Abstract: An adjustable length orthopedic device comprising: (i) a shaft having a longitudinal axis extending from a proximal end of the shaft to a distal end of the shaft, comprising an exterior having a diameter smaller than the medullary cavity of a bone within which at least a portion of the shaft is configured to reside, wherein the shaft comprises at least a portion of an adjustability mechanism located at said proximal end; (ii) a rod comprising a proximal end having at least a portion of an adjustability mechanism complementary to the adjustability mechanism of the shaft, wherein the adjustability mechanism of the shaft and the adjustability mechanism of the rod are configured to engage with one another in an adjustable manner; and (iii) a locking mechanism positioned at the intersection of the shaft and the rod configured to prevent rotation of at least one of the shaft and the rod.