There’s still no clear-cut, single answer to what type of graft should be used for anterior cruciate ligament (ACL) reconstruction. Each one has its advantages and disadvantages. A recent review of studies published on graft choices may offer some insight.
Before launching into all their findings, it might help others reading this to understand there are allografts and autografts. Allografts refer to tissue from a donor bank. The major disadvantage of an allograft is the body’s tendency to reject tissue it considers “foreign” or “nonself.”
But the advantages are great in that the patient does not suffer pain or infection at the donor site. There is a faster healing time with only one wound to heal. And for some people for whom appearances are important, one less scar is worth the risk of using someone else’s tissue for the procedure.
Autografts refer to tissue harvested from the patient. There are three places the autograft (donor) tissue usually comes from: 1) bone-patellar tendon-bone (BPTB), 2) hamstring tendon, and 3) quadriceps tendon. As you might guess from what has been said so far, the donor site can cause a more painful response than even the primary surgical site.
Patients who have tendon harvested from the front of the knee (two of the three options) can end up with pain along the front of the knee. The painful symptoms can be severe enough to keep them from being able to bend the knee fully or kneel down. That may not sound like much of a problem until you can no longer bend down to tie your shoe, tend a garden, play with grandchildren, or slide into home plate for an athlete.
To help compare each technique used from study to study, the authors of this study used seven basic measures. These included knee stability, leg strength, function, return-to-sports, patient satisfaction, complications, and cost. Here’s what they found to help answer your question.
When it comes to post-operative knee joint stability (joint “give”, laxity, or looseness versus tightness of the joint) it looks like there’s no difference between allografts and autografts. The primary difference is in terms of rupture rate. Improper preparation of allografts (e.g., sterilization, drying) can result in more graft ruptures years later compared with autografts.
Concerning muscle strength. There is agreement among studies that quadriceps strength seems to be equal among the various autografts. The hamstring muscle group is more likely to lag behind in recovering full strength, especially for patients who have a hamstring autograft.
Return of overall function seems to be equal among all graft types. But return-to-sports varies widely. The majority of patients (75 per cent) get back to playing but not all return to their preinjury level of participation. Some athletes have to gear down to a lower intensity level of activity while others change the sports activity altogether.
One more area of concern and comparison is complications (e.g., pain, infection, graft failure or rupture). Most patients expect a certain amount of pain right after surgery. But when pain lasts months-to-years later, this symptom becomes a complication. Kneeling pain persists more often with patellar donor grafts. Other long-term annoying symptoms at the harvest site can include numbness, tenderness, or irritation.
Results also showed that infection rates are not higher with allografts. Disease transmission from allograft (donor) tissue (e.g., hepatitis, HIV) occurs in less than one out of every 1.6 million patients.
Finally, graft failure or rupture is more likely occur when there is significant joint laxity (looseness) after surgery. Another significant risk factor is return to sports that require sudden turns or changes in direction (pivoting), sidestepping, and jumping. Studies show that younger, more active patients are the most likely to experience ruptures with an allograft.
In the end, patient satisfaction is rated high (in the 90 percentile) no matter what type of graft is used.