Joint arthroplasty had revolutionized the outcome of orthopaedic surgery. Extensive and collaborative work of many innovator surgeons had led to the development of durable bearing surfaces, yet no single material is c...Joint arthroplasty had revolutionized the outcome of orthopaedic surgery. Extensive and collaborative work of many innovator surgeons had led to the development of durable bearing surfaces, yet no single material is considered absolutely perfect. Generation of wear debris from any part of the prosthesis is unavoidable. Implant loosening secondary to osteolysis is the most common mode of failure of arthroplasty. Osteolysis is the resultant of complex contribution of the generated wear debris and the mechanical instability of the prosthetic components. Roughly speaking, all orthopedic biomaterials may induce a universal biologic hostresponse to generated wear débris with little specific characteristics for each material; but some debris has been shown to be more cytotoxic than others. Prosthetic wear debris induces an extensive biological cascade of adverse cellular responses, where macrophages are the main cellular type involved in this hostile inflammatory process. Macrophages cause osteolysis indirectly by releasing numerous chemotactic inflammatory mediators, and directly by resorbing bone with their membrane microstructures. The bio-reactivity of wear particles depends on two major elements: particle characteristics(size, concentration and composition) and host characteristics. While any particle type may enhance hostile cellular reaction, cytological examination demonstrated that more than 70% of the debris burden is constituted of polyethylene particles. Comprehensive understanding of the intricate process of osteolysis is of utmost importance for future development of therapeutic modalities that may delay or prevent the disease progression.展开更多
背景:随着全髋关节置换及翻修患者的不断增加,股骨假体周围骨折的发生率及复杂性随之增加。目的:回顾有关股骨假体周围骨折的研究文献,探讨其危险因素、预防措施、Vancouver分型和治疗方案。方法:以电子检索方式对CNKI数据库、FMJS数据...背景:随着全髋关节置换及翻修患者的不断增加,股骨假体周围骨折的发生率及复杂性随之增加。目的:回顾有关股骨假体周围骨折的研究文献,探讨其危险因素、预防措施、Vancouver分型和治疗方案。方法:以电子检索方式对CNKI数据库、FMJS数据库及PubMed数据库1994年9月至2012年6月收录的有关全髋关节置换后股骨假体周围骨折的研究文献进行分析,检索词为"全髋关节置换,股骨假体周围骨折"和"total hip arthroplasty,periprosthetic femoral fractures",排除报道时间较早的研究或重复研究。结果与结论:随着全髋关节置换人数的增加,置换后股骨假体周围骨折发生率正在增加。目前公认的危险因素包括年龄、性别、创伤、固定方式、假体松动、翻修、骨溶解、置换前疾病、骨质疏松、假体类型和置换技术等。熟悉及理解股骨假体周围骨折的危险因素对其预防及治疗至关重要。Vancouver分型涉及股骨假体周围骨折位置及稳定性、假体松动情况、股骨近端骨量等,是临床上常用的分型方法。临床治疗应根据骨折类型、是否有假体松及骨缺损等采用不同的方法。展开更多
Total joint replacement is a highly successful surgical procedure for treatment of patients with disabling arthritis and joint dysfunction. However, over time, with high levels of activity and usage of the joint, impl...Total joint replacement is a highly successful surgical procedure for treatment of patients with disabling arthritis and joint dysfunction. However, over time, with high levels of activity and usage of the joint, implant wear particles are generated from the articulating surfaces. These wear particles can lead to activation of an inflammatory reaction, and subsequent bone resorption around the implant （periprosthetic osteolysis）. Cells of the monocyte/macrophage lineage orchestrate this chronic inflammatory response, which is dominated by a pro-inflammatory （M 1） macrophage phenotype rather than an anti-inflammatory pro-tissue healing （M2） macrophage phenotype. While it has been shown that interleukin-4 （IL-4） selectively polarizes macrophages towards an M2 anti-inflammatory phenotype which promotes bone healing, rather than inflammation, little is known about the time course in which this occurs or conditions in which repolarization through I L-4 is most effective. The goal of this work was to study the time course of murine macrophage polarization and cytokine release in response to challenge with combinations of polymethyl methacrylate （PMMA） particles, lipopolysaccharide （LPS） and IL-4 in vitro. Treatment of particle-challenged monocyte/macrophages with IL-4 led to an initial suppression of pro-inflammatory cytokines and inducible nitric oxide synthase （iNOS） production and subsequent polarization into an M2 anti-inflammatory phenotype. This result was optimized when IL-4 was delivered before PMMA particle challenge, to an M 1 phenotype rather than to uncommitted （MO） macrophages. The effects of this polarization were sustained over a 5-day time course. Polarization of M1 macrophages into an M2 phenotype may be a strategy to mitigate wear particle associated periprosthetic osteolysis.展开更多
There is convincing evidence that particles produced by the wear of joint prostheses are causal in the periprosthetic loss of bone,or osteolysis,which,if it progresses,leads to the phenomenon of aseptic loosening.It i...There is convincing evidence that particles produced by the wear of joint prostheses are causal in the periprosthetic loss of bone,or osteolysis,which,if it progresses,leads to the phenomenon of aseptic loosening.It is important to fully understand the biology of this bone loss because it threatens prosthesis survival,and loosened implants can result in peri-prosthetic fracture,which is disastrous for the patient and presents a difficult surgical scenario.The focus of this review is the bioactivity of polyethylene(PE)particles,since there is evidence that these are major players in the development and progression of osteolysis around prostheses which use PE as the bearing surface.The review describes the biological consequences of interaction of PE particles with macrophages,osteoclasts and cells of the osteoblast lineage,including osteocytes.It explores the possible cellular mechanisms of action of PE and seeks to use the findings to date to propose potential nonsurgical treatments for osteolysis.In particular,a nonsurgical approach is likely to be applicable to implants containing newer,highly cross-linked PEs(HXLPEs),for which osteolysis seems to occur with much reduced PE wear compared with conventional PEs.The caveat here is that we know little as yet about the bioactivity of HXLPE particles and addressing this constitutes our next challenge.展开更多
