Overview of the diabetic foot

Scar free healing of full thickness diabetic wounds: A unique combination of silver nanoparticles as antimicrobial agent, calcium alginate nanoparticles as hemostatic agent, fresh blood as nutrient/growth factor supplier and chitosan as base matrix

Healing of diabetic wounds present a big challenge due to insufficient vascular supply and bacterial infection. We developed chitosan based biodegradable polymeric hydrogel containing silver nanoparticles (AgNPs) as antimicrobial agent and calcium alginate nanoparticles (Ca-AlgNps) as hemostatic agent to address this problem. The prepared Chitosan/Ca-AlgNps/AgNPs hydrogel showed broad spectrum antimicrobial properties against both Gram negative (E. coli, P. aeruginosa) and Gram positive (B. subtilis, S. aureus) bacteria. Taken into account the blood as a vital material containing various circulatory fibrocytes, growth factors, cytokines, platelets and macrophages etc., we incorporated the fresh blood of the same animal to the prepared Chitosan/Ca-Alg Nps/AgNPs hydrogel. In-vivo animal studies of Chitosan/Ca-AlgNps/AgNPs hydrogel and blood mixed Chitosan/Ca-AlgNps/AgNPs hydrogel exhibit 83.5 ± 4.4% and 99.8 ± 2.0% closure of wound respectively, on day 15 as compared to 41.5 ± 3.2% in diabetic control and 60.3 ± 2.2% in commercially available wound healing cream, Silverex Heal. The incorporation of fresh blood to the prepared hydrogel has advantage in terms of supplying growth factors, platelets, circulatory fibrocytes and cytokines which further enhanced the wound healing mechanism in diabetic rats. This work opens a novel idea to formulate hydrogels based dressings for diabetic wound healing.

Index of Plantar Pressure Alters with Prolonged Diabetes Duration

INTRODUCTION

Diabetic foot ulcers develop with deviations in the distribution of plantar pressure. It is difficult to interpret any alteration in plantar pressure under different conditions of type 2 diabetes mellitus (T2DM). The aim of this study was to gain a better insight into the variations in plantar pressure with increased duration of diabetes.

METHODS

Plantar pressure was examined in 1196 participants with or without T2DM. Subjects with normal glucose tolerance (NGT) and impaired glucose tolerance (IGT) were assigned to control groups, and those with T2DM were divided into five groups according to diabetes duration (< 2 years, 2-5 years, 5-10 years, 10-15 years, and > 15 years). The clinical characteristics, plantar peak pressure, and pressure-time integral (PTI) were compared among the seven study groups, and factors associated with peak pressure and the PTI were analyzed.

RESULTS

At the hallux, peak pressure exhibited an upward trend in patients with T2DM within 5 years of diabetes duration, followed by a distinct downward slope with further progression of the disease (trend analysis, p  < 0.05). An uneven distribution of peak pressure was found at other locations, but this unevenness was ultimately lower than that in the two control groups (p  < 0.05). No obvious trend was noted for PTI among patients with different diabetes duration; however, those with diabetes for > 10 years manifested a significantly sharper increase in the PTI at the metatarsus (11.63 Ns/cm², p  < 0.05) and heel (14.12 Ns/cm², p  < 0.05) than at the hallux (8.76 Ns/cm²). A fluctuation in the PTI was also detected at the hallux and midfoot of diabetes patients, which was broadly flat when compared with that of the two control groups. The stepwise multiple regression analysis revealed that the variation in plantar pressure was independently associated with age, body mass index, and vibration perception threshold (VPT) (p  < 0.05).

CONCLUSIONS

There would appear to be an association between longer diabetes duration and decreased peak pressure for the hallux, suggesting that individuals with diabetes for > 10 years will have an increased PTI for the metatarsus and heel. The reduced pressure on the hallux is believed to be transferred to the metatarsus. Age, BMI, and VPT are distinct risk factors of abnormal plantar pressure.

Multidisciplinary approach to soft-tissue reconstruction of the diabetic Charcot foot

BACKGROUND

Diabetics are prone to foot ulceration as a result of local tissue ischemia, immune impairment, and biomechanical derangement in the setting of neuropathy. Healing ulcers in the setting of Charcot neuroarthropathy is challenging, as the skeletal changes usually signify advanced disease.

