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EP0478769A4 - Porous metal surface and method of production - Google Patents

Porous metal surface and method of production

Info

Publication number
EP0478769A4
EP0478769A4 EP19910909125 EP91909125A EP0478769A4 EP 0478769 A4 EP0478769 A4 EP 0478769A4 EP 19910909125 EP19910909125 EP 19910909125 EP 91909125 A EP91909125 A EP 91909125A EP 0478769 A4 EP0478769 A4 EP 0478769A4
Authority
EP
European Patent Office
Prior art keywords
workpiece
laser
cavities
laser device
medical implant
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP19910909125
Other languages
English (en)
Other versions
EP0478769A1 (fr
Inventor
Clifford M. Bugle
Alfred L. Donlevy
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dynamet Inc
Original Assignee
Dynamet Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dynamet Inc filed Critical Dynamet Inc
Publication of EP0478769A1 publication Critical patent/EP0478769A1/fr
Publication of EP0478769A4 publication Critical patent/EP0478769A4/en
Withdrawn legal-status Critical Current

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2/30767—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
    • A61F2/30771—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth applied in original prostheses, e.g. holes or grooves
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/062—Shaping the laser beam, e.g. by masks or multi-focusing by direct control of the laser beam
    • B23K26/0626—Energy control of the laser beam
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B23K26/06—Shaping the laser beam, e.g. by masks or multi-focusing
    • B23K26/0665—Shaping the laser beam, e.g. by masks or multi-focusing by beam condensation on the workpiece, e.g. for focusing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/08—Devices involving relative movement between laser beam and workpiece
    • B23K26/0823—Devices involving rotation of the workpiece
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/08—Devices involving relative movement between laser beam and workpiece
    • B23K26/083—Devices involving movement of the workpiece in at least one axial direction
    • B23K26/0853—Devices involving movement of the workpiece in at least in two axial directions, e.g. in a plane
    • B23K26/0861—Devices involving movement of the workpiece in at least in two axial directions, e.g. in a plane in at least in three axial directions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/36—Removing material
    • B23K26/38—Removing material by boring or cutting
    • B23K26/382—Removing material by boring or cutting by boring
    • B23K26/389—Removing material by boring or cutting by boring of fluid openings, e.g. nozzles, jets
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K37/00—Auxiliary devices or processes, not specially adapted for a procedure covered by only one of the other main groups of this subclass
    • B23K37/04—Auxiliary devices or processes, not specially adapted for a procedure covered by only one of the other main groups of this subclass for holding or positioning work
    • B23K37/0461—Welding tables
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
    • A61F2/02—Prostheses implantable into the body
    • A61F2/30—Joints
    • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30535—Special structural features of bone or joint prostheses not otherwise provided for
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
    • A61F2250/00—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
    • A61F2250/0058—Additional features; Implant or prostheses properties not otherwise provided for
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/08—Non-ferrous metals or alloys
    • B23K2103/14—Titanium or alloys thereof

