A tether assembly may be attached to a bone to correct a rotational deformity. The bone may have a growth plate that separates a first section of the bone from a second section of the bone. The tether assembly may have a tether member with a first end, a second end, and a central portion extending between the first end and the second end. The first end may have a closed outer wall that defines and fully bounds a first aperture. The second end may have an open outer wall that defines and partially bounds a second aperture. The open outer wall may define a slot in communication with the second aperture. The first and second ends may be securable to the first and second sections of the bone via coupling members inserted through the first and second apertures and anchored in the first and second sections, respectively.