Objectives Neurological deficit (ND) following total aortic arch replacement (TAAR) carries high morbidity and mortality, and effective treatments are lacking. Intraoperative neuromonitoring is crucial in preventing ND. This cohort study aims to investigate the prognostic value of noninvasive electrical impedance tomography (EIT) for detecting ND after TAAR. Methods In this study, a 16 electrode EIT system was applied to monitor patients' brain impedance during TAAR. Six EIT parameters regarding to the hypothermic circulatory arrest (HCA) phase were extracted. The correlation between changes in EIT parameters and ND were fully explored. Results The incidence of ND was 39.1% (59/151), of which stroke was 15.2% (19/125). The time integral of absolute value resistivity asymmetric index (TRAI HCA ), the maximum value of the absolute resistivity asymmetric ratio (MRAR HCA ), age, body mass index, supra-aortic branch vessel involvement and operation time were independent predictors of ND. The incorporation of EIT parameters into the clinical model resulted in a notable enhancement in area under the receiver operating characteristic curve from 0.752 to 0.817 (P = 0.027). Furthermore, the incremental value of EIT parameters was also reflected in the improvement of risk reclassification and discrimination for ND(net reclassification index = 0.510, P = 0.002; integrated discrimination improvement = 0.072, P < 0.001). Conclusions The EIT parameters have been demonstrated to be an effective means of predicting ND following TAAR. Cerebral EIT may represent a potential alternative for intraoperative noninvasive multimodal neuromonitoring options. The findings of this study require further validation in further research.

Background This study aimed to estimate the influence of continuous and cluster nursing on carpal tunnel syndrome (CTS) release surgery. Methods Ninety-six patients with CTS were treated in our hospital from November 2019 to December 2021. These patients were randomly divided into two groups of 48 patients. Both groups underwent open carpal tunnel release surgery. The control group received routine nursing care, while the study group received a combination of continuous and cluster nursing interventions. The Boston carpal tunnel question, the Visual Analogue Scale (VAS), the Numerical Rating Scale (NRS), the Pittsburgh Sleep Quality Index (PSQI), Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH) and the Barthel index were used to compare hand function recovery, hand pain, sleep quality, and quality of life between the two groups before and 3 months after surgery. Results Both groups experienced improvements in hand function and pain 3 months after surgery. However, the study group demonstrated lower scores in symptom and dysfunction, as well as lower VAS and NRS scores compared to the control group (P < 0.05). Additionally, both groups showed an increase in the Barthel and PSQI scores 3 months after surgery. Notably, the study group exhibited higher Barthel scores and lower PSQI scores than the control group (P < 0.05). Conclusion The use of continuous and cluster nursing in patients undergoing CTS release surgery proves to be advantageous in alleviating hand pain, facilitating hand function recovery, and effectively enhancing sleep quality and overall quality of life for patients.

BACKGROUND: Significant regional disparities exist in implementing minimally invasive congenital heart disease (CHD) clinical pathways across China, leading to inefficient resource utilization and increased healthcare costs. METHODS: Using the Sino-CHD registry (n = 7001 patients from 13 centers), we applied a novel four-domain health economics evaluation framework to assess: (1) medical efficiency (hospitalization duration, intensive care unit stay, and same-day discharge [SDD] rates); (2) treatment-related metrics (surgical duration and transfusion rates); (3) medical quality metrics (mortality and complications); and (4) medical cost (material/drug expenditures). Comparative analyses examined interventional procedures (n = 4677) versus open surgical (n = 2324) approaches for atrial/ventricular septal defects and patent ductus arteriosus. RESULTS: Critical disparities emerged that Interventional cohorts demonstrated 20% SDD rates (range: 0%–99.5%), inversely correlating with hospitalization duration (P < 0.001). Surgical duration varied nearly 4-fold (24.7–86.5 min), while material costs drove 51%–80% of total expenditures (25,979 CNY–40,929 CNY). Open surgery cohorts exhibited 3-fold variation in transfusion rates (0%–75%) and major complications (0%–5.3%). Material costs constituted 55%–74% of total expenses (29,656 CNY–49,097 CNY). Visual analytics revealed preoperative testing completion and SDD adoption as primary modulators of hospitalization duration. CONCLUSIONS: This validated framework quantifies actionable pathway implementation gaps, highlighting cost-containment opportunities through standardized preoperative workflows, blood conservation protocols, and value-based device selection. The system enables targeted quality improvement in the resource-limited settings.

