Management of Stage 6 Unsalvageable Foot

The stage 6 foot cannot be saved and needs a major amputation, either below, through, or above the knee.

Pathways to amputation

  • Neglected callus destroys a neuropathic foot.
  • Neglected injury in a neuroischaemic foot
  • Eye–foot syndrome
  • Chronic ischaemia
  • Acute ischemia
  • Mismanaged Charcot’s osteoarthropathy

Major amputation is sometimes inevitable, particularly in neuroischaemic patients. However, rehabilitation of the diabetic amputee is extremely difficult and is characterized by long stays in hospital. Major amputation, therefore, must not be taken lightly. Morbidity and mortality associated with major amputation in diabetes are very high. Within 3 years of amputation, 50% of major amputees will be dead and of the survivors, half will have lost their remaining leg. After 5 years, only 30% of major amputees with diabetes will survive. Survival of above-knee amputees is significantly less than below-knee amputees, and relative mortality is higher for females than for males. In the presence of diabetes, the risk of developing congestive cardiac failure following amputation is twice that of those who are non-diabetic. There is a need for amore aggressive approach to the management of cardiac failure and cardiovascular risk factors in those who undergo amputation and have diabetes.

 

Major amputation in the neuroischaemic foot is necessary in the following circumstances when:

  • Overwhelming infection has destroyed the foot and threatens the patient’s life
  • There is severe ischaemia with rest pain that cannot be controlled
  • Extensive necrosis secondary to a major arterial occlusion has destroyed the foot.

Major amputation in a neuropathic foot should be a very rare event and necessary only when:

  • Infection has irretrievably destroyed the foot
  • Charcot’s osteoarthropathy has destroyed the ankle joint, attempts at external stabilization have been unsuccessful and internal fixation is not possible.

 

The decision to amputate

When a major amputation is being considered the following factors should be addressed by the multidisciplinary team:

  • Social factors: some practitioners believe that patients who face many weeks or months of treatment should be offered a major amputation as a serious treatment option and that amputation can often be viewed very positively. If life expectancy is very limited it cannot not be regarded as a success if the patient spent much of his remaining days in hospital to save his leg
  • Emotional factors: many patients and their families react with horror to the idea of a major amputation.Depression after amputation is common
  • Financial factors: diabetic foot patients may be regardedas ‘expensive’ patients in terms of: Number of bed days occupied Consumption of expensive antibiotics ,Costly interventions.

However, major amputation is not cheap and involves: Accumulated costs of rehabilitation,Prosthetics service,Loss of earnings,Costs of special services

  • Functional factors: in elderly, frail diabetic patients the functional results of amputation are usually poor. Many patients do not walk again and never return to independent living.

 

Choice of level of amputation

The level of amputation should be carefully considered to ensure that there is sufficient perfusion to achieve wound healing. When possible, a below-knee amputation should be carried out to conserve the knee joint and aid the fitting of a prosthesis. Preserving the knee joint lowers the energy expenditure necessary for walking. The cardiovascular cost for walking and foot plantar pressures in the opposite limb both increase in direct proportion as the amputation becomes more proximal. Postoperative mortality  is higher in above-knee amputations (10–40%) than in below-knee amputations (5–20%).The aims are:

  • To keep the amputation as distal as possible
  • To amputate above painful, cold, pale or discoloured tissue
  • To amputate below warm, pink, well-perfused tissue.

About one-fifth of transtibial amputations and knee  disarticulation amputations undergo revision surgery to proximal amputation due to healing complications.

Above Knee Amputation

Above Knee Amputation With Myodesis

Below Knee Amputation

Fore foot Amputation

 

The aftermath of amputation:

When catastrophes happen and patients lose a leg because of diabetic foot complications, then a storm of strong emotions, including fear and anger, is often aroused in patients and their relatives. They may seek a scapegoat someone to blame for the amputation as if apportioning

guilt makes them feel safer because they can then deny that a similar disaster could happen to the remaining leg. Unfortunately, it is often the last person who saw or treated the foot who is blamed for the catastrophe, and the sins they are accused of may be sins of commission or sins of omission.

When patients die after an amputation, their grieving relatives may similarly look for someone to blame. If patients and practitioners do not know each other well and treatments are not explained, problems of communication are more likely to develop. Because diabetic feet can go wrong with alarming rapidity and the triggering factors may not always be clear, practitioners are very vulnerable to criticism.

  • Wherever possible, practitioners should not attempt to treat high-risk diabetic foot patients in isolation
  • Full and careful record keeping is mandatory
  • When things are going badly, patients and their families should be forewarned.

 

Follow-up of the patient with diabetes having had a major amputation The long-term mortality from cardiovascular events is extremely high in these patients and many patients develop congestive cardiac failure, which needs aggressive management. Many of these patients have nephropathy, including some with end-stage renal failure who are on dialysis making them prone to peripheral oedema and electrolyte imbalance which need close attention. Cardiovascular risk factors also need marked consideration.