ObjectiveTo explore the feasibility of establishment of a artificial joint aseptic loosening mouse model by cobalt-chromium particles stimulation.MethodsTwenty-four 8-week-old male severe combined immunodeficient (SCID) mice were divided into experimental group (n=12) and control group (n=12). The titanium nail was inserted into the tibial medullary cavity of mouse in the two groups to simulate artificial joint prosthesis replacement. And the cobalt-chromium particles were injected into the tibial medullary cavity of mouse in experimental group. The survival of the mouse was observed after operation; the position of the titanium nail and the bone mineral density of proximal femur were observed by X-ray film, CT, and Micro-CT bone scanning; and the degree of dissolution of the bone tissue around the tibia was detected by biomechanical test and histological staining.ResultsTwo mice in experimental group died, and the rest of the mice survived until the experiment was completed. Postoperative imaging examination showed that there was no obvious displacement of titanium nails in control group, and there were new callus around the titanium nails. In experimental group, there was obvious osteolysis around the titanium nails. The bone mineral density of the proximal tibia was 91.25%±0.67%, and the maximum shear force at the tibial nail-bone interface was (5.93±0.85) N in experimental group, which were significantly lower than those in control group [102.07%±1.87% and (16.76±3.09) N] (t=5.462, P=0.041; t=3.760, P=0.046). Histological observation showed that a large number of inflammatory cells could be seen around the titanium nails in experimental group, while there was no inflammatory cells, and obvious bone tissue formation was observed in control group.ConclusionThe artificial joint aseptic loosening mouse model can be successfully established by cobalt-chromium particles stimulation.
Objective To evaluate the mechanisms of p42/p44 kinase phosphorylation in cell models and to investigate the effect of simvastatin on the prevention and treatment of aseptic loosening of prosthesis by observing the influence of simvastatin on the levels of tumor necrosis factor α (TNF-α) and monocyte chemoattractant protein 1 (MCP-1) of human peri pheral blood mononuclear cell (PBMC) challenged with titanium particles. Methods PBMC from 45 mL peripheral blood of healthy adult voluntary donators, were separated and cultured, and divided into 5 groups according to different culturemedium: group A, PBMC and titanium particles; group B, PBMC and titanium particles with 1 × 10-5 mol/L simvastatin; group C, PBMC and titanium particles with 1 × 10-6 mol/L simvastatin; group D, PBMC and titanium particles with 1 × 10-7 mol/L simvastatin; and group E, PBMC and titanium particles with the extracellular signal-regulated kinase (ERK1/2) inhibitor U0126. The contents of TNF-α and MCP-1 were tested by ELISA after 24 hours of culture. PBMC were pretreated with different medium grouping as groups A, B, C, D, and E for 60 minutes, and were challenged with titanium particles for 30 minutes and 60 minutes, then the level of ERK1/2 expression was tested by Western blot. Results In groups A, B, C, D, and E, the absorbance (A) values of TNF-α were 1.115 5 ± 0.243 6, 0.693 6 ± 0.354 3, 0.695 7 ± 0.387 3, 0.716 4 ± 0.478 9, and 0.263 5 ± 0.101 6, respectively; and the A values of MCP-1 were 1.421 0 ± 0.105 3, 0.915 1 ± 0.411 3, 1.003 5 ± 0.464 2, 1.102 0 ± 0.353 9, and 0.271 3 ± 0.145 1, respectively. The levels of TNF-α and MCP-1 in group A were significantly higher than others, showing significant differences (P lt; 0.05). There were significant differences between group E and groups B, C, and D (P lt; 0.05), between group B and groups C, D (P lt; 0.05); no significant difference between group C and group D (P gt; 0.05). Western blot results showed the expression of ERK1/2 in all groups at 30 minutes and 60 minutes of culture. The levels of ERK1/2 expression were 1.612 1 ± 0.068 2, 1.078 1 ± 0.072 8, 1.268 7 ± 0.223 1, 1.439 7 ± 0.180 1, and 0.732 0 ± 0.110 4 in groups A, B, C, D, and E, respectively; showing significant differences between groups (P lt; 0.05). Conclusion ERK1/2 is a phosphorylated protein after stimulated by wear particles; it is also one of the most important cell signal ing activation of macrophage. Simvastatin can inhibit the expression of bone absorptive factors induced by wear particles and may be used in the prevention and treatment of aseptic loosening of prosthesis.
