The Experts below are selected from a list of 237 Experts worldwide ranked by ideXlab platform
Ben Luan - One of the best experts on this subject based on the ideXlab platform.
-
Fabrication of Ti/polymer biocomposites for load-Bearing Implant applications
Journal of Materials Processing Technology, 2020Co-Authors: J F Wang, Ben LuanAbstract:This paper presents a two-step method for the fabrication of Ti/polymer biocomposites. In the first step, a porous titanium substrate was produced by powder compaction and sintering. The porosity and pore structure of the substrate were controlled by varying the sintering process parameters. In the second step, high-density polyethylene (HDPE) or polyurethane (PU) was impregnated into the porous titanium substrate to form Ti/polymer biocomposites with the assistance of a hydraulic pressure. Ti/polymer composites with the polymer volume fraction varying from 21% to 37% have been successfully fabricated. Suitable impregnation parameters such as temperature, pressure and holding time for HDPE and PU were determined.Peer reviewed: YesNRC publication: Ye
-
fabrication of ti polymer biocomposites for load Bearing Implant applications
Journal of Materials Processing Technology, 2008Co-Authors: J F Wang, Ben LuanAbstract:Abstract This paper presents a two-step method for the fabrication of Ti/polymer biocomposites. In the first step, a porous titanium substrate was produced by powder compaction and sintering. The porosity and pore structure of the substrate were controlled by varying the sintering process parameters. In the second step, high-density polyethylene (HDPE) or polyurethane (PU) was impregnated into the porous titanium substrate to form Ti/polymer biocomposites with the assistance of a hydraulic pressure. Ti/polymer composites with the polymer volume fraction varying from 21% to 37% have been successfully fabricated. Suitable impregnation parameters such as temperature, pressure and holding time for HDPE and PU were determined.
Angel L. Díez-vicente - One of the best experts on this subject based on the ideXlab platform.
-
Nano-TiO2 Reinforced PEEK/PEI Blends as Biomaterials for Load-Bearing Implant Applications
ACS Applied Materials & Interfaces, 2015Co-Authors: Ana M. Díez-pascual, Angel L. Díez-vicenteAbstract:Biocompatible ternary nanocomposites based on poly(ether ether ketone) (PEEK)/poly(ether imide) (PEI) blends reinforced with bioactive titanium dioxide (TiO2) nanoparticles were fabricated via ultrasonication followed by melt-blending. The developed biomaterials were characterized using FT-IR, SEM, XRD, DSC, TGA, and DMA. Further, their water-absorption, tensile, tribological, dielectric, and antibacterial properties were evaluated. PEI acts as a coupling agent, since it can interact both with PEEK via π–π stacking and polar interactions as well as with the nanoparticles through hydrogen bonding, as corroborated by the FT-IR spectra, which resulted in a homogeneous titania dispersion within the biopolymer blend without applying any particle surface treatment or polymer functionalization. A change from promotion to retardation in the crystallization rate of the matrix was found with increasing TiO2 concentration, while its crystalline structure remained unaltered. The nanoparticles stiffened, strengthened,...
-
Nano-TiO2 reinforced PEEK/PEI blends as biomaterials for load-Bearing Implant applications
ACS Applied Materials and Interfaces, 2015Co-Authors: Ana M. Díez-pascual, Angel L. Díez-vicenteAbstract:Biocompatible ternary nanocomposites based on poly(ether ether ketone) (PEEK)/poly(ether imide) (PEI) blends reinforced with bioactive titanium dioxide (TiO2) nanoparticles were fabricated via ultrasonication followed by melt-blending. The developed biomaterials were characterized using FT-IR, SEM, XRD, DSC, TGA, and DMA. Further, their water-absorption, tensile, tribological, dielectric, and antibacterial properties were evaluated. PEI acts as a coupling agent, since it can interact both with PEEK via π-π stacking and polar interactions as well as with the nanoparticles through hydrogen bonding, as corroborated by the FT-IR spectra, which resulted in a homogeneous titania dispersion within the biopolymer blend without applying any particle surface treatment or polymer functionalization. A change from promotion to retardation in the crystallization rate of the matrix was found with increasing TiO2 concentration, while its crystalline structure remained unaltered. The nanoparticles stiffened, strengthened, and toughened the matrix simultaneously, and the optimal properties were achieved at 4.0 wt % TiO2. More interesting, the tensile properties were retained after steam sterilization in an autoclave or exposure to a simulated body fluid (SBF). The nanocomposites also displayed reduced water absorption though higher thermal stability, storage modulus, glass transition temperature, dielectric constant, and dielectric loss compared to the control blend. Further, remarkable enhancements in the tribological properties under both SBF and dry environments were attained. The nanoparticles conferred antibacterial action versus Gram-positive and Gram-negative bacteria in the presence and the absence of UV light, and the highest inhibition was attained at 4.0 wt % nanoparticle concentration. These nanocomposites are expected to be used in long-term load-Bearing Implant applications. © 2015 American Chemical Society.
