Diabetic Foot Problems

The following sections are included:

• Dedication

• Contents

• List of Contributors

• Preface

• Introduction

Diabetes Mellitus (DM) is the fourth leading cause of death in most developed countries. The prevalence is fastest in developing countries — 75% of all diabetics in 2025. Hot spots include Middle East, Central America, Europe and South East Asia. The worldwide prevalence is estimated to increase from 4% in 1995 to 5.4% in 2025. India and China will make up one-third the total number of diabetics in the world by 2025. Death rate for DM has increased globally. Asians have developed a more thrifty gene compared to Westerners. Low birth weight may be prone to DM. Obese patients have higher incidence of DM. There is a trend for younger patients to develop DM with increased incidence of Type 2 DM in children, adolescents and young adults. Prevalence of DM in Nauru and Papua New Guinea with massive obesity is as high as 40%. Diabetes incur large health costs, consuming a large part of the health budget worldwide — due to both direct costs and indirect costs. The key to managing diabetic foot problems (DFP) is in its prevention. Once DFP has developed, a multi-disciplinary team approach is needed to best manage these complications effectively.

The socio-economic risk factors predisposing diabetics to foot problems were studied prospectively using two cohorts — one cohort consisting of 122 patients with diabetic foot problems (including cellulitis, abscess, osteomyelitis, septic arthritis, gangrene, ulcers and Charcot joint disease) and another cohort of 112 diabetics without foot problems seen in National University Hospital, from January to April 2007. A detailed protocol was designed. Factors studied included patient profile, education level, average monthly household income, compliance to diabetic medication, attendance at clinics for diabetic treatment, smoking, alcohol consumption, frequency of exercise and HbA1C level. Risk factors were determined by univariate and stepwise logistic regression analysis. Our results showed that with multivariate analysis, significant risk factors predisposing to diabetic foot problems were Malays (p < 0.001), education level of up to secondary school only (p = 0.021), low average monthly household income of less than S$2000 (US$1333) (p = 0.030), lack of weekly exercise (at least once a week, p = 0.04) and high HbA1C level (>7.0%, p = 0.015).

Diabetic Foot Problem (DFP) is a national problem requiring special consideration by the national health authority if we are to succeed in providing good health care and reduce the average length of stay, hospitalisation cost, major amputation rate and hospital re-admission rate for patients with DFP. The best way to do this is by using a multi-disciplinary approach to form a team including an orthopaedic surgeon, an endocrinologist an infectious disease specialist, a podiatrist, a vascular surgeon, specialist nurses and other allied health professionals. Such “foot teams” have been shown to ultimately reduce the major amputation rate. It is also strategic to implement a clinical pathway for DFP in addition to forming a “foot team”. The authors described the great success achieved by the formation of such a team and the implementation of an effective clinical pathway. The major amputation rate has been reduced from 31% in 2002 (before team formation) to 20% in 2004 (after team formation). The development of the National University Hospital (NUH) diabetic foot team not only provided better services for DFP in NUH but was also instrumental in starting a national as well as a regional movement for DFP. A national and regional association for DFP has been formed with the annual Asia Pacific Conference on Diabetic Limb Problem being held since 2004.

A multi-disciplinary, hospital-based diabetic foot clinic has been established at Kwong Wah Hospital since July 1995. The team was initiated by an orthopaedic surgeon and a podiatrist. It is mainly composed of orthopaedic surgeons, orthopaedic nurses, podiatrists and prosthetists/orthotists. Subsequently, a vascular surgeon and physician were also recruited. The clinic has successfully led to a 50% reduction of major lower extremity amputation.

This chapter covers the basic anatomy of the foot which must be understood in order to deal with diabetic foot problems. It includes surface anatomy, bones and joints, muscles, blood vessels and nerves of the foot. It also defines the motions of the ankle and foot including the complex movements of pronation and supination.

This chapter focuses on biomechanics of the foot in both the normal and the diabetic foot. The biomechanics of the foot in the normal gait cycle is discussed. Plantar pressure measurements in the foot including both platform and in-sole types of measurements to identify local areas of pressure in the foot are also described. Pathological changes in the diabetic foot lead to altered biomechanics in the foot different from that of the normal foot.

