Abstract: An apparatus is provided for use in installing a replacement ligament in substantially coaxial tibial and femoral tunnels formed in a knee joint by drilling upwardly from the anterior surface of the tibia below its plateau, through the plateau, and into the distal end of the femur. The replacement ligament has a leading end portion receivable in the femoral tunnel and a trailing end portion receivable in the tibial tunnel. The apparatus includes a sheath having a leading open end and an opposite end. The sheath has a calibrated scale printed thereon starting at the leading open end. The calibrated scale provides a visual indication of a distance from the leading open end of the sheath. The sheath is configured to receive the replacement ligament therein while the sheath is outside a patient's body with the leading end portion of the replacement ligament adjacent said open end and with the trailing end portion of the replacement ligament disposed toward said opposite end of the sheath.