Prevention of foot ulcers in the at-risk patient with diabetes: a systematic review.

BACKGROUND: Prevention of foot ulcers in patients with diabetes is extremely important to help reduce the enormous burden of foot ulceration on both patient and health resources. A comprehensive analysis of reported interventions is not currently available, but is needed to better inform caregivers about effective prevention. The aim of this systematic review is to investigate the effectiveness of interventions to prevent first and recurrent foot ulcers in persons with diabetes who are at risk for ulceration. METHODS: The available medical scientific literature in PubMed, EMBASE, CINAHL and the Cochrane database was searched for original research studies on preventative interventions. Both controlled and non-controlled studies were selected. Data from controlled studies were assessed for methodological quality by two independent reviewers. RESULTS: From the identified records, a total of 30 controlled studies (of which 19 RCTs) and another 44 non-controlled studies were assessed and described. Few controlled studies, of generally low to moderate quality, were identified on the prevention of a first foot ulcer. For the prevention of recurrent plantar foot ulcers, multiple RCTs with low risk of bias show the benefit for the use of daily foot skin temperature measurements and consequent preventative actions, as well as for therapeutic footwear that demonstrates to relieve plantar pressure and that is worn by the patient. To prevent recurrence, some evidence exists for integrated foot care when it includes a combination of professional foot treatment, therapeutic footwear and patient education; for just a single session of patient education, no evidence exists. Surgical interventions can be effective in selected patients, but the evidence base is small. CONCLUSION: The evidence base to support the use of specific self-management and footwear interventions for the prevention of recurrent plantar foot ulcers is quite strong, but is small for the use of other, sometimes widely applied, interventions and is practically nonexistent for the prevention of a first foot ulcer and non-plantar foot ulcer.

Interventions in the management of infection in the foot in diabetes: a systematic review.

The expert panel on diabetic foot infection (DFI) of the International Working Group on the Diabetic Foot conducted a systematic review seeking all published reports relating to any type of treatment for infection of the foot in persons with diabetes published as of 30 June 2014. This review, conducted with both PubMed and EMBASE, was used to update an earlier one undertaken on 30 June 2010 using the same search string. Eligible publications included those that had outcome measures reported for both a treated and a control population that were managed either at the same time, or as part of a before-and-after case design. We did not include studies that contained only information related to definition or diagnosis, but not treatment, of DFI. The current search identified just seven new articles meeting our criteria that were published since the 33 identified with the previous search, making a total of 40 articles from the world literature. The identified articles included 37 randomised controlled trials (RCTs) and three cohort studies with concurrent controls, and included studies on the use of surgical procedures, topical antiseptics, negative pressure wound therapy and hyperbaric oxygen. Among the studies were 15 RCTs that compared outcomes of treatment with new antibiotic preparations compared with a conventional therapy in the management of skin and soft tissue infection. In addition, 10 RCTs and 1 cohort study compared different treatments for osteomyelitis in the diabetic foot. Results of comparisons of different antibiotic regimens generally demonstrated that newly introduced antibiotic regimens appeared to be as effective as conventional therapy (and also more cost-effective in one study), but one study failed to demonstrate non-inferiority of a new antibiotic compared with that of a standard agent. Overall, the available literature was both limited in both the number of studies and the quality of their design. Thus, our systematic review revealed little evidence upon which to make recommendations for treatment of DFIs. There is a great need for further well-designed trials that will provide robust data upon which to make decisions about the most appropriate treatment of both skin and soft tissue infection and osteomyelitis in diabetic patients.

The microbiome of diabetic foot osteomyelitis.

