Hip prosthesis structure adapted for easy fitting to the patient coxo-femural articulation

• US 4,957,510 A
• Filed: 07/26/1988
• Issued: 09/18/1990
• Est. Priority Date: 08/03/1987
• Status: Expired due to Term

• Current Assignee: Wright Medical Italy Srl (Stryker Corporation)
• Original Assignee: Patrizio Cremascoli
• Inventors: Cremascoli, Patrizio
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Iantorno, Stephanie L.
• Application Number:
  US07/224,454
• Time in Patent Office: 784 Days
• Field of Search: 623/23
• US Class Current: 623/22.46
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/3609 Femoral heads or necks; Connections of endoprosthetic heads or necks to endoprosthetic femoral shafts A61F2/3601 takes precedence
• CPC Class Codes: A61F 2/3662 Femoral shafts
• CPC Class Codes: A61F 2/367 Proximal or metaphyseal parts of shafts trochanteric devices connected to said proximal parts A61F2/30739
• CPC Class Codes: A61F 2002/30331 made by longitudinally pushing a protrusion into a complementarily-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2002/30332 Conically- or frustoconically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30339 Double cones, i.e. connecting element having two conical connections, one at each of its opposite ends
• CPC Class Codes: A61F 2002/30354 Cylindrically-shaped protrusion and recess, e.g. cylinder of circular basis
• CPC Class Codes: A61F 2002/30355 Cylinder of elliptical or oval basis
• CPC Class Codes: A61F 2002/3054 about a connection axis or implantation axis for selecting any one of a plurality of radial orientations between two modular parts, e.g. Morse taper connections, at discrete positions, angular positions or continuous positions
• CPC Class Codes: A61F 2002/3055 for adjusting length
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30795 Blind bores, e.g. of circular cross-section
• CPC Class Codes: A61F 2002/30797 internally-threaded
• CPC Class Codes: A61F 2002/308 oblong
• CPC Class Codes: A61F 2002/30827 Plurality of grooves
• CPC Class Codes: A61F 2002/30828 parallel
• CPC Class Codes: A61F 2002/3625 Necks
• CPC Class Codes: A61F 2002/3631 with an integral complete or partial peripheral collar or bearing shoulder at its base
• CPC Class Codes: A61F 2002/3652 : Connections of necks to shafts
• CPC Class Codes: A61F 2002/3686 : bent
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit

Abstract

This prosthesis essentially comprises a given size stem at the top portion thereto there is provided an oval cross-section seat for firmly coupling one oval end of a coupling bar, the other frustum of cone shaped end of which bears a spherical head to be coupled to a hip acetabulum, the coupling bar having a variable length and a longitudinal axis of any given angle of inclination.

Claims

1. A hip prosthesis comprising an elongated oval cross-section stem, said stem having a first set curvature, a plurality of longitudinal extending slots formed on said stem, said stem including a first pointed end portion and an opposite enlarged second end portion, said enlarged portion having a second set curvature different from said first set curvature of said stem, a plurality of spaced bone gripping grooves formed on said enlarged end portion, an oval cross-section seat formed in said enlarged portion and a coupling element for coupling said stem to a prosthesis head, said coupling element including a middle body and two coupling element end portions integral with and on opposite ends of said middle body, one of said end portions having an oval cross-section for engaging in said seat and the other of said end portions having a frustum of cone shape, said coupling element being so designed that, as said oval cross-section end of said coupling element is engaged in said seat, said middle body and said other end portion of said coupling element provide an extension having a curvature substantially corresponding to said second set curvature of said enlarged end portion of said stem.