What Are Knee Ligament Tears?

The knee joint is made of three main bones – the thigh bone (femur), shinbone (tibia) and kneecap (patella) – and four primary ligaments, all of which can get stretched or even tear. So, what exactly is a knee ligament tear and how can it be repaired?

A ligament is a cord-like band that connects two bones around a joint. It’s made up of tough, elastic connective tissue, and it helps to stabilize and support the knee in moving, bending and extension during everyday activities like walking, swimming and sporting activities. From the moment a knee ligament tears, you may experience anything from minor pain to chronic long-term injury, impacting your ability to enjoy work, play and overall quality of life.

The knee joint is made up of four ligaments, each with their own particular function and characteristics:

  • The medial collateral ligament (MCL) sits on the inner part of the knee. It runs from the outer knee joint and joins the thigh bone and the shin bone, on the inside of the knee. It shields the knee from any blows coming toward the outer side of the knee, secures the inner knee, and prohibits the joint from moving too much from side-to-side.
  • The lateral collateral ligament (LCL) stretches from the thigh bone to the fibula on the outer surface of the knee joint. It secures the outer knee, and limits hazardous sideways movement.
  • The anterior cruciate ligament (ACL) is the most often injured knee ligament. It’s particularly susceptible to sudden twisting movements, typically associated with sports like basketball, hockey and football. The ACL moves across the heart of the knee, connecting the front of the tibia to the back of the thigh bone. The ACL manages rotation and flexion of the knee and stabilizes the shin bone.
  • The posterior cruciate ligament (PCL) is situated on the inner knee joint and directs backward motion of the tibia. The PCL runs diagonally across the knee where it intersects the ACL and joins the back of the shin bone to the front of the thigh bone.

What Are the Signs and Symptoms of Knee Ligament Tears?

Knee Ligament TearsThe symptoms one experiences the moment a knee ligament is torn will generally be similar, irrespective of which ligament was damaged. The gravity of the injury usually determines the severity of symptoms. Individuals might suffer increased, intense symptoms from a fully torn ligament, and fewer, less harsh symptoms from a stretched or strained ligament.

The instant the ligament is injured, patients may hear a popping noise in the knee, accompanied by immediate and extreme pain. Bleeding in the knee may cause it to swell up; and a tender and bruised knee with diminished mobility is not uncommon.

The knee may have a loose feeling to it, and may not be able to support the weight it usually does, and individuals may even have severe discomfort placing any weight on the knee at all. It may feel insecure when walking, causing some people to limp.

Patients may also experience minor pain on one side of the knee, with no associated swelling or other symptoms. Normal, low impact movements can also trigger periodic inflammation in the joint that may or may not disappear over time.

What Causes Knee Ligament Tears?

Partial or full rupture of the knee ligaments can stem from direct impacts to the knee, particularly those from contact sports, and can even be caused from bumping into something at the office or at home.

However, the knee ligaments are more susceptible to being twisted and overstretched when the joint surpasses its mobility limit. Ligaments will then rupture after the knee gets overloaded from one direction, as it tries to secure the joint in place by countering that force.

ACL tears and other knee ligament injuries can stem from:


  • Twists in the knee with the foot planted
  • Impacts to the knee
  • Overextending the knee
  • Jumping and landing on a bent knee
  • Suddenly stopping when running
  • A sudden shift in weight from one leg to the other

These types of injuries occur rather frequently in sports and activities like soccer, football, basketball, skiing, dance and gymnastics.

How Are Knee Ligament Tears Treated?

Depending on the age and lifestyle of the patient, both surgical and non-surgical options are available for the treatment of a torn knee ligament.

Ligaments, including those in the knee, receive no supply of blood and are, therefore, unable to heal themselves. That’s why reparation or replacement surgery remains the sole solution for repairing most tears. Nevertheless, older people or those with less active lifestyles may opt to restore the torn ligament by focusing on non-surgical approaches such as lifestyle changes, and exercise regimens to strengthen the muscles attached to the knee.

Immediate remedial actions for a damaged knee ligament include:

  • Inactivity and elevating the leg
  • Placing ice around the knee to alleviate swelling and bruising
  • Applying a compression bandage around the knee
  • Taking pain relief medicine

Knee ligament tears may also be alleviated by specific exercise programs to strengthen the muscles around the knee joint; using a knee brace during exercise and sporting activities to protect the knee; and, limiting intense physical activity.

When a patient experiences considerable knee imbalance as a result of a torn ligament, surgery may prove to be the most effective remedy; particularly if the injury is stopping the patient from pursuing routine activities like walking, bending down and twisting. Surgical restoration of the ligament can provide an alternative solution if other non-surgical methods haven’t produced the desired results.

During surgery, the surgeon will reconstruct the damaged ligament either by stitching it back together, or by grafting new tissue onto it, using a minimally invasive approach with an arthroscope (camera). The images returned from the camera are viewed on a large monitor and are used to guide small surgical instruments in order to repair the ligament.

Tissues for the “new” ligament may be procured from the kneecap tendon, from the hamstring tendon in the back of the thigh, or they may be provided by a cadaver graft. The graft will serve as a scaffolding for new ligament tissue to grow on.

What Happens After Knee Ligament Surgery?

The first few weeks after surgery, patients may experience some swelling and stiffness in the knee; pain medication may be prescribed by your physician. Most patients are able to walk without crutches 2-3 weeks after surgery.

Once the discomfort and swelling are under control, your surgeon will most likely recommend a rehabilitation program. Surgery is normally the first step to full recovery with rehabilitation and physical therapy playing a crucial role in getting patients back to their full knee strength and mobility. Diligently following a physical therapist’s program will greatly increase the chances of success after surgery. Exercises that don’t involve weight bearing on the knee, like swimming and cycling, can be particularly beneficial.

During the period from six weeks to six months after surgery, patients should be increasingly able to resume their regular level of activity.

Surgery can help many patients fully restore the function of their knee joint. It’s important to discuss and evaluate all the options with a surgeon and determine which one is best suited on an individual basis.


Discover more about our orthopaedic specialties and associated services.



Get directions and contact information for our offices.


Request an Appointment

Request your appointment just by filling out this simple form.