Severity of diabetic foot infection and rate of limb salvage

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.

Exploring the Relationship Between SVS WIfI and IWGDF Scoring Systems and Reamputation Risk in Patients With Diabetic Foot and Peripheral Artery Disease

Determining the optimal amputation level in diabetic foot (DF) and peripheral artery disease (PAD) patients is crucial for minimizing reamputation risk while preserving functionality. The Society for Vascular Surgery Wound, Ischemia, and Foot Infection (SVS WIfI) and International Working Group on Diabetic Foot (IWGDF) scoring systems are widely used for risk stratification, but their predictive value for reamputation remains unclear. The current study aimed to evaluate the predictive utility of these scoring systems for reamputation risk in patients undergoing amputations due to DF or PAD. A retrospective cohort study was conducted on 108 patients who underwent unilateral amputations due to DF or PAD between 2016 and 2021. Patients were categorized based on WIfI and IWGDF classifications, and clinical outcomes, including reamputation rates, ICU admissions, and mortality, were analyzed using logistic regression and post hoc analyses. Reamputation occurred in 41 (38%) patients. Higher WIfI (OR: 3.85, 95% CI: 2.10-7.05, P = .001) and severe IWGDF scores (OR: 3.25, 95% CI: 1.80-5.88, P = .008) significantly correlated with increased reamputation risk. Patients with high-risk scores also exhibited higher ICU admission (P = .03) and mortality rates (P = .01). Male gender (OR: 3.47, 95% CI: 1.45-8.31, P = .005), diabetes (OR: 2.32, 95% CI: 1.10-4.90, P = .027), and prolonged hospitalization (OR: 1.04, 95% CI: 1.01-1.08, P = .021) were independent predictors, while above-ankle amputations were protective for reamputation (OR: 0.22, 95% CI: 0.11-0.43, P < .001). Both scoring systems are effective in predicting reamputation risk, with WIfI providing a more comprehensive risk assessment. Combining these tools may enhance decision-making and improve patient outcomes in terms of reamputation prevention, hospital stay, ICU admission, and mortality.

Duration of Antibiotic Treatment for Foot Osteomyelitis in People with Diabetes

Background: The optimal antimicrobial treatment duration for diabetes-related foot osteomyelitis (DFO) currently needs to be determined. We systematically reviewed the effects of short and long treatment durations on outcomes of DFO. Methods: We performed a systematic review searching Cochrane, CENTRAL, MEDLINE, Embase, and CINAHL Plus from inception up to 19 January 2024. Two independent reviewers screened the titles and abstracts of the studies. Studies comparing short (<6 weeks) and long (>6 weeks) treatment durations for DFO were included. The primary outcome was amputation; the secondary outcomes were remission, mortality, costs, quality of life, and adverse events. Risk of bias and GRADE were assessed. Results: We identified 2708 references, of which 2173 remained after removing duplicates. Two studies were included. Differences in methodology precluded a meta-analysis. The primary outcome, major amputation, was reported in one study, with a rate of 10% in both the intervention and comparison groups (p = 1.00), regardless of treatment duration. For the secondary outcome, remission rates, the first study reported 60% in the intervention group versus 70% in the comparison group (p = 0.50). In the second study, remission rates were 84% in the intervention group versus 78% in the comparison group (p = 0.55). Data for the outcomes mortality, costs, and quality of life were not available. Short treatment duration may lead to fewer adverse events. The risk of bias was assessed as low to moderate, and the level of evidence ranged from very low to moderate. Conclusions: Our findings suggest that for DFO, there is no difference between a shorter and more prolonged duration of antimicrobial treatment regarding amputation and remission, with potentially fewer adverse events with shorter treatment durations. However, the uncertainty stems from limited, heterogeneous studies and generally low-quality evidence marred by moderate biases, imprecision, and indirectness. More high-quality studies are needed to substantiate these findings.

Residual diabetic foot osteomyelitis after surgery leads to poor clinical outcomes: A systematic review and meta-analysis

The aim of this meta-analysis is to compare the clinical outcomes in patients with and without residual osteomyelitis (ROM) after surgical bone resection for diabetic foot osteomyelitis (DFO). We completed a systematic literature search using PubMed, Scopus, and Embase using keywords DFO, Residual OM (ROM), and positive bone margins. The study outcomes included wound healing, antibiotic duration, amputation, and re-infection. Five hundred and thirty patients were included in the analysis; 319 had no residual osteomyelitis (NROM), and 211 had ROM. There was not a significant difference in the proportion of wounds that healed 0.6 (p = 0.1, 95% confidence intervals [95% CI] 0.3-1.3). The risk of infection was 2.0 times higher (OR = 2.0, p = 0.02, 95% CI 1.1-3.4), and the risk of amputation was 4.3 times higher (OR = 4.3, p = 0.0001, 95% CI 2.4-7.6) in patients with ROM. Patients with ROM received antibiotics significantly longer. The mean difference was 16.3 days (p = 0.02, 95% CI 11.1-21.1).

Risk factors related to amputation in diabetic foot patients: single center outcomes

AIM

This study aimed at identifying factors that worsen the prognosis of diabetic foot, one of the most common complications seen in patients with diabetes.

Perioperative Risk Factors for Early Major Amputation Following First-Time Diabetic Forefoot Amputation

BACKGROUND

Despite a meticulous multidisciplinary team approach, limb salvage remains uncertain even after the initial forefoot amputation in patients with end-stage diabetes. Which of many factors strongly influence the early failure of the limb salvage strategy remains unknown. This study aimed to analyze perioperative independent risk factors for major amputation within 1 year following first-time diabetic forefoot amputation.

METHODS

Perioperative variables of 808 diabetic forefoot amputations performed in a tertiary referral center specialized for organ transplantation and end-stage diabetes were analyzed. Major amputations were performed in 104 patients (12.9%) throughout follow-up, and 77 (74%) of 104 patients had their major amputation within 1 year. Cox proportional hazards were examined to assess the risk factors for major amputation performed within 1 year.

RESULTS

In univariate analysis, 18 possible risk factors significantly differed between patients with and without early major amputation. In stepwise multivariable analysis, chronic renal failure (CRF), peritoneal dialysis, and bilateral initial amputation were strong risk factors for early major amputation, with hazard ratios of 2.973 (95% CI 1.805-4.896, P < .0001), 2.558 (95% CI 1.113-5.881, P = .027), and 2.515 (95% CI 1.318-4.798, P = .005), respectively.

CONCLUSION

Regardless of kidney transplantation (KT) status, CRF strongly predicts >20% chance of major amputation within 1 year after the first diabetic forefoot amputation.

Life expectancy of patients with diabetic foot sepsis post-lower extremity amputation at a regional hospital in a South African setting. A retrospective cohort study

BACKGROUND

Diabetes foot sepsis (DFS) is the leading cause of amputation of lower extremities. Over 50 % of patients who have had major lower extremity amputation due to DFS are dead within 4 years following the procedure.

AIM

To determine the life expectancy of patients following amputation for DFS at a regional hospital in South Africa.

METHODS

We conducted an audit of patients who had DFS and were admitted over a 5-year period. The duration from admission to time of death was recorded in days. Occurrence of death was confirmed from family members of the deceased using structured telephonic interview questionnaires. Categorical findings were summarized using actual counts and percentages and compared using either the Chi-square or Fisher's exact test. We used the mean with standard deviation or median and range to compare parametric and non-parametric continuous data, respectively. The Shapiro-Wilk test was used to test normality of data. Multivariate logistic regression was done to establish factors that were strongly associated with the mortalities. Adjusted survival curves were added to compare the rate of occurrence of mortality between males and females with age as a confounder. Statistical significance was set at a p-value below 0.05.

RESULTS

197 were found of which 100 % of participants had Type 2 diabetes mellitus and 63.5 % were males. Associated comorbidities included hypertension in 73.6 %, obesity in 66 %, alcohol use in 64.5 % and smoking in 58.4 %. 190 participants had an amputation and 19.3 % died.

CONCLUSION

DFS was more common in males and 96 % of the patients had an amputation. Mortality rate within 4 years following amputation was 19.3 % and was higher in females and individuals with multiple comorbidities.

Diagnosis of infection in the foot of patients with diabetes: A systematic review

BACKGROUND

Securing an early accurate diagnosis of diabetic foot infections and assessment of their severity are of paramount importance since these infections can cause great morbidity and potential mortality and present formidable challenges in surgical and antimicrobial treatment.