Definitions

  • the present invention relates generally to porous metal surfaces and methods for forming such surfaces, particularly for use in medical prostheses.
  • porous surface on selected areas on a medical prosthesis to permit the bone cement, or ideally the bone itself, to penetrate the voids in the surface in order to establish and maintain a strong mechanical bond with the implant.
  • a frequently employed technique for creating such an active implant surface area involves the selective placement of a porous coating on the implant device.
  • the most commonly used porous coatings are gravity or pressure sintered spherical powders, diffusion bonded metal fibers and plasma sprayed powder coatings. Exemplary of such sintered metal powder coatings are those described in our U.S. Patent Nos. 4,612,160 and 4,854,496.
  • Titanium and titanium alloys have experienced wide usage as medical implant materials, especially for medical prostheses such as orthopedic devices in the form of knee and hip joints. Diffusion bonded metal fiber coatings have been produced from titanium wire in the form of random porous fiber metal coatings. Likewise, in plasma sprayed coatings, it is also known to utilize either commercially pure titanium or titanium alloy powders. The desirability of producing porous surfaces on medical prosthetic devices is well-known as seen, for example, in U.S. Patent No. 3,855,638 to Pilliar, U.S. Patent No. 3,605,123 to Hahn, U.S. Patent No. 4,017,911 to Kafesjian and U.S. Patent No. 3,808,606 to Tronzo.
  • the present invention solves these prior shortcomings by providing an improved porous surface which eliminates the opportunity for surface breakaway and subsequent tissue contamination.
  • the present invention provides a process for forming a porous surface on or in a workpiece such as a medical implant, having closely controlled porosity which may be uniformly dispersed or varied in spacing and in size in pre-selected areas over the implant surface.
  • the process of the present invention further provides a porous surface which is more economical to produce than comparable processes such as the commonly used powd ⁇ r .metallurgy sintering cr diffusion bonding processes of the prior art.
  • the present invention also provides a medical implant device having extremely close dimensional tolerances with closely controlled porous - ⁇ surface areas having pores or cavities of selected size and spacing.
  • the present invention provides a porous surface and process for producing same in which the size of each cavity with respect to its diameter and depth may be closely controlled in either a constant or varying pattern across the workpiece to provide consistent high quality surfaces.
  • the cosmetic appearance of the porous surface is enhanced.
  • the present invention is directed to the formation of porous surfaces, wherein a workpiece of, for example, commercially pure titanium, titanium alloy, or cobalt- chromium alloy has a plurality of cavities formed therein of a predetermined diameter, depth and spacing.
  • the method of the present invention comprises the steps of providing a workpiece, such as a medical implant device, for example; mounting the workpiece in a fixture, preferably having positioning means associated therewith; providing a laser in spaced relation to said mounted workpiece; adjusting the power of the laser to provide a laser beam of a selected value whereby a cavity of pre-selected depth is drilled into the surface of the workpiece; and pulsing the laser at a selected frequency while simultaneously moving one or both of the laser and workpiece relative to one another, whereby a plurality of spaced-apart cavities of a pre-selected size and spacing are formed in the workpiece surface.
  • a workpiece such as a medical implant device
  • the porosity may be produced in specific locations, with a pre ⁇ selected size and density of cavities to provide a surface area of closely controlled dimensions particularly suitable for medical implant devices.
  • a workpiece having a porous ⁇ uil ⁇ c ⁇ produced in accordance vitu tn£ present invention is also suitable for uses other than medical implants, such as, for example, titanium components bonded by epoxy to other structural elements.
  • the porous surface provides an excellent base for obtaining a strong mechanical joint with castable epoxy materials.
  • Figure 1 is an enlarged plan view of a porous surface in accordance with the present invention.
  • Figure 2 is a side cross-sectional view taken along line II-II of Figure 1;
  • Figure 3 is a side elevation view of an acetabular cup having a porous surface formed in accordance with the present invention
  • Figure 4 is a side elevation view of a hip prosthetic device having a pattern of surface porosity produced in accordance with the present invention
  • Figure 4A is an enlarged view of a portion of the porous surface taken from area 4A of Figure 4;
  • Figure 5 is an enlarged plan view of a porous surface in accordance with the present invention.
  • Figure 6 is a cross-sectional side view of the surface taken along line VI-VI of Figure 5;
  • Figure 7 is a schematic perspective view of a laser device and workpiece positioning table and associated controls useful in practicing a method of the present invention;
  • Figure 8 is a photomicrograph of a titanium alloy workpiece showing a porous surface produced in accordance with the present invention at a magnification of 20 power;
  • Figure 8A is a photomicrograph of a cobalt- chromium alloy showing a porous surface produced in accordance with the present invention at ⁇ . magnification of 20 power
  • Figure 9 is a photomicrograph showing a cross- sectional side view of two cavities in a titanium alloy workpiece at a magnification of 50 power;
