Phantom Knee Pain: Symptoms, Causes, and Treatments

Phantom Knee Pain: Symptoms, Causes, and Treatments

Losing a limb is a life-altering and traumatic event, and many who have gone through this are horrified to find that they still feel pain where their limb used to be. Sensation in a missing limb after amputation is a common experience for amputee patients.

 

What is phantom knee pain?

Phantom knee pain is the perception of some form of discomfort or sensation in a knee that is no longer there due to amputation or surgery. This phenomenon is not well understood by researchers, but is experienced by a vast majority of amputees in the United States.

There are two types of phantom knee pain: residual limb pain (RLP) and phantom sensations. RLP refers to pain that originates from the site of the amputation. This pain is usually experienced less often as the amputation site heals. Phantom knee sensations refer to pain or discomfort in a limb that no longer exists.

 

Symptoms of phantom knee pain

When someone experiences phantom knee pain, that sensation is completely real to them despite the knee no longer being attached to their body. This can be an enraging experience that perplexes both the person suffering and their physicians. 

Phantom sensations usually begin immediately following the loss of the knee and anyone who has had an amputation is at risk of developing them.

Common sensations of phantom knee pain

Phantom sensations can include various forms of pain and discomfort. These symptoms may be fleeting or last for long periods of time.

These are the most common phantom knee pain sensations:

  • Aching
  • Burning
  • Throbbing
  • Itching or tingling
  • Clamping or pinching

 

Risk factors for phantom limb pain

Between 80-95% of amputation patients report experiencing some form of phantom limb sensations. Some risk factors can increase the possibility of triggering phantom knee pain.

Angina

Angina is a condition in which blood flow to the heart is restricted, resulting in chest pain. People with angina describe the feeling as tightness, pressure, and heaviness in their chest.

Shingles

Painful rashes that develop on one side of the face or body are called shingles. In the days leading up to the onset of shingles, people may feel itching or tingling in the area where the rash will appear.

Stress

Anxiety, depression, and stressful situations can all increase the chances that an amputee patient feels phantom sensations where their knee was. 

 

Causes of phantom knee pain

The exact causes of phantom knee sensations are unclear, but doctors have a better understanding of why patients may feel residual limb pain.

Nerve damage

Nerve damage can cause a person to have pain at the site of their amputation. Nerve entrapment happens when there is pressure on a nerve. This can occur if something is pressed or wrapped incorrectly during the amputation surgery.

Improper healing after surgery

When the surgery site heals improperly, patients may feel pain during the healing process and after healing is complete. Too much scar tissue and pressed nerves can contribute to residual limb pain.

 

Diagnosis of phantom knee pain

Accurate diagnosis of the cause of residual and phantom knee pain is important. Examinations and procedures physicians will perform to better understand your sensations include:

Physical exams

During a physical exam, your doctor will inspect the amputation site for signs of sores, infection, or masses. 

Diagnostic Technology Testing

CT scans, MRIs, and ultrasounds may be used to get a more detailed view of your surgery site. This will also allow doctors to rule out other causes of pain, such as bone abnormalities and infection.

Additionally, Electromyograms (EMG) and Nerve Conduction Studies (NCS), which check on how a patient’s muscles and nerves are functioning. The results from this test will help a pain specialist diagnose the severity of a patient’s condition, and accurately map the appropriate treatment options.

Blood tests

Blood tests are used to screen for other possible causes of pain.

 

Treatment options for phantom knee pain

Treatment for residual limb sensations requires treating the underlying cause of pain at the amputation site. For phantom knee pain, treatment may involve a combination of therapy and medication.

Cognitive behavioral therapy

Cognitive behavioral therapy (CBT) is a type of psychological treatment used to improve the quality of life for certain individuals. CBT addresses unhelpful thought patterns and poor behavior patterns and teaches better coping skills.

Mirror Therapy

Mirror therapy is proven to reduce phantom knee pain in about a month. During mirror therapy, a knee amputee sits in front of a mirror during a phantom pain flare. The person makes movements and watches their limbs to stimulate positive sensations in the brain. Mirror therapy is more successful with single-limb amputees than with those who have lost both knees.

Medications

Certain medications are commonly prescribed to people suffering from phantom knee pain. 

Nerve Stimulation

Nerve stimulation therapies are emerging as a way to manage phantom knee pain and avoid taking medication. Electrical currents, implanted electrodes, and biofeedback are all used to prevent pain that stems from damaged nerves.

 

Frequently Asked Questions

Is phantom knee pain the same as residual knee pain?

Phantom knee pain and residual knee pain are two different sensations that are experienced by amputees. Phantom knee pain is a sensation in a knee that no longer exists. Residual knee pain is pain at the site of the amputation.

Does exercise help phantom knee pain?

Exercise might alleviate anxiety and depression for those suffering from phantom knee pain. Exercises that are performed in front of a mirror may be especially effective at helping relieve some phantom knee sensations.

Is phantom pain psychological?

Phantom pain is a completely legitimate pain response initiated by the brain. Psychological elements may trigger phantom pain or make it worse and certain psychological therapies have proven to be effective at preventing phantom sensations from occurring again.

What part of the brain controls phantom pain?

The sensorimotor cortex is the part of the brain most often blamed for causing phantom limb pain. This part of the brain is involved with the execution of body movements, and is in charge of maintaining joint homeostasis.