METHODS

In June 2022, we searched the literature using PubMed and EMBASE for published studies on the diagnosis of diabetic foot infection (DFI). On the basis of pre-determined criteria, we reviewed prospective controlled, as well as non-controlled, studies in English. We then developed evidence statements based on the included papers.

RESULTS

We selected a total of 64 papers that met our inclusion criteria. The certainty of the majority of the evidence statements was low because of the weak methodology of nearly all of the studies. The available data suggest that diagnosing diabetic foot infections on the basis of clinical signs and symptoms and classified according to the International Working Group of the Diabetic Foot/Infectious Diseases Society of America scheme correlates with the patient's likelihood of the need for hospitalisation, lower extremity amputation, and risk of death. Elevated levels of selected serum inflammatory markers such as erythrocyte sedimentation rate (ESR), C-reactive protein and procalcitonin are supportive, but not diagnostic, of soft tissue infection. Culturing tissue samples of soft tissues or bone, when care is taken to avoid contamination, provides more accurate microbiological information than culturing superficial (swab) samples. Although non-culture techniques, especially next-generation sequencing, are likely to identify more bacteria from tissue samples including bone than standard cultures, no studies have established a significant impact on the management of patients with DFIs. In patients with suspected diabetic foot osteomyelitis, the combination of a positive probe-to-bone test and elevated ESR supports this diagnosis. Plain X-ray remains the first-line imaging examination when there is suspicion of diabetic foot osteomyelitis (DFO), but advanced imaging methods including magnetic resonance imaging (MRI) and nuclear imaging when MRI is not feasible help in cases when either the diagnosis or the localisation of infection is uncertain. Intra-operative or non-per-wound percutaneous biopsy is the best method to accurately identify bone pathogens in case of a suspicion of a DFO. Bedside percutaneous biopsies are effective and safe and are an option to obtain bone culture data when conventional (i.e. surgical or radiological) procedures are not feasible.

CONCLUSIONS

The results of this systematic review of the diagnosis of diabetic foot infections provide some guidance for clinicians, but there is still a need for more prospective controlled studies of high quality.

IWGDF/IDSA guidelines on the diagnosis and treatment of diabetes-related foot infections (IWGDF/IDSA 2023)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the management and prevention of diabetes-related foot diseases since 1999. The present guideline is an update of the 2019 IWGDF guideline on the diagnosis and management of foot infections in persons with diabetes mellitus. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework was used for the development of this guideline. This was structured around identifying clinically relevant questions in the P(A)ICO format, determining patient-important outcomes, systematically reviewing the evidence, assessing the certainty of the evidence, and finally moving from evidence to the recommendation. This guideline was developed for healthcare professionals involved in diabetes-related foot care to inform clinical care around patient-important outcomes. Two systematic reviews from 2019 were updated to inform this guideline, and a total of 149 studies (62 new) meeting inclusion criteria were identified from the updated search and incorporated in this guideline. Updated recommendations are derived from these systematic reviews, and best practice statements made where evidence was not available. Evidence was weighed in light of benefits and harms to arrive at a recommendation. The certainty of the evidence for some recommendations was modified in this update with a more refined application of the GRADE framework centred around patient important outcomes. This is highlighted in the rationale section of this update. A note is also made where the newly identified evidence did not alter the strength or certainty of evidence for previous recommendations. The recommendations presented here continue to cover various aspects of diagnosing soft tissue and bone infections, including the classification scheme for diagnosing infection and its severity. Guidance on how to collect microbiological samples, and how to process them to identify causative pathogens, is also outlined. Finally, we present the approach to treating foot infections in persons with diabetes, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and bone infections; when and how to approach surgical treatment; and which adjunctive treatments may or may not affect the infectious outcomes of diabetes-related foot problems. We believe that following these recommendations will help healthcare professionals provide better care for persons with diabetes and foot infections, prevent the number of foot and limb amputations, and reduce the patient and healthcare burden of diabetes-related foot disease.

Classification of foot ulcers in people with diabetes: A systematic review

BACKGROUND

Classification and scoring systems can help both clinical management and audit the outcomes of routine care.

AIM

This study aimed to assess published systems used to characterise ulcers in people with diabetes to determine which should be recommended to (a) aid communication between health professionals, (b) predict clinical outcome of individual ulcers, (c) characterise people with infection and/or peripheral arterial disease, and (d) audit to compare outcomes in different populations. This systematic review is part of the process of developing the 2023 guidelines to classify foot ulcers from the International Working Group on Diabetic Foot.

METHODS

We searched PubMed, Scopus and Web of Science for articles published up to December 2021 which evaluated the association, accuracy or reliability of systems used to classify ulcers in people with diabetes. Published classifications had to have been validated in populations of >80% of people with diabetes and a foot ulcer.

RESULTS

We found 28 systems addressed in 149 studies. Overall, the certainty of the evidence for each classification was low or very low, with 19 (68%) of the classifications being assessed by ≤ 3 studies. The most frequently validated system was the one from Meggitt-Wagner, but the articles validating this system focused mainly on the association between the different grades and amputation. Clinical outcomes were not standardized but included ulcer-free survival, ulcer healing, hospitalisation, limb amputation, mortality, and cost.

CONCLUSION

Despite the limitations, this systematic review provided sufficient evidence to support recommendations on the use of six particular systems in specific clinical scenarios.

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.

Risk factor analysis for diabetic foot ulcer-related amputation including Controlling Nutritional Status score and neutrophil-to-lymphocyte ratio

Diabetic foot ulcer often leads to amputation, and both nutritional status and immune function have been associated with this process. We aimed to investigate the risk factors of diabetic ulcer-related amputation including the Controlling Nutritional Status score and neutrophil-to-lymphocyte ratio biomarker. We evaluated data from hospital in patients with diabetic foot ulcer, performing univariate and multivariate analyses to screen for high-risk factors and Kaplan-Meier analysis to correlate high-risk factors with amputation-free survival. Overall, 389 patients underwent 247 amputations over the follow-up period. After correction to relevant variables, we identified five independent risk factors for diabetic ulcer-related amputation: ulcer severity, ulcer site, peripheral arterial disease, neutrophil-to-lymphocyte ratio and nutritional status. Amputation-free survival was lower for the moderate-to-severe versus mild cases, for the plantar forefoot versus hindfoot location, for the concomitant peripheral artery disease versus without and in the high versus low neutrophil-to-lymphocyte ratio (all p < 0.01). The results showed that ulcer severity (p < 0.01), ulcer site (p < 0.01), peripheral artery disease (p < 0.01), neutrophil-to-lymphocyte ratio (p < 0.01) and Controlling Nutritional Status score (p < 0.05) were independent risk factors for amputation in diabetic foot ulcer patients and have predictive values for diabetic foot ulcer progression to amputation.

IWGDF/IDSA Guidelines on the Diagnosis and Treatment of Diabetes-related Foot Infections (IWGDF/IDSA 2023)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the management and prevention of diabetes-related foot diseases since 1999. The present guideline is an update of the 2019 IWGDF guideline on the diagnosis and management of foot infections in persons with diabetes mellitus. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework was used for the development of this guideline. This was structured around identifying clinically relevant questions in the P(A)ICO format, determining patient-important outcomes, systematically reviewing the evidence, assessing the certainty of the evidence, and finally moving from evidence to the recommendation. This guideline was developed for healthcare professionals involved in diabetes-related foot care to inform clinical care around patient-important outcomes. Two systematic reviews from 2019 were updated to inform this guideline, and a total of 149 studies (62 new) meeting inclusion criteria were identified from the updated search and incorporated in this guideline. Updated recommendations are derived from these systematic reviews, and best practice statements made where evidence was not available. Evidence was weighed in light of benefits and harms to arrive at a recommendation. The certainty of the evidence for some recommendations was modified in this update with a more refined application of the GRADE framework centred around patient important outcomes. This is highlighted in the rationale section of this update. A note is also made where the newly identified evidence did not alter the strength or certainty of evidence for previous recommendations. The recommendations presented here continue to cover various aspects of diagnosing soft tissue and bone infections, including the classification scheme for diagnosing infection and its severity. Guidance on how to collect microbiological samples, and how to process them to identify causative pathogens, is also outlined. Finally, we present the approach to treating foot infections in persons with diabetes, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and bone infections; when and how to approach surgical treatment; and which adjunctive treatments may or may not affect the infectious outcomes of diabetes-related foot problems. We believe that following these recommendations will help healthcare professionals provide better care for persons with diabetes and foot infections, prevent the number of foot and limb amputations, and reduce the patient and healthcare burden of diabetes-related foot disease.