Objective To demonstrate the anatomical and biomechanical basis of scaphoid ring sign in advanced Kienbock’s disease. Methods The study consisted of two sections. The ligaments stabilizing the proximal pole of the scaphoid were observed in 5 specimens. Under 12 kg dead weight load through the tendons of the flexion carpal radial, the flexion carpal ulnar, the extension carpal radial, and the extension carpal ulnar for 5 minutes, the stresses of the scaphoid fossa and lunate fossa were measured in the case of neutral, flexion, extension, radial deviation and ulnar deviation of the wrist joint under normal and rupture conditions respectively by FUJI prescale film and FPD-305E,306E.Results Based on anatomical study, the ligaments stabilizing the proximal pole of the scaphoid consisted of the radioscaphocapitate ligament, long radiolunate ligament and scapholunate interosseous ligament; and the latter two ligaments restricted dorsal subluxation of the proximalpole of the scaphoid. When compared rupture condition with normal condition, thescaphoid fassa stress of radial subregion was not significantly different (0.90±0.43 vs 0.85±0.15), and the ones of palmar, ulnar and dorsal subregions decreased (0.59±0.20, 0.52±0.05 and 0.58±0.23 vs 0.77±0.13, 0.75±0.08 and0.68±0.09) in the case of extension; the scaphoid fassa stresses of all subregions increased or had no difference in the case of neural, flexion, radial deviation and ulnar deviation. The lunate fossa stresses of all subregions increased in thecase of neural, and the ones of all subregions decreased or had no difference inthe case of flexion, extension, radial deviation and ulnar deviation.Conclusion Rotary scaphoid subluxation should be treated operatively at Ⅲ B stage of Kienbock’s disease to avoid traumatic arthritis of theradioscaphoid joint.
Objective To introduce the occurrence mechanisms, prevention, and treatment measures of prosthetic aseptic loosening. Methods The recent original articles about prosthetic aseptic loosening were extensively reviewed and analyzed. Results Prosthetic aseptic loosening was a very complex process involving many mechanical and biological aspects. The main mechanical factors included prosthetic materials, shapes and sizes, implant fixation methods (including surfacetreatments), cl inical installation, interface micromotion, stress shielding, implant wear, interface integrity, and peri prosthetic high hydraulic pressure, etc.; the main biological factors included the types and sizes of wear particles, cell-activated responses, cytokine release, enzyme activation and allergic reactions to wear particles, etc.. Many measures should be adopted to effectively prevent and treat it, including improving materials and designs of prostheses, fixation techniques, surgical techniques, and drug treatments. Conclusion Prosthetic aseptic loosening is still a troublesome compl ication after joint replacements in orthopaedics, and more attention should be paid for its effective prevention and treatment.
ObjectiveTo observe the vascularity in periprosthetic tissues of aseptic loosening after total hip arthroplasty (THA) and to explore the relationship between expression of vascularity and osteolysis. MethodsBetween October 2009 and June 2012, interface tissues were obtained from 22 patients (22 hips) who underwent revision of THA because of prosthetic aseptic loosening, including 12 males and 10 females with the age range of 53-81 years and prosthesis survival range of 6-14 years. The interface tissues were divided into osteolysis group and non-osteolysis group based on preoperative X-ray findings and intraoperative observation. The synovial tissues were harvested from another 8 patients (3 males and 5 females, aged 58-72 years) with osteoarthritis undergoing THA as control group. HE stainging was used to observe the histological character, and low-wear or high-wear was identified according to metal or polyethylene particles amount in osteolysis group. The CD34 immunohistochemical staining was used to mark the blood vessels. Microvessel density and microvessel index were calculated with the use of image analysis software. ResultsHistological observation showed that wear particles and numerous macrophages/multinucleated giant cells accumulated in the membrane of osteolysis group, while many fibroblasts and synovial cells existed in non-osteolysis group. The microvessels density and microvessel index were significantly lower in non-osteolysis group than those in osteolysis group and control group (P＜0.05), and there was no significant difference in microvessel density and microvessel index between osteolysis group and control group (P>0.05). There were less microvessel density and microvessel index in heavy-loaded metal or polyethylene wear particles areas than those in low-loaded metal or polyethylene wear particles areas (P＜0.05), and there was no significant difference in microvessel index and microvessel index between low-wear group and high-wear group for either polyethylene or metal particles (P>0.05). ConclusionThe phagocytosis of macrophage in periprosthetic tissues need vicinal microvessels formation and blood supply to some extent. Vascular injury and decreased blood supply at the implant-bone interface seem to be one of the reasons for insufficient implant osseointegration and aseptic loosening.
