Revision ACL Reconstruction Surgery
Revision ACL reconstruction is a second surgery to reconstruct the anterior cruciate ligament when a previous ACL reconstruction has failed — whether because the graft stretched or ruptured, the original tunnel placement was suboptimal, the graft did not incorporate fully into the bone, or a new traumatic injury damaged the reconstructed ligament. ACL graft failure occurs in approximately 5 to 10 percent of primary reconstructions, and when it does, patients typically experience a return of the instability, giving way, and loss of confidence in the knee that led to the original surgery. Revision ACL surgery is significantly more complex than a primary reconstruction — the surgeon must work within the altered anatomy of a previously operated knee, address widened or malpositioned bone tunnels from the first surgery, select the right graft source when the primary graft has already been used, and in some cases stage the procedure over two operations to rebuild bone stock before placing the new graft.
Dr. Jonathan Glashow is a board-certified orthopedic surgeon and Clinical Associate Professor of Orthopedic Surgery at NYU Grossman School of Medicine, widely recognized as one of New York City’s foremost ACL surgeons — and it is precisely this depth of ACL experience that makes him a trusted choice for revision cases, which represent the most technically demanding subset of ACL surgery. A pioneer of the all-inside ACL reconstruction technique, published researcher in the Journal of Bone and Joint Surgery on ACL and meniscal diagnosis, and one of the first surgeons to perform the BEAR implant procedure commercially, Dr. Glashow has spent over 30 years refining the full spectrum of ACL reconstruction approaches — knowledge that is essential for diagnosing why a primary reconstruction failed and designing a revision strategy that addresses the specific cause of failure. As Chief Medical Officer for the New Jersey Devils and Philadelphia 76ers, he manages ACL re-injuries in professional athletes where the stakes of revision surgery are the highest. With more than 15,000 procedures performed and recognition as a Castle Connolly Top Doctor every year since 2000, he performs revision ACL reconstruction at his Upper East Side practice in New York City.
Why ACL Grafts Fail and How Revision Differs
A primary ACL reconstruction can fail for several reasons, and identifying the specific cause of failure is the most important step in planning a successful revision. The most common causes include traumatic re-injury to the reconstructed graft during a return to sports, suboptimal tunnel placement during the original surgery that positioned the graft outside its anatomic attachment point, inadequate graft incorporation where the graft did not fully heal into the bone tunnels, graft stretching over time that produced progressive laxity without a single re-injury event, and unaddressed contributing factors such as limb malalignment or unrecognized meniscus or ligament injuries that placed excessive stress on the reconstructed ACL.
Revision surgery differs from primary reconstruction in several important ways. The bone tunnels drilled during the first surgery may have widened or may be in the wrong position — requiring bone grafting to fill the old tunnels before new ones can be placed, sometimes as a separate staged procedure. The graft source used in the primary surgery (typically patellar tendon or hamstring) may no longer be available, requiring the use of allograft (donor tissue) or an alternative autograft site. Any associated injuries — meniscus tears, cartilage damage, alignment issues — that may have contributed to the original graft failure must be addressed simultaneously. Dr. Glashow performs a comprehensive evaluation including CT imaging of the existing tunnels, MRI assessment of graft integrity and associated injuries, and clinical examination of alignment and ligamentous stability before developing a revision surgical plan.
If your previous ACL reconstruction has failed and you are experiencing renewed instability, giving way, or loss of confidence in your knee, revision ACL surgery can restore the stability you need to return to the activities that matter to you. Dr. Glashow offers comprehensive revision evaluation — including CT tunnel assessment, MRI, and clinical examination — at his Upper East Side practice in New York City. Contact our office to schedule your consultation.
Frequently Asked Questions About Revision ACL Reconstruction
How do I know if my ACL graft has failed?
The most common signs of ACL graft failure are a return of knee instability — episodes of the knee giving way during pivoting, cutting, or deceleration — along with swelling after activity, a loss of confidence in the knee during sports, and in some cases a new pop followed by pain and swelling similar to the original ACL injury. Some graft failures are traumatic (a clear re-injury event), while others are gradual (progressive stretching of the graft over time). Dr. Glashow evaluates suspected graft failures with clinical examination, MRI, and in many cases CT imaging to assess tunnel position and bone stock.
Is revision ACL surgery more difficult than the original reconstruction?
Yes. Revision ACL reconstruction is significantly more complex than a primary procedure. The surgeon is working within altered anatomy — existing tunnels, scar tissue, potentially compromised bone stock, and previously harvested graft tissue. Each revision must be planned individually based on why the first reconstruction failed, what graft and tunnel positions were used, and what associated injuries need to be addressed. The surgical experience required for revision ACL work is substantially greater than for primary reconstruction, which is why many patients seek out a high-volume ACL specialist for their revision procedure.
What graft is used for revision ACL surgery?
The graft choice depends on what was used in the primary reconstruction and the condition of the remaining tissue. If the original surgery used a patellar tendon autograft, Dr. Glashow may use a hamstring autograft, a quadriceps tendon autograft, or an allograft (donor tissue) for the revision. Allograft is used frequently in revision cases because it avoids the need to harvest additional tissue from the patient’s already-operated knee. Dr. Glashow discusses graft options with each patient individually, considering factors including tunnel position, bone stock, patient age, activity level, and the demands of their sport or occupation.
Will I need a two-stage revision?
Some revision ACL reconstructions can be performed in a single surgery. However, when the existing bone tunnels are significantly widened or malpositioned — which occurs when the tunnels from the first surgery were too large or placed outside the anatomic footprint — a staged approach may be necessary. In the first stage, the widened tunnels are filled with bone graft and allowed to heal for several months. In the second stage, new tunnels are drilled in the correct anatomic position and the revision graft is placed. Dr. Glashow uses CT imaging to evaluate the existing tunnels and determine whether a single-stage or two-stage approach is most appropriate.
How long does recovery take after revision ACL reconstruction?
Recovery from revision ACL surgery generally takes longer than primary reconstruction — typically nine to twelve months before a return to full sports, compared to six to nine months for a primary ACL. The rehabilitation is more conservative in the early phases to protect the graft and any associated procedures (such as meniscus repair, cartilage restoration, or bone grafting). Dr. Glashow coordinates rehabilitation closely with physical therapists and uses objective criteria — not just a calendar timeline — to determine when each patient is ready to progress through each phase and ultimately return to activity.
What is the success rate of revision ACL surgery?
Revision ACL reconstruction has a good success rate when performed by an experienced surgeon with proper preoperative planning — published studies report satisfactory stability in approximately 75 to 85 percent of revision cases. However, outcomes are generally somewhat lower than primary ACL reconstruction (which has success rates above 90 percent), because the revision is performed in a more challenging surgical environment with altered anatomy and often associated cartilage or meniscus damage. The single most important factor in revision success is accurately identifying and correcting the cause of the original graft failure.