Cannulated screw fixation is a frequently utilized surgical procedure for the care of femoral neck fractures. During this procedure, TiRobot has demonstrated high surgical precision. However, whether TiRobot-assisted cannulated screw insertion is superior to traditional manual insertion remains controversial. As a result, we undertook a meta-analysis to determine the clinical impact of TiRobot in managing femoral neck fractures. We methodically searched PubMed, Embase, Scopus, Web of Science, and the Cochrane Library to find studies comparing TiRobot-assisted cannulated screw insertion with traditional manual insertion. The extracted data included demographics, fracture classification, and clinical outcomes. A total of six studies satisfied the inclusion criteria. Compared to traditional manual techniques, TiRobot demonstrated significant advantages in surgical time, intraoperative blood loss, hospital stay, fluoroscopy frequency, guide pin adjustments, and Harris hip score (WMD > 0). It also showed significant benefits in complications such as nonunion and femoral head necrosis (OR < 1). Overall, TiRobot technology demonstrated high safety and efficacy. However, additional high-quality randomized controlled trials are essential to substantiate the results of this study.

Sivelestat may reduce postoperative pulmonary injury after total arch replacement (TAR). This study aimed to evaluate whether the preoperative PaO2/FiO2 (P/F) ratio affects the efficacy of sivelestat in reducing postoperative pulmonary injury in patients with acute aortic dissection (AAD) who underwent TAR using deep hypothermic circulatory arrest (DHCA). Data of patients with AAD who underwent TAR using DHCA in a tertiary hospital between February 1, 2022, and December 30, 2022, were retrospectively reviewed. The patients were divided into the sivelestat and control groups. Three subgroup analyses were performed based on the postoperative P/F ratio. The primary clinical outcomes were assessed to determine the efficacy and safety of sivelestat in managing postoperative pulmonary dysfunction in patients undergoing cardiopulmonary bypass. A total of 187 patients were included, with 95 in the sivelestat group and 92 in the control group. No significant differences were found in the clinical variables between the two groups (all P > 0.05), except for some improvements in the inflammatory biomarker levels (including white blood cell count, neutrophil count, and C-reactive protein). Subgroup analysis revealed that sivelestat treatment significantly increased the P/F ratio on the 4th day and 3rd day after TAR in patients with mild lung injury (P = 0.02) and moderate lung injury (P = 0.03), respectively. Additionally, sivelestat reduced the levels of several postoperative inflammatory biomarkers in both subgroups. Among patients with AAD with mild or moderate preoperative lung injury, defined by a low P/F ratio, sivelestat significantly improved the postoperative P/F ratio and attenuated inflammatory responses after TAR. These findings suggest an important avenue for further research.

Injectable carbonated hydroxyapatite (ICHA) cement was developed by adding 2% Hydroxypropyl methylcellulose (HPMC) to carbonated hydroxyapatite (CHA) cement, improving its rheological properties and injectability for minimally invasive orthopedic use. The cement's physical and chemical properties, including curing time, strength, porosity, and consistency, were tested in vitro. Scanning electron microscopy, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to analyze the cured cement. Bone marrow stromal cells were cultured with ICHA cement extracts and specimens to test cell growth (MTT assay) and cytotoxicity. In vivo, the cement was implanted into rabbit muscles to assess inflammation and capsule formation, along with other biocompatibility tests, including hemolysis and pyrogen testing. ICHA cement sets without heat generation, with a 9-min initial setting time and a 15-min final setting time, similar to CHA cement. The strength reaches 20 MPa after 1 day and peaks at 35 MPa after 7 days. Its porosity is slightly higher than CHA cement, and it resists dilution well, preventing disintegration in water. The consistency of ICHA cement is lower than CHA cement at different time points (p < 0.001), showing a logarithmic change pattern. With adjustable setting time, good resistance to dilution, and compressive strength similar to cancellous bone, ICHA cement is well suited for clinical use. Its composition closely resembles natural bone, offering strong fixation and stability for tibial plateau healing, which supports early movement and reduces the risk of joint stiffness and post-traumatic arthritis.

