Objective To investigate the feasibility of bone marrow mesenchymal stem cells (BMSCs) combined with type Ⅱ collagen-hyaluronic acid-oxidized chondroitin sulfate (Col Ⅱ-HA-OCS) biomimetic hydrogel to repair articular cartilage defect in porcine and the role of the transplanted cells played in the process of cartilage repair.Methods A articular cartilage defect model which remaining cartilage calcified zone was created in the knee of Bama minipigs,the autologous BMSCs was used as seeds for transplantation and was labeled by the 5,6-carboxyfluorescein diacetate succinimidyl ester (CFDA SE).Animals were randomly divided into three groups:Group A (blank group) was left untreated,group B (cell-free biomimetic hydrogel group) was filled with biomimetic hydrogel and group C (BMSCs combined with biomimetic hydrogel group) was filled with the CFDA SE labeled autologous BMSCs combined with biomimetic hydrogel.One month after the operation,BrdU labeled liquid was injected intravenously into the animals 24 h and 48 h before specimens were taken from the executed animals.Partial cartilage repaired tissue in Group C was taken,cryosectioned and stained with DAPI and BrdU immunofluorescence.Confocal laser scanning microscope was used to observe and count the cells.Specimens of the three groups were analyzed through gross observation and histological staining,and scored according to the international cartilage repair society (ICRS) gross morphological score and ICRS histological score.Results Laser scanning confocal microscopy showed (97.3 ± 2.6) ％ of the cells were derived from the implanted BMSCs in repaired tissue and that the ratio of these cells with proliferative capacity was (76.6 ± 2.5) ％.Gross observation suggested most of the cartilage defect areas in Group C were filled with ivory tissue,but those in Group A and B were still obvious depression.Histological staining showed the cartilage defect areas in Group C were filled with cartilage like tissue,which was well integrated with the surrounding normal cartilage,presented a few cartilage lacunas could be seen,and had contents of Col Ⅱ and glycosaminoglycan similar with the adjacent normal cartilage.There was almost no filler in the defect area in Group A.There was little fibrous tissue in the defect area in Group B.ICRS gross score was (8.3 ± 1.0) points in Group C,higher than that in Group A [(0.5 ± 0.6) points] and Group B [(2.3 ± 0.5) points] (P ＜ 0.05).ICRS histological score was (10.3 ± 2.4) points in Group C,higher than that in Group A [(0.5 ± 0.6) points] and Group B [(4.5 ± 1.0) points] (P ＜ 0.05).Conclusions BMSCs combined with Col Ⅱ-HA-OCS biomimetic hydrogel for repairing porcine articular cartilage defects can achieve satisfactory results.Implanted BMSCs are the main component of the cell composition in the repaired tissue and gradually differentiated into chondrocytes.

With the increasing prevalence of total knee arthroplasty (TKA), there is a corresponding rise in the number of patients requiring revision of total knee arthroplasty (R-TKA) for various reasons. R-TKA presents several complex challenges, with severe bone defect reconstruction being a critical obstacle to securing favorable long-term outcomes. Recently, the approach to managing bone defects has seen significant advancements, with a range of techniques proposed contingent on the defect's size and location. Severe bone defects require reconstruction with autologous or allogeneic bone grafts or metal fillers. However, bone grafts have their usage constrained by limited availability, risks of resorption and collapse, and the potential for disease transmission. Consequently, metal fillers have received widespread attention in practical applications due to their advantages, such as comprehensive source, customizability, and safety. The advantages of metal augment are that they provide immediate support without reinforcement and are not subject to necrosis and resorptive collapse. However, the difference in elastic modulus between metal and bone may lead to stress shielding and increase the risk of potential bone loss. Both Cone and Sleeve can achieve biological fixation of metaphyseal bone; however, in cases of periprosthetic infections, it is generally difficult to remove them easily due to the prosthetic bone in-growth and osseointegration. This study aims to provide a comprehensive review of the use of metal fillers to reconstruct bone defects during R-TKA. It is intended to aid orthopedic surgeons in understanding the spectrum of reconstructive possibilities and provide high-performance revision strategies for their patients.

