Orthopaedic fixation devices, systems and methods

A ratchet fastener, comprising:

• a base including a fastening portion including threads and a ratchet recess including teeth,
• the ratchet recess including an interior-facing sidewall from which the teeth extend radially inward toward a center of the ratchet recess;
• and
• a ratchet wheel disposed in the ratchet recess in mating arrangement with the teeth, the ratchet fastener configured to receive a tether, the ratchet wheel rotatable relative to the ratchet portion of the base for tightening the tether,
• wherein the ratchet recess includes a boss projecting from a central portion of the ratchet recess, the boss receivable in the ratchet wheel when the ratchet wheel is disposed in the ratchet recess in mating arrangement with the teeth,
• wherein the boss includes a protrusion proximal to a top edge of the boss extending radially outward from a center of the boss, wherein the central aperture includes a ledge extending substantially circumferentially around the central aperture and extending radially inward toward a center of the central aperture, wherein a cut-out in the ledge is configured to allow the protrusion to pass through the central aperture when the cut-out and the protrusion are aligned, and wherein the protrusion extends over the ledge when the ratchet wheel is disposed in the ratchet recess and the cut-out and the protrusion are misaligned.