Clinical presentation and management of diabetic neuropathy and foot ulceration

Ultrasonographic Evaluation of Thickness and Stiffness of Achilles Tendon and Plantar Fascia in Type 2 Diabetics Patients: A Cross-sectional Observation Study

Background

Diabetes mellitus (DM) can contribute to the development of foot ulcers, a known complication of DM with a high financial and social burden. Achilles tendon (AT) and plantar fascia (PF) are well known to play an important role in foot biomechanics. The present study focuses on the alteration in thickness and stiffness of the AT and PF in Type 2 DM patients compared with the normal controls.

Methods

A cross-sectional observational study was conducted with 55 DM patients and 55 healthy volunteers as controls. The thickness of the AT and PF were measured using B-mode ultrasound and stiffness was measured using shear wave elastography. Both the thickness and stiffness in the patient group and controls were compared. The values were also compared with the clinical and demographic profiles of the patients.

Results

DM patients had considerably thicker AT and PF than controls (P < 0.05); mean values of AT thickness for DM patients and controls were 5.66 ± 0.54 mm and 4.61 ± 0.39 mm, respectively, and for PF were 2.53 ± 0.51 mm and 1.97 ± 0.19 mm, respectively. Furthermore, the stiffness of AT and PF was significantly (P < 0.05) lower in DM patients compared to controls, suggestive of softening of AT and PF in Type 2 DM patients. Mean values of shear wave velocity for DM patients and controls in AT were 5.53 ± 0.54 m/s and 7.25 ± 0.61 m/s, respectively, and for PF, 4.53 ± 0.89 m/s and 6.28 ± 0.88 m/s, respectively.

Conclusion

We conclude that there is softening and thickening of the AT and PF in Type 2 DM patients, which can impair foot biomechanics.

Exploration of Lipid-Based Nanocarriers as Drug Delivery Systems in Diabetic Foot Ulcer

Diabetes mellitus is a chronic manifestation characterized by high levels of glucose in the blood resulting in several complications including diabetic wounds and ulcers, which predominantly require a longer duration of treatment and adversely affect the quality of life of the patients. Nanotechnology-based therapeutics (both intrinsic and extrinsic types) have emerged as a promising treatment in diabetic foot ulcer/chronic wounds owing to their unique characteristics and specific functional properties. In this review, we have focused on the significance of the use of lipids in the healing of diabetic ulcers, their interaction with the injured skin, and recent trends in lipid-based nanocarriers for the healing of diabetic wounds. Lipid nanocarriers are also being investigated for gene therapy in diabetic wound healing to encapsulate nucleic acids such as siRNA and miRNA, which could silence the expression of inflammatory cytokines overexpressed in chronic wounds. Additionally, these are also being explored for encapsulating proteins, peptides, growth factors, and other biological genetic material as therapeutic agents. Lipid-based nanocarriers encompassing a wide variety of carriers such as liposomes, niosomes, ethosomes, solid lipid nanoparticles, and lipidoid nanoparticles that are explored for the treatment of foot ulcers supplemented with relevant research studies have been discussed in the present review. Lipid-based nanodrug delivery systems have demonstrated promising wound healing potential, particularly in diabetic conditions due to the enhanced efficacy of the entrapped active molecules.

[Diabetic foot syndrome-Part 1 : Definition, pathophysiology, diagnostics and classification]

There are ca. 8 million persons with diabetes mellitus living in Germany. A late sequelae of diabetes is the diabetic foot syndrome (DFS), the prevalence of which is greatly increasing. It comprises all alterations of the foot as a result of diabetic polyneuropathy as well as microvascular and macrovascular (peripheral arterial occlusive disease, PAOD) alterations. Many of the ca. 250,000 newly diagnosed diabetic foot ulcers per year become chronic wounds. Despite intensive efforts for prevention, early diagnosis and adequate wound care, ca. 13,000 persons with diabetes undergo major limb amputation in Germany every year. With consistent treatment in interdisciplinary centers and by exhausting all possible methods of wound treatment, pressure relief as well as arterial revascularization, the major amputation rate in patients with diabetic foot problems can be reduced by 80%. With a suitable strategy of prevention, the recurrence rate of foot ulcers would be reduced.