  • Figure 10 is a photomicrograph showing a cross- sectional view of a cavity formed in a titanium alloy at 100 power magnification
  • Figure 11 is a top side perspective view of a tibial knee tray useful in a knee implant system.
  • Figure 12 is a top side perspective view of a femoral knee component useful in a knee implant system.
  • the present invention utilizing a laser enables the production of medical implant devices of very close dimensional tolerances and without potential contamination since the conventional porous surface layer is eliminated.
  • laser is an acronym for light amplification by stimulated emission of radiation. Further description of lasers may be found in Van Nostrand's Scientific Encyclopedia, Seventh Edition, Douglas M. Considine, Editor.
  • materials that are capable of being utilized as lasers are either of the CO- or YAG type.
  • the YAG laser utilizing a neodymium-doped yttrium aluminum garnet material operating at between about 25 to 50 watts of power.
  • the power level is adjusted according to the size, depth, and repetition rate utilized for drilling into the surface layer of the implant substrate being treated.
  • the workpiece such as a medical implant or other workpiece whose surface is to be modified, is positioned in the near focal point of a suitable laser system.
  • the laser may be pulsed, for example, at between about 8 to about 15 pulses per second at the desired power level to produce a cavity of desired depth and diameter. Either the laser beam is moved to another selected position and pulsed again, or the substrate is moved prior to the next laser pulse.
  • Indexing movement of the workpiece or laser device is either continuous or intermittent.
  • the porous surface formed by the present invention may be produced in specific locations on the workpiece and with a selected density of cavities.
  • the porosity produced is easily distinguished from laser marking such as that utilized to mark metal and plastic items for identification or decorative purposes, as such marking is less than 0.005" deep.
  • the depressions are significantly over 0.005* deep, and preferably on the order of about 0.030" deep.
  • the porous surface is integral with the implant base material so as to avoid the flaking contamination problems present in prior coatings applied by sintering, plasma spraying, or by diffusion bonding techniques.
  • a thin workpiece 2 is depicted in idealized fashion having a flat upper surface 4 and a plurality of pores or cavities 6 drilled therein by means of a laser device such as that schematically shown in Figure 7.
  • a laser device such as that schematically shown in Figure 7.
  • the scale of Figures 1 and 2 is enlarged approximately 10 times actual size so that the details of the cavities 6 can be easily seen.
  • the cavities 6 are formed in the surface 4 of the workpiece 2 in a repetitive manner as shewn in Figure 1.
  • the operating conditions are selected such that the cavities 6 have a controlled depth "a" which is less than the thickness of the workpiece 2 so as to avoid complete penetration thereof.
  • a typical overall thickness of the workpiece 2 may be on the order of about 1/8".
  • the cavity diameter "d" is likewise controlled as well as the cavity spacing "s” such that bone ingrowth and bone cement adherence is enhanced.
  • a flat titanium workpiece of "CP" or commercially pure titanium was prepared having a planar surface 4 as in Figures 1 and 2.
  • the titanium substrate 2 was positioned on a moveable work table spaced from a YAG laser.
  • the alignment of the workpiece 2 was calibrated using a red ruby laser alignment beam produced by the laser machine in conventional fashion.
  • a shielding or inert cover gas of argon was turned on and the YAG laser was activated in a pulsating mode having a frequency of approximately 11 pulses per second.
  • the table with the CP titanium substrate 2 mounted thereon was moved beneath the stationary pulsating laser beam and a series of cavities 6 were formed therein along a first row "A", Figure 1.
  • the table and attached workpiece were moved at a constant rate; the laser, which also was pulsed at a constant frequency, formed cavities 6 in an equally spaced manner. Rather than moving at a constant rate, the table and workpiece can be intermittently moved.
  • the laser was turned off and the table returned to the starting position and indexed one cavity spacing "s" perpendicular to the first row "A” of the newly produced cavities.
  • a second row "B” of cavities was formed. This procedure of row indexing was repeated for rows "C” through “H” until the desired modified area of surface porosity was produced.
  • a typical diameter "d” for the cavities 6 is between about 0.020" and about 0.030", with a preferred depth "a” between about 0.020” and 0.030" and a center-to-center cavity spacing "s" of between about 0.025" and 0.030".
  • a preferred range for the cavity spacing is greater than 1/2 a cavity diameter, but preferably less than 0.125".
  • depth a is about 0.020" and a' is about 0.030".
  • Photomicrographs of actual porous surfaces and individual cavities formed by the invention are depicted in Figures 8, 8A, 9 and 10. It will be readily observed from the photomicrographs that a typical cross-sectional cavity geometry is not completely concentric as indicated in Figures 1, 2, 5 and 6 of the drawings. Rather, the cavities are slightly skewed from the vertical axes in the direction of the travel direction of the positioning table. This slightly skewed configuration is actually beneficial in that it presents a greater opportunity for stronger mechanical bonding between the cement and/or bone structure and the implant than is the case with a smooth, concentrically formed cavity surface. The small melted and frozen protrusions at the top surface of the cavities can also be readily removed for cosmetic purposes through a simple tumbling operation after the laser drilling step is completed.
