BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

BACKGROUND:Periprosthetic joint infection is the most common cause of early failure after total knee replacement.The current methods of preventing periprosthetic joint infection by improving the surface of the prosthesis have limitations to varying degrees.OBJECTIVE:To construct a coating material that can stably improve the surface of the implant,prevent the initial floating bacterial infection of periprosthetic infection,and regulate the bone transfer function around the implant.METHODS:(1)Material preparation:YGF polypeptide(which promotes bone formation),LL-37 polypeptide(with antibacterial properties)and YGF+LL-37 composite peptide were prepared by Fmoc solid phase peptide synthesis technology.The titanium-based materials were immersed in the three polypeptide solutions for 2 hours to obtain YGF coating,LL-37 coating and composite peptide coating coated titanium sheets.(2)In vitro experiment:Uncoated titanium sheets and coated titanium sheets were co-cultured with Escherichia coli(or Staphylococcus aureus)and the colonies were counted by plate method.MC3T3 cells were inoculated on the surface of uncoated titanium sheet and coated titanium sheet,respectively.Alizarin red staining was used to observe the calcium salt deposition on the surface of the material.Western blot assay was used to detect the protein expression of RUNX2,osteocalcin,osteopontin,and bone morphogenetic protein 2.(3)Animal experiment:24 SD rats were randomly divided into three groups:the blank group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal;the control group(n=8)was implanted with uncoated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension;the experimental group(n=8)was implanted with composite peptide coated titanium nails in the femoral medullary canal+intra-articular injection of Staphylococcus aureus suspension.After 5 weeks of implantation,micro-CT examination,hematoxylin-eosin staining and immunohistochemical staining of femur specimens were performed.RESULTS AND CONCLUSION:(1)In vitro experiment:Compared with uncoated titanium sheet and YGF coated titanium sheet,LL-37 coated and composite peptide coated titanium sheet could significantly inhibit the growth and reproduction of Escherichia coli and Staphylococcus aureus.Compared with uncoated titanium sheets and LL-37-coated titanium sheets,YGF-coated and composite peptide-coated titanium sheets could promote calcium salt deposition in osteoblasts and increase the protein expression of RUNX2,osteocalcin,osteopontin and bone morphogenetic protein 2.(2)Animal experiment:Micro-CT test showed that the control group had less bone mass than the blank group and the experimental group.Hematoxylin-eosin staining showed that there was a large amount of fibrous tissue around the nail channel in the control group,only a small amount of tissue fibrosis around the nail channel in the blank group,and only a small amount of tissue fibrosis around the nail channel in the experimental group.Immunohistochemical staining showed that the protein expression of interleukin 1β and tumor necrosis factor α in the control group was higher than that in the blank group and the experimental group,and the expression of osteocalcin,RUNX2 and osteopontin in the experimental group was higher than that in the blank group and the control group.(3)The results show that the titanium-based material coated with YGF+LL-37 composite peptide coating has good antibacterial ability and can promote bone transfer around the implant.

Definitive chemoradiotherapy (dCRT) has become a cornerstone in the treatment of locally advanced esophageal cancer; however, local control remains suboptimal, and persistent lesions or locoregional recurrences after treatment are not uncommon. For patients without distant metastases but with local failure, whether surgical intervention can still offer curative potential remains a major clinical dilemma. Salvage esophagectomy (SE) offers potential long-term survival for selected patients, but this procedure is performed in the context of severe fibrosis, impaired local blood supply, and obscured anatomical planes following chemoradiotherapy, resulting in significantly higher perioperative risk compared to primary esophagectomy. Consequently, controversies exist regarding patient selection, preoperative restaging, choice of surgical approach, extent of lymphadenectomy, gastrointestinal reconstruction, and perioperative management. In recent years, with the refinement of restaging modalities such as PET/CT, the accumulation of experience in high-volume centers, and emerging evidence from clinical studies, the clinical role of SE has gradually shifted from a "high-risk salvage measure" to a "selective curative strategy aimed at achieving long-term survival in carefully selected patients". Nevertheless, standardized guidelines for patient selection, technical approaches, and perioperative management are still lacking. Based on current evidence and clinical experience, experts organized by the Integrated Esophageal Cancer Committee of Chinese Anti-Cancer Association systematically reviewed key issues regarding SE, including its definition, indications, preoperative evaluation, choice of surgical approach, lymphadenectomy, gastrointestinal reconstruction, and perioperative management, and formulated a Chinese expert consensus. This consensus aims to provide guidance for standardized assessment, appropriate referral, individualized surgical decision-making, and optimized perioperative management of patients with locoregional failure after dCRT. Ultimately, this will increase the likelihood of R0 resection, reduce the risk of severe complications, and promote the safer, more judicious, and standardized implementation of SE in high-risk scenarios.

