Amputation Risk Factors and Prevention

Amputation refers to the surgical removal of a limb. It is usually carried out to remove ischemic, infected, or necrotic tissue, and helps prevent further tissue deterioration. The amputation rates in the United States due to diabetes and peripheral arterial disease have increased by about 27% in the last couple of decades which highlights the need for an effective amputation prevention strategy at a national level. [1] Given the growing incidence of diabetes mellitus globally and its associated complications, it is imperative for healthcare practitioners to educate the public about risk factors for more effective prevention of amputation.

Risk Factors For Amputation

To develop an effective amputation prevention strategy, it is important to be aware of the risk factors that can lead to lower-limb amputations. Following are the common risk factors associated with lower-limb amputations:

• Diabetes mellitus: A significant portion of all surgical lower-limb amputations in the United States are linked to diabetes. Compared to the normal population, diabetic individuals have a 15-46 times higher risk of undergoing an amputation in their lifetime. [2] This is because of ischemic and neuropathic changes observed in diabetes which make the lower limbs particularly vulnerable to the development of chronic, non-healing ulcers.
• Peripheral arterial disease: Peripheral arterial disease is a common cause of lower limb amputation, and can co-exist with diabetes. Amputation might be the only viable solution in patients for whom revascularization is not anatomically possible. However, the survival rate is considerably shortened due to critical limb ischemia and subsequent amputation. [3]
• Trauma: Motor vehicle accidents are a leading cause of crush injuries to the lower limbs. Significant tissue damage, neurovascular injury, and ischemia might make reconstructive procedures impossible. As a result, amputation is indicated to preserve the function of the remaining tissue. [4]
• Infection: Severe soft tissue and bone infection ("osteomyelitis") can affect the vessels in the lower limbs and lead to necrosis. Therefore, amputation becomes necessary to prevent the further spread of infection.
• Neoplasm: Tumors of the lower limb necessitate the removal of tissue to prevent the spread of cancerous cells. However, recent advances in limb-salvage techniques have made the need for amputation redundant. 

Diabetic Amputation Prevention

Given the grave amputation statistics linked with diabetes mellitus, the question of how to avoid amputation from diabetes is a very relevant one. Diabetic patients are at a higher risk of subsequent amputations due to the progressive nature of the disease. Compared to non-diabetics, they also are more likely to get amputated at a younger age, suffer more complications and die relatively early. [5] 85% of all amputations in the diabetic patients progress from diabetic foot ulceration. [6] Therefore, avoiding the development of foot ulcers is critical for the prevention of amputation in diabetic patients.

The following strategies can help in the reduction of diabetic foot ulceration and its consequent complications:

• Blood Sugar Control: There is evidence that good glycemic control limits the progression of diabetic polyneuropathy. As diabetic polyneuropathy is linked to unnoticed foot trauma and subsequent ulceration, effective glycemic control can lower the amputation rates in patients with diabetes. [7]
• Smoking Cessation: Smoking contributes to atherosclerosis and the development of peripheral arterial disease. Therefore, smoking cessation is recommended to avoid the progression to critical limb ischemia. 
• Regular Foot Inspection: Prompt recognition of foot ulcers can significantly reduce subsequent amputations. Therefore, patients with diabetes should be offered regular screening for calluses, skin changes, and ulcer formation in the foot and ankle region. Primary care physicians and podiatrists should also inform patients about the risk of unnoticed foot trauma.
• Patient Education: Patient education can play a vital role in the early detection of foot ulceration. Foot ulcers are primarily detected by relatives and health professionals which highlights a significant gap in patient awareness and knowledge regarding diabetic foot ulcers. [8] Efforts should be made to educate patients about the importance of self-inspection, regular foot care and wearing shoes designed specifically for diabetic patients. Effective patient education has been linked with better healing outcomes and a reduced need for surgical treatment. [9] Healthcare professionals should employ effective communication skills and should tailor their advice according to the patient's physical and psychological needs.
• Protective Shoes: Podiatrists should prescribe special, therapeutic 'diabetic' shoes to the patients. These shoes have been designed to reduce external pressure on the feet, and also prevent ulcer formation. These shoes can also “offload” the pressure from an existing foot ulcer. [10] 
• Multidisciplinary Approach: Diabetic foot ulcers are complex, and therefore, require a multidisciplinary management approach. Amputation prevention centers are equipped with the necessary equipment and multidisciplinary teams that can effectively handle the different aspects of diabetic foot care. Compared to conventional wound care centers, amputation prevention centers are dedicated to healing and reducing the rate of chronic wounds that can lead to amputation. Vascular surgeons, podiatrists, endocrinologists, general surgeons, and other wound care specialists provide specialized care to patients. The multidisciplinary management approach has been shown to significantly reduce the rates of amputation. [11]
• Vascular Interventions: Diabetic patients often have coexisting peripheral vascular disease. However, because of the lack of "rest" pain, they might not seek immediate medical attention. Vascular procedures like "percutaneous transluminal angioplasty" can help restore perfusion to the lower limbs. Complications associated with lower limb ischemia and amputation can therefore be avoided. Other limb salvage treatments can also help avoid amputations in diabetic patients. [12]
  

