Amputation – Neuroma and Phantom Pain
Any amputation can cause chronic pain - from a fingertip to a whole limb. These issues are treatable, allowing patients to use their hand or wear a prosthesis without pain.
When a body part is removed, nerves are cut in the process. The cut ends of the nerves left behind are still alive. They usually sprout, and with nowhere to go, form “bulbs” of raw nerve ends called neuromas. Neuromas may be painful to the touch and cause electric, shock-like sensations when bumped. Neuromas can also send constant neuropathic pain signals to the brain.
Phantom pain is the feeling of the missing body part. The brain can still truly believe that the missing part is still there, and is “on fire”. Phantom pain can be treated the same was as neuroma pain.
Any removed tissue can lead to amputation pain – both neuroma and phantom pain. This can happen no matter where or how much tissue is missing. A fingertip, a leg, a breast – any tissue that was lost during a traumatic injury, or from an operation.
Patients describe the feeling as burning, itching, numb and deep aching pains. These nerve ends can also get caught up in scar tissue, causing them to be
tethered and “pulled on” when the residual body part is moved. This increases pain, and prevents patients from being able to do certain activities.
Surgery is highly successful in eliminating or greatly reducing amputation pain. Depending on the cause, different operations could be recommended:
Neuroma and phantom nerve pain – segments of the injured nerves can be cut out, thereby stopping the pain signals from reaching the brain.
Heterotopic ossification (HO) – just as the cut nerves can sprout, excess bone can grow off of the cut ends of the bone and cause pain. This bone can be removed if found to be the cause of the pain.
Fluid (bursa) or scar tissue – surgery can also be helpful for these issues.
Doctors diagnose amputation pain in three steps:
1. A history of pain in the residual limb.
- The pain is usually be made worse by touching the area, moving the limb, or wearing a prosthesis.
- The pain is often sharp, burning, and/or stabbing, but can also be dull and deep.
- Bumping or hitting the painful spot can send electric shocks up or down the limb.
2. A physical exam
- The area of pain usually corresponds to known pathways of major nerves.
- Causes other than injured nerves are considered – these may be inflammation or infection of the tissues, extra bone growth, or fluid build-up.
3. Testing
- To confirm that an injured nerve(s) is the cause of pain, a local anesthetic (nerve block) can be performed. This is a small “shot” of numbing medicine performed in the office. If the pain goes away temporarily, then it is highly likely that it is due to damage of that specific nerve.
- X-rays help to determine if there is extra bone growth that can be painful (known as heterotopic ossification, HO). This growth can be surgically removed.
- MRIs can diagnose scar tissue, inflammation and fluid build up as a cause for the pain, which can then be treated.
Surgeons at Neuropax use the two newest procedures – RPNI (regenerative peripheral nerve interfaces; muscle/skin grafts on the nerve ends) and TMR (targeted muscle reinnervation; nerve transfers) to improve the outcomes of nerve surgery for chronic pain. These techniques have been shown to significantly decrease the chances for pain.
- Regenerative Peripheral Nerve Interfaces for the Treatment of Postamputation Neuroma Pain: Woo SL, Kung TA, Brown DL, Leonard JA, Kelly BM, Cederna PS: A Pilot Plast Reconstr Surg Glob Open 4(12): e1038, 2016. Amputat
- Regenerative Peripheral Nerve Interfaces for the Management of Symptomatic Hand and Digital Neuromas. Hooper RC, Cederna PS, Brown DL, Haase SC, Waljee JF, Egeland BM, Kelley BP, Kung TA: Plast Reconstr Surg Glob Open 8(6): e2792, 2020. Amputat
Nerve Surgery Helps Relieve Chronic Pain
The majority of patients with chronic pain report significant decreases or complete resolution of their pain following nerve surgery. Most patients describe the ‘nerve pain feelings’ are improved as soon as the following day. Discomfort from the operation is frequently described as a completely different sensation, which subsides in the next few weeks.