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Anterior Cruciate Ligament Reconstruction (ACLR)

See Also Patient ACL Guide

Dr. Prodromos has developed an arthroscopically-assisted double bundle anatomic technique using mini-incisions to reconstruct torn anterior cruciate ligaments. This procedure uses hamstring grafts to replace the injured ligament and is performed on an outpatient basis. We have published an eight-year follow-up study in one of the world’s leading journals of 150 hamstring ACL reconstructions without a single graft failure.

ACLR side drawingACLRXray

Definition of anterior cruciate ligament:

The structure that holds the knee together during pivoting and jumping. When it is torn, the knee may be unstable during these activities.

Consequences of a torn ACL:

When the knee “goes out,” cartilage is often torn. This eventually can result in arthritis of the knee. In severe cases, total knee replacement may be necessary to restore function and relieve pain.


A recent study from our clinic confirms that the KT 1000 arthrometer is 100% diagnostic of ACL tears. MRI is an option as well. However, MRIs can give a false negative result. In our study, MRIs erroneously showed in about one-fifth of our ACL patients, that the ACL was intact when it was in fact torn. For this reason we only perform MRIs in special circumstances, or if the patient requests.

For more information about diagnosis go here.

Anterior Cruciate Ligament Reconstruction:

Repair of a torn ACL is ineffective. But reconstructing the ACL with a tendon graft reliably restores knee stability. At Illinois Sports Medicine we use hamstring grafts exclusively for this procedure.

Types of Grafts:

Hamstring Tendon: A helper hamstring tendon and a helper adductor tendon are removed from the thigh and used to make a new ACL. With proper rehabilitation, there should be no strength deficit or other problem as a result of removing this graft.

Patellar Tendon: Patellar tendon grafts with a piece of the patella and a piece of the tibia are also used successfully by many orthopedists to reconstruct the ACL.

For more information about graft types go here.

Why We Use the Hamstring Graft:

The hamstring graft is stronger than the patellar tendon graft. Its material properties (modulus of elasticity) also more closely resemble the native ACL than the patellar tendon graft. On rare occasions, the patellar tendon graft can be associated with complications. These include fracture of the patella (as happened to all-pro NFL receiver Jerry Rice) or rupture of the remaining patellar tendon. No complications have been found to occur from taking the hamstring graft. Additionally, patellar pain and stiffness are generally found to be higher using the patellar tendon graft than the hamstring graft. Both the hamstring graft and patellar grafts are excellent procedures when properly performed.

Type of Procedure:

The surgery is done on an outpatient basis at a hospital or surgicenter. The patient goes home later on the same day the procedure is performed.


General anesthesia (putting the patient to sleep) is the usual anesthetic method. It is also possible for the patient to have an injection into the lower back for spinal or epidural anesthesia. Anesthesia injected into the lower back puts only the legs to sleep.

Surgical Mini-Incision Hamstring Harvest:

Dr. Prodromos developed a mini-incision technique he uses for this procedure. He uses a small incision hidden in the back of the knee and a small incision over the upper shin. Both are only about one inch in size (in heavier patients, larger incisions are used). One year after surgery both are usually inconspicuous and often nearly invisible.

incision scar frontincision scar back

Surgical Notes:

A tiny button is implanted on the thighbone and cannot be felt. A titanium screw is implanted in the tibia–the leg bone. This screw may be findable by rubbing over it, but in our study of 150 consecutive cases no patient has wanted it removed or had complaints regarding it. Most of the surgery is done arthroscopically, using a small operating telescope inserted through three ΒΌ-inch punctures into the knee. No knee incision is otherwise used. The surgery takes about 90 minutes.

Associated Injuries:

In about half of the cases, a meniscal cartilage injury will be found. This is easily trimmed or repaired as needed at the time of surgery. Sometimes defects in the coating of the bone, called the articular cartilage, are found. These defects are smoothed, or a microfracture may be performed to regenerate new cartilage. A subsequent autologous chondrocyte implantation may also be necessary in rare instances.

Post-Operative Rehabilitation:

After surgery, weight bearing and leg motion are rapidly initiated. Most people can return to school or sedentary jobs within a few days of the surgery. Physical therapy will be prescribed to restore motion and strength. In most cases, full sports activities are resumed in eight months.

For more information about post operative rehabilitation, go here.


Infections can occur in about one per cent of cases. In our recent studies, no infections were found. A rare occurrence could be stiffness, which might require an additional procedure be performed. Other rare complications such as nerve injury or reflex sympathetic dystrophy also can occur. Graft failure is noted in the orthopedic literature to occur in about five percent of all ACLR cases. In a two- to nine-year follow-up study of more than 200 ACLRs done at our clinic, however, we did not have a single instance of graft failure.

Pain Relief:

Hydrocodone and acetaminophen are used for pain relief in tablet form. Also a special pad and cooler are used to continuously pump ice water around the knee both in the hospital and at home for the first week.

Case Histories:

Go to our case histories for patient #1 and patient #3 to read about patients who had anterior cruciate ligament reconstruction surgery done along with other procedures. Also look at the case history for patient #8 to read about a debridement of a partial tear of an ACL graft.

See These Published Papers for Additional Information:

Controversies in Soft-Tissue Anterior Cruciate Ligament Reconstruction: Grafts, Bundles, Tunnels, Fixation, and Harvest. Prodromos, et al. 2008.

A Meta-Analysis of the Incidence of Anterior Cruciate Ligament Tears As a Function of Gender, Sport, and a Knee Injury-Reduction Regimen. Prodromos, et al. 2007.

A Meta-Analysis of Stability of Autografts Compared to Allografts After Anterior Cruciate Ligament Reconstruction.  Prodromos, et al. 2007.

A Meta-Analysis of Stability After Anterior Cruciate Ligament Reconstruction as a Function of Hamstring versus Patellar-Tendon Graft and Fixation Type. Prodromos et al. 2005

Additional ACL related papers.