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 evaluate the effects of low-frequency ultrasound on antibiotic susceptibility and biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli).Methods:After MRSA and E. coli were treated with low-frequency ultrasound with different parameters, they were divided into a group with different ultrasound durations and a group with different ultrasound powers. With the power parameter set at 100%, the former was divided into 5 subgroups: control, 1.0 min, 2.5 min, 5.0 min, and 10.0 min subgroups. The bacteria were sonicated for 0, 1.0, 2.5, 5.0, 10.0 min, respectively. The group with different ultrasound powers was also divided into 5 subgroups: control, 25% power, 50% power, 75% power, and 100% power subgroups. The bacteria were treated with ultrasonic powers of 0, 25%, 50%, 75%, and 100% for 5.0 min. The MRSA and E. coli corresponded to antibiotic susceptibility testing using vancomycin and meropenem. The number of bacteria surviving was assessed by colony counts. Confocal microscopy was used to observe the changes in biofilms co-cultured with 1/2 minimum inhibitory concentration (MIC) antibiotics after sonication.Results:The E. coli enhanced its susceptibility to meropenem after 5.0 min of high-power sonication while the susceptibility of MRSA to vancomycin was unaffected. The number of E. coli decreased significantly with increasing ultrasound time and power: the numbers of E. coli in the 1.0 min, 2.5 min, 5.0 min, and 10.0 min subgroups [(51.00±18.73), (30.00±9.17), (5.33±4.04), and (0.23±0.03)×10 4 CFU/mL] were significantly smaller than that in the control subgroup [(120.00±7.81)×10 4 CFU/mL], and the numbers of E. coli in the 25%, 50%, 75%, and 100% subgroups [(25.00±3.00), (8.00±2.65), (5.00±2.00), and (5.33±4.04)×10 4 CFU/mL] were significantly smaller than that in the control subgroup [(120.00±7.81)×10 4 CFU/mL] ( P<0.05). However, the number of MRSA was not significantly affected. After treatment with ultrasound combined with 1/2 MIC meropenem, the ratio of live/dead biofilm areas of E. coli decreased significantly with increasing ultrasound time and power: the proportions of E. coli in the 1.0 min, 2.5 min, 5.0 min and 10.0 min subgroups (66.10%±1.78%, 50.84%±7.99%, 60.98%±2.23%, and 29.20%±16.49%) were significantly smaller than those in the control subgroup (93.73%±0.44%), and the proportions of E. coli in the 25%, 50%, 75%, and 100% subgroups (75.23%±2.21%, 65.10%±1.25%, 57.34%±11.21%, and 60.98%±2.23%) were significantly smaller than that in the control subgroup (93.73%±0.44%) ( P<0.05). However, the MRSA live/dead biofilm area ratio was not significantly affected by the treatment with ultrasound combined with 1/2 MIC vancomycin. Conclusions:Low frequency ultrasound can effectively inhibit the growth of E. coli and significantly enhance its sensitivity to antibiotics, and its combination with antibiotics can inhibit the formation of bacterial biofilm. However, low frequency ultrasound or its combination with antibiotics has no significant effect on MRSA.

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 evaluate the effects of low-frequency ultrasound on antibiotic susceptibility and biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli).Methods:After MRSA and E. coli were treated with low-frequency ultrasound with different parameters, they were divided into a group with different ultrasound durations and a group with different ultrasound powers. With the power parameter set at 100%, the former was divided into 5 subgroups: control, 1.0 min, 2.5 min, 5.0 min, and 10.0 min subgroups. The bacteria were sonicated for 0, 1.0, 2.5, 5.0, 10.0 min, respectively. The group with different ultrasound powers was also divided into 5 subgroups: control, 25% power, 50% power, 75% power, and 100% power subgroups. The bacteria were treated with ultrasonic powers of 0, 25%, 50%, 75%, and 100% for 5.0 min. The MRSA and E. coli corresponded to antibiotic susceptibility testing using vancomycin and meropenem. The number of bacteria surviving was assessed by colony counts. Confocal microscopy was used to observe the changes in biofilms co-cultured with 1/2 minimum inhibitory concentration (MIC) antibiotics after sonication.Results:The E. coli enhanced its susceptibility to meropenem after 5.0 min of high-power sonication while the susceptibility of MRSA to vancomycin was unaffected. The number of E. coli decreased significantly with increasing ultrasound time and power: the numbers of E. coli in the 1.0 min, 2.5 min, 5.0 min, and 10.0 min subgroups [(51.00±18.73), (30.00±9.17), (5.33±4.04), and (0.23±0.03)×10 4 CFU/mL] were significantly smaller than that in the control subgroup [(120.00±7.81)×10 4 CFU/mL], and the numbers of E. coli in the 25%, 50%, 75%, and 100% subgroups [(25.00±3.00), (8.00±2.65), (5.00±2.00), and (5.33±4.04)×10 4 CFU/mL] were significantly smaller than that in the control subgroup [(120.00±7.81)×10 4 CFU/mL] ( P<0.05). However, the number of MRSA was not significantly affected. After treatment with ultrasound combined with 1/2 MIC meropenem, the ratio of live/dead biofilm areas of E. coli decreased significantly with increasing ultrasound time and power: the proportions of E. coli in the 1.0 min, 2.5 min, 5.0 min and 10.0 min subgroups (66.10%±1.78%, 50.84%±7.99%, 60.98%±2.23%, and 29.20%±16.49%) were significantly smaller than those in the control subgroup (93.73%±0.44%), and the proportions of E. coli in the 25%, 50%, 75%, and 100% subgroups (75.23%±2.21%, 65.10%±1.25%, 57.34%±11.21%, and 60.98%±2.23%) were significantly smaller than that in the control subgroup (93.73%±0.44%) ( P<0.05). However, the MRSA live/dead biofilm area ratio was not significantly affected by the treatment with ultrasound combined with 1/2 MIC vancomycin. Conclusions:Low frequency ultrasound can effectively inhibit the growth of E. coli and significantly enhance its sensitivity to antibiotics, and its combination with antibiotics can inhibit the formation of bacterial biofilm. However, low frequency ultrasound or its combination with antibiotics has no significant effect on MRSA.

