Pain after leg amputation: phantom limb and residual limb pain

Two kinds of pain, and why the difference matters

After an amputation, the nerves that once served the limb are cut. The pain that follows falls into groups that need to be told apart:

• Phantom limb pain feels as if it is coming from the missing foot or leg.
• Residual limb pain (sometimes called stump pain) is felt in the part of the limb that remains. A neuroma is one cause. Others include pressure from the prosthesis, skin problems, poor circulation and infection.
• Phantom sensations that are not painful, such as the feeling that the foot is still there, are different from pain.^[1]

The two painful types can occur together. Sorting out which is which guides the treatment. Our pages on phantom limb pain and residual limb neuroma pain cover each in detail.

How common it is

Estimates vary a lot between studies:

• In a pooled analysis of lower-limb amputations for non-traumatic causes, the pooled prevalence of any post-amputation pain was 61%, phantom limb pain 53% and residual limb pain 32%. The studies differed widely from one another.^[2]
• After lower-limb amputation for poor circulation (dysvascular amputation), a pooled analysis found that 69% of people reported phantom limb pain.^[6]
• Another meta-analysis of lower-limb amputations found the prevalence of residual limb pain to be 59% and symptomatic neuroma 15%.^[3]
• A meta-analysis of 1,329 lower-limb amputees found that about 19% developed a symptomatic neuroma, and about 30% in studies that followed people for at least three years, compared with 3% in studies with shorter follow-up.^[4]

The take-away is that persistent pain is a common part of recovery for many people, and neuroma pain may show up months or years after the amputation.

What contributes to the pain

Phantom limb pain seems to involve changes in the brain and spinal cord as well as in the nerves of the residual limb. Pain that was present before the amputation, the level of the amputation, pain in the stump and phantom sensations have been linked to a higher risk.^[1,7,8] Residual limb pain has more local causes, and a neuroma is the nerve-related one that surgery can address.^[3]

Evaluation

A full evaluation looks at the whole limb:

• The skin and soft tissue for pressure areas, wounds, infection or swelling.
• The prosthesis fit, with your prosthetist.
• The circulation, particularly if the amputation was for vascular disease.
• The nerves. A tender, tingling spot over a nerve end often points to a neuroma. Ultrasound or MRI can help find it, and a small anaesthetic injection around a suspected neuroma that temporarily relieves the pain can help confirm it. Diagnostic injections and imaging are arranged with another specialist.

Treatment overview

• Adjusting the prosthesis and protecting the skin
• Medicines for nerve pain, prescribed by your physician
• Therapy, including desensitization, graded activity and rehabilitation. Evidence for individual approaches varies; for example, a review of placebo-controlled trials of mirror therapy for phantom pain did not find clear evidence of benefit, though the trials were small.^[9]
• Nerve surgery for a neuroma that is confirmed and painful: removing it and relocating the nerve, or giving the nerve a muscle target, as in targeted muscle reinnervation or a regenerative peripheral nerve interface

In a review of 17 studies of the two nerve procedures, both were linked to reduced neuroma pain in 75 to 100 percent of patients and reduced phantom limb pain in 45% to 80%, with complication rates from 13% to 31%. Most studies were small and only one was a randomized trial.^[5]

Prevention at the time of amputation

Because a neuroma forms whenever a nerve is cut, some surgeons manage the nerve ends at the time of the amputation. In a study of 105 limbs, a neuroma recurred in 19% of those who had targeted muscle reinnervation later, after a neuroma had formed, compared with 1% in those who had it at the time of amputation.^[10] If an amputation is planned, ask your surgical team how the nerves will be managed.

When to seek care

Consider an evaluation if pain in the residual limb has lasted more than a few weeks, is burning or electric, is focused on one tender spot, or keeps you from wearing your prosthesis.