Infection in the Neuroischemic Foot

Creating a Practical Tool for Predicting Major Amputation Rate in Patients With Diabetic Hindfoot Ulcers: Focus on Ischemia and Infection

BACKGROUND

Patients with diabetic hindfoot ulcers typically harbor significant concerns regarding their prospects for healing or the potential for major amputation. Nonetheless, a scarcity of data addressing this prevalent and critical query exists. Thus, the aim of this study was to create an initial risk-scoring system to forecast the prognosis of individuals with diabetic hindfoot ulcers, leveraging assessments of ischemia and infection severity, which are recognized as the principal risk factors for amputation.

METHODS

Ischemia severity was categorized as iS0, iS1, or iS2 based on transcutaneous partial oxygen tension values, while infection severity was classified as iN0, iN1, or iN2 according to the results of tissue and bone biopsy cultures. Risk scores were determined by summing the scores for ischemia and infection severity, yielding a range of 0 to 4. Wound healing outcomes were graded as either healed with or without major amputation. Wound healing outcomes were assessed based on the assigned risk scores.

RESULTS

With ascending risk scores, the proportion of patients subjected to major amputation also increased (P value for trend < 0.001). Univariable logistic regression analysis revealed a significant positive correlation between escalating risk scores and major amputation incidence. Patients with a risk score of 4 exhibited a 41-fold higher likelihood of undergoing major amputation compared to those with a risk score of 0.

CONCLUSION

Risk scores can serve as a reliable predictor of the major amputation rate in patients with diabetic hindfoot ulcers.

Developing a Practical Tool for Predicting Wound Healing Outcomes of Patients with Diabetic Forefoot Ulcers: Focus on Vasculopathy and Infection

OBJECTIVE

To develop a preliminary risk scoring system to predict the prognosis of patients with diabetic forefoot ulcers based on the severity of vasculopathy and infection, which are the major risk factors for amputation.

METHODS

Forefoot was defined as the distal part of the foot composed of the metatarsal bones and phalanges and associated soft tissue structures. The degree of vasculopathy was graded as V0, V1, or V2 according to transcutaneous partial oxygen tension values and toe pressure. The degree of infection was graded as I0, I1, or I2 according to tissue and bone biopsy culture results. The risk scores were calculated by adding the scores for the degree of vasculopathy and infection and ranged from 0 to 4. Wound healing outcomes were graded as healed without amputation, minor amputation, or major amputation. The authors evaluated wound healing outcomes according to risk scores.

RESULTS

As the risk score increased, the proportion of patients who underwent both major and minor amputations increased (P < .001). In the multivariate logistic analysis, the odds ratios of amputation also increased as the risk score increased. Patients with a risk score of 4 were 75- and 19-fold more likely to undergo major and minor amputations, respectively, than patients with a risk score of 0 (P = .006 and P < .001).

CONCLUSIONS

The risk score can be used as an indicator to predict the probability of amputation in patients with diabetic forefoot ulcers.

Transcriptomic fingerprint of bacterial infection in lower extremity ulcers

Clinicians and researchers utilize subjective, clinical classification systems to stratify lower extremity ulcer infections for treatment and research. The purpose of this study was to examine whether these clinical classifications are reflected in the ulcer's transcriptome. RNA sequencing (RNA‐seq) was performed on biopsies from clinically infected lower extremity ulcers (n = 44). Resulting sequences were aligned to the host reference genome to create a transcriptome profile. Differential gene expression analysis and gene ontology (GO) enrichment analysis were performed between ulcer severities as well as between sample groups identified by k‐means clustering. Lastly, a support vector classifier was trained to estimate clinical infection score or k‐means cluster based on a subset of genes. Clinical infection severity did not explain the major sources of variability among the samples and samples with the same clinical classification demonstrated high inter‐sample variability. High proportions of bacterial RNA were identified in some samples, which resulted in a strong effect on transcription and increased expression of genes associated with immune response and inflammation. K‐means clustering identified two clusters of samples, one of which contained all of the samples with high levels of bacterial RNA. A support vector classifier identified a fingerprint of 20 genes, including immune‐associated genes such as CXCL8, GADD45B, and HILPDA, which accurately identified samples with signs of infection via cross‐validation. This study identified a unique, host‐transcriptome signature in the presence of infecting bacteria, often incongruent with clinical infection‐severity classifications. This suggests that stratification of infection status based on a transcriptomic fingerprint may be useful as an objective classification method to classify infection severity, as well as a tool for studying host–pathogen interactions.

