The Experts below are selected from a list of 54 Experts worldwide ranked by ideXlab platform

E. Marti - One of the best experts on this subject based on the ideXlab platform.

  • TOTAL HIP ALUMINA/ALUMINA PROSTHESES: PROSPECTIVE MULTI-CENTER STUDY
    2009
    Co-Authors: E. García-cimbrelo, A. Murcia, A. Blanco, E. Marti
    Abstract:

    Introduction and purpose: Different bearing surfaces have been used to prevent osteolysis, such as alumina-alumina. We present here an analysis of the results of a prospective multi-center study of complications related to the use of alumina-alumina bearings. Materials and methods: In 4 hospitals 319 cups with hydroxyapatite stems and alumina-alumina bearing surfaces were implanted with a mean follow-up of 5.6 years (range: 3–8). The mean age of the patients was 52.7 (range: 14–70). Alumina wear was calculated by means of a special program. Results: Revision was performed of 5 cups and 2 stems. In one hip with a horizontal acetabular angle (35°) and a thin alumina Liner (Size 50/32), an acetabular Liner fracture occurred 36 months after surgery. The probability of not undergoing revision due to any cause was 96.9% (CI 95%:94.7–99.1%). None of the patients reported any type of noise. All the non-revised cases showed good results both on clinical and X-ray exam at the end of the follow-up. The difference between the center of the head of the femur and the center of the head of the cup at 6 weeks after surgery was −2.45+0.53 mm, with no further changes seen during the follow-up. Conclusions: These data suggest that the prosthetic alumina-alumina bearing surface has excellent results over 5 years and that alumina fractures are infrequent. No changes were seen in terms of the penetration of the femoral head in any case. Longer follow-ups are necessary to determine if the reduction of wear translates into less osteolysis and loosening.

  • ALUMINA-ON-ALUMINA TOTAL HIP ARTHROPLASTY. A MULTICENTER PROSPECTIVE STUDY
    2009
    Co-Authors: E. García-cimbrelo, Antonio Murcia-mazón, A. Blanco-pozo, E. Marti
    Abstract:

    Introduction. Alternative bearing surfaces to polyethylene have been introduced to avoid the appearance of osteolysis in THR. The aim of this study has been to perform prospective analysis of the data from a multi-center clinical trial for assessing the incidence of early alumina-specific-complications. Material and Methods. We analysed 310 Cerafit cups associated with a Multicone-HA stem using alumina-on-alumina bearings implanted in four institutions from 1999 to 2003, with a mean follow-up of 4.7 years. Patients’ mean age was 52.8+13.4 years. Linear femoral head penetration was analysed using a software package. Results. There were 4 revisions: 2 revisions due to dislocations resulting poor surgical technique (1 cup and 1 stem) and 2 revisions after a trauma (1cup and 1 stem). There was 1 alumina Liner fracture 36 months after implant in a hip with a horizontal acetabular angle (35°) and a thin alumina Liner (Size 50/32). The other cases showed good clinical and radiographic results at the end of follow-up. The radiographic difference between the femoral head and cup centres at 6 weeks postsurgery was 2.48+0.60 mm, without changes in the course of the follow-up. The mean linear femoral head penetration was unreliable (0.00186+0.0032 mm/year) because it was below the mean error for the measurement system. Conclusions. These data demonstrate that Cerafit Alumina-on-Alumina prostheses show excellent results after 5 years. Liner fractures are uncommon. Despite the blurred alumina images, the digitized method, although not totally accurate and used only for a general estimate, allows us to measure the approximate distance between the centre of the cup and the centre of the femoral head. Changes in linear femoral head penetration were not seen in any hip. Continued follow-up should determine if reduction in wear among the alumina-on alumina bearings results in less osteolysis.

Rod Ishmael - One of the best experts on this subject based on the ideXlab platform.

  • Bi-Center Drill Bits and MWD/LWD Tools in a Horizontal Application Prove Effective in Reducing Well Costs and Increasing Liner-Size Capability
    Distributed Computing, 1997
    Co-Authors: Rick Parrish, Coy M Fielder, Rod Ishmael
    Abstract:

