A bone screw having a threaded proximal portion, a threaded median portion, and a threaded distal portion. The threaded proximal portion has a proximal thread with a constant diameter and a proximal pitch. The threaded median portion has a median thread with a constant diameter smaller than the diameter of the proximal thread and a median pitch that becomes increasingly smaller from a distal end of the threaded median portion towards a proximal end of the threaded median portion. The threaded distal portion has a distal thread having a constant diameter that is smaller than the diameter of the median thread and a distal pitch that is larger than the median pitch at the distal end of the threaded median portion.