Surgical prosthetic implant facilitating vertebral interbody fusion

• US 4,878,915 A
• Filed: 01/04/1989
• Issued: 11/07/1989
• Est. Priority Date: 01/22/1987
• Status: Expired due to Term

• Current Assignee: Depuy Acromed Incorporated (Johnson & Johnson)
• Original Assignee: John W. Brantigan
• Inventors: Brantigan, John W.
• Primary Examiner(s): Cannon, Alan W.
• Application Number:
  US07/293,578
• Time in Patent Office: 307 Days
• Field of Search: 623/17, 623/18, 623/21, 623/22, 128/92 R, 128/924 M, 128/924 J, 128/924 F
• US Class Current: 623/17.11
• CPC Class Codes: A61B 17/16 Bone cutting, breaking or removal means other than saws, e.g. Osteoclasts; Drills or chisels for bones; Trepans arthroscopic bone cutters A61B17/320016; dental implant drills potentially for other surgical use A61C8/0089; bone grinders A61F2/4644, A22C17/06; A61B17/1662 takes precedence over all other subgroups except A61B17/17
• CPC Class Codes: A61B 17/1604 Chisels; Rongeurs; Punches; Stamps
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61B 17/686 Plugs, i.e. elements forming interface between bone hole and implant or fastener, e.g. screw
• CPC Class Codes: A61B 17/7059 Cortical plates A61B17/7007, A61B17/7058 take precedence
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61F 2/30723 Plugs or restrictors for sealing a cement-receiving space tools for inserting plugs A61F2/4614; sealing collars for use during cementing A61B17/8808
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30771 applied in original prostheses, e.g. holes or grooves
• CPC Class Codes: A61F 2/30965 Reinforcing the prosthesis by embedding particles or fibres during moulding or dipping
• CPC Class Codes: A61F 2/42 for wrists or ankles; for hands, e.g. fingers; for feet, e.g. toes
• 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 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• CPC Class Codes: A61F 2/4465 having a circular or kidney shaped cross-section substantially perpendicular to the axis of the spine
• CPC Class Codes: A61F 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• 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 2/4684 : Trial or dummy 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 2002/2839 : Bone plugs or bone graft dowels
• CPC Class Codes: A61F 2002/3008 : radio-opaque, e.g. radio-opaque markers
• CPC Class Codes: A61F 2002/30113 : circular
• CPC Class Codes: A61F 2002/30123 : with two diametrically opposed lobes
• CPC Class Codes: A61F 2002/30153 : rectangular
• CPC Class Codes: A61F 2002/30154 : square
• CPC Class Codes: A61F 2002/30179 : X-shaped
• CPC Class Codes: A61F 2002/30224 : cylindrical
• CPC Class Codes: A61F 2002/30261 : parallelepipedal
• CPC Class Codes: A61F 2002/30263 : cubical
• CPC Class Codes: A61F 2002/3028 : polyhedral different from parallelepipedal and pyramidal
• CPC Class Codes: A61F 2002/30405 : made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30576 : with extending fixation tabs
• CPC Class Codes: A61F 2002/30578 : having apertures, e.g. for receiving fixation screws
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30772 : Apertures or holes, e.g. of circular cross section
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/30797 : internally-threaded
• CPC Class Codes: A61F 2002/308 : oblong
• CPC Class Codes: A61F 2002/30805 : Recesses of comparatively large area with respect to their low depth
• CPC Class Codes: A61F 2002/30836 : knurled
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• 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 2002/449 : comprising multiple spinal implants located in different intervertebral spaces or in different vertebrae
• 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 2002/4629 : connected to the endoprosthesis or implant via a threaded connection
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2230/0006 : circular
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0021 : square
• CPC Class Codes: A61F 2230/0058 : X-shaped
• CPC Class Codes: A61F 2230/0063 : Three-dimensional shapes
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0082 : parallelepipedal
• CPC Class Codes: A61F 2230/0084 : cubical
• CPC Class Codes: A61F 2250/0098 : radio-opaque, e.g. radio-opaque markers
• 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 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: Y10S 606/907 : Composed of particular material or coated

