A screw assembly and method developed for the fixation of femoral neck fractures without interruption of the growth process is disclosed. The screw assembly includes a male component that is attached to the lateral cortex and a female component that is attached at the proximal epiphysis. Anchorage of the components is achieved through screw-type fixation. The screw has a built-in feature that allows for free extension of its length as the fracture site or the slipped capital physeal plate heals and normal patient growth continues. Stable fixation and rotational stability are created at the fracture (slip) site while avoiding compression forces, thus avoiding premature closure of the physeal plate.