The incidence and risk factors for extensive epidural cement leakage in cement-augmented pedicle screw fixation: a multicenter retrospective study.

INTRODUCTION: In cement-augmented pedicle screw fixation (CAPSF), epidural cement leakage (CL) is a frequently reported complication with the potential for neural injury, especially when it is extensive. To date, there has been no reports discussing basivertebral foramen morphology and pedicle screw placement, which is critical in the analysis of the risk of extensive epidural CL. Thus, this study aimed to identify the incidence and risk factors for extensive epidural CL in osteoporotic patients with CAPSF. MATERIALS AND METHODS: 371 osteoporotic patients using 1898 cement-augmented screws were included. Preoperative computed tomography (CT) was utilized to characterize basivertebral foramen morphology. Following CAPSF, the severity of epidural CL, the implantation position of pedicle screw and cement extension within the vertebral body were determined by postoperative CT. In this study, significant risk factors for extensive epidural CL were identified through logistic regression analysis. RESULTS: There were 19 patients (5.1%) and 32 screws (1.7%) with extensive epidural CL. Nine patients (involving 19 screws) had neurological symptoms. The independent risk factors for patients with extensive epidural CL were decreased BMD and increased number of augmented screws. Significant predictors for extensive epidural CL were a magistral type of basivertebral foramen, more volume of cement injected, solid screw, a shallower screw implantation, and the smaller distance between the tip of the screw and the midline of vertebral body. CONCLUSION: Extensive epidural CL risk was significant in CAPSF when a magistral basivertebral foramen was present; solid screws and more volume of cement were used; and screw tip was implanted shallower or closer to the midline.

Establishment of a novel risk prediction model for recompression of augmented vertebrae at the thoracolumbar junction and modified puncture technique for prevention: a multicenter retrospective study.

OBJECTIVE: Recompression of augmented vertebrae (RCAV) is often seen after percutaneous kyphoplasty (PKP), especially at the thoracolumbar junction. The authors aimed to develop and validate a risk prediction model (nomogram) for RCAV and to evaluate the efficacy of a modified puncture technique for RCAV prevention after PKP for thoracolumbar osteoporotic vertebral fractures (OVFs). METHODS: Patients who underwent PKP for single thoracolumbar OVFs (T10-L2) between January 2016 and October 2020 were reviewed and followed up for at least 2 years. All patients were randomly divided into a training group (70%) and a validation group (30%). Relevant potential data affecting recompression were collected. Predictors were screened by using binary logistic regression analysis to construct the nomogram. Calibration and receiver operating characteristic curves were used to evaluate the consistency of the prediction models. Finally, the efficacy of the modified puncture technique for prevention of RCAV in OVF patients with a preoperative intravertebral cleft (IVC) was further demonstrated through binary logistic regression analysis. RESULTS: Overall, 394 patients were included and 116 of them (29.4%) sustained RCAV. The independent risk factors included decreased bone mineral density, lower level of serum 25-hydroxy vitamin D3, larger C7-S1 sagittal vertical axis (SVA), preoperative IVC, and solid-lump cement distribution. The area under the curve (AUC) of the prediction model was 0.824 in the training group and 0.875 in the validation group patients. The calibration curve indicated the predictive power of this nomogram, with the preoperative IVC having the highest prediction accuracy (AUC 0.705). The modified puncture technique significantly reduced the incidence of RCAV by enhancing bone cement distribution into a sufficiently diffused distribution in OVF patients with preoperative IVC. CONCLUSIONS: The nomogram prediction model had satisfactory accuracy and clinical utility for identification of patients at low and high risk of postoperative RCAV. Patients at high risk of postoperative RCAV might benefit from the target puncture technique and vitamin D supplementation as well as effective antiosteoporotic therapies.

Electroacupuncture alleviates intestinal inflammation and barrier dysfunction by activating dopamine in a rat model of intestinal ischaemia.

BACKGROUND: To investigate whether the mechanism underlying the anti-inflammatory effects of electroacupuncture (EA) at ST36 involves dopamine (DA) and its receptor and whether it is mediated by the vagus nerve in a rat model of intestinal ischaemia-reperfusion (I/R) injury. METHODS: Rats were subjected to gut ischaemia for 30 min and then received EA for 30 min with or without abdominal vagotomy or intraperitoneal administration of butaclamol (D1 receptor antagonist) or spiperone (D2 receptor antagonist). Plasma levels of DA and tumour necrosis factor (TNF)-α were assessed 1 or 4 h after reperfusion. Myeloperoxidase (MPO) activity and malondialdehyde (MDA) content in intestinal tissues were assessed using enzyme-linked immunosorbent assay (ELISA) kits. Intestinal tissue injury was assessed by observation of the pathological lesions and permeability to 4 kDa fluorescein isothiocyanate (FITC)-dextran. RESULTS: EA significantly increased levels of DA and lowered levels of TNF-α. EA also inhibited intestinal levels of MPO and MDA and intestinal tissue injury and decreased intestinal permeability to FITC-dextran. Abdominal vagotomy and intraperitoneal administration of butaclamol (but not spiperone) inhibited the effects of EA. CONCLUSION: These findings suggest that EA at ST36 could attenuate intestinal I/R-induced inflammatory injury and that the underlying mechanism may involve EA-induced increases in levels of DA, mediated by the vagus nerve and D1 receptors.

Cement Distribution Patterns in Osteoporotic Vertebral Compression Fractures with Intravertebral Cleft: Effect on Therapeutic Efficacy.