The high-risk diabetic foot is identified as the foot that has the potential to ulcerate. These feet can be identified by the presence of peripheral neuropathy, deformity, and previous ulceration. Early identification of the high-risk foot is important to prevent ulceration. Once an ulcer occurs the risk for potential lower extremity amputation is significantly higher. A good screening programme helps to achieve this and the high-risk patient can receive appropriate care and resources can be allocated.

Diabetic Foot Disease is a common cause for hospitalisation. It often is associated with increased mortality. A diabetic foot is complex in its pathogenesis and requires a multi-disciplinary team approach for effective management. When more professionals from different specialities are involved in its management, it is important to standardise the classification of diabetic foot disease. This ensures improved clinical outcomes. However, the diabetic foot is difficult to classify. Agood diabetic foot classification system must aim to identify major risk factors, provide guidelines for reducing variability in management, and improve communication amongst team members.

A patient with Diabetic Foot Problems must be examined systematically and comprehensively in order to make a diagnosis and render prompt treatment. A detailed history must be taken. A careful clinical examination must be done step by step. Instead of “look”, “feel”, “move” (the hallmark of orthopaedic examination for hip, knee, spine, etc.) the authors recommend a different approach.

• Inspection

• Examination for Immunopathy

• Examination for Vasculopathy

• Examination for Sensory Neuropathy

Basic essential investigations that must be performed after completing a proper clinical examination are outlined.

This chapter covers the definition of peripheral neuropathy and the available non-invasive neurological assessments performed. Peripheral neuropathy is subdivided into motor, sensory and autonomic neuropathy. Only assessments for motor and sensory neuropathy will be described. All assessments for testing motor nerves and sensory nerves are non-invasive, inexpensive and patient friendly. The assessments for testing motor nerves are position sense, Romberg test, two-point discrimination, deep tendon reflexes for lower limbs, coordination and muscle tone test. The assessments for testing sensory nerves are light touch test, pinprick test, Semmes-Weinstein monofilament test, biothesiometer, neurothesiometer test, tuning fork and temperature test. These assessments are crucial in identifying patients suffering from peripheral neuropathy. Not all tests are required to be performed. Doctors and practitioners may be selective in neurological assessment. Correct diagnosis of peripheral neuropathy helps early prevention for serious complications such as neuropathic ulcers in the foot. The frequency of performing neurological assessment varies depending on the patient's current condition. Nevertheless, it is recommended to conduct a full neurological assessment on the patient on an annual basis.

Vasculopathy is one of the main risk factors for diabetic foot complications along with neuropathy, foot deformity and infection. The prevalence of vasculopathy is 20-fold higher for diabetic patients and it accounts for more than 50% of lower extremity amputations. The vascular status of the diabetic foot can be difficult to assess by clinical examination alone. Non-invasive vascular tests are easy and fast to perform, inexpensive and has a reasonable reproducibility. They are essential for effective and early identification of vasculopathy.

Five hundred and fifty-seven patients who received diabetic foot screening services at the National University Hospital (NUH) from June 2006 to June 2007 were evaluated. A standardised protocol was used. All patients were classified according to King's classification. For neurological assessment, monofilament testing and biothesiometer testing were used. For vascular assessment, ankle brachial index (ABI), toe brachial index (TBI) and the presence or absence of palpable pulses inthe foot were used. The foot screening was performed by a trained assistant nurse. Majority of the patients were in the fifth (25.0%), sixth (26.7%) and seventh (25.0%) decades of life. The male:female ratio was 1.1:1; 524 had type II diabetes; and only 33 had type I diabetes. Theaverage duration of diabetes was 11.4 years. Hypertension (74.1%) was the most common co-morbidity followed by retinopathy (43.4%), IHD (35.4%), nephropathy (25.8%) and stroke (11.3%). Neuropathy was found in 225 (40.4%) patients based on 5.07 Semmes-Weinsteinmonofilament testing. Peripheral vascular disease (PVD) was recorded in 51 (4.6%) and 251 (22.5%) feet based on ABI < 0.8 and TBI < 0.7. Risk factors included hyperlipidaemia (67.1%) and smoking (11.5%). According to King's classification, 217 (39.0%) were Stage 1: Normal, 301 (54.0%) were Stage 2: High-Risk, 17 (4.8%) were Stage 3: Ulcerated, and 12 (2.2%) were Stage 4: Cellulitic. Foot screening is useful in the care of diabetic patients. Risk factors could be detected early for prompt referral to the relevant disciplines to prevent diabetic foot complications.

