Knee pain triggered by a fall can signal injuries as minor as a bruise that you can treat at home to as serious as a torn ligament or fracture that may require surgery to repair.

Paying close attention to the severity and location of the knee pain you are experiencing can help you determine the type of injury you’ve sustained and whether medical attention is necessary.

Keep in mind that knee pain associated with difficulty standing or walking should be considered a medical emergency.

Read on to learn about knee injuries that can occur after a fall and how to tell the difference between minor injuries that can be treated at home and more severe ones that require medical attention.

Here are the eight most common knee injuries — from minor to severe — that can occur after a fall.

1. Abrasion

An abrasion is another term for a scrape. This occurs when the skin rubs against a rough surface, such as asphalt or cement.

A minor abrasion takes off just the outer layer of skin (epidermis) and can be treated at home. Serious abrasions that involve bleeding and more layers of skin may need medical attention.

2. Laceration

A laceration is a cut or puncture wound that causes a tear or hole in the skin.

If you fall and land on something sharp like a nail, you can end up with a laceration. Like abrasions, lacerations can be minor with little or no bleeding, or very deep requiring medical attention.

Lacerations caused by rusty objects such as a nail, may also put you at risk for tetanus. Seek immediate medical attention if this happens.

3. Contusion

A knee contusion or bruise is a common injury if you fall on a hard surface.

The impact can cause a blood vessel or capillary in the skin or muscle underneath to leak blood into the surrounding area, creating the black and blue sign of a bruise.

A bruised knee is usually treated at home with rest, ice, elevation and an over the counter anti-inflammatory medication [such as ibuprofen] as needed.

4. Sprain

A knee sprain occurs when one — or more — of the ligaments in the knee is overstretched.

A ligament is a structure that connects one bone to another. If you fall hard or your knee is struck by something heavy or powerful — think of a football tackle — you may experience a knee sprain.

If the sprain is minor, you can usually rest at home and treat it yourself. See your doctor if:

  • there’s significant swelling
  • severe pain
  • you have a lot of difficulty moving your knee

5. Torn meniscus

The meniscus is a rubbery piece of cartilage that sits in between the femur and tibia and helps to cushion and support the two bones.

A meniscus tear usually occurs when making a sharp turn in sports such as basketball or football, but a hard fall can also result in a meniscus tear.

Some meniscus tears can be treated conservatively (without surgery); however, persistent pain and/or swelling may be signs that you need an operation to treat your torn meniscus.

6. Tendon tear

There are two main tendons in the knee:

Patellar tendon tears are more common, and both injuries can result from a fall on the front of your knee or from missing a step and landing awkwardly.

7. Torn ligament

The knee contains four main ligaments that connect the tibia to the femur (thighbone) and allow the knee to move forward, backward, and rotate side to side:

  • anterior cruciate ligament (ACL)
  • posterior cruciate ligament (PCL)
  • medial collateral ligament (MCL)
  • lateral collateral ligament (LCL)

A high-impact injury such as a fall or a blow to the side of the knee can cause one or more of these ligaments to tear.

Surgery is often necessary to repair a torn ligament. Without proper care, a torn ligament can lead to chronic pain and disability of the injured knee.

8. Knee dislocation

A dislocated knee occurs infrequently, but it’s a very serious injury and requires emergent medical attention.

Knee dislocations usually occur following high-energy injuries such as car accidents, falls from significant heights, etc., but low energy injuries can occur and push the thighbone out of alignment with the shinbone causing a dislocated knee.

Complications such as blood vessel and nerve damage are not uncommon following a dislocated knee and require immediate medical attention.

A knee scrape or bruise can be painful. However, this kind of injury usually does not require medical attention unless there’s bleeding that cannot be controlled.

Other symptoms that indicate the need for prompt medical attention include:

  • Hearing or feeling a “pop” sound as you fall as this is often associated with a torn ligament.
  • A feeling that the knee is unstable, buckles, or gives way is also commonly associated with a torn ligament.
  • Swelling of the knee can indicate a torn ligament or fracture.
  • Your knee feeling warm to the touch after a fall could be a sign of inflammation stemming from an injured tendon or muscle. Warmth can also be a sign of infection or bursitis.
  • Being unable to put weight on your knee may mean that there’s structural damage to the joint.
  • Bleeding from a cut or scrape persisting after several minutes may require medical attention.
  • The area around a cut or scrape turning red or swollen or leaking pus some time after the injury can signal an infection.

Knee pain is a symptom common to most knee injuries and chronic knee conditions.

To diagnose the cause of knee pain after a fall, your doctor will start by reviewing your medical history to determine if an underlying condition, such as an unstable knee joint, led to the fall.

Your doctor will also do a physical examination of the knee.

You will be asked to bend and straighten your leg (if possible) as the doctor feels for any dislocation of the kneecap or other signs of an injury to the bones, ligaments, or tendons in the knee.

Imaging may also be necessary:

Treatment for a knee injury caused by a fall usually involves rest and if necessary, a brace to stabilize the joint. In most cases, anti-inflammatory pain relievers, such as ibuprofen (Advil, Motrin), may be helpful.

Minor knee injuries can often be treated at home. However, it’s important to see a doctor if symptoms worsen or if the pain is accompanied by:

  • significant joint swelling
  • an inability to bear weight
  • a feeling of giving way
  • other signs of ligament or tendon damage

When the injury is serious, surgery may be necessary to restore function and eliminate pain.

Home treatment

With a cut or and scrape, clean the wound and leave it uncovered if it’s minor and not bleeding.

For a more serious knee abrasion or laceration that’s bleeding, clean it and cover it with a clean cloth or bandage. Applying direct pressure to the area will stop most minor bleeding. Keep the knee elevated and take an over-the-counter pain reliever if necessary.

For knee bruises, sprains, and more serious injuries follow the RICE protocol:

  • Rest by staying off the injured leg as much as possible for the first day or two.
  • Ice your knee or use a cold compress for intervals of 15 to 20 minutes (on, then off) for the first day. Wrap the ice or cold compress in a thin towel or cloth to avoid skin damage.
  • Compress the knee by wrapping it in an elastic bandage to help decrease swelling.
  • Elevate the injured knee on cushions when icing it or whenever you’re lying down.

Medical treatment

Here are some possible medical treatments for more serious knee injuries:

  • A long or deep laceration may require stitches.
  • Knee injuries that involve certain tendons and ligaments can be treated conservatively with physical therapy and a brace to help keep the knee stable while it heals.
  • Surgery may be needed to repair certain fractures as well as some ligament and tendon injuries.

Following many knee injuries, physical therapy is advised to restore knee strength and range of motion to match their levels before your fall as closely as possible.

Your recovery time will depend on the severity of your injury and whether surgery is required.

A sprained knee, for example, may heal completely in 2 to 4 weeks. However, complete recovery following surgery for a torn ligament may take 6 to 12 months.

The cause of knee pain after a fall may be a surface injury, such as a scrape or cut, or more significant involving bones, ligaments, or tendons.

In addition to pain, symptoms such as significant swelling, a feeling of buckling or giving way, and an inability to put your weight on the injured knee should prompt you to seek medical attention.

Minor knee injuries can often be treated with rest and a knee brace, while tears of a ligament or tendon may require surgery.

Following through with physical therapy, if prescribed, after a knee injury is also critical to ensure a full recovery. Doing so will minimize your pain, maximize your recovery, and restore the strength and range of motion of your knee.