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Objective:Observing the effect of exosomes derived from hypoxic Bone marrow mesenchymal stem cells (BMSCs) on the function of chondrocytes, and exploring the role and mechanism of exosomal miR-196b-5p. Evaluating the application prospects of hypoxic BMSCs exosomes and miR-196b-5p for cartilage regeneration.Methods:Chondrocytes were cultured in the supernatant of BMSCs cultured under normoxia or hypoxia, respectively. The proliferation of chondrocytes was detected by CCK-8 assay and the expressions of Collagen type 2 (Col2), Col1, Aggrecan and SOX9 were detected by qPCR to evaluate the effect of hypoxic BMSCs paracrine on chondrocyte functions. Obtaining normoxic and hypoxic exosomes through ultracentrifugation, and testing their effects on the proliferation and anabolic-related genes of chondrocytes through CCK-8 assay and qPCR. Verifying the expression of miR-196b-5p in hypoxic exosomes based on exosomal miRNA array. Knocking out miR-196b-5p in hypoxic BMSCs, and detecting the effect of hypoxic exosomal miR-196b-5p on the functions of chondrocytes by loss-of-function assay. Predicting the downstream of miR-196b-5p through bioinformatics tools, and exploring the mechanism of hypoxic exosomal miR-196b-5p by gain-of-function assays. Hypoxic exosomes and miR-196b-5p-knockout hypoxic exosomes were loaded on silk fibroin hydrogel and subcutaneously into nude mice. After 4 weeks of culture, histological staining of saffron O, Masson and biochemical content of sGAG and collagen were performed to assess the application prospect of hypoxic exosomes and hypoxic exosomal miR-196b-5p on cartilage regeneration. Results:The results of CCK-8 assay and qPCR indicated that the supernatant of hypoxic BMSCs significantly promoted the proliferation of chondrocytes 1.20±0.07 and the expression of cartilage-related markers (Col2 2.95±0.17, Aggrecan 2.45±0.27, SOX9 2.92±0.29) compared to normoxic BMSCs (0.94±0.04, 1.89±0.09, 1.67±0.21, 1.76±0.16), the differences were statistically significant ( P<0.05). The result of CCK-8 assay showed that hypoxic exosomes (1.28±0.04) promoted the proliferation of chondrocytes compared to normoxic exosomes 1.05±0.06, the differences were statistically significant ( P<0.05). CCK-8 assay revealed that the down-regulation of miR-196b-5p in hypoxic exosomes 0.99±0.06 attenuated the proliferation of chondrocytes compared to control group 1.20±0.07, the differences were statistically significant ( P<0.05); the expression of Col2 0.56±0.04, Aggrecan 0.74±0.09, and SOX9 0.45±0.05 in chondrocytes was reduced in the miR-196b-5p knockdown group compared to the control group (1.00±0.09, 1.00±0.12, 1.00±0.07), the differences were statistically significant ( P<0.05). Co-transfection of pmirGLO-BACH1-WT reporter vector with miR-196b-5p mimics decreased the luciferase activity 0.73±0.06, the differences were statistically significant ( P<0.05). Co-transfection of pmirGLO-BACH1-MUT reporter vector with miR-196b-5p mimics showed no change in luciferase activity. BACH1 is the target of miR-196b-5p. Subcutaneous culture in nude mice showed that hypoxic exosomes significantly promoted the deposition of sGAG 383.2±21.54 and collagen 67.40±3.45, while reducing the expression of miR-196b-5p in hypoxic exosomes weakened the deposition of sGAG 258.4±19.50 and collagen 57.15±4.95, the differences were statistically significant ( P<0.05). Conclusion:Hypoxic exosomes promoted the functions of chondrocytes by inhibiting the expression of BACH1 through miR-196b-5p. Hypoxic exosomes can be applied in cartilage regeneration.