Antimicrobial silver dressings: a review of emerging issues for modern wound care

Skin is an important barrier to pathogenic microorganisms and plays a critical role in a ctivation of innate immune responses. When the skin barrier is breached following wounding or burn injury, pathogens can invade and complicate healing with infection resulting in delayed healing and symptomatic scarring. Wound infection is a significant problem after burn injury and in patients with chronic wounds. Antimicrobial silver has had a significant role in wound antisepsis throughout history and, given the rise in community acquired antibiotic resistance, silver dressings are now commonly used to combat wound infection. The multi-modal mechanism of action, low potential for toxicity and formation of microbial resistance makes silver dressings suitable tools against a wide array of clinically important microbes. There are, however, a number of issues with silver dressings including a conflicting evidence base, the important environmental consideration of nanoparticle manufacture, and the significant cost of these products. One solution may be to adopt an 'opened-but-unused' means of wound care whereby bulk dressing materials are used piecemeal and stored in between dressing changes to increase the cost-effectiveness and reduced wastage. There is, however, little literature on this topic and so in vitro and clinical research must be performed to consider the efficacy of active ingredient dressings in wound care including silver dressings once opened and stored.

Staphylococcus aureus Toxins and Diabetic Foot Ulcers: Role in Pathogenesis and Interest in Diagnosis

Infection of foot ulcers is a common, often severe and costly complication in diabetes. Diabetic foot infections (DFI) are mainly polymicrobial, and Staphylococcus aureus is the most frequent pathogen isolated. The numerous virulence factors and toxins produced by S. aureus during an infection are well characterized. However, some particular features could be observed in DFI. The aim of this review is to describe the role of S. aureus in DFI and the implication of its toxins in the establishment of the infection. Studies on this issue have helped to distinguish two S. aureus populations in DFI: toxinogenic S. aureus strains (harboring exfoliatin-, EDIN-, PVL- or TSST-encoding genes) and non-toxinogenic strains. Toxinogenic strains are often present in infections with a more severe grade and systemic impact, whereas non-toxinogenic strains seem to remain localized in deep structures and bone involving diabetic foot osteomyelitis. Testing the virulence profile of bacteria seems to be a promising way to predict the behavior of S. aureus in the chronic wounds.

Systemic antibiotics for treating diabetic foot infections

BACKGROUND

Foot infection is the most common cause of non-traumatic amputation in people with diabetes. Most diabetic foot infections (DFIs) require systemic antibiotic therapy and the initial choice is usually empirical. Although there are many antibiotics available, uncertainty exists about which is the best for treating DFIs.

OBJECTIVES

To determine the effects and safety of systemic antibiotics in the treatment of DFIs compared with other systemic antibiotics, topical foot care or placebo.

SEARCH METHODS

In April 2015 we searched the Cochrane Wounds Group Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library); Ovid MEDLINE, Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE, and EBSCO CINAHL. We also searched in the Database of Abstracts of Reviews of Effects (DARE; The Cochrane Library), the Health Technology Assessment database (HTA; The Cochrane Library), the National Health Service Economic Evaluation Database (NHS-EED; The Cochrane Library), unpublished literature in OpenSIGLE and ProQuest Dissertations and on-going trials registers.

