Pain Management In The Amputee

The pain management and treatment team includes the patient, physician, prosthetist, physical therapist, and pain management specialist.

Pain is one of the most common complaints of amputees. Even after surgery wounds are healed, amputation-related pain is reported in as many as 80% of amputees surveyed. Pain is strongly associated with slow walking speed, difficulty using a prosthesis, and lower quality of life. While the pain experienced by amputees includes cancer pain and musculoskeletal pain, the two pain syndromes unique to amputees are phantom limb pain (PLP), and residual limb pain (RLP). Due to the complexity of these systems, success often is achieved only with a team approach to treatment. The treatment team includes the patient, physician, prosthetist, physical therapist (PT), and pain management specialist. Each professional provides a unique perspective on the potential source of the pain and treatment options.

Residual limb pain is felt by the amputee in the “stump.” It can be caused by internal or external factors. The most common external cause is an ill-fitting prosthesis. While internal factors include poor blood flow (ischemia), infection and inflammation, they are more often the result of the body’s attempt to repair itself after the surgery.

Examples are tight scar tissue, overgrown nerve endings (neuroma). And bone spurs. Some RLP can be successfully treated by a single team member (e.g. physician prescribes antibiotics to treat infection). Most RLP requires intervention by two or more team members. For example, pain at the end of the bone when the amputee walks on the prosthesis can be addressed by the prosthetist re-aligning the socket of the prosthesis, the PT training the amputee in a better gait pattern, and/or the physician prescribing medication. The entire team may be involved in treating a neuroma: the physician can order medications to be taken by mouth, injected into the neuroma, applied directly to the skin, or delivered by the PT with iontophoresis. If the neuroma is a problem only when the prosthesis is used, the prosthetist may be able to modify the prosthesis to remove direct pressure from the sensitive area. A pain management specialist or surgeon may be called upon for procedures such as neuroablation to deaden the nerve, or revision to move the neuroma deeper into the soft tissue for additional protection.

Phantom sensation—non-painful sensations felt in the missing body part—are experienced by virtually all amputees. An estimated 60-85% of amputees will experience painful phantom sensations. PLP can range from mild to very intense, and have been described as burning, crushing, stabbing, and the sensation that the limb is in a painful position. PLP is neurogenic, occurring within the central nervous system, but the exact mechanism is not clearly understood. Recent studies suggest that PLP is caused by neural adaption, changes to the structure of the brain as the nervous system adapts to the amputation. Like a neuroma, PLP is best treated by the entire team.

Treatment usually begins with medications taken by mouth. For clients who experience side effects, some medications can be administered with iontophoresis or absorbed through the skin. Increasing sensory input to the residual limb decreases PLR. A TENS unit, a pager-sized electrical stimulator, applies a mild tingling sensation. Compression can be applied by wrapping with an ACE bandage or wearing a shrinker (an elasticized sock provided by the prosthetist) and simply by wearing the prosthesis. Very early prosthetic fitting (within one month of amputation) is recommended for arm amputees to control neural adaptation related to PLP.

Residual limb pain and phantom limb pain are two types of pain experienced by the majority of amputees. Successful treatment can be achieved by comprehensive evaluation and intervention by a team of professionals.