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Objective:To analyze the effect of patellar tilt angle on postoperative outcomes after total knee arthroplasty (TKA) without patella resurfacing.Methods:A total of 143 patients with end-stage knee osteoarthritis who underwent TKA without patellar replacement in the First Affiliated Hospital of Nanjing Medical University from October 2020 to October 2021 were retrospectively analyzed. There were 32 males and 111 females, aged 68.44±6.79 years (range, 52-86 years). Patients were divided into three groups according to the postoperative patellar tilt angle: tilt angle<5° was the mild tilt group (97 cases), 5°≤tilt angle<10° was the moderate tilt group (31 cases), and tilt angle≥10° was the severe tilt group (15 cases). All patients were followed up in the outpatient clinic at 3, 6 and 12 months after surgery, and knee visual analogue score (VAS), Hospital for Special Surgery (HSS) score and patella Feller score were observed and recorded to compare the postoperative knee pain and function of patients in different patella tilt groups.Results:All patients were followed up for 1.16±0.23 years (range, 1.0-2.0 years). There was no significant difference in baseline data between the groups. There were significant differences in the intra-group comparison of the VAS score before and after surgery among the three groups ( F=51.12, P<0.001; F=36.90, P<0.001; F=15.76, P<0.001). The VAS scores at 3, 6 and 12 months after operation were significantly lower than those before operation ( P<0.05). The knee VAS of the severe group was higher than that of the mild and moderate groups at 3, 6 and 12 months after surgery, and the difference was statistically significant ( P<0.05). There were statistically significant differences in knee HSS scores before and after surgery among the three groups ( F=81.12, P<0.001; F=36.05, P<0.001; F=32.93, P<0.001). The knee HSS scores at 3, 6 and 12 months after surgery were higher than those before surgery, and the difference was statistically significant ( P<0.05). The knee HSS scores of the severe tilt group at 3, 6 and 12 months after surgery were lower than those of the mild and moderate groups, and the difference was statistically significant ( P<0.05). There were statistically significant differences in the intra-group comparison of the patella Feller score before and after surgery among the three groups ( F=88.81, P<0.001; F=49.59, P<0.001; F=37.40, P<0.001). The patellar Feller score at 3, 6 and 12 months after surgery was higher than that before surgery, and the difference was statistically significant ( P<0.05). The patellar Feller score of the severe group at 3, 6 and 12 months after surgery was lower than that of the mild and moderate groups, and the difference was statistically significant ( P<0.05). Conclusion:Patellar tilt angle after TKA without patellar resurfacing will increase knee pain and limit joint function.
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Objective:A new type of bio-ink and polycaprolactone (PCL) were used to construct an integrated osteochon-dral composite tissue block by multi-nozzle 3D bioprinter. And the repair results to osteochondral defects were evaluated.Methods:In freeze-drying group: Freeze-dried composite scaffold made by silk fibroin (SF) and β-tricalcium phosphate was used to repair osteochondral defects, as control. In the 3D printing group: PCL was used to printed a hollow multi-layer cylinder frame by 3D biological printer. Extracellular matrix, SF and bone marrow mesenchymal stem cells were used as chondral bio-ink. Then, chon-dral bio-ink was used to print tissue-engineered cartilage on top of PCL frame. Before implantation of cartilage defect, autogenous cancellous bone was filled in PCL frame, then the tissue-engineered osteochondral composite was used to repair osteochondral defects. In mosaic group: Autologous osteochondral transplantation was performed. The repair results of the above three groups were compared by histological score, biochemical analysis and biomechanical test to evaluate the effect of repairing rabbit cartilage defects.Results:The compression modulus of neo-cartilage in the 3D print group 2.56±0.30 MPa was close to that of the mosaic group 2.51±0.13 MPa ( P>0.05), and significantly higher than that of freeze-dried group 1.37±0.14 MPa ( F=11.058, P<0.05). The sGAG contents in the 3D print group 14.49±0.7 μg/mg was close to that of the mosaic group 14.98±0.81 μg/mg ( P>0.05), and significantly higher than that of freeze-dried group 8.72±0.73 μg/mg ( F=20.973, P<0.05). However, there was no significant difference in collagen content between the three groups ( P>0.05). The results of ICRS cartilage repair histology score showed that the scores of the 3D print group were close to those of the mosaic group in the matrix, cell distribution, cell viability and subchondral bone ( P>0.05), and were significantly higher than those of freeze-dried group in the surface and cartilage mineralization scores ( F=19.544, P<0.05). Conclusion:Using the new bio-ink to make bone cartilage composite scaffold by 3D bio printing can simplify the construction of tissue-engineered bone cartilage composite tissue in vitro, and can repair cartilage defects in vivo.