The purpose of this investigation was to evaluate the diversity of bacteria in diabetic foot osteomyelitis using a 16S rRNA sequencing approach and to compare the results with conventional culture techniques. In this prospective observational study, we obtained 34 bone samples from patients admitted to our hospital with a moderate-severe diabetic foot infection. We analysed the distribution of the 16S rRNA gene sequences in the bone samples, using an Illumina MiSeq Personal Sequencer. We compared the genera that were detected with the cultured pathogens in the bone samples with conventional techniques. In the 23 samples that had positive results with both techniques, Staphylococcus, Corynebacterium, Streptococcus and Propionibacterium spp. were detected in 20, 18, 13 and 11 samples, respectively. Significantly more anaerobes were detected with 16S rRNA sequencing compared to conventional techniques (86.9 % vs. 23.1 %, p = 0.001) and more Gram-positive bacilli were present (78.3 % vs. 3.8 %, p < 0.001). Staphylococcus spp. were identified in all of the sequenced bone samples that were negative with conventional techniques. Mixed genera were present in 83.3 % (5 of 6) of the negative samples. Anaerobic and fastidious organisms may play a more significant role in osteomyelitis than previously reported. Further studies with larger populations are needed in order to fully understand the clinical importance of the microbial diversity of diabetic foot osteomyelitis.

A systematic review of the effectiveness of interventions in the management of infection in the diabetic foot.

The International Working Group on the Diabetic Foot expert panel on infection conducted a systematic review of the published evidence relating to treatment of foot infection in diabetes. Our search of the literature published prior to August 2010 identified 7517 articles, 29 of which fulfilled predefined criteria for detailed data extraction. Four additional eligible papers were identified from other sources. Of the total of 33 studies, 29 were randomized controlled trials, and four were cohort studies. Among 12 studies comparing different antibiotic regimens in the management of skin and soft-tissue infection, none reported a better response with any particular regimen. Of seven studies that compared antibiotic regimens in patients with infection involving both soft tissue and bone, one reported a better clinical outcome in those treated with cefoxitin compared with ampicillin/sulbactam, but the others reported no differences between treatment regimens. In two health economic analyses, there was a small saving using one regimen versus another. No published data support the superiority of any particular route of delivery of systemic antibiotics or clarify the optimal duration of antibiotic therapy in either soft-tissue infection or osteomyelitis. In one non-randomized cohort study, the outcome of treatment of osteomyelitis was better when the antibiotic choice was based on culture of bone specimens as opposed to wound swabs, but this study was not randomized, and the results may have been affected by confounding factors. Results from two studies suggested that early surgical intervention was associated with a significant reduction in major amputation, but the methodological quality of both was low. In two studies, the use of superoxidized water was associated with a better outcome than soap or povidone iodine, but both had a high risk of bias. Studies using granulocyte-colony stimulating factor reported mixed results. There was no improvement in infection outcomes associated with hyperbaric oxygen therapy. No benefit has been reported with any other intervention, and, overall, there are currently no trial data to justify the adoption of any particular therapeutic approach in diabetic patients with infection of either soft tissue or bone of the foot.

Expert opinion on the management of infections in the diabetic foot.

This update of the International Working Group on the Diabetic Foot incorporates some information from a related review of diabetic foot osteomyelitis (DFO) and a systematic review of the management of infection of the diabetic foot. The pathophysiology of these infections is now well understood, and there is a validated system for classifying the severity of infections based on their clinical findings. Diagnosing osteomyelitis remains difficult, but several recent publications have clarified the role of clinical, laboratory and imaging tests. Magnetic resonance imaging has emerged as the most accurate means of diagnosing bone infection, but bone biopsy for culture and histopathology remains the criterion standard. Determining the organisms responsible for a diabetic foot infection via culture of appropriately collected tissue specimens enables clinicians to make optimal antibiotic choices based on culture and sensitivity results. In addition to culture-directed antibiotic therapy, most infections require some surgical intervention, ranging from minor debridement to major resection, amputation or revascularization. Clinicians must also provide proper wound care to ensure healing of the wound. Various adjunctive therapies may benefit some patients, but the data supporting them are weak. If properly treated, most diabetic foot infections can be cured. Providers practising in developing countries, and their patients, face especially challenging situations.

Randomized Controlled Trial Comparing the Effects of Far-Infrared Emitting Ceramic Fabric Shirts and Control Polyester Shirts on Transcutaneous PO2.

