Offloading devices for diabetic foot ulcers (DFU) generally restrict exercise. In addition to traditional health benefits, exercise could benefit DFU by increasing blood flow and acting as thermotherapy. This study functionally evaluated a cycling cleat designed for forefoot DFU.
Fifteen individuals at risk of developing a DFU used a recumbent stationary bicycle to complete one 5-minute cycling bout with the DFU cleat on their study foot and one 5-minute bout without it. Foot stress was evaluated by plantar pressure insoles during cycling. Laser Doppler perfusion monitored blood flow to the hallux. Infrared photographs measured foot temperature before and after each cycling bout.
The specialized cleat significantly reduced forefoot plantar pressure (9.9 kPa versus 62.6 kPa, P < .05) and pressure time integral (15.4 versus 76.4 kPa*sec, P < .05). Irrespective of footwear condition, perfusion to the hallux increased (3.97 ± 1.2 versus 6.9 ± 1.4 tissue perfusion units, P < .05) after exercise. Infrared images revealed no changes in foot temperature.
The specialized cleat allowed participants to exercise with minimal forefoot stress. The observed increase in perfusion suggests that healing might improve if patients with active DFU were to use the cleat. Potential thermotherapy for DFU was not supported by this study. Evaluation of the device among individuals with active DFU is now warranted.
Background: We used a model of lower-extremity ulceration to determine the impact of a podiatric lead limb preservation team on identified relationships among risk factors, predictors of ulceration, amputation, and clinical outcomes of lower-extremity disease in patients with diabetes mellitus.
Methods: A total of 485 patients with diabetes mellitus were randomly selected from the diabetic population and included in this retrospective cohort study. Patients were then stratified into two groups: those who received specialty podiatric medical care and those who did not. Data covering a 5-year period were collected using electronic medical records and chart abstraction to capture detailed treatment characteristics, ulcer status, and surgical outcomes.
Results: Overall, the frequencies of inpatient and outpatient encounters and the durations of hospital stays were significantly greater with increasing wound depth and in the presence of infection. In addition, the overall ulcer incidence was greater in patients with callus (34.3% versus 10.3%, P < .0001) with and without neuropathy (20.4% and 4.1%, P < .0001). Among patients treated in a specialty multidiscipline podiatric medical setting, the proportion of all amputations that were “minor” was significantly increased (33.7% versus 67.3%, P = .0006), and survival was significantly improved (19.5% versus 7.7%, P < .0001).
Conclusions: Early identification of individuals at increased risk for lower-extremity ulceration and subsequent referral for advanced multidiscipline podiatric medical specialty care may decrease rates of ulceration and proximal amputation and improve survival in patients with diabetes mellitus who are at high risk for ulceration and limb loss. (J Am Podiatr Med Assoc 100(4): 235–241, 2010)
The utility of wound debridement has expanded to include the management of all chronic wounds, even in the absence of infection and gross necrosis. Biofilms, metalloproteases on the wound base, and senescent cells at the wound edge irreversibly change the physiologic features of wound healing and contribute to a pathologic, chronic inflammatory environment. The objective of this review is to provide surgeons with a basic understanding of the processes of debridement in the noninfected wound. (J Am Podiatr Med Assoc 100(5): 353–359, 2010)
First-line therapy for diabetic patients presenting with intermittent claudication includes supervised exercise programs to improve walking distance. However, exercise comes with a variety of barriers and may be contraindicated in certain conditions. The aim of this study was to evaluate whether calf muscle electrostimulation improves claudication distance.
A prospective, one-group, pretest-posttest study design was used on 40 participants living with type 2 diabetes mellitus, peripheral artery disease (ankle brachial pressure index, <0.90), and calf muscle claudication. Calf muscle electrostimulation of varying frequencies (1–250 Hz) was prescribed on both limbs for 1-hour daily sessions for 12 consecutive weeks. The absolute claudication distance (ACD) was measured at baseline and after the intervention.