Abstract

Prosthesis plug implants forming transverse struts between adjacent vertebrae have roughened surfaces receiving bone ingrowth to fuse the plugs on prepared surface sites on opposed faces of adjacent vertebrae and have end faces with tool receiving recesses securing the plug on a tool for insertion on the prepared sites of the vertebrae and for removing the tool from the plug without disturbing its position on the sites. These sites are prepared by feeding a drill through a guide fixed to posterior or anterior sides of adjacent vertebrae to form transverse side-by-side channels including cortex bone in the opposed faces of the adjacent vertebrae and terminating the drilling in advance of the opposite sides of the vertebrae. A plurality of the plug implants are each threaded on the end of the tool surrounded by a sleeve and are inserted endwise in exact position on the prepared side-by-side sites. The sleeve is then pushed into a recess in the end of the plug and firmly held while the tool is unthreaded from the plug to prevent disturbing the exact position of the plug on the prepared sites.

Claims

1. A prosthetic plug implant for forming a rigid transverse strut between opposed prepared posterior to anterior transversely extending laterally spaced channels in faces of adjacent vertebrae of a vertebral column to maintain the disc space therebetween which comprises at least a pair of laterally spaced side-by-side rigid inert plugs sized and shaped to fit the prepared channels in the faces of the vertebrae and having roughened surfaces on the periphery thereof, said roughened surfaces having irregularities to interlock with the bone of the prepared channels and recesses for receiving bone to facilitate bone ingrowth, and said plugs each having an end face with tool receiving and mounting means extending internally of the plug to secure each plug endwise on the end of a tool for inserting the plug endwise transversely of the axis of the vertebral column in the prepared channels and to accommodate removal of the tool from the plug after insertion.

4. The implant of claim 1, wherein the plug has a rigid biologically inert body and the roughened surfaces are barbs radiating from the body of the plug and having leading faces sloping toward the tool receiving end of the plug to facilitate insertion and to bite into the bone of the prepared channels of the vertebrae and provide extended areas receiving bone ingrowth.

5. The implant of claim 1, wherein the roughened surfaces are selected from the group consisting of knurled surfaces, pitted surfaces, barbed surfaces, bristle surfaces, and threaded surfaces engaging the prepared channels.

6. The implant of claim 1, wherein the roughened surfaces are barbs radiating from the plug periphery and deformable in the direction of insertion of the plug to facilitate insertion on the prepared sites and biting into the prepared sites upon attempted retraction of the plug.

7. The implant of claim 1, wherein the plug is a solid rod having a diameter sufficiently large to engage the hard cortex bone of the vertebrae and a length sufficient to span the soft cancellous bone of the vertebrae without projecting beyond the cortex bone.

8. The implant of claim 1, wherein the roughened surfaces are on the periphery of a plastics material coating of the plug.

2. In a vertebral column with adjoining vertebrae bodies having spaced opposed faces with a disc space therebetween, each body having peripheral hard cortex bone surrounding soft cancellous bone and said faces having opposed posterior to anterior transverse prepared channels including said cortex bone, the improvement of at least two laterally spaced side-by-side rigid inert prosthetic plugs transversely spanning the disc space in a posterior to anterior direction with opposite faces bottomed on the bone of the prepared channels and providing a rigid transverse strut maintaining the disc space, a roughened surface on each plug, said roughened surface having barbs for biting into the bone and recesses between the barbs for receiving bone ingrowth to fuse the vertebrae bodies together, each plug having an end face with tool receiving means extending internally of the plug for securing the plug endwise on a first tool to facilitate endwise insertion of the plug in the prepared channels, and said end face having a second tool receiving recess to prevent rotation of the plug during removal of the first tool from the means extending internally of the plug.

3. A prosthesis for a vertebral column having transverse posterior to anterior prepared channels on opposed faces of adjoining vertebrae and a disc space between the adjoining vertebrae which comprises posterior to anterior laterally spaced side-by-side rigid inert plugs sized and shaped to form transverse posterior to anterior struts bottomed on the prepared channels of the adjoining vertebrae and maintaining a desired disc space between said adjoining vertebrae, each plug having a roughened surface biting into and interlocking with the bone of said prepared channels and providing irregularities to facilitate bone ingrowth from the vertebrae, and each plug having an end face with tool receiving means extending internally of the plug for removeably mounting the plug endwise on a tool to facilitate endwise insertion of the plug on the prepared channels.

9. The implant of claim 3, including a radial slot in the end face radiating from the internally threaded hole.