Intervertebral fusion device

• US 5,702,391 A
• Filed: 05/16/1995
• Issued: 12/30/1997
• Est. Priority Date: 05/16/1995
• Status: Expired due to Fees

• Current Assignee: Chih-I Lin
• Original Assignee: Chih-I Lin
• Inventors: Lin, Chih-I
• Primary Examiner(s): Buiz, Michael
• Assistant Examiner(s): Shai, Daphna
• Application Number:
  US08/442,095
• Time in Patent Office: 959 Days
• Field of Search: 606/62, 606/64, 606/65, 606/66, 606/67, 606/68
• US Class Current: 623/17.11
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/30143 hexagonal
• CPC Class Codes: A61F 2002/30235 tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30242 spherical
• CPC Class Codes: A61F 2002/30354 Cylindrically-shaped protrusion and recess, e.g. cylinder of circular basis
• CPC Class Codes: A61F 2002/30364 Rotation about the common longitudinal axis
• CPC Class Codes: A61F 2002/3037 Translation along the common longitudinal axis, e.g. piston
• CPC Class Codes: A61F 2002/30372 with additional means for limiting said translation
• CPC Class Codes: A61F 2002/30405 made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30545 for adjusting a diameter
• CPC Class Codes: A61F 2002/30579 with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30599 stackable
• CPC Class Codes: A61F 2002/30774 internally-threaded
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/30787 inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30892 : parallel
• CPC Class Codes: A61F 2002/30894 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30975 : made of two halves
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2230/0017 : Angular shapes
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0071 : spherical
• CPC Class Codes: A61F 2250/001 : for adjusting a diameter
• CPC Class Codes: A61F 2250/0063 : Nested prosthetic parts

Abstract

An intervertebral fusion device comprises a hollow tubular body, a plurality of stretching elements, an adjustment element, and an urging element. The tubular body is provided peripherally with a plurality of receiving holes in which the stretching elements are disposed movably. The adjustment element is disposed in the hollow interior of the tubular body such that inner ends of the stretching elements are urged by the adjustment element. The urging element is disposed in the hollow interior of the tubular body such that the adjustment element is urged at the top thereof by the bottom of the urging element, and that the adjustment element can be actuated by a rotational motion of the urging element so as to cause the stretching elements to jut out of the receiving holes for bringing about an increase in diameter of the tubular body.

Claims

1. An intervertebral fusion device comprising:

a cylindrical body of a hollow construction and having at a top thereof an opening and further having axially a hollow interior, said cylindrical body provided peripherally with a plurality of through holes communicating the outside of said cylindrical body with said hollow interior of said cylindrical body;

a plurality of stretching elements disposed respectively and movably in said through holes of said cylindrical body such that said stretching elements can be caused to jut out of said through holes, said stretching elements provided respectively with a holding means capable of preventing said stretching elements from becoming disengaged from the cylindrical body;

an adjustment element disposed in said hollow interior of said cylindrical body such that inner ends of said stretching elements are urged by said adjustment element wherein said adjustment element comprises a plurality of separate and discrete members in contact with each other; and

an urging element inserted into said hollow interior of said cylindrical body via said opening located at the top of said cylindrical body such that said adjustment element can be actuated by a rotational motion of said urging element so as to force said stretching elements to extend out of said through holes of said cylindrical body to bring about an increase in diameter of said cylindrical body;

wherein one of said hollow cylindrical body and said adjustment element is provided with a retaining means engageable securely with said holding means of said stretching elements for preventing said stretching elements from becoming disengaged from said cylindrical body via said through holes.

2. The intervertebral fusion device as defined in claim 1, wherein said adjustment element comprises a plurality of spherical bodies making contact with one another.

3. The intervertebral fusion device as defined in claim 1, wherein said opening located at the top of said cylindrical body is a threaded hole;

and wherein said urging element is a fastening screw engaged with said threaded hole.

4. The intervertebral fusion device as defined in claim 1, wherein said adjustment element comprises a plurality of oblong bodies making contact with each other.