Objective:To explore the safety and efficacy of intraosseous regional administration (IORA) of vancomycin for preventing infection in primary total knee arthroplasty (TKA).Methods:A total of 124 patients with knee osteoarthritis undergoing TKA between February 2024 and May 2024 at nine hospitals were enrolled. Preoperative infection prophylaxis involved either IORA (0.5 g vancomycin administered via intraosseous regional infusion before incision) or intravenous infusion (1 g vancomycin via peripheral vein). The IORA group included 15 males and 47 females with a median age of 66.5 years (range, 60.0-70.0 years), while the intravenous group included 14 males and 48 females with a median age of 66.0 years (range, 61.8-70.3 years) years. Intraoperative samples were collected including fat and synovium tissues after incision, before prosthesis placement, and after tourniquet release; distal femoral cancellous bone during femoral osteotomy; proximal tibial cancellous bone during tibial osteotomy; proximal intercondylar cancellous bone before prosthesis placement; and peripheral blood from non-infused arms at surgery initiation and after tourniquet release. Vancomycin concentrations were measured using liquid chromatography-tandem mass spectrometry. Vital sign changes were recorded from admission to 5~10 minutes post-IORA (IORA group) or post-incision (intravenous group). Follow-ups were conducted on postoperative day 1 and 3, and at 1 and 3 months, to document complications including IORA-related adverse events, periprosthetic joint infections, surgical site infections, red man syndrome, acute kidney injury, deep vein thrombosis and so on.Results:Vancomycin concentrations in bone, fat, and synovial tissue samples were significantly higher in the IORA group than in the intravenous group ( P<0.05), while vancomycin concentrations in blood samples were significantly lower in the IORA group than in the intravenous group ( P<0.05). Only 7.3%(41/558) of tissue samples in the IORA group had vancomycin concentrations below 2.0 μg/g (the minimum inhibitory concentration of vancomycin against coagulase-negative staphylococcus), compared to 59.3%(331/558) in the intravenous group (χ 2=11.285, P<0.001). In the intravenous group, 16.9%(21/124) of blood samples had vancomycin concentrations exceeding 15.0 mg/L (the threshold associated with a significantly increased risk of nephrotoxicity), while all concentrations in the IORA group were below this threshold, the difference was statistically significant (χ 2=22.943, P<0.001). There were no statistically significant difference ( P>0.05) in vital signs changes before and after vancomycin administration between the two groups. Two patients in the intravenous group experienced incision exudate, while no other related complications occurred in either group. Conclusions:Compared to the traditional intravenous infusion of 1 g vancomycin, intraosseous injection of a low dose (0.5 g) of vancomycin achieves higher local tissue concentrations in the knee joint with a lower incidence of adverse reactions and is safe for infection prophylaxis. Despite guidelines not recommending the routine use of vancomycin for preventing infection after primary TKA, intraosseous injection of 0.5 g vancomycin may be considered intraoperatively for primary TKA in the following scenarios: patients in medical institutions with a high prevalence of methicillin-resistant staphylococcus aureus (MRSA) infections, patients with potential preoperative MRSA colonization, or patients with cephalosporin allergy.

