Anatomical study of the technique of the axis laminar screws and development of guide.

PURPOSE: To develop a bidirectional slide guide to assist screw placement in the axial lamina and to preliminarily discuss the accuracy and feasibility of auxiliary screw placement. METHODS: CT data from 40 randomly selected patients were imported into the software for modelling, and cross-pinning was used to simulate pinning. According to the different crossing methods of the upper and lower laminar screws, they are divided into two groups. In the software, the position of the needlepoint of each screw is accurately measured, and the needle point is kept unchanged to simulate the movable range of the screw tail under the condition that the body does not penetrate the cortical bone. The data were compared by grouping and gender. Finally, the guide was designed by combining the screw exit point and fine adjustment angle data of all patients with the centripetal principle of the slide rail. RESULTS: The needle exit data L1/L2/L3/L4 were 6.44 ± 0.52 mm, 7.05 ± 0.48 mm, 3.55 ± 0.75 mm and 5.09 ± 0.74 mm, respectively, and the fine adjustment angle of the slide rail was 10.51° ± 0.87°. There was no significant difference between the two groups or between men and women (p > 0.05). CONCLUSION: In this experiment, using the data obtained from the simulation of screw insertion, a two-way slide guide was designed to assist the insertion of axial laminar screws. The guide locks the screw outlet point to position and guides the screw inlet point, which improves the accuracy and safety of screw placement.

Application of the combination of three-dimensional visualization with a problem-based learning mode of teaching to spinal surgery teaching.

OBJECTIVE: To explore the application of the combination of three-dimensional visualization technology with a problem-based learning mode of teaching in clinical teaching related to spinal surgery. METHODS: A total of 106 5-year undergraduate students who majored in clinical medicine were selected as research subjects, and practiced in the Orthopaedics Department of the Affiliated Hospital of Xuzhou Medical University in 2021. These students were randomly divided into an experimental group and a control group, with 53 students in each group. The experimental group received a combination of three-dimensional visualization technology with the PBL teaching mode, while the control group was treated with the traditional teaching method. The teaching effects exhibited by these two groups were compared using tests and questionnaires that were administered after the teaching was completed. RESULTS: The theoretical test total scores of students in the experimental group were higher than those of students in the control group. The students in the two groups self-rated their classroom achievements, and the results attained by students in the experimental group were higher than those obtained by students in the control group (P < 0.05). The scores reported by students in the experimental group for interest in learning, classroom atmosphere, classroom interaction and teaching satisfaction were higher than those reported by students in the control group (P < 0.05). CONCLUSION: The application of a combination of 3D visualization technology with the PBL teaching mode to spinal surgery teaching can improve students' learning efficiency and interest and is conducive to cultivating students' clinical thinking.

Effect of medium with moderate temperature on patient's body temperature during percutaneous endoscopic lumbar discectomy.

PURPOSE: To explore the influence of irrigating fluid at different temperatures on patients' body temperature and local inflammatory mediators during spinal endoscopy. METHODS: 110 cases of intervertebral foramen surgery in our hospital from January 2019 to October 2021 were randomly divided into control group and observation group. Operations of both groups were performed by the same experienced chief physician. The observation group was irrigated with 37 °C constant temperature saline, while the control group was irrigated at room temperature. The effect was evaluated by monitoring the intraoperative temperature, postoperative VAS score and the levels of inflammatory factors, such as TNF-α, IL-1, IL-6 and IL-10 in drainage fluid. RESULTS: After 30 min of operation, overall temperature of the control group dropped significantly, and 50 cases (90.9%) had hypothermia, P < 0.05. There was no significant difference in preoperative VAS score between the two groups P > 0.05. The VAS score of observation group was significantly lower than that of control group at 6 h and 1 month after operation, P < 0.05. At 0, 3 and 6 h after operation, the values of TNF-α, IL-1, IL-6 and IL-10 in the observation group were significantly lower than those in the control group (P < 0.05). CONCLUSIONS: Isothermal flushing solution can reduce the incidence of hypothermia and effectively alleviate local inflammatory reaction.

[Study on the application of a new type of vertebral plate nail guide].

