Introduction Diabetic foot as defined by the World Health Organization is, ‘The foot of a diabetic patient that has the potential risk of pathologic consequences, including infection, ulceration, and/ or destruction of deep tissues associated with neurologic abnormalities, various degrees of peripheral vascular disease, and/or metabolic complications of diabetes in the lower limb’.

Epidemiology of diabetic foot disorders

Diabetes is one of the causes of mortality worldwide and is a leading cause of morbidities like blindness, renal failure, and nontraumatic amputations. One of the most common complications of diabetes in the lower extremity is the diabetic foot ulcer. As estimated, 15% of patients with diabetes will develop a lower extremity ulcer during the course of the disease. Around 7–20% of patients with foot ulcers will subsequently require amputation; foot ulceration is the precursor to approximately 85% of the lower extremity of amputations in persons with diabetes. There is a 50% incidence of the serious contralateral lesion following lower extremity amputations (LEAs), and a 50% incidence of contralateral amputation within 2–5 years of an LEA.

Risk for foot ulceration
Foot ulceration is the most common single precursor for LEA seen among diabetic patients. Risk factors include peripheral neuropathy, vascular disease, limited joint mobility, foot deformities, abnormal foot pressures, minor trauma, a history of ulceration or amputation, and impaired visual acuity. The other contributing factors include Poor vision, limited joint mobility, cerebrovascular disease, peripheral edema, impaired healing, impaired fibroblast function, deficiency in growth factors, abnormalities of the extracellular matrix. The best predictor of amputation is a history of the previous amputation. Re-amputation can attribute to the progression of the disease process, non-healing ulcer, and development of additional risk factors for limb loss.
Evaluation and management
The evaluation of the diabetic foot involves careful history and physical examination.
 

History needs to be comprehensive and must cover general, medical, Surgical (including ulcers, disarticulation, amputation, vascular or orthopedic intervention), drug and allergies history. Specifi c to the foot, neuropathic vs ischemic pain, daily activities & use, callus formation, deformities, skin & nail changes needs to be documented.

All patients with diabetes require proper foot inspection, and a thorough foot examination should be performed at least once each year. Patients with diabetic foot-related complaints will require detailed evaluations more frequently. Examination of both feet should be performed systematically from dorsum, plantar, lateral border, medial border, back of the heel, interdigital areas and malleoli. A comprehensive assessment of vascular system, neurological system, skin and integumentary system, musculoskeletal system and Footwear examination is critical in managing diabetic foots.

Stage 1 — Normal foot
Stage 2 — High-risk foot
Stage 3 — Ulcerated foot
Stage 4 — Infected foot
Stage 5 — Necrotic foot
Stage 6 — Unsalvageable foot

Treatment of DFU is comprehensive multimodality team approach with each team member interested and experienced in treating DFUs. The primary goal in the treatment of DFU is to obtain wound healing as soon as possible. The resolution of foot ulcers and decreasing the rate of recurrence can lower the probability of LEA in the diabetic patient. Frequent re-evaluation with response-directed treatment is essential. Once healed, the management consists of decreasing the probability of recurrence. Some of the essential therapeutic objectives include debridement, pressure relief (off-loading), appropriate wound management, management of infection, management of ischemia, medical management of co-morbidities and surgical management.

Debridement
Adequate debridement must always precede the application of topical wound healing agents, dressings, or wound closure procedures. The only method which has been proven effi cacious in clinical trials is surgical debridement and is a key component and a cornerstone in the management of DFU. Excision of necrotic tissue extends as deeply and proximally as necessary until healthy, bleeding soft tissue and bone are encountered. Any callus tissue surrounding the ulcer must also be removed. Joint resection or partial amputation of the foot is needed in the presence of osteomyelitis, joint infection, or gangrene. Necrotic tissue removed on a regular basis can expedite the rate at which a wound heals and has been shown in a recent study to increase the probability of attaining full secondary closure.
 
Outcomes

The goals of treating a diabetic foot infection are the eradication of clinical evidence of infection and the avoidance of soft tissue loss and amputations. Overall good clinical response which may be resolution of clinical evidence of infection to appropriate therapy is achieved in 80–90% of mild-to-moderate infections and in 60–80% of severe infections. Factors associated with a poor outcome include signs of systemic infection, inadequate limb perfusion, osteomyelitis, the presence of necrosis or gangrene, an inexperienced surgeon and proximal location of the infection.

Prevention

Detection of neuropathy before its complications ensue is the best method to prevent foot infections. Educate the patient about the importance of optimizing glycemic control, using appropriate footwear at all times, avoiding foot trauma, performing daily selfexamination of the feet, and reporting any changes to healthcare professionals.

Who should be referred?

Refer the following to a multidisciplinary team within 24 hours: New ulceration (wound), new swelling, new discoloration (redder, bluer, paler, blacker, over all or part of the foot), signs or symptoms of infection (redness, pain, swelling, or discharge) and deep ulcer