Objective To observe the expressions of extracellular matrix metalloproteinase inducer (EMMPRIN) and matrix metalloproteinase 9 (MMP-9) around the prosthesis, and to study the relationship between the expressions of EMMPRIN and MMP-9 and osteolysis around prosthesis. Methods Interface tissues were obtained at three Delee-Charnley acetabular sections and seven Gruen femur sections from 8 cases (8 hips) undergoing revision after total hip arthroplasty between February 2010 and January 2012, and were divided into osteolysis group and non-osteolysis group based on preoperative X-ray film and intraoperative observation; the tissues from another 8 patients with osteoarthritis undergoing total hip arthroplasty as the control group. The immunohistochemical staining and RT-PCR assays were used to determine the expressions of EMMPRIN and MMP- 9. The correlation between the positive cells and the severity of osteolysis were analyzed and compared. Results Histological examination showed that many macrophages, multinucleated giant cells assembled in the membrane of osteolysis zone, but many fibroblasts and synovial cells in non-osteolysis zones. EMMPRIN and MMP- 9 positive cells and gene expressions were observed in every group. The percentage of positive cells and gene expression of EMMPRIN and MMP-9 in osteolysis group were significantly higher than those in non-osteolysis and control groups (P lt; 0.05), but no significant difference was found between non-osteolysis group and control group (P gt; 0.05). The percentage of positive cells of EMMPRIN in zone III of acetabular was higher than that in zone I and zone II of revision hip (P lt; 0.05), but no significant difference between zone I and zone II (P gt; 0.05). The percentage of positive cells of MMP-9 in zone I and zone III was significantly higher than that in zone II of revision hip (P lt; 0.05), but no significant difference between zone I and zone III (P gt; 0.05). The expression of EMMPRIN from high to low in order was zones 1, 7, 4, 2, 3, 5, and 6 at femur; the values of zones 1, 7, and 4 were significantly higher than those of zones 2, 3, 5, and 6 (P lt; 0.05), but no significant difference among zones 1, 7, and 4, and among zones 2, 3, 5, and 6 (P gt; 0.05). The expression of MMP-9 from high to low in order was zones 1, 7, 4, 2, 3, 6, and 5 at femur; the values of zones 1 and 7 were significantly higher than those of zones 4, 2, 3, 6, and 5 (P lt; 0.05), and the values of zones 4 and 2 were significantly higher than those of zones 3, 6, and 5 (P lt; 0.05), but no significant difference between zone 1 and zone 7, between zone 4 and zone 2, and among zones 3, 5, and 6 (P gt; 0.05). Conclusion The expressions of EMMPRIN and MMP-9 have certain coherence. The over-expressions of EMMPRIN and MMP-9 may be one of the key points of inhibiting bone reconstruction and bone resorption at bone-implant interface under the stimulation of wear debris．
ObjectiveTo summarize the mechanism of neutrophil extracellular traps (NETs) in hepatic ischemia-reperfusion injury (HIRI) and the research progress in targeting NETs to reduce HIRI, providing valuable reference for reducing HIRI. MethodThe related literatures at home and abroad about the role of NETs in the pathogenesis of HIRI and target NETs to alleviate HIRI were retrieved and reviewed. ResultsHIRI usually appeared in the process of liver surgery and was a common clinical problem, which occured in situations such as liver surgery, organ transplantation, liver ischemia and so on. This kind of injury would lead to tissue necrosis, inflammatory response and oxidative stress, which was a major cause of hepatic dysfunction and multiple organ failure after hepatic surgery, greatly increases the complications and mortality after hepatic surgery. NETs played a crucial role in the aseptic inflammatory response induced by hepatic ischemia/reperfusion. During hepatic ischemia-reperfusion, neutrophils promoted inflammatory cascade reactions and cytokine storms by forming NETs, exacerbating damage caused by hepatic ischemia-reperfusion. At present, some experimental and clinical studies had shown that inhibiting the formation of NETs or eliminating the formed NETs could alleviate the hepatic ischemia-reperfusion injury and improve the prognosis. ConclusionsTargeting NETs may become a new method for treating hepatic ischemia-reperfusion injury. In the future, it is foreseeable that more experiments and clinical trials will be conducted on targeted NETs for the treatment of hepatic ischemia-reperfusion injury. And gradually establish more comprehensive and effective treatment strategies, thereby providing new ways to improve the prognosis of hepatic surgery patients in clinical practice.