In the current study, we investigated the effects of acteoside as a phenylpropanoid glycoside on interaction with neurons to assesses locomotor recovery after spinal cord injury (SCI) in rats by focusing on evaluating the factors involved in autophagy, apoptosis, inflammation and oxidative stress processes. 49 Spargue-Dawley rats were prepared and divided into seven healthy and SCI groups receiving different concentrations of acteoside. After 28 days of disease induction and treatment with acteoside, a BBB score test was used to evaluate locomotor activity. Then, by preparing spinal cord cell homogenates, the expression levels of MAP1LC3A, MAP-2, glial fibrillary acidic protein (GFAP), Nrf2, Keap-1, Caspase 3 (Casp3), Bax, Bcl-2, TNF-a, IL-1B, reactive oxygen species (ROS), and malondialdehyde (MDA) were measured. Improvement of locomotor activity in SCI rats receiving acteoside was observed two weeks after the beginning of the experiment and continued until the fourth week. Both MAP1LC3A and MAP-2 were significantly up-regulated in SCI rats treated with acteoside compared to untreated SCI rats, and GFAP levels were significantly decreased in these animals. Pro-apoptotic proteins Bax and Casp3 and anti-apoptotic protein Bcl-2 were down-regulated and up-regulated, respectively, in SCI rats receiving acteoside. In addition, a significant downregulation of iNOS, TNF-alpha, and IL-1 beta and a decrease in contents of both ROS and MDA as well as increases in Nrf2 and Keap-1 were seen in rats receiving acteoside. Furthermore, acteoside strongly interacted with MAP1LC3A, TNF-alpha, and Casp3 targets with binding affinities of -8.3 kcal/ mol, -8.3 kcal/mol, and -8.5 kcal/mol, respectively, determined by molecular docking studies. In general, it can be concluded that acteoside has protective effects in SCI and can be considered as an adjuvant therapy in the treatment of this disease. However, more studies, especially clinical studies, are needed in this field.

Abstract Postoperative neurological dysfunction (PND) is one of the most common complications after a total aortic arch replacement (TAAR). Electrical impedance tomography (EIT) monitoring of cerebral hypoxia injury during TAAR is a promising technique for preventing the occurrence of PND. This study aimed to explore the feasibility of electrical impedance tomography (EIT) for warning of potential brain injury during total aortic arch replacement (TAAR) through building the correlation between EIT extracted parameters and variation of neurological biomarkers in serum. Patients with Stanford type A aortic dissection and requiring TAAR who were admitted between December 2021 to March 2022 were included. A 16-electrode EIT system was adopted to monitor each patient’s cerebral impedance intraoperatively. Five parameters of EIT signals regarding to the hypothermic circulatory arrest (HCA) period were extracted. Meanwhile, concentration of four neurological biomarkers in serum were measured regarding to time before and right after surgery, 12 h, 24 h and 48 h after surgery. The correlation between EIT parameters and variation of serum biomarkers were analyzed. A total of 57 TAAR patients were recruited. The correlation between EIT parameters and variation of biomarkers were stronger for patients with postoperative neurological dysfunction (PND(+)) than those without postoperative neurological dysfunction (PND(−)) in general. Particularly, variation of S100B after surgery had significantly moderate correlation with two parameters regarding to the difference of impedance between left and right brain which were MRAIabs and TRAIabs (0.500 and 0.485 with p < 0.05, respectively). In addition, significantly strong correlations were seen between variation of S100B at 24 h and the difference of average resistivity value before and after HCA phase (ΔARVHCA), the slope of electrical impedance during HCA (kHCA) and MRAIabs (0.758, 0.758 and 0.743 with p < 0.05, respectively) for patients with abnormal S100B level before surgery. Strong correlations were seen between variation of TAU after surgery and ΔARVHCA, kHCA and the time integral of electrical impedance for half flow of perfusion (TARVHP) (0.770, 0.794 and 0.818 with p < 0.01, respectively) for patients with abnormal TAU level before surgery. Another two significantly moderate correlations were found between TRAIabs and variation of GFAP at 12 h and 24 h (0.521 and 0.521 with p < 0.05, respectively) for patients with a normal GFAP serum level before surgery. The correlations between EIT parameters and serum level of neurological biomarkers were significant in patients with PND, especially for MRAIabs and TRAIabs, indicating that EIT may become a powerful assistant for providing a real-time warning of brain injury during TAAR from physiological perspective and useful guidance for intensive care units.

