The Diabetic Foot

An novel and alternative treatment method for large heel ulceration in diabetic patients: Proximal tibial cortex transverse distraction

Heel ulceration in patients with diabetes mellitus (DM) is a major clinical challenge, manifesting with a protracted and uncertain healing process. The prefer treatment of heel ulceration is still controversial. This study aims at describing a newly alternative surgical method with the proximal transverse tibial bone transport technique, as an attempt to achieve wound healing in diabetic patients with large heel ulceration. Retrospective clinical study. A total of 21 diabetic patients with large heel ulceration were enrolled and followed up at least 6 months. The following parameters were assessed: Visual analogue scale (VAS), healing time, ulcer healing rate, ulcer recurrence rate and limb salvage rate. All patients got fully follow-up and achieved wound healing uneventfully. Eighteen patients returned to independent walking without any helper while three patients walked using a crutch. Limb salvage was achieved in all 21 patients (100%). The mean wound area was 67.43 ± 13.31 cm2 (range: 46-97 cm2 ). The mean healing time was 128.62 ± 16.76 days (range: 91-160 days). 16 out of 21 patients without calcaneal osteomyelitis achieved ulcer healing with a mean duration of 124.69 ± 14.42 days (range: 91-143 days), while the other five patients with calcaneal osteomyelitis were 141.20 ± 19.12 days (range: 110-160 days). 2 out of 21 patients got superficial rupture at the previous wounds and healed after outpatient dressing change combined with oral antibiotics. The novel technique described is particularly applicable for large heel ulceration in diabetic patients. It offers a better alternative for achieving wound healing with a favourable encouraging outcome.

A Clinical Significance of Fungal Infections in Diabetic Foot Ulcers

Background: Diabetic foot ulcers (DFUs) are the most common and serious complications in uncontrolled diabetes. Infections are predominantly polymicrobial, with aerobic Gram-positive, anerobic, and fungal infections. Early detection of fungal infection and initiation of appropriate treatment in DFUs may lead to better healing and avoid amputations. The primary objective was to find out the prevalence of DFUs getting infected with fungus and the secondary objective was to identify the appropriate methodology for the detection of the fungus in DFUs.

Materials and methods: This was a cross-sectional observational study carried out in a tertiary care hospital with a sample size of 60 DFUs. Microbiological analysis was done by swab culture and deep tissue culture. Observational data were collected and the significance level was statistically analyzed.

Results: In the present study, the prevalence of fungal infections in DFUs was 31.7%. Only fungal tissue was positive in 15%, the fungal swab was positive in 8.33%, and both tissue and swab were positive in 8.33%. All these patients were treated with antifungal treatment as per the culture report in addition to appropriate antimicrobial therapy.

Conclusion: A fungal culture should be done in all patients with non-healing DFUs. Both fungal swab and tissue culture testing should be advocated in patients with DFUs for better mycological evaluation. The addition of antifungal medications may provide better outcomes in selected cases.

Development and Usability Evaluation of a Telemedicine System for Management and Monitoring of Patients with Diabetic Foot

Objectives: The aim of the present study was to develop and evaluate the usability of a telemedicine system for management and monitoring of patients with diabetic foot.Methods: This study was conducted in four phases. In the first phase, the information needs and characteristics required to design the telemedicine system were identified based on a literature review. Then, in a two-stage Delphi survey, 15 experts approved the identified information needs and characteristics. The prototype telemedicine system was then designed. In the third phase, system usability was evaluated through a semi-structured interview. In the fourth phase, users’ satisfaction with the designed system was analyzed.Results: Out of 115 information needs and required characteristics, 95 were considered in the system design. Eight main pages for enabling patient-physician interactions and physician-physician interactions, monitoring the patient and controlling the disease process, providing medical consultation, and prescribing medications were considered. In the third phase, 26 distinct problems were identified. However, 75% of the participants were very satisfied with the system.Conclusions: This study presents an attempt to design and evaluate a telemedicine system for the management and monitoring of patients with diabetic foot. In this system, patients receiving medical services or physicians who encounter rare cases can send the complete medical history, clinical test results, and videos and images related to the foot to specialist physicians. After examining the medical history or images and videos, the physician can provide the necessary medication prescriptions and laboratory tests or other recommendations.

Monitoring of external predisposing factors for Diabetic Foot: A literature review and physicians' perspectives

Background: Diabetic foot is one of the most important complications of diabetes caused by the existence of some destructive factors in different anatomical locations of feet. Management and monitoring of these factors are very important to decrease or avoid ulcerating lesions of the foot. The purpose of this study is to identify and introduce the predisposing factors and anatomical locations associated with these destructive factors. Methods: First, we conducted a comprehensive review of different databases to identify the factors and associated anatomical locations from the previous studies. Then, we designed a questionnaire and invited physicians and specialists to express their perspectives on these factors and locations. The data were analyzed using SPSS version 23. Frequency, percentage, mean and standard deviation of these variables were calculated. Results: Based on the literature review, four factors, including pressure, moisture and sweat, temperature, and acceleration were identified as factors destructive to the tissues of the diabetic foot and worsen ulcers. The view of specialists approved the results of the literature review. Besides, there was an insignificant difference between the results of the literature review and the specialists' view in terms of anatomical locations that need to be continuously monitored. Conclusion: Monitoring the pressure in heel, first metatarsal, and first metatarsal head; moisture and sweat under the fingers, hallux and heels as well as the temperature at the first metatarsal, first metatarsal head, and the third metatarsal head are important in preventing ulceration, destructing the foot tissue, and accelerating the treatment process.