  • the photomicrographs of Figures 8, 9 and 10 show a plurality of cavities having a diameter of about 0.024", a depth of about 0.025", with a spacing of about 0.030" from cavity center to cavity center.
  • a femoral stem of a hip prosthesis 8 constructed, for example, of a Titanium-6 Aluminum-4 Vanadium ELI alloy is depicted in Figure 4 having a porous surface portion 10 formed in accordance with the present invention.
  • the pore pattern 10, as seen in Figure 4A is triangular in plan view configuration and was applied to selected areas to enhance bone ingrowth on the anterior and posterior surfaces of the mplantable device 0.
  • cavities 12 were formed in surface 10 having a diameter of 0.024" and a depth of 0.025" with a center-to-center cavity spacing of 0.03.0" average.
  • an acetabular hip cup 14 in the shape of a thin- walled hemisphere has its outer surface treated according to the present invention wherein a porous surface 16 is formed around a selected portion thereof.
  • a typical acetabular hip cup 14 includes spaced screw holes 18, 18' formed therein for securement of screws directly to the bone.
  • the cup 14 possesses a thin wall, on the order of about 0.125" thick, which makes laser drilling of the cavities to a controlled depth of about 0.030" particularly desirable.
  • FIG. 11 Examples of other complex surface geometries are shown in Figures 11 and 12.
  • a tibial knee tray 50 having a porous surface 52 formed in accordance with the invention is shown in Figure 11.
  • a femoral knee component 60 having a porous surface 62 formed in accordance with the present invention is depicted in Figure 12.
  • the femoral knee component 60 and the tibial knee tray 50 are useful components in a knee implant system.
  • a substrate 20 of a cobalt-chromium medical implant alloy designated ASTM F-75-87 was treated in accordance with the present invention.
  • Figure 8A depicts a photomicrograph of the cobalt-chromium medical implant alloy at 20 power magnification showing controlled porosity produced with the YAG laser beam.
  • the cavities are typically 0.027" in diameter and 0.021" average depth with a center-to-center spacing of about 0.030".
  • the ASTM type F-75-87 cobalt- chromium alloy is a cast material and it is understood that the wrought cobalt-chromium alloy designated ASTM F-799-87 is also suitable.
  • FIG. 10 A single cavity formed in a Titanium-6 Aluminum-4 Vanadium ELI alloy is depicted in the photomicrograph of Figure 10, at a 100 power magnification. It is observed in Figure 10 that the laser drilling technique of the present invention utilizing a quickly pulsed beam produces a very thin heat affected zone surrounding each cavity. The heat affected zone is shown as a white layer in the photomicrograph, with the balance of the micro structure unaffected by the highly localized melting effected by the pulsed laser beam. Thus, the metallurgical structure and mechanical properties of the adjacent titanium alloy material are substantially unaffected by the laser drilling technique of the present invention.
  • a conventional laser electrical control system 26 for regulating the power and pulse frequency of the laser beam is operably coupled by conduits 28 to a conventional laser beam generator 30.
  • the laser beam generator 30 is mounted on a cross brace 31 carried by a support stand 32 to position the laser beam generator in a spaced location above a workpiece positioning unit 34.
  • the laser beam generator 30 is conventional and may include a YAG, C0_, or like laser source for producing a coherent laser beam 36 useful for causing localized melting in metal or other materials.
  • a conventional lens 37 is mounted on an arm 38 carried by the cross brace 31 for focusing the laser beam 36 on a surface of a workpiece 40, suc as the medical implant acetabular cup 14 or femoral stem 8, as previously described.
  • the -workpiece positioning unit 34 includes a moveable work table 42 carrying a rotatable platen 44 which together are moveable in the three x, y and z axes and rotatable about the y and z axes, as shown in the representation of the x, y and z axes identified by reference numeral 45 in Figure 7. In this manner, the work positioning unit 34 provides five degrees of freedom for positioning the workpiece 40 relative to the laser beam 36 whereby surfaces of any contour can be treated in accordance with the invention.
  • Movement of the workpiece positioning unit 42 is controlled by a conventional numerical controlled or "NC" positioning system control 46 of the type commonly used in the computer controlled machine tool art.
  • the positioning system control 46 is operably coupled to the workpiece positioning unit 42 by way of conduits 48.
  • the workpiece 40 is moved a proper distance and/or at a proper speed relative to the pulse rate of the laser beam 36 controlled by the laser control system 26 to provide proper spacing between the cavities formed in the workpiece 40 by the laser beam 36.
  • a proper focal length is maintained by vertical movement of the workpiece positioning unit effected by the pre-programmed commands supplied by the positioning system control 46 which also controls the horizontal indexing movement of the workpiece positioning unit 34.
  • the workpiece can remain stationary and the laser beam generator 30 can be moved to accomplish similar results.
  • the invention has been described in connection with only one laser beam, it will occur to those skilled in the art that multiple laser beams could be employed simultaneously to form a porous surface according to the invention.

