The impact and outcomes of establishing an integrated interdisciplinary surgical team to care for the diabetic foot.

OBJECTIVE: This study aimed to quantify the impact of an integrated diabetic foot surgical service on outcomes and changes in surgical volume and focus. METHODS: We abstracted registry data from 48 consecutive months at a single institution, evaluating all patients with diabetic foot complications requiring surgery or vascular intervention, and compared outcomes in the 24 months before and after integrating podiatric surgery with vascular surgical limb-salvage service. RESULTS: The service performed 2923 operations; 790 (27.0%) were related to treatment of diabetic foot complications in 374 patients. Of these, 502 were classified as non-vascular diabetic foot surgery and 288 were vascular interventions. Urgent surgery was significantly reduced after team implementation (77.7% vs 48.5%, p < 0.0001; OR = 3.7, 95% CI: 2.4-5.5). The high/low amputation ratio decreased from 0.35 to 0.27 due to an increase in low-level (midfoot) amputations (8.2% vs 26.1%, p < 0.0001; OR = 4.0, 95% CI: 2.0-83.3). A 45.7% reduction in below-knee amputations was realized with a stable above-knee/below-knee amputation ratio (0.73-0.81). One-third of patients required vascular intervention. Vascular reconstructions increased 44.1% following institution of the team. Initial revascularization was endovascular in 70.6% of patients. Repeat endovascular intervention or conversion to open bypass was required in 37.1% of these patients, almost double the reintervention rate of those receiving open bypass first (18.9%). CONCLUSIONS: Interdisciplinary diabetic foot surgery teams may significantly impact surgery type, with greater focus on proactive and preventive, rather than reactive and ablative, procedures. Although endovascular limb-sparing procedures have become increasingly applicable, open bypass remains critical to success.

Diabetic foot infections: A need for innovative assessments.

Foot wounds are the most common diabetes-related cause of hospitalization and frequently result in amputation. Although generally diagnosed clinically based on signs and symptoms of inflammation, empirical antibiotic treatment should be based on tissue cultures until resolution of infection. Advances in molecular detection over the past decade, including rapid chromogenic agar and real-time polymerase chain reaction, have improved diagnostic capabilities. However, chronic wounds may host biofilm bacteria not adequately detected by current microbiological testing. Enhanced DNA testing is required to identify these pathogens as well as evolving and previously underdiagnosed bacteria. Two options, nucleic acid fluorescent in situ hybridization and rDNA sequencing, are on the horizon for clinical use. Wound biofilms also necessitate more complex clinical management including debridement, augmenting host defenses, suppression of biofilms, and wound closure. Adopting these advances in diagnosis and treatment may help with overall prognosis and reduce health care costs.

Skin temperature monitoring reduces the risk for diabetic foot ulceration in high-risk patients.

PURPOSE: To evaluate the effectiveness of home temperature monitoring to reduce the incidence of foot ulcers in high-risk patients with diabetes. METHODS: In this physician-blinded, 18-month randomized controlled trial, 225 subjects with diabetes at high risk for ulceration were assigned to standard therapy (Standard Therapy Group) or dermal thermometry (Dermal Thermometry Group) groups. Both groups received therapeutic footwear, diabetic foot education, regular foot care, and performed a structured foot inspection daily. Dermal Thermometry Group subjects used an infrared skin thermometer to measure temperatures on 6 foot sites twice daily. Temperature differences >4 degrees F between left and right corresponding sites triggered patients to contact the study nurse and reduce activity until temperatures normalized. RESULTS: A total of 8.4% (n=19) subjects ulcerated over the study period. Subjects were one third as likely to ulcerate in the Dermal Thermometry Group compared with the Standard Therapy Group (12.2% vs 4.7%, odds ratio 3.0, 95% confidence interval, 1.0 to 8.5, P=.038). Proportional hazards regression analysis suggested that thermometry intervention was associated with a significantly longer time to ulceration (P=.04), adjusted for elevated foot ulcer classification (International Working Group Risk Factor 3), age, and minority status. Patients that ulcerated had a temperature difference that was 4.8 times greater at the site of ulceration in the week before ulceration than did a random 7 consecutive-day sample of 50 other subjects that did not ulcerate (3.50+/-1.0 vs 0.74+/-0.05, P=.001). CONCLUSIONS: High temperature gradients between feet may predict the onset of neuropathic ulceration and self-monitoring may reduce the risk of ulceration.

Do US veterans wear appropriately sized shoes?: the Veterans Affairs shoe size selection study.

