The present invention expands a spinal canal by drilling a cylindrical passage in each pedicle of a vertebra, making a circumferential pedicle cut (osteotomy) through each pedicle from within the passage, separating each pedicle cut by inserting an implant into the passage which distracts the pedicle cut to expand the spinal canal, and securing each pedicle cut, allowing the vertebra to heal with the spinal canal expanded. The implant includes an outer sleeve, an inner bolt, and expandable flanges. The outer sleeve includes an upper portion and a lower portion, with the expandable flanges connected to the lower portion and housed within the upper portion. Rotation of the inner bolt causes the upper and lower portions of the outer sleeve to separate, causing the pedicle cut to widen and the expandable flanges to radially extend into and stabilize the widened pedicle cut to effectuate expansion of the spinal canal.