Anterior Cruciate Ligament (ACL) Tear Symptoms and Treatment

How an ACL Tear Occurs

The anterior cruciate ligament (commonly referred to as the “ACL”) is one of the bands of tissue that holds the bones of your knee together.  One of the most common injuries to the knee is an ACL tear, where a sudden sharp turn, jolt, or forceful landing with the knee causes the ACL to tear, partially or completely.  The knee will often swell immediately if the ACL has been injured, and it can become immediately painful or difficult to walk or put pressure on the injured knee.

Anterior cruciate ligament ACL tear from a car accident
Photo by Mayo Clinic


What Are the Symptoms?

According to WebMD, many people hear a popping noise in their knee when they get hurt. But it doesn't happen to everyone. More common symptoms include:

  • Pain: If your ACL injury is minor, it is possible you will not feel much pain, you may not feel pain. You may feel sore along your knee's joint line. Some people have trouble standing or putting pressure on the hurt leg.
  • Swelling: This is most likely to happen during the first 24 hours. You can reduce swelling by putting ice on your knee and elevating (raising) your leg by propping it up on a pillow.
  • Difficulty Walking: If you're able to put pressure on your hurt leg, you may notice that it's harder than normal to walk. Some people find that the knee joint feels looser than it should.
  • Decreased Range of Motion. After you damage your ACL, it's very likely that you won't be able to bend and flex your knee like you normally would.

How Is It Diagnosed?

Your doctor will physically examine your knee, looking for swelling and tenderness in certain areas.  She will also likely compare your injured knee to your uninjured knee to look for differences in pain and range of motion and will move your knee through a  series of maneuvers to assess overall function of the joint.

Often the diagnosis can be made on the basis of the physical exam alone, but you may need x-rays, an MRI, or an ultrasound to rule out other causes, get a closer inspection of the ligaments, tendons, and muscles of the knee, and to determine the severity of the injury. 

How Is It Treated?

The Mayo Clinic recommends prompt first-aid care to reduce pain and swelling immediately after an injury to your knee. Following the the R.I.C.E. model of self-care at home (rest, ice, compression, and elevation).  This will also include limiting weight-bearing on your knee, intermittent icing, wrapping the knee for compression and stability, and propping your knee up while resting.  


Medical treatment for an ACL injury begins with several weeks of rehabilitative therapy. A physical therapist will teach you how to do exercises that you will perform either with continued supervision or at home. You may also wear a brace to stabilize your knee and use crutches for a while to avoid putting weight on your knee.

The goal of rehabilitation is to reduce pain and swelling, restore your knee's full range of motion, and strengthen muscles. This course of physical therapy may successfully treat an ACL injury for individuals who are relatively inactive, engage in moderate exercise and recreational activities, or play sports that put less stress on the knees.


Your doctor may recommend surgery if:

  • You are an athlete and want to continue in your sport, especially if the sport involves jumping, cutting or pivoting
  • More than one ligament or the cartilage in your knee is injured
  • You are young and active
  • The injury is causing your knee to buckle during everyday activities

During ACL reconstruction, the Mayo Clinic advises the surgeon removes the damaged ligament and replaces it with a segment of tendon — tissue similar to a ligament that connects muscle to bone. This replacement tissue is called a graft. Your surgeon will use a piece of tendon from another part of your knee or a tendon from a deceased donor. The graft will serve as scaffolding on which new ligament tissue can grow.

After surgery you will resume another course of rehabilitative therapy. Successful ACL reconstruction paired with rigorous rehabilitation can usually restore stability and function to your knee. You can learn more about ACL symptoms and treatment here.  If you believe you have suffered a knee injury from a car accident, it is likely the other driver's insurance company or your own insurance company may be responsible for your medical bills and treatment costs.  Bringing an experienced car accident attorneys in early to help guide you through the insurance claim process is the best way to ensure you protect your rights and take the right actions to recover as much as you are entitled to from the responsible insurance company. Contact us anytime for a free initial consultation.

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