Treatment Choice - Treatment Choice | Compare Prices | Find Hospital | If you tear the anterior cruciate ligament in your knee, you may need to have reconstructive surgery.<br/>The anterior cruciate ligament (ACL) is a tough band of tissue joining the thigh bone to the shin bone at the knee joint.<br/>It runs diagonally through the inside of the knee and gives the knee joint stability. It also helps control the back-and-forth movement of the lower leg.