OBJECTIVE: To determine cement distribution patterns on therapeutic efficacy after percutaneous vertebroplasty treatment of osteoporotic vertebral compression fractures (OVCFs) with intravertebral cleft (IVC). METHODS: Patients who were treated with percutaneous vertebroplasty for single OVCFs with IVC and met this study's inclusion criteria were retrospectively reviewed. The follow-up period was at least 2 years. Distribution patterns of cement in the IVC area were respectively specified into 2 groups: group 1: solid lump distribution pattern (n = 22); group 2: the comparatively diffused pattern (n = 90). Radiologic and clinical parameters were analyzed and compared. Then, associations of recollapse with covariates and a risk score were further analyzed and developed to predict recollapse of the augmented vertebrae. RESULTS: At the immediate postoperative period, all patients benefited from significant improvement in vertebrae height and kyphotic angle correction. However, significant recollapse was observed at the 2 years postoperative follow-up for the patients in group 1. Furthermore, we found that preoperative severe kyphotic deformity (a cutoff value of 12.5°), solid lump cement distribution pattern, and larger reduction angle (a cutoff value of 8.3°) was significantly associated with increased risk for recollapse. A risk score was developed based on the number of risk factors present in each patient and the receiver operating characteristic curve of the risk score generated an area under the curve of 0.788 (95% confidence interval 0.702-0.873, P = 0.000). CONCLUSIONS: The comparatively diffused pattern shows better long-term radiologic and clinical outcomes for the treatment for OVCFs with IVC. A risk score can be used to predict the incidence of recollapse.

Valproic Acid Treatment Inhibits Vasopermeability and Improves Survival in Rats With Lethal Scald Injury.

The aim of this study was to examine whether administration of valproic acid (VPA), a histone deacetylase inhibitor, inhibits proinflammatory mediators and ameliorate visceral vasopermeability both in a rat model of major burn, and also in rat cultured endothelial cells stimulated with permeability evoking mediators. SD rats were subjected to a 50% TBSA full-thickness scald injury, and treated with either saline or VPA (300 mg/kg) intraperitoneally. Pulmonary vascular endothelial growth factor (VEGF), myeloperoxidase (MPO), pulmonary microvascular permeability, water content, and acetylation of histone H3K9 of lungs were evaluated. In addition, pulmonary microvascular endothelial cells (PMECs) from male SD rats were cultured. With then, MPO, VEGF, histone acetylation, and the permeability of PMECs were investigated. Lethal scald injury resulted in a significant increase in microvascular permeability and water content of lung, accompanied by a significant elevation of the content of VEGF and activity of MPO, and a decrease of histone acetylation. VPA treatment significantly alleviated the microvascular permeability and water content of lung, lowered the levels of VEGF and MPO, and promoted acetylation of histone H3K9 following scald injury. Moreover, VPA reduced permeability of monolayer PMECs subjected to scald serum challenge, reduced the level of MPO and VEGF in supernatants, and promoted acetylation of histone H3K9 in PMECs. These results indicated that VPA can protect pulmonary microvascular endothelial barrier, alleviate proinflammatory mediators-evoked vascular hyperpermeability and tissue edema and improve the survival rate of rats subjected to lethal scald injury.

[Electroacupuncture at "Zusanli" (ST 36) Alleviates Myocardium Damage in Intestinal Ischemia-reperfusion Rats by Up-regulating Periphery Dopamine Level].

OBJECTIVE: To observe the effect of electroacupuncture (EA) of "Zusanli" (ST 36) on myocardium ischemic damage following intestinal ischemia-reperfusion (I/R) in rats. METHODS: Thirty SD rats were randomly divided into five groups:sham, I/R-1 h, I/R-4 h, EA-I/R-1 h and EA-I/R-4 h (n=6 in each group). The intestinal I/R model was established by occlusion of the superior mesenteric artery. EA (2 Hz/100 Hz, 2-3 mA) was applied to bilateral ST 36 for 30 min. In rats of the sham group, only the stomach was opened. Plasma dopamine (DA) and tumor necrosis factor (TNF)-α contents, and myocardial myeloperoxidase (MPO) activity and methane dicarboxylic aldehyde (MDA) content were assayed using ELISA, and plasma creastine kinase isoenzyme (CK-MB) and lactate dehydrogenese (LDH) activities were detected using a fully biochemical analyser. Myocardial pathological changes were observed under microscope after H.E. staining. RESULTS: Compared with the sham group, plasma DA content was significantly decreased in both I/R-1 h and I/R-4 h groups, while plasma TNF-α content and CK-MB and LDH activities, and myocardial MPO activity and MDA content in both I/R-1 h and I/R-4 h groups were obviously increased (P<0.05). After EA, the decreased plasma DA and the increased plasma TNF-α contents and the increased plasma CK-MB and LDH and myocardial MPO activities and MDA contents in the EA-I/R-1 h and EA-I/R-4 h groups were reversed (P<0.05). The inhibitory rates of EA on myocardial MDA content and MPO activity were 9% and 13% in the EA-I/R-1 h group and 30% and 15% in the EA-I/R-4 h group, respectively, suggesting a better protective effect of EA intervention on myocardium in the EA-I/R-4 h group. CONCLUSIONS: EA of ST 36 has a better protective action on myocardium in intestinal I/R injury rats, which may be related to its effects in up-regulating plasma DA level and down-regulating circulating pro-inflammatory factor TNF-α content, and reducing myocardial oxygen free radicals.