文摘Joint arthroplasty had revolutionized the outcome of orthopaedic surgery. Extensive and collaborative work of many innovator surgeons had led to the development of durable bearing surfaces, yet no single material is considered absolutely perfect. Generation of wear debris from any part of the prosthesis is unavoidable. Implant loosening secondary to osteolysis is the most common mode of failure of arthroplasty. Osteolysis is the resultant of complex contribution of the generated wear debris and the mechanical instability of the prosthetic components. Roughly speaking, all orthopedic biomaterials may induce a universal biologic hostresponse to generated wear débris with little specific characteristics for each material; but some debris has been shown to be more cytotoxic than others. Prosthetic wear debris induces an extensive biological cascade of adverse cellular responses, where macrophages are the main cellular type involved in this hostile inflammatory process. Macrophages cause osteolysis indirectly by releasing numerous chemotactic inflammatory mediators, and directly by resorbing bone with their membrane microstructures. The bio-reactivity of wear particles depends on two major elements: particle characteristics(size, concentration and composition) and host characteristics. While any particle type may enhance hostile cellular reaction, cytological examination demonstrated that more than 70% of the debris burden is constituted of polyethylene particles. Comprehensive understanding of the intricate process of osteolysis is of utmost importance for future development of therapeutic modalities that may delay or prevent the disease progression.
文摘背景:随着全髋关节置换及翻修患者的不断增加,股骨假体周围骨折的发生率及复杂性随之增加。目的:回顾有关股骨假体周围骨折的研究文献,探讨其危险因素、预防措施、Vancouver分型和治疗方案。方法:以电子检索方式对CNKI数据库、FMJS数据库及PubMed数据库1994年9月至2012年6月收录的有关全髋关节置换后股骨假体周围骨折的研究文献进行分析,检索词为"全髋关节置换,股骨假体周围骨折"和"total hip arthroplasty,periprosthetic femoral fractures",排除报道时间较早的研究或重复研究。结果与结论:随着全髋关节置换人数的增加,置换后股骨假体周围骨折发生率正在增加。目前公认的危险因素包括年龄、性别、创伤、固定方式、假体松动、翻修、骨溶解、置换前疾病、骨质疏松、假体类型和置换技术等。熟悉及理解股骨假体周围骨折的危险因素对其预防及治疗至关重要。Vancouver分型涉及股骨假体周围骨折位置及稳定性、假体松动情况、股骨近端骨量等,是临床上常用的分型方法。临床治疗应根据骨折类型、是否有假体松及骨缺损等采用不同的方法。
文摘Total joint replacement is a highly successful surgical procedure for treatment of patients with disabling arthritis and joint dysfunction. However, over time, with high levels of activity and usage of the joint, implant wear particles are generated from the articulating surfaces. These wear particles can lead to activation of an inflammatory reaction, and subsequent bone resorption around the implant （periprosthetic osteolysis）. Cells of the monocyte/macrophage lineage orchestrate this chronic inflammatory response, which is dominated by a pro-inflammatory （M 1） macrophage phenotype rather than an anti-inflammatory pro-tissue healing （M2） macrophage phenotype. While it has been shown that interleukin-4 （IL-4） selectively polarizes macrophages towards an M2 anti-inflammatory phenotype which promotes bone healing, rather than inflammation, little is known about the time course in which this occurs or conditions in which repolarization through I L-4 is most effective. The goal of this work was to study the time course of murine macrophage polarization and cytokine release in response to challenge with combinations of polymethyl methacrylate （PMMA） particles, lipopolysaccharide （LPS） and IL-4 in vitro. Treatment of particle-challenged monocyte/macrophages with IL-4 led to an initial suppression of pro-inflammatory cytokines and inducible nitric oxide synthase （iNOS） production and subsequent polarization into an M2 anti-inflammatory phenotype. This result was optimized when IL-4 was delivered before PMMA particle challenge, to an M 1 phenotype rather than to uncommitted （MO） macrophages. The effects of this polarization were sustained over a 5-day time course. Polarization of M1 macrophages into an M2 phenotype may be a strategy to mitigate wear particle associated periprosthetic osteolysis.
文摘There is convincing evidence that particles produced by the wear of joint prostheses are causal in the periprosthetic loss of bone,or osteolysis,which,if it progresses,leads to the phenomenon of aseptic loosening.It is important to fully understand the biology of this bone loss because it threatens prosthesis survival,and loosened implants can result in peri-prosthetic fracture,which is disastrous for the patient and presents a difficult surgical scenario.The focus of this review is the bioactivity of polyethylene(PE)particles,since there is evidence that these are major players in the development and progression of osteolysis around prostheses which use PE as the bearing surface.The review describes the biological consequences of interaction of PE particles with macrophages,osteoclasts and cells of the osteoblast lineage,including osteocytes.It explores the possible cellular mechanisms of action of PE and seeks to use the findings to date to propose potential nonsurgical treatments for osteolysis.In particular,a nonsurgical approach is likely to be applicable to implants containing newer,highly cross-linked PEs(HXLPEs),for which osteolysis seems to occur with much reduced PE wear compared with conventional PEs.The caveat here is that we know little as yet about the bioactivity of HXLPE particles and addressing this constitutes our next challenge.
