A novel surgical approach using the "lateral corridor" for minimally invasive oblique lumbar interbody fusion at L5-S1: a clinical series and technical note.

PURPOSE: The minimally invasive oblique lumbar interbody fusion (MI-OLIF) L5-S1 was introduced to overcome the limitations of conventional fusion techniques, however, MI-OLIF is not possible using the standard method due to vascular structures in some cases. We aimed to introduce the "lateral corridor" and report the details of the surgical technique with a clinical case series. METHODS: We utilized the lateral access route of the left common iliac vein and named it the "lateral corridor", to distinguish the technique from the standard technique (central corridor). The type and frequency of branch vessels that required additional manipulations were reviewed, and the frequency of intraoperative vascular injury was investigated. RESULTS: Among the 107 patients who underwent MI-OLIF L5-S1, 26 patients (24.3%) who received the "lateral corridor" technique were included. Branch vessel ligation was required in 42.3% of the patients. The types of branch vessels that required ligation were seven cases (26.9%) of the iliolumbar vein (ILV) and six cases (23.1%) of ascending lumbar vein (ALV). The ILV and ALV were ligated in two cases. None of the patients developed intraoperative vascular injuries. CONCLUSION: We introduced the "lateral corridor" as an alternative approach for MI-OLIF L5-S1, implemented it in 24.3% of the patient cohort, and reported favorable outcomes devoid of vascular complications. The "lateral corridor" necessitated ligation of the ILV or ALV in 42.3% of cases. The "lateral corridor" approach appears to be a promising surgical technique, offering feasibility even in instances where the vascular anatomy precludes the employment of the conventional approach.

The Impact of Persistent Low Weight Status on the Occurrence of Vertebral Fractures: A Nationwide Population-Based Cohort Study.

BACKGROUND: Although, being underweight is commonly associated with osteoporosis and sarcopenia, its association with vertebral fractures (VFs), is less well researched. We investigated the influence of cumulative, chronic periods of low weight and changes in body weight on VF development. METHODS: We used a nationwide, population-based database with data on people (> 40 years) who attended three health screenings between January 1, 2007, and December 31, 2009 to assess the incidence of new VFs. Cox proportional hazard analyses were used to establish the hazard ratios (HRs) for new VFs based on the degree of body mass index (BMI), the cumulative numbers of underweight participants, and temporal change in weight. RESULTS: Of the 561,779 individuals in this analysis, 5,354 (1.0%) people were diagnosed three times, 3,672 (0.7%) were diagnosed twice, and 6,929 (1.2%) were diagnosed once. The fully adjusted HR for VFs in underweight individuals was 1.213. Underweight individuals diagnosed only once, twice, or three times had an adjusted HR of 0.904, 1.443, and 1.256, respectively. Although the adjusted HR was higher in adults who were consistently underweight, there was no difference in those who experienced a temporal change in body weight. BMI, age, sex, and household income were significantly associated with VF incidence. CONCLUSION: Low weight is a risk factor for VFs in the general population. Given the significant correlation between cumulative periods of low weight and the risk of VFs, it is necessary to treat underweight patients before a VF to prevent its development and other osteoporotic fractures.

Carnosic Acid Attenuates an Early Increase in ROS Levels during Adipocyte Differentiation by Suppressing Translation of Nox4 and Inducing Translation of Antioxidant Enzymes.

The objective of this study was to investigate molecular mechanisms underlying the ability of carnosic acid to attenuate an early increase in reactive oxygen species (ROS) levels during MDI-induced adipocyte differentiation. The levels of superoxide anion and ROS were determined using dihydroethidium (DHE) and 2'-7'-dichlorofluorescin diacetate (DCFH-DA), respectively. Both superoxide anion and ROS levels peaked on the second day of differentiation. They were suppressed by carnosic acid. Carnosic acid attenuates the translation of NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 4 (Nox4), p47phox, and p22phox, and the phosphorylation of nuclear factor-kappa B (NF-κB) and NF-κB inhibitor (IkBa). The translocation of NF-κB into the nucleus was also decreased by carnosic acid. In addition, carnosic acid increased the translation of heme oxygenase-1 (HO-1), γ-glutamylcysteine synthetase (γ-GCSc), and glutathione S-transferase (GST) and both the translation and nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2). Taken together, these results indicate that carnosic acid could down-regulate ROS level in an early stage of MPI-induced adipocyte differentiation by attenuating ROS generation through suppression of NF-κB-mediated translation of Nox4 enzyme and increasing ROS neutralization through induction of Nrf2-mediated translation of phase II antioxidant enzymes such as HO-1, γ-GCS, and GST, leading to its anti-adipogenetic effect.