Constantine A. Demetracopoulos - One of the best experts on this subject based on the ideXlab platform.
-
Sagittal Tibiotalar Alignment May Not Affect Functional Outcomes in Fixed-Bearing Total Ankle Replacement: A Retrospective Cohort Study
HSS Journal ®, 2019Co-Authors: Natalie M. Nielsen, Guilherme H. Saito, Austin E. Sanders, Scott J. Ellis, Carolyn M. Sofka, Constantine A. DemetracopoulosAbstract:Background In total ankle replacement (TAR), correct positioning of the Implant is crucial. Malposition of the components may increase contact pressures and diminish prosthesis survival. The effect of sagittal tibiotalar alignment on functional outcomes after fixed-Bearing TAR remains unclear, however, and no studies have compared fixed-Bearing Implants with respect to the anteroposterior (AP) position of the talar component. Questions/Purpose The purposes of this study were (1) to evaluate the effect of sagittal tibiotalar alignment on functional outcomes in fixed-Bearing TAR and (2) to compare post-operative sagittal tibiotalar alignment in two types of fixed-Bearing Implants. Methods In a retrospective analysis of 71 primary TARs performed at a single center, we studied the INBONE™ II Total Ankle System and the Salto Talaris^® Ankle. Radiographic measurements of the tibial axis–talus (T-T) ratio and the AP offset ratio were performed before and after surgery, respectively, and we evaluated Foot and Ankle Outcome Scores (FAOSs) and the 12-item Short Form Health Survey (SF-12) mental component summary (MCS) and physical component summary (PCS) scales pre-operatively and at 2 years after surgery. The Pearson correlation and independent-samples t test were used to evaluate differences in FAOSs, SF-12 MCS scores, and SF-12 PCS scores regarding post-operative sagittal alignment. Results Post-operative sagittal tibiotalar alignment was neutral in 39 ankles and anterior in 32 ankles. We observed no significant between-group differences in clinical outcome scores. Patients with a Salto Talaris Ankle prosthesis had a greater AP offset ratio (0.12) than patients with an INBONE II Implant (0.05). However, the greater translation did not correlate with outcome scores. Conclusion At the 2-year follow-up, no correlation between the post-operative AP offset ratio and functional outcome scores was observed between the two fixed-Bearing-Implant groups. Further studies with longer follow-up are needed to determine whether the difference in sagittal alignment has an effect on functional outcomes in the long term.
-
Sagittal Tibiotalar Alignment May Not Affect Functional Outcomes in Fixed-Bearing Total Ankle Replacement: A Retrospective Cohort Study
HSS Journal, 2019Co-Authors: Natalie Nielsen, Guilherme H. Saito, Austin E. Sanders, Scott J. Ellis, Carolyn M. Sofka, Constantine A. DemetracopoulosAbstract:In total ankle replacement (TAR), correct positioning of the Implant is crucial. Malposition of the components may increase contact pressures and diminish prosthesis survival. The effect of sagittal tibiotalar alignment on functional outcomes after fixed-Bearing TAR remains unclear, however, and no studies have compared fixed-Bearing Implants with respect to the anteroposterior (AP) position of the talar component. The purposes of this study were (1) to evaluate the effect of sagittal tibiotalar alignment on functional outcomes in fixed-Bearing TAR and (2) to compare post-operative sagittal tibiotalar alignment in two types of fixed-Bearing Implants. In a retrospective analysis of 71 primary TARs performed at a single center, we studied the INBONE™ II Total Ankle System and the Salto Talaris® Ankle. Radiographic measurements of the tibial axis–talus (T-T) ratio and the AP offset ratio were performed before and after surgery, respectively, and we evaluated Foot and Ankle Outcome Scores (FAOSs) and the 12-item Short Form Health Survey (SF-12) mental component summary (MCS) and physical component summary (PCS) scales pre-operatively and at 2 years after surgery. The Pearson correlation and independent-samples t test were used to evaluate differences in FAOSs, SF-12 MCS scores, and SF-12 PCS scores regarding post-operative sagittal alignment. Post-operative sagittal tibiotalar alignment was neutral in 39 ankles and anterior in 32 ankles. We observed no significant between-group differences in clinical outcome scores. Patients with a Salto Talaris Ankle prosthesis had a greater AP offset ratio (0.12) than patients with an INBONE II Implant (0.05). However, the greater translation did not correlate with outcome scores. At the 2-year follow-up, no correlation between the post-operative AP offset ratio and functional outcome scores was observed between the two fixed-Bearing-Implant groups. Further studies with longer follow-up are needed to determine whether the difference in sagittal alignment has an effect on functional outcomes in the long term.
Lluis Guirao Cano - One of the best experts on this subject based on the ideXlab platform.
