An autograft means that the graft material is taken from the patient and not from a donor.
Bone-patellar tendon-bone graft
In a bone-patellar tendon-bone (B-PT-B) graft a strip of patellar tendon is taken, usually from the same knee (but it could be from the good knee) so that at the upper end there is a piece of bone from the patella and at the lower end there is a piece of bone from the tibia. The chunk of bone at each end allows a strong fixation to be achieved, as the bone heals onto the bone in the graft tunnels. The downside of this graft is that the patella and patellar tendon are weakened. There is some regeneration of these structures, but complications such as patellar fracture are possible.
This graft was known for many years as the 'gold standard'.
Four-strand semitendinosus-gracilis hamstrings graft
The use of the hamstrings tendon followed the use of the bone-patellar tendon-bone graft as it caused less problems at the site of graft harvest. The tendons of the semitendinosus muscle and the gracilis muscle are harvested and then folded in half, creating four strands which are then sewn to one another to create a shorter but strong graft material. There is no bone block on either end, so the fixation is very different from the B-PT-B graft, and may involve for example an endobutton or a transfixation device on the femoral side and an interference screw on the tibial side.
The quadriceps tendon above the patellar can also be used as a cruciate graft. Unlike that bone-patellar tendon-bone graft from below the patella, the quadriceps tendon has a bone plug from its patellar attachment, but the other end has none. This graft tends to be reserved for revision (repeat graft) surgery rather than for the original cruciate reconstruction.
Xenografts are seldom used. A xenograft is a graft harvested from an animal.
Synthetic grafts are still used in certain circumstances, but seldom. They were commonly used in the 1980s.