Expandable intervertebral fusion implant and applicator

• US 6,183,517 B1
• Filed: 12/16/1998
• Issued: 02/06/2001
• Est. Priority Date: 12/16/1998
• Status: Expired due to Term

• Current Assignee: Zimmer Spine, Inc. (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Loubert Suddaby
• Inventors: Suddaby, Loubert
• Primary Examiner(s): Millin, V.
• Assistant Examiner(s): STEWART, ALVIN J
• Application Number:
  US09/212,288
• Time in Patent Office: 783 Days
• Field of Search: 623/17, 623/17.11, 623/17.12, 623/17.13, 623/17.15, 623/17.16
• US Class Current: 623/17.16
• CPC Class Codes: A61F 2/30724 Spacers for centering an implant in a bone cavity, e.g. in a cement-receiving cavity
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• 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 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30125 elliptical or oval
• CPC Class Codes: A61F 2002/30197 Omega-shaped
• CPC Class Codes: A61F 2002/30228 Cylinders of elliptical or oval basis
• CPC Class Codes: A61F 2002/30401 with additional means for preventing or locking said sliding
• CPC Class Codes: A61F 2002/30487 Circumferential cooperating grooves and beads on cooperating lateral surfaces of a mainly longitudinal connection
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/3052 unrestrained in only one direction, e.g. moving unidirectionally
• CPC Class Codes: A61F 2002/30522 releasable, e.g. using a releasable ratchet
• CPC Class Codes: A61F 2002/3055 for adjusting length
• CPC Class Codes: A61F 2002/30556 for adjusting thickness
• CPC Class Codes: A61F 2002/30574 with an integral complete or partial collar or flange
• 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 2002/30777 : Oblong apertures
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30789 : perpendicular 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 2002/448 : comprising multiple adjacent spinal implants within the same intervertebral space or within the same vertebra, e.g. comprising two adjacent spinal implants
• CPC Class Codes: A61F 2002/4627 : with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2002/4628 : with linear motion along or rotating motion about an axis transverse to the instrument axis or to the implantation direction, e.g. clamping
• CPC Class Codes: A61F 2002/4635 : using minimally invasive surgery
• CPC Class Codes: A61F 2002/4641 : for disconnecting
• CPC Class Codes: A61F 2002/4689 : acoustic
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/0008 : elliptical or oval
• CPC Class Codes: A61F 2230/0045 : Omega-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0009 : for adjusting thickness
• CPC Class Codes: A61F 2250/0063 : Nested prosthetic parts
• CPC Class Codes: A61F 2310/00017 : Iron- or Fe-based alloys, e.g. stainless steel
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00173 : Graphite
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures

Abstract

An expandable intervertebral fusion implant includes a pair of semi-cylindrical shells having mating surfaces which resist shifting when the parts are assembled. The cylinder thus formed is placed on a special installation tool, which is first used to place the cylinder in the intervertebral space. Thereafter, the tool is actuated to spread the shells, and a spacer of appropriate size and taper is slid over the tool shaft, and in between the shells to maintain their spacing after the tool is removed. Having spacers of different height and taper allow the surgeon to adapt the implant to various situations.

Claims

1. An expandable intervertebral fusion implant comprising

a pair of shells having mating surfaces so that when joined, the shells form substantially a tube,

said mating surfaces having complementary profiles to prevent lateral and longitudinal shifting of the shells with respect to one another once they are assembled,

a spacer for placement between the shells, once they have been positioned in an intervertebral space, so as to give the spacer a predetermined total height appropriate for the intervertebral space, said spacer having mating surfaces complementary to those of the shells,

wherein the spacer comprises a pair of parallel walls interconnected by an cylindrical center portion having a longitudinal through hole.

2. The invention of claim 1, wherein the longitudinal hole has an internal diameter substantially the same as that of said tube.

3. The invention of claim 1, wherein each of said shells has one end wall, said end walls having mating edges provided with complementary nesting profiles to prevent longitudinal shifting of said shells.