Objective To investigate the effect of activating α7 nicotinic acetylcholine receptor （α7nAChR） on calcium chloride （CaCl₂）-induced abdominal aortic aneurysm （AAA） injury in mice. Methods AAA model was induced by CaCl₂ in wild type （WT） mice and α7nAChR knockout （α7nAChR^−/−） mice. The effects of knockout of α7nAChR on histological damage in CaCl₂-induced AAA mice and expression of inflammatory factors were assessed by HE staining, Elasticavan Gieson （EVG） staining and IHC staining. Rat-derived primary vascular smooth muscle cells （VSMC） were stimulated with tumor necrosis factor-α （TNF-α）, which mimicked the inflammatory environment of AAA. The expressions of inflammation-related proteins were detected by using Western-blot （WB） with or without PNU-282987 to activate α7nAChR. Results Aortic dilatation was obvious, and the aortic structure was disrupted in CaCl₂-induced AAA mice. Knockout of α7nAChR further exacerbated the histological injury and significantly up-regulated the expression of inflammation-related proteins in aorta of AAA mice. It was showed that TNF-α stimulation of VSMC increased inflammation-related protein expression, whereas activation of α7nAChR prevented the phenomenon. Conclusion Activation of α7nAChR could attenuate CaCl₂-induced AAA injury in mice by suppressing the inflammatory response.

Objective:To investigate the diagnostic efficacy of intraoperative direct sonication in periprosthetic joint infection (PJI).Methods:This is a retrospective case series study. The clinical data of 490 patients with PJI or aseptic prosthesis loosening after hip or knee arthroplasty admitted to the Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University from January 2018 to December 2023 were retrospectively analyzed. There were 209 male cases, 281 female cases, aged ( M(IQR)) 63 (19) years (range: 15 to 89 years). There were 328 cases of PJI (123 cases of traditional sonication, 205 cases of intraoperative direct sonication, and 204 cases had simultaneous intraoperative synovial fluid), and 162 patients of aseptic loosening (89 cases of traditional sonication, 73 cases of intraoperative direct sonication, and 96 cases had simultaneous intraoperative synovial fluid). The method of traditional sonication: the prosthesis components were placed in a sterile container, vortexed for 30 seconds, then placed in an ultrasound bath to sonication (frequency:(40±2) kHz, power density:(0.22±0.04) W/cm2) for 5 minutes, vortexed again for 30 seconds, and the resulting sonicate fluid was extracted for culture. The method of intraoperative direct sonication: during the operation, the surgical area, the prosthesis and the tissues around the prosthesis which were placed in a sterile container were respectively subjected to sonication for 5 minutes using a portable handheld ultrasonic cell disruptor device (frequency: 25 kHz, power density:(0.22±0.04) W/cm2), and the fluids before and after sonication were extracted for culture. The method of intraoperative synovial fluid: during the operation, the joint capsule was incised, and the synovial fluid was extracted under direct vision for culture. The sensitivity, specificity, positive and negative predictive values, Youden index, the effect of preoperative antimicrobial agents on culture results, and culture duration for different culture methods. Receiver operating characteristic (ROC) curves were plotted, and the diagnostic efficacy of these methods for PJI was compared using the χ2 test, the Wilcoxon signed-rank test, and other appropriate statistical methods. Results:The sensitivity of intraoperative direct sonication was significantly higher than that of intraoperative synovial fluid culture (89.8%(184/205) vs.56.9%(116/204), χ2=44.457, P<0.01) and traditional sonication (89.8%(184/205) vs.66.7%(82/123), χ2=121.588, P<0.01). However, its specificity was lower compared to intraoperative synovial fluid (87.5%(64/73) vs. 99.0%(95/96), χ2=9.491, P=0.002). The culture duration for intraoperative direct sonication