METHODS

Records were reviewed for all patients with the diagnosis of Charcot neuroarthropathy and ulceration treated over a 7-year period. Demographic data, anatomical wound location, therapeutic interventions, and wound healing rates were recorded.

RESULTS

Three hundred fourteen wounds in 259 patients were examined. One hundred ninety-three wounds with documented follow-up data were analyzed. Fifty wounds (25.9 percent) were on the forefoot, 73 (37.8 percent) were on the midfoot, 28 (14.5 percent) were on the hindfoot, and 42 (21.8 percent) were about the ankle. Wounds were débrided surgically an average of four times. Primary closure was attempted in 29 wounds (15.0 percent). Delayed primary closure was attempted in 35 wounds (18.1 percent). Bioengineered alternative tissues were used in 61 wounds (31.6 percent). Autologous skin grafting was performed on 41 wounds (21.2 percent). Fifteen local flaps (7.8 percent) and five free flaps (2.6 percent) were performed. Forty-eight patients (31.6 percent) required a major amputation. Excluding patients who underwent major amputation, 95 wounds (65.1 percent) were healed at the time of final follow-up.

CONCLUSIONS

The majority of ulcers on Charcot feet required multiple débridements to achieve a clean wound. Multiple therapeutic modalities were used to achieve a 65 percent rate of healing. Despite those efforts, many patients required partial foot or major amputations, with more proximal wounds being at highest risk of the latter.

Manuka honey-impregnated dressings in the treatment of neuropathic diabetic foot ulcers

In this study, we investigate the effect of manuka honey-impregnated dressings (MHID) on the healing of neuropathic diabetic foot ulcers (NDFU). A total of 63 Caucasians, type 2 diabetic patients followed up in the diabetic foot outpatient clinic comprised the study population. Patients were randomised in two groups as follows: group I patients were treated with MHID and group II patients were treated with conventional dressings (CD). The patients were followed up on a weekly basis for 16 weeks. Mean healing time was 31 ± 4 days in group I versus 43 ± 3 days in group II (P < 0·05). In group I patients 78·13% of ulcers became sterile during the first week versus 35·5% in group II patients; the corresponding percentages for weeks 2, 4 and 6 were 15·62% versus 38·7%, 6·25% versus 12·9% and 0% versus 12·9% respectively. The percent of ulcers healed did not differ significantly between groups (97% for MHID and 90% for CD). MHID represent an effective treatment for NDFU leading to a significant reduction in the time of healing and rapid disinfection of ulcers.

Investigating the role of backward walking therapy in alleviating plantar pressure of patients with diabetic peripheral neuropathy

OBJECTIVE

To investigate the effect of combination therapy of backward walking training and alpha-lipoic acid (ALA) treatment on the distribution of plantar pressure in patients with diabetic peripheral neuropathy (DPN).

DESIGN

This study is a double-blinded, randomized controlled trial. The test group was treated with combination therapy of backward walking exercise and ALA (ALA for 2wk, backward walking exercise for 12wk), and the control group only received ALA treatment.

SETTING

Clinical and laboratory setting.

PARTICIPANTS

Patients with DPN (N=60) were divided into the test group (n=30) or control group (n=30).

INTERVENTIONS

Backward walking exercise with ALA treatment for the test group; lipoic acid treatment for the control group.

MAIN OUTCOME MEASURE

Plantar pressure before and after treatment was tested and analyzed with the flatbed plantar pressure measurement system.

RESULTS

After treatment, peak plantar pressure in the forefoot dropped for both the test and control groups; peak plantar pressure for the test group dropped significantly. Peak plantar pressure in the medial foot slightly increased for the test group, suggesting a more even distribution of plantar pressure in the test group after treatment.

CONCLUSIONS

The combination therapy of ALA and backward walking proved to be more effective than ALA monotherapy. Backward walking also proved to have an ameliorating effect on balance ability and muscle strength of patients with DPN.

A solution to ankle-brachial index limitations in peripheral transluminal angioplasty

PURPOSE

We evaluated the limitations of the ankle-brachial index (ABI) in the revascularisation of diabetic patients with critical limb ischaemia (CLI) who were undergoing peripheral transluminal angioplasty (PTA) compared with the degree of arterial stenosis and with transcutaneous oxygen tension (TcpO2).

