), O-acyl-ω-hydroxy fatty acids (OAHFAs), and triglycerides (TGs) in the HLF group were more than 32 times higher than those of the NHLF group. PC(26:0)+H+, PC(25:0)+H+, and PC(23:0)+H+ increased in all patients in the HLF group compared to the NHLF group. The thickness of the LF correlated significantly with PC(26:0)+H+ in HLF. We identified the enriched specific PCs, Cers, OAHFAs, and TGs in HLF.

Introduction Regression analysis of adult spinal deformity (ASD) databases in North America (NA) has yielded radiographic disability thresholds for sagittal vertical axis (SVA), pelvic tilt (PT), and pelvic incidence to lumbar lordosis (PI–LL), which have been used in formulating the Schwab–SRS ASD classification. These thresholds are often used as correction goals for surgery planning, but it is unclear whether these thresholds vary in other geographic regions or ethnicities. This is the first comparison of radiographic disability thresholds between NA and Asian populations of ASD. Patients and Methods Retrospective, multicenter case series of 595 operative patients with ASD with baseline radiographs and Oswestry disability index (ODI) from 11 sites across USA ( n = 402) and Japan (JPN, n = 193). Patients were compared at baseline in ODI, ODI need for improvement (ODIni, calculated from age/ethnic normative values), and radiographs. Linear regression was used to define thresholds for disability. Results Differences existed in mean age (USA 52.5 ± 22.5 years vs. JPN was 56.5 ± 15.4 years, p = 0.012) and revisions (USA 48% vs. JPN 2%, p < 0.001), but not gender (USA 85% women and JPN 80% women). At baseline, there were no differences in sagittal parameters except PI, which was significantly smaller in the JPN cohort. Linear regression revealed differences in radiographic parameters corresponding to ODI of 30 to 40. JPN had higher PI–LL and PT for ODI 30 and 40 but similar SVA thresholds. Significant differences existed in Schwab classification curve type (JPN with more double curves, p < 0.001) and PT (JPN with lower grade) but not in PI–LL modifier. JPN had a significantly lower ODI (USA 43.7 vs. JPN 36.2, p < 0.001), without a significant difference in ODIni. Conclusion At baseline, patients in both cohorts had a similar sagittal deformity but different morphology. Disability thresholds for SVA appear to be maintained across ethnicities but with differences in pelvic morphology (PI–LL and PT). The JPN cohort had significantly smaller PI and multiple coronal curves compared with the USA cohort. Despite similar sagittal malalignment, the JPN cohort had a significantly lower ODI without a significant difference in ODIni.

Study Design. Retrospective study. Objective. To determine whether an occupancy rate of a pedicle screw (ORPS) <80% in an upper instrumented vertebra (UIV) is a risk factor for UIV fracture (UIVF). Summary of Background Data. The ratio of the length of the pedicle screw to the anteroposterior diameter of the vertebral body at the UIV is defined as ORPS. Previous studies showed that the stress on the UIV is reduced to the greatest degree when ORPS is >80%. However, it remains unclear whether these results are clinically valid. Patients and Methods. A total of 297 patients who had undergone adult spinal deformity surgery were included in the study. The group with an ORPS ≥80% and <80% was defined as the H (n = 198) and L (n = 99) group, respectively. Propensity score matching and logistic regression analysis were used to evaluate the association between ORPS and the development of UIVF adjusting for confounders. Results. The mean age of both groups was 69 years. The average ORPS in the L and H groups was 70% and 85%, respectively. The incidence of UIVF was 30% in group L and 15% in group H (P < 0.01). In addition, the 99 patients in group H were subdivided into 2 groups according to whether the screws penetrated the anterior wall of the vertebral body: 68 patients had no penetration (group U), whereas 31 patients showed evidence of penetration (group B). A total of 10% and 26% of the patients in the U and B groups, respectively, experienced UIVF (P < 0.05). Logistic regression analysis indicated that ORPS <80% was significantly associated with UIVF (P = 0.007, odds ratio: 3.9, 95% CI 1.4–10.5). Conclusion. To reduce UIVF, screw length should be set with a target ORPS of 80% or higher. If the screw penetrates the anterior wall of the vertebral body, the risk of UIVF is greater.

