Amputation of The Lower Limb - Part Two

By Jonathan Blood Smyth

As peripheral vascular disease is the overwhelmingly frequent presentation there are seldom difficulties in establishing a diagnosis and treatment history. As the smaller blood vessels become gradually obstructed gangrene can develop in the toes and the areas which suffer pressure in the foot can develop ulcers. Bacterial invasion can follow with soft tissue infections and progression to infections in the bone. Persistent attempts at treatment can lead to a long period of minor amputations and other surgery which can leave a patient in pain and without useful function.

In cases where the amputation is due to injury or accident it is called traumatic amputation and may be related to severe fractures which are compound and the leg has badly damaged arteries and nerves. The best choice here might be a primary amputation versus attempted saving of the leg. Salvage attempts for the leg can result in the leg being painful and poor in function, limiting progress and encouraging depression. Once the injury has occurred a realistic assessment needs to be made as to the potential for the limb to function well and to decide to amputate should that lead to faster functional return and pain relief.

Keeping the length of the leg and achieving maximum functional independence is the main goal of the amputation process. Because the amputation cannot be undone the surgical decision must be a good one and the only obstacles then are the medical status of the patient in terms of coping with an operation. The abnormality of the limb has a medically negative effect on the overall health status of the patient and its removal may not only save the patient's life but allow them to restore their healthy status. Pre-operative preparation for the operation should prepare for their life after operation and include assessment by a social worker, psychologist and physiotherapist.

Surgical management of severe leg trauma has shown significant advances in the ability to perform microsurgery to the vascular structures, advanced fixation of fractures and techniques to promote revascularisation of tissues. Amputation may then be viewed as a failure if these techniques cannot save the limb, but viewing it as a reconstructive process is more positive, allowing an increase in useful functional capacity. Techniques of amputation have seen much less development and patients still consult with difficulties such as persisting pain, swelling, limited use of the prosthetic limb and feelings of instability.

Surgical technique is to maintain the length of the skin so that it can be folded over the stump and not be under any tension, the muscle is positioned over the cut bone end and opposing muscle groups may be stitched together and the nerves are cut when they are under tension and away from the bone ends so that they are in a non tension environment. One of the general rules for the length of an amputated limb is to allow 2.5cm of length for every 30cm of overall height. Once the operation is over the wound will have the chosen dressing applied and the patient be given post-operative painkillers.

After the immediate period post-operatively the patient will be assessed and treated by a physiotherapist who will review their respiratory condition, teach correct positioning of the remaining limb, encourage appropriate exercises, practice transfers and progress to walking with an aid if possible. Around the two week point the physiotherapist may progress to exercise for the affected extremity and start with a desensitisation programme for the operated part. This involves reducing the tenderness of the limb end so that it can cope with the pressures and stresses of wearing a prosthesis and weight bearing.

The planning and development for the provision of a prosthesis can be started around the six week point as the operated area will have settled to some degree, remembering that some patients will never be able to use a prosthesis well due to mental inability, overall weakness and poor standing balance. Many complications can potentially interfere with the patient working towards their maximum capacity. Vascular disease means potentially poor wound healing or breakdown and poor skin condition and there may be local swelling, joint stiffness, pain problems and phantom sensations. - 32188

About the Author:

Sign Up for our Free Newsletter

Enter email address here