Abstract: A bone screw comprises a threaded shank including a distal end portion and a proximal end portion, and defining a first threaded section extending from the distal end portion toward the proximal end portion and adapted for anchoring in cancellous bone. A second threaded section extends contiguously from the first threaded section toward the proximal end portion The second threaded section has a finer thread pattern relative to the first threaded section. In one embodiment, the first threaded section includes a first helical threading defining a single lead thread pattern for anchoring in cancellous bone, and the second threaded section includes a second helical threading interleaved with the first threading to define a duel lead thread pattern for engagement in cortical bone. In a further embodiment, the bone screw includes a head portion extending from the threaded shank and configured for coupling to a spinal implant.