Focused Ion Beam Fabrication

Contains reports on five research projects.DARPA/Naval Electronic Systems Command (Contract MDA-903-85-C-0215)Charles Stark Draper Laboratory (Contract DL-H-261827)U.S. Navy - Office of Naval Research (Contract N00014-84-K-0073)Nippon Telephone and TelegraphHitachi Central Research Laborator

Focused Ion Beam Fabrication

Contains reports on four sections of one research project.Microsystems Technology LaboratoriesDefense Advanced Research Projects Agency/Naval Electronics Systems Command (Contract MDA 903-85-C-0215)U.S. Air Force (through Lincoln Laboratory)Defense Advanced Research Projects Agency (through Lincoln Laboratory)Charles Stark Draper Laboratory, Inc. (Contract DL-H-261827)Hitachi Central Research LaboratoryNippon Telegraph & TelephoneU.S. Army Research Office (Contract DAALO3-87-K-0126

Focused Ion Beam Fabrication

Contains reports on three research projects.Joint Services Electronics Program (Contract DAAG29-83-K-0003)Charles Stark Draper Laboratory (Contract DL-H-225270)International Business Machines, Inc. (Contract 3260

Focused Ion Beam Fabrication

Contains reports on eight research projects.DARPA/Naval Electronics Systems Command (Contract MDA 903-85-C-0215)DARPA/U.S. Army Research Office (Contract DAAL03-88-K-0108)U.S. Army Research Office (Contract DAAL03-87-K-0126)Charles Stark Draper LaboratoryInternational Business Machines Corporation - Research Division, General Technologies DivisionU.S. Air ForceDARP

Surface pretreatment for prolonged survival of cemented tibial prosthesis components: full- vs. surface-cementation technique

BACKGROUND: One of few persisting problems of cemented total knee arthroplasty (TKA) is aseptic loosening of tibial component due to degradation of the interface between bone cement and metallic tibial shaft component, particularly for surface cemented tibial components. Surface cementation technique has important clinical meaning in case of revision and for avoidance of stress shielding. Degradation of the interface between bone cement and bone may be a secondary effect due to excessive crack formation in bone cement starting at the opposite metallic surface. METHODS: This study was done to prove crack formation in the bone cement near the metallic surface when this is not coated. We propose a newly developed coating process by PVD layering with SiO(x )to avoid that crack formation in the bone cement. A biomechanical model for vibration fatigue test was done to simulate the physiological and biomechanical conditions of the human knee joint and to prove excessive crack formation. RESULTS: It was found that coated tibial components showed a highly significant reduction of cement cracking near the interface metal/bone cement (p < 0.01) and a significant reduction of gap formation in the interface metal-to-bone cement (p < 0.05). CONCLUSION: Coating dramatically reduces hydrolytic- and stress-related crack formation at the prosthesis interface metal/bone cement. This leads to a more homogenous load transfer into the cement mantle which should reduce the frequency of loosening in the interfaces metal/bone cement/bone. With surface coating of the tibial component it should become possible that surface cemented TKAs reveal similar loosening rates as TKAs both surface and stem cemented. This would be an important clinical advantage since it is believed that surface cementing reduces metaphyseal bone loss in case of revision and stress shielding for better bone health

Focused Ion Beam Fabrication

Contains reports on ten research projects.U.S. Army Research Office Contract DAAL03-88-K-0108Hughes Research Laboratories FellowshipSEMATECHCharles S. Draper Laboratory Contract DL-H-261827U.S. Army Research Office Contract DAAL03-87-K-0126IBM General Technologies DivisionIBM Research Divisio

Focused Ion Beam Microfabrication

Contains an introduction, reports on x research projects and a list of publications.Defense Advanced Research Projects Agency/U.S. Army Research Office Grant DAAL-03-92-G-0217National Science Foundation Grant ECS 89-21728Defense Advanced Research Projects Agency/U.S. Army Research Office (ASSERT Program) Grant DAAL03-92-G-0305Semiconductor Research CorporationNational Science Foundation Grant DMR 92-02633U.S. Army Research Office Grant DAAL03-90-G-0223U.S. Navy - Naval Research Laboratory/Micrion Contract M0877

Focused Ion Beam Microfabrication

Contains an introduction, reports on seven research projects and a list of publications.Defense Advanced Research Projects Agency/U.S. Army Research Office Contract DAAL03-88-K-0108National Science Foundation Grant ECS 89-21728U.S. Army Research Office Contract DAAL03-87-K-0126U.S. Navy - Naval Research Laboratory/Micrion Agreement M08774SEMATEC

Focused Ion Beam Fabrication

Contains reports on thirteen research projects and a list of publications.Defense Advanced Research Projects Agency/U.S. Army Research Office Contract DAAL03-88-K-0108National Science Foundation Grant ECS 89-21728MIT Lincoln Laboratory Innovative Research ProgramSEMATECH Contract 90-MC-503Micrion Contract M08774U.S. Army Research Office Contract DAAL03-87-K-0126IBM Corporatio