Background This study was designed to explore factors associated with the incidence of positive bacterial culture of salvaged red blood cells (sRBCs) recovered with a Cell Saver instrument during cardiac surgery and the impact of such positive outcomes on postoperative infection-related morbidity. Methods The cohort study enrolled 204 patients scheduled for cardiac surgery with intraoperative blood cell salvage and retransfusion from July 2021 to July 2022. These patients were stratified into two groups based on intraoperative sRBCs bacterial culture results: culture (+) and culture (−) groups. Preoperative and intraoperative variables were compared between these groups aim to detect possible predictors of positive culture in sRBCs. In addition, differences in postoperative infection-related morbidity and other clinical outcomes were compared between these groups. Results Of these patients, 49% were sRBCs culture (+), with Staphylococcus epidermidis as the most commonly identified pathogen. Risk factors independently associated with the risk of positive culture in sRBCs included BMI ≥25 kg/m2, a history of smoking, an operative duration ≥277.5 min, the higher number of staff in the operating room and higher surgical case order. Patients in the sRBCs culture (+) group exhibited a longer average ICU stay [3.5 days (2.0–6.0) vs. 2 days (1.0–4.0), P < 0.01], a longer duration of ventilation [20.45 h (12.0–17.8) vs. 13 h (11.0–17.0, P = 0.02)], underwent more allogeneic blood transfusions, exhibited higher transfusion-related costs [2,962 (1,683.0–5,608.8) vs. 2,525 (1,532.3–3,595.0), P = 0.01], and had higher rates of postoperative infections (22 vs. 9.6%, P = 0.02) as compared to patients in the sRBCs culture (−) group. In addition, culture (+) in sRBCs was an independent risk factor for postoperative infection (OR 2.62, 95% CI 1.16–5.90, P = 0.02). Conclusion Staphylococcus epidermidis was the most common pathogen detected in sRBCs in the culture (+) group in this study, identifying it as a potential driver of postoperative infection. Positive sRBCs culture may contribute to postoperative infection and its incidence was significantly associated with patient BMI, history of smoking, operative duration, the number of staff in the operating room and surgical case order.

The purpose of this study was to evaluate the clinical efficacy of internal fixation with locking compression plates (LCP) in the treatment of patients with extremity fractures and the effect on the recovery of limb function. A total of 488 patients with extremity fractures admitted to our hospital from June 2019 to December 2022 were retrospectively analyzed and divided into open reduction and internal fixation (ORIF) group (n = 236) and internal fixation with LCP group (n = 252) according to the surgical procedure. Outcome indicators included intraoperative bleeding, operative time, length of hospital stay, pain duration, quality of life, healing time of the fracture, postoperative complications, and restoration of limb function as per the X-ray examination results and Johner-Wruhs criteria. Self-rating Depression Scale and Self-rating Anxiety Scale were used to evaluate the changes of patients' negative emotions before and after treatment. LCP group was associated with significantly less intraoperative bleeding and shorter operative time, length of hospital stays, and pain duration compared with ORIF group (P < .05). Compared with ORIF group, LCP group provided more rapid fracture healing in tibial fractures, ulnar fractures, radial fractures, and external ankle fractures (P < .05). Compared with the ORIF group, patients in the LCP group showed better quality of life in terms of physical, psychological and social functions after surgery (P < .05). The incidence of postoperative complications in the LCP group was significantly lower than that in the ORIF group (19.92% vs 7.14%, P < .001). The Self-rating Depression Scale and Self-rating Anxiety Scale scores of the LCP group were lower than those of the ORIF group (P < .05). The recovery of limb function was significantly better in the LCP group than in the ORIF group (97.22% vs 85.17%, P < .001). The overall satisfaction rate of treatment in the LCP group was higher than that in the ORIF group (92.06% vs 81.90%, P < .001). Internal fixation with LCP in patients with extremity fractures can effectively promote the recovery of limb function, reduce the incidence of complications and improve the quality of life of patients.