was shorter than for intraoperative synovial fluid 87.0 (41.8) hours vs. 112.5 (78.5) hours, Z=-5.121, P<0.01) and traditional sonication (87.0 (41.8) hours vs. 119.0 (67.5) hours, Z=-7.119, P<0.01). Gram-positive bacteria (predominantly Staphylococcus aureus and Staphylococcus epidermidis) were the most common isolates across all three culture methods. Furthermore, intraoperative direct sonication was more likely to detect polymicrobial infections compared to traditional sonication (38.6% vs. 2.4%, χ2=37.223, P<0.01) and intraoperative synovial fluid (38.6% vs. 0.9%, χ2=55.527, P<0.01). The ROC curve revealed that the area under the curve of intraoperative direct sonication,intraoperative synovial fluid culture and traditional sonication were 0.886 (95% CI:0.843 to 0.930), 0.779 (95% CI:0.743 to 0.815) and 0.788 (95% CI: 0.736 to 0.839). Conclusions:Compared with intraoperative synovial fluid and traditional sonication, intraoperative direct sonication has excellent sensitivity, the shortest appropriate culture duration for pathogenic bacteria, and it is more likely to diagnose PJI patients with polymicrobial infections, having better diagnostic efficacy in the diagnosis of PJI.

OBJECTIVE: To investigate the analgesic effect of locally injecting a "cocktail" analgesia containing a high-dose compound betamethasone during revision hip arthroplasty, and also to study the usage of opioid drugs. METHODS: A retrospective analysis was conducted on the clinical data of 180 patients who underwent revision hip arthroplasty due to aseptic loosening of the hip prosthesis between January 2015 and December 2021. Among them, 95 patients received intraoperative injection of "cocktail" analgesia containing high-dose compound betamethasone (group A), and 85 patients received intraoperative injection of traditional "cocktail" analgesia (group B). There was no significant difference in baseline data such as gender, age, body mass index, presence or absence of diabetes mellitus between the two groups ( P>0.05). The hospital stay, use of opioid drugs within 72 hours, and the incidence of adverse reactions within 72 hours after operation [including nausea and vomiting, insomnia, deep venous thrombosis (DVT), infection, etc.] were recorded and compared between the two groups. The pain relief of patients was evaluated using the static and dynamic visual analogue scale (VAS) scores at 12, 24, 48, and 72 hours after operation. The incidence of complications (including prosthesis re-loosening, hip joint dislocation, hip joint stiffness, limping, chronic pain, etc.) at 2 years after operation was recorded, and the Harris Hip Score (HHS) was used to evaluate the function at 2 years after operation. RESULTS: In group A, the utilization rate of opioid drugs within 72 hours after operation was significantly lower than that in group B ( P<0.05). However, there was no significant difference between the two groups in terms of hospital stay, as well as the incidence of adverse reactions such as nausea and vomiting, insomnia, DVT, and infection within 72 hours after operation ( P>0.05). The VAS scores of both groups decreased with time, and the differences between different time points were significant ( P<0.05). The static and dynamic VAS scores of group A were significantly lower than those of group B at 12, 24, and 48 hours after operation ( P<0.05), but there was no significant difference in static and dynamic VAS scores between the two groups at 72 hours after operation ( P>0.05). All patients in both groups were followed up 2-8 years, with an average of 5.73 years. At 2 years after operation, no significant difference was found between the two groups in the incidence of complications and HHS score ( P>0.05). CONCLUSION "Cocktail" analgesia containing a high-dose compound betamethasone for early analgesia after revision hip arthroplasty can effectively reduce postoperative pain and the use of opioid drugs, but will not increase the incidence of infection and DVT after operation.
