Non-invasive adjustable distraction system

A spinal distraction system comprising:

• a distraction rod having a first end configured for affixation to a subject's spine at a first location and a second end containing a recess having a threaded portion disposed therein;
• an adjustable portion configured for affixation to a subject's spine at a second location remote from the first location and comprising a housing coaxially containing at least a portion of a magnetic assembly affixed at one end thereof to a lead screw by an interface comprising a locking pin passing transversely through the lead screw and the magnetic assembly, the lead screw operatively coupled to the threaded portion of the distraction rod;
• and
• a recess disposed in an interior portion of the housing, the recess having at least one O-ring therein dimensioned to form a fluid tight seal between the housing and the distraction rod;
• wherein upon a rotation of the lead screw and the magnetic assembly about a longitudinal axis, the lead screw is configured to communicate with the threaded portion of the distraction rod to move the distraction rod relative to the adjustable portion and change an axial length of the spinal distraction system, with the interface between the magnetic assembly and the lead screw configured to allow the lead screw to pivot relative to the magnetic assembly, allowing the lead screw to align with the threaded portion and prevent jamming of the lead screw against the threaded portion.