Abstract: Casper pins have a single uniform length and are inserted to different depths into vertebrae using different depth insertion tools. The Casper pins have a sharp threaded tip and a drive head at the opposite end. The Casper pins are used with insertion tools that are each marked with a different insertion depth. The insertion tools each have a tubular front section and a driver within the tubular section and a handle for rotating the insertion tool. Once the proper insertion depth is determined, the Casper pin is placed into the corresponding insertion tool. Using the insertion tool, the tip of the Casper pin bores into the vertebra and when the designated insertion depth is reached, the driver of the insertion tool is separated from the driver head of the Casper pin. Thus, the Casper pin cannot be inserted beyond the designated insertion depth of the insertion tool. The process is repeated for the adjacent vertebrae so that two Casper pins extend from the patient.