Objective To observe the effect of local injection of vascular endothel ial growth factor (VEGF) and VEGF antibody on the wear particle-induced osteolysis in the mouse air pouch model and to investigate the role of VEGF in the process of aseptic loosening of prosthesis. Methods The stem of metal hip prosthesis was obtained from the revision surgery.Metallic wear particles were made by vacuum ball mill ing. Wear particles suspension was prepared into the concentration of 10 mg/mL with PBS. Fifty female Kunming mice (aged 8-10 weeks, weighing about 25 g) were selected. Of 50 mice, 10 were used as the donors of bone graft, the other 40 were equally divided into control group (group A), particle group (group B), VEGF group (group C), and VEGF inhibited group (group D). Air pouches were made on the back of 40 mice by injecting sterile air subcutaneously. At 8th day, a graft of calvaria from the donor mice was implanted in air pouch. In groups B, C, and D, 0.5 mL wear particles suspension was injected into the air pouches, and in group A, 0.5 mL PBS was injected. Once a day at 6th and 7th days during the air pouch preparation and one time every two days after bone implantation, 0.2 mL recombinant human VEGF (rhVEGF) and VEGF antibody (Bevacizumab) were injected into the air pouches in groups C and D, respectively. In group A and group B, 0.2 mL sal ine was injected. Pouch tissues and bone were harvested at 2 weeks after bone implantation for HE staining, real-time fluorescent quantitative PCR and ELISA analyses. Results All mice survived to the end of experiment. The gross observation showed that there were mild redness, swell ing, and less neovascularization in air pouches in group A. There were obvious redness, swell ing, and more exudative and neovascularization in groups B, C, and D, most obvious in group C, the next in group B, then in group D. The histological and molecular biological analysis showed that inflammatory responses and osteolysis were obvious in group B and the pouch membrane thickness, the cell density, transforming growth factor α, interleukin 1β, and VEGF were significantly higher than those in group A (P lt; 0.05). The inflammatory responses and osteolysis were mostobvious in group C and the above-mentioned indexes were significantly higher than those in group B (P lt; 0.05). There were some inflammatory responses and osteolysis in group D, but the indexes were significantly lower than those in group B (P lt; 0.05) and were significantly higher than those in group A (P lt; 0.05). Conclusion VEGF can promote inflammatory responses and osteolysis in aseptic loosening of prosthesis. VEGF antibody can effectively inhibit wear particle-induced osteolysis.
To observe the effect of different dosage of curcumin on expression of MMP-2 and MMP-9 in the tissue of cystiform in air-pouch mouse models after the injection of polyethylene wear particles, and to investigate its mechanism of intervening inflammatory response induced by wear particles. Methods Seventy-two kunming strain mice were used to establ ish air-pouch animal models by referring to the method of Yang et al. and injecting 3 mL suspension of ultrahigh molecular weight polyethylene wear particles (concentration 1 × 108 cells/mL) into dorsal cyst cavity. Then the animals were randomized into 3 groups (n=24 per group): group A (control group), 0.6 mL/day normal sal ine by gavage; group B(low-dosage experimental group), 0.6 mL/day curcumin solution at a concentration of 1.6 mg/mL by gavage; group C (highdosage experimental group), 0.6 mL/day curcumin solution at a concentration of 3.2 mg/mL by gavage. General condition of the animals was observed after operation. The mice were killed 3, 7 and 14 days after operation (8 mice per group at a time), the tissue of cystiform was harvested to receive gross, histology and immunohistochemistry observation, as well as RT-PCR and Western blot detection. Results All mice survived till the end of experiment. White cystiform tissue was evident on the back of mice subcutaneously in each group. For diameter of the cyst cavity at each time point, group A was obviously greater than groups B and C, and group C was significantly less than group B. Microscope observation showed that inflammatory response in group A was ber than that of groups B and C, and group C was obviously less than group B at 7 and 14 days. There was a significant difference between groups B and C and group A in terms of MMP-2 and MMP-9 expression at 7 and 14 days after curcumin del ivery (P lt; 0.05), and no significant differences were evident at 3 days (P gt; 0.05). There was no significant difference between group B and group C in MMP-2 expression at 7 days after curcumin del ivery (P gt; 0.05), and significant difference was evident at 14 days (P lt; 0.05). There was significant difference bewteen group B and group C in MMP-9 expression at 7 and 14 days after curcumin del ivery (P lt; 0.05). Nuclear translocation of NF-κB P65 was inhibited remarkably after curcumin del ivery,and there were significant differences among three groups at 7 and 14 days (P lt; 0.05), and no significant differences were evident at 3 days (P gt; 0.05). Conclusion Ultra-high molecular weight polyethylene wear particles can stimulate expression of MMP-2 and MMP-9 in cystiform tissue. Curcumin can restrain expression of MMP-2 and MMP-9 in cystiform tissue of air-pouch animal models, and expression of MMP-2 and MMP-9 may be regulated by the activation of NF-κB.