			Home About us Contact

Orthopaedic Implants (orthopaedic + implant)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Progress and Challenge for Magnesium Alloys as Biomaterials,

ADVANCED ENGINEERING MATERIALS, Issue 8 2008
R. Zeng
Abstract Magnesium alloys are very biocompatiable and show promise for use in orthopaedic implant. Significant progress of research on bioabsorbable magnesium stents and orthopaedic bones has been achieved in recent years. The issues on degradation, hydrogen evolution, and corrosion fatigue and erosion corrosion of magnesium alloys and various influencing factors in simulated body fluid (SBF) are discussed. The research progress on magnesium and its alloys as biomaterials and miscellaneous approaches to enhancement in corrosion resistance is reviewed. Finally the challenges and strategy for their application as orthopaedic biomaterials are also proposed. [source]

Prevention and control of biofilm-based medical-device-related infections

FEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 3 2010
Iolanda Francolini
Abstract Biofilms play a pivotal role in healthcare-associated infections, especially those related to the implant of medical devices, such as intravascular catheters, urinary catheters and orthopaedic implants. This paper reviews the most successful approaches for the control and prevention of these infections as well as promising perspectives for the development of novel devices refractory to microbial adhesion, colonization and biofilm formation. [source]

Enhancing the mechanical integrity of the implant,bone interface with BoneWelding® technology: Determination of quasi-static interfacial strength and fatigue resistance

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2006
Stephen J. Ferguson
Abstract The BoneWelding® technology is an innovative bonding method, which offers new alternatives in the treatment of fractures and other degenerative disorders of the musculoskeletal system. The BoneWelding process employs ultrasonic energy to liquefy a polymeric interface between orthopaedic implants and the host bone. Polymer penetrates the pores of the surrounding bone and, following a rapid solidification, forms a strong and uniform bond between implant and bone. Biomechanical testing was performed to determine the quasi-static push-out strength and fatigue performance of 3.5-mm-diameter polymeric dowels bonded to a bone surrogate material (Sawbones solid and cellular polyurethane foam) using the BoneWelding process. Fatigue tests were conducted over 100,000 cycles of 20,100 N loading. Mechanical test results were compared with those obtained with a comparably-sized, commercial metallic fracture fixation screw. Tests in surrogate bone material of varying density demonstrated significantly superior mechanical performance of the bonded dowels in comparison to conventional bone screws (p < 0.01), with holding strengths approaching 700 N. Even in extremely porous host material, the performance of the bonded dowels was equivalent to that of the bone screws. For both cellular and solid bone analog materials, failure always occurred within the bone analog material surrounding and distant to the implant; the infiltrated interface was stronger than the surrounding bone analog material. No significant decrease in interfacial strength was observed following conditioning in a physiological saline solution for a period of 1 month prior to testing. Ultrasonically inserted implants migrated, on average, less than 20 ,m over, and interfacial stiffness remained constant the full duration of fatigue testing. With further refinement, the BoneWelding technology may offer a quicker, simpler, and more effective method for achieving strong fixation and primary stability for fracture fixation or other orthopaedic and dental implant applications. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006 [source]

PGE2 and IL-6 production by fibroblasts in response to titanium wear debris particles is mediated through a Cox-2 dependent pathway

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2004
Susan V. Bukata
Aseptic loosening of orthopaedic implants is precipitated by wear debris-induced osteolysis. Central to this process are the pro-inflammatory mediators that are produced in response to wear by the fibroblastic cells, which comprise the majority of periprosthetic membranes. Since this pro-inflammatory cascade is mediated by a plethora of factors with redundant functions, it is imperative to establish a hierarchy. Two well-known fibroblast derived pro-inflammatory factors that stimulate wear debris-induced osteoclastic resorption are prostaglandin E2 (PGE2) and IL-6. However, their relationship to each other in this process is poorly defined. Here we show immunohistochemistry of retrieval membranes indicating that COX-2 is the principal cyclooxygenase responsible for PGE2 production in fibroblasts around failed implants. We also performed in vitro experiments with fibroblasts derived from wild-type (WT), COX-1 (,/,) and COX-2 (,/,) mice, which demonstrated that COX-2 is required for Ti wear debris-induced PGE2 production. Interestingly, COX-2 was also required for IL-6 production in these assays, which could be rescued by the addition of exogenous PGE2 (10,6 M). Pharmacology studies that utilized the COX-1 selective inhibitor SC 560, the COX-2 selective inhibitor celecoxib, and the nonselective COX inhibitor indomethacin confirmed these results. Taken together, these results indicate that selective inhibition of prostaglandin signaling could favorably impact aseptic loosening beyond its direct effects on PGE2 synthesis, in that it inhibits downstream pro-inflammatory/pro-osteoclastic cytokine production. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source]