Systematic review of randomized controlled trials on antibiotic treatment for osteomyelitis in diabetes

AIM

To evaluate the efficacy of antibiotic therapy in osteomyelitis treatment among people with diabetes.

METHODS

A systematic search of PubMed, EMBASE, AMED, Web of Science, the WHO trial registry, Cochrane library databases, and ClinicalTrials.gov, in addition to hand-searching, was undertaken in July 2018. Two reviewers independently extracted data. The studies' methodological quality was assessed using the modified Jadad scale. Descriptive analysis was performed.

RESULTS

Seven randomized controlled trials, with 393 participants in total, were included. The antibiotic regimens, treatments and follow-up durations varied among the trials. The total scores showed that the overall methodological quality of the seven studies was high, despite two studies showing some flaws in double-blinding and withdrawals/drop-outs. Of four studies comparing different antibiotic regimens, three implied a similar remission effect, while one implied that ertapenem ± vancomycin treatment showed a higher remission rate than tigecycline treatment; this conclusion was not robust because of low power and small sample size. In the other three studies, which included two different doses of ciprofloxacin, an antibiotics group and a conservative surgical group, and two durations of the same antibiotic strategy, no significant differences in remission were reported between the groups. No difference was observed in the analyses of microbiological outcomes, superinfections and relapse, except adverse events.

CONCLUSIONS

There is no definitive evidence supporting the superiority of any particular antibiotic agent, dose, or administration duration in the treatment of osteomyelitis in diabetes. As the included studies had some flaws and limitations, further research is necessary.

On the Cutting Edge: Wound Care for the Endovascular Specialist

Clinical outcomes in patients with critical limb ischemia (CLI) depend not only on endovascular restoration of macrovascular blood flow but also on aggressive periprocedural wound care. Education about this area of CLI therapy is essential not only to maximize the benefits of endovascular therapy but also to facilitate participation in the multidisciplinary care crucial to attaining limb salvage. In this article, we review the advances in wound care products and therapies that have granted the wound care specialist the ability to heal previously nonhealing wounds. We provide a primer on the basic science behind wound healing and the pathogenesis of ischemic wounds, familiarize the reader with methods of tissue viability assessment, and provide an overview of wound debridement techniques, dressings, hyperbaric therapy, and tissue offloading devices. Lastly, we explore emerging technology on the horizons of wound care.

Lysozyme-Antimicrobial Peptide Fusion Protein Promotes the Diabetic Wound Size Reduction in Streptozotocin (STZ)-Induced Diabetic Rats

Background

Lysozymes and antibacterial peptides have been confirmed to protect humans against viral and bacterial infection, and accelerate wound healing. The study aimed to evaluate the effect of lysozyme-antimicrobial peptide fusion protein on the diabetic wound size reduction in streptozotocin (STZ)-induced diabetic rats.

Material/Methods

Diabetic rats were prepared via intraperitoneal injection of STZ, 70 mg/kg. A 2-cm circular incision with full thickness was made on the dorsum skin of the rats for preparation of diabetic wound model. The wounds were treated with the fusion protein or phosphate buffer saline.

Results

The fusion protein markedly accelerated wound healing, decreased levels of proinflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α, lipid peroxide (LPO) content, and expression of cyclooxygenase-2 (COX-2), and increased activities of antioxidant enzyme including superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) in serum, levels of pro-angiogenic cytokines such as vascular endothelial growth factor (VEGF) and intercellular adhesion molecule (ICAM-1), and expression of VEGF, FGF-2, p-ERK, and p-Akt protein in granulation.

Conclusions

The results of the present study suggested that the fusion protein accelerated wound healing by improving anti-inflammation and antioxidant, and increasing angiogenesis in granulation tissues of diabetic rats.

Novel nano-insulin formulation modulates cytokine secretion and remodeling to accelerate diabetic wound healing

Little is known about insulin's wound healing capability in normal as well as diabetic conditions. We here report specific interaction of silver nanoparticles (AgNPs) with insulin by making a ~2 nm thick coat around the AgNPs and its potent wound healing efficacy. Characterization of the interaction of human insulin with silver nanoparticles showed confirmed alteration of amide-I in insulin whereas amide-II and III remained unaltered. Further, nanoparticles protein interaction kinetics showed spontaneous interaction at physiological temperature with ΔG, ΔS, Ea and Ka values -7.48, 0.076, 3.84 kcal mol^-1 and 6 × 10⁵ s^-1 respectively. Insulin loaded AgNPs (IAgNPs) showed significant improvement in healing activity in vitro (HEKa cells) and in vivo (Wister Rats) in comparison with the control in both normal and diabetic conditions. The underlying mechanism was attributed to a regulation of the balance between pro (IL-6, TNFα) and anti-inflammatory cytokines (IL-10) at the wound site to promote faster wound remodeling.

Vascular diseases in the mature patient

Aging results in both anatomic and physiologic changes in the skin's structure and vascular system. These vascular changes result in a wide array of dermatologic findings, ranging from the benign to the highly morbid. Herein, we review the impact of both intrinsic and common extrinsic factors of aging on cutaneous vasculature and highlight the manifestations of microvascular, venous, arterial, lymphatic, and neuropathic alterations in the geriatric population.

Bacteriological Profile of Diabetic Foot Ulcer with Special Reference to Drug-resistant Strains in a Tertiary Care Center in North-East India

AIM

This study was carried out to determine the bacteriological profile of infected diabetic foot ulcers (DFUs) and the antibiotic resistance pattern from the isolates. An attempt was made to suggest an empiric antibiotic regimen to treat such patients.

MATERIALS AND METHODS

Tissue samples were collected from 150 patients between February 2015 and January 2016 with DFUs under aseptic precautions and they were processed as per the Clinical and Laboratory Standards Institute guidelines.

