ACL Reconstruction: How Long Does It Take To Recover?

ACL reconstruction is a medical procedure that repairs damage to an important component of the knee called the anterior cruciate ligament (ACL). The procedure is performed by an orthopedic surgeon who also supervises post-operative rehabilitation and the restoration of your normal knee movement. If you’ve suffered this injury, the experts at Plymouth Bay Orthopedic Associates in Plymouth, MA can repair your ACL and smoothly guide you back to your old best self and your favorite activities.

Meet the ACL

Bones that come together in joints that are meant to flex, such as the knee, elbow and shoulder, are connected to each other by tissues called ligaments. Ligaments hold these bones together even under the unnatural stress of sports and other impactful activity. The ACL is an important ligament in the knee.

The knee is a large, complex joint where three major bones meet. The thighbone (femur) and the shinbone (tibia) are protected by a strong bone called the patella or kneecap. The kneecap provides protection for the other two bones. All three bones are held in place by four different types of ligaments:

Collateral Ligaments

These two ligaments are located on the sides of the knee. The medial collateral ligament runs along the inner edge, while the lateral collateral ligament runs along the outside from the bottom top of the thighbone to the top of the shinbone. Together, the collateral ligaments are responsible for bracing the knee against shock from sideways motion.

Cruciate Ligaments

Inside the knee joint, these two ligaments cross over each other; one in the front (anterior cruciate ligament) and one in the back (posterior cruciate ligament). Together, they are responsible for controlling the forward and back motion in the knee.

The ACL runs diagonally in the middle of the knee and plays an important role in stabilizing the knee joint.

How Does the ACL Get Injured?

Injuries to the ACL can happen for all sorts of accidental or seemingly harmless reasons, such as climbing stairs or walking on unstable terrain. However, the injury is most commonly suffered during sports and fitness activities. Most moving sports that involve jumping, running or contact can cause this injury. A few common contributors to this injury on the court or the field occur when:

  • You quickly pivot from one direction to another
  • You stop suddenly to change direction while you’re in motion
  • You land hard or awkwardly from a jump
  • You make sudden, jarring stops while running
  • You suffer a collision or other impact at the knee

Are All ACL Injuries Alike?

There are different levels of ACL injuries. Some smaller damages to the ACL can heal on their own while others will need medical attention. Doctors rate these damages by the following scale:

Grade 1 Sprain

In this instance, only mild damage has been suffered. You’ve stretched your ACL and there may be pain, but there’s still enough strength in the ligament to keep the knee stable.

Grade 2 Sprain

When the sprain stretches the ACL to the point where it becomes too loose to keep the knee fully stable, it’s a Grade 2 sprain. In reality, this injury is actually considered a partial tear.

Grade 3 Sprain

In this injury, the ACL has been torn. The ligament is no longer able to keep the bones in place, and the knee joint no longer has the integrity to remain stable.

Most ACL injuries are complete or near-complete tears. What’s worse is that a serious ACL tear often means there’s been additional damage to other nearby ligaments or cartilage in the knee. Serious ACL injuries require medical attention and should be treated with surgical correction.

How Do I Know If I Have an ACL Injury?

When you injure your ACL, you’re not likely to miss the symptoms. You’ll feel your knee give out from under you when placed under strain. You may even hear an actual noise when the tear occurs. When this injury occurs, you can usually tell the unmistakable symptoms quickly:

Pain and Swelling

Upon suffering an ACL injury, the knee will experience substantial swelling. In low-grade sprains, the swelling and pain may eventually calm down on their own. However, if you attempt to return to sports before adequate healing, there’s a risk of further injury. The knee will be unstable, and there’s significant risk causing further damage.

Loss of Range of Motion

A healthy knee is able is a complex actor in the body and able to flex in a variety of directions and ranges. When you damage the ACL, you lose some or all of the range of the knee’s movement. You’ll also find that your knee can’t comfortably bear your weight during even low-impact activities, like standing and walking.

Tenderness That Doesn’t Go Away

Pain is hard to ignore, especially during necessary daily activities that have you on your feet. While the effects of a minor knee injury can be temporary and treated with rest and over-the-counter medications, a significant ACL injury doesn’t heal quickly or completely without medical attention.

Instability While Walking

Walking is central to daily activity and more than just the function of steps and strides. Much of our walk quality is actually connected to our neurological systems, which give us cues for balance and stability. A damaged ACL not only causes discomfort during walking: it actually makes walking unstable and potentially dangerous by introducing elements of anxiety and unpredictability to our gait pattern.

When Should I See a Doctor?

The ability to heal adequately from an ACL injury without medical intervention depends on the patient and the severity of the injury. How well and how fast your ACL can heal depends on your activity level and how careful you can be in favoring it until the injury begins to calm down and begin regeneration.

Can the ACL Heal on Its Own?

A minor sprain or small tear in the ACL can often heal on its own. The process isn’t short. Getting back to “normal,” even with this lower-grade injury can take several months. However, without a clinical examination, there’s no way of determining the severity of the injury, so a doctor’s visit is always a good idea. In many cases, the doctor can help some patients with partial ACL tears or unstable knees recover with only bracing assistance and physical therapy.

A complete ACL tear will require surgical correction. Once you’ve torn your ACL, you won’t be able to participate in sports that require a full range of motion or strain on your legs and knees. Even non-athletes with an ACL tear must live with dangerous instability during even normal activities, such as standing and walking.

Patients who don’t adequately look after an ACL injury run the risk of further damage to the knee. Because of the ongoing instability caused the ACL damage, other damages to knee cartilage are not uncommon. This causes long-term risk to the knee that can continue to be troublesome years after the initial injury.