Calorie Restriction Effect of Heat-Processed Onion Extract (ONI) Using In Vitro and In Vivo Animal Models.

Onion (Allium cepa L.) is widely consumed as food or medicinal plant due to its well-defined health benefits. The antioxidant and antihyperlipidemic effects of onion and its extracts have been reported well. However, very limited information on anti-hyperglycemic effect is available in processed onion extracts. In our previous study, we reported that Amadori rearrangement compounds (ARCs) produced by heat-processing in Korean ginseng can reduce carbohydrate absorption by inhibiting intestinal carbohydrate hydrolyzing enzymes in both in vitro and in vivo animal models. To prove the enhancement of anti-hyperglycemic effect and ARCs content by heat-processing in onion extract, a correlation between the anti-hyperglycemic activity and the total content of ARCs of heat-processed onion extract (ONI) was investigated. ONI has a high content of ARCs and had high rat small intestinal sucrase inhibitory activity (0.34 ± 0.03 mg/mL, IC50) relevant for the potential management of postprandial hyperglycemia. The effect of ONI on the postprandial blood glucose increase was investigated in Sprague Dawley (SD) rats fed on sucrose or starch meals. The maximum blood glucose levels (Cmax) of heat-processed onion extract were significantly decreased by about 8.7% (from 188.60 ± 5.37 to 172.27 ± 3.96, p < 0.001) and 14.2% (from 204.04 ± 8.73 to 175.13 ± 14.09, p < 0.01) in sucrose and starch loading tests, respectively. These results indicate that ARCs in onion extract produced by heat-processing have anti-diabetic effect by suppressing carbohydrate absorption via inhibition of intestinal sucrase, thereby reducing the postprandial increase of blood glucose. Therefore, enhancement of ARCs in onion by heat-processing might be a good strategy for the development of the new product on the management of hyperglycemia.

Antioxidant and Anti-Osteoporosis Activities of Chemical Constituents of the Stems of Zanthoxylum piperitum.

Two new lignans, zanthoxyloside C (1) and zanthoxyloside D (2), together with nine known compounds comprising lignans (3-5), flavonoids (6-8), and phenolics (9-11), were isolated from the methanol extract of the stems of Zanthoxylum piperitum. All isolates were evaluated for their antioxidant and anti-osteoporotic activities using oxygen radical absorbance capacity (ORAC), cupric reducing antioxidant capacity (CUPRAC), and tartrate-resistant acid phosphatase (TRAP) assays. Compounds 7-10 showed peroxyl radical-scavenging capacities and 4, 6-7, and 9 showed reducing capacities. Moreover, compounds 3, 6-9, and 11 significantly suppressed TRAP activities. These results indicated that the stems of Z. piperitum could be an excellent source for natural antioxidant and anti-osteoporosis.

Anti-Osteoclastic Activity of Artemisia capillaris Thunb. Extract Depends upon Attenuation of Osteoclast Differentiation and Bone Resorption-Associated Acidification Due to Chlorogenic Acid, Hyperoside, and Scoparone.

The present study attempts to elucidate the anti-osteoporotic activity of Artemisia capillaris Thunb. in the form of anti-osteoclastic effect and responsible bioactive compounds. The contents of chlorogenic acid, caffeic acid, hyperoside, isoquercitrin, isochlorogenic acid A, and scoparone in Artemisia capillaris hydroethanolic extract (ACHE) were 38.53, 0.52, 4.07, 3.03, 13.90, and 6.59 mg/g, respectively. ACHE diminished osteoclast differentiation and bone resorption due to chlorogenic acid, hyperoside, and scoparone. In addition, ACHE attenuated acidification as well as reducing tumor necrosis factor receptor-associated factor 6 (TRAF6) expression and its association with vacuolar H⁺-adenosine triphosphatase (V-ATPase). Furthermore, chlorogenic acid, hyperoside, and scoparone from A. capillaris abrogated the association of V-ATPase with TRAF6, suggesting that the blockage of bone resorption by A. capillaris was partially mediated by reducing acidification through down-regulating interaction of V-ATPase with TRAF6 due to scoparone as well as chlorogenic acid and hyperoside. These results imply that the anti-osteoclastic effect of A. capillaris through down-regulating osteoclast differentiation and bone resorption may contribute to its anti-osteoporotic effect.

