A device for insertion into a gap between adjacent, spaced apart bony elements includes an adjustable length interconnecting member having a distal and a proximal retention plate secured to opposite ends of the interconnecting member. The distal retention plate has a non-rotated position and a plurality of rotated positions. The non-rotated position aligns the distal retention plate with the gap prior to and during insertion of the distal retention plate into the gap. The distal retention plate is rotated after it has exited the gap on a distal side of the gap to prevent its return into the gap. The proximal retention plate is misaligned with the gap so that it cannot enter into the gap. The rotated distal retention plate cooperates with the proximal retention plate to hold bony elements such as adjacent vertebral bodies in a stable relationship to one another when the interconnecting member is shortened.