OBJECTIVE To systematically evaluate the efficacy and safety of intrawound vancomycin powder for preventing surgical site infections in total knee and total hip arthroplasty. METHODS Computer retrieval of PubMed, Embase, Web of Science, the Cochrane Library, CNKI, Wanfang Database, Chinese Biomedical Literature Database, The clinical research about intrawound vancomycin in total knee arthroplasty(TKA) and total hip arthroplasty(THA) for the prevention of surgical site infections were screened. The quality of included studies was assessed using the Cochrane risk bias assessment tool and the Newcastle-Ottawa Scale. Meta-analysis was performed using RevMan 5.4 software. RESULTS Finally, 20 literature were included, including 1 prospective randomized controlled trial, 2 prospective cohort study, and 17 retrospective cohort study, with a total of 34900 patients. Meta-analysis showed that interventional group had a decreased tolal rate of prosthetic joint infection(PJI)[OR=0.44, 95%CI(0.35−0.56), P<0.000 01] and superficial infection[OR=0.27, 95%CI(0.19−0.41), P<0.000 01]compared with control group. Subgroup analysis showed that TKA and THA, primary and revision patients who received intrawound vancomycin had lower rates of PJI, the differences were statistical significance(P<0.05). Meta-analysis of 11 studies reported adverse reaction suggested that the total rate of adverse reactions in the intervention group(7.68%) was higher than that in the control group(5.68%) with significant differences[OR=1.47, 95%CI(1.14−1.89), P=0.003)]. CONCLUSION The current literature suggests that intrawound vancomycin can decrease the rate of PJI and superficial infection in primary and revision TKA and THA , however, it may increase risk of aseptic wound complications and other adverse reaction.

Objective:To investigate the clinical outcomes and efficacy of trabecular metal (TM) cones for the reconstruction of metaphyseal bone defects in revision total knee arthroplasty.Methods:A retrospective analysis was conducted on 46 patients (47 knees), who underwent revision total knee arthroplasty with TM cones for metaphyseal defect reconstruction from July 2015 to August 2023. The cohort comprised 12 males and 34 females, ranging from 41 to 83 years of age, with a mean of 68.65 ± 9.09 years. Body mass index (BMI) ranged from 19.5 to 36.0 kg/m 2, averaging 27.20±4.50 kg/m 2. Bone defects were stratified according to the Anderson Orthopedic Research Institute (AORI) classification, including 64 sides (AORI T2B type 20 sides, T3 type 16 sides, F2B type 11 sides, F3 type 17 sides) which were addressed with 67 cones. Evaluations during follow-up included range of motion (ROM), visual analogue scale (VAS) for pain, and the American Knee Society Score (KSS). Long leg radiographs and knee X-rays were reassessed for femorotibial angle (FTA) and joint alignment, osseointegration of the TM cones, and any complications were documented. Results:The average follow-up duration was 46.22±26.55 months (range 16-103 months). The KSS knee score significantly improved from 29.22±19.79 preoperatively to 88.22±6.01 at the final follow-up ( F=258.118, P<0.001). Similarly, the KSS function score saw a marked increase from a preoperative average of 7.65±8.21 to 56.30±6.10 at the final follow-up ( F=354.711, P<0.001). VAS scores significantly decreased from 5.35±1.50 preoperatively to 0.28±0.50 at the final follow-up ( F=300.934, P<0.001). ROM improved from 67.72°±34.62° preoperatively to 85.33°±9.15° at the final follow-up ( F=7.798, P<0.001), and the FTA improved from 179.24°±10.30° preoperatively to 174.39°±1.69° at the final follow-up, a statistically significant enhancement ( F=9.123, P<0.001). Osseointegration was observed in 95.5% of the cases (64/67 cones). There were no instances of osteolysis or aseptic loosening observed, indicating stable prosthetic fixation. Complications were minimal, with one reported case of a femoral shaft fracture, which was successfully treated with internal fixation, resulting in satisfactory healing at 6 months. At the last follow-up (3 years after operation), the patient could walk at home with a walker and the other patients had no complications such as periprosthetic joint infection, dislocation and periprosthetic fracture. Conclusion:The application of trabecular metal cones in revision total knee arthroplasty provides an effective solution for the reconstruction of severe metaphyseal bone defects, enhancing prosthetic stability and restoring the knee joint's mechanical alignment. The trend towards successful osseointegration in the TM cones is promising, and a significant improvement in knee joint function has been observed.

