A growing rod for mounting between attachment mechanisms that are secured to anatomical structures of a patient having scoliosis. The growing rod includes a base rod having an attachment end, an extendable rod that is translatable relative to the base rod along a longitudinal axis and a housing enclosing at least a portion of the extendable rod therein. A magnet is rotatably mounted within the housing and is enclosed by a top magnet cover and a bottom magnet cover. The magnet includes a first pole and a second pole. A gear reduction mechanism is associated with the magnet and the extendable rod. The gear reduction mechanism reduces an output rotation to the extendable rod relative to an input rotation from the magnet.