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Objective:To observe the expression of microRNA (miRNA, miR)-5787 in breast cancer tissues and various cell lines, analyze the effect of overexpression of miR-5787 on breast cancer cell invasion and proliferation, and explore its possible molecular mechanism.Methods:Real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) method was used to detect the expression of miR-5787 in 47 breast cancer tissues and adjacent tissues, 4 breast cancer cell lines and normal breast epithelial cells. Breast cancer cell lines with the lowest miR-5787 expression were selected and transfected with miR-5787 mimics (experimental group) and control NC mimics (control group), respectively. qRT-PCR was used to detect the expression of miR-5787 in cells of the two groups. Transwell invasion experiment and cell counting kit-8 (CCK-8) were used to detect the effect of miR-5787 overexpression on breast cancer cell invasion and proliferation. Bioinformatics software and dual luciferase reporter gene experiments were used to predict and verify the target genes that miR-5787 could complementally bind. qRT-PCR and Western blot were used to detect the expression of target gene mRNA and protein.Results:Compared with adjacent tissues (5.05±0.82), the expression of miR-5787 in breast cancer tissues (1.32±0.33) was significantly reduced ( P<0.01). Compared with normal breast epithelial cells, the expression of miR-5787 in the four breast cancer cell lines was reduced ( P<0.05), and the expression in HCC1937 cells was the lowest ( P<0.01). After transfection of miR-5787 mimics, the expression of miR-5787 in HCC1937 cells in the experimental group was significantly higher than that in the control group ( P<0.01). Overexpression of miR-5787 could inhibit the invasion ( P<0.05) and proliferation ( P<0.05) of breast cancer HCC1937 cells. Bioinformatics software showed that the target gene of miR-5787 might be heparan sulfate proteoglycan 2 (HSPG2), and miR-5787 could complement HSPG2 mRNA ( P<0.01). qRT-PCR and Western blot indicated that overexpression of miR-5787 could significantly inhibit the expression of HSPG2 gene ( P<0.01), with the decreased expression of Vimentin, N-cadherin, Ki67 and PCNA. Conclusions:miR-5787 expression was low in breast cancer tissues and cell lines. Overexpression of miR-5787 could inhibit the invasion and proliferation of breast cancer HCC1937 cells by interfering with the expression of HSPG2 gene.
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OBJECTIVE@#To construct a three-dimensional (3D) finite element mechanical model of total hip arthroplasty for comparison of biomechanical differences of the hip joint following capsule repair and postoperative rehabilitation.@*METHODS@#Six frozen specimens of hip joint posterior capsule ligament complex were collected in a bone-capsule-bone manner, and the load-strain curve and other mechanical properties of the specimens were tested using a universal material testing machine. Thin-section CT data of the pelvis and lower limbs obtained from a volunteer were imported into Mimics software to construct a 3D model of the hip joint. Digital models of the cup, femoral prosthesis and joint capsule were created in CATIA software and imported into Mimics to simulate total hip arthroplasty; the assembled data were imported into ABAQUS software. The properties of the capsule were set according to results of the mechanical test, anatomical studies, and constitutive equations, and the biomechanics of the anatomically repaired and conventionally repaired capsules were compared during hip flexion.@*RESULTS@#The results of testing on the 6 capsule specimens showed a mean ultimate tensile strain of (39.21±5.23)% and a mean of ultimate tensile strength of 1.65±0.38 MPa. The stress-strain curve of the finite element model was consistent with the results of mechanical test on the specimens and the biochemical characteristics of the capsule. The stress was distributed evenly in the anatomically repaired capsule during hip flexion but not in the capsule repaired through the conventional approach; the tensile stress in the lower part of the conventionally repaired capsule reached the ultimate tensile stress measured on the capsule specimens at a 90° flexion.@*CONCLUSIONS@#The finite element model allows dynamic, quantitative and visual assessment of stress distribution in the hip joint capsule, and compared with the conventional approach, anatomical repair can achieve better biomechanical properties of the capsule.