Antioxidant and Anti-Osteoporotic Activities of Aromatic Compounds and Sterols from Hericium erinaceum.

Hericium erinaceum, commonly called lion's mane mushroom, is a traditional edible mushroom widely used in culinary applications and herbal medicines in East Asian countries. In this study, a new sterol, cerevisterol 6-cinnamate (6), was isolated from the fruiting bodies of H. erinaceum together with five aromatic compounds 1-5 and five sterols 7-11. The chemical structures of these compounds were elucidated using chemical and physical methods and comparison of HRESIMS, ¹D-NMR (¹H, 13C, and DEPT) and 2D-NMR (COSY, HMQC, HMBC, and NOESY) spectra with previously reported data. The antioxidant and anti-osteoporotic activities of extracts and the isolated compounds 1-11 were investigated. All compounds exhibited peroxyl radical-scavenging capacity but only compounds 1, 3, and 4 showed potent reducing capacity. Moreover, compounds 1, 2, 4, and 5 showed moderate effects on cellular antioxidant activity and inhibited the receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclastic differentiation. These results suggested that H. erinaceum could be utilized in the development of natural antioxidant and anti-osteoporotic nutraceuticals and functional foods.

Scoparone attenuates RANKL-induced osteoclastic differentiation through controlling reactive oxygen species production and scavenging.

Scoparone, one of the bioactive components of Artemisia capillaris Thunb, has various biological properties including immunosuppressive, hepatoprotective, anti-allergic, anti-inflammatory, and antioxidant effects. This study aims at evaluating the anti-osteoporotic effect of scoparone and its underlying mechanism in vitro. Scoparone demonstrated potent cellular antioxidant capacity. It was also found that scoparone inhibited the receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation and suppressed cathepsin K and tartrate-resistant acid phosphatase (TRAP) expression via c-jun N-terminal kinase (JNK)/extracellular signal-regulated kinase (ERK)/p38-mediated c-Fos-nuclear factor of activated T cells, cytoplasmic 1 (NFATc1) signaling pathway. During osteoclast differentiation, the production of general reactive oxygen species (ROS) and superoxide anions was dose-dependently attenuated by scoparone. In addition, scoparone diminished NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 1 (Nox1) expression and activation via the tumor necrosis factor receptor-associated factor 6 (TRAF6)-cSrc-phosphatidylinositol 3-kinase (PI3k) signaling pathway and prevented the disruption of mitochondrial electron transport chain system. Furthermore, scoparone augmented the expression of superoxide dismutase 1 (SOD1) and catalase (CAT). The overall results indicate that the inhibitory effect of scoparone on RANKL-induced osteoclast differentiation is attributed to the suppressive effect on ROS and superoxide anion production by inhibiting Nox1 expression and activation and protecting the mitochondrial electron transport chain system and the scavenging effect of ROS resulting from elevated SOD1 and CAT expression.

The anti-osteoporosis and antioxidant activities of chemical constituents from Chrysanthemum indicum flowers.

Two new compounds, chrysinoneside A (1) and (-)-trans-chrysanthenol-6-O-ß-D-glucopyranoside (2), along with 17 known compounds (3-19) were isolated from Chrysanthemum indicum flowers. The total phenolic and flavonoid contents of various fractions were determined. The EtOAC fraction had the highest total phenolic content (525.84 ± 23.51 mg GAE/g DR) and the total flavonoid content (63.49 ± 3.32 mg QE/g DR). The EtOAc and water fractions showed the greatest peroxyl radical-scavenging capacity and the ability to reduce Cu(I) ions, with ORAC and CUPRAC values ranging from 24.00 ± 0.44 to 28.06 ± 1.35 and 16.90 ± 0.51 to 49.77 ± 0.97 µM, respectively. Compounds 5-11, 18, and 19 displayed strong effects in both peroxyl radical-scavenging and reducing capacity assays at a concentration of 10 µM. The anti-osteoporosis activity of these compounds was also evaluated. Compounds 10, 13, and 19 exhibited the most potent tartrate-resistant acid phosphatase activity in receptor activator of nuclear factor-κB ligand-induced osteoclastic RAW 264.7 cells with values of 105.95 ± 1.18, 110.32 ± 3.95, and 112.58 ± 6.42%, respectively.