BackgroundThe correlation between rhabdomyolysis and postoperative acute kidney injury has been reported in several surgical procedures. As a good predictor of rhabdomyolysis-related acute kidney injury, an elevated serum myoglobin level was often observed after total aortic arch replacement combined with frozen elephant trunk implantation. However, the correlation between serum myoglobin and acute kidney injury in such patients had not been established.MethodsTotally 398 stanford type A aortic dissection patients who underwent total aortic arch replacement combined with frozen elephant trunk implantation were enrolled in this retrospective study. The correlations between serum myoglobin and acute kidney injury as well as the 30-day mortality were assessed.ResultsOverall, 268(67.3%) patients had acute kidney injury (KDIGO stage 1 or higher) and 75(18.8%) had severe acute kidney injury (KDIGO stage 2&3). Patients who developed acute kidney injury had higher level of perioperative serum myoglobin than patients without acute kidney injury. After adjusting for known acute kidney injury risk factors, logarithmically transformed preoperative serum myoglobin [OR = 1.58 (95% CI, 1.26–1.95), P < 0.001] and postoperative day 1 serum myoglobin [OR = 3.47 (95%CI, 2.27–5.29), P < 0.001] were associated with severe acute kidney injury. These correlation persisted after adjustment for decline in filtration via change in serum creatinine (ΔCr) and biomarkers of cardiac and kidney injury, including N-terminal prohormone of brain natriuretic peptide, cardiac troponin I, creatine kinase-MB, serum creatinine and Cystatin C. Compared with the clinical model, sMb considerably improved the risk discrimination and reclassification for AKI.ConclusionFor stanford type A aortic dissection patients underwent total aortic arch replacement with frozen elephant trunk implantation, serum myoglobin can improve postoperative acute kidney injury risk classification. Rhabdomyolysis may be an important supplement to the existing knowledge on the mechanism of acute kidney injury.

Objective This study aimed to investigate the value of a horizontal rafting plate in treating tibial plateau fractures. Methods The data of 24 patients in whom a horizontal rafting plate was used to treat a tibial plateau fracture between October 2014 and January 2018 were retrospectively analyzed, including 16 males and 8 females, aged 21–63 years old, with an average of 40 ± 14.68 years. The fractures included 13 in the left knee and 11 in the right knee. The places where the horizontal rafting plate were used included the anterior margin of tibia, anterolateral tibia, and posterolateral tibia. All cases were followed up for 12–24 months, with an average follow‐up of 17.5 ± 5.0 months. At the last follow‐up, the Rasmussen radiological criteria were used to evaluate the effect of fracture reduction and fixation. The knee joint function was evaluated using the Rasmussen functional score. Computed tomography (CT) scanning and three‐dimensional reconstruction were performed preoperatively and postoperatively, with the quality of reduction of the fractured articular surface clarified by the final follow‐up. The flexion and extension abilities of the knee joint were also measured in the postoperative follow‐up. Results Preoperative CT scanning showed that the gap of the tibial plateau was 8.00 ± 1.40 (5–24) mm. The heights of the fracture of the articular surface at all three sites during the final follow‐ups were significantly different from the height before the surgery ( P < 0.05). The vertical distance between the articular line and the highest point of the articular surface after reduction was 0.17 ± 0.05 mm. Anatomic reductions were obtained in 24 patients. The Rasmussen functional score after surgeries was 27.25 ± 0.94 points. Bony union was achieved in all the patients. According to the Rasmussen radiological criteria, the scores during the last follow‐up were as follows: the total score was 13–18 points, with an average of 16.00 ± 1.72 points; the scores were excellent in 17 cases and good in seven cases. Therefore, 100% of results were excellent or good. No infection or fracture nonunion was found. Conclusion Using a horizontal plate can be an effective method for treating special types of fractures of the tibial plateau, including the anterior margin and anterolateral and posterolateral tibial plateau, with satisfactory treatment efficacy.