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Plasma & Fusion (AREA)
  • Health & Medical Sciences (AREA)
  • Oral & Maxillofacial Surgery (AREA)
  • Cardiology (AREA)
  • Orthopedic Medicine & Surgery (AREA)
  • Transplantation (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Vascular Medicine (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Prostheses (AREA)

Abstract

Une surface poreuse (2) formée de manière sélective sur une pièce à modeler tel qu'un implant médical (8) en faisant pulser un dispositif à laser d'une manière contrôlée pour produire une multiplicité de petites cavités espacées les unes des autres (6), de profondeur uniforme ou variable. La surface poreuse fournit un élément de prise mécanique au cément osseux ainsi qu'un milieu pour la croissance interne d'os et de tissu.
EP19910909125 1990-04-20 1991-04-18 Porous metal surface and method of production Withdrawn EP0478769A4 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US51155490A 1990-04-20 1990-04-20
US511554 1990-04-20

Publications (2)

Publication Number Publication Date
EP0478769A1 EP0478769A1 (fr) 1992-04-08
EP0478769A4 true EP0478769A4 (en) 1992-07-08

Family

ID=24035396

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19910909125 Withdrawn EP0478769A4 (en) 1990-04-20 1991-04-18 Porous metal surface and method of production

Country Status (3)

Country Link
EP (1) EP0478769A4 (fr)
CA (1) CA2059276A1 (fr)
WO (1) WO1991016012A1 (fr)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT405236B (de) * 1997-07-18 1999-06-25 Implantech Medizintechnik Ges Implantat, insbesondere gelenk-prothesenimplantat
EP0827726A3 (fr) * 1996-09-04 1999-03-03 Implantech Medizintechnik Ges.m.b.H. Implant, en particulier prothèse d'articulation implantable
US7883736B2 (en) 2007-09-06 2011-02-08 Boston Scientific Scimed, Inc. Endoprostheses having porous claddings prepared using metal hydrides
US8696759B2 (en) 2009-04-15 2014-04-15 DePuy Synthes Products, LLC Methods and devices for implants with calcium phosphate
US8475536B2 (en) * 2010-01-29 2013-07-02 DePuy Synthes Products, LLC Methods and devices for implants with improved cement adhesion

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4068052A (en) * 1976-06-23 1978-01-10 Continental Oil Company Reducing PVC polymer buildup in polymerization reactors with dithioxamides and alumina
SE444640B (sv) * 1980-08-28 1986-04-28 Bergentz Sven Erik I djur eller menniska implanterbar kerlprotes samt sett for dess framstellning

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
No relevant documents disclosed *
See also references of WO9116012A1 *

Also Published As

Publication number Publication date
CA2059276A1 (fr) 1991-10-21
EP0478769A1 (fr) 1992-04-08
WO1991016012A1 (fr) 1991-10-31

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