Objective:To establish a normal data model of fetal right ventricular size and function using echocardiography，and to explore the clinical value of quantitative assessment of right ventricular size and function in the diagnosis of congenital heart diseases.Methods:（1）A simple random sampling method was employed to collect 1 004 pregnant women with normal singleton pregnancies at 24 to 32 +6 weeks of gestation who underwent fetal cardiac ultrasound examinations at the First Affiliated Hospital of Air Force Medical University from January 2021 to December 2023. Two-dimensional and M-mode echocardiography were used to measure the right ventricular end-diastolic diameter（RVEDD），right ventricular end-diastolic area（RVEDA），tricuspid annular plane systolic excursion（TAPSE）during systole，and the right ventricular fractional area change（RVFAC）was calculated. The correlations between the above parameters and ultrasound gestational age（USGA）were analyzed. Moreover，percentile growth curves for each parameter were plotted. With the above parameters as dependent variables and the USGA as the independent variable，a Z-score model was established through regression analysis.（2）A stratified sampling method was adopted to select 30 fetuses diagnosed with hypoplastic right heart syndrome（HRHS）and 30 fetuses diagnosed with pulmonary stenosis（PS）during the same period as the case group. The model was verified，and the morphological and functional characteristics of the right ventricle were analyzed. Results:The data of RVEDD，RVEDA，TAPSE，and RVFAC in normal fetuses showed a skewed distribution. Each parameter showed good linear correlations with USGA（ r=0.836，0.834，0.846，0.242；all P<0.001）. The constructed percentile curves for each parameter indicated that RVEDD，RVEDA and TAPSE increased significantly with the growth of USGA，while RVFAC showed a slow downward trend. All parameters in the HRHS group and TAPSE and RVFAC in the PS group deviated significantly from the normal reference range（all P<0.001）. Conclusions:By analyzing RVEDD，RVEDA，TAPSE and RVFAC of normal fetuses，the percentile and Z-score normal reference value models of multiple parameters of fetal right ventricular size and function have been established，providing corresponding standards for quantitative analysis.

Objective:To explore the safety and efficacy of intraosseous regional administration (IORA) of vancomycin for preventing infection in primary total knee arthroplasty (TKA).Methods:A total of 124 patients with knee osteoarthritis undergoing TKA between February 2024 and May 2024 at nine hospitals were enrolled. Preoperative infection prophylaxis involved either IORA (0.5 g vancomycin administered via intraosseous regional infusion before incision) or intravenous infusion (1 g vancomycin via peripheral vein). The IORA group included 15 males and 47 females with a median age of 66.5 years (range, 60.0-70.0 years), while the intravenous group included 14 males and 48 females with a median age of 66.0 years (range, 61.8-70.3 years) years. Intraoperative samples were collected including fat and synovium tissues after incision, before prosthesis placement, and after tourniquet release; distal femoral cancellous bone during femoral osteotomy; proximal tibial cancellous bone during tibial osteotomy; proximal intercondylar cancellous bone before prosthesis placement; and peripheral blood from non-infused arms at surgery initiation and after tourniquet release. Vancomycin concentrations were measured using liquid chromatography-tandem mass spectrometry. Vital sign changes were recorded from admission to 5~10 minutes post-IORA (IORA group) or post-incision (intravenous group). Follow-ups were conducted on postoperative day 1 and 3, and at 1 and 3 months, to document complications including IORA-related adverse events, periprosthetic joint infections, surgical site infections, red man syndrome, acute kidney injury, deep vein thrombosis and so on.Results:Vancomycin concentrations in bone, fat, and synovial tissue samples were significantly higher in the IORA group than in the intravenous group ( P<0.05), while vancomycin concentrations in blood samples were significantly lower in the IORA group than in the intravenous group ( P<0.05). Only 7.3%(41/558) of tissue samples in the IORA group had vancomycin concentrations below 2.0 μg/g (the minimum inhibitory concentration of vancomycin against coagulase-negative staphylococcus), compared to 59.3%(331/558) in the intravenous group (χ 2=11.285, P<0.001). In the intravenous group, 16.9%(21/124) of blood samples had vancomycin concentrations exceeding 15.0 mg/L (the threshold associated with a significantly increased risk of nephrotoxicity), while all concentrations in the IORA group were below this threshold, the difference was statistically significant (χ 2=22.943, P<0.001). There were no statistically significant difference ( P>0.05) in vital signs changes before and after vancomycin administration between the two groups. Two patients in the intravenous group experienced incision exudate, while no other related complications occurred in either group. Conclusions:Compared to the traditional intravenous infusion of 1 g vancomycin, intraosseous injection of a low dose (0.5 g) of vancomycin achieves higher local tissue concentrations in the knee joint with a lower incidence of adverse reactions and is safe for infection prophylaxis. Despite guidelines not recommending the routine use of vancomycin for preventing infection after primary TKA, intraosseous injection of 0.5 g vancomycin may be considered intraoperatively for primary TKA in the following scenarios: patients in medical institutions with a high prevalence of methicillin-resistant staphylococcus aureus (MRSA) infections, patients with potential preoperative MRSA colonization, or patients with cephalosporin allergy.