Clavicle fractures may occur in all age groups, and 70%-80% of clavicle fractures occur in the midshaft. Many methods for treating midshaft clavicular fractures have been reported and remain controversial. To provide some guidance for clinical treatment, 30 artificial polymethyl methacrylate models of the clavicle were sewn obliquely at the midshaft to simulate the most common type of clavicular fractures, and the fracture models were divided into five groups randomly and were fixed as follows: the reconstruction plates were placed at the superior position of the fracture model (R-S group), the reconstruction plates were placed at the anteroinferior position of the fracture model (R-AI group), the locking plates were placed at the superior position (L-S group), the locking plates were placed at the anteroinferior position (L-AI group); and the control models were unfixed (control group). The strain gauges were attached to the bone surface near the fracture fragments, and then, the biomechanical properties of the specimens were measured using the compression test, torsion test and three-point bending test. The results showed that plate fixation can provide a stable construct to help with fracture healing and is the preferred method in the treatment of clavicle fractures. The locking plate provides the best biomechanical stability when placed at the anteroinferior position, and this surgical method can reduce the operation time and postoperative complications; thus, it would be a better choice in clinical practice.

Subtrochanteric fractures are common and result in significant morbidity and mortality. Various kinds of implants have been used to fix it. The aim of this study was to compare the biomechanical performance of PFN, DHS, DCS, and the PFLP in the treatment of subtrochanteric comminuted fractures.A total of 32 antiseptic human femurs from 16 donors were randomly allocated to 4 groups for fixation with PFN, DHS, DCS, and PFLP. A 2-cm cylindrical bone fragment was removed 1cm below the lesser trochanter to simulate OTA/AO 32-C3.2 post instrumentation fracture. All specimens in single-leg stance situation were preloaded 5 times at 100N in the axial direction to eliminate the time effect of relaxation and settling, followed by cyclic testing at a rate of 1Hz with stepwise increasing load. Keeping the valley load at a constant level of 100N during the entire cyclic test, the peak load, starting at 200N, was increased by 100N at 300-cycle steps until a maximum of 1500 cycles or until failure of the bone-implant construct occurred. Each specimen was kept unloaded under 100N compression for 30 minutes between the 300-cycle steps.Femoral head displacement after 1500 cycles was 1.09mm0.13 for PFN, 1.78mm +/- 0.25 for DHS, 2.63mm +/- 0.46 for DCS, and 2.26mm +/- 0.16 for PFLP, with significant difference between any 2 implants (P<0.01). The required load to reach 1-mm femoral head displacement was 563.04N +/- 158.34 for PFN, 485.73N +/- 147.27 for DHS, 258.44N +/- 97.23 for DCS, and 332.68N +/- 100.34 for PFLP. Significant differences were detected between any 2 implants (P<0.001), except between DCS and PFLP and between DHS and PFN. The number of cycles until 1-mm femoral head displacement was 1458 +/- 277 for PFN, 908 +/- 184 for DHS, 369 +/- 116 for DCS, and 603 +/- 162 for PFLP. Significant differences were detected between any 2 implants (P<0.01), except between DCS and PFLP.From biomechanical point of view, comminuted subtrochanteric fractures OTA/AO 32-C3.2 revealed in the current test setup highest fixation strength with PFN, followed by DHS, PFLP, and DCS.

Objective To compare the effect of different preservation methods on the biomechanical properties of rat Achilles tendons,and recommend the best tendon preservation method.Methods Achilles tendons from 25 SD rats were randomly divided into 5 groups:fresh,-20℃ preservation,-80℃ preservation,liquid nitrogen preservation and 10％ formalin preservation group.Tendons in the fresh group were set out for biomechanical test immediately after dissection.Tendons in the rest four groups were preserved accordingly before being subject to biomechanical tests.The length and width of the tendons were measured to calculate the cross sectional areas.After preloading,the tendon was straightened and the initial length was recorded.The tendon was then stretched at a rate of 3 mm/min until the middle position of the tendon ruptured.The load and displacement were recorded,and the maximum strain,maximum stress and stiffness of tendons were calculated.Results There were no significant differences of the initial length of the tendons (F =0.217,P =0.921).The cross sectional areas of tendons in the cryopreservation groups increased,while the ones in the formalin preservation group decreased.These differences were significant (P ＜ 0.05).The maximum tensile length,maximum strain and maximum stress of the preserved groups were lower when compared to those of the fresh group,the differences being significant for liquid nitrogen preservation group and formalin preservation group (P＜0.05).Tendon stiffness in-20℃ group and-80℃ group was higher,compared to the fresh group (P ＜ 0.05).Tendon stiffness in the liquid nitrogen group and formalin group was lower than that in the fresh group,the difference being significant (P ＜ 0.05).Conclusion Comparing to liquid nitrogen group and 10％ formalin group,the biomechanical properties of tendons in-20℃ group and-80℃ group were closer to those of fresh tendons.Cryopreservation is the recommended method for tendon preservation.