This chapter covers the statistical techniques using linear regression for quantitative outcomes, logistic regression for qualitative outcomes and Cox regression for time-to-event outcomes. Examples of result interpretation and presentation by means of tables for univariate and multivariate analyses were shown.

Control of blood sugar is a very important factor in the management of all diabetics. Medications are needed in addition to dietary restrictions and regular exercise. Type 1 and Type 2 diabetes are described — the most common being Type 2. The various types of medications prescribed are also elaborated. Capillary glucose monitoring and HbA1C monitoring are important for good diabetic management. Good glycaemic control prevents complications of diabetes from developing, including nephropathy, retinopathy, neuropathy and vasculopathy.

The epidemiology of diabetic foot infections and the predictive factors for limb loss were evaluated in a cohort of 100 diabetics treated at the National University Hospital (NUH) during the period January to June 2005. The mean age of study population was 59.8 years. Ethnically there was a significant increased representation in Malays along with a significant decreased representation in Chinese. All had type 2 diabetes. The common infections included abscess (32%), wet gangrene (29%) and infected ulcers (19%); 13 patients were treated conservatively. The major amputation rate (below and above knee amputations) was 28%; 48% had monomicrobial and 52% polymicrobial infections. The most common pathogens in both infectious were Staphylococcus aureus (39.7%), Bacteroides fragilis (30.3%), Pseudomonas aeroginosa (26.0%) and Streptococcus agalactiae (21.0%). Significant univariate predictivefactors for limb loss were ages about 60 years, gangrene, ABI < 0.8, monomicrobial infections, WBC ≥ 15.0 × 10⁹/L, ESR ≥ 100 mm/hr, CRP ≥ 15.0 mg/dL, Hb ≤ 10.0 g/dL and Cr ≥ 150 μmol/L. With stepwise logistic regression, only gangrene, ABI < 0.8, WBC ≥; 15.0 × 10⁹/L and Hb ≤ 10.0g/dL were significant.

Diabetic foot infections are a growing global problem. Good management of this disease entails a multi-disciplinary approach. Antibiotics play an important role in controlling the infection and stabilising patients who have systemic inflammatory response to the infection until definitive surgical therapy. Ensuring adequate blood supply and obtaining appropriate clinical microbiological samples are critical to successful antibiotic therapy of these infections. Empiric initial antibiotic choices should be guided by local microbiological data and as no single agent or combination of agents has been shown to be superior in randomised clinical trials, a variety of guidelines exist in different settings worldwide.

Necrotising fasciitis (NF) is one of the most dangerous conditions that could develop in a limb. Diabetes is the most common co-morbidity. Others include cancer, alcoholism and HIV. It presents as type I or polymicrobial NF and type II or monomicrobial infection or Group A Streptococcal NF. The pathology is a progressive rapidly spreading inflammatory infection in the deep fascia with secondary necrosis of subcutaneous tissues. Subcutaneous air is a classical feature clinically and radiologically. The patient is toxic and febrile with severe pain and tenderness, classical bullae formation and raised white blood cell count. It is important to make the diagnosis early. After fluid resuscitation and institution of antibiotics, the key to treatment is aggressive surgical debridement ahead of the advancing necrotic deep fascia. In cases where patients present late or condition is advanced, life could be saved by considering amputation of limb to remove the exceptionally high bacterial load and overwhelming toxicity. The mortality rate in NF can be as high as 25%. It is instrumental to have a high index of suspicion for diagnosis of this condition.