Identification and biological evaluation of flavonoids from the fruits of Prunus mume.

This Letter describes the identification of potent antioxidant and anti-osteoporosis agents from the fruits of Prunus mume. From the methanol extract, a novel flavan dimer, characterized as 2ß,3ß-epoxy-5,7,4'-trihydroxyflavan-(4α→8)-epicatechin (1), was isolated along with five known flavonoids (2-6). Their structures were determined based on extensive spectroscopic analysis, including IR, HRESIMS, 1D- and 2D-NMR, and CD spectra. The antioxidant activities of compounds 1-6 were evaluated in terms of their peroxyl radical-scavenging (Trolox equivalent) and reducing capacities. All isolates showed potent peroxyl radical-scavenging and reducing activities at concentrations of 1-10 µM. Among them, compounds 1 and 2 were the most active at 1 µM. Anti-osteoporosis activities were investigated using both murine osteoblastic MC3T3-E1 cells and osteoclastic RAW 264.7 cells. Compounds 2, 3, and 6 significantly stimulated the differentiation of osteoblastic MC3T3-E1 cells to increase collagen synthesis or mineralization functions of osteoblasts. Compounds 1, 3, 4, and 6 significantly suppressed tartrate-resistant acid phosphatase (TRAP) activity in receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastic RAW 264.7 macrophage cells.

Anti-osteoporotic and antioxidant activities of chemical constituents of the aerial parts of Ducrosia ismaelis.

A new pterocarpan glycoside, glycinol-3-O-ß-D-glucopyranoside (1), and a new dihydrochalcone glycoside, ismaeloside A (2), were isolated together with 13 known compounds, including several flavonoids (3-8), lignans (9-11), and phenolic compounds (12-15), from the methanol extract of the aerial parts of Ducrosia ismaelis. The chemical structures of these compounds were elucidated from spectroscopic data and by comparison of these data with previously published results. The anti-osteoporotic and antioxidant activities of the isolated compounds were assessed using tartrate-resistant acid phosphatase (TRAP), oxygen radical absorbance capacity (ORAC), and reducing capacity assays. Compound 15 exhibited a dose-dependent inhibition of osteoclastic TRAP activity with a TRAP value of 86.05±6.55% of the control at a concentration of 10 µM. Compounds 1, 3-5, and 8 showed potent peroxyl radical-scavenging capacities with ORAC values of 22.79±0.90, 25.57±0.49, 20.41±0.63, 26.55±0.42, and 24.83±0.12 µM Trolox equivalents (TE) at 10 µM, respectively. Only compound 9 was able to significantly reduce Cu(I) with 23.44 µM TE at a concentration of 10 µM. All of the aforementioned compounds were isolated for the first time from a Ducrosia species.

A new phenylpropanoid and an alkylglycoside from Piper retrofractum leaves with their antioxidant and α-glucosidase inhibitory activity.

Two new compounds, piperoside (1) and isoheptanol 2(S)-O-ß-D-xylopyranosyl (1→6)-O-ß-D-glucopyranoside (11), along with 10 known compounds 3,4-dihydroxyallylbenzene (2), 1,2-di-O-ß-D-glucopyranosyl-4-allylbenzene (3), tachioside (4), benzyl-O-ß-D-glucopyranoside (5), icariside F2 (6), dihydrovomifoliol-3'-O-ß-D-glucopyranoside (7), isopropyl O-ß-D-glucopyranoside (8), isopropyl primeveroside (9), n-butyl O-ß-D-glucopyranoside (10), isoheptanol 2(S)-O-ß-D-apiofuranosyl-(1→6)-O-ß-D-glucopyranoside (12), were isolated from the leaves of Piper retrofractum. Their structures were determined from 1D-NMR, 2D-NMR, and HR-ESI-MS spectral, a modified Mosher's method, and comparisons with previous reports. All of the isolated compounds showed modest α-glucosidase inhibitory (4.60±1.74% to 11.97±3.30%) and antioxidant activities under the tested conditions.