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating the effects of systemic antibiotics (oral or parenteral) in people with a DFI. Primary outcomes were clinical resolution of the infection, time to its resolution, complications and adverse effects.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, assessed the risk of bias, and extracted data. Risk ratios (RR) were estimated for dichotomous data and, when sufficient numbers of comparable trials were available, trials were pooled in a meta-analysis.

MAIN RESULTS

We included 20 trials with 3791 participants. Studies were heterogenous in study design, population, antibiotic regimens, and outcomes. We grouped the sixteen different antibiotic agents studied into six categories: 1) anti-pseudomonal penicillins (three trials); 2) broad-spectrum penicillins (one trial); 3) cephalosporins (two trials); 4) carbapenems (four trials); 5) fluoroquinolones (six trials); 6) other antibiotics (four trials).Only 9 of the 20 trials protected against detection bias with blinded outcome assessment. Only one-third of the trials provided enough information to enable a judgement about whether the randomisation sequence was adequately concealed. Eighteen out of 20 trials received funding from pharmaceutical industry-sponsors.The included studies reported the following findings for clinical resolution of infection: there is evidence from one large trial at low risk of bias that patients receiving ertapenem with or without vancomycin are more likely to have resolution of their foot infection than those receiving tigecycline (RR 0.92, 95% confidence interval (CI) 0.85 to 0.99; 955 participants). It is unclear if there is a difference in rates of clinical resolution of infection between: 1) two alternative anti-pseudomonal penicillins (one trial); 2) an anti-pseudomonal penicillin and a broad-spectrum penicillin (one trial) or a carbapenem (one trial); 3) a broad-spectrum penicillin and a second-generation cephalosporin (one trial); 4) cephalosporins and other beta-lactam antibiotics (two trials); 5) carbapenems and anti-pseudomonal penicillins or broad-spectrum penicillins (four trials); 6) fluoroquinolones and anti-pseudomonal penicillins (four trials) or broad-spectrum penicillins (two trials); 7) daptomycin and vancomycin (one trial); 8) linezolid and a combination of aminopenicillins and beta-lactamase inhibitors (one trial); and 9) clindamycin and cephalexin (one trial).Carbapenems combined with anti-pseudomonal agents produced fewer adverse effects than anti-pseudomonal penicillins (RR 0.27, 95% CI 0.09 to 0.84; 1 trial). An additional trial did not find significant differences in the rate of adverse events between a carbapenem alone and an anti-pseudomonal penicillin, but the rate of diarrhoea was lower for participants treated with a carbapenem (RR 0.58, 95% CI 0.36 to 0.93; 1 trial). Daptomycin produced fewer adverse effects than vancomycin or other semi-synthetic penicillins (RR 0.61, 95%CI 0.39 to 0.94; 1 trial). Linezolid produced more adverse effects than ampicillin-sulbactam (RR 2.66; 95% CI 1.49 to 4.73; 1 trial), as did tigecycline compared to ertapenem with or without vancomycin (RR 1.47, 95% CI 1.34 to 1.60; 1 trial). There was no evidence of a difference in safety for the other comparisons.

AUTHORS' CONCLUSIONS

The evidence for the relative effects of different systemic antibiotics for the treatment of foot infections in diabetes is very heterogeneous and generally at unclear or high risk of bias. Consequently it is not clear if any one systemic antibiotic treatment is better than others in resolving infection or in terms of safety. One non-inferiority trial suggested that ertapenem with or without vancomycin is more effective in achieving clinical resolution of infection than tigecycline. Otherwise the relative effects of different antibiotics are unclear. The quality of the evidence is low due to limitations in the design of the included trials and important differences between them in terms of the diversity of antibiotics assessed, duration of treatments, and time points at which outcomes were assessed. Any further studies in this area should have a blinded assessment of outcomes, use standardised criteria to classify severity of infection, define clear outcome measures, and establish the duration of treatment.