Clinical Outcomes of Wide Postsurgical Lesions in the Infected Diabetic Foot Managed With 2 Different Local Treatment Regimes Compared Using a Quasi-Experimental Study Design: A Preliminary Communication

The safety and efficacy of a novel superoxidized solution (Dermacyn™ Wound Care [DWC], Oculus Innovative Sciences, Petaluma, Calif) was evaluated for the treatment of wide postsurgical infected ulcers of the diabetic foot. A group (group A,n = 18) of patients with diabetes mellitus who had postsurgical lesions>5 cm2 without ischemia or infection were recruited consecutively and treated with DWC-saturated dressings. These dressings were renewed once daily and were compared with a group of patients that had been previously treated with diluted povidone iodine (group B,n = 15) using a quasi-experimental study design. Both sets of patients also received standard systemic antibiotic therapy, as per the practice in this center, and local surgical debridement. Patients had weekly assessments until wounds had re-epithelialized completely. Patients in group A had statistically significant shorter healing time and duration of antibiotic therapy and a higher healing rate at 6 months compared with those in group B (p < .01). Recurrence of infection, requirement for debridement procedures, and requirement for minor amputations were significantly less frequent during follow-up in group A patients (p < .05) when compared with those in group B. These preliminary data suggest that DWC used as a wound dressing together with other local and systemic therapies may have a role in reducing healing time as well as complications in patients with diabetes who have postsurgical lesions of the diabetic foot. These data propose the need for a robust controlled study of DWC-saturated dressings to explore its full potential.

Outcomes of three years of teamwork on critical limb ischemia in patients with diabetes and foot lesions

To evaluate the outcomes of a multidisciplinary team working on diabetic foot (DF) patients with critical limb ischemia (CLI) in a specialized center, the authors retrospectively traced all the patients admitted in their department in 3 consecutive years with a diagnosis of CLI. From January 2006 to December 2008, 245 consecutive DF patients with CLI according the TransAtlantic interSociety Consensus II criteria were included in the study. Treatment strategy was decided by a team of diabetologists, inteventional radiologists, and vascular surgeons. Technical and clinical success, mortality, and ulcer recurrence were evaluated at 6 months and at a mean follow-up of 19.5 ± 13.4 months. Percutaneous transluminal angioplasty (PTA) was performed in 189 (77%) patients, whereas medical treatment, open surgical revascularization (OSR), and primary amputation were performed in 44 (18.3%), 11 (4.3%), and 1 (0.5%) patients, respectively. Revascularization was successful in 227/233 (97.4%) patients. At follow-up, the overall clinical success rate was 60.4%; it was significantly (P = .001) higher after revascularization (75.9%) compared with medical treatment (48.3%). During follow-up, surgical interventions in the foot were 1.5 ± 0.4 in those treated with PTA, 1.6 ± 0.5 in those treated with OSR, and 0.3 ± 0.8 in those receiving medical therapy (P < .05 compared with the others). Ulcer recurrence occurred in 29 (11.8%) patients: 4 (1.6%) in PTA, 2 (0.8%) in OSR, and 23 (9.4%) in the medical therapy group (P < .05). Major amputation rate was 9.3%, being significantly (P = .04) lower after revascularization (5.2%) compared with medical therapy alone (13.8%). Cumulative mortality rate was 10.6%. In conclusion, this study confirms the positive role of a PTA-first approach for revascularizing the complex cases of DF with CLI in a teamwork management strategy.

[Diagnostics and therapy of the diabetic foot syndrome from a vascular surgery perspective]

There are more than 6 million diabetic patients in Germany. Due to neuropathic and angiopathic long term damage the number of patients with diabetic foot syndrome has been increasing dramatically over the past years. Despite all efforts for prevention, early diagnosis and adequate therapy, more than 20,000 diabetics undergo major limb amputation in Germany every year. A major portion of these amputations could be avoided if an improvement of the arterial perfusion would be timely considered. By consequent therapy in interdisciplinary centres, and by applying all methods of arterial revascularization, the amputation rate in patients with diabetic foot problems could be reduced by 80%. This article describes the diagnostics and therapy of the diabetic foot syndrome from a vascular surgical point of view. The importance of endovascular, vascular surgical as well as combined (hybrid) procedures of revascularization is emphasized.

A Randomized Controlled Trial to Examine the Efficacy and Safety of a New Super-Oxidized Solution for the Management of Wide Postsurgical Lesions of the Diabetic Foot

This randomized trial was done to test the effectiveness and safety of using a novel antiseptic solution (Dermacyn® Wound Care [DWC], Oculus Innovative Sciences, Petaluma, CA) in the management of the postoperative lesions on the infected diabetic foot. 40 patients with postsurgical lesions wider than 5 cm2 left open to heal by secondary intention were randomized into 2 groups. Group A was locally treated with DWC, whereas group B received povidone iodine as local medication, both in adjunct to systemic antibiotic therapy and surgical debridement if needed. Ischemia, renal failure, bilateral lesions, or immunodepression were considered as exclusion criteria. Patients were followed up weekly for 6 months. The primary endpoint was healing rate at 6 months, while secondary endpoints were healing time, time to achieve negative cultures, duration of antibiotic therapy, number of reinterventions, and adverse events. Healing rates at 6 months were significantly shorter in group A (90%) than in group B (55%; P < .01). The time taken for cultures to become negative and duration of antibiotic therapy were also significantly (P < .05) shorter in group A than in group B, whereas the number of reinterventions was significantly higher in group B (P < .05). No difference was noted in the adverse events except that for reinfections, which were more frequent in group B than in group A (P < .01). DWC is as safe as and more effective than standard local antiseptics in the management of wide postsurgical lesions in the infected diabetic foot.