OBJECTIVE: To explore safety and accuracy of novel C2 laminar staple guide through in vitro experiments. METHODS: From January 2018 to June 2018, 40 patients who underwent three-dimensional CT of cervical spine were selected, including 21 males and 19 females, heighted from 165 to 180 cm with an average of (172.9±9.5) cm, aged from 38 to 55 years old (51.1±12.8) years old, excluding patients with axis lamina defect and hypoplasia. Two sets of 3D printed specimens were made from the three-dimensional CT data of cervical spine of each patient, and both of than were used for the in vitro nailing experiment. According to different nail placement methods, in vitro experimental part of this experiment was divided into guide nail placement group and hand nail placement group, 40 pieces in each group. At the same time, the three-dimensionalmodel of cervical spine of 40 patients was reconstructed on computer, and the ideal needle point data and inclination angle were obtained by computer simulation of the nail placement. This is 3D simulation nail placement group, 40 pieces. With vitro experiment, the risk level of screw placement, the position of needle exit point and inclination angle were measured in guide nail group and hand nail group. Based on the accuracy of needle point and inclination angle of nail path, the data of guide nail group, the hand nail group and 3D simulation nail group were compared, and the data of each group were statistically analyzed to determine the accuracy. RESULTS: In guide nail group, 75 screws were acceptable and 5 were dangerous. The acceptable rate was 94%, and the double cortical rate was 93%. There were 62 position-acceptable screws in hand nail group, and 18 positions were dangerous, with an acceptable rate of 78% and a double cortical rate of 33%. The difference between two groups was statistically significant (P<0.05). There was no significant difference in accuracy of needle exit point and inclination angle of nail path between guide nail group and 3D simulation nail group (P>0.05), but there was significant difference in the accuracy of needle exit point and inclination angle of nail path between hand nail group and 3D simulation nail group (P<0.05). CONCLUSION: The guide is universal, with stable structure, accurate guidance, and easy operation. It could be placed with bilateral lamina screws at the same time, shortening the time of nail placement, avoiding collision of two way cross screws, increase the rate of double cortex. Ultimately, efficiency and security can be improved.

MRGPRX2 mediates immediate-type pseudo-allergic reactions induced by iodine-containing iohexol.

BACKGROUND: Iohexol is a typical iodinated radiocontrast medium and widely used in clinical angiography. Hypersensitivity reactions induced by iohexol are common side effects known to increase the risk for patients. Iodine is the main functional group of iohexol, and it can induce delayed anaphylaxis. However, iohexol also induces immediate-type allergies, but the underlying mechanism is still not clear. MRGPRX2 is a key receptor present on mast cells, which mediates pseudo-allergic reactions induced by various drugs. METHODS: We aimed to verify the relationship between iohexol-induced anaphylactic reactions and MRGPRX2. MRGPRX2-mediated pseudo-allergic reactions induced by iohexol were investigated in vivo and in vitro using a mouse model of local and systemic anaphylaxis and mast cell degranulation assays, respectively. RESULTS: Iohexol caused pseudo-allergic reactions in wild-type (WT) mice by activating mast cells to release histamine and cytokines. However, it did not induce a similar phenomenon in KitW-sh/W-sh (MUT) mice. Iohexol stimulated intracellular calcium ion (Ca2+) influx in MRGPRX2-HEK293, MrgprB2-HEK293, and LAD2 cells but not in NC-HEK293 cells. After knockdown of MRGPRX2 expression in LAD2 cells, the degree of iohexol-induced degranulation was reduced. In addition, after structural modification of iohexol by removal of iodine, a reduction in iohexol-induced effects, such as local and systemic anaphylaxis in mice and degranulation of LAD2 cells, could be observed. Iohexol was shown to induce immediate-type pseudo-allergic reactions via MRGPRX2, which was dependent on the presence of iodine. CONCLUSIONS: Conclusively, inhibition of MRGPRX2-mediated mast cell degranulation and cytokine release is important to prevent iohexol-induced immediate-type pseudo-allergic reactions.

[Design of three-dimensional foraminal guide device and application in percutaneous endoscopic lumbar discectomy].

