Multi-thread bone screw and method

A bone screw, comprising:

• a threaded shank including a distal end portion and a proximal end portion, said threaded shank defining a first threaded section extending from said distal end portion toward said proximal end portion and adapted for anchoring in cancellous bone, said threaded shank defining a second threaded section extending contiguously from said first threaded section toward said proximal end portion and adapted for engagement in cortical bone, said second threaded section comprising a finer thread pattern relative to said first threaded section, and wherein said threaded shank defines an inner thread root diameter that uniformly increases along a first portion of said first threaded section from a location adjacent said distal end portion to a mid-section of said threaded shank and uniformly increases along a second portion of said second threaded section from said mid-section to a location adjacent said proximal end portion, said first and second threaded sections extend substantially continuously and contiguously along a length of said threaded shank portion;
• and
• wherein said threaded shank includes a first helical threading extending from said distal end portion toward said proximal end portion to define said first threaded section for anchoring in the cancellous bone, said threaded shank including a second helical threading interleaved with and substantially centered between said first helical threading to define said second threaded section for engagement in the cortical bone, each of said first and second helical threadings having a substantially equal thread pitch, and wherein said first threaded section extends along at least about two-thirds of said threaded shank.

A bone screw, comprising:

• a threaded shank including a distal end portion and a proximal end portion, said threaded shank defining a first threaded section extending from said distal end portion toward said proximal end portion and adapted for anchoring in cancellous bone, said threaded shank defining a second threaded section extending contiguously from said first threaded section toward said proximal end portion and adapted for engagement in cortical bone, said second threaded section comprising a finer thread pattern relative to said first threaded section, and wherein said threaded shank defines an inner thread root diameter that uniformly increases along a first portion of said first threaded section from a location adjacent said distal end portion to a mid-section of said threaded shank and uniformly increases along a second portion of said second threaded section from said mid-section to a location adjacent said proximal end portion, said first and second threaded sections extend substantially continuously and contiguously along a length of said threaded shank portion;
• and
• wherein said threaded shank includes a first threading extending from said distal end portion toward said proximal end portion and including a single helical thread pattern defining said first threaded section for anchoring in the cancellous bone, said threaded shank including a second threading cooperating with said first threading to provide a double helical thread pattern defining said second threaded section for engagement in the cortical bone, and wherein said first threading has a first thread pitch, said second threading having a second thread pitch substantially equal to said first thread pitch;
• and
• wherein said first and second threaded sections of said threaded shank define a uniform outer thread diameter from a point adjacent said distal end portion and along said mid-section to said proximal end portion.