Nrf2-mediated HO-1 induction coupled with the ERK signaling pathway contributes to indirect antioxidant capacity of caffeic acid phenethyl ester in HepG2 cells.

The objective of this study is to investigate the contributing effect of the nuclear transcription factor-erythroid 2-related factor 2 (Nrf2)-mediated signaling pathway on the indirect antioxidant capacity of caffeic acid phenethyl ester (CAPE) against oxidative stress in HepG2 cells. The result of an antioxidant response element (ARE)-luciferase assay showed that CAPE stimulated ARE promoter activity resulting in increased transcriptional and translational activities of heme oxygenase-1 (HO-1). In addition, CAPE treatment enhanced Nrf2 accumulation in the nucleus and the post-translational phosphorylation level of extracellular signal-regulated kinase (ERK) among several protein kinases tested. Treatment with ERK inhibitor U126 completely suppressed CAPE-induced ERK phosphorylation and HO-1 expression, but it only partly inhibited CAPE-induced Nrf2 accumulation and ARE promoter. Using the 2',7'-dichlorofluorescein-diacetate (DCFH-DA) method, the cellular antioxidant capacity of CAPE against 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH)- or H2O2-induced oxidative stress also was shown to be partially suppressed by the ERK inhibitor. From the overall results it is proposed that the indirect antioxidant activity of CAPE against oxidative stress in HepG2 cells is partially attributed to induction of HO-1, which is regulated by Kelch-like erythroid-cell-derived protein with CNC homology (ECH)-associated protein 1 (Keap1)-independent Nrf2 activation relying on post-translational phosphorylation of ERK.

Genistein inhibits osteoclastic differentiation of RAW 264.7 cells via regulation of ROS production and scavenging.

Genistein, a phytoestrogen, has been demonstrated to have a bone-sparing and antiresorptive effect. Genistein can inhibit the osteoclast formation of receptor activator of nuclear factor-κB ligand (RANKL)-induced RAW 264.7 cells by preventing the translocation of nuclear factor-κB (NF-κB), a redox-sensitive factor, to the nucleus. Therefore, the suppressive effect of genistein on the reactive oxygen species (ROS) level during osteoclast differentiation and the mechanism associated with the control of ROS levels by genistein were investigated. The cellular antioxidant capacity and inhibitory effect of genistein were confirmed. The translation and activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 1 (Nox1), as well as the disruption of the mitochondrial electron transport chain system were obviously suppressed by genistein in a dose-dependent manner. The induction of phase II antioxidant enzymes, such as superoxide dismutase 1 (SOD1) and heme oxygenase-1 (HO-1), was enhanced by genistein. In addition, the translational induction of nuclear factor erythroid 2-related factor 2 (Nrf2) was notably increased by genistein. These results provide that the inhibitory effects of genistein on RANKL-stimulated osteoclast differentiation is likely to be attributed to the control of ROS generation through suppressing the translation and activation of Nox1 and the disruption of the mitochondrial electron transport chain system, as well as ROS scavenging through the Nrf2-mediated induction of phase II antioxidant enzymes, such as SOD1 and HO-1.

Lumbar radiculopathy and fracture risk: A Korean nationwide population-based cohort study.

INTRODUCTION: Lumbar radiculopathy is a common disease with a high economic burden, and fractures in adults are a significant public health problem. However, studies of the relationship between lumbar radiculopathy and fractures are scarce. We investigated the fracture risk in patients with lumbar radiculopathy. METHODS: This nationwide retrospective cohort study identified 815,101 patients with lumbar radiculopathy and randomly matched individuals without lumbar radiculopathy (1:1) who were included in the Korean National Health Insurance System in 2012. Cox proportional hazards regression analyses were performed to calculate the hazard ratio (HR) for fracture risk in patients with lumbar radiculopathy. RESULTS: The study included 301,347 patients with lumbar radiculopathy and matched 289,618 individuals without lumbar radiculopathy. Compared to individuals without lumbar radiculopathy, patients with lumbar radiculopathy had a 27 % increased fracture risk (adjusted HR = 1.27, 95 % confidence interval = 1.24-1.31). The Kaplan-Meier plot showed a significantly higher fracture incidence in patients with lumbar radiculopathy than in individuals without lumbar radiculopathy at all times. CONCLUSION: Lumbar radiculopathy is significantly associated with fracture risk.

