Patent ID: 6436139
Filing Date: 2002-08-20
Classification: A61F

Abstract:
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.