The recruited cohort (30 men and ten women; mean age, 71 years; mean ankle brachial pressure index, 0.70) registered a mean ± SD baseline ACD of 333.71 ± 208 m. After a mean ± SD of 91.68 ± 6.23 days of electrical stimulation, a significant mean ± SD increase of 137 ± 136 m in the ACD (P = .001, Wilcoxon signed rank test) was registered. Improvement was found to be sex independent, but age was negatively correlated with proportion of improvement (r = –0.361; P = .011, Pearson correlation test).
Electrical stimulation of varying frequencies on ischemic calf muscles significantly increased the maximal walking capacity in claudicants with type 2 diabetes. This therapeutic approach should be considered in patients with impaired exercise tolerance or as an adjunct treatment modality.
We sought to develop new recombinant human epidermal growth factor (rhEGF)–containing hydrogels and to investigate their biological activity and therapeutic effects on wound healing in diabetic rats.
Levels of rhEGF released from hydrogels were measured by enzyme-linked immunosorbent assay. The cellular proliferating activity of released rhEGF was evaluated by MTT assay. Fifty-six wounded diabetic rats were randomly divided into four groups with different topical treatment daily. The therapeutic effects were evaluated by wound area measurement, histologic analysis, immunohistochemical assessment of proliferating cell nuclear antigen and B-cell lymphoma/leukemia-2, and Western blotting of EGF receptor.
The rhEGF released from the hydrogel matrix kept its bioactivity on stimulating proliferation of the BALB/c3T3 cell line. Wound closure rates on postoperative day 14 were 75.8% in the negative control group, 82.83% in the group treated with hydrogel matrix, 85.87% in the group treated with rhEGF-containing hydrogel, and 81.18% in the group treated with rhEGF solution. Compared with hydrogel matrix, rhEGF-containing hydrogel had an additional effect on induction of EGF receptor expression (P < .05). Compared with negative controls, protein expression of B-cell lymphoma/leukemia-2 was higher in the rhEGF-containing groups (P < .05). Proliferating cell nuclear antigen was induced at its highest level on day 7 in the rhEGF-containing hydrogel–treated group (P < .05).
These data from in vitro release and diabetic animal models highlight the efficacy of hydrogels as a controlled releasing system for topical application of EGFs. The rhEGF-containing hydrogel we developed holds the merits of prolonged and sustained releasing of bioactive rhEGF and therapeutic potential in enhancing diabetic wound healing. (J Am Podiatr Med Assoc 102(2): 89–98, 2012)
A randomized controlled study of 19 patients with diabetes mellitus (10 men, 9 women) was undertaken to determine the effects of home exercise therapy on joint mobility and plantar pressures. Of the 19 subjects, 9 subjects performed unsupervised active and passive range-of-motion exercises of the joints in their feet. Each subject was evaluated for joint stiffness and peak plantar pressures at the beginning and conclusion of the study. After only 1 month of therapy, a statistically significant average decrease of 4.2% in peak plantar pressures was noted in the subjects performing the range-of-motion exercises. In the control group, an average increase of 4.4% in peak plantar pressures was noted. Although the joint mobility data revealed no statistically significant differences between the groups, there was a trend for a decrease in joint stiffness in the treatment group. The results of this study demonstrate that an unsupervised range-of-motion exercise program can reduce peak plantar pressures in the diabetic foot. Given that high plantar pressures have been linked to diabetic neuropathic ulceration, it may be possible to reduce the risk of such ulceration with this therapy. (J Am Podiatr Med Assoc 92(9): 483-490, 2002)
Background: Diabetic lower-extremity disease is the primary driver of mortality in patients with diabetes. Amputations at the forefoot or ankle preserve limb length, increase function, and, ultimately, reduce deconditioning and mortality compared with higher-level amputations, such as below-the-knee amputations (BKAs). We sought to identify risk factors associated with amputation level to understand barriers to length-preserving amputations (LPAs).
Methods: Diabetic lower-extremity admissions were extracted from the 2012-2014 National Inpatient Survey using ICD-9-CM diagnosis codes. The main outcome was a two-level variable consisting of LPAs (transmetatarsal, Syme, and Chopart) versus BKAs. Logistic regression analysis was used to determine contributions of patient- and hospital-level factors to likelihood of undergoing LPA versus BKA.