Conclusion

Amputations are psychologically distressing and life-altering for the patients. While an amputation might be a "necessary evil" in certain situations, it is always better to aim for preventive strategies. The best prosthetic limb device is never a substitute for a real limb. Therefore, there is a need for effective patient education and multidisciplinary management to reduce the rising rate of amputations.

References

1. Dillingham TR, Pezzin LE, MacKenzie EJ. Limb amputation and limb: epidemiology and recent trends in the United States. South Med J. 2002;95(8):875–83.
2. Reiber GE, Boyko EJ, Smith DG. Lower extremity foot ulcers and amputations in diabetes [Internet]. Nih.gov. [cited 2021 Nov 8]. Available from: https://www.niddk.nih.gov/-/media/Files/Strategic-Plans/Diabetes-in-America-2nd-Edition/chapter18.pdf
3. Sandnes DK, Sobel M, Flum DR. Survival after lower-extremity amputation. J Am Coll Surg. 2004;199(3):394–402.
4. Tintle SM, Agner Forsberg J, Keeling JJ, Shawen SB, Kyle Potter B. Lower extremity combat-related amputations. Journal of surgical orthopaedic advances. 2010 Jan 1;19(1):35.
5. Dillingham TR, Pezzin LE, Shore AD. Reamputation, mortality, and health care costs among persons with dysvascular lower-limb amputations. Archives of physical medicine and rehabilitation. 2005 Mar 1;86(3):480-6.
6. Larsson J, Stenström A, Apelqvist J, Agardh CD. Decreasing incidence of major amputation in diabetic patients: a consequence of a multidisciplinary foot care team approach?. Diabetic medicine. 1995 Sep;12(9):770-6.
7. Zilliox L, Russell JW. Treatment of diabetic sensory polyneuropathy. Current treatment options in neurology. 2011 Apr;13(2):143-59.
8. Macfarlane RM, Jeffcoate WJ. Factors contributing to the presentation of diabetic foot ulcers. Diabet Med. 1997;14(10):867–70.
9. Viswanathan V, Madhavan S, Rajasekar S, Chamukuttan S, Ambady R. Amputation prevention initiative in South India: positive impact of foot care education. Diabetes Care. 2005;28(5):1019–21.
10. Bus SA, van Deursen RWM, Kanade RV, Wissink M, Manning EA, van Baal JG, et al. Plantar pressure relief in the diabetic foot using forefoot offloading shoes. Gait Posture. 2009;29(4):618–22.
11. McCabe CJ, Stevenson RC, Dolan AM. Evaluation of a diabetic foot screening and protection programme. Diabet Med. 1998;15(1):80–4.
12. Panayiotopoulos YP, Tyrrell MR, Arnold FJ, Korzon-Burakowska A, Amiel SA, Taylor PR. Results and cost analysis of distal [crural/pedal] arterial revascularisation for limb salvage in diabetic and non-diabetic patients. Diabet Med. 1997;14(3):214–20.