Failed ACL Reconstruction

When the ACL is torn, it often requires surgical reconstruction to restore knee stability and allow patients to return to sports and daily activities. ACL reconstruction is one of the most common orthopedic surgeries, and for most patients, it provides excellent results. However, in some cases, the procedure does not achieve its intended outcome. This is referred to as a failed ACL reconstruction.

What is a failed ACL reconstruction?

ACL reconstruction is different from ACL repair. In reconstruction, the torn ligament is replaced with a tendon graft, either from the patient (autograft) or a donor (allograft). The graft is secured within bone tunnels to function as a new ligament. When this graft does not function as expected, it is considered a failed ACL reconstruction.

Failure can mean the graft has stretched or ruptured, that it was not properly positioned, or that it has not healed adequately. It may also refer to persistent instability, pain, or stiffness despite surgery. In some cases, failure is due to new trauma or re-injury. In others, it may result from surgical technique, graft choice, or biological healing factors.

What are the symptoms of failed ACL reconstruction?

The symptoms often resemble those of the original injury. Common signs include:

• A sensation of the knee giving way or buckling, particularly during twisting or pivoting activities
• Recurrent swelling, often after physical activity
• Ongoing pain in the knee joint
• Reduced range of motion or stiffness
• Difficulty returning to sports or physical activities

Some patients may also develop catching or locking of the joint due to damage to the meniscus or cartilage, which often occurs if instability persists. Over time, untreated graft failure can place additional strain on the knee and lead to long-term problems such as arthritis.

How is a failed ACL reconstruction diagnosed?

Evaluating a failed ACL reconstruction requires a comprehensive approach. The surgeon begins by reviewing the patient’s surgical history, including the graft type, fixation method, and rehabilitation course. Understanding whether the failure occurred early after surgery or later helps guide the next steps.

A physical examination is performed to test knee stability and range of motion. Special maneuvers such as the Lachman test and pivot shift test help assess whether the graft is intact and functioning.

Imaging studies are essential. X-rays can reveal the position of the bone tunnels, the integrity of fixation devices, and signs of arthritis. MRI scans provide a detailed view of the reconstructed ligament, cartilage, and meniscus. In complex cases, a CT scan may be ordered to evaluate tunnel placement and size before considering revision surgery.

Through this evaluation, Dr. Waterman determines whether the reconstruction has failed due to technical issues, biological reasons, or a new injury.

What are the risks and factors that contribute to a failure?

Several factors may contribute to failed ACL reconstruction:

• Technical issues: Incorrect tunnel placement is one of the most common causes of failure. If tunnels are too vertical or not aligned correctly, the graft cannot restore proper knee stability. Improper fixation or graft tensioning may also play a role.
• Graft choice: Allografts (donor tissue) may have higher re-tear rates in young, active patients compared to autografts. In some cases, the type of graft used may influence the durability of the reconstruction.
• Biological healing: The graft must heal and integrate into the bone tunnels. If this process is incomplete, the graft may loosen or fail.
• Re-injury: Returning to activity before full healing or sustaining another traumatic injury can damage the graft.
• Rehabilitation problems: Overly aggressive or insufficient rehabilitation can both negatively affect outcomes.

Long-term knee health is also a factor. Persistent instability can damage the meniscus and cartilage, creating additional challenges for revision surgery.

Identifying a failed ACL reconstruction early is essential to protect the knee from further damage. Ongoing instability not only limits a patient’s ability to return to sports but also increases the risk of secondary injuries. The longer instability persists, the greater the likelihood of developing meniscus tears, cartilage breakdown, and arthritis.

For young athletes, this can mean prolonged time away from sports. For active adults, it can result in chronic pain and reduced quality of life.

What are the treatment options for a failed ACL reconstruction?

When ACL reconstruction fails, the most common treatment is revision ACL surgery. Revision procedures are more complex than the original reconstruction. They often require correcting tunnel placement, choosing the right graft, and addressing additional injuries.

Revision ACL surgery may involve:

• New graft placement: A fresh graft, often from a different site than the original, is used to restore stability.
• Tunnel correction: Mispositioned or widened tunnels may require bone grafting and staged procedures before revision can be performed.
• Additional repairs: Meniscus or cartilage injuries that developed as a result of instability may need to be repaired at the same time.

Recovery from revision ACL surgery is generally longer and more challenging than recovery from the initial reconstruction. Rehabilitation must be carefully tailored to ensure proper healing and avoid re-injury.

In some cases, non-surgical management such as bracing, physical therapy, and activity modification may be considered. However, for young and active patients, surgery is usually necessary to restore stability and prevent further joint damage.

If you have had ACL reconstruction and continue to experience knee pain, instability, or swelling, it may be a sign of a failed reconstruction. Early evaluation is critical to protect your knee from further damage and to help you regain stability and function.

Dr. Brian Waterman, Board Certified and Fellowship Trained Orthopedic Surgeon and Sports Medicine Expert in Winston-Salem, North Carolina, specializes in diagnosing and treating complex knee conditions, including failed ACL reconstructions. With advanced training in revision surgery and a patient-centered approach, Dr. Waterman develops individualized treatment plans to restore knee stability and help patients return to the activities they enjoy.

Do not let persistent knee instability affect your quality of life. Contact Dr. Brian Waterman’s office today to schedule a consultation and explore your options for recovery.