What Is ACL Reconstruction?

An ACL reconstruction is basically a tissue graft. Healthy tissue from elsewhere in the body is used to repair the ACL tear. There are several variations of the procedure that orthopedic surgeons use, and the selected approach is determined on a case-by-case basis. The major fixes include:

Patellar Tendon Autograft

Referred to by some surgeons as the “gold standard” for ACL reconstruction, this procedure is often recommended for high-demand athletes. In this method, a partial segment of the tendon from the kneecap is used to repair the ACL.

Hamstring Tendon Autograft

In this procedure, a tendon from the inner side of the knee is used to create the graft material to reconstruct the ACL. Some surgeons use an additional tendon to reinforce the area, creating a stronger, multi-stranded graft.

Quadriceps Tendon Autograft

This technique is often used for patients who have already failed a more conventional reconstruction. Tendons from the quadriceps (“quad”) muscles, in front of and just above the kneecap, are used In this procedure, usually along with a bone “plug” from the upper end of the kneecap. This provides a larger graft that’s suitable for larger patients.


Allografts are grafts taken from cadavers. These grafts are used for patients who have failed reconstruction before or in surgical procedures to repair or reconstruct more than one knee ligament. When the graft material is obtained from a source other than from the patient, there is less surgical work on the actual patient and smaller incisions, meaning less trauma.

What Happens During Surgery?

In order to prepare for surgery, the patient is usually assigned physical therapy first. A stiff, swollen knee that lacks the full range of motion at the time of ACL surgery may have problems regaining full motion afterward. The doctor will want the knee in the most “presentable” condition before operating.

This pre-operative physical therapy usually takes several weeks from the time of injury to run its course. The doctor may also recommend that your knee be braced during this rehabilitation period. If the knee is in the best possible shape before repair, it has the best chance of regaining full function after the procedure.

During the Procedure

Work begins with a final exam to check for any additional damage that may need attention or work around the knee that has been caused by the ACL tear. From here, the surgeon selects the tendon for the graft and sizes the amount needed for the patient.

Once the graft has been selected and prepared, the surgeon uses an arthroscope to see into the joint. Small incisions are made in the front of the knee to insert the arthroscope’s optical visualizing technology along with the surgical repair tools.

Securing the Work

Once placed, the graft is fixed into place using a series of small screws, staples and other miniature hardware. These parts are generally not removed after surgery — they stay in your body. Once everything has been put in place and locked down, the surgery is complete. The proof in the pudding comes when the surgeon is able to verify that the knee has its full range of motion and there’s enough tension in the graft.

When the procedure is completed, the surgeon closes the incisions and applies a sterile dressing. Some patients will have to wear a brace after the operation on a temporary, or more rarely, ongoing basis. As this procedure is on an outpatient basis, the patient will usually go home on the same day of the surgery.

What Happens After the Procedure?

The question that every surgery patient wants to know is how long until I’m better? This is especially true of athletes and sports enthusiasts who are eager to get back on the field or court. The time needed for successful rehabilitation is different for everyone. The rehab process actually starts on the day of surgery. Patients are given exercises to start right away.

The First Weeks After Surgery

The first two weeks after surgery will be focused on reducing the swelling in the knee. The goal is to see progress in knee extension rather than flexibility. The patient can help this process along by elevating/icing the leg and riding a stationary bike.

Will I Need Crutches?

Most ACL reconstruction patients use crutches after the procedure. It usually takes seven to 10 days after the surgery until the patient can walk comfortably and safely without the assistance of a crutch. If more knee work was done during the ACL reconstruction, the crutches may be necessary for a longer time.

Will I Be Able to Drive?

Most patients are off crutches and have adequate muscle function for safe driving in about two weeks’ time. Naturally, this is dependent on which leg has been operated on, how much work has been done and how fast the patient is able to recover.

How Is Rehabilitation Structured?

While different surgeons and physical therapists will prefer slightly different protocols, the goal for all forms of post-operative ACL rehabilitation is the same. The idea is to get the patient to a normal level of mobility function in as short a time possible while keeping the reconstructed knee safe.

In order to achieve this goal, physical therapy post-ACL reconstruction is usually broken down into timed phases. A conventional recovery protocol looks like this:

Phase I: Weeks 1-3

The emphasis:

  • Making sure swelling and inflammation are under control
  • Slowly re-acquiring progress toward normal knee motion
  • Working toward confident control of thigh function
  • Adherence to assigned rehabilitation tasks

Phase II: Weeks 4-6

The emphasis:

  • Gaining strength in the knee through exercise
  • Moving closer to full range of knee movement
  • Protecting the knee (and graft) from stress

Phase III: 6 Weeks to 3 Months

The emphasis:

  • Building confidence in full knee function
  • Building progress in knee strength and endurance
  • Some jogging and running after 3 months

Phase IV: 4 to 6 Months

Usually, by this time the patient can expect to return to full activity. Before being able to return to sports, several guidelines must be met:

  • No complaints about range of motion or a tender knee
  • Confidence in the knee’s strength and endurance
  • A thorough understanding of any limitations in the knee going forward

How Do I Get Started?

An ACL injury can cause lasting damage if not treated promptly. Guidance from an expert orthopedic surgeon ensures a thorough and accurate diagnosis, proper pre-operative preparation, the most appropriate surgical technique for each patient, and finally, the most effective post-surgical aftercare regimen.

If you’ve suffered a knee injury that may require correction, come see our experts. Contact Plymouth Bay Orthopedics in Plymouth, MA today to schedule an appointment.