    A horizontal drilling program at the Kutubu Project in Papua New Guinea (PNG) called for the use of bi-center drill bit technology to be applied with MWD/LWD tools in a drill-in fluid system. This was the first time that bi-center polycrystalline-diamond-compact (PDC) bits were utilized in a horizontal drilling application. Bit performance while drilling with MWD/LWD tools was enhanced through the use of a Sized-salt biopolymer drill-in fluid system. The fluid system was being enlisted for the first time in PNG. The tool combination was able to drill a larger 91/8-in. hole out of the 95/8-in.-OD casing, as opposed to the 81/2-in, holes in four previous horizontal wells (includes one sidetrack) drilled with conventional PDC bits. The larger hole drilled by the 83/8-by-91/8-in. bi-center bits allowed a 7-in. production Liner to be run, instead of the 51/2-in. Liners run in the previous horizontal wells. The larger Liner permits installation of larger production tubing required to selectively produce the desired 8,000-bopd flowrate, as well as a packer/sliding-sleeve completion system. In addition to the benefit of multizone-completion ability and increased flowrate capability, drilling time in the horizontal section was reduced by 13 days using the bi-center-bit/MWD-LWD combination. This reduction in drilling time alone amounted to more than a $1.56 million savings to the operator. Bi-center drill bit applications can now yield predictable results in demanding directional environments. The ability to log-while-steering in a horizontal lateral while providing an enlarged hole diameter, without need for additional trips in and out of the hole, results in an extremely cost-effective drilling system.

  • bi center drill bits and mwd lwd tools in a horizontal application prove effective in reducing well costs and increasing Liner Size capability
    Distributed Computing, 1997
    Co-Authors: Rick Parrish, Coy M Fielder, Rod Ishmael
    Abstract:

    A horizontal drilling program at the Kutubu Project in Papua New Guinea (PNG) called for the use of bi-center drill bit technology to be applied with MWD/LWD tools in a drill-in fluid system. This was the first time that bi-center polycrystalline-diamond-compact (PDC) bits were utilized in a horizontal drilling application. Bit performance while drilling with MWD/LWD tools was enhanced through the use of a Sized-salt biopolymer drill-in fluid system. The fluid system was being enlisted for the first time in PNG. The tool combination was able to drill a larger 91/8-in. hole out of the 95/8-in.-OD casing, as opposed to the 81/2-in, holes in four previous horizontal wells (includes one sidetrack) drilled with conventional PDC bits. The larger hole drilled by the 83/8-by-91/8-in. bi-center bits allowed a 7-in. production Liner to be run, instead of the 51/2-in. Liners run in the previous horizontal wells. The larger Liner permits installation of larger production tubing required to selectively produce the desired 8,000-bopd flowrate, as well as a packer/sliding-sleeve completion system. In addition to the benefit of multizone-completion ability and increased flowrate capability, drilling time in the horizontal section was reduced by 13 days using the bi-center-bit/MWD-LWD combination. This reduction in drilling time alone amounted to more than a $1.56 million savings to the operator. Bi-center drill bit applications can now yield predictable results in demanding directional environments. The ability to log-while-steering in a horizontal lateral while providing an enlarged hole diameter, without need for additional trips in and out of the hole, results in an extremely cost-effective drilling system.

E. García-cimbrelo - One of the best experts on this subject based on the ideXlab platform.

  • TOTAL HIP ALUMINA/ALUMINA PROSTHESES: PROSPECTIVE MULTI-CENTER STUDY
    2009
    Co-Authors: E. García-cimbrelo, A. Murcia, A. Blanco, E. Marti
    Abstract:

    Introduction and purpose: Different bearing surfaces have been used to prevent osteolysis, such as alumina-alumina. We present here an analysis of the results of a prospective multi-center study of complications related to the use of alumina-alumina bearings. Materials and methods: In 4 hospitals 319 cups with hydroxyapatite stems and alumina-alumina bearing surfaces were implanted with a mean follow-up of 5.6 years (range: 3–8). The mean age of the patients was 52.7 (range: 14–70). Alumina wear was calculated by means of a special program. Results: Revision was performed of 5 cups and 2 stems. In one hip with a horizontal acetabular angle (35°) and a thin alumina Liner (Size 50/32), an acetabular Liner fracture occurred 36 months after surgery. The probability of not undergoing revision due to any cause was 96.9% (CI 95%:94.7–99.1%). None of the patients reported any type of noise. All the non-revised cases showed good results both on clinical and X-ray exam at the end of the follow-up. The difference between the center of the head of the femur and the center of the head of the cup at 6 weeks after surgery was −2.45+0.53 mm, with no further changes seen during the follow-up. Conclusions: These data suggest that the prosthetic alumina-alumina bearing surface has excellent results over 5 years and that alumina fractures are infrequent. No changes were seen in terms of the penetration of the femoral head in any case. Longer follow-ups are necessary to determine if the reduction of wear translates into less osteolysis and loosening.