RESULTS

A total of 185 bacterial isolates were obtained from 150 persons with diabetic and with foot ulcers. The age group of these persons ranged from 35 to 80 years and the maximum number of persons with DFUs was in the age group of 60-65 years. Among the isolates, Gram-negative bacilli were isolated in 112/185 (61%) and Gram-positive cocci in 73/185 (39%) cases. The most common isolate was Staphylococcus spp. 46 (25%), followed by Escherichia coli (20%) and Enterococcus spp. (15%). The antibiotic sensitivity profile of the bacteria was also studied. Among the isolates, 59/112 (53%) of the Gram-negative bacilli were extended spectrum beta-lactamase producers, 19/46 (41%) were methicillin-resistant Staphylococcus aureus, and 5/27 (19%) were vancomycin-resistant Enterococcus.

CONCLUSIONS

This study showed a preponderance of multidrug-resistant strains among the isolates from the DFUs. Knowledge on the antibiotic sensitivity pattern of the isolates will be helpful in determining the drugs for the empirical treatment of diabetic ulcers. Thus, indiscriminate use of antibiotics and chances of subsequent development of antibiotic resistance can also be reduced.

Use of three-dimensional digital image correlation to evaluate mechanical response of prosthetic systems

BACKGROUND AND AIM

The need of comfortable and safe prosthetic systems is an important challenge for both prosthetists and engineers. The aim of this technical note is to demonstrate the use of three-dimensional digital image correlation to evaluate mechanical response of two prosthetic systems under real patient dynamic loads.

TECHNIQUE

This note describes the use of three-dimensional digital image correlation method to obtain full-field strain and displacement measurements on the surface of two lower limb prostheses for Chopart amputation. It outlines key points of the measurement protocol and illustrates the analysis of critical regions using data obtained on specific points of interest.

DISCUSSION

The results show that the use of three-dimensional digital image correlation can be a tool for the prosthetist to optimize the prosthesis considering features related to the material and design, in order to bear with real patient-specific load conditions. Clinical relevance Three-dimensional digital image correlation can support decision-making on new designs and materials for prosthetics based on quantitative data. Better understanding of mechanical response could also assist prescription for appropriate prosthetic systems.

The amputation prevention initiative

BACKGROUND

The Amputation Prevention Initiative is a project conducted jointly by the Massachusetts Public Health Association and the Massachusetts Podiatric Medical Society that seeks to study methods to reduce nontraumatic lower-extremity amputations from diabetes.

METHODS

To determine the rate of diabetes-related lower-extremity amputations in Massachusetts and identify the groups most at risk, hospital billing and discharge data were analyzed. To examine the components of the diabetic foot examination routinely performed by general practitioners, surveys were conducted in conjunction with physician meetings in Massachusetts (n = 149) and in six other states (n = 490).

RESULTS

The average age-adjusted number of diabetes-related lower-extremity amputations in 2004 was 30.8 per 100,000 and 5.3 per 1,000 diabetic patients in MA, with high-risk groups being identified as men and black individuals. Among the general practitioners surveyed in Massachusetts, only 2.01% reported routinely conducting all four key components of the diabetic foot examination, with 28.86% reporting not performing any components.

CONCLUSIONS

These findings suggest that many general practitioners may be failing to perform the major components of the diabetic foot examination believed to prevent foot ulcers and lower-extremity amputations.

Heme Oxygenase-1 Promotes Delayed Wound Healing in Diabetic Rats

Diabetic ulcers are one of the most serious and costly chronic complications for diabetic patients. Hyperglycemia-induced oxidative stress may play an important role in diabetes and its complications. The aim of the study was to explore the effect of heme oxygenase-1 on wound closure in diabetic rats. Diabetic wound model was prepared by making an incision with full thickness in STZ-induced diabetic rats. Wounds from diabetic rats were treated with 10% hemin ointment for 21 days. Increase of HO-1 protein expression enhanced anti-inflammation and antioxidant in diabetic rats. Furthermore, HO-1 increased the levels of VEGF and ICAM-1 and expressions of CBS and CSE protein. In summary, HO-1 promoted the wound closure by augmenting anti-inflammation, antioxidant, and angiogenesis in diabetic rats.

A Comparison of Tissue versus Swab Culturing of Infected Diabetic Foot Wounds

Objective. To compare the efficacy of swabbing versus tissue biopsy for microbiological diagnosis of diabetic foot infection. Methods. This was a prospective trial. Fifty-six patients with diabetic foot infection were divided into the following 3 groups according to the PEDIS grading system: grade 2 (n = 10), grade 3 (n = 29), and grade 4 (n = 17). Two specimens were collected from each wound for microbial culturing after debridement, including a superficial swab and a deep tissue punch biopsy specimen. Results. Swab culturing identified all of the microorganisms isolated from the corresponding deep tissue specimens in 9/10 of grade 2 wounds (90.0%), and this proportion decreased to 12/29 (41.4%) and 7/17 (41.2%) for grades 3 and 4 wounds, respectively (p = 0.02). Moreover, the sensitivity for identifying Gram-negative bacteria, such as E. coli and Citrobacter, by swabbing was low (33.3%). In addition, some Gram-negative bacteria, such as Serratia and Ralstonia pickettii, were isolated from deep tissues but not from swabs. Conclusions. Swab culturing may be reliable for identification of pathogens in diabetic foot wounds classified as grade 2. However, it is advisable to culture deep tissue specimens for wounds of grade ≥3 because swab culturing is associated with a high risk of missing pathogens, especially Gram-negative bacteria.