Preoperative and Perioperative Management of Diabetics Undergoing Elective Foot and Ankle Surgery

Diabetics are a highly comorbid population with an elevated risk profile when undergoing surgery. Proper preparation and management of modifiable risk factors can optimize outcomes in diabetics. A multidisciplinary approach to preoperative optimization, including surgeons, primary care providers, and anesthesiologists, ensures diabetic patients receive comprehensive evaluation before elective surgery. Orthopedic surgeons must understand preoperative optimization goals as they pertain to nutrition, glycemic control, and cardiovascular disease in diabetic patients.

The High Re-Ulceration Rate in Lower Extremity Amputation Intervention in Type 2 Diabetic Vietnamese Patients After 24-Month Follow-Up at Cho Ray Hospital, Vietnam

Diabetic foot ulcers (DFU) are a prevalent and severe disease with vascular and/or neurological complications, and if not diagnosed and treated promptly, it may rapidly deteriorate. Despite amputation or nonamputation treatment, there is still a high rate of re-ulceration. Previous studies have shown that the recurrence rate varies from 43% to 59% after 2 years. Currently, there is still a high rate of lower extremity amputation intervention, particularly above-the-ankle amputation, at Cho Ray Hospital in Vietnam, reaching 50%. The effectiveness of this intervention in the long term based on re-ulceration has not been evaluated in Vietnamese diabetic patients (DPs). This study aims to describe the long-term outcomes of amputation intervention in Type 2 DPs after 24 months and identify factors related to DFU recurrence in order to improve DFU management in low-middle-income countries like Vietnam. From January to June 2022, archived clinical and direct visit or phone follow-up data were collected and analyzed from diabetic foot ulcer patients with low extremity amputation who were treated at Cho Ray hospital from 2018 to 2020. The high re-ulceration rate in the 24th month was 29.8% (17/57), and the factor related to this outcome was "late diagnosis and care" (32.4 days vs 26.9 days with P = .03). Other potential factors (higher rates but no significant statistical difference with P > .05) included failure of HbA1c control greater than 9% (82.5% vs 67.5%), the severity of foot ulcers with TEXAS 3B (82% vs 60%), the number of years having diabetes (8.7 years vs 6.7 years), loss of monofilament sensation (82.5% vs 70.6%), and a history of diabetic foot ulcer (17.6% vs 10%). The re-ulceration after 24 months might depend on various clinical factors. Therefore, early diagnosis and care for diabetic foot ulcers could help reduce amputation rates and the risk of re-ulceration.

Role of bone biopsy and deep tissue culture for antibiotic stewardship in diabetic foot osteomyelitis

OBJECTIVES

To describe organisms most frequently identified on bone biopsy or deep tissue culture and determine how culture data impacted antibiotic management in patients with diabetic foot osteomyelitis (DFO).

METHODS

We retrospectively reviewed patients admitted with a diabetic foot ulcer (DFU) between 3 March 2018 and 31 December 2019 and selected for patients diagnosed with infectious osteomyelitis (OM) of the lower extremity. We stratified patients by whether a bone biopsy or deep tissue culture was obtained and compared rates of antibiotic utilization with chi-squared and Fisher's exact tests.

RESULTS

Of 305 patients with a DFU, 152 (50%) were clinically diagnosed with DFO. Forty-seven patients received 41 deep tissue cultures and 29 bone biopsy cultures for a total of 70 cultures. Of 45 (64%) positive cultures, 36 (80%) had Gram-positive organisms and 19 (42%) had Gram-negative organisms. MDR organisms were isolated in 7 (15%) patients. Culture data resulted in antibiotic changes in 41 (87%) patients. Therapy was narrowed in 29 (62%) patients and broadened due to inadequate empirical coverage in 4 (9%) patients. Culture data from 18 (40%) patients showed susceptibility to an oral treatment regimen with high bioavailability. There was no significant difference in rates of antibiotic utilization at discharge between patients who underwent bone biopsy or deep tissue culture relative to those who did not (77% versus 75%, P = 0.86), although less MRSA coverage was used (34% versus 50%, P = 0.047).

CONCLUSIONS

In patients with DFO, deep tissue and bone biopsy cultures were infrequently obtained but resulted in targeted therapy changes in most patients. Culture data usually allowed for narrowing of antibiotics but revealed inadequate empirical coverage in a subset of patients.

Limb Salvage in Severe Diabetic Foot Infection

Severe diabetic foot infections (DFI) are both limb threatening and life threatening and associated with negative impact on health-related quality of life. Most severe DFIs require surgical intervention, and the goal of treatment should be preservation of limb function in addition to eradication of infection. Minor amputations are required in approximately 40% and major amputations in approximately 20% of patients. Significant risk factors for lower extremity amputation included male gender, smoking, previous amputation, osteomyelitis, peripheral artery disease, retinopathy, severe infections, gangrene, neuroischemic diabetic foot infections, leukocytosis, positive wound cultures, and isolation of gram-negative bacteria.

The value of administering intravenous antibiotics during haemodialysis in the treatment of diabetic foot infections

OBJECTIVE

People with diabetes who are on haemodialysis (HD) are at a high risk of diabetic foot infections (DFI) and related complications. We explored the value of treating DFI with intravenous (IV) antibiotics during HD.

METHOD

This was an observational study of consecutively treated patients with DFIs with IV antibiotics during HD. Data collected included baseline characteristics, IV antibiotics used, details of multidisciplinary interventions and DFI treatment outcome.

RESULTS

A cohort of 11 patients, mean (±standard deviation) age 62.4±12.7 years, had 15 episodes of treatment with IV antibiotics during HD. Of the patients, six (54.5%) were male and nine (81.8%) had type 2 diabetes. The estimated mean glomerular filtration rate (eGFR) was 11.4±3.9ml/minute. All patients had infected foot ulceration, soft tissue infection, six (54.5%) patients had osteomyelitis, and two (18.2%) had wet gangrene. The commonest IV antibiotic used was vancomycin (10/15 episodes, 66.7%). Other IV antibiotics used were daptomycin and meropenem. In three episodes, oral ciprofloxacin was used with IV antibiotics. The mean duration of antibiotic treatment was 9.2±4.9 weeks. Of the episodes, 11 (73.3%) were treated successfully with IV antibiotics alone and two (13.3%) episodes required minor surgical debridement/amputation. Some 10 (90.9%) members of the cohort had peripheral arterial disease and of those, five (50%) underwent angioplasty during IV antibiotic treatment.

CONCLUSION

HD provides a good opportunity for treatment with IV antibiotics in DFI. This mode of administration of IV antibiotics, along with multidisciplinary intervention, is associated with ulcer healing and resolution of infection in over three-quarters of patients with DFI.

DECLARATION OF INTEREST

The authors have no conflicts of interest to declare.

Foot Osteomyelitis Location and Rates of Primary or Secondary Major Amputations in Patients With Diabetes

BACKGROUND

Diabetic foot osteomyelitis (DFO) often leads to amputations in the lower extremity. Data on the influence of the initial anatomical DFO localization on ultimate major amputation are limited.

METHODS

In this retrospective analysis, 583 amputation episodes in 344 patients (78 females, 266 males) were analyzed. All received a form of amputation in combination with antibiotic therapy. A multivariate logistic regression analysis with the primary outcome "major amputation" defined as an amputation above the ankle joint was performed. The association of risk factors including location of DFO, coronary artery disease, peripheral artery disease, neuropathy, nephropathy, and Charcot neuro-osteoarthropathy was analyzed.

RESULTS

Among 583 episodes, DFO was located in the forefoot in 512 (87.8%), in the midfoot in 43 (7.4%), and in the hindfoot in 28 episodes (4.8%). Overall, 53 of 63 (84.1%) major amputations were performed because of DFO in the setting of peripheral artery disease as primary indication. Overall, limb loss occurred in 6.1% (31/512) of forefoot, 20.9% (9/43) of midfoot, and 46.4% (13/28) of hindfoot DFO. Among these, 22 (41.5%) were performed as the primary treatment, whereas 31 (58.5%) followed previously failed minor amputations. Among this latter group of secondary major amputations, the DFO was localized to the forefoot in 23 of 583 (3.9%), the midfoot in 4 of 583 (0.7%) and the hindfoot in 4 of 583 (0.7%). In multivariate logistic regression analysis, initial hindfoot localization was a significant factor (P < .05), whereas peripheral artery disease, smoking, and a midfoot DFO were not found to be risk factors.

CONCLUSION

In our retrospective series, the frequency of limb loss in DFO increased with more proximal initial foot DFO lesions, with almost half of patients losing their limbs with a hindfoot DFO.

LEVEL OF EVIDENCE

Level IV, retrospective cohort study.

