What are the Different ACL Reconstruction Techniques?
There are several anterior cruciate ligament (ACL) reconstruction techniques available for treating ACL tears. The most important consideration is the type of graft used to reconstruct one’s ACL. The first choice is whether the graft will be an allograft or an autograft. An allograft is a tendon taken from a cadaveric donor, whereas an autograft is a portion of a tendon harvested from the patient. Dr. Cunningham has done thousands of ACL reconstructions over the last 20 years and strongly recommends against using an allograft for one’s ACL reconstruction, especially in younger more active patients, as numerous studies have demonstrated a higher retear rate when utilizing an allograft. Other studies have shown that allografts can stretch out over time and become incompetent leading to recurrent knee instability. By comparison, a well done ACL reconstruction surgery utilizing autograft has been shown to have very good results, and retear rates are no higher than the rates of tearing the native ACL in one’s other uninjured knee.
There are three main autograft options:
- Patellar tendon – Utilizing a section of the patellar tendon along with a one inch section of bone taken from the patella and a one-inch section of bone taken from the tibia is an autograft that has been used for decades in ACL reconstruction and has a history of long term success. However, the patellar tendon harvest process is painful and there is a higher incidence of pain when kneeling, which can be permanent.
- Hamstring tendon – The hamstring tendon autograft is another good option. It does not require harvesting any bone with it as these tendons are of adequate length. However, women tend to have smaller hamstring tendons and therefore the graft is often smaller than their native ACL. Although there are now techniques to overlap small hamstring tendons thus making the graft larger, there is still a slightly higher retear rate with hamstring tendon ACL reconstructions. Furthermore, there is a higher incidence of persistent hamstring weakness after harvesting the hamstring tendons especially in terminal knee flexion. Finally, in professional athletes, a hamstring ACL graft is not commonly used as there is seen to be higher re-rupture rates and some stretching out of this graft. This may be related to the fact that this graft is multiple strands of individual tendon and not one piece of tendon and also that hamstring tendons are not as stiff as some other tendons.
- Quadriceps tendon – Utilizing a section of one’s quad tendon allows for a large, thick, strong, single strand of tendon graft. A quad graft is nearly twice as thick as a patellar tendon graft. The quad is also a long tendon so there is no need to take sections of bone with it as is the case for a patellar tendon, which is a short tendon. Although patients have to heal the harvest site as with any autograft harvest, there is not seen to be a higher incidence of persistent quad pain or kneeling pain. This graft is a great option for young athletes, whether they be professional athletes or weekend warriors. There is a very low 2 – 3% reinjury rate, compared to a higher re-rupture rate for hamstring ACL procedures.
What is the Best Technique for ACL Reconstruction?
Dr. Cunningham feels that a quad tendon ACL reconstruction technique is currently the best option for most patients who have sustained an ACL tear and wish to resume all their activities. Although the technique has only been widely utilized for the last 10 years, more and more studies support a quad tendon ACL reconstruction. ACL doctor Richard Cunningham, MD was one of the first surgeons in Colorado to adopt this technique. The benefits of this technique include:
- Quad tendon thickness matches the thickness of one’s native ACL
- One solid tendon and not 4 or 5 separate strands of hamstring tendons
- The quad tendon is long enough so that there is no need to take pieces of bone with it on either end as is the case for a patellar tendon graft
- Less invasive incision
- No long term pain with kneeling
- Very low failure rate compared to other options
These benefits are supported in the orthopedic literature and seen clinically by Dr. Cunningham who has done over 1,000 quad ACL reconstruction surgeries. Studies report a 2 – 3% reinjury rate, as compared to a higher reinjury rate for a hamstring autograft. Supporting research demonstrates that young, high demand athletes are shown to experience good to excellent results with the ability to return to their pre-injury activities and with very low complication rates.
What is the Success Rate with Quad Tendon ACL Reconstruction?
In this recent study, “Quadriceps Tendon Graft for Anterior Cruciate Ligament Reconstruction: THE GRAFT OF THE FUTURE!”, reported excellent clinical outcomes using a quad graft. The study analyzed nearly 1,000 grafts, with a mean patient age of 20 years old. They found a low failure rate of 4.2%. Post-op scoring tools found that male and female patients, both young and old, reported high satisfaction with quad tendon ACL reconstruction. Return to activity was rated high. Function, range of motion, and biomechanics, as compared to the untreated leg function were all found to be good.
What is Quad Tendon ACL Reconstruction Recovery Time?
The procedure is outpatient, with patients going home the same day. Patients are instructed to ice and elevate for the first few days, but they can immediately put weight on the knee with the assistance of crutches and a knee brace. Physical therapy is started right away with patients going 2-3 times per week for several months, as well as doing exercises at home on the other days. By 2-3 weeks from surgery, patients are walking without crutches and are out of the knee brace. They are spinning on a stationary bike with minimal resistance in the first 6 weeks. By 8 weeks, patients can ride a bike outdoors. By 4 months, patients can be jogging and hiking. By 6 months patients can snowshoe and nordic ski. To return to high level cutting and pivoting sports such as alpine skiing and soccer, it can take 8-9 months to regain adequate strength to safely do these activities.
ACL doctor Richard Cunningham, MD specializes in the treatment of ACL injuries. He has been utilizing the quad tendon graft for ACL reconstruction surgery for over 10 years with excellent results.