M.D. Insights


ACL Repair, Reconstruction, and Recovery


Matthew Zapf, MD

Orthopedic Surgery - Sports Medicine

Anterior Cruciate Ligament

Engaging in exercise or sports is one way to keep your body healthy and enjoy life. Sometimes external factors, accidents or just pushing beyond your limits may result in an anterior cruciate ligament (ACL) injury.

Imagine a soccer player sprinting down the field, attempting to change direction and pivot quickly. In that split second, they plant their foot firmly and twist their knee. However, their body is still moving, applying more stress to their knee than usual. The next thing they know, they hear a popping sound and feel the onset of pain – both symptoms of a torn ACL.

Understanding ACL Injuries 

The ACL connects your shin bone (tibia) to your thigh bone (femur). It’s one of the cruciate ligaments that stabilizes the knee by limiting its rotational motions and preventing the tibia’s excessive forward movements. ACL injuries happen when the ligament becomes stretched or torn because of some stress placed on the knee. An ACL tear can cause the knee to lose balance during physical activity, especially with crossover or side-step movements. ACL injuries may result from:

  • Direct contact of external force to the injured knee.
  • Indirect contact of external force to other body regions other than the injured knee.
  • Non-contact wherein the knee gets injured without colliding with other people or external objects. This injury may result from jump-landing movements or movements that involve sudden change of direction and deceleration.

When you injure your ACL, you may hear a popping sound and feel your knee buckle, just like the soccer player earlier. Other ACL injury symptoms may include:

  • Knee swelling within 6 hours of injury
  • Knee pain when putting your weight on the injured leg
  • Restricted range of motion
  • Discomfort while walking
  • Knee feels unstable

An orthopaedist can diagnose an ACL tear through a physical examination. Your doctor will ask about symptoms and history during your consultation. They will then examine your knee and may compare it to the non-injured knee. Your doctor may order X-rays or magnetic resonance imaging (MRI) scans to confirm the diagnosis and check whether there’s another injury to other knee soft tissue.

ACL Repair vs. ACL Reconstruction

Currently, evidence supports ACL repair for specific injuries to the ACL where it is torn directly off the bone insertion. If it is torn in the middle of the ligament, reconstruction is the supported treatment.

  • ACL repair – the torn ACL is reattached.
  • ACL reconstruction – a graft taken from the patient’s body or a tissue bank will be used to replace the damaged ligament.

ACL repair means the ligament will be reattached to its insertion on the femur (thigh bone) or tibia (shin bone) with specific devices and allow it to heal. Reconstruction, on the other hand, will require using a graft. The surgeon will review the graft options with you and is based on several factors.

The decision to undergo surgery may depend on the patient’s baseline physical activity level, age, functional demands, overall health, occupation and other existing injuries. Athletes or highly physically active individuals may be more inclined to choose surgery to get them back to their usual physical activities as soon as possible. On the other hand, patients may decide not to undergo surgery if they don’t have a very active lifestyle or participate in sports that require a lot of pivoting or cutting maneuvers. These patients may be able to function normally even without surgery.

ACL Injury Treatment

In general, ACL injury treatment is guided by your level of activity and desire to return to sports or an active lifestyle. Other factors, such as presence of osteoarthritis or general health, will also play a role. Treatment goals include:

  • Restore knee stability and reduce pain
  • Improve knee range of motion
  • Prevent other knee problems from occurring

Your doctor will recommend appropriate treatment options after thoroughly examining your knee, the extent of its damage and other medical factors. Each treatment option has different benefits and risks, so ask your surgeon as much information as possible to help prepare you better.

Most patients wishing to return to sports or higher demand activities may opt for surgery. On the other hand, nonsurgical management of ACL injury may be enough for patients with less active lifestyle.

ACL Surgery Recovery

Patients can go home within the day of the surgery. Your doctor may recommend wearing a knee brace and using crutches after surgery, the duration will depend on any additional procedures done during the surgery. Typically, no longer than 6 weeks if a meniscus repair was performed, 8 weeks if cartilage surgery or as short as 2 weeks if just the ACL was reconstructed. Physical therapy may last up to 12 months. While it is important to stick to the physical therapy routine, tell your therapist if you feel pain or something feels wrong. Physical therapy is not a “no pain, no gain” approach. Pushing yourself too much through pain can do more damage and delay your recovery.

How soon you can go back to your usual physical activity will depend on the kind of movements your activity requires. In general, rehabilitation from an ACL repair or reconstruction may take up to 12 months. This may be longer if you do not consistently perform the prescribed exercises that will build the strength necessary to safely return to sport or activity. This is also a progressive process, so you will be active throughout and not just doing exercises. For example, at 4- 6 months after surgery we want our patients working through increasingly demanding sport-specific motions and form. From there, we work to optimize your strength and safeguard your knee.

Safeguarding Your Knees from ACL Injury

Your knees support you in every step, so optimizing how you control your trunk during activities, proper form during workouts and sport and improving techniques all go a long way to prevent future injury or re-injury. Consult a doctor if you notice any symptoms such as pain that does not resolve, swelling or sensations of knee instability for appropriate diagnosis and treatment.