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Humans , Arthroplasty, Replacement, Hip , Biomechanical Phenomena , Finite Element Analysis , Hip Joint/surgery , Prognosis , Stress, MechanicalABSTRACT
Objective To construct a new sustained-release system,hollow mesoporous silica nanoparticles (HMSNs),to control the release of ethylene diamine tetraacetic acid (EDTA) continuously,effectively and intelligently to treat the abnormal increase of metal ions in vivo.The disulfide bond can be broken or reconstructed with the change of H + concentration to realize the construction of "receptor",and the "valve system" is constructed by blocking cucurbituril and alpha-cyclodextrin through disulfide bond.Thus,the abnormal increase of chromium and cobalt ions in rats can be accurately controlled and maintained at normal levels.Methods HMSNs-EDTA sensitive to H+ was prepared.HMSNs containing functional groups of alpha-cyclodextrin were constructed.The disulfide bond was formed between the HS group at the end of cucurbituril and the HS group of alpha-cyclodextrin as a "switch".Cucurbituril and alpha-cyclodextrin are connected by disulfide bond to form a valve system,which can block silica channels and thus close EDTA.A rat model of elevated chromium and cobalt ions was established by intraarticular injection of CoCrMo nanoparticles suspension into the knee joint.Rat models were randomly divided into three groups:intraperitoneal injection of saline (control group),intraperitoneal injection of traditional "valve system" drug sustained release (IgG-HMSNs-EDTA group),and intraperitoneal injection of H+ sensitive cucurbituril-HMSNs-EDTA sustained release (intelligent sustained release system group).During this process,nanoparticle suspension was injected continuously to observe the changes of serum chromium and cobalt concentration in rats.Results From the release curve of EDTA,it was found that the higher the concentration of H + was,the faster the drug release was (H+ concentration group:2 mmol/L ＞ 1 mmol/L ＞ 0.5 mmol/L ＞ 0.1 mmol/L).It shows that the sensor does control the valve with the change of H+ concentration.Compared with the slow-release body without valve,the release of EDTA in the new intelligent slow-release body is gentler.Within 20 weeks,the concentration of metal ions in the control group increased continuously and slowly due to the absence of EDTA treatment (Chromium 1.08±0.07 ug/L and cobalt 41.14±0.79 ug/L).In the traditional valve group,the metal ions decreased rapidly within 8 weeks and were once lower than the normal values in rats.Subsequently,due to the release of EDTA,metal ions will still increase abnormally (Chromium ion 0.61 ±0.52 ug/L,cobalt ion 28.72± 16.93 ug/L).The intelligent sustained-release system group can more effectively,continuously and accurately control the abnormal changes of chromium and cobalt ions in vivo,and the difference is statistically significant (Chromium ion 0.65±0.13 ug/L,cobalt ion 29.68±3.24 ug/L).Conclusion According to the principle that disulfide bond can be broken or reconstructed with the change of H+ concentration,the application of cucurbituril-HMSNs-EDTA intelligent microsphere sustained release system to treat patients with increased chromium and cobalt ions caused by plants in metal will control the drug release more accurately and intelligently.The intelligent sustained-release system can not only avoid the side effects caused by the rapid and excessive release of drugs,which lead to the disorder of normal trace metal elements in vivo,but also prolong the treatment time,and can maintain the chromium and cobalt ions in rats at normal levels for a long time.