Effectiveness of vancomycin powder for preventing postoperative spinal infection.

OBJECTIVE: This study aimed to assess the effectiveness of Vancomycin Power (VP) and the occurrence of resistant organisms after four-year of routine VP use. METHODS: The study included 1063 patients who underwent posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) between January 2010 and February 2020. Intrawound VP was applied to all instrumented fusions starting in January 2016. The patients were divided into two groups: those who did not apply VP (non-VP) (n = 605) between 2010 and 2015, and those who did apply VP (VP) (n = 458) between 2016 and 2020. The baseline characteristics, clinical symptoms, infection rate, and causative organisms were compared between the two groups. RESULTS: The rate of PSI was not significantly different between the non-VP group (1.32 %, n = 8) and the VP group (1.09 %, n = 5). Although adjusted by diabetes mellitus, VP still did not show statistical significance (OR = 0.757 (0.245-2.345), p = 0.630). There were no critical complications that were supposed to relation with vancomycin powder. In the 13 cases of PSI, seven pathogens were isolated, with a gram-negative organism identified in the non-VP group. However, the type of organism was not significantly different between the two groups. CONCLUSIONS: The use of intrawound VP may not affect the PSI and occurrence of resistant organism and may not cause critical complications. Therefore, clinicians may decide whether to use VP for preventing PSI not worrying about its safety.

Scopoletin and scopolin isolated from Artemisia iwayomogi suppress differentiation of osteoclastic macrophage RAW 264.7 cells by scavenging reactive oxygen species.

Artemisia iwayomogi has been used as a folk medicine for treating various diseases including inflammatory and immune-related diseases. Scopoletin (1) and scopolin (2) were isolated from this species. Scopoletin (1) showed more potent peroxyl radical-scavenging capacity, reducing capacity, and cellular antioxidant capacity compared to scopolin (2). The inhibitory effect of 1 on the receptor activator of nuclear factor κB ligand-induced osteoclastic differentiation of RAW 264.7 macrophage cells was also more potent than that of 2. The production of general reactive oxygen species (ROS) and superoxide anions during differentiation of preosteoclastic RAW 264.7 cells into osteoclasts was attenuated by compounds 1 and 2. These findings indicate that the suppressive effects of 1 and 2 on the differentiation of preosteoclastic RAW 264.7 cells is partially due to their intracellular antioxidant capacity, as they can scavenge ROS and play an important signaling role in the differentiation process.

Computed Tomography Evaluation of Percutaneous Pedicle Screws Inserted during Minimally Invasive Transforaminal Lumbar Interbody Fusion: Long-term Follow-up Results of Screw Violation.

Background: To evaluate the accuracy of percutaneous pedicle screw (PPS) insertion in degenerative lumbar disease treated with minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) and to analyze risk factors and long-term clinical outcomes of screw violation. Methods: Sixty-two consecutive patients (262 screws) were included. Based on postoperative computed tomography (CT) axial images, a PPS that perforated out of the pedicle was classified into a violation group, while screws surrounded by pedicular cortical bone were classified into a correct group. A logistic regression model was used for risk factor analysis of violation. We also observed the long-term clinical outcomes using the Oswestry disability index and visual analog scale. Results: Of the 262 screws, 14 (5.3%) were considered to be violated (10 medial violations and 4 lateral violations). All violations of S1 and L5 were in the medial direction. In contrast, entire violations of L4 were always lateral and of the 2 violations of L3, one was lateral and the other was medial. There were no cases of superior or inferior violation. The mean pedicle convergence angle (CA) was significantly higher in the violation group (mean ± standard deviation, 27.0° ± 6.2°) than in the correct group (21.7° ± 5.4°). There were no significant differences according to vertebral rotational angle, body mass index, bone mineral density, and surgical timing (learning curve) between the two groups. Logistic regression analyses demonstrated that a high CA was a significant risk factor for pedicle wall violation (p = 0.002). There were no significant differences in clinical or radiographic results between the two groups in 60 patients who were followed up for more than 1 year and in 40 patients who were followed up for more than 5 years. There were 2 patients who required reoperation to replace a screw due to leg pain. Conclusions: With PPS insertion during MI-TLIF, the rate of pedicle violation was 5.3% (14/262). An understanding of the anatomical characteristics of each vertebra and the unique structures of the patient is essential to prevent pedicle violations. Even in the violation group, PPS fixation was found to be a safe and useful procedure with successful long-term radiographic and clinical outcomes.