Objective:To explore the in vitro antibacterial effects of low-intensity pulsed ultrasound (LIPUS) combined with 3.5 g/L povidone iodine solution on the biofilm of methicillin-resistant staphylococcus aureus (MRSA). Methods:Immature (cultured for 24 hours) and mature (cultured for 72 hours) MRSA biofilms were established on the surfaces of glass slides or confocal dishes. They were randomly divided into 4 groups ( n=9) according to different intervention methods. In the control group, glass slides or confocal dishes were placed in 500 mL of physiological saline for 3 minutes; in the PI group, glass slides or confocal dishes were placed in 500 mL of 3.5 g/L povidone iodine solution for 3 minutes; in the LIPUS group, glass slides or confocal dishes were placed in 500 mL of physiological saline and simultaneously intervened with LIPUS for 3 minutes; in the LIPUS & PI group, glass slides or confocal dishes were placed into 500 mL of 3.5 g/L povidone iodine solution and simultaneously intervened with LIPUS for 3 minutes. After intervention, confocal microscopy (CLSM) and scanning electron microscopy (SEM) were used to observe and compare the structure, morphology, bacterial survival, and viable cell count of the MRSA biofilms among the 4 groups. Results:On the MRSA biofilms cultured for 24 and 72 hours, CLSM and SEM observed sparse biofilms in the LIPUS group and LIPUS & PI group, and also a large number of dead bacteria in the LIPUS & PI group. On the MRSA biofilms cultured for 24 hours, the bacterial colony counts in the control group, PI group, LIPUS group, and LIPUS & PI group were (1.21±0.45)×10 6 CFU/mL, (3.38±2.81)×10 3 CFU/mL, (1.82±0.37)×10 3 CFU/mL, and (69.67±27.93) CFU/mL, respectively. Except for the comparison between PI group and LIPUS group, which showed no statistically significant difference ( P>0.05), there were statistically significant differences between the other groups when compared pairwise ( P<0.05). On the MRSA biofilms cultured for 72 hours, the bacterial colony counts in the control group, PI group, LIPUS group, and LIPUS & PI group were (3.01±0.70)×10 6 CFU/mL, (1.80±1.52)×10 5 CFU/mL, (2.10±0.52)×10 3 CFU/mL, and (68.67±19.55) CFU/mL, respectively. There were statistically significant differences between the 4 groups when compared pairwise ( P<0.05). Conclusions:Application of LIPUS or 3.5 g/L povidone iodine alone for 3 minutes on the immature or mature MRSA biofilms in vitro only leads to partial antibacterial activity. However, LIPUS can enhance the in vitro antibacterial effect of 3.5 g/L povidone iodine on the MRSA biofilms at different maturity levels.