OBJECTIVE:To evaluate the influence of nicotine intake on bone microstructure, bone biomechanics, and oxidative stress state in rats.METHODS:Thirty-six 6-week-old male Sprague Dawley rats (weight, 160-180 g) were randomly divided into control group, low dose group, and high dose group, 12 rats each group. The rats in high dose group and low dose group were given respectively 6.0 mg/kg and 0.4 mg/kg nicotine gavage intervention for 12 months; no intervention was made in the control group. The survival of rats was observed during experiment, and the weight of rats was measured every month. At 12 months after modeling, the L1 vertebral body was harvested to measure the bone mineral density (BMD), bone volume fraction (BVF), trabecular thickness (TT), trabecular number (TN), and trabecular spacing (TS) by Micro-CT three-dimensional reconstruction; the left femur was harvested for biomechanical tests of maximal load, stiffness, and the maximal fracture energy; and arterial blood was extracted to measure the malonyldialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and cotinine.RESULTS:During the experiment, two rats and one rat were added in the high dose group and the low dose group because of death, and no death in the control group. The body weight of the rats in the high and low dose groups gradually decreased with time when compared with one in the control group, and significant difference was found between two dose groups and the control group at 8-12 months (P<0.05); the body weight of the high dose group was significantly lower than that of the low dose group at 11 and 12 months (P<0.05). At 12 months after modeling, BMD, BVF, TT, and TN were significantly lower in the high dose group than the control group and the low dose group, but TS was significantly increased (P<0.05). Difference in BVF, TN, and TS was significant between the low dose group and the control group (P<0.05). The maximal load, stiffness, and maximal fracture energy of femoral shaft were significantly lower in the high dose group than the control group and the low dose group, and in the low dose group than the control group (P<0.05). Compared with the control group, the levels of cotinine and MDA were significantly increased, and the levels of CAT and SOD were significantly decreased in the high and low dose groups (P<0.05), and there were significant differences between the high and low dose groups (P<0.05).CONCLUSIONS:Nicotine intake can cause micro-structural changes of the bone, decreased bone mechanical properties, and imbalance of oxidation-antioxidant levels in rats. High-dose nicotine intake may be one of the causes of osteoporosis.

Spinal fusion surgery has been widely applied in clinical treatment, and the spinal fusion rate has improved markedly. However, its postoperative complications, especially adjacent segment degeneration, have increasingly attracted the attention of spinal surgeons. The most common pathological condition at adjacent segments is hypertrophic degenerative arthritis of the facet joint. To study the stress distribution changes at the adjacent facet joint after lumbar fusion with pedicle screw fixation, human cadaver lumbar spines were used in the present study, and electrical resistance strain gauges were attached on L1-L4 articular processes parallel or perpendicular to the articular surface of facet joints. Subsequently, electrical resistance strain gauge data were measured using anYJ-33 static resistance strain indicator with three types of models: the intact model, the laminectomy model, and the fusion model with pedicle screw fixation. The strain changes in the measurement sites indirectly reflect the stress changes. Significant differences in strain were observed between the normal and laminectomy state at all facet joints. Significant differences in strain were observed between the normal and the pedicle screw fixation fusion state at the L1/2 and L3/4 facet joints. The increased stress on the facet joints after lumbar fusion with pedicle screw fixation may be the cause of adjacent segment degeneration.

OBJECTIVE:To compare the biomechanical properties of four types of internal fixation (proximal femoral nail [PFN], dynamic hip screw [DHS], dynamic condylar screw [DCS], and proximal femoral locking plate [PFLP]) for different types of subtrochanteric fractures.METHODS:Thirty-two antiseptic femurs were randomly divided into four groups. After internal fixation had been implanted, different types of subtrochanteric fracture models were produced and each tested under vertical, torsional and vertical damage loads.RESULTS:The stiffness ratio of PFN in each fracture model and failure load were the highest in the four groups; however, the torsional stiffness ratio was the lowest. Tension strain ratios of DHS and DCS on the lateral side became compression strain ratios with restoration of the medial fragment. The stiffness ratio of DHS was lower than PFLP in each fracture model, torsional stiffness ratio was the highest in fracture models II to V and the failure load was lower only than PFN. The stiffness ratio and failure load of DCS were both the lowest, torsional stiffness ratio was similar to PFLP's in fracture models II to V. The stiffness ratio of PFLP was only lower than PFN's in each fracture model, but the failure load was lower than DHS's.CONCLUSION:Four types of internal fixation achieve better stabilities for type I subtrochanteric fractures. PFN and PFLP produce reliable stability in type IIIA subtrochanteric fractures. If the medial buttress is restored, DCS can be considered. For type IV subtrochanteric fractures, only PFN provides stable fixation. PFLP is suitable for comminuted fractures with large fragments.