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Objective To investigate the method and efficacy in treating acetabular bone defects by the use of titanium wire mesh and impact bone allograft in revision total hip arthroplasty.Methods Twenty-two patients (22 hips) with acetabular bone defects in revision total hip arthroplasty were treated with wire mesh and impact bone allograft from January 2008 to December 2013.There were 7 males and 15 females in the present study.The average age of the patients at the surgery was 64.8 (37-78) years.According to Paprosky classification,there were 9 cases of type ⅡA,4 cases of ⅡB,7 cases of ⅡC and 2 cases of ⅢB.Twenty cases with aseptic loosen and 2 with periprosthetic infection were underwent revision surgery.Deep frozen cancellous bone allograft was sterilized and morselized to particles with the size of 7 to 10 mm.After removal of loosed acetabular component,the bone grafts were impacted into the acetabular defects area to restore the bone quantity.Titanium wire mesh with appropriate diameter was chosen to fix on impacted bone graft and fixed acetabulum with screws.Polyethylene cup was cemented in the mesh wire with proper position.Harris hip score system was used to evaluate the hip joint function.The AP pelvis X-ray was taken at 1 week,3 months,12 months and annually thereafter postoperatively to evaluate the rotation center,fusion of the bone graft and loosening of cup.Results All patients were followed up with the average period 5.1 years (3-7 years).The average Harris hip score before revision was 43.75±13.45,while the score was 85.33±7.84 at last follow-up (t=7.930,P=0.000).The average height of hip rotation center of surgical side was 3.49±0.77 cm before surgery,while its height at last follow-up was 2.22±0.22 cm (t=4.390,P=0.005).The distance between hip rotation center and the base of acetabulum was 3.54±0.45 cm before surgery,while its value was 3.52± 0.76 cm at last follow-up.All the bone grafts came to infusion with the average time 12 months (9-15 months).There was no case with cup migration more than 4 mm or rotation greater than 5° at last follow-up.One patient had the symptom of sciatic nerve injury.No case was with infection or dislocation.Conclusion In the treatment of acetabular bone defects,wire mesh and impact bone allograft with cemented cup in revision total hip arthroplasty can reconstruct hip rotation center and the acetabular bone quantity effectively.Satisfied early-midterm curative effects could be acquired by using this method.
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Objective To compare the clinical safety and efficacy of simultaneous bilateral total knee arthroplasty (TKA) and staged bilateral TKA in treatment of both knee osteoarthritis.Methods A total of 119 patients (14 males,105 females) with both knee osteoarthritis who underwent TKA from March 2005 to March 2012 were retrospectively analyzed.Their ages ranged from 30 to 81 years with the average age of 65.23±6.33 years.The patients were divided into three groups according to different treaments:simultaneous bilateral TKA group,staged bilateral TKA group during the same hospitalization period and staged bilateral TKA group in two separate hospitalization periods.All the procedures were performed by the same surgeons and the same type of prostheses (LPS-Flex,Zimmer,US) were implanted.Differences of preoperative factors (age,height,body mass in dex and complications),treatment factors (preoperative hemoglobin,operation time,drainage volume,blood transfusion volume,total hospitalization time and total hospitalization costs) and postoperative curative effects (HSS scores,WOMAC scores and ROM)among three groups were compared.The analysis of viariace,LSD-t test and x2 test were used for data analysis.Results The differences of gender composition,body mass index,preoperative hemoglobin were not statistically significant among three groups (P＞0.05).The patientsin simultaneous bilateral TKA group were younger,and havelower incidence ofpreoperative complications (P＜0.05).The differences of post-operative HSS scores,WOMAC scores and ROM were not statistically significant among the three groups (P＞0.05).Although the total hospitalization time,operation time were shorter,and the hospitalization costs were significant ly lower in simultaneous bilateral TKA group,the total drainage volume,the total blood transfusion volume and incidence of postoperative complication rate were higher in this group than those of the other two grops (P＜0.05).Conclusion Due to great impact on patients' physiological conditions,more postoperative complication occurrence and high risk of periprosthetic infection,the decision of simultaneous bilateral TKA should be made cautiously.