OBJECTIVE: To explore clinical application of the new three-dimensional foramen guide in percutaneous endoscopic lumbar discectomy. METHODS: Based on the principle of reverse positioning, a new three-dimensional foramen guide was designed. From May 2016 to May 2018, totally 40 patients with segmental lumbar disc herniation were underwent percutaneous endoscopic lumbar discectomy. The patients were divided into guide and control group, and 20 patients in each group. In guide group, there were 9 males and 11 females with an average age of (46.0±11.0) years old;5 patients on L3,4, 15 patients on L4,5; BMI was (25.4±3.2) kg /m2;three dimensional foramen guide was used to assist the operation. While in control group, there were 10 males and 10 females with an average age of (51.8±9.8) years old;4 patients on L3,4, 16 patients on L4,5;BMI was (24.8±3.5) kg /m2;the operation was completed with bare hands according to the experience. The puncture time, times of fluoroscopy and puncture between two groups were compared, as well as the preoperative and postoperative visual analogue scale (VAS) score and Japanese Orthopaedic Association (JOA) were compared. RESULTS: All patients had no serious complications, and successfully completed operation. Operation time, the times of fluoroscopy and puncture in guide group were better than those of control group (P<0.05). VAS score and JOA score between two groups were significantly relieved after operation (P<0.05), but there was no significant difference between two groups (P>0.05). CONCLUSION: The three dimensional foramen guide is compact in structure, simple in operation, which could reduce the time of puncture and damage of radiation, shorten the learning curve of puncture for beginners, and has certain clinical feasibility.

Intravenous administration of tranexamic acid in total hip arthroplasty does not change the blood coagulopathy: a prospective thrombelastography analysis.

OBJECTIVE: Despite the wide use of tranexamic acid (TXA) in the perioperative period of total hip arthroplasty (THA), whether the hemostatic state changes after the application of intravenous (IV)-TXA are still unknown. The aim of this study was to investigate whether IV administration of TXA changes the blood coagulation following primary THA via thrombelastography (TEG) analysis and conventional laboratory tests. METHODS: A total of 174 patients who underwent primary THA from September 2016 to July 2018 were selected. They were randomly divided into two groups, 86 patients with IV administration of 15 mg/kg TXA and 88 controls without TXA usage. Demographic data, TEG paremeters, d-dimer levels, fibrin degradation products, hemoglobin, hematocrit concentration, platelet, transfusion rates, perioperative blood loss, and the occurrence of deep vein thrombosis were collected. TEG and conventional laboratory tests were performed the day before operation, the first day after operation, and seventh day after operation. RESULTS: There were no differences with regard to TEG or conventional laboratory tests between the two groups (p > 0.05). The total blood loss and drain blood loss in the TXA group were significantly lower than those in the control group (p < 0.05). The transfusion rates and the volume of blood transfusion of the control group were higher than those of the TXA group (p < 0.05). CONCLUSION: The administration of IV-TXA resulted in a significant reduction in total blood loss, transfusion volumes, and transfusion rates without the increase of thromboembolic complications. Moreover, it was confirmed that TXA would not change the coagulation via the TEG analysis.

Pigment Epithelium-Derived Factor (PEDF) Protects Osteoblastic Cell Line from Glucocorticoid-Induced Apoptosis via PEDF-R.

Pigment epithelial-derived factor (PEDF) is known as a widely expressed multifunctional secreted glycoprotein whose biological actions are cell-type dependent. Recent studies demonstrated that PEDF displays cytoprotective activity in several cell types. However, it remains unknown whether PEDF is involved in glucocorticoid-induced osteoblast death. The aim of this study was to examine the role of PEDF in osteoblast survival in response to dexamethasone, an active glucocorticoid analogue, and explore the underlying mechanism. In the present study, dexamethasone (DEX) was used to induce MC3T3-E1 pre-osteoblast apoptosis. PEDF mRNA and protein levels and cell apoptosis were determined respectively. Then PEDF receptor (PEDF-R)- and lysophosphatidic acid (LPA)-related signal transductions were assessed. Here we show that DEX down-regulates PEDF expression, which contributes to osteoblast apoptosis. As a result, exogenous recombinant PEDF (rPEDF) inhibited DEX-induced cell apoptosis. We confirmed that PEDF-R was expressed on MC3T3-E1 pre-osteoblast membrane and could bind to PEDF which increased the level of LPA and activated the phosphorylation of Akt. Our results suggest that PEDF attenuated DEX-induced apoptosis in MC3T3-E1 pre-osteoblasts through LPA-dependent Akt activation via PEDF-R.