Objective:To establish a normal data model of fetal right ventricular size and function using echocardiography，and to explore the clinical value of quantitative assessment of right ventricular size and function in the diagnosis of congenital heart diseases.Methods:（1）A simple random sampling method was employed to collect 1 004 pregnant women with normal singleton pregnancies at 24 to 32 +6 weeks of gestation who underwent fetal cardiac ultrasound examinations at the First Affiliated Hospital of Air Force Medical University from January 2021 to December 2023. Two-dimensional and M-mode echocardiography were used to measure the right ventricular end-diastolic diameter（RVEDD），right ventricular end-diastolic area（RVEDA），tricuspid annular plane systolic excursion（TAPSE）during systole，and the right ventricular fractional area change（RVFAC）was calculated. The correlations between the above parameters and ultrasound gestational age（USGA）were analyzed. Moreover，percentile growth curves for each parameter were plotted. With the above parameters as dependent variables and the USGA as the independent variable，a Z-score model was established through regression analysis.（2）A stratified sampling method was adopted to select 30 fetuses diagnosed with hypoplastic right heart syndrome（HRHS）and 30 fetuses diagnosed with pulmonary stenosis（PS）during the same period as the case group. The model was verified，and the morphological and functional characteristics of the right ventricle were analyzed. Results:The data of RVEDD，RVEDA，TAPSE，and RVFAC in normal fetuses showed a skewed distribution. Each parameter showed good linear correlations with USGA（ r=0.836，0.834，0.846，0.242；all P<0.001）. The constructed percentile curves for each parameter indicated that RVEDD，RVEDA and TAPSE increased significantly with the growth of USGA，while RVFAC showed a slow downward trend. All parameters in the HRHS group and TAPSE and RVFAC in the PS group deviated significantly from the normal reference range（all P<0.001）. Conclusions:By analyzing RVEDD，RVEDA，TAPSE and RVFAC of normal fetuses，the percentile and Z-score normal reference value models of multiple parameters of fetal right ventricular size and function have been established，providing corresponding standards for quantitative analysis.

Objective::To investigate the safety and efficacy of internal electronic fetal heart rate (FHR) monitoring during labor.Methods::This was a retrospective case-control study, which was an analysis of monitoring FHR with a fetal scalp electrode or a Doppler probe (94 pregnant women per group). In the internal monitoring group, when the opening of the uterine orifice was ≥3 cm, the fetal scalp electrode was placed after natural or artificial rupture of the membrane. FHR was simultaneously monitored using a Doppler probe. In the external monitoring group, continuous FHR monitoring was performed using an ultrasound Doppler transducer fixed on the maternal abdomen. The toco transducer was used to record uterine contractions. Pathological examination of the placenta was performed prospectively in 49 and 48 cases in the internal electronic FHR monitoring group and control group, respectively. Maternal-infant outcomes (e.g. fever, puerperal infection, puerperal morbidity, delivery mode, Apgar score, and scalp injury) were recorded. Umbilical artery blood was extracted for blood gas analysis. Differences between the two groups were compared using the paired t-test, χ2 test, Yates corrected χ2 test or Fisher exact test. Results::Non-statistically significant differences between the internal and external monitoring groups were observed in the incidence of neonatal acidosis (1/94 (1.06%) vs. 3/94 (3.19%), respectively; χ2= 0.255, P= 0.613), cesarean section/operative vaginal delivery (8/94 (8.51%) vs. 15/94 (15.96%), respectively; χ2 = 2.427, P= 0.181), fever during labor (18/94 (19.15%) vs. 15/94 (15.96%), respectively; χ2=0.331, P= 0.565), puerperal morbidity (2/94 (2.13%) vs. 3/94 (3.19%), respectively; χ2= 0.000, P= 1.000), chorioamnionitis (9/49 (18.37%) vs. 7/48(14.58%), respectively; χ2= 0.252, P= 0.616), and neonatal asphyxia (0/94 (0.00%) vs. 1/94 (1.06%), respectively; χ2= 0.000, P= 1.000). There were no puerperal infections, neonatal scalp injuries, or scalp abscesses found in either group. Using the internal monitoring value as reference, the incidence of FHR false deceleration in external FHR monitoring was 20.21% (19/94 women). Conclusion::Internal FHR monitoring during labor does not increase the incidence of adverse perinatal outcomes. External monitoring was associated with FHR false decelerations.