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Objective To determine the incidence of avascular necrosis after closed reduction and cannulated compression screws fixation of intra-capsular femoral neck fracture and to investigate the multiple factors correlated to avascular femoral head necrosis.Methods All the patients of intra-capsular femoral neck fracture who accepted closed reduction and cannulated compression screws fixation between 2001 and 2010 in Jiangsu Province were reviewed in multi-centers retrospectively.The multiple factors were analyzed including age,gender,affected side,mechanism of injury,fracture classification,procedure delay,quality of reduction,time of full-weight-bearing,configuration of the screws and removal of the screws.Multiple correlation factors were analyzed with SPSS 13.0 statistic system.Results Complete case records were documented in 1849 cases who were followed up for an average 6.5±2.7 years (range,2-10 years).Avascular necrosis occurred in 246 cases (13.3％).The average time of diagnosis of avascular necrosis was 17±4.6months (range,8-72 months) after injury.The average Harris score of the hips which didn't develop to avascular necrosis was 93.8±8.9 (range,78～100) at the last follow up.Multiple correlation factors analysis indicated that displacement degrees of fracture and the quality of reduction were significantly correlated to the incidence of avascular necrosis (OR=2.078,3.423).Conclusion Closed reduction and cannulated compression screws fixation after the intra-capsular femoral neck fracture can get satisfactory results.Displacement degrees of fracture and the quality of reduction are significantly correlated to the incidence of avascular femoral head necrosis.
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Objective To compare the serum metal ion levels and host immunologic response of patients received non-modular,large-head metal-on-metal total hip arthroplasty (THA,Durom) with those received modular titanium acetabular component (Trilogy) using conventional head sizes and metal-on-highly cross-linked polyethylene articulations at mean 2-year follow-up interval.Methods A continuous series of 32 consecutive patients (32 hips) accepted THA with a Durom large head metal-on-metal articulation between January 2008 and December 2010 was as study group (Durom Group).From all the patients who received THA with Trilogy prosthesis at the same period,32 patients matched the Durom group in age,gender and body mass index (BMI) were chosen to form the Trilogy group.Another 32 healthy volunteers also matched the Durom group were chosen to form the control group.At the final follow-up,the serum metal ion levels,host immunologic response were evaluated.Results The mean follow-up time for Durom group was 24.9 months (range,15-34 months) compared to 25.53 months (range,15-48 months) for Trilogy group.Co and Cr levels in Durom group were 4.33 and 1.95 times as high as those in Trilogy group.There was no statistically significant difference in serum C3,C4,IgA,IgG,IgM value in three groups.CD3+,CD4+ and CD8+cells in Durom group decreased significantly compared with Trilogy and control groups.The interferon-γ(IFN-γ) level in Durom group was significantly higher than that in Trilogy and control groups.Conclusion The serum cobalt and chromium levels in patients received Durom metal-on-metal THA elevated significantly in early period.Meanwhile,some amount of impact on host cell mediated immunity occurred.
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Objective To evaluate effect of two-stage exchange total hip arthroplasty (THA) using an antibiotic-loaded cement spacer in the treatment of hip infection secondary to hip surgery.Methods From January 2005 to January 2010,6 consecutive patients with infected hip secondary to hip surgery,including 2 males and 4 females,aged from 43 to 68 years (average,59.7±9.2 years) were treated with two-stage exchange THA.There were 3 cases of femoral neck fracture treated with compression screws fixation,1 case of femoral head necrosis treated with bone graft,and 2 cases of early stage femoral head necrosis treated with core decompression and local interventional therapy respectively.Debridement and insertion of antibioticloaded cement spacer was performed in the first stage.After eradication of infection,it was converted to THA in the second stage.All patients were followed up regularly.Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were tested.Harris score was used to evaluate the function of the hips.Results All patients were followed up for an average of 46 months (range,24 to 81 mouths).Five of 6 patients were successfully converted to THA after an average of 14 weeks.One patient accepted the second debridement and reinsertion of a spacer owing to the abnormal values of ESR and CRP; this case was converted to THA successfully 12 weeks after the second debridement.Harris hip score improved from preoperative 35.6±3.3 to 57.8±5.4 between the two stages and 92.3±5.7 at final follow-up.One patient suffered deep vein thrombosis in the infected extremity and pulmonary embolism.There was no reinfection after THA.Conclusion Twostage exchange THA using an antibiotic-loaded cement spacer can obtain satisfactory results for the treatment of hip infection secondary to the hip surgery.