Hyperglycemia inhibits complement-mediated immunological control of S. aureus in a rat model of peritonitis

Hyperglycemia from diabetes is associated with increased risk of infection from S. aureus and increased severity of illness. Previous work in our laboratory demonstrated that elevated glucose (>6 mM) dramatically inhibited S. aureus-initiated complement-mediated immune effectors. Here we report in vivo studies evaluating the extent to which a hyperglycemic environment alters complement-mediated control of S. aureus infection in a rat peritonitis model. Rats were treated with streptozocin to induce diabetes or sham-treated and then inoculated i.p. with S. aureus. Rats were euthanized and had peritoneal lavage at 2 or 24 hours after infection to evaluate early and late complement-mediated effects. Hyperglycemia decreased the influx of IgG and complement components into the peritoneum in response to S. aureus infection and decreased anaphylatoxin generation. Hyperglycemia decreased C4-fragment and C3-fragment opsonization of S. aureus recovered in peritoneal fluids, compared with euglycemic or insulin-rescued rats. Hyperglycemic rats showed decreased phagocytosis efficiency compared with euglycemic rats, which correlated inversely with bacterial survival. These results suggest that hyperglycemia inhibited humoral effector recruitment, anaphylatoxin generation, and complement-mediated opsonization of S. aureus, suggesting that hyperglycemic inhibition of complement effectors may contribute to the increased risk and severity of S. aureus infections in diabetic patients.

Phase 3 study comparing tigecycline and ertapenem in patients with diabetic foot infections with and without osteomyelitis

A phase 3, randomized, double-blind trial was conducted in subjects with diabetic foot infections without osteomyelitis (primary study) or with osteomyelitis (substudy) to determine the efficacy and safety of parenteral (intravenous [iv]) tigecycline (150 mg once-daily) versus 1 g once-daily iv ertapenem ± vancomycin. Among 944 subjects in the primary study who received ≥1 dose of study drug, >85% had type 2 diabetes; ~90% had Perfusion, Extent, Depth/tissue loss, Infection, and Sensation infection grade 2 or 3; and ~20% reported prior antibiotic failure. For the clinically evaluable population at test-of-cure, 77.5% of tigecycline- and 82.5% of ertapenem ± vancomycin-treated subjects were cured. Corresponding rates for the clinical modified intent-to-treat population were 71.4% and 77.9%, respectively. Clinical cure rates in the substudy were low (<36%) for a subset of tigecycline-treated subjects with osteomyelitis. Nausea and vomiting occurred significantly more often after tigecycline treatment (P = 0.003 and P < 0.001, respectively), resulting in significantly higher discontinuation rates in the primary study (nausea P = 0.007, vomiting P < 0.001). In the primary study, tigecycline did not meet criteria for noninferiority compared with ertapenem ± vancomycin in the treatment of subjects with diabetic foot infections.

Patient care and management: reduced skin integrity of the foot

The development and deterioration of pressure ulcers are a frequent occurrence across all healthcare settings and specialties, posing daily challenges to the healthcare worker and unnecessary suffering to the patient. Reduced skin integrity occurs within those patients deemed high risk, particularly to the vulnerable areas such as the heel and ankle (American Physical Therapy Association (APTA), 1996). The incidence of pressure ulcers, alongside diabetes, vascular insufficiency and obesity, is on the increase, posing additional demands on current clinical resources; specialist clinics, debridement therapies and appropriate dressing management regimes. This article will focus on the heel and ankle in regards to reduced skin integrity and the positive introduction of an innovative dressing product as an adjunct to the overall care and management of this patient group.

Diabetic musculoskeletal complications and their imaging mimics

Diabetes mellitus is increasingly prevalent and results in various clinically important musculoskeletal disorders affecting the limbs, feet, and spine as well as in widely recognized end-organ complications such as neuropathy, nephropathy, and retinopathy. Diabetic muscle ischemia-a self-limited disorder-may be confused with infectious or inflammatory myositis, venous thrombosis, or compartment syndrome. The absence of fever and leukocytosis, combined with the presence of bilaterally distributed lesions in multiple and often noncontiguous muscles in the legs, including the thighs, is suggestive of ischemia; by contrast, the presence of well-defined intramuscular abscesses with rimlike enhancement favors a diagnosis of infectious pyomyositis. In the diabetic foot, an ulcer, sinus tract, or abscess with an adjacent region of abnormal signal intensity in bone marrow favors the diagnosis of pedal osteomyelitis over that of neuropathic arthropathy. Contrast material-enhanced magnetic resonance imaging is important when planning the treatment of foot infections in diabetic patients because it allows the differentiation of viable tissue from necrotic regions that require surgical débridement in addition to antibiotic therapy. Subtraction images are particularly useful for visualizing nonviable tissue. Dialysis-associated spondyloarthropathy characteristically occurs in diabetic patients with a long history of hemodialysis. Intervertebral disk space narrowing without T2 signal hyperintensity, extensive endplate erosions without endplate remodeling, and facet joint involvement are suggestive of spondyloarthropathy instead of infectious diskitis or degenerative disk disease. Although the clinical features of these conditions may overlap, knowledge of the patient's medical history, coupled with recognition of key imaging characteristics, allows the radiologist to make a prompt and correct diagnosis that leads to appropriate management.

Profile of microvascular disease in type 2 diabetes in a tertiary health care hospital in India

Background:

Diabetes mellitus (DM) is a metabolic disorder complicated by microvascular and macrovascular diseases. The clinical profile of these complications has not been adequately studied in many tertiary health care centers in India.

