Depicts knee injury with surgical reconstruction of the anterior cruciate ligament (ACL). Surgery steps: 1. Using arthroscope, the surgeon removes the badly torn acl; 2. The surgeon creates a vertical incision from the patella to the proximal tibia; 3. The surgeon makes drill holes in the tibia and femur to hold the replacement ligament; 4. A patellar tendon graft is harvested for use as a replacement ACL; and 5. The surgeon pulls the graft into place through the drill holes.