Humans ; Arthroplasty, Replacement, Hip/adverse effects* ; Betamethasone/therapeutic use* ; Retrospective Studies ; Male ; Female ; Analgesics, Opioid/administration & dosage* ; Pain, Postoperative/prevention & control* ; Middle Aged ; Reoperation ; Aged ; Analgesia/methods* ; Adult ; Pain Measurement ; Pain Management/methods* ; Prosthesis Failure ; Hip Prosthesis

Objective:To investigate the related factors for unexpected positive intraoperative cultures (UPC) in patients undergoing aseptic hip revision and the long-term prosthesis survival rate in such patients.Methods:A retrospective cases series analysis was conducted in 397 patients who underwent aseptic hip revision surgery at the Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University from January 2012 to December 2021. There were 225 females and 172 males with an age ( M(IQR)) of 58(23) years (range:21 to 89 years) and a body mass index (BMI) of 25(6) kg/m 2 (range:15 to 39 kg/m 2). Based on the culture results of intraoperative specimens, patients were divided into culture-positive group (32 cases) and culture-negative group (365 cases). The clinical data were analyzed including gender, age, BMI, preoperative C-reactive protein, preoperative erythrocyte sedimentation rate, American Society of Anesthesiologists(ASA) classification, preoperative urinary bacteria, preoperative hypoproteinemia; comorbidities of diabetes mellitus, anemia, chronic obstructive pulmonary disease, cerebral infarction; history of allergy to antibiotics, smoking, drinking, previous prosthetic dislocation, previous surgical intervention; and time from symptom onset to admission, duration of surgery, etc. A univariate analysis was performed by Mann-Whitney U orχ2 test and the independent risk factors were identified by including the independent variables with P<0.20 in the univariate analysis in a logistic regression analysis of dichotomous variables. The study outcomes were defined as :(1) re-surgical treatment for any reason; (2)symptoms of infection such as sinus and incision seepage; (3) persistent excessive hip pain.The Kaplan-Meier survival curve was plotted using the study outcome of any cause as the endpoint event, and the log-rank test was used to compare the 10-year survival rate of the prosthesis in the culture-negative group with that in the culture-positive group. Results:Univariate analysis showed statistically significant differences between the culture-negative and culture-positive groups when comparing gender, BMI, ASA classification, and preoperative urinary bacterial results ( χ2=2.368, P=0.124; χ2=-1.648, P=0.098; χ2=14.128, P=0.003; and χ2=7.384, P=0.007). Logistic regression analysis showed that male, ASA classification Ⅳ, and positive preoperative urinary bacteria were independent risk factors for the development of UPC during aseptic hip revision( OR=2.35,95% CI:1.08 to 5.36, P=0.040; OR=37.32,95% CI:1.80 to 1 810.63, P=0.030; OR=4.11,95% CI:1.40 to 11.12, P=0.012). The follow-up time of the 397 patients included in this study was 70 (134) months (range:12 to 146 months). The Kaplan-Meier survival curves showed that the 10-year survival rates of the prostheses in the culture-negative and culture-positive groups were 95.7% and 75.0%, respectively. There was no statistically significant difference in the 10-year survival rate comparing the two groups ( P=0.661). Conclusions:UPC is more likely to occur in patients undergoing hip revision due to noninfectious factors in those who are male, have positive preoperative urinary bacteria, and have an ASA classification of Ⅳ. Intraoperative specimen culture results (negative or positive) do not affect 10-year prosthesis survival rate after hip revision.