Aim:

The authors studied the clinical profile of microvascular diabetes complications [peripheral sensory neuropathy (PSN), diabetic retinopathy (DR), nephropathy] in patients attending a tertiary care hospital in India.

Subjects and Methods:

In this cross-sectional study, patients (n = 1529) with type 2 diabetes mellitus (T2DM) were studied for the presence of complications. PSN was diagnosed when the vibration perception threshold of big toe was >25 V. Retinopathy was diagnosed using direct ophthalmoscopy (presence of microaneurysms, exudates, and hemorrhages), and nephropathy with microalbuminuria (≥30 mg/l albumin in a spot urine sample) or low creatinine clearance (<90 ml/min) using Cockcroft-Gault formula.

Results:

PSN was present in 37% (565/1529), nephropathy in 20% (297/1529), and retinopathy in 17% (256/1529) of the study population. Microvascular complications are seen in 48% (734/1529) patients of the study population. Increasing age (P < 0.001), long duration of diabetes (P < 0.001), and higher HbA1c (P = 0.036) were the common risk factors for all complications. Hypertriglyceridemia (P = 0.016) and low body weight (P = 0.039) predisposed to retinopathy over other microangiopathies. Overall, nephropathy was associated strongly with retinopathy (P = 0.015).

Conclusions:

The data showed that neuropathy was the most common microangiopathy and coexisted with other complications in many patients. Old age, long duration of disease, and poor glycemic control are the common risk factors for microvascular complications.

Determination of the augmentation effects of hyaluronic acid on different heel structures in amputated lower limbs of diabetic patients using ultrasound elastography

This study measured tissue properties of different anatomies of heels in amputated lower limbs of diabetic patients before and after hyaluronic acid (HA) or normal saline (NS) injections. Seven amputated lower limbs from six diabetic patients constituted the experimental group and one amputated lower limb from a diabetic patient served as the control. The limbs were placed in a fixation platform. A 5-12 MHz linear-array ultrasound transducer controlled by a stepping motor was used to load and unload tested heels. The loading-unloading velocity was 6 mm/s and the maximum loading stress was 178 kPa. Loading-unloading tests were performed before and after 1 mL HA injections into heels in the experimental group. The control limb underwent the same test before and after 1 mL NS injection. The unloaded thickness and Young's modulus of the macrochambers, microchambers and heel pads were determined before and after the interventions. The unloaded thickness of the macrochambers and the heel pad increased significantly (p = 0.012) after HA injection. The Young's modulus of the macrochambers decreased nonsignificantly after HA injections. Similar thickness and tissue stiffness changes were observed in the control limb. The baseline heel-pad energy dissipation ratio (EDR(hp)) was 81.3 ± 1.3% and decreased significantly (p = 0.012) to 73.1 ± 1.7% after HA injections. The EDR(hp) in the control increased after NS injection. Histologic examinations revealed localized HA accumulation in the macrochambers with an extension into the adjacent fibrous septa. Injection of HA can increase tissue thickness and enhance heel-pad tissue resilience.

Hyperglycemic conditions inhibit C3-mediated immunologic control of Staphylococcus aureus

BACKGROUND

Diabetic patients are at increased risk for bacterial infections; these studies provide new insight into the role of the host defense complement system in controlling bacterial pathogens in hyperglycemic environments.

METHODS

The interactions of complement C3 with bacteria in elevated glucose were assayed for complement activation to opsonic forms, phagocytosis and bacterial killing. C3 was analyzed in euglycemic and hyperglycemic conditions by mass spectrometry to measure glycation and structural differences.

RESULTS

Elevated glucose inhibited S. aureus activation of C3 and deposition of C3b and iC3b on the bacterial surface. S. aureus-generated C5a and serum-mediated phagocytosis by neutrophils were both decreased in elevated glucose conditions. Interestingly, elevated glucose increased the binding of unactivated C3 to S. aureus, which was reversible on return to normal glucose concentrations. In a model of polymicrobial infection, S. aureus in elevated glucose conditions depleted C3 from serum resulting in decreased complement-mediated killing of E. coli. To investigate the effect of differing glucose concentration on C3 structure and glycation, purified C3 incubated with varying glucose concentrations was analyzed by mass spectrometry. Glycation was limited to the same three lysine residues in both euglycemic and hyperglycemic conditions over one hour, thus glycation could not account for observed changes between glucose conditions. However, surface labeling of C3 with sulfo-NHS-biotin showed significant changes in the surface availability of seven lysine residues in response to increasing glucose concentrations. These results suggest that the tertiary structure of C3 changes in response to hyperglycemic conditions leading to an altered interaction of C3 with bacterial pathogens.

CONCLUSIONS

These results demonstrate that hyperglycemic conditions inhibit C3-mediated complement effectors important in the immunological control of S. aureus. Mass spectrometric analysis reveals that the glycation state of C3 is the same regardless of glucose concentration over a one-hour time period. However, in conditions of elevated glucose C3 appears to undergo structural changes.