OBJECTIVE An aberrant inflammatory response, which plays a role in the development of postoperative complications, is observed in autoimmune diseases, Yet, there is a paucity of literature regarding the effects of autoimmune diseases after adult spinal deformity (ASD) surgery. The goal of this study was to determine the effects of autoimmune diseases (rheumatoid arthritis, systemic lupus erythematosus) on postoperative medical complications, patient-reported outcome measures (PROMs), and radiographic alignment in patients who underwent ASD surgery. METHODS Propensity-score matching for age and sex was performed for patients with autoimmune disease (group A) and nonautoimmune patients (group NA1). Postoperative medical complications, preoperative and 2-year follow-up PROMs, and preoperative, immediate postoperative, and 2-year follow-up radiographic alignment were evaluated. RESULTS Among 386 patients (27 in group A and 359 in group NA1), autoimmune patients had a higher incidence of respiratory complications (11.1% vs 2.2%, p = 0.036), gastrointestinal complications (14.8% vs 3.1%, p = 0.016), urinary tract infections (14.8% vs 3.1%, p = 0.016), cholecystitis (7.4% vs 0%, p = 0.005), and fever of unknown origin (14.8% vs 0%, p < 0.001). Autoimmune patients had worse preoperative ODI (54.2 vs 44.7, p = 0.004) and 2-year follow-up Scoliosis Research Society 22-item Questionnaire (SRS-22) scores (3.1 vs 3.5, p = 0.039), with higher preoperative sacral slope (23.4° vs 17.8°, p = 0.020). Propensity-score matching for age and sex yielded 27 pairs (group A and group NA2). Having at least one medical complication (group A 74.1% vs group NA2 22.2%, p < 0.001), total complications per person (1.3 vs 0.3, p = 0.010), prognostic nutrition index (44.8 vs 48.6, p = 0.034), steroid use (51.9% vs 0%, p < 0.001), immunosuppressant use (48.1% vs 0%, p < 0.001), length of hospital stay (38 vs 27 days, p = 0.018), and discharge to care facility (29.6% vs 7.4%, p = 0.036) were higher in group A. Preoperative ODI (54.2 vs 43.2, p = 0.011) and 2-year follow-up SRS-22 scores (3.1 vs 3.6 p = 0.019) were worse in group A. No differences were observed in radiographic alignment. CONCLUSIONS Patients with autoimmune disease had higher complication rates and worse PROMs following ASD surgery in this study. There was no difference in spinal alignment compared with controls. Multidisciplinary planning and full disclosure of possible adverse effects should be completed prior to correction of ASD in patients with autoimmune disease.

Introduction:The number of patients on antithrombotic drugs for coronary heart disease or cerebrovascular disease has been increasing with the aging of society. We occasionally need to decide whether to continue or discontinue antithrombotic drugs before spine surgery. The purpose of this study is to understand the current perioperative management of antithrombotic drugs before elective spine surgery in Japan. Methods:In 2021, members of the Japanese Society for Spine Surgery and Related Research (JSSR) were asked to complete a web-based questionnaire survey that included items concerning the respondents' surgical experience, their policy regarding discontinuation or continuation of antithrombotic drugs, their reasons for decisions concerning the management of antithrombotic drugs, and their experience of perioperative complications related to the continuation or discontinuation of these drugs.Results: A total of 1,181 spine surgeons returned completed questionnaires, giving a response rate of 32.0%. JSSR board-certified spine surgeons comprised 75.1% of the respondents.Depending on the management policy regarding antithrombotic drugs for each comorbidity, approximately 73% of respondents discontinued these drugs before elective spine surgery, and about 80% also discontinued anticoagulants. Only 4%-5% of respondents reported continuing antiplatelet drugs, and 2.5% reported continuing anticoagulants. Among the respondents who discontinued antiplatelet drugs, 20.4% reported having encountered cerebral infarction and 3.7% reported encountering myocardial infarction; among those who discontinued anticoagulants, 13.6% reported encountering cerebral embolism and 5.4% reported encountering pulmonary embolism. However, among the respondents who continued antiplatelet drugs and those who continued anticoagulants, 26.3% and 27.2%, respectively, encountered an unexpected increase in