Objective:To investigate the related factors for unexpected positive intraoperative cultures (UPC) in patients undergoing aseptic hip revision and the long-term prosthesis survival rate in such patients.Methods:A retrospective cases series analysis was conducted in 397 patients who underwent aseptic hip revision surgery at the Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University from January 2012 to December 2021. There were 225 females and 172 males with an age ( M(IQR)) of 58(23) years (range:21 to 89 years) and a body mass index (BMI) of 25(6) kg/m 2 (range:15 to 39 kg/m 2). Based on the culture results of intraoperative specimens, patients were divided into culture-positive group (32 cases) and culture-negative group (365 cases). The clinical data were analyzed including gender, age, BMI, preoperative C-reactive protein, preoperative erythrocyte sedimentation rate, American Society of Anesthesiologists(ASA) classification, preoperative urinary bacteria, preoperative hypoproteinemia; comorbidities of diabetes mellitus, anemia, chronic obstructive pulmonary disease, cerebral infarction; history of allergy to antibiotics, smoking, drinking, previous prosthetic dislocation, previous surgical intervention; and time from symptom onset to admission, duration of surgery, etc. A univariate analysis was performed by Mann-Whitney U orχ2 test and the independent risk factors were identified by including the independent variables with P<0.20 in the univariate analysis in a logistic regression analysis of dichotomous variables. The study outcomes were defined as :(1) re-surgical treatment for any reason; (2)symptoms of infection such as sinus and incision seepage; (3) persistent excessive hip pain.The Kaplan-Meier survival curve was plotted using the study outcome of any cause as the endpoint event, and the log-rank test was used to compare the 10-year survival rate of the prosthesis in the culture-negative group with that in the culture-positive group. Results:Univariate analysis showed statistically significant differences between the culture-negative and culture-positive groups when comparing gender, BMI, ASA classification, and preoperative urinary bacterial results ( χ2=2.368, P=0.124; χ2=-1.648, P=0.098; χ2=14.128, P=0.003; and χ2=7.384, P=0.007). Logistic regression analysis showed that male, ASA classification Ⅳ, and positive preoperative urinary bacteria were independent risk factors for the development of UPC during aseptic hip revision( OR=2.35,95% CI:1.08 to 5.36, P=0.040; OR=37.32,95% CI:1.80 to 1 810.63, P=0.030; OR=4.11,95% CI:1.40 to 11.12, P=0.012). The follow-up time of the 397 patients included in this study was 70 (134) months (range:12 to 146 months). The Kaplan-Meier survival curves showed that the 10-year survival rates of the prostheses in the culture-negative and culture-positive groups were 95.7% and 75.0%, respectively. There was no statistically significant difference in the 10-year survival rate comparing the two groups ( P=0.661). Conclusions:UPC is more likely to occur in patients undergoing hip revision due to noninfectious factors in those who are male, have positive preoperative urinary bacteria, and have an ASA classification of Ⅳ. Intraoperative specimen culture results (negative or positive) do not affect 10-year prosthesis survival rate after hip revision.