MATERIALS AND METHODS

This prospective study assessed 250 consecutive diabetic patients in whom we evaluated results of posterior tibial and dorsalis pedis Doppler, ABI, TcpO2, and duplex scans. In total, 104 patients were considered suitable candidates for PTA.

RESULTS

In 42% of the patients studied, ABI could either not be used (9.34% due to no signal; 14.02% because the artery could not be compressed) or was incorrect (18.7% before PTA; 15.9% after PTA). In contrast, TcpO2 was determined in all cases. After PTA, vessel stenosis decreased from 58.33±20.07% to 21.87±13.57% (p<0.001), whereas ABI increased from 0.79±0.57 to 0.95±0.47 (p<0.001) and TcpO2 from 27.37±10.40 mmHg to 38.23±10.25 mmHg (p<0.001). A statistical analysis revealed scant correlation between techniques (TcpO2 and ABI) (r=0.14).

CONCLUSIONS

ABI shows significant limitations for the diagnosing and treating CLI patients compared with TcpO2.

C-reactive protein as an outcome predictor for percutaneous transluminal angioplasty in diabetic patients with peripheral arterial disease and infected foot ulcers

AIM

Although percutaneous transluminal angioplasty (PTA) is an effective therapeutic procedure for critical limb ischemia, several clinical factors can influence the outcome of PTA for peripheral arterial disease (PAD). The aim of this study is to identify the outcome predictors of PTA in infected diabetic foot patients with PAD.

METHODS

Eighty-five diabetic patients with a total of 90 infected limbs treated by PTA participated in this study. Patients were initially admitted for infected foot ulcers and were later diagnosed with PAD. Even though all patients underwent successful PTA within 15 days of admission, limb salvage was successful in 66 cases while 24 underwent subsequent amputation. The clinical characteristics and laboratory variables of both groups before PTA were compared and analyzed.

RESULTS

Significantly higher level of C-reactive protein (CRP) was observed in the major amputation group before PTA. The cutoff value via receiver operating characteristic curve was 50mg/L (81.8% specificity, 70.7% sensitivity). Multivariate logistic regression analysis revealed that CRP levels may serve as valuable marker in determining a successful outcome.

CONCLUSION

Reduced CRP levels (<50mg/L), which indicates a low infection severity, may serve as a major predictor of successful PTA outcome in diabetic patients with infected foot ulcers.

Surgical management of diabetic foot infections and osteomyelitis

Foot ulceration and subsequent infection are a major complication of diabetes mellitus. Without proper diagnosis and treatment, these infections often lead to amputation. A multidisciplinary team approach is essential to maximize outcomes in the attempt to limit amputation and decrease patient morbidity. Mild to moderate diabetic foot infections often respond favorably to local wound care, offloading, and antibiotic therapy. When conservative measures fail or when faced with limb- or life-threatening infection, surgical intervention, whether it be incision and drainage or possible amputation, is warranted. The authors review underlying pathophysiology of diabetic foot infections and an evidenced-based approach to surgical management, with additional emphasis on treatment of osteomyelitis.

Syme amputation for limb salvage: early experience with 26 cases

The Syme amputation is often overlooked as an alternative to below-knee amputation or above-knee amputation in cases of limb-threatening foot infections and gangrene. Even though the advantages of the Syme amputation over major amputation are well cited in the literature, many surgeons do not view this amputation as a viable option for limb salvage. We herein present our initial experience with this operation in a series of patients at imminent risk for major lower extremity amputation. This study included our initial 26 patients at high risk (92% had diabetes) with infection and/or significant peripheral arterial disease who underwent ankle disarticulation for limb salvage. Medical records were abstracted for pertinent demographic and clinical data. Variables of interest included diabetes status and duration, presence of peripheral arterial disease, infection, osteomyelitis, and gangrene. Our primary outcome variable was a healed amputation, whereas secondary outcomes included time to healing, subsequent major amputations, and complications. Despite prior recommendation for below-knee amputation or above-knee amputation in each of these patients, 50% remained healed at an average of 49.3 weeks of follow-up. Although 17 patients (65.4%) ambulated in a Syme prosthesis after healing of the original Syme operation, several patients went on to major amputation for progressive sepsis or recurrent ulcers, and 1 patient subsequently died. Because of the relatively small number of study subjects, we could find no significant predictors of success or failure of this procedure. However, all 10 patients eventually succumbing to major amputation and all 3 patients who died during follow-up had diabetes mellitus. At the end of follow-up, 46.2% (12/26) patients were functioning well in a Syme prosthesis. In this high-risk cohort of patients in whom major amputation had been recommended, we achieved a healing rate of 50% at an approximate 1-year follow-up. With the majority of patients having diabetes and peripheral vascular disease, we could not find any clear predictive factors for failure or successful outcome in this small population. Nonetheless, the Syme amputation deserves further study and consideration as a viable limb salvage option in patients threatened with major lower extremity amputation.

