ACL Surgery: What to Expect on the Day of Surgery

ACL surgery involves reconstructing an injured anterior cruciate ligament using a tendon graft that comes from either a deceased donor or the patient themself. The surgery is performed arthroscopically (with small incisions) by an orthopedic surgeon under general anesthesia in a hospital or surgical center.

Surgeon about to make a knee incision
ViktorCap / Getty Images

Before the Surgery

On the day of your surgery, you will arrive at the hospital or surgical center and check in, which will involve signing a surgery consent form. After that, you will go to a pre-operative room.

Here, you can expect the following:

  • You will change into a hospital gown.
  • A nurse will record your vitals (temperature, blood pressure, etc.) and place an intravenous (IV) line into a vein in your arm for administering fluids and medications.
  • Your orthopedic surgeon and anesthesiologist will come to say hello and briefly review the surgery with you.

When the surgical team is ready, you will be taken into the operating room where you will lie on an operating table. You will then be given anesthesia medication to put you to sleep.

During the Surgery

Once you are asleep, the anesthesiologist will insert a breathing tube, which is connected to a ventilator. During the entire surgery, which will last less than two hours, the anesthesiologist will remain in the operating room to adjust your anesthesia medications and monitor your vitals.

Your ACL surgery will typically proceed with the following steps:

Confirming the ACL Tear Diagnosis

In order to visualize and confirm the diagnosis of an ACL tear, your surgeon will make two to three small incisions (cuts) around the knee and insert an arthroscope into the knee joint to inspect the ligament injury. In addition to the ACL, the knee meniscus, cartilage, and other ligaments may be inspected for damage as well.

It is not uncommon for meniscus tears and cartilage injuries to be surgically treated at the same time your ACL is being repaired.

Harvest and Prepare the ACL Graft

Once the ACL tear is confirmed, a graft must be obtained—a process called harvesting. There are a few ACL graft options that may be considered.

Autografts, those taken from elsewhere in your own body, can be harvested from:

  • The patellar tendon
  • The hamstring tendon
  • Quadriceps tendon (less common)

An incision is made to obtain the tissue.

An allograft (a tendon from a deceased donor) is another option that is commonly used. The donation must be thawed before it is used in surgery, but this type of graft prevents you from having an additional incision just to harvest tissue.

After obtaining the graft, the tissue being used to create a new ACL is cleaned and trimmed to the proper length and width. The graft is then set aside and put in a special tissue storage unit until the knee is ready for the new ACL.

Creating a Tibial (Shin) Tunnel

The next step is to create a place for the new ACL to sit within the knee. The ACL is right in the center of the knee joint and needs to be attached to the bone above and below the joint. Therefore, the new ligament must start within the end of the thigh bone and end within the top of the shin bone.

A drill is used to make a tunnel in the shin bone. The end of this tunnel in the knee joint is directly where the ACL should attach to the shin bone.

Creating a Femoral (Thigh) Tunnel

Through the tibial tunnel just created, a drill is passed directly through the middle of the knee joint. A second bone tunnel is made from inside the knee up into the end of the femur.

This bone tunnel will hold one end of the new ACL, and the tibial tunnel will hold the other.

Passing the Graft

A large pin with the graft attached to its end is passed through both bone tunnels.

The new ACL is pulled up into the femoral tunnel so one end can be secured to the femur. The other end is now in the tibial tunnel; its central portion is in the middle of the knee joint, taking the place of the old ACL.

Securing the Femoral Side of the Graft

With the ACL graft in position, the graft must be solidly fixed in its new home.

One common way to do this is to use a screw to hold the graft end within the tunnel. The screw can be made of metal, a plastic-dissolvable material, or a calcium-based substance that turns into bone.

Your healthcare provider may recommend a particular type of material, although none has been shown to be better at securing the graft than another.

Securing the Tibial Side of the Graft

Once the graft is solidly fixed on the femoral side, tension is placed on the end of the graft so the new ACL will be tight. The tibial side of the new ligament is then fixed, similarly to the femoral side. Again, different materials may be used to fix the graft into position.

Over time, the graft will heal to the surrounding bone, making the fixation devices unnecessary. Occasionally, a prominent screw or staple that was used to hold the graft in position may be removed after about a year. If not causing problems, these materials are usually left in place.

Closing the Incision Sites

After the graft is secured, the surgeon will close the incision sites with stitches or tape strips. A bandage will be placed over the knee.

Anesthesia medication will be stopped, the breathing tube will be removed, and you will be taken to a recovery room where you will wake up.

After the Surgery

After ACL surgery, you can expect to be in the recovery room for about two to three hours. During this time, a nurse will do the following:

  • Monitor your vital signs
  • Ask you about pain—often using a standard pain scale of 0 (no pain) to 10 (the worse pain ever)—and give you medication, as needed

If your vitals are stable and your pain is under control, you will be discharged. A friend or family member will need to drive you home.

Upon discharge, your surgeon will give you various post-operative instructions.

Some of these instructions may include:

  • Applying ice and elevating your knee regularly to reduce swelling
  • Taking pain medication, usually an opioid and nonsteroidal anti-inflammatory drug (NSAID), for short-term pain relief
  • Performing various knee exercises and moving around with crutches
  • Keeping the incision site dry until the stitches are removed
  • Following-up with your surgeon (within a few days) to remove stitches and monitor for complications (e.g., infection or knee stiffness/loss of motion)
  • Attending physical therapy appointments, which will begin immediately after surgery

A Word From Verywell

ACL surgery can restore knee function and range of motion, but the ultimate success of your procedure does require work on your part. During your recovery and healing process, be sure to follow up with your surgeon as advised and remain steadfast and committed to your knee rehabilitation program.

11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. American Academy of Orthopaedic Surgeons. Knee arthroscopy.

  3. Feucht MJ, Bigdon S, Bode G, et al. Associated tears of the lateral meniscus in anterior cruciate ligament injuries: risk factors for different tear patterns. J Orthop Surg Res. 2015;10:34. doi:10.1186/s13018-015-0184-x

  4. Widner M, Dunleavy M, Lynch S. Outcomes following ACL reconstruction based on graft type: are all grafts equivalent? Curr Rev Musculoskelet Med. 2019;12(4):460-465. doi:10.1007/s12178-019-09588-w

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  8. Debieux P, Franciozi CE, Lenza M, et al. Bioabsorbable versus metallic interference screws for graft fixation in anterior cruciate ligament reconstruction. Cochrane Database Syst Rev. 2016;7:CD009772. doi:10.1002/14651858.CD009772.pub2

  9. Almeida A, Roveda G, Valin MR, Almeida NC, Sartor V, Alves SM. Complications of the screw/washer tibial fixation technique for knee ligament reconstruction. Rev Bras Ortop. 2010;45(5):409-414. doi:10.1016/S2255-4971(15)30428-6

  10. University of Michigan. Anterior Cruciate Ligament (ACL) Surgery.

  11. American Academy of Orthopedic Surgeons. ACL Injury: Does It Require Surgery?

Additional Reading

By Jonathan Cluett, MD
Jonathan Cluett, MD, is board-certified in orthopedic surgery. He served as assistant team physician to Chivas USA (Major League Soccer) and the United States men's and women's national soccer teams.