Anterior cruciate ligament reconstruction (ACL reconstruction) is a surgical tissue graft replacement of the anterior cruciate ligament, located in the knee, to restore its function after an injury. The torn ligament is removed from the knee before the graft is inserted in an arthroscopic procedure.

Types of grafts
 
Grafts are inserted through a tunnel that is drilled through the shin bone (tibia) and thigh bone (femur). The graft is then pulled through the tunnel and fixated with screws. The two bright objects in this X-ray are screws in the thigh bone (above) and shin bone (below).
Three sources of replacement material for ACL reconstruction are commonly used:

Autografts (employing bone or tissue harvested from the patient's body)

Allografts (using bone or tissue from another body, either a cadaver or a live donor).
Bridge-enhanced ACL repair (using a sponge filled with the patient's blood to stimulate healing and reconnection of the ACL).
Synthetic tissue for ACL reconstruction has also been developed.