Surgery for Diabetic Foot

A Practical Operative Manual

Aziz Nather

• Publisher: WSPC
• Year: 2016
• ISBN:
  9789814759854
• Topic: Medicina
• Subtopic: Ortopedia

This is the first textbook on surgery for Diabetic Foot in the world. It is written as a practical surgery manual for residents and young surgeons performing surgical procedures for patients with diabetic foot problems. Such a guide will be useful not only to residents and surgeons in Singapore but also to our neighbouring countries including, Malaysia, Indonesia, Hong Kong, India, Sri Lanka etc.

Each surgical procedure is written in a systematic fashion covering indications, pre-operative preparation, anaesthesia, patient positioning, operative technique (in step by step fashion and illustrations) and post-operative care.

The scope covers all aspects of surgery for diabetic foot from surgical debridement, split skin grafting, surgery for osteomyelitis, minor amputations including ray, transmetatarsal, Lisfranc, Chopart and Modified Pirogoff amputation to major amputations such as below knee, through knee and above knee amputation. It also includes assessment for revascularisation and revascularisation procedures.

This book will serve as a useful practical guide for training surgical residents and for surgeons aspiring to do diabetic foot surgery.

1

Diabetic Foot Wounds — Types of Wounds and Classification Systems

Aziz Nather and Tan Ting Fang

Introduction

Diabetes currently affects 387 million people globally, and it is expected to increase to 552 million by 2030¹ or one in ten adults (Fig. 1), owing to environmental factors such as sedentary lifestyles and changing dietary patterns. Ranked in the top ten leading causes of death in the world,³ diabetes has been considered as the “global epidemic of the 21^st century”.

Foot ulcers are very common in diabetic patients. It affects 15% of diabetic patients and precedes 84% of diabetic-related lower limb amputations.⁴ A diabetic patient is 40 times more likely to receive a lower limb amputation.⁴ Currently, it is estimated that for every 20 seconds, a leg is amputated due to diabetes worldwide.⁵

Lower limb amputations often cause mortality in diabetic patients: 70% of them die within five years after an amputation.⁴

Pathogenesis

It is necessary to first understand the pathogenesis of diabetic foot ulcers — the “Diabetic Foot Triad” (Fig. 2). The three risk factors — neuropathy, vasculopathy and immunopathy — contribute to varying degrees in different patients.

Figure 1. Diabetic foot triad

Table 1. Global prevalence of diabetes (2014 and 2030)

	2014	2030
Total world population (in billions)	7	8.3
Adult population (20–79 years, in billions)	4.4	5.6
Number of people with diabetes (in millions)	387	552
Global prevalence of diabetes (%)	8.3	9.9

In some patients, one component predominates (e.g. dry gangrene due to ischaemia), a combination of two risk factors may be responsible in others (e.g. wet gangrene due to ischaemia and infection). On the other hand, all three factors — neuropathy, ischaemia and infection — may be present in some patients.

Types of Wounds

Infective Wounds

Infective wounds are usually found on the dorsum of the foot or in the web space (Fig. 2).

Ischaemic Wounds

Ischaemic wounds result from diabetic vasculopathy (Fig. 3). Signs of chronic ischaemia are (1) shininess of the skin; (2) hair loss; (3) increased skin pigmentation; and (4) trophic nail changes. However, in most diabetic foot ulcers there is a degree of ischaemia, which is not severe enough to be apparent but promotes infection and causes delay in healing and increases risk of amputation.

Figure 2. Infective wounds

Figure 3. Ischaemic wounds

Both Infective and Ischaemic

Some wounds have features of both infection and ischaemia (Fig. 4).

Neuropathic Wounds

Neuropathic wounds usually occur in weight-bearing areas as a result of loss of protective sensation and high pressure points from changes in the mechanics of the foot (Fig. 5).

Figure 4. Both infection and ischaemia present

Figure 5. Neuropathic wounds

Decubitus Wounds

Decubitus wounds occur when too much pressure is constantly placed on the skin. Common sites include the heel, lateral malleolus and the lateral aspect of the 5^th metatarsal (Fig. 6).

Classification Systems

For this set of guidelines, we have adopted the Wagner-Meggitt Wound Classification^5,6 for classifying the wounds. In addition, the King’s College Classification⁷ is also used.

Wagner-Meggitt Wound Classification

This classification (Table 2 and Fig. 7) was first described by Meggitt in 1976⁵ and popularised by Wagner in 1981.⁶ It is a six-grade system that classifies ulcers according to the depth and extent of wound.

The advantages of the Wagner-Meggitt Wound Classification include its simplicity in usage and providing a guide for practitioners to plan the treatment...