US6436139B1 — Interbody fusion device with anti-rotation featur…

Claim 1

Independent Claim 269 words

A fusion device for introduction in the space between adjacent vertebrae, comprising: an elongated body formed of a biocompatible material having a proximal end, a distal end, a longitudinal axis, and an outer surface defining a constant diameter extending between said proximal and said distal ends; means adapted to engage an insertion tool; a thread pattern having at least one external thread formed on said outer surface, and said at least one external thread includes a thread crest having a height and a width, and said thread pattern defining an advancing rotation direction from said distal end to said proximal end, wherein said thread pattern includes a first thread turn adjacent said proximal end, said first thread turn having a first height, and a second thread turn adjacent said distal end, said second thread turn having a second height, said first height being larger than said second height, and wherein said thread pattern includes a taper between said first thread turn and said second thread turn; a pair of substantially similar thread cut outs on said at least one external thread and located on diametrically opposite side of said elongated body and extending substantially parallel to said longitudinal axis of said body, each of said thread cut outs forming a barb and an undercut, said undercut barb facing away from said advancing rotation direction, wherein said elongated body further includes opposing concave side walls interrupting said thread pattern and extending from substantially said proximal end to said distal end, said opposing concave side walls having a radius of curvature substantially equal to a maximum diameter of said fusion device.

Claim 2

Dependent Claim 269 words

A fusion device for introduction in the space between adjacent vertebrae, comprising: an elongated body formed of a biocompatible material having a proximal end, a distal end, a longitudinal axis, and an outer surface defining a constant diameter extending between said proximal and said distal ends; means adapted to engage an insertion tool; a thread pattern having at least one external thread formed on said outer surface, and said at least one external thread includes a thread crest having a height and a width, and said thread pattern defining an advancing rotation direction from said distal end to said proximal end, wherein said thread pattern includes a first thread turn adjacent said proximal end, said first thread turn having a first height, and a second thread turn adjacent said distal end, said second thread turn having a second height, said first height being larger than said second height, and wherein said thread pattern includes a taper between said first thread turn and said second thread turn; a pair of substantially similar thread cut outs on said at least one external thread and located on diametrically opposite side of said elongated body and extending substantially parallel to said longitudinal axis of said body, each of said thread cut outs forming a barb and an undercut, said undercut barb facing away from said advancing rotation direction, wherein said elongated body further includes opposing concave side walls interrupting said thread pattern and extending from substantially said proximal end to said distal end, said opposing concave side walls having a radius of curvature substantially equal to a maximum diameter of said fusion device.

Claim 3

Dependent Claim 46 words

The fusion device of claim 1 , wherein said thread cut outs intersect said thread pattern at an angular offset along said advancing rotation direction with respect to an axis which dissects said concave side walls, said angular offset ranges from 0° to less than 90°.

Claim 4

Dependent Claim 13 words

The fusion device of claim 1 , further including a hollow interior chamber.

Claim 5

Dependent Claim 16 words

The fusion device of claim 1 , further including upper, lower and lateral bone ingrowth windows.

Claim 6

Dependent Claim 15 words

The fusion device of claim 1 , further including openings cut along said thread cutouts.

Claim 7

Dependent Claim 22 words

The fusion device of claim 1 wherein said thread cut outs are substantially parallel to said outer surface of said elongated body.

Claim 8

Dependent Claim 58 words

The fusion device of claim 1 , further including an interior cavity adapted to receive bone growth-promoting material, and at least one bone ingrowth window disposed through at least one of said pair of thread cut outs of said elongated body thereby allowing communication of said bone growth promoting material placed in said interior cavity with surrounding bones.

Claim 9

Dependent Claim 228 words

A fusion cage for insertion in spinal column comprising: an elongated body having an outer surface extending along a longitudinal axis from a first end to a second end, said outer surface including two opposing concave segments and two opposing convex segments, said opposing concave and convex segments extending between said first end and said second end; an external thread pattern defined on said opposing convex segments having a first thread form adjacent said first end, said first thread form having a first height, and a second thread form adjacent said second end, said second thread form having a second height larger than said first height, wherein said thread pattern includes a taper between said first thread form and said second thread form, and said thread pattern defining an advancing rotation direction from said second end to said first end; and a thread cut out interrupting at least one thread form on said convex segment, and forming a thread overhang and an undercut, said thread overhang faces away from said advancing direction, wherein said external thread pattern defines a first diameter and said thread cut out includes a second diameter substantially less than said first diameter and wherein said thread cut out is formed at an angle of less than 45° with respect to a ray intersecting an intersection between said external thread and said thread cut out.

Claim 10

Dependent Claim 228 words

A fusion cage for insertion in spinal column comprising: an elongated body having an outer surface extending along a longitudinal axis from a first end to a second end, said outer surface including two opposing concave segments and two opposing convex segments, said opposing concave and convex segments extending between said first end and said second end; an external thread pattern defined on said opposing convex segments having a first thread form adjacent said first end, said first thread form having a first height, and a second thread form adjacent said second end, said second thread form having a second height larger than said first height, wherein said thread pattern includes a taper between said first thread form and said second thread form, and said thread pattern defining an advancing rotation direction from said second end to said first end; and a thread cut out interrupting at least one thread form on said convex segment, and forming a thread overhang and an undercut, said thread overhang faces away from said advancing direction, wherein said external thread pattern defines a first diameter and said thread cut out includes a second diameter substantially less than said first diameter and wherein said thread cut out is formed at an angle of less than 45° with respect to a ray intersecting an intersection between said external thread and said thread cut out.

Claim 11

Dependent Claim 13 words

The fusion cage of claim 8 , wherein said angle is substantially 30°.

Claim 12

Dependent Claim 17 words

The fusion cage of claim 8 , wherein said thread cut out has a substantially arcuate configuration.

Claim 13

Dependent Claim 22 words

The fusion cage of claim 10 , wherein said arcuate configuration forms a concave portion on said trailing portion of said thread.

Claim 14

Dependent Claim 24 words

The fusion cage of claim 8 , wherein said thread cut out includes a portion of said thread and a portion of said body.

Claim 15

Dependent Claim 43 words

The fusion cage of claim 8 , wherein said external thread pattern includes multiple thread turns and said thread cut out removes a successively larger portion of said thread turns as the cut out extends from a proximal end to a distal end.

Claim 16

Dependent Claim 18 words

The fusion cage of claim 8 , wherein said second diameter is less than half said first diameter.

Claim 17

Dependent Claim 19 words

The fusion cage of claim 8 , wherein said second diameter is less than 25% of said first diameter.

Claim 18

Dependent Claim 19 words

The fusion cage of claim 8 , wherein said second diameter is less than 10% of said first diameter.

Claim 19

Dependent Claim 26 words

The fusion cage of claim 8 , wherein said thread cut out defines a leading edge, an opposite trailing edge, a thread overhang, and a recess.

Claim 20

Dependent Claim 34 words

The fusion cage of claim 17 , wherein said elongated body includes a longitudinal axis and a ray extending between said longitudinal axis and said thread overhang, said recess being offset from said ray.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2005-08-19	2006-02-18	2006-08-20	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2009-08-19	2010-02-18	2010-08-20	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2013-08-19	2014-02-18	2014-08-20	$7700.00	Window Closed / Lapsed

Interbody fusion device with anti-rotation features

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