The Impact of Hospitalization for Diabetic Foot Infection on Health-Related Quality of Life: Utilizing PROMIS

Diabetic foot infections (DFI) are an increasingly common cause of hospitalizations. Once hospitalized with DFI, many patients require some level of amputation, often undergoing multiple operations. With increasing importance on patient-centered metrics, self-reported health-related quality of life (HRQOL) tools have been developed. This prospective cohort study aimed assessed the impact of DFI on HRQOL. Two hundred twenty-four patients completed the 29-item Patient-Reported Outcome Measurement Information System (PROMIS) and 12-Item Short Form (SF-12) survey. Secondary outcomes using the Foot and Ankle Ability Measures survey were obtained and included in the analysis. The study group was comprised of hospitalized patients with DFIs (n = 120), and the control group was comprised of patients with diabetes who were evaluated for routine outpatient foot care (n = 104); diabetic foot screening, wound care, onychomycosis, and/or callosities. Using this cohort, a propensity score-matched sample of hospitalized patients with DFI (n = 35) and control group patients (n = 35) was created for comparative analysis. The 2-independent sample t test was used to test for group differences on each of the PROMIS subscale outcomes. Using PROMIS, we found that hospitalized patients with DFI reported significantly worse HRQOL in 6 of 7 subscales (physical function, anxiety, depression, fatigue, social role, pain intensity; p value range: .0001-.02) compared to outpatients with diabetes evaluated for routine foot care. There was no significant difference between the 2 groups on sleep disturbance (p = .22). Patients hospitalized for DFI report lower HRQOL compared to patients with diabetes receiving routine outpatient foot care.

The association between estimated glomerular filtration rate and prognosis in patients with diabetic foot osteomyelitis

We aimed to explore the association between estimated glomerular filtration rate (eGFR) and prognosis in patients with diabetic foot osteomyelitis (DFO). Three hundred twenty‐one DFO inpatients were enrolled and classified into four groups according to the eGFRs as follows: normal (≥90), mildly reduced (60‐89), moderately reduced (30‐59) and severely reduced (<30). These patients were followed‐up for 6 months to observe the outcomes, including ulcer healing and amputation. The associations between eGFR and the outcomes were analysed by univariate and multivariate logistic regression models. Compared with patients with normal eGFR, patients with severely reduced eGFR group had higher risk of healing failure (OR = 4.72, 95% CI: 1.44‐15.48), total amputation (OR = 4.50, 95% CI: 1.18‐17.13) and minor amputation (OR = 4.05, 95% CI: (1.04‐15.87). Severely reduced eGFR in patients with DFO was an independent predictor for amputation and healing failure.

A Comparison of Adverse Short-Term Outcomes Following Forefoot Amputation Performed on an Inpatient Versus Outpatient Basis

The objective of this investigation was to evaluate short-term adverse outcomes following forefoot amputation with a specific comparison between those procedures performed on an inpatient versus outpatient basis. The 2018 American College of Surgeons National Surgical Quality Improvement Program database was interrogated to select those subjects with a 28805 current procedural terminology code (amputation, foot; transmetatarsal) that underwent the procedure with "all layers of incision (deep and superficial) fully closed." This resulted in 326 subjects who underwent the procedure on an inpatient basis and 72 subjects who underwent the procedure on an outpatient basis. Results of the primary outcome measures found no significant differences between groups with respect to the development of a superficial surgical site infection (5.8% vs 5.6%; p = .950), deep incisional infection (3.4% vs 5.6%; p = .380), or wound disruption (3.4% vs 6.9%; p = .163). Additionally, no significant differences were observed between groups with respect to unplanned reoperations (15.6% vs 12.5%; p = .500) or unplanned hospital readmissions (21.8% vs 23.6%; p = .957). The results of this investigation demonstrate no difference in short-term adverse outcomes following the performance of forefoot amputation with primary closure when the procedure is performed on an inpatient or outpatient basis. We hope that this information is utilized in future investigations specifically examining this clinical scenario as it relates to hospital admission criteria related to lower extremity tissue loss, length of hospital stay considerations, the timing of partial foot amputation following revascularization, and the economics of limb preservation.

The infection characteristics and autophagy defect of dermal macrophages in STZ-induced diabetic rats skin wound Staphylococcus aureus infection model

INTRODUCTION

Diabetic foot ulcer infection (DFI) is an infectious disease of the skin and soft tissue in diabetics notorious for making rapid progress and being hard to cure. Staphylococcus aureus (S. aureus), most frequently detected in DFI, recently was suggested as an intracellular pathogen that can invade and survive within mammalian host cells. Autophagy in macrophages plays a vital immune role in combating intracellular pathogens through bacterial destruction, but there is a lack of empirical research about the infection characteristics and autophagy in diabetic skin infection.

METHODS

Here, we used streptozotocin-induced Sprague Dawley rats as a diabetic skin wound model to examine the S. aureus clearance ability and wound healing in vitro. Western blot and immunofluorescence staining were used to evaluate the autophagic flux of the macrophages in diabetic rats dermis, even with S. aureus infection.

RESULTS

We demonstrated that infections in diabetic rats appeared more severe and more invasive with weakened pathogen clearance ability of the host immune system, which coincided with the suppressed autophagic flux in dermal macrophages, featured by a significant increase in endogenous LC3II/I and in p62.

CONCLUSIONS

Our results first provided convincing evidence that autophagy of macrophages was dysfunctional in diabetes, especially after being infected by S. aureus, which weakens the intracellular killing of S. aureus, potentially worsens the infections, and accelerates the infection spread in the diabetic rat model. Further understanding of the special immune crosstalk between diabetes host and S. aureus infection through autophagic factors will help to explain the complex clinical phenomenon and guarantee the development of effective therapies for diabetic foot infections.

Urine Albumin-Creatinine ratio is associated with prognosis in patients with diabetic foot osteomyelitis

AIMS

We aimed to explore the association between albuminuria and clinical outcomes in patients with diabetic foot osteomyelitis (DFO).

METHODS

This is an observational retrospective study and a total of 202 inpatients with DFO were eligible for inclusion in our study. Based on urine albumin-creatinine ratio (UACR), the patients were divided into three groups: normoalbuminuria group, microalbuminuria group and macroalbuminuria group. The data collected include demographics data, laboratory data, clinical diagnostic data, diabetic foot examination and clinical visit data. The association was then evaluated between albuminuria and all-cause mortality, major cardiovascular adverse events (MACE) and mixed endpoint events.

RESULTS

The mean age was 60.3 years, 62.9% were male and 45.05% were urinary protein-positive. The incidence rates of all-cause mortality, MACE and mixed endpoint events related to elevated UACR were significantly increased in patients with DFO (all P for trend < 0.01). After adjusting for confounders, compared with normoalbuminuria group, the risk of all-cause mortality, MACE and mixed endpoint events in the microalbuminuria group increased by 81.8%, 135.4% and 136.4%, respectively. The risk of all-cause mortality, MACE and mixed endpoint events in the macroalbuminuria group increased by 246.2%, 145.1% and 252.3%, respectively. The population attributable risk percentage (PAR%) suggested that 50.16% of all-cause mortality, 47.85% of MACE and 59.11% of mixed endpoint events could be attributed to the elevated UACR. Meanwhile, compared with normoalbuminuria, those with microalbuminuria or macroalbuminuria have lower apoA1 and ABI, higher SCr and higher incidence rate of CHD, hindfoot infection and severe infection (all P < 0.05).

CONCLUSIONS

In patients with DFO, the UACR level is associated with all-cause mortality, MACE and mixed endpoint events and elevated UACR levels increase the risk of all-cause mortality, MACE and mixed endpoint events.

The Influence of Multidrug-Resistant Bacteria on Clinical Outcomes of Diabetic Foot Ulcers: A Systematic Review

Multidrug-resistant organism infections have become important in recent years due to the increased prevalence of diabetic foot ulcers and their possible consequences. This study aimed to systematically review and evaluate ulcer duration, healing time, hospital stay, amputation, and mortality rates in patients with diabetic foot ulcers caused by infection with multidrug-resistant organisms. PubMed, the Cochrane Library, and Web of Science were searched in May 2020 to find observational studies in English about the clinical outcomes of multidrug-resistant organism infection in diabetic foot ulcers. Eight studies met the inclusion criteria, and these studies included 923 patients. The overall methodological quality of the study was moderate. Ulcer duration was described in six studies, and there was no practical association with multidrug-resistant organisms. Two out of three studies reported a longer healing time in multidrug-resistant organism infections than in non-multidrug-resistant organism infections. Clinical outcomes included the duration of hospitalisation, surgeries, amputations, and deaths. Lower limb amputation was the most reported clinical outcome in the included studies, and was more prevalent in the multidrug-resistant organism infections. We concluded that there was not enough evidence that multidrug-resistant organisms hindered the healing of diabetic foot ulcers. In contrast to the clinical outcomes, multidrug-resistant organisms affect both amputation rates and mortality rates.

