**2.2. Implant design**

The device has a mini-ratchet mechanism that allows unidirectional elongation of an expandable rod. It is made out of titanium alloy with an Amorphous Diamond-Like Ceramic coating (**Figure 1**). The expandable rod with polyaxial rings (eye joint) at its' extremities is anchored to the spine with two pedicle screws that are implanted around the apex of the main curve (**Figure 1**). The rod screw connection has a 50° freedom of motion. The rod can expand by 40 mm, depending on the pre-distraction rod length. Rod expansion is incremental and gradual, making the deformity correction safer. The implant has a control pin that can abort the ratchet mechanism and put the device in a neutral mode or in a locked position to create a fusion-like rod (**Figure 1**).

The implant has a CE mark.
