ACL Tear - Anterior Cruciate Ligament Tear in the Knee

What is an ACL tear?: An ACL tear is a serious injury to the knee. It is one of four major ligaments in the knee. It runs diagonally down the middle of the knee and prevents the upper and lower leg from sliding over each other (keeping the lower leg from sliding out from the femur). It also provides rotational stability to the knee.

Causes: Can an ACL tear be caused in a car accident? Yes. Definitely. ACL tears are caused by suddenly severely twisting the leg/knee, or hyper-extending the leg upon impact in the auto accident. The most common injury to the knee in a car accident is a sprain, strain, or torn ACL.

Sports injuries, trauma, automobile collisions, falls, hard landings, sudden change of direction, stiff legged landings, knee rotating on landing, if you plant your foot into the ground really hard while cutting to another direction, landing flat on your heels, all can cause injury to the ACL.

Symptoms: Right away people usually feel a sharp pain in the knee and often a "popping" sensation. The knee will swell up, and feel unstable. Usually, within hours there is a large amount of swelling and some loss of range of motion. There is pain on the joint while walking.


Nonsurgical: Physical therapy and rehabilitation can be done and almost restore full function to the knee in many cases. The problem with this is that there are typically episodes of instability in the knee and those periods of instability can lead to further knee damage.

Surgical: Grafts are used to replace and create a new ACL in the knee. Different grafts include:

  1. Patellar tendon autograft (autograft comes from the patient): The surgeon cuts out a part of the tendon just below the kneecap (patellar tendon), and uses that tendon to surgically replace the torn ACL.
  2. Hamstring tendon autograft: The surgeon takes part of the patients hamstring (on back of leg) close to the knee and uses that to create a new ACL.
  3. Quadriceps tendon autograft: Here the surgeon takes part of the tendon above the kneecap (closer to the quadraceps - front leg muscle close to the knee). This is usually done where there was a prior ACL reconstruction failure. Its a larger graft for tall and heavy patients.
  4. Allograft (taken from a cadaver): patellar tendon, Achilles tendon, semitendinosus, gracilis, or posterior tibialis tendon. Allografts are taken from a dead person (cadaver). The advantage is that the surgery is less painful (since you aren't cutting in two different parts of the body to repair itself). The surgery is also faster. Disadvantages of allografts include - risks of infection of viral transmissions including HIV, Hepatitis C. This happens sometimes despite careful screening. Bacterial infections can cause death due to improper procurement and sterilization. Failure rates are 23%-34%, compared to only a 5%-10% failure rate in "autografts" (where you take the material from your own body to create a new ACL).

Rehabilitation After ACL Surgery: Usually takes about 4-6 months.


If you have a torn ACL, or suspect you may have one due to a car accident, you need to contact a personal injury attorney to protect your rights regarding your injury, the cost of treating your injury, and other financial consequences of such a serious injury.

Call us at (972) 599 4100 to discuss your case to determine if you need a personal injury attorney, or if you should continue to handle the case without an attorney. We will discuss all the factors you need to consider in making your decision.