Barrel-shaped apparatus for fusing adjacent bone structure

• US 20050159816A1
• Filed: 01/07/2005
• Published: 07/21/2005
• Est. Priority Date: 10/24/2000
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Inventors: Walkenhorst, Jared, Middleton, Lance, Cohen, Herb
• Granted Patent: US 8,870,956 B2
• Time in Patent Office: Days
• US Class Current: 623/17.110
• CPC Class Codes: A61F 2/30771 applied in original prostheses, e.g. holes or grooves
• 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 2002/2817 Bone stimulation by chemical reactions or by osteogenic or biological products for enhancing ossification, e.g. by bone morphogenetic or morphogenic proteins [BMP] or by transforming growth factors [TGF]
• 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 2002/30286 barrel-shaped
• CPC Class Codes: A61F 2002/30593 hollow
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/30787 inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30828 parallel
• CPC Class Codes: A61F 2002/30879 Ribs
• CPC Class Codes: A61F 2002/30892 parallel
• 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 2230/0063 Three-dimensional shapes
• 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 2310/00179 Ceramics or ceramic-like structures

Abstract

A fusion implant apparatus for facilitating fusion of adjacent bone structures includes a threadless implant member which is positioned between adjacent opposed bone structures. The implant member defines a longitudinal axis and first and second longitudinal ends and has an outer wall which is dimensioned to engage the opposed bone structures upon positioning therebetween in supporting relation therewith. The outer wall defines an internal cavity for the reception of bone growth inducing substances and includes a plurality of apertures which extend therethrough in communication with the internal cavity to permit fusion of vertebral bone tissue. The implant member also includes an intermediate portion which defines a cross-sectional dimension transverse to the longitudinal axis which is greater than the respective cross-sectional dimensions of the first and second longitudinal ends of the implant member.

Claims

1. A fusion implant apparatus for facilitating fusion of adjacent bone structures, which comprises

an elongate implant member for positioning between adjacent opposed bone structures, the implant member defining a longitudinal axis extending along its length and first and second longitudinal ends, and having an outer wall dimensioned to engage the opposed bone structures upon positioning therebetween in supporting relation therewith, the outer wall defining an internal cavity for reception of bone growth inducing substances and including a plurality of apertures extending therethrough in communication with the internal cavity to permit fusion of vertebral bone tissue, the implant member having an intermediate portion between the first and second longitudinal ends with a girth relative to the longitudinal axis which is greater than the girths of the first and second longitudinal ends, the intermediate portion having an arcuate lengthwise shape and a rounded cross-section in a plane perpendicular to the longitudinal axis.

2. The fusion implant apparatus according to claim 1 wherein the girth of the implant member increases from each of the first and second ends toward the intermediate portion.

3. The fusion implant apparatus according to claim 2 wherein the girths of the first and second ends are substantially equal.

4. The fusion implant apparatus according to claim 3 wherein the implant member is substantially symmetric about a plane which bisects its length.

5. The fusion implant apparatus according to claim 4 wherein the intermediate portion has a substantially circular cross-section in a plane perpendicular to the longitudinal axis.

6. The fusion implant apparatus according to claim 1 wherein the outer wall of the implant member includes at least one concave wall portion extending along its length.

7. The fusion implant apparatus according to claim 6 wherein the outer wall includes opposed concave wall portions.

8. The fusion implant apparatus according to claim 1 wherein the implant member is dimensioned and configured for insertion between adjacent vertebrae.

9. A fusion implant apparatus for facilitating fusion of adjacent vertebrae, which comprises:

an elongate implant member dimensioned for positioning between adjacent vertebrae to support the adjacent vertebrae in spaced relation, the implant member defining a longitudinal axis extending along its length and first and second longitudinal ends, and having an outer wall constructed to engage the adjacent vertebrae upon positioning therebetween, the outer wall defining an internal cavity for reception of bone growth inducing substances, the implant member having an intermediate portion between the first and second longitudinal ends with a girth relative to the longitudinal axis greater than the girths of the first and second longitudinal ends of the implant member, the intermediate portion having an arcuate lengthwise shape and a rounded cross-section in a plane perpendicular to the longitudinal axis, the outer wall having a plurality of apertures extending therethrough in communication with the internal cavity to permit fusion of vertebral bone tissue.

10. The fusion implant apparatus according to claim 9 wherein the girth of the implant member increases from each of the first and second ends toward the intermediate portion.

11. The fusion implant apparatus according to claim 10 wherein the implant member is substantially symmetric about a plane which bisects its length, whereby the girth of the implant member decreases toward each of the first and second longitudinal ends.

12. The fusion implant apparatus according to claim 9 wherein the outer wall of the implant member includes at least one concave wall surface portion extending along its length.

13. A method for fusing adjacent vertebrae, comprising the steps of:

providing an elongate

implant member defining a longitudinal axis extending along its length and first and second longitudinal ends, the implant member having an intermediate portion between the first and second longitudinal ends with a girth relative to the longitudinal axis which is greater than the girths of the first and second longitudinal ends of the implant member, the intermediate portion having an arcuate lengthwise shape and a rounded cross-section in a plane perpendicular to the longitudinal axis;

accessing the intervertebral space defined between adjacent vertebrae;

advancing the implant member within the intervertebral space such that the first and second longitudinal ends are adjacent respective anterior and posterior sections of the adjacent vertebrae; and

permitting bone growth into contacting surfaces of the implant member to facilitate fusion of the adjacent vertebrae.

14. The method of claim 13 wherein the implant member includes an exterior wall defining an internal cavity and having apertures extending therethrough and further including the step of providing a bone growth inducing substance within the internal cavity and permitting bony tissue of the adjacent vertebrae to grow through the apertures to communicate with the bone growth inducing substance.