Patent ID: 8920477

Claim:
A method for stabilizing a spondylolisthesis at an articulation of a lumbar vertebra L5 and a sacral vertebra S1, the method comprising: creating an insertion path that extends in a cranial direction from a posterolateral region of a sacral vertebra S1, through the adjoining intervertebral disc, and terminating in an opposite anterolateral region of the lumbar vertebra L5; providing a bone fixation implant comprising an elongated implant structure having a longitudinal axis and a cross-sectional profile transverse to the longitudinal axis that is defined by at least three apices joined together by at least three sides, wherein the elongated implant structure comprises an exterior surface region treated to provide bony in-growth or through-growth along the implant structure; and inserting the bone fixation implant through the insertion path from the posterolateral region of the sacral vertebra S1, through the adjoining intervertebral disc, and terminating in an opposite anterolateral region of the lumbar vertebra L5.