patellar tendon graft v. hamstring graft v. allograft

surgery is set for this coming tuesday (6 days and counting) and the last real decision i had to make was which kind of graft i'm interested in using. ligament tissue (such as in an ACL) is elastic, therefore, it's impossible for the body to naturally heal the ligament and maintain elasticity. the surgical procedure seeks to replace the ACL with a graft from somewhere else. there are three main options for this type of procedure and i've been researching them all to figure out what the best one is going to be.

patellar tendon autograft
your kneecap is also called the patella. it's connected to your upper and lower leg bones via some tendons. in a patella tendon autograft, the surgeon removes the central third of the tendon along with a bone fragment on each side that the tendon is connected to (this procedure is called a bone-tendon-bone procedure). the surgeon then drills holes in both bones, runs the ligament through the holes where the ACL should be, and secures the bone fragments to the bone using screws.

pros:
- this is by far the most traditional of the techniques. many call it the "gold standard" of ACL grafts.
- it heals pretty fast because the bone fragments fuse relatively quickly to your bone
- the technique for harvesting the patellar tendon can leave you in pain

cons:
- people tend to complain of pain in their knee when they kneel and sometimes when they squat too
- it requires a very precise surgical technique and is not forgiving of surgical mistakes

hamstring autograft
in this technique, the surgeon removes part of tendon that connects your hamstring (the underside of your thigh) to the bone. the surgeon then folds the tendon several times and stitches it together to make a strong graft, drills holes in your bones and screws it in place of your old ACL.

pros:
- the technique required for this surgery is a lot less difficult
- typically no knee pain when kneeling

cons:
- unlike the patellar tendon graft, there are no bone fragments on the end pieces of the graft, meaning that the recovery time for the graft to fuse into the bone is a lot longer, because it's trying to connect soft tissue to hard tissue
- it can tend to weaken your hamstring, so you need to do a lot of strength training to restore your hamstring strength.

allograft
an allograft is a graft taken from a cadaver donor. it's secured using screws into your knee, just like the other techniques.

pros:
- since the surgeon does not need to harvest the graft from your body, there is a lot less pain and the technique is easier and faster.
- your knee becomes part zombie, which is sweet.

cons:
- there is a small risk of infection or disease transmission because you are implanting somebody else's tissue in your body.
- there is little data on the long term strength of the graft
- the process required for sterilizing the graft using irradiation tends to weaken the graft, so it has less elasticity than a normal ligament.
- it takes longer for your body to vascularize the tissue (vascularization is when your blood vessels grow through the tissue, basically making it a part of your body).

based on all this information, i've decided to go with the hamstring graft, as it seems to be pretty solid for long-term use and doesn't result in pain when kneeling. i'm also authorizing my doctor to use the cadaver graft as a backup plan if he decides that my hamstring tendon is not suitably long enough after he opens me up (which is occasionally a problem with the hamstring procedure).