  • ALUMINA-ON-ALUMINA TOTAL HIP ARTHROPLASTY. A MULTICENTER PROSPECTIVE STUDY
    2009
    Co-Authors: E. García-cimbrelo, Antonio Murcia-mazón, A. Blanco-pozo, E. Marti
    Abstract:

    Introduction. Alternative bearing surfaces to polyethylene have been introduced to avoid the appearance of osteolysis in THR. The aim of this study has been to perform prospective analysis of the data from a multi-center clinical trial for assessing the incidence of early alumina-specific-complications. Material and Methods. We analysed 310 Cerafit cups associated with a Multicone-HA stem using alumina-on-alumina bearings implanted in four institutions from 1999 to 2003, with a mean follow-up of 4.7 years. Patients’ mean age was 52.8+13.4 years. Linear femoral head penetration was analysed using a software package. Results. There were 4 revisions: 2 revisions due to dislocations resulting poor surgical technique (1 cup and 1 stem) and 2 revisions after a trauma (1cup and 1 stem). There was 1 alumina Liner fracture 36 months after implant in a hip with a horizontal acetabular angle (35°) and a thin alumina Liner (Size 50/32). The other cases showed good clinical and radiographic results at the end of follow-up. The radiographic difference between the femoral head and cup centres at 6 weeks postsurgery was 2.48+0.60 mm, without changes in the course of the follow-up. The mean linear femoral head penetration was unreliable (0.00186+0.0032 mm/year) because it was below the mean error for the measurement system. Conclusions. These data demonstrate that Cerafit Alumina-on-Alumina prostheses show excellent results after 5 years. Liner fractures are uncommon. Despite the blurred alumina images, the digitized method, although not totally accurate and used only for a general estimate, allows us to measure the approximate distance between the centre of the cup and the centre of the femoral head. Changes in linear femoral head penetration were not seen in any hip. Continued follow-up should determine if reduction in wear among the alumina-on alumina bearings results in less osteolysis.

Rick Parrish - One of the best experts on this subject based on the ideXlab platform.

  • Bi-Center Drill Bits and MWD/LWD Tools in a Horizontal Application Prove Effective in Reducing Well Costs and Increasing Liner-Size Capability
    Distributed Computing, 1997
    Co-Authors: Rick Parrish, Coy M Fielder, Rod Ishmael
    Abstract:

    A horizontal drilling program at the Kutubu Project in Papua New Guinea (PNG) called for the use of bi-center drill bit technology to be applied with MWD/LWD tools in a drill-in fluid system. This was the first time that bi-center polycrystalline-diamond-compact (PDC) bits were utilized in a horizontal drilling application. Bit performance while drilling with MWD/LWD tools was enhanced through the use of a Sized-salt biopolymer drill-in fluid system. The fluid system was being enlisted for the first time in PNG. The tool combination was able to drill a larger 91/8-in. hole out of the 95/8-in.-OD casing, as opposed to the 81/2-in, holes in four previous horizontal wells (includes one sidetrack) drilled with conventional PDC bits. The larger hole drilled by the 83/8-by-91/8-in. bi-center bits allowed a 7-in. production Liner to be run, instead of the 51/2-in. Liners run in the previous horizontal wells. The larger Liner permits installation of larger production tubing required to selectively produce the desired 8,000-bopd flowrate, as well as a packer/sliding-sleeve completion system. In addition to the benefit of multizone-completion ability and increased flowrate capability, drilling time in the horizontal section was reduced by 13 days using the bi-center-bit/MWD-LWD combination. This reduction in drilling time alone amounted to more than a $1.56 million savings to the operator. Bi-center drill bit applications can now yield predictable results in demanding directional environments. The ability to log-while-steering in a horizontal lateral while providing an enlarged hole diameter, without need for additional trips in and out of the hole, results in an extremely cost-effective drilling system.

  • bi center drill bits and mwd lwd tools in a horizontal application prove effective in reducing well costs and increasing Liner Size capability
    Distributed Computing, 1997
    Co-Authors: Rick Parrish, Coy M Fielder, Rod Ishmael
    Abstract:

    A horizontal drilling program at the Kutubu Project in Papua New Guinea (PNG) called for the use of bi-center drill bit technology to be applied with MWD/LWD tools in a drill-in fluid system. This was the first time that bi-center polycrystalline-diamond-compact (PDC) bits were utilized in a horizontal drilling application. Bit performance while drilling with MWD/LWD tools was enhanced through the use of a Sized-salt biopolymer drill-in fluid system. The fluid system was being enlisted for the first time in PNG. The tool combination was able to drill a larger 91/8-in. hole out of the 95/8-in.-OD casing, as opposed to the 81/2-in, holes in four previous horizontal wells (includes one sidetrack) drilled with conventional PDC bits. The larger hole drilled by the 83/8-by-91/8-in. bi-center bits allowed a 7-in. production Liner to be run, instead of the 51/2-in. Liners run in the previous horizontal wells. The larger Liner permits installation of larger production tubing required to selectively produce the desired 8,000-bopd flowrate, as well as a packer/sliding-sleeve completion system. In addition to the benefit of multizone-completion ability and increased flowrate capability, drilling time in the horizontal section was reduced by 13 days using the bi-center-bit/MWD-LWD combination. This reduction in drilling time alone amounted to more than a $1.56 million savings to the operator. Bi-center drill bit applications can now yield predictable results in demanding directional environments. The ability to log-while-steering in a horizontal lateral while providing an enlarged hole diameter, without need for additional trips in and out of the hole, results in an extremely cost-effective drilling system.

Coy M Fielder - One of the best experts on this subject based on the ideXlab platform.

  • Bi-Center Drill Bits and MWD/LWD Tools in a Horizontal Application Prove Effective in Reducing Well Costs and Increasing Liner-Size Capability
    Distributed Computing, 1997
    Co-Authors: Rick Parrish, Coy M Fielder, Rod Ishmael
    Abstract:

    A horizontal drilling program at the Kutubu Project in Papua New Guinea (PNG) called for the use of bi-center drill bit technology to be applied with MWD/LWD tools in a drill-in fluid system. This was the first time that bi-center polycrystalline-diamond-compact (PDC) bits were utilized in a horizontal drilling application. Bit performance while drilling with MWD/LWD tools was enhanced through the use of a Sized-salt biopolymer drill-in fluid system. The fluid system was being enlisted for the first time in PNG. The tool combination was able to drill a larger 91/8-in. hole out of the 95/8-in.-OD casing, as opposed to the 81/2-in, holes in four previous horizontal wells (includes one sidetrack) drilled with conventional PDC bits. The larger hole drilled by the 83/8-by-91/8-in. bi-center bits allowed a 7-in. production Liner to be run, instead of the 51/2-in. Liners run in the previous horizontal wells. The larger Liner permits installation of larger production tubing required to selectively produce the desired 8,000-bopd flowrate, as well as a packer/sliding-sleeve completion system. In addition to the benefit of multizone-completion ability and increased flowrate capability, drilling time in the horizontal section was reduced by 13 days using the bi-center-bit/MWD-LWD combination. This reduction in drilling time alone amounted to more than a $1.56 million savings to the operator. Bi-center drill bit applications can now yield predictable results in demanding directional environments. The ability to log-while-steering in a horizontal lateral while providing an enlarged hole diameter, without need for additional trips in and out of the hole, results in an extremely cost-effective drilling system.

  • bi center drill bits and mwd lwd tools in a horizontal application prove effective in reducing well costs and increasing Liner Size capability
    Distributed Computing, 1997
    Co-Authors: Rick Parrish, Coy M Fielder, Rod Ishmael
    Abstract:

    A horizontal drilling program at the Kutubu Project in Papua New Guinea (PNG) called for the use of bi-center drill bit technology to be applied with MWD/LWD tools in a drill-in fluid system. This was the first time that bi-center polycrystalline-diamond-compact (PDC) bits were utilized in a horizontal drilling application. Bit performance while drilling with MWD/LWD tools was enhanced through the use of a Sized-salt biopolymer drill-in fluid system. The fluid system was being enlisted for the first time in PNG. The tool combination was able to drill a larger 91/8-in. hole out of the 95/8-in.-OD casing, as opposed to the 81/2-in, holes in four previous horizontal wells (includes one sidetrack) drilled with conventional PDC bits. The larger hole drilled by the 83/8-by-91/8-in. bi-center bits allowed a 7-in. production Liner to be run, instead of the 51/2-in. Liners run in the previous horizontal wells. The larger Liner permits installation of larger production tubing required to selectively produce the desired 8,000-bopd flowrate, as well as a packer/sliding-sleeve completion system. In addition to the benefit of multizone-completion ability and increased flowrate capability, drilling time in the horizontal section was reduced by 13 days using the bi-center-bit/MWD-LWD combination. This reduction in drilling time alone amounted to more than a $1.56 million savings to the operator. Bi-center drill bit applications can now yield predictable results in demanding directional environments. The ability to log-while-steering in a horizontal lateral while providing an enlarged hole diameter, without need for additional trips in and out of the hole, results in an extremely cost-effective drilling system.