[The diabetic foot]

In the last 20 years the prevalence of diabetes in Germany has increased by approximately 50%. Associated with this is a distinct rise of diabetes-induced comorbidities and long-term consequences. One of the most frequent consequences is the diabetic foot or the diabetic foot syndrome. This is an ulceration of neuropathic and angiopathic origin, which often reaches a chronic stadium due to a poor healing tendency. Despite the disease management program for diabetes in Germany which mainly concentrates on the prophylaxis and multidisciplinary treatment of chronic diseases, there are approximately 250,000 patients with lesions of the foot caused by diabetes of which approximately 50% have to be amputated within 4 years. To achieve a reduction of the amputation rate identification of the main reasons is necessary. In addition a professional therapy of the vascular disorders and a stage-adjusted wound therapy have to take place in an interdisciplinary collaboration in a centre for wound care. Last but not least this aim can only be achieved by a preventive education of diabetics.

Effectiveness and safety of using Podikon digital silicone padding in the primary prevention of neuropathic lesions in the forefoot of diabetic patients

BACKGROUND

In diabetic patients with complications from peripheral neuropathy, the hyperpressure areas can rapidly lead to ulcerative lesions in the absence of protective sensation. Partial digital silicone orthoses could provide an innovative and functional therapeutic solution in the management of preulcerative areas of the forefoot in neuropathic diabetic patients. We clinically tested this hypothesis.

METHODS

Digital off-loading silicone padding was prepared for 89 neuropathic patients with deformities and localized hyperkeratosis in the forefoot. After 3 months and in basal conditions, the number of areas of hyperkeratosis was evaluated together with the hardness of the skin, the number of active lesions, and any adverse events associated with use of the orthosis. The patients were compared to a control group of 78 randomized patients undergoing standard therapy. In a subgroup of 10 patients, a static and dynamic biomechanical evaluation was also conducted with a computerized podobarometric platform.

RESULTS

Both the number of lesions and the prevalence of hyperkeratosis and skin hardness were significantly lower (P < .01) in the group treated with the silicone orthoses than in the control group. No adverse events were reported during the 3 months of observation. The podobarometric analysis highlighted a significant (P < .001) reduction of peak pressure in the areas undergoing orthotic correction.

CONCLUSIONS

Silicone padding is effective and safe in the prevention of lesions in neuropathic patients at high risk of ulceration and significantly reduces the incidence of new lesions in the 3-month follow-up period compared to standard treatment.

[The vascular surgeon's role in interdisciplinary treatment of diabetic foot syndrome]

There are more than 6 million diabetes patients in Germany. Due to long-term neuropathic and angiopathic sequelae, the number of patients with "diabetic foot syndrome" has increased dramatically in recent years. Diabetic foot ulcers have become one of the most common pathologies in interdisciplinary wound care centers. Because of its complex pathogenesis, diabetic foot syndrome needs a multidisciplinary therapeutic approach. More than 150,000 diabetics per year develop foot ulcers that often heal slowly and progress into chronic wounds. Despite all efforts at prevention, early diagnosis, and adequate therapy, more than 20,000 diabetics suffer major limb amputation in Germany every year. Applying stringent standards of care in interdisciplinary wound care centers, the amputation rate in patients with diabetic foot syndrome can be reduced to less than 50%. This article describes the complexity of diabetic foot syndrome with respect to pathogenesis, diagnostics, and therapy from a vascular surgeon's point of view. The importance of an interdisciplinary approach is emphasized.

Muscle performance and ankle joint mobility in long-term patients with diabetes

Background

Long-term patients with diabetes and peripheral neuropathy show altered foot biomechanics and abnormal foot loading. This study aimed at assessing muscle performance and ankle mobility in such patients under controlled conditions.

Methods

Forty six long-term diabetes patients with (DN) and without (D) peripheral neuropathy, and 21 controls (C) were examined. Lower leg muscle performance and ankle mobility were assessed by means of a dedicated equipment, with the patient seated and the examined limb unloaded. 3D active ranges of motion and moments of force were recorded, the latter during maximal isometric contractions, with the foot blocked in different positions.

Results

All patients showed reduced ankle mobility. In the sagittal and transversal planes reduction vs C was 11% and 20% for D, 20% and 21% for DN, respectively.