Our aim was to confirm earlier studies showing tcPO2 to be higher under clothing made with polyethylene terephalate (PET) fabric containing ceramic particles (CEL) compared to standard PET fabric. In previous studies PET garments were donned first to avoid possible persistent effects from ceramic particles. This study randomized donning sequence to avoid bias. METHODS: Subjects were randomized to don either PET shirts first (PETF n=73) or CEL first (CELF n=80), switching garments after 90 minutes. Skin temperature (ST), arterial oxygen saturation (O2sat), and tcPO2 were measured every 30 minutes. RESULTS: Baseline ST and O2 sat were nearly identical in the two groups. Baseline tcPO2 was modestly higher in the CELF group than with PETF: 66.4 ± 18.9 vs. 63.9 ± 18.8 mmHg (n.s). Independent of donning sequence, tcPO2 measurements 90 minutes after wearing CEL were 6.7% higher than after 90 minutes wearing PET (p<0.0003). Sequence analysis found tcPO2 in PETF subjects to gradually rise before and after switching garments, but tcPO2 fell immediately after switching garments in CELF subjects. PETF baseline O2sat of 98.1 ± 1.3 increased insignificantly after 90 minutes, and then increased further to 98.6 ± 0.8 after wearing CEL ninety minutes (p=0.0001). CELF baseline O2sat of 97.9 ± 1.7 increased to 98.5 ± 1.1 90 minutes after donning CEL (p=0.0002) and fell to 98.3 ± 1.0 ninety minutes after switching to PET (p=0.0033). CONCLUSIONS: The ability of ceramic-embedded fabric to induce higher tcPO2 measurements is not due to sequence bias.

The acutely infected diabetic foot is not adequately evaluated in an inpatient setting.

OBJECTIVE: To evaluate the standard of evaluation and treatment of the infected diabetic foot ulceration at a 551-bed university teaching institution. DESIGN: A retrospective review of a 4-year consecutive sample (1991-1994). POPULATION: Two hundred fifty-five patients who were admitted to a hospital for care of an infected diabetic foot ulceration. Patients were subdivided into the following 4 dichotomous variables: (1) whether the patient underwent a lower-extremity amputation, (2) whether the patient was admitted once or multiple times, (3) whether the patient underwent intraoperative debridement, and (4) whether the patient was admitted to medical or surgical services. RESULTS: All groups that were evaluated had undergone a less than adequate foot examination. Of the admitted patients, 31.4% did not have their pedal pulses documented; 59.7% of the admitted patients were not evaluated for the presence or absence of protective sensation. Nearly 90% of the wounds were not evaluated for involvement of underlying structures, and foot radiographs were not performed in 32.9% of the patients. There were more blood cultures ordered (62.0%) than wound cultures (51.4%). CONCLUSION: The results of this study highlight the need for a systematic, detailed lower-extremity examination for every diabetic patient who is admitted to a hospital, particularly those who are admitted with a primary diagnosis that involves a foot complication.

Choosing a practical screening instrument to identify patients at risk for diabetic foot ulceration.

OBJECTIVE: To evaluate the sensitivity and specificity of 3 sensory perception testing instruments to screen for risk of diabetic foot ulceration. METHODS: This case-control study prospectively measured the degree of peripheral sensory neuropathy in diabetic patients with and without foot ulcers. We enrolled 115 age-matched diabetic patients (40% male) with a case-control ratio of approximately 1:3 (30 cases and 85 controls) from a tertiary care diabetic foot specialty clinic. Cases were defined as individuals who had an existing foot ulceration or a history of a recently (< 4 weeks) healed foot ulceration. Controls were defined as subjects with no foot ulceration history. Using receiver operating characteristic analysis, we evaluated the sensitivity and specificity of 2 commonly used nephropathy assessment tools (vibration perception threshold testing and the Semmes-Weinstein 10-g monofilament wire system) and a 4-question verbal neuropathy score to evaluate for presence of foot ulceration. RESULTS: A vibration perception threshold testing using 25 V and lack of perception at 4 or more sites using the Semmes-Weinstein 10-g monofilament wire system had a significantly higher specificity than neuropathy score used. The neuropathy score was most sensitive when 1 or more answers were affirmative. When modalities were combined, particularly the monofilament wire system plus vibration perception threshold testing and the neuropathy score plus the monofilament wire system, there was a substantial increase in specificity with little or no diminution in sensitivity. CONCLUSIONS: The early detection of peripheral neuropathy or loss of "protective sensation" is paramount to instituting a structured treatment plan to prevent lower extremity amputation. The results of our study suggest that all 3 sensory perception testing instruments are sensitive in identifying patients at risk for ulceration. Combining modalities appears to increase specificity with very little or no diminution in sensitivity.