Surgical Treatment and Management for Chronic Dislocated Subtalar Joint

Lateral dislocation of the subtalar joint is a relatively uncommon pathology. It has previously been described in the literature secondary to acute trauma. This form of dislocation can also be acquired and seen in severe long-standing cases of flatfoot and Charcot neuroarthropathy. This study aims to describe this "sidecar" deformity, etiologies of the deformity, and the surgical options for correction. This study was performed by reviewing medical records of a single foot and ankle surgeon for patients who met inclusion criteria and underwent surgical correction. The study period was from October 2010 to July 2017. Statistical analysis was performed using chart-review information to examine variables affecting selected outcome measures. The outcome measures evaluated were minor and major complications, as well as functional limb status. A total of 16 patients were included in the study. Etiology included 10 severe flatfoot deformities and 6 Charcot deformities. Seven patients underwent staged reconstruction, and 9 underwent a single-stage reconstruction. Seven patients (44%) had complications; all were major and required unplanned reoperation. In all 16 patients (100%), limb salvage and a functional limb resulted. We conclude that patients with a limb-threatening sidecar deformity can be successfully treated with reconstruction. This is challenging and associated with a high complication rate. Patients with a history of infection should be counseled on the possibility of requiring a staged reconstruction with multiple surgeries as well as the possibility of amputation.

[Multidisciplinary management of diabetic foot ulcer infection]

Infection is one of the most common complications of diabetic foot ulceration resulting in lower extremity amputations and early mortality in this population. Several factors influence the course of diabetic foot ulceration infection and in that context, integrated multidisciplinary management is required as soon as possible. In fact, a holistic interdisciplinary approach should be the standard of care. Whether the infection is categorized as mild, moderate or severe, with or without bone infection, the overall individual's characteristics must be addressed, in addition to local wound care, offloading and antibiotic therapy. Some severe infections have potential indications for hospitalization and are considered as surgical emergencies. In some DFU cases, surgical revascularization of the limb is mandatory to treat the infection. However, surgical interventions and amputations, are sometimes inevitable, they are predictors of bad prognosis. Although some adjuvant therapies are effective to promote wound healing, their use is not recommended to treat diabetic foot ulcer infection. Infection management can be divided into three general interventions: proper clinical diagnosis, microbiological and imaging investigations, and treatment. This review is an update on the up-to-date evidences in scientific literature and includes the latest recommendations from the International Working Group on the Diabetic Foot (IWGDF).

Risk Factors Associated with 30-Day Readmission in Patients with Diabetic Foot Infections

BACKGROUND

Diabetic foot infections (DFIs) are the most common cause of hospitalization for patients with diabetes. Studies have shown diabetic patients have high readmission rates. It is important to identify variables that contribute to readmission. This study aimed to investigate clinical variables associated with 30-day hospital readmission in patients with DFI.

METHODS

We conducted a retrospective study of adults admitted to the hospital for DFI between July 1, 2012, and July 1, 2015. We identified patients by International Classification of Diseases, Ninth Revision codes and randomly selected 35% of medical records for review. Patients were excluded if they did not have a DFI by review, were pregnant, or were incarcerated. The primary outcome was 30-day readmission. Data collected included baseline demographics, medical comorbidities, substance abuse, homelessness, tobacco use, and laboratory and surgical pathology data. Univariate and multivariate logistic regression models were used to identify independent predictors.

RESULTS

Of 140 included patients, 106 (76%) were male. Median age was 55 years and length of stay (LOS) was 7 days. In univariate analysis, 31 patients (22%) were readmitted in the 30 days after the index hospitalization. Factors associated with readmission included treatment failure, elevated C-reactive protein level, and hospital LOS (P < .05). In multivariate analyses, LOS and treatment failure were independent predictors of readmission.

CONCLUSIONS

The 30-day readmission rate for patients with DFI is high. Treatment failure, C-reactive protein, and LOS are independently associated with readmission. More work is needed to determine reasons for readmission so that appropriate measures can be taken before discharge.

Diabetic Foot. Part 1: Ulcers and Infections

Diabetes is a systemic disease that has achieved epidemic proportions in modern society. Ulcers and infections are common complications in the feet of patients with advanced stages of the disease, and are the main cause of amputation of the lower limb. Peripheral neuropathy is the primary cause of loss of the protective sensation of the feet and frequently leads to plantar pressure ulcers and osteoarticular disruption, which in turn develops into Charcot neuropathy (CN). Common co-factors that add to the morbidity of the disease and the risk of amputation in this population are obesity, peripheral arterial disease, immune and metabolic disorders. Orthopedic surgeons must be aware that the early detection and prevention of these comorbidities, through diligent medical care and patient education, can avoid these amputations.

Advanced glycation end products reduce macrophage-mediated killing of Staphylococcus aureus by ARL8 upregulation and inhibition of autolysosome formation

Staphylococcus aureus, a pathogen most frequently found in diabetic foot ulcer infection, was recently suggested as an intracellular pathogen. Autophagy in professional phagocytes like macrophages allows selective destruction of intracellular pathogens, and its dysfunction can increase the survival of internalized pathogens, causing infections to worsen and spread. Previous works have shown that S. aureus infections in diabetes appeared more severe and invasive, and coincided with the suppressed autophagy in dermal tissues of diabetic rat, but the exact mechanisms are unclear. Here, we demonstrated that accumulation of advanced glycation end products (AGEs) contributed to the diminished autophagy-mediated clearance of S. aureus in the macrophages differentiated from PMA-treated human monocytic cell line THP-1. Importantly, infected macrophages showed increased S. aureus containing autophagosome, but the subsequent fusion of S. aureus containing autophagosome and lysosome was suppressed in AGEs-pretreated cells, suggesting AGEs blocked the autophagic flux and enabled S. aureus survival and escape. At the molecular level, elevated lysosomal ARL8 expression in AGEs-treated macrophages was required for AGEs-mediated inhibition of autophagosome-lysosome fusion. Silencing ARL8 in AGEs-treated macrophages restored autophagic flux and increased S. aureus clearance. Our results therefore demonstrate a new mechanism, in which AGEs accelerate S. aureus immune evasion in macrophages by ARL8-dependent suppression of autophagosome-lysosome fusion and bactericidal capability.

Talectomy as Part of Chronic Foot and Ankle Deformity Correction Procedure: A Retrospective Study

Severe foot and ankle deformities can be associated with high complication rates and impaired quality of life in patients. Surgical correction using a talectomy procedure has previously been described in many lower extremity pathologies and is a powerful tool for the correction of severe foot and ankle deformity. This study aimed to describe the role of talectomy and the outcomes of this procedure in patients presenting with severe foot and ankle deformity. A review of 45 patients undergoing talectomy by a single surgeon was completed. Data extracted included the cause of deformity, history of infection, body mass index, and relevant comorbidities. Outcome measures of interest were minor or major complications and limb functionality at final follow-up. Statistical analysis was performed by using a Wilcoxon rank sum test and a Fisher exact test looking at variables affecting selected outcome measures. Limb salvage occurred in 38 of 45 patients (84.4%). Patients with an infection history had 89% lower odds of a functional limb at final follow-up (p = .0389). Six of 7 patients (85.7%) who ultimately underwent amputation had a history of prior infection. Women had 8.25 times higher odds of having a functional limb compared with men (p = .047). All 13 patients with major complications had neuropathy (p = .024). Patients with chronic lower extremity deformities can successfully be treated with a talectomy as a part of the reconstructive procedure. This is a challenging patient population that is associated with a high complication rate. Patients with a history of infection should be counseled on the possibility of requiring major amputation.