BACKGROUND:Intraarticular steroid injections are widely used in joint arthritis. However, the data regarding an association between an increased risk for arthroplasty infection after an intraarticular steroid injection are still conflicting. We conducted a meta-analysis to evaluate the evidence from relevant studies that examine the relation between intraarticular steroid injections and infection rates in subsequent joint arthroplasty and to develop GRADE based recommendations for using the steroid before arthroplasty.METHODS:A systematic search of all studies published through August 2014 was conducted using the MEDLINE, EMBASE, OVID, ScienceDirect and Cochrane CENTRAL databases. The relevant studies that examined the relation between intraarticular steroid injections and infection rates in subsequent joint arthroplasty were identified. Demographic characteristics, infection rates and clinical outcomes were manually extracted from all of the selected studies. The evidence quality levels and recommendations were assessed using the GRADE system.RESULTS:Eight studies looking at hip and knee arthroplasties were included. Meta-analysis showed that patients with steroid injection before arthroplasty had a higher deep infection rate than patients without steroid injection (OR = 2.13, 95% CI 1.02-4.45), but no significant effect on superficial infection rate (OR = 1.75, 95% CI 0.74-4.16). The overall GRADE system evidence quality was very low, which lowers our confidence in their recommendations.CONCLUSIONS:Intraarticular steroid injections may lead to increased deep infection rates of subsequent joint arthroplasty but not the superficial infection rates. Due to the poor quality of the evidence currently available, further studies are still required.

In Brief Study Design. Methodological systematic review. Objective. To identify the risk factors for new vertebral compression fractures (VCFs) in patients after percutaneous vertebroplasty (PVP) and to grade the evidence according to the quality of included studies. Summary of Background Data. PVP is an effective procedure for the treatment of VCFs. A major concern after PVP in patients with osteoporosis is the occurrence of new VCFs in the untreated vertebrae. The risk factors for new VCFs after PVP reported thus far remain controversial. These risk factors have neither been well identified or summarized. This systematic review was performed to identify the risk factors for new VCFs after PVP. Methods. Noninterventional studies evaluating the risk factors for new VCFs of patients with osteoporosis after PVP were searched in MEDLINE, EMBASE, ScienceDirect, and OVID databases (all up to November 2012). Only observational studies with eligible data were included. Quality of included studies was assessed by a modified quality assessment tool, which was previously designed for observational study. The effects of studies were combined with the study quality score using a model of best-evidence synthesis. Results. Twenty-four observational studies involving 3789 patients were included. These articles were published between 2004 and 2012. According to the quality assessment criteria for included studies, 8 studies were deemed as high-quality studies, 6 as moderate-quality studies, and 10 as low-quality studies. There were strong evidences of 3 risk factors, including lower bone mineral density, lower body mass index, intradiscal cement leakage, and vertebral height restoration. We also identified 6 moderate-evidence factors including lower body mass index, number of pre-existing vertebral fractures, thoracolumbar junction in initial VCFs, cement distraction, older age, and number of treated vertebrae. Thirteen factors were classified into the limited-evidence risk factors. Conclusion. Although there is no conclusive evidence for new VCFs of patients with osteoporosis after PVP procedure, these data provide evidence to guide the surgeon and develop optimal preventions for new VCFs after PVP. Special attention should be paid to the 3 strong-evidence risk factors. Further studies were still required to evaluate the effects of the earlier mentioned risk factors. Level of Evidence: 2 Risk factors for new vertebral compression fractures of patients after percutaneous vertebroplasty have neither been well identified or summarized. This systematic review have identified these risk factors based on the methodological quality of studies. It will provide evidence to guide the surgeon to develop optimal preventions.