Objective:To evaluate the clinical efficacy of single-stage total hip arthroplasty (THA) combined with intra-articular antibiotic injection in managing postoperative infections following internal fixation of hip fractures.Methods:A retrospective analysis was conducted on 25 patients who underwent single-stage THA for infection following internal fixation of hip fractures from January 2013 to January 2021 at the Department of Joint Surgery, First Affiliated Hospital of Xinjiang Medical University. The cohort comprised 15 males and 10 females, with an average age of 61.52±13.06 years (range, 32-89 years) and an average body mass index of 24.04±3.84 kg/m 2 (range, 18-34 kg/m 2). The fractures included 13 femoral neck fractures, 6 intertrochanteric fractures, 4 acetabular fractures, 1 proximal femoral fracture, and 1 combined acetabular and intertrochanteric fracture. Preoperative joint cavity puncture or intraoperative joint fluid extraction, biochemical analysis, microbial culture, and drug sensitivity tests were performed. During surgery, infected internal fixation devices were removed, and hip prostheses were implanted following thorough debridement. Postoperatively, patients received intravenous and intra-articular sensitive antibiotics based on bacterial culture and drug sensitivity results. Joint stability was evaluated according to the Engh standard, and hip function was assessed using the Harris score. Results:Microbial cultures were positive in 12 cases, identifying Staphylococcus epidermidis (4 cases), Staphylococcus aureus (2 cases), Escherichia coli (2 cases), Enterobacter cloacae (1 case), Pseudomonas aeruginosa (1 case), Corynebacterium striatum (1 case), and a mixed infection of Staphylococcus epidermidis and Enterococcus faecalis (1 case). All 25 patients were followed for an average of 56.64±26.38 months (range, 24-123 months). Intravenous and intra-articular antibiotic treatment was administered to all patients. One case experienced sinus tract formation and pus discharge on the 20th postoperative day, diagnosed as periprosthetic infection, resulting in treatment failure, yielding an infection control rate of 96% (24/25). All patients demonstrated stable prosthesis fixation with no subsidence, loosening, or osteolysis. At the final follow-up, the Harris hip score improved significantly from a preoperative score of 26.69±13.47 to 92.30±5.60 ( t=22.882, P<0.001). Complications included 2 cases of hip dislocation, 2 cases of deep venous thrombosis in the lower extremities, 1 case of poor wound healing, and 1 case of periprosthetic fracture. Conclusion:Single-stage THA combined with intra-articular antibiotic injection is effective in controlling infections following internal fixation of hip fractures. This approach not only achieves a high infection control rate but also reconstructs hip joint function, resulting in satisfactory postoperative outcomes.

Arthroplasty, Replacement, Knee ; Humans ; Knee Joint/surgery* ; Leg ; Lower Extremity/diagnostic imaging* ; Osteoarthritis, Knee/surgery* ; Rotation ; Tibia/surgery*

Objective:To investigate the threshold of serum C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), synovial fluid white blood-cell count (WBC) and polymorphonuclear cells (PMN) proportion in the diagnosis of periprosthetic joint infection (PJI) in patients with rheumatoid arthritis (RA).Methods:The clinical data of 246 patients with RA and osteoarthritis (OA) who had previously undergone total knee and hip arthroplasty from January 2006 to December 2019 was retrospectively analyzed. The patients were divided into four groups according to the disease type and whether PJI occurred, namely 46 patients in the RA-PJI group, 64 patients in the RA-non-PJI group, 72 patients in the OA-PJI group, and 64 patients in the OA-non-PJI group. The receiver operating characteristics (ROC) curve was used to determine the optimum cut-off values of CRP, ESR, synovial fluid WBC and PMN proportion for diagnosing the RA-PJI and OA-PJI. The optimal cut-off values of serum and synovial fluid indexes were evaluated for the diagnostic efficacy of RA-PJI by comparing the area under curve (AUC) of each index. Further, the values were applied for joint test analysis.Results:For PJI prediction, the results of serological and synovial fluid indexes were different between RA-PJI group and OA-PJI group. The results of ROC curve analysis showed that the optimal cut-off values of each detection index were as follows. The optimal cut-off value of CRP for diagnosing RA-PJI was 14.4 mg/L, ESR was 39 mm/1 h, synovial fluid WBC was 3 654×10 6 /L, and PMN proportion was 0.659. The optimal cut-off value for diagnosing OA-PJI were 8.16 mg/L, 31 mm/1 h, 2 452×10 6 /L, and 0.625, respectively. In the RA-PJI group, the difference between the AUC of each detection index and AUC=0.5 was statistically significant ( P<0.05). Among them, the specificity of synovial fluid WBC was 92.3%, AUC was 0.879 (95% CI: 0.776, 0.982) with 87.8% positive predictive value and 10.21 positive likelihood ratio. These values were higher than those of CRP, ESR, and PMN proportion. The results of joint test analysis for the diagnosis of RA-PJI were as follows. The specificity of the series test was 100%, and the sensitivity of the parallel test was 100%; the specificity of the joint index diagnostic test was 100%, AUC was 0.926 (95% CI: 0.848, 1.000), the difference between AUC and AUC=0.5 was statistically significant ( P<0.05). Conclusion:The optimum cut-off values of CRP, ESR, synovial fluid WBC and PMN proportion for the diagnosis of PJI in patients with RA are all higher than those of patients with OA. Their optimal cut-off values can be used as important auxiliary indexes for a clear diagnosis of PJI in patients with RA. Compared with other indexes, the synovial fluid WBC has strong predicting power and lower misdiagnosis rate, which could be the best detection index for identifying PJI in patients with RA. The joint test could improve the sensitivity or specificity of PJI diagnosis in patients with RA. The combination with multiple detection indexes could provide a reference for the early and accurate diagnosis of PJI in patients with RA.