What a Knee Contusion Is and How It’s Treated

A bruised knee may sound like a minor inconvenience, but a knee contusion can cause surprising discomfort and sometimes signal deeper injury. Whether from a fall, sports impact, or accidental bump, contusions to the knee vary in severity from simple surface bruises to painful bone involvement.

If you're dealing with knee pain, swelling, or stiffness after an injury, here's what you need to know about identifying and managing a knee contusion and when it's time to call your doctor.

What Is a Knee Contusion?

A knee contusion is the medical term for a bruise around or within the knee joint, usually caused by blunt trauma. Common signs include:

• Swelling and tenderness

• Pain with movement

• Skin discoloration (red, blue, purple, or yellow)

• Stiffness or difficulty walking

• Sensitivity to touch

These symptoms can make everyday tasks like getting up from a chair, climbing stairs, or walking more difficult especially in the first few days post-injury.

Types of Knee Bruises

Not all bruises are the same. Depending on how deep the injury goes, a knee contusion may fall into one of three categories:

• Subcutaneous: A surface-level bruise with broken capillaries just beneath the skin.

• Intramuscular: A bruise within the muscle tissue that may not show obvious skin discoloration but still causes soreness and swelling.

• Periosteal (Bone Bruise): A deeper injury affecting the tissue around the bone, often only visible on an MRI scan. Bone bruises can take longer to heal and may require medical attention.

While bone bruises are more severe, they are still less serious than fractures.

What Causes a Knee Contusion?

A contusion typically results from direct impact or trauma strong enough to damage small blood vessels, allowing blood and fluid to leak into surrounding tissue.

Common causes include:

• Slips, trips, and falls

• Sports collisions or tackles

• Accidents involving impact to the knee

• Repetitive strain or blunt force injuries

People taking blood thinners, or those with certain medical conditions, may bruise more easily and should monitor any unexplained bruising closely.

How to Treat a Knee Contusion at Home

Most minor knee contusions heal without the need for medical intervention. Here’s how to support the healing process:

1. RICE Protocol:

   • Rest: Avoid high-impact activities and allow the tissue to heal.

   • Ice: Apply for 15–20 minutes several times a day. Never place ice directly on the skin.

   • Compression: Use a wrap or brace to reduce swelling.

   • Elevation: Keep your knee above heart level to limit fluid buildup.

2. Over-the-Counter Pain Relief:
   Medications like acetaminophen or ibuprofen can help manage pain and reduce inflammation.

3. Supportive Devices:
   In some cases, using a knee brace, cane, or shower chair can help you stay mobile while minimizing strain on the joint.

4. Gentle Movement:
   Don’t completely immobilize the knee unless advised by a doctor. Light movement supports blood flow and tissue healing, as long as pain allows.

When to See a Doctor

While most knee bruises improve on their own, seek medical advice if you notice:

• Significant swelling within 3–4 hours of injury

• Difficulty bearing weight or bending the knee

• Persistent pain or bruising beyond two weeks

• Numbness or tingling around the knee

• A history of unexplained or frequent bruising

These may indicate more serious injuries like a ligament tear, meniscus injury, or even a bone fracture. Your provider may order imaging (like an MRI) to rule out these possibilities.

Medical Treatment Options

If complications or underlying conditions are identified, treatment may include:

• Fluid drainage to relieve pressure from swelling

• Supplements (such as calcium, vitamin D, or protein) to support bone and tissue healing

• Physical therapy to restore strength, flexibility, and range of motion

• Referral to a specialist if ongoing issues or additional conditions are discovered

How Long Does Recovery Take?

• Mild knee contusions: Typically heal within 2–4 weeks with proper self-care.

• Moderate to severe bruises or bone involvement: Recovery can take several weeks to a few months, especially if other injuries are present.

Staying consistent with rest and gentle rehabilitation can shorten recovery time and help prevent long-term issues.

Can a Knee Contusion Lead to Long-Term Problems?

Yes. In some cases, unresolved or severe knee contusions especially those involving the bone can increase the risk of knee osteoarthritis later in life. It’s important to:

• Monitor symptoms

• Avoid returning to high-impact activity too soon

• Stay active in a low-impact way to preserve joint function

Takeaway

A knee contusion might seem minor, but it deserves attention especially if pain or swelling persists. Most bruises heal on their own with rest and basic care, but always listen to your body and seek medical guidance when needed. Early intervention can help prevent complications and protect your joint health in the long term.

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