Diabetic heel ulcer in the Sudan: determinants of outcome

Heel ulceration, on average, costs 1.5 times more than metatarsal ulceration. The aim of this study was to analyze the determinant factors of healing in diabetic patients with heel ulcers and the late outcomes at Jabir Abu Eliz Diabetic Centre Khartoum, Khartoum, Sudan. Data were collected prospectively for 96 of 100 diabetic patients presenting with heel ulcers at the Jabir Abu Eliz Diabetic Centre Khartoum from May 2003 to January 2005. Late outcome was assessed 3 years later (February 2008). Heeling was achieved in one half of the patients (n = 48). In the remaining 48 patients, 22 ended with major lower extremity amputation and 22 were still receiving wound care. A total of 8 patients died, 4 in each group, the healed and unhealed. The most significant determinants of healing using a logistic multivariate regression model, 95% confidence intervals, and odds ratios included a shorter duration of diabetes (p < .009), adequate lower limb perfusion (p < .043), and a superficial foot ulcer (p < .012). Three years later, of the 88 patients who could be traced, 78 were alive and 59 had healed ulcers (7 had died of unrelated causes and 3 of diabetic-related complications), and no additional lower extremity amputation was recorded. Mortality in the series was 18 patients, of whom 14 had undergone a previous lower extremity amputation. Superficial heel ulcers in diabetic patients with a short history of diabetes and with good limb circulation are more likely to heal within an average duration of 25 weeks. At 3 years of follow-up, 75% showed a favorable outcome for ulcer healing, and 22 patients underwent lower extremity amputation (25%), of whom 14 were dead within 3 years.

Validating the probe-to-bone test and other tests for diagnosing chronic osteomyelitis in the diabetic foot

OBJECTIVE

To compare the diagnostic characteristics of tests used for a prompt diagnosis of chronic osteomyelitis in the diabetic foot, using bone histology as the criterion standard. The tests assessed were probe-to-bone (PTB), clinical signs of infection, radiography signs of osteomyelitis, and ulcer specimen culture.

RESEARCH DESIGN AND METHODS

A prospective study was performed on patients with foot ulcers referred to our diabetic foot clinic. Ulcer infection was diagnosed by recording clinical signs of infection and taking specimens for culture. The presumptive diagnosis of osteomyelitis was based on these results and the findings of a plain X-ray and PTB test. All patients with a clinical suspicion of bone infection were subjected to surgical treatment of the affected bone. During surgery, bone specimens were obtained for a histological diagnosis of osteomyelitis.

RESULTS

Over 2.5 years, 210 foot lesions were consecutively examined and 132 of these wounds with clinical suspicion of infection selected as the study sample. Of these, 105 (79.5%) lesions were diagnosed as osteomyelitis. Among the tests compared, the best results were yielded by the PTB test including an efficiency of 94%, sensitivity of 98%, specificity of 78%, positive predictive value of 95%, and negative predictive value of 91% (P < 0.001, κ 0.803); the positive likelihood ratio was 4.41, and the negative likelihood ratio was 0.02 (95% CI).

CONCLUSIONS

In our outpatient population with a high prevalence of osteomyelitis, the PTB test was of greatest diagnostic value, especially for neuropathic ulcers, and proved to be efficient for detecting osteomyelitis in the diabetic foot.

Preserving functional capacity as opposed to tissue preservation in the diabetic patient: a single institution experience

The authors performed a retrospective review of prospectively collected data of all diabetic patients who underwent transmetatarsal amputation (TMA) for toe gangrene or neuropathic ulceration from May 2006 to June 2009. Twenty-nine TMAs were performed in diabetic patients during the study period, including 24 men and 5 women with a mean +/- SD age of 66.3 +/- 7.5 years. The indications for TMA were gangrene of > or = 2 digits in 12 patients (41%) and neuropathic ulceration with underlying osteomyelitis or abscess and a concomitant dysfunctional forefoot in 17 patients (59%). Of the 12 patients who presented with toe gangrene, 7 (58%) underwent endovascular intervention and 5 (42%) underwent open vascular bypass. Equinus contracture was present in 27 patients (93%), and 26 (96%) of these patients underwent tendo-Achilles lengthening or gastrocnemius recession. Correction of equinus contracture was not performed in 1 patient as it was deemed not feasible. Forefoot varus deformity was present in 22 (76%) patients, and balancing was performed in 17 of these patients (77%) with skeletal stabilization or tendon transfer. Balancing was not performed in the remaining patients as it was not necessary or not feasible. Sixteen patients (55%) healed primarily and 5 patients (17%) developed minor wound separation that healed via secondary intention. An additional 4 patients were able to maintain functional revision procedures confined to the foot (1 TMA revision, 3 Chopart amputations). Three patients (10%) required below-knee amputation, and there were 2 deaths (7%) during the time period. Functional amputation confined to the foot was achieved in 86% of ambulatory diabetic patients. These results support a more aggressive initial approach in ambulatory diabetic patients with multiple digital ulcerations, allowing this patient population to remain functional and avoid multiple reoperations and ultimately major amputation.

Plasma thrombin-activatable fibrinolysis inhibitor (TAFI) antigen levels in diabetic foot ulcers

Plasma TAFI may participate in arterial thrombosis in cardiovascular diseases (CVD) and may be involved in the mechanism of vascular endothelial damage in diabetic patients. The aim of this study was to investigate the association of plasma TAFI antigen level in the development of diabetic foot ulcer in Type 2 diabetes. The TAFI antigen levels were determined in 50 patients with diabetic foot ulcers and 34 patients without diabetic foot ulcers and 25 healthy individuals. We measured TAFIa/ai antigen in plasma samples with a commercially available ELISA Kit. Diabetic foot ulcer group and diabetic group were similar in terms of mean age and sex distribution. Diabetes duration, retinopathy, neuropathy, macrovascular disease and infection were related to diabetic foot ulcers. HbA1c, HDL-cholesterol and Folic Acid levels were decreased in the diabetic foot ulcer group. TAFI levels were 99.44 ± 55.94% in control group, 135.21 ± 61.05% in diabetic foot ulcer group, 136.75 ± 59.38% in diabetic group and was statistically different (P < 0.05). But no difference was seen in TAFI levels between the diabetic foot ulcer group and diabetic group (P > 0.05). No significant difference in plasma TAFI levels were seen between diabetic foot ulcer stages. TAFI antigen levels are increased in Type 2 diabetic patients, but are not related to diabetic foot ulcer development.