New Molecular Techniques to Study the Skin Microbiota of Diabetic Foot Ulcers

Significance: Diabetic foot ulcers (DFU) are a major and growing public health problem. They pose difficulties in clinical practice in both diagnosis and management. Bacterial interactions on the skin surface are important in the pathophysiology of DFU and may contribute to a delay in healing. Fully identifying bacteria present in these wounds is difficult with traditional culture methods. New molecular tools, however, have greatly contributed to our understanding of the role of the cutaneous microbiota in DFU. Recent Advances: Molecular technologies revealed new information concerning how bacteria are organized in DFU. This has led to the concept of "functionally equivalent pathogroups," meaning that certain bacterial species which are usually nonpathogenic (or at least incapable of maintaining a chronic infection on their own) may coaggregate symbiotically in a pathogenic biofilm and act synergistically to cause a chronic infection. The distribution of pathogens in multispecies biofilms is nonrandom. The high bacterial diversity is probably related to the development of a microbial biofilm that is irreversibly attached to the wound matrix. Critical Issues: Using molecular techniques requires a financial outlay for high-cost equipment. They are still too time-consuming to perform and reporting is too delayed for them to be used in routine practice. Finally, they do not differentiate live from dead or pathogenic from nonpathogenic microorganisms. Future Directions: Molecular tools have better documented the composition and organization of the skin flora. Further advances are required to elucidate which among the many bacteria in the DFU flora are likely to be pathogens, rather than colonizers.

2012 Infectious Diseases Society of America clinical practice guideline for the diagnosis and treatment of diabetic foot infections

Foot infections are a common and serious problem in persons with diabetes. Diabetic foot infections (DFIs) typically begin in a wound, most often a neuropathic ulceration. While all wounds are colonized with microorganisms, the presence of infection is defined by ≥2 classic findings of inflammation or purulence. Infections are then classified into mild (superficial and limited in size and depth), moderate (deeper or more extensive), or severe (accompanied by systemic signs or metabolic perturbations). This classification system, along with a vascular assessment, helps determine which patients should be hospitalized, which may require special imaging procedures or surgical interventions, and which will require amputation. Most DFIs are polymicrobial, with aerobic gram-positive cocci (GPC), and especially staphylococci, the most common causative organisms. Aerobic gram-negative bacilli are frequently copathogens in infections that are chronic or follow antibiotic treatment, and obligate anaerobes may be copathogens in ischemic or necrotic wounds. Wounds without evidence of soft tissue or bone infection do not require antibiotic therapy. For infected wounds, obtain a post-debridement specimen (preferably of tissue) for aerobic and anaerobic culture. Empiric antibiotic therapy can be narrowly targeted at GPC in many acutely infected patients, but those at risk for infection with antibiotic-resistant organisms or with chronic, previously treated, or severe infections usually require broader spectrum regimens. Imaging is helpful in most DFIs; plain radiographs may be sufficient, but magnetic resonance imaging is far more sensitive and specific. Osteomyelitis occurs in many diabetic patients with a foot wound and can be difficult to diagnose (optimally defined by bone culture and histology) and treat (often requiring surgical debridement or resection, and/or prolonged antibiotic therapy). Most DFIs require some surgical intervention, ranging from minor (debridement) to major (resection, amputation). Wounds must also be properly dressed and off-loaded of pressure, and patients need regular follow-up. An ischemic foot may require revascularization, and some nonresponding patients may benefit from selected adjunctive measures. Employing multidisciplinary foot teams improves outcomes. Clinicians and healthcare organizations should attempt to monitor, and thereby improve, their outcomes and processes in caring for DFIs.

Seminar Review: A Review of the Basis of Surgical Treatment of Diabetic Foot Infections

Infection is an extremely challenging complication of foot ulcers in patients with diabetes. Surgery as part of a multidisciplinary approach is key in the management of many types of diabetic foot infections (DFIs). Unfortunately, the surgical treatment of DFIs is based more on clinical judgment and less on structured evidence, which leaves unresolved doubts. The clinical presentation of DFIs is varied. This review examines the basis of nonvascular surgical treatment of DFIs, emphasizing the importance of the anatomic concepts of the foot, the variety of its clinical presentations, and the concepts of timing surgery. Recent evidence and case reports based on the author’s experience are presented in 2 parts. The first part examines clinical presentation of infections, whereas the second part deals with imaging, foot anatomy, and some case reports.

