Anterior Cruciate Ligament (ACL) Sprain

The anterior cruciate ligament (ACL) is the most common ligament injured in the knee.  Approximately 250,000 people sustain a torn or ruptured ACL every year in theUnited States.  The ACL provides stability and helps control excessive motion in the knee.  After tearing the ACL, the patient may elect to treat the knee surgically or non-surgically.

Non-operative:  After electing to not have surgery, there are several goals that need to be accomplished in order to improve function and avoid further damage to the knee.  The goal of physical therapy is to strengthen the muscles around the knee to make up for the absence of the ACL.  In the early stages of rehab, you will work to re-establish full range of motion in the knee, decrease swelling and pain, perform a good quad set (contraction of the muscle), and achieve normal gait.  Then you will progress to strengthening of the knee, hip, and ankle.  Strengthening the muscles of the hip and ankle are important to help control the thigh and leg bones, which make up the knee joint.  Balance and stability exercises are also necessary to prevent further cartilage damage in the absence of the ACL.  Finally, you will work on training specific to your sport or work activities to help you return to normal function.  After completing physical therapy, a program of strength and stability exercises for your legs should be performed 2-3 days a week throughout your life to maintain maximum knee stability.

Pre-operative:  Once you have elected to have surgery, your physician might want you to attend therapy for a few weeks before surgery.  In most cases, patients who have surgery do better if they wait for the swelling to decrease, exercise before surgery to regain strength and full range of motion in the knee, and then surgically repair the knee.  Physical therapy can help achieve these goals and will also allow you the opportunity to become familiar with the exercises you will perform after surgery.

Post-operative:  After surgery, the initial goals of rehab are similar to the pre-operative goals: restore full knee range of motion, decrease pain and swelling, achieve good quad muscle contraction, and walk normally.  It is very important to work on increasing motion in the knee, especially extension (straightening the knee).  You have approximately 30-45 days to regain this motion before the extension range is set and may never improve.  This is the #1 goal.  Most patients do not have difficulty regaining the flexion (bending) motion in the knee, as long as the therapy exercises are performed.  Also, it is necessary to re-train the quad muscle to fire and contract appropriately.  This is accomplished by performing quad sets.  Normal gait without crutches should be achieved in the first 2-3 weeks post-op.  You should not stop using the crutches until you can walk without a limp.  When you are able to put full weight on your leg without pain or difficulty, you may also begin to drive a car, but the final decision to drive is up to you and your physician.

For the first 3 months after surgery, resistance exercises are gradually increased to strengthen the knee and muscles of the leg.  During this time, you will also focus on increasing functional activities, including squatting, climbing stairs, etc.  Your therapist will progress you with exercises that address your individual deficits and needs, leading to return of normal activity for most patients at about 6 months, but the time frame may range from 6-12 months.  Your therapist and physician will determine when it is appropriate to return to full activity.