-
improvement in bone mineral density after a distal weight Bearing Implant in a series of 13 cases
Jpo Journal of Prosthetics and Orthotics, 2020Co-Authors: Lluis Guirao Cano, Beatriz Samitier Pastor, Dolores Maldonado Garrido, Manuel Rodriguezpinero Duran, Jose Exposito Tirado, Isabel Peraitacosta, Maria MoralessuarezvarelaAbstract:ABSTRACTIntroductionThe amputation of lower limbs and the subsequent use of a prosthesis require the adoption of new biomechanical patterns of load and gait by the patient, which may favor the onset of local or generalized bone mineral density loss. Osseo-anchored Implants that allow distal weight b
-
effect of a distal weight Bearing Implant on visual analog scale scores in 23 transfemoral amputees
International Journal of Rehabilitation Research, 2018Co-Authors: Lluis Guirao Cano, Beatriz Samitier Pastor, Dolores Maldonado Garrido, Manuel Rodriguezpinero Duran, Jose Exposito Tirado, Isabel Peraitacosta, Maria MoralessuarezvarelaAbstract:: The objective of this interrupted time series clinical trial was to evaluate the effect of a distal weight-Bearing Implant on well-being in patients with transfemoral amputations using the visual analog scale (VAS). A total of 29 patients from five hospitals with previous transfemoral amputations were surgically Implanted with an osseoanchored Implant with a distal spacer that allows a direct load on the residuum over the distal surface of the socket. Patients were followed for a 14-month period and assessed presurgically and postsurgically using the VAS. The Wilcoxon test was used to evaluate the differences between variables. VAS mean scores improved significantly after intervention. Significant and clinically meaningful improvements in the VAS score suggest overall improvement in well-being for patients after receiving a distal weight-Bearing Implant.
-
improvement of walking abilities in femoral amputees with a distal weight Bearing Implant
Annals of Physical and Rehabilitation Medicine, 2016Co-Authors: Lluis Guirao CanoAbstract:Objective Following a transfemoral (TF) amputation, the ability to walk with a prosthesis is the main objective of rehabilitation. The achieved speed of walking is considered a determining factor in the amputee's perception of quality of life. This experimental before-after study evaluates the walking abilities and improvement of important parameters such as gait, walking speed, pain and hours of prosthesis use in transfemoral amputees after placing a novel femoral Implant that permits distal weight Bearing of the residuum within a socket, adapted for distal load Bearing. Material and methods Thirty TF amputees with an amputee history of more than 12 months received an all-inside femoral Implant, comprised of a femoral stem and a polyethylene spacer that allows distal load of the residuum within an adapted socket. The post-intervention follow-up period was 14 months. The applied rehabilitation schedule was our standard one, and no hardware changes were allowed during the follow-up period of 14 months, except for the adapted socket. Functionality was evaluated using the standard 2-minute walk test (2MWT) and the physiological cost index (PCI). Results To date 19 patients (8 trauma, 8 vascular and 3 tumour patients) have finished the follow-up period. Prior to the Implant placement the mean 2MWT covered distance was 103.16 m (SD = 33.03), and at 14 months was 124.95 m (SD = 39.22), ( P = 0.00); an increase of 21.1%. The initial mean Visual Analogue Pain (VAS) score was 2.26 (SD = 2.76) and at 14 months 0.42 (SD = 0.77), ( P P Discussion/Conclusion The results of the present study show significant improvements in walking speed, pain reduction, hours of prosthesis use and general health status at 14 months after having received a femoral distal load Implant in patients of different ethiology.
J F Wang - One of the best experts on this subject based on the ideXlab platform.
-
Fabrication of Ti/polymer biocomposites for load-Bearing Implant applications
Journal of Materials Processing Technology, 2020Co-Authors: J F Wang, Ben LuanAbstract:This paper presents a two-step method for the fabrication of Ti/polymer biocomposites. In the first step, a porous titanium substrate was produced by powder compaction and sintering. The porosity and pore structure of the substrate were controlled by varying the sintering process parameters. In the second step, high-density polyethylene (HDPE) or polyurethane (PU) was impregnated into the porous titanium substrate to form Ti/polymer biocomposites with the assistance of a hydraulic pressure. Ti/polymer composites with the polymer volume fraction varying from 21% to 37% have been successfully fabricated. Suitable impregnation parameters such as temperature, pressure and holding time for HDPE and PU were determined.Peer reviewed: YesNRC publication: Ye
-
fabrication of ti polymer biocomposites for load Bearing Implant applications
Journal of Materials Processing Technology, 2008Co-Authors: J F Wang, Ben LuanAbstract:Abstract This paper presents a two-step method for the fabrication of Ti/polymer biocomposites. In the first step, a porous titanium substrate was produced by powder compaction and sintering. The porosity and pore structure of the substrate were controlled by varying the sintering process parameters. In the second step, high-density polyethylene (HDPE) or polyurethane (PU) was impregnated into the porous titanium substrate to form Ti/polymer biocomposites with the assistance of a hydraulic pressure. Ti/polymer composites with the polymer volume fraction varying from 21% to 37% have been successfully fabricated. Suitable impregnation parameters such as temperature, pressure and holding time for HDPE and PU were determined.