New insights in diabetic foot infection

Foot ulcers are common in diabetic patients, have a cumulative lifetime incidence rate as high as 25% and frequently become infected. The spread of infection to soft tissue and bone is a major causal factor for lower-limb amputation. For this reason, early diagnosis and appropriate treatment are essential, including treatment which is both local (of the foot) and systemic (metabolic), and this requires coordination by a multidisciplinary team. Optimal treatment also often involves extensive surgical debridement and management of the wound base, effective antibiotic therapy, consideration for revascularization and correction of metabolic abnormalities such as hyperglycemia. This article focuses on diagnosis and management of diabetic foot infections in the light of recently published data in order to help clinicians in identification, assessment and antibiotic therapy of diabetic foot infections.

Treatment of Diabetic Foot Osteomyelitis: A Surgical Critique

Osteomyelitis is one of the most frequent infections of the diabetic foot accounting for 10-15% of mild infections and almost 50% of severe infections. The definitive diagnosis of foot osteomyelitis requires obtaining bone samples for microbiological and histopathological studies. The treatment of osteomyelitis of the foot in diabetic patients continues to be debated. Until recently, most experts considered that the standard treatment for diabetic foot osteomyelitis should be the surgical removal of infected bone. Recent data suggest that antibiotic treatment can achieve an apparent remission of osteomyelitis though it is difficult to identify patients for this approach. One of the main arguments used to justify the solely antibiotic treatment of osteomyelitis is the alteration of foot biomechanics produced as a consequence of surgery. Conservative surgery combined with antibiotics is an attractive option in treating diabetic foot osteomyelitis because it may reduce the changes in the biomechanics of the foot and minimize the duration of antibiotic therapy. It is currently accepted that the combination of antibiotics with surgical removal of the infected bone may cure the majority of diabetic foot osteomyelitis. Recent literature emphasizes the role of antibiotics in the management of foot infections while little effort is dedicated to reviewing the surgical treatment of this challenging diabetic complication, apart from amputation. More research, including studies of adjunctive therapies in cases of bone infection in the feet of diabetic patients is required.

Diabetic foot infections: a team-oriented review of medical and surgical management

As the domestic and international incidence of diabetes and metabolic syndrome continues to rise, health care providers need to continue improving management of the long-term complications of the disease. Emergency department visits and hospital admissions for diabetic foot infections are increasingly commonplace, and a like-minded multidisciplinary team approach is needed to optimize patient care. Early recognition of severe infections, medical stabilization, appropriate antibiotic selection, early surgical intervention, and strategic plans for delayed reconstruction are crucial components of managing diabetic foot infections. The authors review initial medical and surgical management and staged surgical reconstruction of diabetic foot infections in the inpatient setting.

A stepwise approach to the surgical management of severe diabetic foot infections

Foot infections are common among diabetic patients with ulceration and are a major cause of hospitalization and lower extremity amputation. Aggressive and emergent surgical intervention is essential in the face of life- or limb-threatening infection to achieve limb salvage and survival. Critical limb ischemia, neuropathy, and an impaired host complicate the treatment of a severe diabetic foot infection. A severe diabetic foot infection carries a 25% risk of major amputation. For this reason, surgery should be coordinated with a well-functioning multidisciplinary team that specializes in diabetic limb preservation. Timing of surgery and strategies employed should be understood and agreed on by both the surgical and medical disciplines managing the diabetic patient with a limb-threatening infection. The overall strategy for surgically managing a severe diabetic foot infection is as follows: the first step is infection control through aggressive and extensive surgical debridement, the second step is a comprehensive vascular assessment with possible vascular surgery and/or endovascular intervention, and the final step is soft tissue and skeletal reconstruction after infection is eradicated to obtain wound closure and limb salvage. A consistent stepwise surgical approach combined with sound surgical principles is paramount for successful management of the severe diabetic foot infection. The authors discuss their stepwise surgical approach to reduce the mortality, morbidity, psychological distress, and length of hospitalization associated with life- or limb-threatening diabetic foot infections.

