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US4868237A Expired / Lapsed US ⏱️ 0.0 years remaining

Mechanically disruptible bone cement

Assignee: Merck Patent GmbH
•
Filing: 1985-10-24
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Granted: 1989-09-19
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Expires: 2005-10-24
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Abstract

Abstract The invention relates to a bone cement based on physiologically tolerated polymers, the incorporation of acoustic perturbation elements having a sound resistance differing from that of the polymer making it possible, in the case of a necessary re-operation, to disrupt the bone cement by the application of acoustic waves to such an extent that it can easily be removed from the implant location.

Inventors

  • 👤 Gunter Hoff
  • 👤 Jochen Ohnsorge

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 10:30
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/88; A61B17/8802; A61L; A61L24/00; A61L24/001; A61L24/0047; A61L24/0073; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/46; A61F2002/4631; A61L2430/00; A61L2430/02; A61N; A61N7/00

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 54 words
A method of mechanically disintegrating a matrix of a sold cured polymer containing acoustic perturbation elements having an acoustic resistance differing from that of the polymer by a factor of at least 1.5, said method comprising selectively exciting the perturbation elements by means of sufficiently high intensity acoustic waves, thereby destroying the polymer matrix.
Claim 2
Independent Claim 54 words
A method of mechanically disintegrating a matrix of a sold cured polymer containing acoustic perturbation elements having an acoustic resistance differing from that of the polymer by a factor of at least 1.5, said method comprising selectively exciting the perturbation elements by means of sufficiently high intensity acoustic waves, thereby destroying the polymer matrix.
Claim 3
Dependent Claim 38 words
A method of claim 1, wherein said polymer is at least one of a polyacrylate and polymethacrylate, and wherein the perturbation elements are present in the polymer in a quantity of about 0.5 to about 20% by volume.
Claim 4
Dependent Claim 35 words
A method of claim 2, wherein the acoustic perturbation elements have a thickness of about 0.01 to about 2 mm, and comprise TiAL 5 Fe 2 .5, CoCrMo, Ta or Al 2 O 3 .
Claim 5
Independent Claim 92 words
A method of facilitating the mechanical destruction of a cured solid polymer based on physiologically tolerated polymers comprising at least one of a polyacrylate and a polymethacrylate prepared from a prepolymer and a monomer, which method comprises incorporating into the polymer while it is in the pasty condition, perturbation elements having an acoustic resistance differing from that of the polymer, said perturbation elements comprising TiAl 5 Fe 2 .5, whereby resultant cured composition can later be disintegrated by selective excitation of said perturbation elements by applying acoustic waves of sufficiently high intensity.
Claim 6
Independent Claim 92 words
A method of facilitating the mechanical destruction of a cured solid polymer based on physiologically tolerated polymers comprising at least one of a polyacrylate and a polymethacrylate prepared from a prepolymer and a monomer, which method comprises incorporating into the polymer while it is in the pasty condition, perturbation elements having an acoustic resistance differing from that of the polymer, said perturbation elements comprising TiAl 5 Fe 2 .5, whereby resultant cured composition can later be disintegrated by selective excitation of said perturbation elements by applying acoustic waves of sufficiently high intensity.
Claim 7
Dependent Claim 26 words
A method of claim 4, wherein the acoustic perturbation elements are present in the polymer in a quantity of about 0.5 to about 20% by volume.
Claim 8
Dependent Claim 21 words
A method according to claim 4, wherein the acoustic perturbation elements have a thickness of about 0.01 to about 2 mm.
Claim 9
Dependent Claim 21 words
A method according to claim 5, wherein the acoustic perturbation elements have a thickness of about 0.01 to about 2 mm.
Claim 10
Dependent Claim 21 words
A method according to claim 7, wherein TiAl 5 Fe 2 .5 is in the form of an ellipsoid of revolution.
Claim 11
Independent Claim 112 words
A method for mechanically disintegrating a solid cured polymer, the latter comprising at least one member from the group consisting of a polyacrylate and a polymethacrylate, said polymer having been prepared from a prepolymer and a monomer and having incorporated therein, while the polymer is in the pasty condition, acoustic perturbation elements having an acoustic resistance different from that of the solid polymer by at least 1.5, said method comprising destroying the matrix of the cured polymer by selective excitation of the perturbation elements by means of acoustic waves which are either extracorporeally generated, focused shock waves, or ultrasonic waves having a frequency tuned to the characteristic frequency of the perturbation elements.
Claim 12
Independent Claim 112 words
A method for mechanically disintegrating a solid cured polymer, the latter comprising at least one member from the group consisting of a polyacrylate and a polymethacrylate, said polymer having been prepared from a prepolymer and a monomer and having incorporated therein, while the polymer is in the pasty condition, acoustic perturbation elements having an acoustic resistance different from that of the solid polymer by at least 1.5, said method comprising destroying the matrix of the cured polymer by selective excitation of the perturbation elements by means of acoustic waves which are either extracorporeally generated, focused shock waves, or ultrasonic waves having a frequency tuned to the characteristic frequency of the perturbation elements.
Claim 13
Dependent Claim 17 words
A method of claim 9 which comprises employing extracorporeally generated, focused shock waves as the acoustic waves.
Claim 14
Dependent Claim 25 words
A method claim 9, which comprises employing as the acoustic waves ultrasonic waves having a frequency tuned to the characteristic frequency of the perturbation elements.
Claim 15
Dependent Claim 20 words
A method of claim 9, wherein the acoustic perturbation elements have a thickness of about 0.01 to about 2 mm.
Claim 16
Dependent Claim 22 words
A method claim 9, wherein the acoustic perturbation elements are present in a quantity of about 0.5 to about 20% by volume.
Claim 17
Dependent Claim 27 words
A method of claim 13, wherein the acoustic perturbation elements have a thickness of about 0.01 to about 2 mm, and comprise TiAl 5 Fe 2 .5.
Claim 18
Dependent Claim 16 words
A method of claim 9 wherein the acoustic perturbation elements comprise TiAl 5 Fe 2 .5.
Claim 19
Dependent Claim 20 words
A method of claim 15, wherein TiAl 5 Fe 2 .5 is in the form of an ellipsoid of revolution.

References Cited (Backward Citations)

US4341691A Cited
US4456711A Cited
US4490497A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-09-18 1993-03-20 1993-09-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-09-18 1997-03-20 1997-09-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-09-18 2001-03-20 2001-09-19 $7700.00 Window Closed / Lapsed

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