Fatores preditivos da marcha em pacientes diabéticos neuropático e não neuropáticos

OBJETIVO: Analisar a amplitude de movimento do tornozelo e as forças de reação vertical do solo envolvidas na marcha de pacientes portadores de diabetes com e sem neuropatia periférica. CASUÍSTICA E MÉTODO: 36 indivíduos divididos em três grupos: Controle - GC: 10 indivíduos sem diabetes, Diabetes - GD: 10 indivíduos portadores de diabetes sem neuropatia periférica e Neuropatia - GDN: 16 indivíduos portadores de diabetes e neuropatia diabética periférica. Foi realizada análise da marcha - AMTI® OR6/6, e da amplitude de movimento articular tíbio-társica - Sistema Vicom 640® - de todos os participantes. RESULTADOS: O primeiro e segundo pico de força vertical de reação do solo são maiores no grupo Neuropatia e a amplitude de movimento articular do tornozelo é menor nos grupos Diabetes e Neuropatia. CONCLUSÃO: A amplitude de movimento da articulação tíbio-társica está diminuida nos diabetéticos, independente da presença ou ausência de neuropatia periférica, e os diabéticos com neuropatia periférica, apresentaram aumento no primeiro e no segundo pico da força de reação vertical do solo durante a marcha.

Diabetic effects on microchambers and macrochambers tissue properties in human heel pads

BACKGROUND

The study attempted to highlight the differences of mechanical properties in microchambers and macrochambers between patients with type 2 diabetes mellitus and age-matched healthy volunteers.

METHODS

A total of 29 heels in 18 diabetic patients and 28 heels in 16 age-matched healthy participants were examined by a loading device consisting of a 10-MHz compact linear-array ultrasound transducer, a Plexiglas cylinder, and a load cell. Subjects in both groups were on average about 55 years old with a body mass index of approximately 25 kg/m(2). A stepping motor was used to progressively load the transducer on the tested heels at a velocity of 6mm/s from zero to the maximum stress of 78 kPa. Unloaded thickness, strain, and elastic modulus in microchambers, macrochambers and heel pads were measured.

FINDINGS

Microchambers strain in diabetic patients was significantly greater than that in healthy subjects (0.291 (SD 0.14) vs. 0.104 (SD 0.057); P<0.001). Macrochambers strain in diabetic patients was significantly less than that in healthy subjects (0.355 (SD 0.098) vs. 0.450 (SD 0.092); P=0.001). Microchambers stiffness in diabetic patients was significantly less than that in healthy persons (393 (SD 371)kPa vs. 1140 (SD 931)kPa; P<0.001). Macrochambers stiffness in diabetic patients was significantly greater than that in healthy persons (239 (SD 77)kPa vs. 181 (SD 42)kPa; P=0.001).

INTERPRETATION

Heel pad tissue properties are altered heterogeneously in people with diabetes. Increased macrochambers but decreased microchambers stiffness may cause diminished cushioning capacities in diabetic heels.

Percutaneous flexor tenotomy for treatment of neuropathic toe ulceration secondary to toe contracture in persons with diabetes: a systematic review

Percutaneous flexor tenotomy has been proposed for treatment of neuropathic toe ulcerations secondary to toe contracture in persons with diabetes who have failed ongoing local wound care measures due to the perceived safety and efficacy. Because this patient population comprises a substantial proportion of the authors' practice, we undertook a systematic review of electronic databases and other relevant sources to identify material relating to the use of percutaneous flexor tenotomy for the treatment of neuropathic toe ulcerations secondary to toe contracture deformities in persons with diabetes. Information from peer-reviewed journals, as well as that from non-peer-reviewed publications, abstracts and posters, textbooks, and unpublished works, was considered. In an effort to procure the highest-quality studies available, studies were eligible for inclusion only if they involved consecutively enrolled patients undergoing the same percutaneous surgical treatment, evaluated patients at a mean follow-up of > or =12 months' duration, and included details of complications. Two studies were identified that met the inclusion criteria, both of which were retrospective case series of relatively poor methodological quality. Rather than providing strong evidence for or against the use of percutaneous flexor tenotomy for the treatment of neuropathic toe ulceration secondary to toe contracture in persons with diabetes, the results of this systematic review make clear the need for methodologically sound prospective cohort studies and randomized controlled trials that focus on the use of this form of surgical intervention.

LEVEL OF EVIDENCE

1.

A 1-piece shape-metal nitinol intramedullary internal fixation device for arthrodesis of the proximal interphalangeal joint in neuropathic patients with diabetes

A common complication associated with diabetes is the development of a rigid structural lesser toe contracture, which, when combined with peripheral sensory neuropathy, can lead to ulceration, infection, and amputation. Surgical correction of lesser toe contractures in persons with diabetes has been advocated to decrease the potential for ulceration and amputation. Lesser toe proximal interphalangeal joint arthrodesis employing myriad joint preparation and fixation methods is commonly performed to correct a rigid structural toe contracture. The author performed a retrospective, observational, cohort study involving 10 patients (30 toes) with diabetes, dense peripheral neuropathy, and rigid structural toe contracture treated with a 1-piece shape-memory Nitinol intramedullary internal fixation device for arthrodesis of the proximal interphalangeal joint. Successful fusion was achieved in 28 of 30 toes (93%), with a stable nonunion achieved in the remainder. Complications that arose occurred early in the author's experience with this implant and consisted of secondary contracture of the distal interphalangeal joint (23%), displaced fixation (13%), and malunion (7%). No patient developed ulceration, and no additional surgery has been required to date. When properly performed, the use of this implant for arthrodesis of the proximal interphalangeal joint in neuropathic patients with diabetes appears safe and reliable.