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ObjectiveTo explore the magnitude of the deformation of Durom cup after press-fit implantation in cadaver models and to investigate which part of the cup would deform the most.Methods Three fresh adult cadaver pelves were harvested and were cleaned of soft tissue,preserving the sacrospinous and sacrotuberous ligaments.Bilateral acetabular replacements in all cadaver pelves were performed by a senior surgeon.All acetabulums were reamed with corresponding reamers,and the direction of reaming was 40°to 45° of abduction and 15° to 20° of anteversion.Larger reamers were used sequentially until the anterior and posterior walls were firmly engaged.Six Durom cups were implanted.The deformation of each cup was detected by 3D Digital Image Correlation (3D DIC) method,and the magnitude and the parts of the deformation were recorded.ResultsThe diameters of cups were 50 mm in 2,52 mm in 2 and 54 mm in 2,respectively.All cups generated different degree of deformation,which were mostly located in the posterior-superior quadrant and the areas of the ramus of ischium.After measuring the maximum deformed areas for three times,it was found that the localized depression deformation occurred in all cups.The average deformation value was (41.73±8.86) μm (range,29.91-49.43 μm).There was no significant change in deformation value 24 hours after press-fit implantation and 7 days after removing the cups.ConclusionDurom large diameter metal acetabular component will generate deformation during the press-fit implantation.And the deformation may play an important role in more wear and more ions release.
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Objective To evaluate mortality associated with simultaneous bilateral or staged bilateral TKA, and better understand the risks involved in the simultaneous versus staged bilateral procedures.Methods A systematic review was conducted, following an a priori protocol, according to the methods recommended by the Cochrane Musculoskeletal Group in the Cochrane Collaboration. Eligible studies were identified in PubMed (1990-2010), OVID MEDLINE (1990-2010), and the Cochrane library, concerning postoperative complications of bilateral or staged bilateral total knee arthroplasty. All of the English-language abstracts were obtained, and retrieval words including bilateral total knee arthroplasty, staged total knee arthroplasty, and total knee arthroplasty, etc. An extensive analysis was then performed to identify articles fulfilling the inclusion criteria for the study. The details of the reported data were extracted and evaluated by two reviewers independently. Data analyses were conducted with Stata 10.0. Results Six studies met our inclusion criteria for review. The combined results showed that the prevalence of mortality[OR=2.925, 95% CI (2.352, 3.638)], mortality 30 days postoperatively[OR=5.078, 95% CI (2.192, 1 1.763)]and mortality in 70 years or older patients[OR=4.087, 95% CI (1.947, 8.582)]were statistically higher in the population that had undergone simultaneous TKA compared with staged TKA. Conclusion Compared with staged bilateral TKA, simultaneous bilateral TKA might carries a higher potential risk of postoperative mortality. Patients should be aware of this information when deciding whether to proceed with simultaneous bilateral TKA. Further well-designed and large-scale randomized controlled trials are required to confirm these findings.
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Objective To explore the effects of co-culture of chondrocytes and bone mesenchymal stem cells (BMSCs) on constructing engineered cartilages, and confirm the most suitable ratio of chondrocytes to BMSCs. Methods Chondrocytes and BMSCs were isolated from articulars cartilages of rabbit (1 month old)cells (40 μl 4×107/ml) were seeded into a poly(lactic-co-glycolic acid) (PLGA) scaffold and cultured statically for 2 days. They were transferred into the cyclic pressures system, and cultured under cyclic pressures for 3 weeks. The engineered cartilages were harvested and examined by gross observation, histological staining, immunohistochemisty of collagen Ⅱ, the content of glyeosaminoglycans, GAGs, DNA and the percentage of collagen Ⅱ dyeing area. Results The engineered cartilages of the co-cultured groups grew bigger than those of the chondrocytes alone group, and their surfaces were smooth and glossy. The distributions of cartilaginous extracellular matrices in the co-cultured groups were more homogenous than those of the chondrocytes alone group.gen Ⅱ dyeing area of the co-cultured groups were higher than those of the chondrocytes alone group. The conConclusion Co-culture of chondrocytes and BMSCs could improve the quality of engineered cartilages. The
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0.05). Conclusion It appears that early fixation of long bone fractures with intramedullary nail has little influence on pulmonary blood dynamics.