Practical criteria for screening patients at high risk for diabetic foot ulceration.

BACKGROUND: A comprehensive understanding of clinical risk factors for developing foot ulcerations would help clinicians to categorize patients by their risk status and schedule intervention resources accordingly to prevent amputation. OBJECTIVE: To evaluate risk factors for foot ulcerations among persons with diabetes mellitus. METHOD: We enrolled 225 age-matched patients, 46.7% male, with a ratio of approximately 1:2 cases: controls (76 case-patients and 149 control subjects). Case-patients were defined as subjects who met the enrollment criteria and who had an existing foot ulceration or a recent history of a foot ulceration. Control subjects were defined as subjects with no history of foot ulceration. A stepwise logistic regression model was used for analysis. RESULTS: An elevated plantar pressure (> 65 N/cm2), history of amputation, lengthy duration of diabetes (> 10 years), foot deformities (hallux rigidus or hammer toes), male sex, poor diabetes control (glycosylated hemoglobin > 9%), 1 or more subjective symptoms of neuropathy, and an elevated vibration perception threshold (> 25 V) were significantly associated with foot ulceration. In addition, 59 patients (78%) with ulceration had a rigid deformity directly associated with the site of ulceration. No significant associations were noted between vascular disease, level of formal education, nephropathy, retinopathy, impaired vision, or obesity and foot ulceration on multivariate analysis. CONCLUSIONS: Neuropathy, foot deformity, high plantar pressures, and a history of amputation are significantly associated with the presence of foot ulceration. Although vascular and renal disease may result in delayed wound healing and subsequent amputation, they are not significant risk factors for the development of diabetic foot ulceration.

Effectiveness of the diabetic foot risk classification system of the International Working Group on the Diabetic Foot.

OBJECTIVE: To evaluate the effectiveness of a diabetic foot risk classification system by the International Working Group on the Diabetic Foot to predict clinical outcomes. RESEARCH DESIGN AND METHODS: A total of 225 diabetic patients were initially evaluated as part of a prospective case-control study at the University of Texas Health Science Center at San Antonio. Complete records were available for 213 patients for follow-up evaluation after 29 months. Upon enrollment, subjects were stratified into four risk groups based on the presence of risk factors according to the consensus of the International Working Group on the Diabetic Foot. Group 0 consisted of subjects without neuropathy, group 1 consisted of patients with neuropathy but without deformity or peripheral vascular disease (PVD), group 2 consisted of subjects with neuropathy and deformity or PVD, and group 3 consisted of patients with a history of foot ulceration or a lower-extremity amputation. RESULTS: Upon enrollment, patients in higher-risk groups had longer duration of diabetes, worse glycemic control, vascular and neuropathic variables, and more systemic complications of diabetes. During 3 years of follow-up, ulceration occurred in 5.1, 14.3, 18.8, and 55.8% of the patients in groups 0, 1, 2, and 3, respectively (linear-by-linear association, P < 0.001). All amputations were found in Groups 2 and 3 (3.1 and 20.9%, P < 0.001). CONCLUSIONS: The foot risk classification of the International Working Group on the Diabetic Foot predicts ulceration and amputation and can function as a tool to prevent lower-extremity complications of diabetes.

Increased foot pressures after great toe amputation in diabetes.