Poorly fitting footwear has frequently been cited as an etiologic factor in the pathway to diabetic foot ulceration. However, we are unaware of any reports in the medical literature specifically measuring shoe size versus foot size in this high-risk population. We assessed the prevalence of poorly fitting footwear in individuals with and without diabetic foot ulceration. We evaluated the shoe size of 440 consecutive patients (94.1% male; mean +/- SD age, 67.2 +/- 12.5 years) presenting to an interdisciplinary teaching clinic. Of this population, 58.4% were diagnosed as having diabetes, and 6.8% had active diabetic foot ulceration. Only 25.5% of the patients were wearing appropriately sized shoes. Individuals with diabetic foot ulceration were 5.1 times more likely to have poorly fitting shoes than those without a wound (93.3% versus 73.2%; odds ratio [OR], 5.1; 95% confidence interval [CI], 1.2-21.9; P = .02). This association was also evident when assessing only the 32.3% of the total population with diabetes and loss of protective sensation (93.3% versus 75.0%; OR, 4.8; 95% CI, 1.1-20.9; P = .04). Poorly fitting shoes seem to be more prevalent in people with diabetic foot wounds than in those without wounds with or without peripheral neuropathy. This implies that appropriate meticulous screening for shoe-foot mismatches may be useful in reducing the risk of lower-extremity ulceration.

Maggot therapy in "lower-extremity hospice" wound care: fewer amputations and more antibiotic-free days.

We sought to assess, in a case-control model, the potential efficacy of maggot debridement therapy in 60 nonambulatory patients (mean +/- SD age, 72.2 +/- 6.8 years) with neuroischemic diabetic foot wounds (University of Texas grade C or D wounds below the malleoli) and peripheral vascular disease. Twenty-seven of these patients (45%) healed during 6 months of review. There was no significant difference in the proportion of patients healing in the maggot debridement therapy versus control group (57% versus 33%). Of patients who healed, time to healing was significantly shorter in the maggot therapy than in the control group (18.5 +/- 4.8 versus 22.4 +/- 4.4 weeks). Approximately one in five patients (22%) underwent a high-level (above-the-foot) amputation. Patients in the control group were three times as likely to undergo amputation (33% versus 10%). Although there was no significant difference in infection prevalence in patients undergoing maggot therapy versus controls (80% versus 60%), there were significantly more antibiotic-free days during follow-up in patients who received maggot therapy (126.8 +/- 30.3 versus 81.9 +/- 42.1 days). Maggot debridement therapy reduces short-term morbidity in nonambulatory patients with diabetic foot wounds.

Cooling the foot to prevent diabetic foot wounds: a proof-of-concept trial.

The etiology of neuropathic diabetic foot wounds can be summarized by the following formula: pressure x cycles of repetitive stress = ulceration. The final pathway to ulceration consists of an inflammatory response, leading to tissue breakdown. Mitigation of this response might reduce the risk of ulceration. This proof-of-concept trial evaluates whether simple cooling of the foot can safely reduce the time to thermal equilibrium after activity. After a 15-min brisk walk, the six nondiabetic volunteers enrolled were randomly assigned to receive either air cooling or a 10-min 55 degrees F cool water bath followed by air cooling. The process was then repeated with the intervention reversed, allowing subjects to serve as their own controls. There was a rise in mean +/- SD skin temperature after 15 min of activity versus preactivity levels (87.8 degrees +/- 3.9 degrees versus 79 degrees +/- 2.2 degrees F; P = .0001). Water cooling immediately brought the foot to a point cooler than preactivity levels for all subjects, whereas air cooling required an average of nearly 17 min to do so. Ten minutes of cooling required a mean +/- SD of 26.2 +/- 5.9 min to warm to preactivity levels. No adverse effects resulted from the intervention. We conclude that cooling the foot may be a safe and effective method of reducing inflammation and may serve as a prophylactic or interventional tool to reduce skin breakdown risk.

Plantar pressure changes using a novel negative pressure wound therapy technique.