Diabetic foot disorders. A clinical practice guideline (2006 revision)

The prevalence of diabetes mellitus is growing at epidemic proportions in the United States and worldwide. Most alarming is the steady increase in type 2 diabetes, especially among young and obese people. An estimated 7% of the US population has diabetes, and because of the increased longevity of this population, diabetes-associated complications are expected to rise in prevalence. Foot ulcerations, infections, Charcot neuroarthropathy, and peripheral arterial disease frequently result in gangrene and lower limb amputation. Consequently, foot disorders are leading causes of hospitalization for persons with diabetes and account for billion-dollar expenditures annually in the US. Although not all foot complications can be prevented, dramatic reductions in frequency have been achieved by taking a multidisciplinary approach to patient management. Using this concept, the authors present a clinical practice guideline for diabetic foot disorders based on currently available evidence, committee consensus, and current clinical practice. The pathophysiology and treatment of diabetic foot ulcers, infections, and the diabetic Charcot foot are reviewed. While these guidelines cannot and should not dictate the care of all affected patients, they provide evidence-based guidance for general patterns of practice. If these concepts are embraced and incorporated into patient management protocols, a major reduction in diabetic limb amputations is certainly an attainable goal.

Osteomyelitis of the foot and toe in adults is a surgical disease: conservative management worsens lower extremity salvage

OBJECTIVE

To characterize the national epidemiology of adult osteomyelitis (OM) and, using a single institutions' experience, test the hypothesis that early surgical therapy as compared with antibiotics alone results in an improved chance of wound healing and limb salvage.

BACKGROUND

Foot and digit OM is a very common problem for which management is variable and for which few guidelines exist.

METHODS

The Nationwide Inpatient Sample (NIS) and a single institution review from 1993 to 2000 form the basis of this study, using ICD-9CM codes for lower extremity foot and digit OM. Demographics, risk factors, and treatments were analyzed against the outcomes of a healed wound, limb salvage, and death.

RESULTS

The NIS included 51,875 patients (incidence = 9/10,000 patients per year) with a mean age of 60 years, and 59% were men. The median length of stay decreased from 9 to 6 days (P < 0.001), but the average admission charge of 19,000 dollars did not significantly decrease over 7 years. Of these patients, 23% underwent a digit amputation and 8.5% suffered proximal limb loss. Single-institution analysis of 237 consecutive patients with OM confirmed a similar mean age (58 years), gender (67% men), and most presented with a foot or digit ulcer (56%). Wound healing was achieved in 56% and overall limb salvage was 80%. Decreased wound healing was associated with peripheral vascular occlusive disease (odds ratio, 0.4; 95% confidence interval, 0.2-0.8, P = 0.006) and preadmission antibiotic use (odds ratio, 0.2; 95% confidence interval, 0.05-1.1, P=0.07), while surgical debridement (odds ratio, 2.2; 95% confidence interval, 1.2-4.2, P = 0.02) was associated with increased healing. Limb salvage was improved with an arterial bypass (odds ratio, 3.9; 95% confidence interval, 1.1-14, P = 0.04), while preadmission solid organ transplant (odds ratio, 0.37; 95% confidence interval, 0.14-0.96, P = 0.04), peripheral vascular occlusive disease (odds ratio, 0.25; 95% confidence interval, 0.12-0.5, P = 0.001), and preadmission antibiotic use (odds ratio, 0.34; 95% confidence interval, 0.15-0.77, P = 0.009) were associated with greater limb loss.

CONCLUSION

Digit OM is an expensive and morbid disease. Aggressive surgical debridement/digit amputation and selected use of arterial bypass should improve wound healing and limb salvage, respectively. In contrast, antibiotic therapy alone is associated with decreased wound healing and limb salvage.