Infrared thermography for monitoring severity and treatment of diabetic foot infections

Monitoring of diabetic foot infections is largely based on clinical assessment, which is limited by moderate reliability. We conducted a prospective study to explore monitoring of thermal asymmetry (difference between mean plantar temperature of the affected and unaffected foot) for the assessment of severity of diabetic foot infections. In patients with moderate or severe diabetic foot infections (International Working Group on the Diabetic Foot infection-grades 3 or 4) we measured thermal asymmetry with an advanced infrared thermography setup during the first 4-5 days of in-hospital treatment, in addition to clinical assessments and tests of serum inflammatory markers (white blood cell counts and C-reactive protein levels). We assessed the change in thermal asymmetry from baseline to final assessment, and investigated its association with infection-grades and serum inflammatory markers. In seven included patients, thermal asymmetry decreased from median 1.8°C (range: -0.6 to 8.4) at baseline to 1.5°C (range: -0.1 to 5.1) at final assessment (P = 0.515). In three patients who improved to infection-grade 2, thermal asymmetry at baseline (median 1.6°C (range: -0.6 to 1.6)) and final assessment (1.5°C (range: 0.4 to 5.1)) remained similar (P = 0.302). In four patients who did not improve to infection-grade 2, thermal asymmetry decreased from median 4.3°C (range: 1.8 to 8.4) to 1.9°C (range: -0.1 to 4.4; P = 0.221). No correlations were found between thermal asymmetry and infection-grades (r = -0.347; P = 0.445), CRP-levels (r = 0.321; P = 0.482) or WBC (r = -0.250; P = 0.589) during the first 4-5 days of hospitalization. Based on these explorative findings we suggest that infrared thermography is of no value for monitoring diabetic foot infections during in-hospital treatment.

Advanced Glycation End Products Enhance Biofilm Formation by Promoting Extracellular DNA Release Through sigB Upregulation in Staphylococcus aureus

Bacterial biofilms do serious harm to the diabetic foot ulcer (DFU) because they play a crucial role in infection invasion and spread. Staphylococcus aureus, the predominant Gram-positive bacteria in diabetic foot infection (DFI), is often associated with colonization and biofilm formation. Through biofilm formation tests in vitro, we observed that S. aureus bacteria isolated from DFU wounds were more prone to form biofilms than those from non-diabetic patients, while there was no difference in blood sugar between the biofilm (+) diabetics (DB+) and biofilm (-) diabetics (DB-). Furthermore, we found that advanced glycation end products (AGEs) promoted the biofilm formation of S. aureus in clinical isolates and laboratory strains in vitro, including a methicillin-resistant strain. Analysis of biofilm components demonstrated that the biofilms formed mainly by increasing extracellular DNA (eDNA) release; remarkably, the S. aureus global regulator sigB was upregulated, and its downstream factor lrgA was downregulated after AGE treatments. Mechanism studies using a sigB-deleted mutant (Newman-ΔsigB) confirmed that AGEs decreased expression of lrgA via induction of sigB, which is responsible for eDNA release and is a required component for S. aureus biofilm development. In conclusion, the present study suggests that AGEs promote S. aureus biofilm formation via an eDNA-dependent pathway by regulating sigB. The data generated by this study will provide experimental proof and theoretical support to improve DFU infection healing.

Diagnosis of infection in the foot in diabetes: a systematic review

BACKGROUND

Securing an early accurate diagnosis of diabetic foot infections and assessment of their severity are of paramount importance since these infections can cause great morbidity and potentially mortality and present formidable challenges in surgical and antimicrobial treatment.

METHODS

In June 2018, we searched the literature using PuEbMed and EMBASE for published studies on the diagnosis of diabetic foot infection. On the basis of predetermined criteria, we reviewed prospective controlled, as well as noncontrolled, studies in any language, seeking translations for those not in English. We then developed evidence statements on the basis of the included papers.

RESULTS

From the 4242 records screened, we selected 35 papers that met our inclusion criteria. The quality of all but one of the evidence statements was low because of the weak methodology of nearly all of the studies. The available data suggest that diagnosing diabetic foot infections on the basis of clinical signs and symptoms and classified according to the International Working Group of the Diabetic Foot scheme correlates with the patient's likelihood of ulcer healing, of lower extremity amputation, and risk of death. Elevated levels of selected serum inflammatory markers are supportive, but not diagnostic, of soft tissue or bone infection. In patients with suspected diabetic foot osteomyelitis, both a positive probe-to-bone test and an elevated erythrocyte sedimentation rate are strongly associated with its presence. Culturing tissue samples of soft tissues or bone, when care is taken to avoid contamination, provides more accurate microbiological information than culturing superficial (swab) samples. Plain X-ray remains the first-line imaging examination when there is suspicion of diabetic foot osteomyelitis, but advanced imaging methods help in cases when either the diagnosis or the localization of infection is uncertain.

CONCLUSION

The results of this first reported systematic review on the diagnosis of diabetic foot infections provide some guidance for clinicians, but there is a need for more prospective controlled studies of high quality.

Guidelines on the diagnosis and treatment of foot infection in persons with diabetes (IWGDF 2019 update)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the prevention and management of diabetic foot disease since 1999. This guideline is on the diagnosis and treatment of foot infection in persons with diabetes and updates the 2015 IWGDF infection guideline. On the basis of patient, intervention, comparison, outcomes (PICOs) developed by the infection committee, in conjunction with internal and external reviewers and consultants, and on systematic reviews the committee conducted on the diagnosis of infection (new) and treatment of infection (updated from 2015), we offer 27 recommendations. These cover various aspects of diagnosing soft tissue and bone infection, including the classification scheme for diagnosing infection and its severity. Of note, we have updated this scheme for the first time since we developed it 15 years ago. We also review the microbiology of diabetic foot infections, including how to collect samples and to process them to identify causative pathogens. Finally, we discuss the approach to treating diabetic foot infections, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and for bone infections, when and how to approach surgical treatment, and which adjunctive treatments we think are or are not useful for the infectious aspects of diabetic foot problems. For this version of the guideline, we also updated four tables and one figure from the 2016 guideline. We think that following the principles of diagnosing and treating diabetic foot infections outlined in this guideline can help clinicians to provide better care for these patients.

Do SIRS Criteria Predict Clinical Outcomes in Diabetic Skin and Soft Tissue Infections?

The aim of this study was to assess whether systemic inflammatory response syndrome (SIRS) is correlated with outcomes in diabetic foot infections (DFIs). We retrospectively reviewed 137 diabetic patients admitted to the hospital with Infectious Diseases Society of America moderate and severe DFIs. We used SIRS criteria to define severe infection based on the presence of at least 2 of the following: heart rate >90 bpm, temperature >38°C or <36°C, respiratory rate >20 breaths per minute, and white blood cell count >12,000/mm³ or <4,000/mm³. Patients with severe DFI were significantly younger (median 49.6 versus 53.6 years, p = .04), less often had type 2 diabetes (88.6% versus 98.9%, p = .01), and less often had a history of previous amputation (15.9% versus 40.9%, p < .01). There were no differences in patients with severe infections defined by SIRS versus moderate infections in the need for surgery (47.7% versus 59.1%, p = .27), any amputation (20.5% versus 29.0%, p = .29), leg amputations (6.8% versus 7.5%, p = .88), duration of antibiotics (median ± standard deviation 34.1 ± 46.5 versus 31.9 ± 47.2 days, p = .47), or healing within 1 year (68.2% versus 66.7%, p = 1.00). Length of hospital stay was the only outcome variable that was significantly different in severe infections (median 12.7 ± 11.9 versus 7.8 ± 5.8 days, p = .02). Foot-related readmission was more common in moderate infections (46.2% versus 25.0%, p = .02). In conclusion, SIRS criteria for severe infections in diabetic patients with skin and soft tissue infections were not associated with a difference in outcomes other than longer hospital stay.

Meta-analysis of risk factors for amputation in diabetic foot infections

BACKGROUND

Knowledge of risk factors is crucial to develop management and treatment protocols for the prevention of lower extremity amputation for patients with diabetic foot infections (DFIs).

METHODS

We searched the research literature for studies reporting risk factors for lower extremity amputation in patients with DFI. The main outcome variables included both minor and major amputations. This study was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, and the protocol was registered in PROSPERO (CRD42018118543).

RESULTS

A total of 2471 potential articles from the database search met the inclusion criteria. After reviewing the titles, abstracts, and full texts, remaining 25 articles were included in the final analysis. We identified 6132 patients with DFI in the 25 included articles. Of these, 1873 patients who underwent amputation were investigated. Male gender (odds ratio [OR]: 1.31), smoking (OR: 1.38), history of amputation (OR: 1.47), history of osteomyelitis (OR: 1.94), peripheral arterial disease (OR: 2.35), retinopathy (OR: 1.32), International Working Group on the Diabetic Foot (IWGDF) grades 3 and 4 (OR: 1.7 and 2.5), Wagner grades 4 and 5 (OR: 4.3 and 6.4), gangrene/necrosis (OR: 9.9), osteomyelitis (OR: 4.5), neuroischaemic DFI (OR: 3.06), severe infection (OR: 3.12), length of hospitalization (standardized mean difference [SMD]: 0.7), leukocytosis (OR: 1.76), mean erythrocyte sedimentation rate (ESR) (SMD: 0.5), mean C-reactive protein (CRP) (SMD: 0.8), tissue culture positivity (OR: 1.61), and isolation of Gram-negative bacteria from tissue culture (OR: 1.5) were found as predictors of amputation in DFI.