Outpatient parenteral antibiotic therapy (OPAT) is currently used for an increasing number of diabetic patients worldwide. It provided several potential advantages including quality of life, cost savings and reduced risk of hospital-acquired infections. Most commonly used access device is the peripherally inserted central catheter. The National University Hospital (NUH) has a hospital-based infusion centre which has recently expanded to provide outreach and caregiver delivered dosing. Blood samples are obtained at regular intervals to monitor laboratory values during the course of treatment. In setting up this OPAT service, senior ownership is very important and a nurse champion with intrinsic knowledge of local systems crucial and a team approach needed. Operations, finance, pharmacy, nursing administration are key stakeholders. OPAT helps diabetic patients return home safely and faster — thereby reducing hospital stay and costs, allowing better use of inpatient resources and restoring dignity and independence to our diabetic patients.

Major amputation resulting from a diabetic foot problem poses not only serious emotional burden but also serious mortality issues. Indeed amputation leads to loss of life. It is therefore imperative to avoid limb loss at all costs. This requires all diabetics to undergo annual foot screening and foot care to address the “foot at risk” promptly. Several research workers have studied the role of various factors as predictive factors for limb loss. The authors compare and discuss their results in evaluating predictive factors in a cohort of 202 diabetics with those of other co-workers.

With univariate analysis, predictive factors were found to be age above 60, co-morbidities like stroke and ischaemic heart disease, complications of diabetes including nephropathy, peripheral vascular disease and sensory neuropathy HbA1C level > 7%, ankle brachial index (ABI) < 0.8, foot problems such as gangrene and infection and pathogens such as MRSA and Staphylococcus aureus. With stepwise logistic regression, only peripheral vascular disease and infection were found to be significant.

Major lower limb amputation is the most dreadful complication of diabetic foot. A review on Hong Kong Chinese diabetics with ulcerated feet has identified ulcer depth, peripheral vascular insufficiency, old age and hypoalbuminemia to be factors associated with major amputation. An infected ulcer, neuropathy, anaemia and low lymphocyte count are frequently observed in this group of amputees. Amputation has a seasonal variation and is more commonly performed in summer. Establishing a dedicated clinic for this group of patients can lead to a dramatic decrease in amputation. Input from different disciplines is of vital importance to its success.

Local patients present with claudication or critical ischaemia; 80% of all patients with claudication are managed conservatively; 20% progress into critical ischaemia. Angioplasty is very useful for limb salvage for critical limb ischaemia. They have a high peri-procedure mortality rate which may be due to a selection bias (patients who are unfit for open bypass undergo angioplasty). There is a low peri-operative mortality trend for patients undergoing open revascularisation surgery (bias towards selecting “fit” patients to undergo bypass procedure). Peri-operative mortality for primary amputation and vascular reconstruction is almost similar. LEAP programme should be introduced to primary care physicians so that patients “at risk” are offered diabeticfoot screening early.

Major amputations — below knee amputation (BKA), above knee amputation (AKA), and through knee amputation (TKA) are the most dreaded complications of all diabetics presenting with diabetic foot problems. These amputations lead to a reduction in quality of life and impose a huge emotional burden on both the amputee and his family. Besides causing much morbidity, there is also high mortality risk involved with these amputations. The risk of mortality is about 10% during amputation and increases to 30% within one year, 50% within three years and 70% within five years. It therefore leads to loss of life, an important fact that is not well recognised or appreciated by both health care professionals and patients. These amputations must therefore be avoided by good preventive measures such as annual foot screening, good management of diabetes by a team approach, and an efficient clinical pathway when prevention fails.

It is therefore essential that when major amputations are performed, they must be done by diabetic surgeons well versed with the problems of diabetic limbs, the vascularity of the limbs and potential for tissue and wound healing in diabetics. Amputations performed on diabetics require special techniques quite different from amputations performed for trauma if the stump is to heal well. This chapter describes the special techniques for performing such major amputations in diabetes in detail.