This study evaluated changes in pressure imparted to diabetic foot wounds using a novel negative pressure bridging technique coupled with a robust removable cast walker. Ten patients had plantar pressures assessed with and without a bridged negative pressure dressing on the foot. Off-loading was accomplished with a pressure-relief walker. Plantar pressures were recorded using two pressure-measurement systems. The location and value of peak focal pressure (taken from six midgait steps) were recorded at the site of ulceration. Paired analysis revealed a large difference (mean +/- SD, 74.6% +/- 6.0%) between baseline barefoot pressure and pressure within the pressure-relief walker (mean +/- SD, 939.1 +/- 195.1 versus 235.7 +/- 66.1 kPa). There was a mean +/- SD 9.9% +/- 5.6% higher pressure in the combination device compared with the pressure-relief walker alone (mean +/- SD, 258.0 +/- 69.7 versus 235.7 +/- 66.1 kPa). This difference was only 2% of the initial barefoot pressure imparted to the wound. A modified negative pressure dressing coupled with a robust removable cast walker may not impart undue additional stress to the plantar aspect of the foot and may allow patients to retain some degree of freedom (and a potentially reduced length of hospital stay) while still allowing for the beneficial effects of negative pressure wound therapy and sufficient off-loading.

Use of a maggot motility index to evaluate survival of therapeutic larvae.

Maggot debridement therapy is rapidly increasing in popularity at major diabetic foot and wound care centers worldwide. However, we are unaware of specific guidelines on the short-term storage of larvae. We sought to evaluate differences in maggot motility over time in larvae refrigerated versus those stored at room temperature. We also introduce a simple surrogate method for evaluating maggot vitality that may be useful for in vivo studies if validated in future works. We randomly selected ten larvae from the same shipment at ten different times in 9 days. Larvae were placed on a translucent acetate grid, and their total excursion in 30 sec was measured. This was converted into a Maggot Motility Index. In the refrigerated group, the index remained at or above 40 mm/min for approximately 60 hours from baseline, when there was a significant decrease. This same phenomenon occurred during the first 12 hours in the nonrefrigerated group. There were significant differences in motility between refrigerated and nonrefrigerated larvae immediately after baseline until day 8. Larvae are more practical for repeated clinical use if kept refrigerated between applications.

Clinical efficacy of the first metatarsophalangeal joint arthroplasty as a curative procedure for hallux interphalangeal joint wounds in patients with diabetes.

OBJECTIVE: To evaluate the safety and efficacy of first metatarsophalangeal joint arthroplasty compared with standard, nonsurgical management of wounds at the plantar hallux interphalangeal joint in patients with diabetes. RESEARCH DESIGN AND METHODS: We evaluated 41 patients with ulcers classified as University of Texas Grade 1A or 2A at the plantar aspect of the hallux interphalangeal joint using a case-control model [correction]. Case subjects were patients treated with resectional arthroplasty and control subjects received standard nonsurgical care. Both groups received standard off-loading and wound care. Outcomes included time to healing, reulceration, infection, and amputation. RESULTS: The surgery group healed significantly faster than patients in the standard therapy group (standard 67.1 +/- 17.1 versus surgery 24.2 +/- 9.9 days, P = 0.0001), and they had fewer recurrent ulcers (standard 35.0 versus surgery 4.8%, P = 0.02, odds ratio 7.6, 95% CI 1.1-261.7) Both groups had similar rates of infection (standard 38.1 versus surgery 40.0%, P = 0.9) and amputation (standard 10.0 versus surgery 4.8%, P = 0.5). CONCLUSIONS: Results suggest that resectional arthroplasty is a safe and effective procedure to treat wounds of the plantar hallux compared with nonsurgical therapy.

Activity patterns of patients with diabetic foot ulceration: patients with active ulceration may not adhere to a standard pressure off-loading regimen.

OBJECTIVE: To evaluate the activity of patients with diabetic foot ulcerations and their adherence to their pressure off-loading device. RESEARCH DESIGN AND METHODS: We enrolled 20 subjects treated for neuropathic diabetic foot wounds corresponding to University of Texas grade 1 stage A. All were off-loaded using a removable cast walker (RCW). We recorded the total activity (measured in activity steps per day) taken on a waist-worn computerized accelerometer. We subsequently correlated this to activity recorded on an RCW-mounted accelerometer, which was not readily accessible to the patient. RESULTS: There were a mean 1219.1 +/- 821.2 activity units (steps) taken per patient per day. Patients logged significantly more daily activity units with the protective RCW off than with it on (873.7 +/- 828.0 vs. 345.3 +/- 219.1, P = 0.01). This amounts to only 28% of total daily activity recorded while patients were wearing their RCW. Although a total of 30% of the patients in the study recorded more daily activity units while wearing the device, this subset most adherent to their off-loading regimen still only wore the device for a total of 60% of their total daily activity. CONCLUSIONS: Subjects with diabetic foot ulcerations appear to wear their off-loading devices for only a minority of steps taken each day. This may partially explain the poor results reported from many trials of agents designed to help speed the healing of these wounds. Control of this important aspect of care with less easily removable devices may increase the prevalence of healing.