Surgical management of diabetic foot infections and amputations

The incidence of diabetes with severe foot infections (eg, necrotizing fasciitis, gas gangrene, ascending cellulitis, infection with systemic toxicity or metabolic instability) has risen significantly during the past decade. Foot infections are a major cause of hospitalization and subsequent lower extremity amputation among patients with diabetes mellitus who have a history of a preexisting ulceration. Surgical management often is required to address severe diabetic foot infections because they can be limb- or life-threatening. Critical limb ischemia, neuropathy, and an immunocompromised host, which often are associated with diabetic foot infections, complicate treatment and are associated with a poorer prognosis.

Plastic surgery reconstruction of the diabetic foot

Soft tissue reconstruction of the diabetic foot is a challenge for the perioperative team. Primary closure may not be an option and secondary healing may not be reliable. Therefore, surgery is vital and should be coordinated among a well-functioning multidisciplinary team that specializes in caring for patients with diabetes mellitus. Team members must have expertise in reconstructive surgery to ensure adequate wound healing. This article emphasizes the appropriate timing and staging of surgery, discusses the most common plastic surgery techniques, and underscores the importance of a team approach in the management of diabetic foot wounds.

A stepwise approach to the surgical management of severe diabetic foot infections

Foot infections are common among diabetic patients with ulceration and are a major cause of hospitalization and lower extremity amputation. Aggressive and emergent surgical intervention is essential in the face of life- or limb-threatening infection to achieve limb salvage and survival. Critical limb ischemia, neuropathy, and an impaired host complicate the treatment of a severe diabetic foot infection. A severe diabetic foot infection carries a 25% risk of major amputation. For this reason, surgery should be coordinated with a well-functioning multidisciplinary team that specializes in diabetic limb preservation. Timing of surgery and strategies employed should be understood and agreed on by both the surgical and medical disciplines managing the diabetic patient with a limb-threatening infection. The overall strategy for surgically managing a severe diabetic foot infection is as follows: the first step is infection control through aggressive and extensive surgical debridement, the second step is a comprehensive vascular assessment with possible vascular surgery and/or endovascular intervention, and the final step is soft tissue and skeletal reconstruction after infection is eradicated to obtain wound closure and limb salvage. A consistent stepwise surgical approach combined with sound surgical principles is paramount for successful management of the severe diabetic foot infection. The authors discuss their stepwise surgical approach to reduce the mortality, morbidity, psychological distress, and length of hospitalization associated with life- or limb-threatening diabetic foot infections.

Serum procalcitonin and C-reactive protein concentrations to distinguish mildly infected from non-infected diabetic foot ulcers: a pilot study

AIMS/HYPOTHESIS

Infection of diabetic foot ulcers is common; at early stages it is difficult to differentiate between non-infected ulcers (or those colonised with normal flora) and ulcers infected with virulent bacteria that lead to deterioration. This pilot study aimed to assess the diagnostic accuracy of inflammatory markers as an aid to making this distinction.

METHODS

We included 93 diabetic patients who had an episode of foot ulcer and had not received antibiotics during the 6 months preceding the study. Ulcers were classified as infected or uninfected, according to the Infectious Diseases Society of America-International Working Group on the Diabetic Foot classification. Diabetic patients without ulcers (n=102) served as controls. C-reactive protein (CRP), orosomucoid, haptoglobin and procalcitonin were measured together with white blood cell and neutrophil counts. The diagnostic performance of each marker, in combination (using logistic regression) or alone, was assessed.