OBJECTIVE: To compare peak pressures on the sole of the foot in non-insulin-dependent diabetic patients with isolated, unilateral amputations of the great toe and first metatarsal with the patients' contralateral, intact foot. RESEARCH DESIGN AND METHODS: Eleven patients with a unilateral great toe and partial first metatarsal amputation of at least 6 months duration were evaluated with the F-Scan in-shoe pressure measurement system. Patients were studied in the same brand and style of footwear--a thin, rubber-soled, canvas boat shoe. We compared mean peak plantar foot pressures under the first metatarsal, lesser metatarsals, lesser toes, and heel in feet with and without a great toe amputation using the Wilcoxon's matched pairs signed-rank test. RESULTS: Peak foot pressures were significantly higher under the first metatarsal head (P = 0.046), lesser metatarsal heads (P < 0.001), and toes (P < 0.001) in feet with a great toe amputation compared with the contralateral foot without an amputation. Pressure under the heel was higher on the contralateral foot (P < 0.01). CONCLUSIONS: After a great toe amputation, pressure distribution of the foot is significantly altered. Because preamputation risk factors such as peripheral neuropathy, foot deformity, and limited joint mobility for many of these patients remain unchanged, an increase in foot pressures contributes to an increased risk of reulceration and reamputation in these patients.

The development of foot deformities and ulcers after great toe amputation in diabetes.

OBJECTIVE: Our aim was to compare the prevalence and severity of foot deformities and the development of ulcerations in patients after a great toe amputations. RESEARCH DESIGN AND METHODS: We evaluated the presence of deformities of the toes and metatarsophalangeal joints (MTPJs) in patients with a great toe amputation who had an intact unamputated contralateral foot. The contralateral foot served as the patient's own control. We used a binomial test for paired data to compare the presence of deformity and ulcer formation and Fisher's exact test to compare joint flexibility in toes and MTPJs with foot deformities. RESULTS: There were more deformities of the second (P = 0.012) and third (P = 0.002) toes and lesser MTPJs (P < 0.05) and more rigid deformities of the second (P = 0.002) and third (P = 0.016) toes and second MTPJs (P = 0.035) in feet with great toe amputations. New ulcers were more common in feet that had an amputation (P = 0.002). CONCLUSIONS: We concluded that amputation of the great toe contributes to the development of deformities of the second and third toes and lesser MTPJs and new ulcer formation in patients with diabetes. When deformities were present, the second and third toes and second MTPJ were more severe in feet with a great toe amputation.

Systemic hyperbaric oxygen therapy: lower-extremity wound healing and the diabetic foot.

OBJECTIVE: To document peer-reviewed medical publications that have reported on hyperbaric oxygen (HBO) therapy as an adjunct to standard lower-extremity wound care, focusing on publications dealing with the diabetic foot. RESEARCH DESIGN AND METHODS: A review of the medical literature was conducted using MEDLINE. Research articles involving HBO treatment and the diabetic foot were critiqued to identify factors that may have been a source of bias. RESULTS: Of the published reports on human studies, seven involved diabetes-related foot pathology. Five of these studies, two of which were randomized, included a control group that did not receive HBO therapy The controlled diabetic foot studies included an average of 28 subjects in the HBO therapy group (range 10-62) and an average of 16.2 subjects in the non-HBO control group (range 5-33). Most of the published reports have several potential sources of bias, including, but not limited to, inadequate evaluation of comorbid conditions relevant to wound healing, small sample size, and poor documentation of wound size or severity. Four of the seven reports involving the diabetic foot were published by a group of researchers at the University of Milan between 1987 and 1996. CONCLUSIONS: Additional randomized placebo-controlled clinical trials in large diabetic populations would further lend credence to the presumption that HBO therapy improves clinical outcomes. Given the relatively high cost of this treatment modality, perhaps a more acute awareness of the medical literature would reduce the economic burden that HBO therapy imposes on care providers that are financially at risk.

Validation of a diabetic wound classification system. The contribution of depth, infection, and ischemia to risk of amputation.