Wherever possible, distal limb amputations should be performed to avoid major amputations such as below knee and above knee amputations. Distal limb amputations certainly give a better quality of life to the patient compared with major amputations. However, in order to succeed, the indications must be strictly followed. The vascularity of the foot must be good or the wounds will not heal. At least one foot pulse must be clinically palpable. This chapter describes the techniques of such operations which must be followed in meticulous detail. Operations described are ray amputation, transmetatarsal amputation and Syme's amputation.

This chapter covers the very important aspect of rehabilitation following lower limb amputation (below knee amputation: the most common major amputation performed). The objectives include pain control, wound care and control, contracture prevention and joint range of motion, physical conditioning and psychological support and education. Singapore's National University Hospital (NUH) Rehabilitation Programme for the Below Knee Amputee is described in detail. An important part of rehabilitation includes discharge planning and ultimately preparation of the stump for fitting of prosthesis.

After limb amputation a perception that the amputated limb is still there will always occur. It follows a specific pattern that is related with body image (Neuromatrix and Neurosignature theory by Melzack) called phantom limb sensation. Phantom limb pain is a different condition. It is highly variable, very individual and have a correlation with the experience of pain in the same limb before amputation. Phantom limb phenomenon is a continuing memory with or without pain of self-body perception or body image that is not there any more, modulated by neurohormones and neurotransmitters to reach homeostasis balance. The reactivation of pre-amputation pain memory (engram) is stronger in a diabetic limb amputee compared with a traumatic limb amputee because of longer pre-amputation pain experience. The prevention strategy of phantom pain in diabetics is very important. All steps must be taken to prevent this from happening, through good and careful management in the pre-amputation stage.

Charcot joint disease (CJD) or neuropathic joint is a progressive musculoskeletal condition that is characterised by severe damage and disruption of the joints and surrounding bones as a result of loss of sensation in the joint. It is a spectrum of diseases ranging from mild changes identifiable only on radiological examination to gross deformities of the foot easily detectable on both clinical and radiological examination. CJD can involve any joint. However, in the lower extremity, it occurs most commonly in the foot and ankle regions. The clinical phases of CJD — acute phase, bone destruction/deformity phase and stabilisation phase, and the investigations for CJD are discussed. The radiographic patterns/phases of CJD — fragmentation, coalescence and reconstruction phases are also presented. Finally, the chapter discusses the various classifications used for CJD ranging from Eichenholtz classification system to Brodsky's system (most widely used) and Saunders and Mrdjencovich anatomical classification system. The most common level of involvement are in Lisfranc's tarsometatarsal joints (40%) and in the intertarsal joints (30%) — naviculocuneiform, talonavicular and calcaneocuboid joints.

Charcot joint disease (CJD) or neuropathic joint of the foot is a spectrum of disease ranging from mild changes that can only be identified on radiological examination to gross deformities of the foot that are easily detected on both clinical and radiological examination. The pathology starts from the loss of protective sensation which leads to gradual damage and disruption of the joints and surrounding bones. Early diagnosis and treatment is critical to a successful outcome. Treatment of CJD is primarily non-operative. Treatment consists of two phases: an acute phase treated by immobilisation and reduction of stress, and a post-acute phase treated by wearing custom-made footwear which offers protection and support including total contact casting, modified ankle foot arthoses (AFOs), pneumatic walking brace and bivalved cast. Biphosphonates have been recently advocated. Operative treatment is indicated when there is symptom of instability or a deep-seated infection as a complication of neuropathic ulcers. It includes mid-foot fusions, hind-foot fusions, triple arthrodesis, sub-talar joint fusions and ankle fusions. A-frame external fixation for ankle fusion has been shown to give encouraging results. Others prefer using retrograde (intra-medullary) femoral nail (size 9) with interlocking screws.

An understanding of the principles of wound healing is essential for all medical staff involved in the treatment of wounds. Recent advances have given us an insight into the complexity of the underlying cellular processes that control and regulate this process of wound healing. Despite this, our understanding is superficial and incomplete. This chapter provides an introduction to the principles of wound healing, reviews the effect of diabetes mellitus on wound healing and suggests strategies to improve wound healing.

