So once somebody has ruptured their ACL there are 2 options open to them:
1. Do nothing- it is not compulsory to have an ACL reconstruction once it has ruptured. There are plenty of people that manage an ACL rupture conservatively quite successfully. With the right physio rehabilitation, eventually activities such as cross trainer, exercise bike, swimming and specific weight training are achievable. However, it is unlikely that someone deficient in an ACL would be able to play team sports such as soccer, rugby, netball etc or go skiing without the aid of a supportive brace. A person who has ruptured their ACL should ask themselves the question- what actives do I want to do for the rest of my life and then make their decision on whether to go ahead with an ACL reconstruction or not.
2. An ACL reconstruction- there are 3 main current methods of reconstructing the ACL:
a. Hamstring graft- The hamstring is the main muscle at the back of the thigh and is responsible for flexing (bending) the knee and has a role in assisting the gluteal muscles in extending the hip. A portion of the semitendinosus and gracilis tendons are taken to form the new ACL graft.
A crucial thing to remember with both the Hamstring and Patella Tendon graft is that the moment the living tissue is taken out of the body during the operation, it starts to die. Since it is tissue from the patients own body, the immune system does not tend to attack the new graft as a foreign invader. However, there is a process over the first 9 weeks post op where the more contractile tendon tissue is slowly dying to be converted into a stabilising ligament tissue. This is important information for the physio to remember because as such at 9 weeks the new graft is at its weakest.
b. Patella Tendon graft- The patella tendon is an extension of the quadriceps muscle and absorbs the the knee cap before attaching onto the front of the shin bone. During the procedure
The benefits of the patella tendon graft is that the bone plugs taken from the bottom of the patella and the top of the tibia give the new ACL graft a more sturdy boney anchor to assist in the recovery. Also the natural length of the patella tendon is coincidently the same as the ACL and so there is no need to accurately cut the graft to the precise size as in the Hamstring graft.
The disadvantages of using the Patella tendon graft is that it can difficult to kneel on the operated knee post surgery.
c. LARS (Ligament Augmentation & Reconstruction System)
This is the most recent development in ACL reconstruction. The basic premise of this system is that a synthetic material is used through the stumps of the two ruptured ends of the pre existing ACL. This trellis then allows the 2 ruptured ends of the ACL to grow along the synthetic LARS like a vine until the two ends are reattached.
The advantage of this system is that the rehabilitation is generally slightly quicker as you’ve got a nice stable synthetic ligament that doesn’t need to change from being a tendon structure into being a ligament structure like the patella tendon and hamstring graft technique.
On the flip side, as it is a relatively new surgical procedure there has not been any long term studies on the LARS so nobody really knows how comparable this cutting edge technique will be compared to the more traditional hamstring or patella tendon graft. Furthermore, seeing as the LARS is a foreign tissue, the bodies immune system has the potential to reject it. Finally, there has been some high profile failures of the LARS in elite athletes so all in all I would say watch this space.
There is one more less commonly used option for ACL construction and that is using a tendon from a cadaver. This is pretty uncommon nowadays and the main reason for doing this would be if the patient had already had surgery on their hamstring/ patella tendon or had poor quality tissue. This also has the same potential problems as the LARS as it is a foreign tissue so the body may well reject it.
Post operatively, the surgeon stitches the main 3 incision sites and covers them with plasters. There is then a large crepe bandage placed around the knee and the patient is encouraged to immediately start bending and straightening the knee, get the quads switching back on again and then encouraged to walk on crutches as pain allows. However due to post op pain, the patient will probably only want to weight bear on operated leg for balance and not actually put too much weight on it.
Although most surgeons will have their own preference as to which of these 3 surgical procedures to perform, they should offer the patient any of these 3 surgical options and talk them through the pro’s and cons of all 3 techniques. On the other hand, if someone was to ask for my personal opinion, my particular preference would be the hamstring graft for the best result but it is only marginally more my preference over the patella tendon graft.