Objective::To investigate the safety and efficacy of internal electronic fetal heart rate (FHR) monitoring during labor.Methods::This was a retrospective case-control study, which was an analysis of monitoring FHR with a fetal scalp electrode or a Doppler probe (94 pregnant women per group). In the internal monitoring group, when the opening of the uterine orifice was ≥3 cm, the fetal scalp electrode was placed after natural or artificial rupture of the membrane. FHR was simultaneously monitored using a Doppler probe. In the external monitoring group, continuous FHR monitoring was performed using an ultrasound Doppler transducer fixed on the maternal abdomen. The toco transducer was used to record uterine contractions. Pathological examination of the placenta was performed prospectively in 49 and 48 cases in the internal electronic FHR monitoring group and control group, respectively. Maternal-infant outcomes (e.g. fever, puerperal infection, puerperal morbidity, delivery mode, Apgar score, and scalp injury) were recorded. Umbilical artery blood was extracted for blood gas analysis. Differences between the two groups were compared using the paired t-test, χ2 test, Yates corrected χ2 test or Fisher exact test. Results::Non-statistically significant differences between the internal and external monitoring groups were observed in the incidence of neonatal acidosis (1/94 (1.06%) vs. 3/94 (3.19%), respectively; χ2= 0.255, P= 0.613), cesarean section/operative vaginal delivery (8/94 (8.51%) vs. 15/94 (15.96%), respectively; χ2 = 2.427, P= 0.181), fever during labor (18/94 (19.15%) vs. 15/94 (15.96%), respectively; χ2=0.331, P= 0.565), puerperal morbidity (2/94 (2.13%) vs. 3/94 (3.19%), respectively; χ2= 0.000, P= 1.000), chorioamnionitis (9/49 (18.37%) vs. 7/48(14.58%), respectively; χ2= 0.252, P= 0.616), and neonatal asphyxia (0/94 (0.00%) vs. 1/94 (1.06%), respectively; χ2= 0.000, P= 1.000). There were no puerperal infections, neonatal scalp injuries, or scalp abscesses found in either group. Using the internal monitoring value as reference, the incidence of FHR false deceleration in external FHR monitoring was 20.21% (19/94 women). Conclusion::Internal FHR monitoring during labor does not increase the incidence of adverse perinatal outcomes. External monitoring was associated with FHR false decelerations.

Objective: To investigate the microbiological test, antibiotic sensitivity and surgical treatment of periprosthetic joint infection(PJI) cases in post total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients. Methods: A retrospective cross-sectional survey was conducted on 318 patients who underwent THA or TKA in 9 clinical centers in Beijing from January 2014 to December 2016.The data of microbiology, antibiotic sensitivity and surgical treatment were collected.The average age of patients was (62.3±13.1) years old (range: 21-86 years old), including 145 males and 173 females.The body mass index was (25.6±3.8) kg/m ² (range: 15.6-38.1 kg/m²). Results: In total, 318 patients had microorganisms detected by periprosthetic tissue culture or synovial fluid culture, 209 cases (65.7%) had Gram-positive bacteria, 29 cases (9.1%) had Gram-negative bacteria, 10 cases (3.1%) had fungi, 3 cases (0.9%) had non-tuberculous mycobacteria, 72 cases (22.6%) were negative, 69 cases (21.7%) had methicillin-resistant bacteria. The antibiotic sensitivity results showed that the overall resistance rate of penicillin, cefuroxime, amoxicillin+clavulanic acid was 79.9%, 69.9%, and 68.1%, respectively; meropenem, vancomycin, and linezolid resistance rate was 0. For the treatment methods of hip and knee PJI, two-stage revision surgery acounted for 72.9% (108/148) and 64.1% (109/170), respectively. One-stage revision surgery accounted for 21.6% (32/148) and 7.6% (13/170), and open debridement surgery accounted for 4.7%(7/148) and 26.4% (45/170). Conclusions Gram-positive bacteria was still the main pathogen of PJI.The methicillin-resistant bacteria and rare bacteria should be payed attention to. The Majority of hip and knee PJI cases were treated by two-stage revision surgery.