Underweight as a risk factor for vertebral fractures in the South Korean population.

BACKGROUND CONTEXT: Being underweight is a known risk factor for osteoporosis and sarcopenia that is strongly associated with vertebral fractures, particularly in the elderly. Being underweight can accelerate bone loss, contribute to impaired coordination, and increase fall risk in the elderly and the general population. PURPOSE: This study aimed to identify the degree of underweight as a risk factor for vertebral fractures in the South Korean population. STUDY DESIGN: Retrospective cohort study based on national health insurance database. PATIENT SAMPLE: Participants were included from nationwide regular health check-ups conducted by the Korean National Health Insurance Service in 2009. Participants were followed up from 2010 to 2018 to identify the incidence of newly developed fractures. OUTCOME MEASURES: The incidence rate (IR) was defined as the incident per 1,000 person-years (PY). Vertebral fracture development risk was analyzed using Cox proportional regression analysis. Subgroup analysis was performed based on several factors, including age, sex, smoking status, alcohol consumption, physical activity, and household income. METHODS: Based on body mass index, the study population was categorized into normal weight (18.50-22.99 kg/m2), mild underweight (17.50-18.49 kg/m2), moderate underweight (16.50-17.49 kg/m2), and severe underweight (<16.50 kg/m2) groups. Cox proportional hazards analyses were performed to calculate the hazard ratios for vertebral fractures based on the degree of underweight with respect to normal weight to identify the associated risk. RESULTS: This study evaluated 962,533 eligible participants, of whom 907,484 were classified as normal weight, 36,283 as mild underweight, 13,071 as moderate underweight, and 5,695 as severe underweight. The adjusted hazard ratio of vertebral fractures increased as the degree of underweight increased. Severe underweight was associated with a higher likelihood of vertebral fracture. The adjusted hazard ratio was 1.11 (95% confidence interval [CI], 1.04-1.17) in the mild underweight group, 1.15 (1.06-1.25) in the moderate underweight group, and 1.26 (1.14-1.40) in the severe underweight group when compared with the normal weight group. CONCLUSIONS: Underweight is a risk factor for vertebral fractures in the general population. Furthermore, severe underweight was associated with a higher risk of vertebral fractures, even after adjustment for other factors. Clinicians could provide real-world evidence that being underweight carries the risk of vertebral fractures.

Incidence and Risk Factors for Wound Revision after Surgical Treatment of Spinal Metastasis: A National Population-Based Study in South Korea.

Wound complications are commonly seen after surgeries for metastatic spine tumors. While numerous studies have pinpointed various risk factors, there is ongoing debate. Therefore, this study aimed to verify various factors that are still under debate utilizing the comprehensive Korean National Health Insurance Service database. We identified and retrospectively reviewed a cohort of 3001 patients who underwent one of five surgical treatments (corpectomy, decompression and instrumentation, instrumentation only, decompression only, and vertebroplasty) for newly diagnosed spinal metastasis between 2009 and 2017. A Cox regression analysis was performed to determine the risk factors. A total of 197 cases (6.6%) of wound revision were found. Only the surgical method and Charlson comorbidity index were significantly different between the group that underwent wound revision and the group that did not. Regarding surgical methods, the adjusted hazard ratios for decompression only, corpectomy, instrumentation and decompression, and instrumentation only were 1.3, 2.2, 2.2, and 2.4, with these ratios being compared to the vertebroplasty group (p for trend = 0.02). In this regard, based on a sizable South Korean cohort, both surgical methods and medical comorbidity were found to be associated with the wound revision rate among spinal surgery patients for spinal metastasis.