Torn Ligaments in the Knee: Symptoms, Torn Ligaments in the Knee, and Injuries to the Ligaments in the Knee Joint

In most cases, knee ligaments tear during sports. People who participate in sports involving frequent rapid changes of direction are particularly at risk. These include soccer, squash, and handball.

This can lead to what’s known as rotational trauma, in which the knee rotates while the lower leg remains fixed. This places such intense stress on the ligaments that they can no longer withstand the force and tear. The posterior cruciate ligament of the knee is particularly susceptible to damage in such cases.

Traffic accidents or falls can also damage the ligaments. Researchers also believe that there is a genetic predisposition to knee injuries. Previous knee injuries also increase the risk of a torn ligament in the knee.

At the exact moment of the injury, those affected experience acute and severe pain. Some patients report a tearing sensation or a “shifting sensation” in the knee. The tear is sometimes even clearly audible as a popping sound.

The exact location of the pain depends on which structure in the knee is affected. The pain associated with an anterior cruciate ligament tear is severe but subsides after a short time. Any strain on the knee triggers the pain again.

The knee also exhibits significant instability and wobbles. This is particularly noticeable when climbing stairs, as the thigh shifts backward relative to the lower leg. People who have suffered a tear of the posterior cruciate ligament can often compensate well for the instability by slightly bending their knees while walking. Typically, the pain is felt in the front of the knee and occurs mainly during sprinting or sudden stops.

A medial collateral ligament tear is characterized by severe pain and swelling on the inner side of the knee. Since small blood vessels are often injured in this area as well, a bruise (hematoma) forms. Just as with a cruciate ligament tear, the knee is unstable due to the ligament injury.

A torn lateral ligament usually causes tenderness in the area of the torn ligament. The knee is unstable due to

• the severe pain,
• the swelling, and
• the instability of the joint

.

Even the description of how the accident occurred and the resulting symptoms can lead the doctor to suspect a torn ligament. However, to make a definitive diagnosis, the knee joint must be examined thoroughly.

To do this, the doctor uses various stability tests to check whether the joint has an abnormally large range of motion.

To rule out cruciate ligament tears, the so-called Lachman test and the drawer test are used. If, during this test, the lower leg can be moved forward or backward relative to the thigh to an unnatural degree, this is known as the drawer sign.

However, the range of motion varies from person to person. The doctor therefore always tests both sides to compare the affected knee with the healthy knee.

Imaging techniques such as

• an X-ray,
• magnetic resonance imaging,
• an ultrasound examination, and
• arthroscopy

can also confirm the diagnosis. They also help rule out complications such as injuries to the bone or other joint structures.

If joint effusion has developed as a result of the accident, the doctor can puncture the knee to relieve pressure and drain the fluid using a hollow needle. The fluid can be analyzed in the lab and also provides clues as to the cause. If blood is found in the extracted fluid, this indicates a torn ligament.

In the case of a torn ligament, first aid is crucial. The RICE principle should be followed:

• Rest – the joint should be immobilized
• Ice – early cooling can reduce swelling
• Compression – a compression bandage also helps reduce swelling
• Elevation – the leg should be elevated above heart level if possible

These measures limit the damage following a sports injury or accident.

In further treatment, a torn ligament can be treated either conservatively or surgically. With conservative treatment, patients are fitted with a (removable) splint. This stabilizes the joint and absorbs stress until the injury has healed.

Pain-relieving, decongestant, and anti-inflammatory medications can further alleviate symptoms.

If the knee joint no longer has sufficient stability or if the injury is complicated and extensive, surgery may be necessary. The surgical procedure is usually minimally invasive and can be performed on an inpatient or outpatient basis.

The surgeon replaces the torn ligament with a new one made of either synthetic or autologous materials (ligament reconstruction). For example, healthy tendons from the patient’s leg muscles may be used for this purpose. The video demonstrates how ligament reconstruction is performed for a cruciate ligament tear:

Physical therapy can promote healing both during conservative treatment and after surgery. Special exercises are designed to restore stability to the knee joint and help the joint adapt to the stresses of daily life.

The prognosis depends on

• the severity,
• the patient’s age, and
• the appropriate treatment

.

If the tear is treated immediately, the chances of a quick and uncomplicated recovery are good. The exact timing of when the knee will be ready for activity again should be discussed with the treating physician.

Generally, however, it can take up to a year for the knee to be fully fit for sports again and able to withstand all types of stress.

How can you tell if you have a torn knee ligament?

Key signs of a torn ligament include a loud popping or tearing sound at the time of the injury, followed by immediate, severe pain. The knee often swells significantly within a short time as blood from the torn vessels leaks into the joint (hemarthrosis). Another key symptom is instability: the knee gives way under load (“buckling” or “giving-way phenomenon”), and the person affected feels as though they can no longer control their leg.

Which ligaments in the knee can tear?

Four main ligaments provide stability in the knee joint: the anterior cruciate ligament and the posterior cruciate ligament inside the joint, as well as the medial ligament and the lateral ligament on the sides. The anterior cruciate ligament is most commonly affected by a tear, often in combination with injuries to the meniscus and the medial collateral ligament (unhappy triad). An isolated tear of the lateral collateral ligament is rather rare.

How is a torn ligament in the knee diagnosed?

If a ligament tear is suspected, the doctor performs stability tests (e.g., Lachman test, drawer test). During these tests, the doctor checks whether the lower leg can be moved excessively relative to the thigh. To confirm the diagnosis and rule out accompanying injuries to the cartilage or meniscus, magnetic resonance imaging (MRI) is the gold standard. It visualizes the soft tissues and the exact location of the tear.

How does conservative treatment work?

Conservative treatment is often an option for isolated medial collateral ligament tears or for patients with lower athletic demands. The injured knee is first immobilized with a brace to support the ligament’s healing. In conjunction with this, physical therapy and targeted muscle strengthening help compensate for the lack of ligament stability by building strong muscles around the knee.

When is surgery necessary for a ligament tear?

Surgical treatment is usually recommended if the knee remains unstable, if the anterior cruciate ligament is torn in young, active patients, or if multiple structures in the knee (e.g., meniscus and ligament) are injured at the same time (combined injury). The goal of surgery is to restore the anatomy and prevent secondary damage such as osteoarthritis, so that the knee can once again bear a full load for sports and work.

How long does it take to recover from a torn ligament?

The healing time depends on the severity of the injury and the chosen treatment. A medial collateral ligament tear treated conservatively often heals within 6 to 8 weeks. After cruciate ligament surgery, rehabilitation takes significantly longer: it often takes 3 to 4 months before light sports such as jogging are possible, and stop-and-go sports are usually not permitted again until 9 to 12 months have passed.

How does a torn ligament in the knee occur?

A torn ligament in the knee is usually caused by indirect trauma without external force. Common mechanisms include twisting the knee while the foot is planted (e.g., getting cleats caught in the grass) or hyperextension. The most common cause of a torn ligament is sports involving rapid changes of direction and jumps.

What can I do to stabilize my knee?

In addition to immediate first aid (the RICE method: Rest, Ice, Compression, Elevation), strengthening the thigh muscles (quadriceps and hamstrings) is crucial. Strong muscles act like an active support and can compensate for some instability in the ligaments. Coordination exercises on a wobble board also improve reflexes and help prevent future injuries.