OBJECTIVE: To validate a wound classification instrument that includes assessment of depth, infection, and ischemia based on the eventual outcome of the wound. RESEARCH DESIGN AND METHODS: We evaluated the medical records of 360 diabetic patients presenting for care of foot wounds at a multidisciplinary tertiary care foot clinic. As per protocol, all patients had a standardized evaluation to assess wound depth, sensory neuropathy, vascular insufficiency, and infection. Patients were assessed at 6 months after their initial evaluation to see whether an amputation had been performed. RESULTS: There was a significant overall trend toward increased prevalence of amputations as wounds increased in both depth (chi 2trend = 143.1, P < 0.001) and stage (chi 2trend = 91.0, P < 0.001). This was true for every subcategory as well with the exception of noninfected, nonischemic ulcers. There were no amputations performed within this stage during the follow-up period. Patients were more than 11 times more likely to receive a midfoot or higher level amputation if their wound probed to bone (18.3 vs. 2.0%, P < 0.001, chi 2 = 31.5, odds ratio (OR) = 11.1, CI = 4.0-30.3). Patients with infection and ischemia were nearly 90 times more likely to receive a midfoot or higher amputation compared with patients in less advanced wound stages (76.5 vs. 3.5%, P < 0.001, chi 2 = 133.5, OR = 89.6, CI = 25-316). CONCLUSIONS: Outcomes deteriorated with increasing grade and stage of wounds when measured using the University of Texas Wound Classification System.

Infected puncture wounds in diabetic and nondiabetic adults.

OBJECTIVE: To evaluate bone and soft tissue pathogens resulting from puncture wounds among diabetic and nondiabetic adults. RESEARCH DESIGN AND METHODS: We used a case-control design to compare bacterial pathogens in diabetic and nondiabetic subjects with foot infections precipitated by puncture injuries. We used ICD-9-CM code E920.8 to identify 77 diabetic and 69 nondiabetic patients admitted to the hospital for infected puncture wounds. We identified surgical bone and soft tissue cultures and number and type of organisms per culture. RESULTS: Nondiabetic subjects had significantly less osteomyelitis (13 vs. 35%, P < 0.01) than diabetic subjects and were infected by fewer organisms. Pseudomonas was the most common cause of osteomyelitis among nondiabetic subjects (P < 0.001). Staphylococcus aureus was more common in diabetic bone (P < 0.001) and soft tissue (P < 0.001) infections. Polymicrobial osteomyelitis was more common in diabetic subjects. There was a longer delay until diabetic subjects received medical treatment compared with nondiabetic subjects (8.7 vs. 5.3 days, P < 0.002). Diabetic subjects were more likely to have neuropathy (P < 0.001) and to have sustained their injuries while barefoot (P < 0.006). CONCLUSIONS: Puncture wounds in diabetic subjects were commonly associated with polymicrobial infections. Pseudomonas was the most common cause of nondiabetic osteomyelitis. These results have implications for differential emergent and chronic treatment of puncture wounds in diabetic versus nondiabetic subjects.

Reducing dynamic foot pressures in high-risk diabetic subjects with foot ulcerations. A comparison of treatments.

OBJECTIVE: To compare the effectiveness of total contact casts, commercially available therapeutic shoes, and removable walking casts to reduce mean peak plantar foot pressures at the site of neuropathic ulcerations in diabetic subjects. RESEARCH DESIGN AND METHODS: We compared the reduction in peak plantar pressures at ulcer sites under the great toe (n = 5), first metatarsal (n = 10), and second through fifth metatarsals (n = 10) using six treatments: total contact casts (TCCs), DH Pressure Relief Walkers (DH), Aircast Pneumatic Walkers, Three D Dura-Steppers (3D), CAM Walkers, and P.W. Minor Xtra Depth shoes. A rubber sole canvas oxford was used to establish baseline pressure values. The canvas oxford could be viewed as a worse-case scenario for this patient population. With the EMED Pedar in-shoe pressure measurement system, data for 40 steps were collected for each treatment. We used Tukey's Studentized Range Test for simultaneous multiple comparisons to compare treatments. RESULTS: DH Pressure Relief Walkers reduced plantar pressures significantly better than other commercially available treatments for ulcers under the first metatarsal, second through fifth metatarsals, and great toe (P < 0.05). There was not a significant difference in mean peak plantar pressures between TCCs and DHs at any of the forefoot ulcer sites. CONCLUSIONS: DH Pressure Relief Walkers were as effective as total contact casts to reduce foot pressures at ulcer sites and may be an effective practical addition in the treatment of foot ulcers.

Reducing plantar pressure in the neuropathic foot. A comparison of footwear.