In the treatment of wound, a good understanding of the principles of wound healing is essential. A moist wound healing environment is needed. A range of new generation dressings has emerged in addition to traditional dressings such as gauze and tulle gras. These include low-adhesive dressings, transparent dressings, hydrocolloids, hydrogels, alginates, foams, hydrofibres, anti-microbial dressings, de-odouriser dressings and collagen dressings. The choice of dressing depends on a proper assessment of the wound (presence of ischaemia, infection, etc.) and matching the properties of the various dressings available to best meet the individual needs of that particular wound.

Each diabetic wound has its own characteristics (ischaemic, infective, neuropathic, etc.) which must be studied carefully to decide on what type of treatment or dressing is required. In the last decade, a large variety of new generation dressings using the latest technology has appeared on the market. These include hydrogels and hydrocolloids, alginates and aquacel hydrofibre dressings, foams and anti-microbial dressings, soft silicone dressings, moisture retentive dressings and silver sulphadiazine dressings. The wound product specialists from the private sector now has an important role to play in the healing of diabetic wounds. The health care professionals treating the wounds now have a wider range of products to choose from. Each wound must be evaluated to choose the appropriate dressing to best meet the individual needs of that wound.

Monochromatic infrared energy (MIRE) or anodyne therapy has been shown to increase nitric oxide level locally and increase the local circulation at the site it is applied. Diabetic foot ulcers may take a long time to heal. Chronic diabetic foot ulcers resistant to conventional treatment with daily dressings could be treated with anodyne therapy on an outpatient basis. The authors showed successful application of their modality of treatment in four chronic diabetic foot ulcers which failed to heal with conventional methods.

Necrotic diabetic foot ulcers present with necrotic and non-viable tissue that impairs the normal wound healing process. Frequent debridement is required to clear the wound of non-viable tissue. Low-frequency ultrasound is a form of mechanical debridement by way of cavitation and acoustic streaming effects. Fibrin deposits and bacteria are flushed out and cellular activities important for wound healing are stimulated. Ultrasonic debridement provides a mechanical solution for the management of patients that are at risk of amputation. It has been found to be effective in the debridement of dirty chronic diabetic wounds and is especially useful when the patients are too ill for surgical debridement.

Chronic diabetic foot ulcers are sometimes resistant to conventional treatment with debridements and daily dressings. Extracorporeal shockwave therapy (ESWT) by stimulating angiogenesis locally could accelerate tissue healing. Schaden et al. first reported treating skin lesions with ESWT with a study cohort of 102 patients (104 chronic foot ulcers). They found 74% efficacy of success to produce complete healing. No adverse effect was observed. This cohort did not include any chronic diabetic ulcer. Schaden et al. further reported on the treatment of 175 patients (177 chronic skin lesions) with 74.5% showing complete healing. Santos et al. reported 12 case reports of chronic skin lesions treated by ESWT, four being diabetic foot lesions. They concluded that ESWT was effective, although it is noted that their study size was small. Currently, a randomised control study is underway by United States National Institute of Health by Tissue Regeneration Technologies since August 2006 to study the safety and efficacy of ESWT using Dermagold® for the treatment of chronic diabetic plantar foot ulcers. The authors are also currently conducting a randomised control study on the efficacy of ESWT for the treatment of chronic diabetic dorsal foot ulcers in collaboration with Dornier Medtech. A phase I/II FDA-sponsored diabetic foot ulcer study in the US is also currently underway by Attinger and Steinberg at the Limb Centre, Georgetown University.

Diabetic foot ulceration is a significant and growing problem that has a high morbidity and is demanding on health care resources. It is expected to account for 25% of the costs of treating diabetes. Successful treatment of this problem requires a multi-disciplinary approach that addresses the aetiological factors of peripheral neuropathy, infection and peripheral vascular disease. VAC therapy can feature as an adjunct in this management as it improves the local condition for healing, however, it can only be useful if the patient is systemically optimised and in the anabolic phase for healing.