Objective:To investigate the diagnostic efficacy of intraoperative direct sonication in periprosthetic joint infection (PJI).Methods:This is a retrospective case series study. The clinical data of 490 patients with PJI or aseptic prosthesis loosening after hip or knee arthroplasty admitted to the Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University from January 2018 to December 2023 were retrospectively analyzed. There were 209 male cases, 281 female cases, aged ( M(IQR)) 63 (19) years (range: 15 to 89 years). There were 328 cases of PJI (123 cases of traditional sonication, 205 cases of intraoperative direct sonication, and 204 cases had simultaneous intraoperative synovial fluid), and 162 patients of aseptic loosening (89 cases of traditional sonication, 73 cases of intraoperative direct sonication, and 96 cases had simultaneous intraoperative synovial fluid). The method of traditional sonication: the prosthesis components were placed in a sterile container, vortexed for 30 seconds, then placed in an ultrasound bath to sonication (frequency:(40±2) kHz, power density:(0.22±0.04) W/cm2) for 5 minutes, vortexed again for 30 seconds, and the resulting sonicate fluid was extracted for culture. The method of intraoperative direct sonication: during the operation, the surgical area, the prosthesis and the tissues around the prosthesis which were placed in a sterile container were respectively subjected to sonication for 5 minutes using a portable handheld ultrasonic cell disruptor device (frequency: 25 kHz, power density:(0.22±0.04) W/cm2), and the fluids before and after sonication were extracted for culture. The method of intraoperative synovial fluid: during the operation, the joint capsule was incised, and the synovial fluid was extracted under direct vision for culture. The sensitivity, specificity, positive and negative predictive values, Youden index, the effect of preoperative antimicrobial agents on culture results, and culture duration for different culture methods. Receiver operating characteristic (ROC) curves were plotted, and the diagnostic efficacy of these methods for PJI was compared using the χ2 test, the Wilcoxon signed-rank test, and other appropriate statistical methods. Results:The sensitivity of intraoperative direct sonication was significantly higher than that of intraoperative synovial fluid culture (89.8%(184/205) vs.56.9%(116/204), χ2=44.457, P<0.01) and traditional sonication (89.8%(184/205) vs.66.7%(82/123), χ2=121.588, P<0.01). However, its specificity was lower compared to intraoperative synovial fluid (87.5%(64/73) vs. 99.0%(95/96), χ2=9.491, P=0.002). The culture duration for intraoperative direct sonication was shorter than for intraoperative synovial fluid 87.0 (41.8) hours vs. 112.5 (78.5) hours, Z=-5.121, P<0.01) and traditional sonication (87.0 (41.8) hours vs. 119.0 (67.5) hours, Z=-7.119, P<0.01). Gram-positive bacteria (predominantly Staphylococcus aureus and Staphylococcus epidermidis) were the most common isolates across all three culture methods. Furthermore, intraoperative direct sonication was more likely to detect polymicrobial infections compared to traditional sonication (38.6% vs. 2.4%, χ2=37.223, P<0.01) and intraoperative synovial fluid (38.6% vs. 0.9%, χ2=55.527, P<0.01). The ROC curve revealed that the area under the curve of intraoperative direct sonication,intraoperative synovial fluid culture and traditional sonication were 0.886 (95% CI:0.843 to 0.930), 0.779 (95% CI:0.743 to 0.815) and 0.788 (95% CI: 0.736 to 0.839). Conclusions:Compared with intraoperative synovial fluid and traditional sonication, intraoperative direct sonication has excellent sensitivity, the shortest appropriate culture duration for pathogenic bacteria, and it is more likely to diagnose PJI patients with polymicrobial infections, having better diagnostic efficacy in the diagnosis of PJI.

BACKGROUND:Nanocomposite hydrogel has great research prospects and application potential in the treatment of osteoarthritis. OBJECTIVE:To review the research progress of nanocomposite hydrogel in osteoarthritis and cartilage repair. METHODS:Databases such as CNKI and PubMed were searched.The English key words were"nanocomposite hydrogel,nanogel,osteoarthritis,cartage,physical encapsulation,electrostatic interaction,covalent crosslinking",and the Chinese key words were"nanocomposite hydrogel,nanogel,osteoarthritis,cartage,physical encapsulation,physical encapsulation,electrostatic effect,covalent cross-linking".After an initial screening of all articles based on inclusion and exclusion criteria,71 articles with high correlation were retained for review. RESULTS AND CONCLUSION:In cell or animal experiments,nanocomposite hydrogel has the effect of improving osteoarthritis.Nanocomposite hydrogel can promote cartilage repair,improve the internal environment of osteoarthritis,and achieve the therapeutic purpose of osteoarthritis by improving the mechanical environment between joints,carrying targeted drugs,and promoting the chondrogenesis of seed cells.At present,the research of nanocomposite hydrogel in osteoarthritis disease still has a huge space to play.It is expected to open up a new way for the clinical treatment of osteoarthritis by continuing to deepen the research of material preparation and actively carrying out cell and animal experiments.