Results: The study cohort represented 110,355 admissions nationally: 42,375 LPAs and 67,980 BKAs. The population was predominantly white (56.85%), older than 50 years (82.55%), and male (70.38%). On multivariate analysis, living in an urban area (relative risk ratio [RRR] = 1.48; P < .0001) and having vascular intervention in the same hospital stay (RRR = 2.96; P < .0001) were predictive of LPA. Patients from rural locations but treated in urban centers were more likely to receive BKA. Minorities were more likely to present with severe disease, limiting delivery of LPAs. A high Elixhauser comorbidity score was related to BKA receipt.
Conclusions: This study identifies delivery biases in amputation level for patients without access to large, urban hospitals. Rural patients seeking care in these centers are more likely to receive higher-level amputations. Further examination is required to determine whether earlier referral to multidisciplinary centers is more effective at reducing BKA rates versus satellite centers in rural localities.
This historical perspective highlights some of the pioneers, milestones, teams, and system changes that have had a major impact on management of the diabetic foot during the past 100 years. In 1934, American diabetologist Elliott P. Joslin noted that mortality from diabetic coma had fallen from 60% to 5% after the introduction of insulin, yet deaths from diabetic gangrene of the lower extremity had risen significantly. He believed that diabetic gangrene was preventable. His remedy was a team approach that included foot care, diet, exercise, prompt treatment of foot infections, and specialized surgical care.
The history of the team approach to management of the diabetic foot chronicles the rise of a new health profession—podiatric medicine and surgery—and emergence of the specialty of vascular surgery. The partnership among the diabetologist, vascular surgeon, and podiatric surgeon is a natural one. The complementary skills and knowledge of each can improve limb salvage and functional outcomes. Comprehensive multidisciplinary foot-care programs have been shown to increase quality of care and reduce amputation rates by 36% to 86%. Development of distal revascularization techniques to restore pulsatile blood flow to the foot has also been a major advancement.
Patients with diabetic foot complications are among the most complex and vulnerable of all patient populations. Specialized diabetic foot clinics of the 21st century should be multidisciplinary and equipped to coordinate diagnosis, off-loading, and preventive care; to perform revascularization procedures; to aggressively treat infections; and to manage medical comorbidities. (J Am Podiatr Med Assoc 100(5): 317–334, 2010)
Digestion of collagen with clostridial collagenase (CC) produces peptides that can induce cellular responses consistent with wound healing in vivo. However, nonhealing human wounds are typically in a state of chronic inflammation. We evaluated the effects of CC on markers of inflammation in cell culture and wound fluid from diabetic patients.
Lipopolysaccharide-induced release of tumor necrosis factor-α and interleukin-6 from interferon-γ–activated THP-1 monocytes was measured in the presence or absence of CC or CC collagen digests. In the clinical study, 17 individuals with mildly inflamed diabetic foot ulcers were randomized to receive CC ointment (CCO) or hydrogel. Weekly assessments included wound appearance and measurements. Wound exudate was collected at baseline and at 2 and 4 weeks of treatment. A multiplex assay was used to measure levels of analytes, including those associated with inflammation and with inflammation resolution.
Lower levels of tumor necrosis factor-α and interleukin-6 were found in media of cells cultured with CC or CC digests of collagen type I or III than for untreated lipopolysaccharide controls (P < .05). Clinically, CCO and hydrogel resulted in improvement in wound appearance and a decrease in mean wound area. The CCO, but not the hydrogel, was found to increase the level of analytes associated with resolution of inflammation while decreasing those associated with inflammation. There was a general correlation between resolution of inflammation and healing.
These results support a hypothesis that debridement with CCO is associated with decreased inflammation and greater progress toward healing.
Surgical intervention for chronic deformities and ulcerations has become an important component in the management of patients with diabetes mellitus. Such patients are no longer relegated to wearing cumbersome braces or footwear for deformities that might otherwise be easily corrected. Although surgical intervention in these often high-risk individuals is not without risk, the outcomes are fairly predictable when patients are properly selected and evaluated. In this brief review, we discuss the rationale and indications for diabetic foot surgery, focusing on the surgical decompression of deformities that frequently lead to foot ulcers. (J Am Podiatr Med Assoc 100(5): 369–384, 2010)