Diabetic foot care education and diabetic foot screening are essential for all diabetic patients. One of the major complications in diabetes is foot ulceration due to poor vascular status, nerve damage and lack of self-foot care. Patients should follow-up on a six-month or yearly checkup with diabetic foot care nurses. The physical examination and testing results are useful for the physician when considering the state of the patient's feet condition. Diabetic foot care education plays an important role in the care of the patient's feet. Diabetic foot care nurses are trained and qualified to conduct foot screening and provide education sessions to patients. Educational resources are used in assisting patient's understanding in self-foot care. Places such as hospitals, polyclinics and national foot care centres provide diabetic foot screening and foot care services to all diabetic patients. The aim is to achieve an effective and structured foot care education in order to improve treatment outcome and prevent recurrence of the foot problem. According to the National Institute for Health and Clinical Excellence (NICE) guideline, “education is an essential element in the empowerment of people with diabetes”.

Diabetic footwear plays an important role in the prevention of diabetic foot problems. Recommended guidelines for the design of therapeutic diabetic footwear are discussed. The role of in-shoe pedobarograph system for therapeutic footwear is described. The problems of footwear in the elderly especially poor fitting of shoes and compliance are highlighted. A major problem is the rejection of footwear due to cultural, aesthetic and costs reasons. Pendsey's four risk categories and recommendations for appropriate footwear are described. Most diabetics buy footwear from the general shoe market especially risk category 0 (no neuropathy). For categories 1 and 2, shoes (outdoors) and sandals (indoors) are recommended. Majority of our clients prefer sandals outdoors and walk barefeet at home. The authors advocate the design, fashion and fabrication of shoes (for outdoors) with male and female design and sandals (indoors) to meet the aesthetic and cultural requirements in line with the needs of our culture. For diabetics with special needs, therapeutic sandals, custom-made insoles and custom-made shoes need to be designed. In the near future, the development of a Diabetic Footwear Centre in Singapore's National University Hospital (NUH) to fashion, design and manufacture diabetic footwear that is not only preventive, protective and therapeutic but also aesthetic, low cost and culturally acceptable will go a long way to serve all diabetics not only in NUH but in all hospitals in Singapore with potential to collaborate with diabetic footcare services in all countries in the region.

Most diabetic footwear originate from Europe and the United States with temperate climates and with different cultural footwear habits compared to South East Asia and Asia with tropical climates. There are three main types of shoes — healing sandals/post-operative shoes, standard street shoes and walking shoes. In Singapore, running shoes have been the shoe of choice for recommendation. Eighty per cent of our population do not find shoes acceptable and use sandals instead even for outdoor use. There is a great need to design and fashion diabetic shoes (for outdoor use), sandals (for indoor use) and therapeutic sandals (for diabetics wih special needs) that is culturally acceptable by our local population.

This study evaluates the type of footwear worn by 100 diabetics indoors and outdoors. Forty-two had no foot complications (King's 1 and 2); 58 had diabetic foot complications (King's 3 to 6); 54% did not wear footwear at home whilst 38% used slippers. All patients used footwear outdoors with 49% wearing shoes 26% slippers and 25% sandals. Leather footwear was used outdoors by 51 patients. Majority of outdoor footwear did not have fixation and removable insoles. Only 11 and 51 patients used socks indoors and outdoors, respectively.

Proper footwear is an indispensable component of a successful diabetic foot care programme. Active Charcot arthropathy needs total contact cast. However, this modality is not welcomed by patients due to the tropical climate. Patients with foot ulcer are mostly dispensed with a half-shoe or wedge-type shoe for off-loading. A pair of quality athlete shoes might suffice for most diabetes. Majority of high-risk diabetic feet can be settled with off-the-shelf orthotic shoes and a custom-made insole. In uncommon scenarios, complex deformity warrants custommade orthotic shoe. Although designing and prescribing therapeutic footwear is largely an art, it has now gradually evolved into a science. A large area in this terrain demands further clinical research and biomechanical study.

The following sections are included:

• Index