What is the Best ACL Reconstruction Technique?

Anterior Cruciate Ligament (ACL) tears are one of the most common sports injuries. ACL injuries typically occur in cutting and pivoting sports such as skiing, football, and soccer. It is estimated that approximately 60,000 to 75,000 ACL reconstructions are performed each year in the United States. Despite the high volume of cases, there is still debate among ACL surgeons regarding the best ACL reconstruction technique. ACL Specialist, Dr. Richard Cunningham has seen techniques evolve over the last 2 decades, but he highly recommends ACL reconstruction utilizing a portion of one’s quadricep tendon for a number of reasons. Dr. Cunningham has been performing this technique in his practice for nearly 10 years with excellent patient outcomes. He was one of the first knee surgeons in Colorado to perform this surgery.

One of the most important considerations in ACL reconstruction surgery is what sort of tendon graft will be utilized to replace one’s torn ACL. Factors to consider are minimizing morbidity from harvesting a graft from the patient and choosing a graft with the lowest re-tear rates. An autograft (from the individual) or allograft (from a cadaver) graft can be used. Although there is less morbidity when using an allograft, numerous studies have shown inferior results when comparing an allograft to an autograft. Many studies have shown significantly higher re-tear rates in allograft ACL reconstructions compared to autograft ACL reconstructions.

As for autografts, there are several options. A surgeon can utilize a portion of one’s patellar tendon, one or two hamstring tendons doubled over, or the central portion of the quadriceps tendon. Due to better stability, lower re-tear rates, and less donor site morbidity than other autografts, Dr. Cunningham highly recommends utilizing a quad tendon autograft for ACL reconstruction. In fact, the use of a quad tendon graft is growing in popularity year by year amongst surgeons who do a high volume of ACL reconstruction surgeries.

What are the Benefits of ACL Reconstruction Using a Quad Tendon?

A quadriceps tendon graft has several anatomical advantages. It is nearly twice as thick (measured at a cross-section) compared to a patellar tendon. It is best to utilize a graft that approximates the size of your original ACL and a quad graft accomplishes this. A quad graft has over 80% more tendon fibers or collagen compared to a patellar tendon graft.

The quad graft is the strongest graft as demonstrated in several studies, stronger than hamstring or patellar tendon. With a hamstring graft, most ACL surgeons are doubling over both the semitendinosus and the gracilis tendon to create a graft comprised of 4 strands of tendon. This graft is typically 7-8mm in diameter. The quad tendon is reliably a 9-10mm graft. Furthermore, the quad is one piece of tendon just like a native ACL, whereas a hamstring graft is 4 strands of separate tendon.

There are several orthopedic studies that support quadriceps tendon over other graft choices including:

Post-surgically, the use of the quadriceps tendon graft in anterior cruciate reconstruction has some benefits:

As much as a 90% increase in load function compared to a patellar tendon graft.
A less intrusive harvesting procedure, without the need to take portions of bone from the patella and tibia, which results in less kneeling pain in the future.
Full extension is achieved sooner after surgery.
Laxity is minimal, with good knee stability
Lower incidence of tendinitis.

ACL Surgery with Patellar Tendon Graft vs Quadriceps Tendon Graft?

When considering a patellar tendon graft versus a quadriceps tendon graft for ACL surgery, the main two benefits of selecting the quadriceps tendon graft over a patellar tendon graft are less harvest site problems and better patient outcomes. When harvesting a portion of the patellar tendon, the surgeon also has to remove a portion of the bone of the knee cap as well as a piece of bone from the top of the tibia. This must be done for patellar tendon grafts as this tendon is much shorter than a quadriceps tendon. The attached fragments of bone are required to give the patellar tendon adequate length. After taking these portions of bone with the patellar tendon, there is a high incidence of patients who continue to have pain around their kneecap when kneeling and this problem can persist indefinitely. With a quad graft, there is no need to remove any bone with it as the quad tendon is sufficiently long. As a result, there is not the kneeling pain with a quad graft that is often seen after harvesting a patellar tendon graft. As a result, there is often less pain with a quad graft and patients recover quicker. Another advantage of a quad graft over a patellar tendon graft is that a quad graft is nearly twice as thick and stronger than a patellar tendon graft.

Best ACL Graft for Female Athletes

Female athletes have a greater risk of an ACL tear compared to their male counterparts. To learn more about female athlete ACL tears, please visit our article: Female ACL tear. When deciding the best ACL graft for female athletes, some things to consider are:

Allograft – Higher failure rates and reports of graft stretching over time.
Hamstring autograft – Potential post-surgical pain around the harvest site. Re-tear rates are higher than quad tendon ACL grafts and more likely for female patients, with up to 20% re-tearing in female athletes. Some studies have also shown a residual strength deficit in the hamstrings compared to the strength of one’s normal hamstrings after harvesting this graft.
Patellar tendon autograft – A more invasive harvest with the need to take bone from the patella and tibia resulting in a higher incidence of kneeling pain long term. Higher incidence of numbness along the front of the knee.
Quadriceps tendon autograft – Studies show great results. Stronger graft with quicker recovery at the harvest site.

How is ACL Reconstruction with Quad Tendon Performed?

ACL reconstruction utilizing a quad tendon is performed by ACL doctor Dr. Cunningham on an out-patient basis and does not require an overnight stay. General anesthesia as well as a nerve block will be administered by the anesthesiologist. Arthroscopic portals are placed about the knee. The knee is thoroughly evaluated. Any meniscus tears are repaired. Dr. Cunningham then removes the injured ACL unless it is amenable to a primary repair (see article on primary ACL repair). The quadriceps tendon is exposed and the central third of the tendon is harvested. Once the graft has been harvested, both ends of the graft are secured with high strength suture and small fixation devices. Bone sockets are created in both the femur and tibia in the exact location where the original ACL once attached. The graft is fixated into these bone sockets. The quad tendon harvest site is repaired so that it heals appropriately. The incisions are all closed and dressed. A hinged knee brace is applied on the knee. The patient is moved to the recovery room. The procedure normally requires an hour but there is also some set up and take down time in the operating room. Patients will be released from the surgery center a few hours following surgery when their pain is controlled, when they are able to eat and drink, when they can urinate, and when they can mobilize with crutches.

Ride the road to recovery

Dr. Cunningham utilizes cutting edge treatment techniques to get patient’s back on the road quicker.

What is Recovery Like After ACL Reconstruction with Quad Tendon?

Due to the minimally invasive nature of the procedure, patients can expect a quicker return to full function compared to an open procedure.

The goals of the initial recovery period include:

Elevating and icing the knee to decrease knee pain and swelling
Starting passive and active knee range of motion exercises
Trying to achieve full extension or straightening of the knee
Weight bearing as tolerated with crutch assistance
Starting prescribed physical therapy exercises

Patients can spin on an exercise bike as soon as tolerated with minimal resistance. By the third week, full weight bearing with a normal gait is the goal. By the fourth week gentle strengthening is started. By the eighth week, patients can ride a bike outdoors. By the fourth month, patients can start jogging. A return to cutting and pivoting sports to include soccer and skiing is 8-9 months as it takes this long to achieve full strength. Historically, ACL surgeons would try to get athletes back to these high level sports by 6 months from surgery, but there was found to be a significant re-tear rate, so most ACL surgeons now wait until 8-9 months to clear patients for these sports.