OBJECTIVE: To compare the effectiveness of therapeutic, comfort, and athletic shoes with and without viscoelastic insoles. RESEARCH DESIGN AND METHODS: We compared pressure reduction at ulcer sites under the hallux (n = 10), first metatarsal (n = 10), and lesser metatarsals (n = 12), using extra-depth, athletic, and comfort shoes with and without viscoelastic insoles. A rubber-soled canvas oxford was used to establish baseline pressure values. RESULTS: When used in conjunction with a viscoelastic insole, all shoe types reduced mean peak plantar pressure better than their non-insoled counterparts (P < 0.05). Consistently, comfort shoes reduced pressure significantly better than both the cross trainers and extra-depth shoes for ulcers under the first and lesser metatarsals (P < 0.05). For each shoe type, the addition of the viscoelastic insole provided a significant reduction in mean peak pressure (P < 0.05). Compared with stock insoles, viscoelastic insoles reduced pressures an additional 5.4-20.1% at ulcer sites. The same trend was also observed at regions of the foot not associated with an ulceration. CONCLUSIONS: When used in conjunction with a viscoelastic insole, both the comfort and athletic cross-trainer shoes studied were as, if not more, effective than commonly prescribed therapeutic shoes in reducing mean peak first and lesser metatarsal pressures. Furthermore, comfort shoes were as effective as therapeutic shoes in reducing pressure under the great toe. Both of these shoe types may be viable options to prevent the development or recurrence of foot ulcers.

Role of neuropathy and high foot pressures in diabetic foot ulceration.

OBJECTIVE: High plantar foot pressures in association with peripheral neuropathy have been ascertained to be important risk factors for ulceration in the diabetic foot. Most studies investigating these parameters have been limited by their size and the homogeneity of study subjects. The objective of this study was therefore to ascertain the risk of ulceration associated with high foot pressures and peripheral neuropathy in a large and diverse diabetic population. RESEARCH DESIGN AND METHODS: We studied a cross-sectional group of 251 diabetic patients of Caucasian (group C) (n=121), black (group B) (n=36), and Hispanic (group H) (n=94) racial origins with an overall age of 58.5+/-12.5 years (range 20-83). There was an equal distribution of men and women across the entire study population. All patients underwent a complete medical history and lower extremity evaluation for neuropathy and foot pressures. Neuropathic parameters were dichotomized (0/1) into two high-risk variables: patients with a vibration perception threshold (VPT) > or =25 V were categorized as HiVPT (n=132) and those with Semmes-Weinstein monofilament tests > or =5.07 were classified as HiSWF (n=190). The mean dynamic foot pressures of three footsteps were measured using the F-scan mat system with patients walking without shoes. Maximum plantar pressures were dichotomized into a high-pressure variable (Pmax6) indicating those subjects with pressures > or =6 kg/cm2 (n=96). A total of 99 patients had a current or prior history of ulceration at baseline. RESULTS: Joint mobility was significantly greater in the Hispanic cohort compared with the other groups at the first metatarsal-phalangeal joint (C 67+/-23 degrees, B 69+/-23 degrees, H 82+/-23 degrees, P=0.000), while the subtalar joint mobility was reduced in the Caucasian group (C 21+/-8 degrees, B 26+/-7 degrees, H 27+/-11 degrees, P=0.000). Maximum plantar foot pressures were significantly higher in the Caucasian group (C 6.7+/-2.9 kg/cm2, B 5.7+/-2.8 kg/cm2, H 4.4+/-1.9 kg/cm2, P=0.000). Univariate logistic regression for Pmax6 on the history of ulceration yielded an odds ratio (OR) of 3.9 (P=0.000). For HiVPT, the OR was 11.7 (P=0.000), and for HiSWF the OR was 9.6 (P=0.000). Controlling for age, diabetes duration, sex, and race (all P < 0.05), multivariate logistic regression yielded the following significant associations with ulceration: Pmax6 (OR=2.1, P=0.002), HiVPT (OR=4.4, P=0.000), and HiSWF (OR=4.1, P=0.000). CONCLUSIONS: We conclude that both high foot pressures (> or =6 kg/cm2) and neuropathy are independently associated with ulceration in a diverse diabetic population, with the latter having the greater magnitude of effect. In black and Hispanic diabetic patients especially, joint mobility and plantar pressures are less predictive of ulceration than in Caucasians.