Objective:To explore the clinical application value of pre-breathing mode in double-low imaging of 320-slices computed tomography(CT)for pulmonary artery.Methods:A total of 100 patients who underwent CT pulmonary angiography(CTPA)for suspected pulmonary embolism(PE)in Liuzhou People's Hospital from July 2021 to September 2022 were prospectively selected as the research subjects and they were randomly divided into observation group and control group,with 50 cases in each group.The patients of the control group adopted conventional breathing mode(the breathing password was activated after reaching the threshold,and the scan was triggered after 6 s),while the patients of the observation group adopted the pre-breathing mode(the breathing password was activated after 1 or 2 seconds,and the scan was triggered after reaching the threshold).Both two groups adopted double low-technique scan of 320 slices CT.The differences in delay time,radiation dose,the points of subjective and objective image quality,and other indicators were compared between the two groups.Results:The volume CT dose index(CTDIvol),dose length product(DLP),effective dose(ED)and delay time of the observation group were significantly lower than those of the control group(t=76.230,30.225,12.282,7.088,P<0.05),respectively.The comparison of the subjective points of image qualities between the two groups indicated that there were 25 cases with 5 points,23 cases with 4 points and 2 cases with 3 points in the observation group,and there were 21 cases with 5 points,26 cases with 4 points and 3 cases with 3 points in the control group.There was no significant difference in the averagely subjective points of image qualities between two groups(P>0.05).The signal-to-noise ratio(SNR)and signal to noise ratio(CNR)of the observation group were significantly lower than those of the control group,and the noise level(SD)of the observation group was significantly higher than that of the control group(t=25.441,23.886、11.426,P<0.05),respectively.The CT values of the artery trunk of right pulmonary,artery branch of right pulmonary,artery trunk of left pulmonary and artery branch of left pulmonary in the observation group were significantly higher than those in the control group(t=2.256,2.225,2.042,2.277,P<0.05),respectively.Conclusion:The pre-breathing mode can effectively improve CTPA image quality,and reduce radiation dose and the dosage of contrast agent,which clinical application effect is significant.It is worth learning.

ObjectiveTo understand the cooperative work and mechanism in the corona virus disease 2019 containment action by the support-to-Hebei epidemiological investigation group formed by five provinces， summarize the existing challenges， and discuss the relevant mechanism， so as to provide evidence for future support actions. MethodsA questionnaire survey was used to investigate the members from five provinces of the support-to-Hebei epidemiological investigation team. The content included basic information， work situation， problems in cooperative work， and suggestions in support mechanisms. ResultsA total of 104 questionnaires were issued， of which 101 valid questionnaires were collected with an effective response rate of 97.12%. The proportions of respondents who participated in the epidemic-related data preparation， case investigation， technical training， supervision of key venues， and specimen collection was 93.07%， 85.15%， 81.19%， 65.35%， and 44.55%， respectively. The respondents believed that information sharing channel of local epidemic situation was blocked （95.05%）， coordination mechanism among local departments was insufficient （84.16%）， communication and coordination mechanism among the dispatch institutions， support team， and local departments was unperfect （84.16%）， management of the dispatch institutions to the support team was relatively loose （79.21%）， dispatch institutions failed to make full use of professional advantages of the support team （72.28%）， and majority of the support team members engaged in a single profession （59.41%）. The respondents suggested that local departments should improve the information sharing mechanism （95.05%）， strengthen communication and coordination among the dispatch institutions， support team， and local departments （92.08%）， and dispatch institutions should clarify the tasks and responsibilities of the support team （91.09%）， formulate cross-regional emergency support plans （87.13%） and evaluation plans of support action （72.28%）. ConclusionIn order to ensure the efficiency and accuracy of future support actions， it is necessary to improve the mechanism of emergency coordination， communication and matching， response procedures， team management， and support evaluation.

BACKGROUND: Synovectomy has been introduced into total knee arthroplasty (TKA) with the aim of relieving pain and inflammation of the synovium. However, there are no long-term, comparative data to evaluate the effect of synovectomy in TKA. This study was aimed at assessing pain, function, and complications in patients undergoing synovectomy during TKA for osteoarthritis (OA) at long-term follow-up. METHODS: This was a prospective randomized controlled trial of 42 consecutive patients who underwent staged bilateral TKA. Patients undergoing the first-side TKA were allocated to receive TKA with or without synovectomy followed by a 3-month washout period and crossover to the other strategy for the opposite-side TKA. The overall efficacy of both strategies was evaluated by determination of blood loss, the Knee Society score (KSS), and knee inflammation conditions during a 3-month postoperative period. The postoperative pain, range of motion (ROM), and complications were sequentially evaluated to compare the two groups until 10 years after surgery. RESULTS: At the 10-year follow-up, both groups had a similarly significantly improved ROM (114.88 ± 9.84° vs. 114.02 ± 9.43°, t  = 0.221, P  = 0.815) and pain relief with no differences between the two groups (1.0 [1.0] vs. 1.0 [1.5], U  = 789.500, P  = 0.613). Similar changes in total blood loss, KSS, and knee inflammation were found in both groups during 3 months postoperatively ( P  > 0.05). Additionally, there was no significant difference regarding complications and satisfaction between the two groups ( P  > 0.05). CONCLUSIONS: Synovectomy in conjunction with TKA for primary OA does not seem to provide any benefit regarding postoperative pain, ROM, and satisfaction during a 10-year follow-up. In addition, it may not result in more blood loss and increased incidence of long-term complications. Based on our long-term findings, it should not be performed routinely. TRIAL REGISTRATION Chinese Clinical Trial Registry, ChiCTR-INR-16008245; https://www.chictr.org.cn/showproj.aspx?proj=13334 .
Humans ; Arthroplasty, Replacement, Knee/methods* ; Synovectomy/methods* ; Osteoarthritis, Knee/surgery* ; Prospective Studies ; Pain, Postoperative ; Inflammation/etiology* ; Range of Motion, Articular ; Knee Joint/surgery* ; Treatment Outcome ; Knee Prosthesis/adverse effects*