A torn anterior cruciate ligament (ACL) can make your knee feel unsteady when you pivot, land from a jump, or change direction. If that instability interferes with your work or a sport you enjoy, an LBJI orthopedic surgeon can help you determine whether ACL reconstruction is right for you.
At Lakeshore Bone & Joint Institute (LBJI), we start by asking which movements feel difficult and what you’d like to get back to doing. If you’re considering reconstruction, we’ll talk through your graft options and what each could mean for your recovery.
How ACL Reconstruction Helps Stabilize Your Knee
The ACL connects your thighbone (femur) to your shinbone (tibia). It helps steady your knee when you turn on a planted foot and keeps your shinbone from sliding too far forward. After a tear, some people regain enough stability with physical therapy, while others continue to feel their knee buckle, especially during activities that involve quick turns or sudden stops.
During ACL reconstruction, your LBJI knee specialist replaces the torn ligament with a piece of tissue called a graft. As the graft heals, it takes on the ACL’s role in keeping your knee stable.
Where Does an ACL Graft Come From?
One of the first decisions you and your physician will discuss is where the graft tissue will come from. An autograft uses your own tissue, while an allograft uses donor tissue.
Your Own Tissue (Autograft)
An autograft uses a portion of a healthy tendon taken from your leg during the same operation. This means two areas need to heal: the reconstructed ligament inside your knee and the area where the tendon was taken. Which tendon is used can influence where you feel soreness and which muscles need extra attention during rehabilitation.
An autograft is often recommended for younger patients and athletes who plan to return to sports that involve cutting or pivoting. In these groups, a graft made from the patient’s own tissue is generally more likely to provide lasting knee stability than one made from donor tissue.
Donor Tissue (Allograft)
An allograft uses donor tissue that is screened and processed before surgery. Depending on the graft, it may consist of tendon alone or include small pieces of bone at the ends.
Using donor tissue avoids the soreness or weakness that can occur where a tendon is taken from your leg. If your activities put less demand on your knee, an allograft may be a better option. It can also be considered when a previous surgery has limited the available tendon tissue, or several ligaments need reconstruction. The graft still needs time to heal, even if your leg feels comfortable early in recovery.
Comparing Three Tendon Graft Options
Patellar Tendon: Below Your Kneecap
The patellar tendon connects the bottom of your kneecap to your shinbone. A bone-patellar tendon-bone graft, often called a BPTB graft, uses a strip of this tendon with a small piece of bone at each end. The bone ends fit into tunnels in your thighbone and shinbone, where they can heal to the surrounding bone. This type of graft can come from your own knee or from a donor.
A patellar tendon autograft is often considered for athletes returning to sports such as soccer, basketball, football, or skiing. Some people experience discomfort at the front of the knee, especially when kneeling. If your job requires frequent kneeling, discuss this with your surgeon when choosing a graft.
Hamstring Tendons: At the Back of Your Thigh
A hamstring graft uses one or more tendons from the muscles at the back of the thigh. Whether the tissue comes from your own leg or from a donor, it is typically folded it to create a graft of the desired thickness.
A hamstring autograft leaves your patellar tendon intact and generally causes less pain with kneeling than a patellar tendon autograft. Your hamstrings help bend your knee, so you may notice weakness with that movement as the area heals. Your surgeon will consider the size of the available tendon and how much hamstring strength your sport or work requires.
Quadriceps Tendon: Above Your Kneecap
The quadriceps tendon connects the muscles at the front of your thigh to the top of your kneecap. The graft uses a strip of this tendon, either on its own or with a small piece of bone from your kneecap.
A quadriceps tendon autograft preserves your hamstring tendons and may be considered for a first reconstruction or after a previous ACL surgery. Because your quadriceps help straighten your knee and control movements such as stepping down a stair, rebuilding strength in the front of your thigh is an important part of recovery.
Choosing a Graft That Fits Your Activities
Your LBJI physician will review your examination and imaging with you, then discuss how each option fits the demands you place on your knee. Factors that can influence the recommendation include:
- Your age and activity level. Returning to a sport with quick turns and sudden stops places different demands on your knee than walking or cycling. Work duties such as kneeling, climbing ladders, and carrying heavy loads also matter.
- Symptoms where the graft is collected. With an autograft, the location of soreness or weakness depends in part on which tendon is used. Let your surgeon know if you already have pain in the front of your knee or difficulty with certain movements.
- Other injuries in your knee. A torn ACL can occur along with a meniscus tear, cartilage damage, or an injury to another ligament. These findings may affect the surgical plan and what you can do in the early stages of recovery.
- Previous knee surgery. If you have had an ACL reconstruction before, the tendon used and the location of the original graft can influence your options for a second reconstruction.
- Surgical technique and experience. Grafts with bone at the ends and grafts made entirely of soft tissue can be secured in different ways. Your surgeon can explain which approach they recommend for your knee and why.
What to Expect During ACL Recovery
The type of graft can affect which movements feel uncomfortable at first and where you need to rebuild strength. For example, kneeling may be uncomfortable after a patellar tendon autograft, while bending your knee against resistance may be more difficult after a hamstring autograft. Across graft types, recovery also depends on:
- Whether your surgeon treated another injury during the procedure
- How well swelling settles and knee motion returns
- Your progress with strength, balance, and knee control during physical therapy
- The demands of the job, activity, or sport you plan to resume
Early rehabilitation focuses on restoring motion and helping you walk comfortably. As you progress, your physical therapist gradually introduces more exercises that more closely match your goals. Before you return to a pivoting sport, for example, your care team may assess how you land on one leg or change direction, alongside your strength, symptoms, and the time the graft has had to heal.
Frequently Asked Questions About ACL Reconstruction
Why might I start physical therapy before ACL reconstruction?
After an ACL tear, swelling can make it difficult to fully bend or straighten your knee. Your care team may recommend physical therapy before surgery to help reduce swelling and restore motion as you prepare for reconstruction.
How could a meniscus repair change my ACL recovery?
If you tear both your ACL and your meniscus, your surgeon may be able to repair the meniscus during ACL reconstruction. While it heals, you may need to limit how much weight you put on your leg or how far you bend your knee. Your care team will explain what that means for walking and physical therapy in the first few weeks.
What can I do to lower the risk of another ACL injury?
As you prepare to return to sports, your physical therapist can help you practice movements that place extra demands on your knee, such as landing from a jump, slowing down, and changing direction. Following your rehab plan gives you time to build strength and practice those skills before you use them in a game.
Discuss Your ACL Options at LBJI
If your knee gives way after an injury or keeps you from the activities you enjoy, our knee and sports medicine specialists can help you understand your options. If reconstruction is recommended, we’ll discuss which graft fits your injury, what to expect during rehabilitation, and how your plan can support a return to work or sports.
Schedule an appointment with Lakeshore Bone & Joint Institute to discuss ACL treatment and graft choices in Northwest Indiana.