When pain becomes unbearable: A lay summary of an algorithm for patients considering amputation

When pain becomes unbearable – An algorithm for improving outcomes for patients considering amputation

Introduction

Complex regional pain syndrome (CRPS) is a condition that causes long-lasting pain, which can feel unbearable, usually in an arm or leg. CRPS can start with a very minor injury or a severe injury, but the cause is not always clear. People suffering this condition sometimes describe feeling as though a kettle of boiling water is being poured over them, or like the body part is being crushed. Also, there are changes in what doctors call the autonomic nervous system functioning in the limbs, like sweating, swelling, turning an unusual colour, and hair growth. People often lose mobility in the limb.

Treatment includes pain-relieving medication, physiotherapy, occupational therapy or psychological support, and pain education. Some patients do not get better with treatment, and this can affect their quality of life. Some of them get so desperate that they ask for the limb to be amputated. It is hard to be sure if this will help or not, because after amputation, the patient can experience stump pain, phantom limb pain, or CRPS can come back in another part of the body. It can often be very hard for a person with CRPS to wear a prosthetic leg. Because an amputation cannot be reversed, doctors, along with the patient, need to be very careful in making this decision.

Aman et al (2022) proposed a flow chart (algorithm) to guide healthcare professionals in the decision-making process. They focus on a new surgical technique, targeted muscle reinnervation (TMR), as an alternative treatment for patients with severe CRPS.

What is Targeted Muscle Reinnervation (TMR)?

When an arm or leg is amputated, some nerves are left behind but no longer serve any purpose. TMR is a surgical procedure that surgeons can perform to reroute left-behind nerves. Doctors think TMR might make phantom limb pain less likely or less severe, or stop neuromas (painful tangles of nerves). There has not been enough research to know for sure whether it might help patients with CRPS, so it is a difficult decision whether to do this procedure with people with CRPS who are having an amputation.

Multidisciplinary board (MDB)

Martin Aman and colleagues shared their view that this kind of complex decision needs a Multidisciplinary board (MDB). This is when a group of professionals who have different expertise meet to make decisions together. Aman and colleagues suggest that the group should include:

• Orthopaedic surgeons (specialising in bones and joints)
• Plastic and reconstructive surgeons (specialising in ligaments, tendons, muscles, skin and nerves)
• Vascular surgeons (specialising in arteries, veins and lymphatic system)
• Physiotherapists (who help people to recover from injury and improve movement)
• Pain therapists
• Prosthetists (who make prosthetic – false – legs or arms)
• Psychiatry and psychology (who support mental health)
• Social services

All of these different professionals work together with the patient to decide and plan treatment.

Advanced algorithm for amputation

An amputation cannot be undone, so it is very important for the patients that the right decisions are made. The authors Aman and colleagues made a flow chart (algorithm) to help surgeons do their best to get this right.

1. The patient must have been trying other treatments, but they have not helped for 2 years or more.
2. There must be psychological support for the patient throughout the process. Also, mental health doctors (psychiatrists) need to check whether the patient has any mental health problems and give them treatment if they need it. They also need to check that the patient understands the possible risks and problems of an amputation.
3. fMRI is a type of brain scan that can show us what is going on in the brain. For people with CRPS, it can show how the nervous central system detects the limb, mainly when the limb has not been used normally for a long time.
4. Hybrid prosthetic fittings where possible – this means a trial process, which helps the patient understand what life with a prosthetic would be like.
5. After all the previous steps are done, the multidisciplinary board decides on the amputation alongside the patient.
6. The next step is the surgery, which combines amputation and TMR. Aman et al (2022) explain that they perform the amputation close to the place where the patient feels the pain.
7. Postoperative care. It is really important that doctors are ready with the right medicines to help with pain after the surgery. For people with CRPS, these might be different to standard pain killers. Once the stump is healing, the patient can go to the prosthetics service for prosthetic replacement. Finally, the patient must regularly go to outpatient appointments to continue checking that the results are positive and to deal with any problems.

Case example

To give an example of how the flow chart can work, Aman and his colleagues describe the case of a 16-year-old girl who had an injury in her left knee. Four years later, and after many treatments, the patient’s knee was stuck in an uncomfortable backwards-bent position caused by CRPS, and the patient also had an eating disorder. She was selected for the amputation and TMR surgery. After the healing of the stump, the patient could reduce the use of pain medication. Additionally, she was able to use a prosthetic leg.

Challenges and conclusions

Aman and colleagues highlight the need to continue analysing the use of new surgical treatments in patients with CRPS. The current guidelines do not state the value of amputation in this condition. That is why they decided to share the flow chart (algorithm) they follow, hoping that it can be helpful for others with complex cases of CRPS.