RESULTS

As a single marker, CRP was the most informative for differentiating grade 1 from grade 2 ulcers (sensitivity 0.727, specificity 1.000, positive predictive value 1.000, negative predictive value 0.793) with an optimal cut-off value of 17 mg/l. In contrast, white blood cell and neutrophil counts were not predictive. The most relevant combination derived from the logistic regression was the association of CRP and procalcitonin (AUC 0.947), which resulted in a significantly more effective determination of ulcer grades, as shown by comparing receiver operating characteristic curves.

CONCLUSIONS/INTERPRETATION

Measurement of only two inflammatory markers, CRP and procalcitonin, might be of value for distinguishing between infected and non-infected foot ulcers in subgroups of diabetic patients, to help ensure the appropriate allocation of antibiotic treatment. Nevertheless, external validation of the diagnostic value of procalcitonin and CRP in diabetic foot ulcers is needed before routine use can be recommended.

The safety and efficacy of dressings with silver - addressing clinical concerns

With the increasing use of silver as a topical application in wound care, concerns focussing on its role are bound to arise. These concerns, which centre on issues such as resistance and toxicity, clinical efficacy and cost-effectiveness, need to be addressed and openly discussed so that they are viewed from a rational perspective. While clinical efficacy and safety, along with cost-benefit, are of obvious interest, the origin of some of these concerns is a matter of debate. The silver-containing dressing segment of the medical device market is of huge commercial importance, and, consequently, marketing and promotional issues occasionally obscure the evidence that clinicians need to have in order that they may provide appropriate treatment for their patients. The impact of silver application on the wound bioburden needs to be examined carefully to heighten our awareness of any deleterious effects on the healing process, without inducing any unfounded anxieties.

Emerging drugs for diabetic foot ulcers

Diabetic foot ulceration results from factors extrinsic to the foot such as repeated trauma, ischaemia and infection, as well as intrinsic factors that lead to impairment of wound healing. Intrinsic factors are less well understood, but include deficiency of growth factors, changes in extracellular matrix components with excess proteases, reduced fibroblast activity, cellular abnormalities, deficiencies of angiogenesis, nitric oxide abnormalities and hyperglycaemia. The scientific rationale of therapy is to correct both the external factors that cause diabetic foot ulcers and the internal factors that lead to impairment of wound healing. Current research is leading to new therapies that can be divided into the following classes: growth factors, skin substitutes, extracellular matrix proteins, stem cell therapy, gene therapy, protease inhibitors, angiogenesis stimulants, nitric oxide-releasing agents, adenosine agonists, immunostimulants, vasoactive compounds and granulating agents. These therapies should be considered when existing treatments to correct extrinsic factors have failed to heal ulceration in the diabetic foot.

Diabetic foot disorders. A clinical practice guideline (2006 revision)

The prevalence of diabetes mellitus is growing at epidemic proportions in the United States and worldwide. Most alarming is the steady increase in type 2 diabetes, especially among young and obese people. An estimated 7% of the US population has diabetes, and because of the increased longevity of this population, diabetes-associated complications are expected to rise in prevalence. Foot ulcerations, infections, Charcot neuroarthropathy, and peripheral arterial disease frequently result in gangrene and lower limb amputation. Consequently, foot disorders are leading causes of hospitalization for persons with diabetes and account for billion-dollar expenditures annually in the US. Although not all foot complications can be prevented, dramatic reductions in frequency have been achieved by taking a multidisciplinary approach to patient management. Using this concept, the authors present a clinical practice guideline for diabetic foot disorders based on currently available evidence, committee consensus, and current clinical practice. The pathophysiology and treatment of diabetic foot ulcers, infections, and the diabetic Charcot foot are reviewed. While these guidelines cannot and should not dictate the care of all affected patients, they provide evidence-based guidance for general patterns of practice. If these concepts are embraced and incorporated into patient management protocols, a major reduction in diabetic limb amputations is certainly an attainable goal.