Allograft ACL Reconstruction

Allograft reconstruction is a surgical technique to repair a torn anterior cruciate ligament (ACL) by substituting it with an allograft.

The femur (thigh bone), tibia (shin bone), and kneecap (patella) are the bones that connect at the knee joint. The joint is supported by four ligaments including anterior cruciate ligament, posterior cruciate ligament, lateral collateral ligament, and medial collateral ligament. A ligament is an elastic, connective tissue that helps in the functioning and supporting the joints. 

ACL is present in the middle of the knee behind the knee cap (patella). It helps in moving the tibia forward and controls its rotation. The ACL does not allow the shin bone to move ahead of the thigh bone and provides knee stability. The ligament may get torn when you suddenly twist the knee, causing the knee joint to become unstable. This is commonly seen in sports such as football, basketball, and skiing.

A surgery to fix the tear is needed if other non-surgical methods of treatment don't work. In this surgery, a healthy tendon from a donor (allograft) is used to replace the torn ligament.

The allograft may be obtained from the following tendons:

• Achilles tendon (the joining of the calf muscle to ankle bone)
• Hamstring tendon (tendon at the back of the thigh)
• Patellar tendon (the tendon below the knee between the knee cap and the tibia)
• Quadriceps tendon (the tendon between the thigh and the patella)

Allograft ACL reconstruction may be required to repair a torn ACL ligament in the following conditions:

• Your knee is not stable after a complete rehabilitation programme.
• Your job or sport requires knee stability and strength.
• The ACL damage is affecting your quality of life.

You will be eligible for allograft reconstruction if:

• Your age is more than 40 years
• This is a subsequent ACL reconstruction
• More than one knee ligament is damaged
• You have a personal preference

The symptoms of a torn ACL include:

• You will not feel like your knee is stable
• A feeling of the knee giving away while using
• A popping sound when your ligament ruptures or moves out of place
• Swelling and pain
• The injured knee cannot bear the weight of the leg
• A feeling of grinding bones against one another at the knee

The surgery may not be done in the following conditions:

• You have a minor tear that can heal with rest.
• If you can undergo a rehabilitation programme that helps in strengthening your knee and muscles, and if you are okay with minor instability in your knee.
• You live a sedentary lifestyle.
• If you choose to make changes to your lifestyle to incorporate activities that do not need complete knee stability such as swimming or cycling.
• Medical problems that can increase the risk during the surgery.

Some of the following preparations are needed before this surgery: 

• Your surgeon will ask you to share the following details:
  • Medical history
  • A list of medicines that you take
  • If you consume more than one to two drinks a day
  • Pregnancy status
• A physical examination will be conducted, and you will need to undergo a few tests including::
  • Magnetic resonance imaging (MRI)
  • Computed tomography (CT) scan
  • Bone scan (a diagnostic technique to determine disorders in the bone)
  • Arthroscopy (a technique used to look into the joint)
  • X-ray
  • Blood tests
• You may need to stop taking certain medications such as aspirin, naproxen, and ibuprofen before the surgery. 
• You will have to stop smoking if you are a regular smoker. 
• You may need to stay on an empty stomach (no food or water) for at least six to 12 hours before the surgery.
• You will have to sign an approval form if you agree to the procedure. 
• Arrange for a friend, family member, or responsible adult to drive you home following the surgery.

On arriving at the hospital, you will be asked to put on a hospital gown. An intravenous (IV) line will be inserted in your arm to provide you with essential fluids and medicines during the surgery. You will be asked to lie on the operating table. The surgery will be performed under general (you will be asleep for the surgery) or regional anaesthesia (numbs the area of operation, but you will be awake). Throughout the procedure, your doctor will constantly keep a check on your vital signs. The procedure may be performed by an arthroscopic or open technique.

Arthroscopic procedure involves the following steps:

• The surgeon will clean the site of operation using an antiseptic solution and make two or three small cuts (incisions) on your knee.
• Through one of the incisions, he/she will insert a saline solution into your knee to inflate the joint and wash away any blood from the region for better viewing. 
• The surgeon will insert an arthroscope (a device with a camera attached at one end) into your knee and view the insides of the joint on a screen and determine the extent of damage due to injury (diagnostic arthroscopy). 
• Through the other cuts, he/she will insert special instruments and drill small holes on your thigh and shin bone. 
• Through these holes, the surgeon will secure the allograft into place. He/she may use staples or screws to fix the graft. 
• Finally, the surgeon will close the incisions on your skin using staples or stitches and cover the area with a surgical dressing.

Open surgery is carried out in the same way but with a single, large cut on the knee.

The procedure lasts for about two to two and a half hours. Once the surgery is complete, the hospital staff will shift you to the recovery room and monitor your vitals. Once you are alert and stable, you will be discharged and will leave the hospital with crutches and a knee brace.

Once at home after the surgery, you will need to take care of yourself in the following manner:

• Your doctor will prescribe pain medicines that should be taken as directed. 
• You will have swelling in your knee for a few days. This can be reduced by applying ice for at least a few times in a day and keeping the leg in an elevated position.
• You will need the help of crutches while walking initially to prevent putting weight on your knee.
• The dressing can be removed after 48 hours and a band-aid or gauze can be applied in its place. However, make sure to replace them every day and do not coat the surgical site with any lotion or ointment.
• You may be allowed to shower five days after the surgery. Keep the incision wrapped in a plastic wrap, and do not let it get wet till the stitches are removed. 
• The knee brace will be required for at least six weeks. 
• Avoid standing, sitting, or walking for too long for the first week or two to reduce the pain and swelling. For two weeks, your doctor will suggest you to do gentle exercises that you can easily perform at home. Daily activities can be started 15 to 20 days after the surgery. 
• You will need physical therapy after about 14 days. This will continue for at least six months and performed once or twice a week. After about four months, you will be able to run, and at the end of six months, you will be able to change directions while running. 
• You may be able to resume work two to three weeks after the surgery, but make sure to wear the leg brace unless your surgeon suggests otherwise. 
• Your doctor will ask you to avoid driving as long as you are taking narcotic pain medication. However, it may take a while to resume driving and be able to hit the brakes in an emergency effectively.

Allograft reconstruction helps to restore the normal movement and stability of the knee. Due to the elimination of the instability in the knee, there are chances that arthritis (swelling of one or more joints) may be delayed. Pain and stiffness also decrease following the procedure.

When to see the doctor?

See the doctor immediately if you observe the following symptoms:

• Fever
• If your incision opens
• Redness or drainage from the incision site 
• Increased pain in the knee
• Tingling, numbness, or loss of functioning in the knee
• Nausea 
• Pain and swelling of the calf

The surgery carries the following risks:

• Infection
• Pain in the knee while kneeling and doing any activity
• Graft failure or rupture
• Damage to the tissue around the knee
• Less range of motion compared to the other leg
• Blood clots in the leg 
• Scar tissue formation 
• Risks due to anaesthesia

Your first follow-up will be seven to 14 days after the surgery wherein the doctor will check the wound and remove your stitches. Another follow-up will take place about six weeks later.

Disclaimer: The above information is provided purely from an educational point of view and is in no way a substitute for medical advice by a qualified doctor.