ACL GRAFTS: Gerald Yacobucci, M.D.
Surgery for the torn Anterior Cruciate Ligament (ACL) has a long history in the orthopedic sports medicine spotlight. We have gone through many phases in our understanding of the importance of the ACL in the active patient’s knee.
We learned early on that the torn ACL did not have the capacity to heal due to its poor blood supply and the hostile healing environment in the knee joint. Initially, we thought it was expendable and therefore could be left alone when torn. Those patients didn’t do well.
We then decided the torn ACL could be repaired…stitched together…most of them failed. Next we tried replacing it with artificial substitutes…gortex and carbon fiber grafts…those lasted a very short time before rupturing and were difficult to remove.
Finally, the biological graft (human tendon) was found to have all the necessary traits to replace the torn ACL and, if properly placed in the knee, could provide the function necessary to restore stability to the active patient’s knee.
Graft choices today involve either an autograft (the patient’s tendon, typically from the surgical leg) or an allograft (from a deceased human donor, cadaver tissue).
The most popular autograft is the Patellar Tendon (Middle One-third Bone-Tendon-Bone). This is the Gold Standard of grafts as it was the first to become popular and the only one to provide bone-to-bone healing at each end of the graft. One negative is patients often get patellar pain for a period of time after the surgery. The midline incision (scar) is sensitive to kneel on and the donor site weakens the patella (making a patella fracture very challenging to treat). This is the graft of choice for the large contact athlete (ie. football lineman) due to its predictable strength and stability characteristics.
Another good autograft is the Semitendinosis-Gracilis graft. Both are medial hamstrings which can be harvested through a small incision which is well away from the midline (better cosmesis and easy to kneel on). The hamstring muscles adapt very well and fill in the donor defect with strong collagen tissue…avoiding permanent muscle deficits. At one year follow-up, most studies show this graft achieves comparable strength to the Patellar Tendon Graft. This graft makes the most sense for an athlete under age 25 whose emphasis is on speed and agility (less patellar pain and patellar tendon pain).
Lastly, the Allograft…..tibialis anterior and middle third bone-patellar-bone being the most popular. These two are grouped together are far as strength and healing traits. Their main advantage is eliminating the pain, scarring and weakness that goes with autografts….making the recovery from ACL surgery easier. Two concerns arise with these grafts. Disease transmission is a theoretical concern and has been thoroughly addressed by the human tissue bank industry. Meticulous detail goes into the harvesting, testing and preservation of this tissue which currently is felt to carry with it a risk for disease transmission of less than one in one million. The second issue (borne out in several recent studies) is one of graft rupture (failure). This has been shown in several studies to be significantly higher in male patients under the age of 25.
I hope this brief overview of a very complex topic improves understanding for the patient and serves as a starting point for discussion between the patient and their surgeon regarding ACL graft choice.
If you are experiencing knee pain call one of our experts at TOCA by calling 602-277-6211 or visiting our website to learn more atwww.tocamd.com!