CONCLUSIONS

The present study highlighted some differences in diabetic foot ulcers and DFIs in terms of risk factors for lower extremity amputation. These data provide detailed information about risk factors for amputations among patients with DFI, thus contributing to the creation of new classification systems for assessment of high-risk patients.

Plantar Approach for Midfoot Wedge Resection to Reconstruct the Rocker Bottom Foot

Chronic deformity of the foot can lead to ulceration, infection, and amputation. Midfoot wedge osteotomy for deformity correction has been described in the literature; however, most reports are case review or small series. Wedge osteotomy can be performed from a medial or plantar approach, but there are limited data on outcomes regarding these relatively uncommon procedures. This study aims to review a population of patients with a rocker bottom foot deformity that underwent a midfoot wedge resection performed from the plantar surface for deformity correction, wound healing, and limb salvage. A review of medical records from a single foot and ankle surgeon was undertaken. Patients who had a midfoot wedge performed from the plantar surface to address rocker bottom deformity resulting from Charcot neuroarthropathy or severe flatfoot were included. Thirty patients met inclusion criteria. The outcome measures evaluated were minor and major complications, wound healing, and functional limb status. Statistical analysis was performed to evaluate factors that influenced outcomes. At time of final follow up, 17 of 20 (85%) preoperative wounds had healed. Mean preoperative talo-first metatarsal angle was -25° and improved to -5° postoperatively. An 87% limb salvage rate (26/30) was demonstrated. Body mass index was the only statistically significant factor that influenced functional limb status. Maintaining a functional limb can have profound effects on a patient's quality of life. Generally, patients with this severe rocker bottom foot deformity have multiple comorbidities and are at an increased risk of major amputation and early death. The current study has shown that patients with a rocker bottom foot deformity can benefit from midfoot wedge resection from a plantar approach to achieve a plantigrade foot.

How to Create a Hot Foot Line to Prevent Diabetes-Related Amputations: Instant Triage for Emergency Department and Inpatient Consultations

Emergency department visits for lower extremity complications of diabetes are extremely common throughout the world. Surprisingly, recent data suggest that such visits generate an 81.2% hospital admission rate with an annual bill of at least $1.2 billion in the United States alone. The likelihood of amputation and other subsequent adverse outcomes is strongly associated with three factors: 1) wound severity (degree of tissue loss), 2) ischemia, and 3) foot infection. Using these factors, this article outlines the basic principles needed to create an evidence-based, rapid foot assessment for diabetic foot ulcers presenting to the emergency department, and suggests the establishment of a "hot foot line" for an organized, expeditious response from limb salvage team members. We present a nearly immediate assessment and referral system for patients with atraumatic tissue loss below the knee that has the potential to vastly expedite lower extremity triage in the emergency room setting through greater collaboration and organization.

Short-term predictors of amputation in patients with diabetic foot ulcers

BACKGROUND

Diabetic foot ulcers are the leading cause of non-traumatic lower extremity amputation. The aim of this study was to establish short-term predictors of lower extremity amputation (LEA) in patients with diabetic foot ulcers (DFU).

METHODS

A retrospective observational study was performed. Patients observed for the first time in a multidisciplinary outpatient diabetic foot clinic during 1-year were reviewed. We examined demographic and clinical data and the occurrence of LEA within 180 days. Bivariate descriptive analysis was performed and three logistic regression models were created to predict short-term LEA.

RESULTS

During 1-year 613 patients were observed for the first time in our diabetic foot clinic. Relevant data and eligibility was available from 479 patients with DFU; 38.41%, 40,71% and 20,88% had neuropathic, neuroischemic and ischemic ulcers, respectively. Considering a follow-up of 180 days, amputation occurred in 10.02% (n = 48) of patients: 3.13% (n = 15) major amputation and 6.89% (n = 33) minor amputation. Independent predictors of short-term LEA included moderate to severe infection [OR 5.23 (IC 95% 2.51-10.80; p < 0.001)], previous history of LEA [OR 3.93 (IC 95% 1.81-8.53; p = 0.001)], peripheral arterial disease [OR 3.51 (IC 95% 1.29-9.58; p = 0.014)] and presence of any walking disability [OR 3.35 (IC 95% 1.58-7.13; p = 0.002)].

CONCLUSION

In DFU patients the risk of LEA at 180 days is associated to moderate to severe infection at the initial presentation, previous history of LEA, peripheral arterial disease and presence of any walking disability. To prevent future amputations these patients should be identified early and managed by a multidisciplinary team.

LEVEL OF CLINICAL EVIDENCE

Level 2.

The Evaluation and Treatment of Diabetic Foot Ulcers and Diabetic Foot Infections

Diabetic foot ulcers and infections are common complications of diabetic foot disease. Additionally, these complications are a common cause of morbidity and impose a substantial burden to the patient and society. It is imperative to understand the major contributing factors, namely, diabetic neuropathy, peripheral arterial disease, and immune system dysfunction in order to guide treatment. Management of diabetic foot disease begins with a detailed history and thorough physical examination. This examination should focus on the manifestations of diabetic neuropathy and peripheral arterial disease, and, in particular, any evidence of diabetic foot ulcers or infection. Prevention strategies should include a multi-disciplinary approach centered on patient education.

Diabetic Foot Infections: Update on Management

PURPOSE OF REVIEW

Diabetic foot infections (DFIs) are common in patients with diabetes mellitus complicated by foot ulcers and can be classified in different categories based on their severity. In this report, we present the diagnosis and management of DFIs according to their classification.

RECENT FINDINGS

While appropriate antibiotic regiments and surgical techniques for the treatment of DFIs are well established, new technologies and techniques for example in medical imaging, wound care modalities, and supplementary therapy approaches show potentially promising results in preventing DFIs. As with every complex disease, fine tuning DFI management can be challenging as it requires careful evaluation of different parameters. It demands timely action, close collaboration of different specialties, and patient cooperation.

Foot and Ankle Surgery in the Diabetic Population

The surgical treatment of diabetic patients can be challenging. The physiologic and metabolic abnormalities seen in diabetic patients can adversely affect healing and outcomes in even the simplest of procedures. This article examines some of the special considerations in the treatment of diabetic patients undergoing foot and ankle surgeries.

The Role of Serum Procalcitonin, Interleukin-6, and Fibrinogen Levels in Differential Diagnosis of Diabetic Foot Ulcer Infection

AIMS

We aimed to evaluate the roles of interleukin-6 (IL-6), PCT, and fibrinogen levels in the differential diagnosis of the patients with infected diabetic foot ulcer (IDFU) and noninfected diabetic foot ulcer (NIDFU) and to compare those with C-reactive protein (CRP), white blood cell (WBC), and erythrocyte sedimentation rate (ESR).

METHODS

Patients over 18 years with a diagnosis of type 2 diabetes mellitus and DFU who were followed up in our hospital between 1 January 2016 and 1 January 2017 were included in the study. In addition to this patient group, patients with diabetes but without DFU were determined as the control group.

RESULTS

Thirty-eight patients with IDFU, 38 patients with NIDFU, and 43 patients as the control group were included in the study. Fifty-six point three percent of the patients who participated in the study were males, and the mean age was 61.07 ± 11.04 years. WBC, ESR, CRP, IL-6, and fibrinogen levels of the cases with IDFU were determined to be significantly higher compared to the cases in NIDFU (p < 0.01). The area under the ROC curve (AUROC) value was highest for CRP (0.998; p < 0.001), and the best cut-off value for CRP was 28 m/L. The best cut-off values for fibrinogen, IL-6, ESR, and WBC were 480 mg/dL, 105.8 pg/mL, 31 mm/h, and 11.6 (103 μ/L), respectively.

CONCLUSION

Serum PCT levels were not found to be effective in the discrimination of IDFU and NIDFU. Serum IL-6 and fibrinogen levels seem to be two promising inflammatory markers in the discrimination of IDFU.

Inpatient Management of Diabetic Foot Infections: A Review of the Guidelines for Hospitalists

Diabetic foot infections (DFIs) are common and represent the leading cause for hospitalization among diabetic complications. Without proper management, DFIs may lead to amputation, which is associated with a decreased quality of life and increased mortality. However, there is currently significant variation in the management of DFIs, and many providers fail to perform critical prevention and assessment measures. In this review, we will provide an overview of the diagnosis, management, and discharge planning of hospitalized patients with DFIs to guide hospitalists in the optimal inpatient care of patients with this condition.

