ACL Repair

The anterior cruciate ligament (ACL) stabilizes the knee to prevent unwanted movement of the bones that meet to form the knee. ACL injuries occur most often during athletic activities. When the ACL is injured, it may require surgical repair to restore the knee's stability and normal function. ACL reconstruction has become a safe and common knee procedure. Today, ACL injuries are no longer devastating to knee function. New technologies and surgical techniques combined with aggressive postoperative care and therapy allow a full return to normal activity.

The knee joint

The knee, which is the largest joint in the body, is considered a "hinged" joint since it is designed to allow the knee to flex (bend) and extend (straighten). The knee is formed by the femur (thigh bone), tibia (shin bone) and patella (kneecap). Each bone is covered with a layer of smooth cartilage, called articular cartilage.

The knee maintains its stability through a series of ligaments that act like rubber bands to allow motion while maintaining proper orientation of the bones. Both the anterior cruciate ligament, or ACL, and the posterior cruciate ligament (PCL) stabilize the knee. The ACL and PCL cross each other in the center of the knee. The ACL is tightest when the leg is straight, and the PCL is tightest when the leg is flexed. The ACL, which runs from the front of the tibia to the back of the femur, prevents the tibia from gliding forward. The PCL prevents the tibia from gliding backward.

Treatment

If you have suffered an ACL injury, treatment depends on many factors, including your lifestyle. Your expectations for knee function or performance may play a role in determining whether reconstruction is needed. For example, an active person may require surgical treatment to obtain the knee stability needed to continue their activities.

With an ACL tear, your knee will be unstable. This instability will cause your knee to "give out," which will significantly influence knee function. If therapy and the use of a special ACL brace do not improve the stability of the joint, your physician may recommend surgical reconstruction. The physician will also consider whether there are additional knee injuries which make surgery necessary, such as a meniscal tear.

Surgery

If surgery is required, the amount of time between your injury and when the reconstruction is performed will be decided by your surgeon. Your doctor will discuss whether your procedure will be performed on an outpatient basis or if a hospital stay will be required; fully explain the procedure; discuss anesthesia options; and explain the risks and benefits of surgery.

Physical therapy will be started before your surgery. This will help you learn the exercises you will need to perform during the initial phases of recovery after surgery. Physical therapy will focus on the following goals:

• establishing a full range of motion (bending and straightening)

• reducing swelling in your knee

• strengthening the musculature surrounding your knee

During surgery, your surgeon will examine your knees to compare the stability of your injured knee to the other knee. After this examination, your injured knee will be evaluated with the help of an arthroscope. The arthroscope is a tiny illuminated fiberoptic camera that is inserted into your knee through very small incisions, allowing the surgeon to see the interior of your knee on a video monitor.

If ACL reconstruction is indicated, the surgeon will use the arthroscope to perform this procedure through very small incisions. Reconstruction usually involves replacing the damaged ligament with a tendon graft. The graft is usually obtained from the central third of your patellar tendon, or from a portion of your hamstring tendons. The graft will be placed in your knee in the exact location of your natural ACL.

After the arthroscopic evaluation, two small tunnels will be made. The first tunnel is placed through the tibia, and the second will be in your femur. This prepares your knee for graft placement. The graft is pulled into place through the tunnels in the exact position of your ACL. After the graft has been inserted into the new tunnels, it is fixed in place. This will secure the graft until complete healing can take place.

Recovery

After your surgery, you will awaken in the Post-Anesthesia Recovery Room where you will stay until you recover from the anesthesia, are breathing well, and your blood pressure and pulse are stable. It is normal to feel pain and discomfort after surgery. Pain medication and anti-inflammatory medication will be given to you after your surgery to ease your discomfort and swelling.

Your knee will be in a post-operative leg brace or knee immobilizer to limit motion. A cold pack, fluid-filled wrap or a continuous circulating cold therapy device will be placed around your knee to provide compression and cooling and control your inflammation, pain and swelling. Special hose or stockings will cover your injured leg to prevent blood clots. Your surgeon will tell you how long the hose should remain on your leg, usually from 10 to 14 days.

In some cases, your surgeon may recommend the use of a Continuous Passive Motion (CPM) machine. The CPM machine will establish your knee motion in the days following surgery. You will be instructed on how to use the machine. It is likely that you will also be directed to use a cooling system on your knee for approximately 30 minutes each hour. You will be instructed to keep your knee elevated above your heart as much as possible.

Crutches will be provided and will be needed for the first 10 to 14 days. You may put weight on your knee when it is comfortable for you. Expect to feel weak for a few days after surgery.

On the day after surgery, you may change all of your surgical dressings except for the steri-strips. The steri-strips are tape strips that are placed directly on the incision. You can expect some bleeding from your incision, which should stop in 24 to 48 hours. Be sure to keep your wounds clean and dry for 10 to 14 days.

Resuming Activity

A specific exercise program recommended by your doctor should be started the day after surgery. The exercises are designed to reestablish range of motion and strength after ACL reconstruction.

After your ACL reconstruction and rehabilitation program, you can expect to return to an active lifestyle. Some surgeons may recommend a functional knee brace for a period of time after surgery and possibly for extended use during sports-related activities. Your physician will track your progress and make recommendations during a follow-up appointment.