Peroneus longus recession

Correction of the plantarflexed first ray as a result of peroneus longus musculotendinous contracture is commonly achieved through dorsiflexory osteotomy at the base of the first metatarsal or lengthening of the peroneus longus tendon at the lateral aspect of the hindfoot or fibular malleolus. In this techniques report, the author describes peroneus longus recession in the distal aspect of the lower leg based on topographic anatomical landmarks. This procedure can be used to correct soft tissue contracture of the peroneus longus musculotendinous unit.

Tibialis posterior recession

The equinocavovarus deformity that results from tibialis posterior musculotendinous contracture poses a treatment challenge that has few reliable conservative or surgical remedies. In this techniques report, the author describes a tibialis posterior recession procedure that uses the sequential use of topographic anatomical landmarks, which can be useful in correcting contracture of the tibialis posterior musculotendinous unit.

Wound complications

This article discusses postoperative wound complications in detail, including host factors that predispose the patient to nonhealing, technical factors in surgery that can reduce the likelihood of infection and dehiscence, and recommendations for postoperative management that can prevent wound healing problems. This discussion includes the treatment of wound complications, ranging from local wound care to various wound coverage options.

Minimum-incision ray resection

Ray resection for localized necrosis, infection, and osteomyelitis is an accepted procedure allowing removal of the diseased toe and metatarsal. The traditional approach involves a rather lengthy incision and dissection that can compromise the vascular supply to the remaining forefoot. The use of minimum incision techniques to perform metatarsal ray resection as presented here represents a simple, reliable, and easily reproduced procedure that limits soft-tissue dissection and the associated wound healing-related complications inherent to the traditional approach. Following minimum incision metatarsal ray resection, the resultant defect from the toe amputation can be primarily closed, covered with a split-thickness skin graft, or closed in delayed primary fashion with the use of a mini-external fixation device. The authors present the proper indications and a step-by-step guide for performing minimum incision metatarsal ray resection with and without the supplemental use of mini-external fixation to close the soft-tissue defect about the toe amputation site.

Minimum-incision metatarsal osteotomies

This article focuses on minimal-incision metatarsal osteotomies for treating ulcerative lesions related to hallux valgus deformities and central and fifth metatarsal plantar ulcerations to correct the structural deformity responsible for the ulceration. The authors presented a structured review of the literature regarding complications associated with the use of minimum-incision surgical techniques available for the first, central, and fifth metatarsals and techniques to avoid them. Although a steep learning curve exists with these procedures, the advantage of performing minimum- incision metatarsal osteotomies in high-risk populations allows for rapid and predictable resolution of recalcitrant or recurrent ulcerations through correction of the underlying structural deformity with minimal complications.

Percutaneous reduction and external fixation for foot and ankle fractures

Percutaneous reduction with external fixation is an advanced technique for surgical management in foot and ankle trauma. In the high-risk patient, closed or percutaneous reduction followed by external fixation for reduction and stabilization is a unique alternative to achieve anatomic stabilization without increased physical strain to the patient. The significant advantages of this approach include minimizing damage to the vascular supply, maintaining and preserving a stable soft tissue envelope, and allowing for correction to be performed acutely or adjusted gradually over time. This article provides an overview of closed or percutaneous reduction with limited soft tissue dissection and external fixation stabilization techniques, and their role in foot and ankle trauma for the high-risk patient.

Tenotomy and tendon transfer about the forefoot, midfoot and hindfoot

Tendon lengthening and transfer are essential surgical procedures for every foot and ankle surgeon to master, because they are useful in restoring balance and correcting flexible foot deformities. These techniques are even more useful in treating the high-risk patient, because they involve minimal soft-tissue injury and maximum preservation of vascularity. The primary goal of this article is to supplement the foot and ankle surgeon's options for treating static and dynamic foot deformities in the high-risk patient by discussing useful tendon lengthening and transfer procedures about the forefoot, midfoot, and hindfoot.

Soft-tissue and osseous techniques to balance forefoot and midfoot amputations

Soft-tissue and osseous balancing of forefoot and midfoot amputations is imperative to provide the patient with a stable, durable, and functional residual foot. This article discusses reproducible methods for balancing transmetatarsal and Lisfranc amputations in high-risk patients, with detailed explanations of the recommended surgical techniques. In addition to performing the appropriate procedures for the individual patient, careful attention to the perioperative management of this patient population, with a multidisciplinary approach, is mandatory for long-term success.

Use of a surgical preparation and sterile dressing change during office visit treatment of chronic foot and ankle wounds decreases the incidence of infection and treatment costs

Foot and ankle surgeons work with a patient population burdened by multiple factors that adversely affect wound healing and the ability to combat infection. As a result, many of these patients are seen for treatment of chronic ulcerations on their lower extremities that are highly susceptible to colonization and possible progression to a limb- and/or life-threatening infection. The Limb Preservation Service at the Madigan Army Medical Center hypothesized that implementation of a standardized protocol involving a formal physician-directed surgical preparation of the affected lower extremity and a physician-applied sterile dressing at each outpatient clinic appointment would reduce the incidence of infection, use of systemic antibiosis, and thus the requirement for frequent follow-up office appointments. Initiation of this protocol resulted in the reduction of infection to the extent that antibiotic need was eliminated. The frequency of office visits required for follow-up was also significantly reduced. This is key in treating a patient population in which the financial burden to treat chronic wounds and associated infections represents a large portion of the health care money spent for their medical care.