Patent ID: 8128671
Filing Date: 2012-03-06
Classification: A61B

Abstract:
1. A bone screw, comprising: A head portion; and a threaded shank portion having a longitudinal axis and including a single thread lead defining a thread root diameter, said single thread lead including a first helical threading extending along a first length of said threaded shank portion distal said head portion, and a second helical threading extending from a location proximately adjacent said first helical threading and along a second length of said threaded shank portion proximate said head portion, said first and second helical threadings of said single thread lead defining a substantially constant thread pitch along said first and second lengths of said threaded shank portion, said first helical threading defining a first substantially constant volume between adjacent thread turns along said first length, said second helical threading defining a second substantially constant volume between adjacent thread turns along said second length, wherein said second volume is less than said first volume, wherein said adjacent thread turns of said first helical threading define opposing thread flanks that are separated by a first distance at said thread root diameter, said adjacent thread turns of said second helical threading defining opposing thread flanks that are separated by a second distance at said thread root diameter, and wherein said second distance is less than said first distance.