Major Amputation

Major

Major amputations are amputations where part of the leg is removed.  These are usually below the knee or above the knee.

Occasionally an amputation of just the foot can be performed with a cut through the ankle joint (Symes amputation). This is not suitable for the majority of patients, but can rarely be an option in some patients with diabetes.  It is particularly important for this amputation that the posterior tibial artery is patent and has a reasonable blood flow. This artery is found on the inside of the foot just below the ankle. Your surgeon may advise you if this operation may be possible.

It is usually possible before the operation (although not always) for the surgeon to decide at what level the amputation will be performed (above knee or below knee).  Sometimes gangrene or infection will only involve a toe or part of a foot and a limited or minor amputation can be performed.  This is only worthwhile if the surgeon thinks that the wound that is created will heal.  In some patients, it is better to try a limited amputation if there is a chance of healing, but to be prepared to proceed to a major amputation if healing doesn’t take place.

One of the most important factors in healing is the blood supply to the tissues.  If the blood supply is damaged or impaired it may not be possible for the tissues to heal even after a minor amputation.  If in the opinion of the surgeon the tissues will clearly not heal because of a poor blood supply it would be reckless to proceed with a minor amputation when really a major amputation is required.  Unfortunately, there is no test that can predict in every patient whether healing will take place and it is a matter of surgical judgement and experience whether a wound is likely to heal or not.

In general the more limited the amputation the lower the risks and the better the chances of walking.  It is better to have a below knee amputation when compared with an above knee amputation, because the chances of successfully walking after the operation are much better.  Unfortunately, not everyone is suitable for this operation and many people need to have an above knee amputation.  This may be because the blood supply to the lower leg is too poor and a below knee amputation would not heal properly.  If the knee cannot straighten out properly before the surgery (fixed flexion deformity), it will be impossible to walk with an artificial leg after the operation.  In these circumstances it may be better to undergo an above knee amputation.

Once an amputation stump is created it is a potentially vulnerable area that will require lifelong care and attention.  A major amputation wound is almost always closed with stitches or staples. A major amputation will take approximately 60-90 minutes to perform. Small plastic tubes are often inserted into the stumps before the end of the operation. These are drains which are used to take away any excess fluid that accumulates in the wounds. They are usually removed in the first 48 hours.