Objective To explore the influence of elevating the oxygen pressure on articular chondrocytes in vitro.Method A hydrogen peroxide induced human articular chondrocyte damage model was established.Then the articular chondrocyte viability was detected using the CCK-8 kit.Collagen Ⅱ(COL Ⅱ),The expression levels of aggrecan (ACAN),matrix metalloproteinase 13 (MMP13) and adisintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) were detected using the realtime PCR and Western blotting.Result The viability of articular chondrocytes improved at 12 h but decreased at 24 h after the stimulation of hydrogen peroxide.Twenty-four hours later,the average expression level of COL Ⅱ and ACAN decreased(P＜0.05),while that of MMP13 and ADAMTS5 elevated(P＞0.05).Conclusion Hydrogen peroxide induced elevation of the extracellular oxygen pressure can influence the synthesis and degradation of the articular chondrocyte extracellular matrix.

Objective To study the radiation dose distribution in the X-ray room,and provide the strategy of radiation protection for the medical staff and the patient’s nursing who had to enter the room while the X-ray was exposing.Methods The thermolumi-nescent dosemeters(TLDs)was placed around the center of the X-ray tube with the same level of the bed.Then,exposure parame-ters,including the X-ray tube voltage value and the field of view,were changed for different groups while exposing.All of the TLDs were taken back to the lab for analysis.Results The differences between the two groups which had the same distance in different di-rections were statistically significant (P <0.01).With the same radiographic condition and direction,the radiation dose on the site of 10 cm from X-ray tube center was the maximum,while the site of 120 cm was the minimum.With the same radiographic condition and distance,the radiation dose on the anode side of the X-ray tube in the room was relative lower,while the site behind the X-ray tube was relative higher.With the same voltage value,distance and direction,the same sites that had the smaller FOV(34 cm×34 cm) received lower radiation dose than those with larger FOV(52.6 cm× 52.6 cm).Meanwhile,the sites with the voltage of 70 kV re-ceived the lower radiation dose than that with the voltage value of 120 kV.Conclusion In the X-ray room,the medical staff and the patient’s nursing can choose the area on the right side(anode side),keep far away from the X-ray tube center,avoid the rear of the X-ray tube and the cathodic direction of the X-ray tube to reduce the radiation dose.

Objective To investigate the effect of propentofylline on nerve growth factor (NGF) and IL-1βrelease from rat cerebral cortical astrocytes. Methods Primary cultured rat astrocytes from SD rats (1-3 d,weighing 6-8 g) after 4 passages were randomly divided into 8 groups ( n = 6 wells each): group Ⅰ control (group C); group Ⅱ , Ⅲ, Ⅳ the astrocytes were exposed to propentofylline 10, 100 and 1000 μmol/L respectively (group P1, P2, P3 ); group Ⅴ the astrocytes were exposed to LPS 1 μg/ml and group Ⅵ, Ⅶ, Ⅷ the astrocytes were exposed to propentofylline 10, 100 and 1000 μmol/L in addition to LPS 1 μg/ml (group P1 + LPS, P2 + LPS,P3 + LPS). The astrocytes were then incubated for 3 days in all 8 groups. The concentrations of IL-1β and NGF in the supernatant were detected at 1 and 3 days of incubation using ELISA. Results LPS activated astrocytes resulting in decrease in NGF release and increase in IL-1β release. Propentofylline significantly increased NGF release and decreased IL-1β release from astrocytes incubated alone or with LPS by suppressing activation of astrocytes. Conclusion Propentofylline can enhance NGF release and inhibit IL-1β release from rat cerebral cortical astrocytes.