Risk factors for amputation in patients with diabetic foot infection: a prospective study

There is a variety of diagnostic and therapeutic algorithms for diabetic foot infections (DFIs). Some of them are too difficult to be applied in routine clinical approach. In the routine clinical approach, it is necessary to find new risk factors and end up with a quick and easy assessment of DFIs. In this study, we aimed to evaluate the independent risk factors for osteomyelitis, amputation and major amputation in patients with DFI using standard scoring procedures. We prospectively studied 379 patients with DFI. The variables were analysed using logistic analysis. A total of 126 cases (33·2%) underwent amputation. The odds ratios in the amputation model were 3·09 for osteomyelitis (P < 0·001), 4·90 for arterial stenosis (AS) (P < 0·001), 3·67 for the history of DFI (P = 0·001), 2·47 for ulcer duration >60 days (P = 0·001), 3·10 for ulcer depth > 15 mm (P < 0·001) and 10·28 for fungal DFI (P = 0·015). In this study, the unusual result of well-known literature was fungal DFI as an independent risk factor for amputation in patients with DFI.

Factors Associated with a Prolonged Length of Hospital Stay in Patients with Diabetic Foot: A Single-Center Retrospective Study

BACKGROUND

We conducted this study to identify factors that may prolong the length of the hospital stay (LHS) in patients with diabetic foot (DF) in a single-institution setting.

METHODS

In this single-center retrospective study, we evaluated a total of 164 patients with DF, and conducted an intergroup comparison of their baseline demographic and clinical characteristics, including sex, age, duration of diabetes, smoking status, body mass index, underlying comorbidities (e.g., hypertension or diabetic nephropathy), wound characteristics,type of surgery, the total medical cost, white blood cell (WBC) count, C-reactive protein (CRP) levels, erythrocyte sedimentation rate, and albumin, protein, glycated hemoglobin, and 7-day mean blood glucose (BG) levels.

RESULTS

Pearson correlation analysis showed that an LHS of >5 weeks had a significant positive correlation with the severity of the wound (r=0.647), WBC count (r=0.571), CRP levels (r=0.390), DN (r=0.020), and 7-day mean BG levels (r=0.120) (P<0.05). In multiple regression analysis, an LHS of >5 weeks had a significant positive correlation with the severity of the wound (odds ratio [OR]=3.297; 95% confidence interval [CI], 1.324-10.483; P=0.020), WBC count (OR=1.423; 95% CI, 0.046-0.356; P=0.000), CRP levels (OR=1.079; 95% CI, 1.015-1.147; P=0.014), albumin levels (OR=0.263; 95% CI, 0.113-3.673; P=0.007), and 7-day mean BG levels (OR=1.018; 95% CI, 1.001-1.035; P=0.020).

CONCLUSIONS

Surgeons should consider the factors associated with a prolonged LHS in the early management of patients with DF. Moreover, this should also be accompanied by a multidisciplinary approach to reducing the LHS.

Effect of Negative Pressure Wound Therapy on Cellular Fibronectin and Transforming Growth Factor-β1 Expression in Diabetic Foot Wounds

BACKGROUND

Chronic diabetic foot wounds are a leading cause of amputation, morbidity, and hospitalization for patients with diabetes. Negative-pressure wound therapy (NPWT) can putatively facilitate wound healing, but the underlying mechanisms remain unclear. Cellular fibronectin (cFN) and transforming growth factor-β1 (TGF-β1) play an important role in wound healing. This prospective randomized controlled trial evaluated the effects of NPWT on the production of cFN and the expression of TGF-β1 in diabetic foot wounds of patients.

METHODS

From January 2012 to January 2015, 40 patients with diabetic foot wounds were randomly and equally apportioned to receive either NPWT or advanced moist wound therapy (control) for 7 days. Granulation tissue was harvested before and after treatment. Immunohistochemistry and Western blot were performed to evaluate protein levels of cFN and TGF-β1, and real-time polymerase chain reaction (PCR) to measure corresponding mRNA expressions.

RESULTS

NPWT facilitated the expression of cFN and TGF-β1 in diabetic foot wounds. Immunohistochemical analysis revealed higher levels of cFN and TGF-β1 in the NPWT group than in the control group. Western blot and real-time PCR analysis further showed that protein and mRNA levels of cFN or TGF-β1 were higher in the NPWT group than that in the control group ( P < .01, both).

CONCLUSION

Our results showed that NPWT facilitated the production of cFN and the expression of TGF-β1 in granulation tissue in diabetic foot ulcers.

LEVEL OF EVIDENCE

Level I, randomized controlled study.

Prescribing antibiotics in diabetic foot infection: what is the role of initial microscopy and culture of tissue samples?. Int Wound J 2017;14:685-690. [PMID: 27696697 PMCID: PMC7950145 DOI: 10.1111/iwj.12674]

The aim of this study was to evaluate the role of microscopy, Gram stain and the culture of tissue samples in the antibiotic treatment of patients with diabetic foot infection. A retrospective review of patients with a diabetic foot infection was undertaken. Data analysed included the severity of infection, antibiotic prescribing patterns, microscopy and culture results. A total of 71 patients were included, from whom 114 tissue samples were collected. Gram stain results were in agreement with final culture results in 45·8% (n = 54) of samples. Overall sensitivity and specificity of the Gram stains were low (74·5% and 69·8%, respectively), although the specificity for Gram-negative rods was high (98·5%). The presence or absence of 'pus cells' on microscopy was a poor predictor of culture results. Empirical prescribing of antibiotics was in accordance with local policy in 31·1% of patients, improving to 86·8 % following culture results. Microscopy, a skilled laboratory procedure, was generally a poor predictor of tissue culture results. However, the presence of Gram-negative rods was suggestive of isolation in the culture of such organisms and could allow the early broadening of antibiotic treatment. Despite initial poor compliance of empirical antibiotic treatment regimens, prescribing was adjusted in light of culture results, suggesting these were important for clinicians.

Comparison of Transtibial Amputations in Diabetic Patients With and Without End-Stage Renal Disease

BACKGROUND

The primary purpose of this retrospective study was to report on a consecutive series of 102 patients with diabetes mellitus (DM) who underwent transtibial amputation (TTA) for chronic infections and nonreconstructable lower extremity deformities. A secondary aim was to compare the outcomes of TTA patients with end-stage renal disease on dialysis (ESRD) to patients without ESRD, and to identify risk factors for mortality after TTA.

METHODS

This cohort involved a consecutive series of patients who were treated by a single surgeon. The TTA patients were divided into 2 groups for analysis. The study group included those patients with ESRD who underwent TTA, and the control group included those patients who did not have ESRD.

RESULTS

At the time of final follow-up, 64 of 102 patients were ambulatory with a prosthesis. There was a significant improvement in ambulatory status after amputation (preoperatively 45.1%, postoperatively 62.7%, P = .02). Wound healing complications (infection and/or dehiscence) occurred in 31 of 102 patients and led to a transfemoral amputation in 4 patients. After TTA patients with ESRD were significantly more likely to die (52.4% vs. 23.5%, p <0.05) and significantly less like to ambulate (42.9% vs. 67.9%, p <0.05) than patients without ESRD. Contralateral foot problems after the TTA occurred in 33 of 97 patients and resulted in 10 patients undergoing a contralateral transtibial amputation. Excluding patients with bilateral amputations (5 prior to and 10 after the index amputation), 64 of 87 patients with successful unilateral transtibial amputations were able to ambulate with a prosthesis. Thirty of 102 patients (29.4%) died during the follow-up period, and 6 of these deaths occurred during the perioperative period (within 30 days of surgery). There were no significant differences between the 2 groups with regard to the use of staged TTA, need for transfemoral amputation, or wound healing problems at the amputation site. Patients who were unable to walk postoperatively had a calculated 5-year survival rate of 30.1%, whereas those who were ambulatory had a 5-year survival rate of 68.8%. Cox proportional hazards model demonstrated a 62% reduced risk of mortality in patients who were able to ambulate after LEA compared with those patients who were not able to ambulate.

CONCLUSION

TTA in patients with diabetes was associated with substantial morbidity and mortality. Risk factors that were significantly associated with an increased rate of mortality were the presence of ESRD, age ≥56 years, and inability to ambulate postoperatively.

LEVEL OF EVIDENCE

Level III, retrospective case controlled study.