Dorsal-flexing moments were significantly reduced in all patients and foot positions, the highest reduction being 28% for D and 37% for DN. Reductions of plantar-flexing moments were in the range 12–15% for D (only with the foot blocked in neutral and in dorsal-flexed position), and in the range 10–24% for DN. In all patients, reductions in the frontal and transversal planes ranged 14–41%.

Conclusion

The investigation revealed ankle functional impairments in patients with diabetes, with or without neuropathy, thus suggesting that other mechanisms besides neuropathy might contribute to alter foot-ankle biomechanics. Such impairments may then play a role in the development of abnormal gait and in the onset of plantar ulcers.

Best practice in the assessment and management of diabetic foot ulcers

Diabetes is an increasingly serious health issue in the rehabilitation population. Foot ulcers develop in approximately 15% of people with diabetes and are a preceding factor in approximately 85% of lower limb amputations. Nurses have significant opportunity to positively influence client outcomes and quality of life by promoting maintenance of healthy feet, identifying emerging problems, and supporting evidence-based self-care and interdisciplinary intervention. Best practice guidelines (BPG), such as those developed by the Registered Nurses Association of Ontario, provide a framework to enhance nursing practice and promote excellence in client care. This article highlights key evidence from the BPG, "Assessment and Management of Foot Ulcers for People with Diabetes," and other relevant diabetes literature. This information better equips rehabilitation nurses to promote ulcer prevention strategies; identifies key factors in ulcer risk; and utilizes current, best evidence for ulcer assessment, management, and evaluation.

Peak pressure curve: an effective parameter for early detection of foot functional impairments in diabetic patients

A clinical investigation was conducted on 61 diabetic patients and 22 healthy volunteers. Joint mobility, muscular function of the foot-ankle complex and plantar pressure measurements were characterised. A clustering algorithm was applied to obtain patient classification based on the shape and amplitude of the time curve of the instantaneous maximum pressure the foot experienced during gait. Results indicate that a screening test based on the peak pressure curve might be an effective way to detect diabetic patients at risk of foot ulceration.

F-wave and H-reflex alterations in recently diagnosed diabetic patients

OBJECTIVE

To explore the frequency of F-wave and H-reflex alterations in recently diagnosed type 2 diabetes mellitus patients and to determine if the alterations are dependent on the levels of glycemia.

METHODS

A cross-sectional study was carried out on 50 asymptomatic patients, with a mean age of 45.4 +/- 9.8 years and a disease evolution of less than 10 years. Patients were classified as either normoglycemic (7 mmol/L; n = 20) or hyperglycemic (7 mmol/L; n = 30). H-reflex (HR), F-wave (FW), and nerve-conduction measurements (NCM) between the diabetic and non-diabetic (control) groups were compared.

RESULTS

The H-reflex was absent in 22% of the patients, while the M-component of this reflex was altered in 58% of patients. The F-wave was altered in 12% of the patients. The motor nerve compound action potential showed a diminution in amplitude (26% of patients, n = 13), area (32%, n = 16), and conduction velocity (20%, n = 10). No positive correlation between glycemia levels and the above alterations was found.

CONCLUSIONS

This study demonstrated that asymptomatic diabetic patients showed a high incidence of subclinical neurophysiological abnormalities.

Does the thickening of Achilles tendon and plantar fascia contribute to the alteration of diabetic foot loading?

BACKGROUND

The diabetic foot often undergoes abnormal plantar pressures, changing in walking strategy, ulcerative processes. The present study focuses on the effects that diabetes-induced alterations of Achilles tendon, plantar fascia and first metatarso-phalangeal joint-both anatomical and functional-may have on foot loading.

METHODS

Sixty-one diabetic patients, with or without neuropathy, and 21 healthy volunteers were recruited. Thickness of Achilles tendon and plantar fascia was measured by ultrasound. Flexion-extension of the first metatarso-phalangeal joint was measured passively. Main biomechanic parameters of foot-floor interaction during gait were acquired and related to the above measurements.

FINDINGS

Plantar fascia and Achilles tendon were significantly (P<0.05) thicker in diabetics than in controls; mean values (SD) for controls, diabetics without and with neuropathy were 2.0 mm (0.5), 2.9 mm (1.2) and 3.0 mm (0.8) for plantar fascia, respectively, and 4.0 mm (0.5), 4.6 mm (1.0) and 4.9 mm (1.7) for Achilles tendon, respectively. Flexion-extension of the first metatarso-phalangeal joint was significantly (P<0.05) smaller in diabetics than in controls; mean values (SD) for controls, diabetics without and with neuropathy were 100.0 degrees (10.0), 54.0 degrees (29.4) and 54.9 degrees (17.2), respectively. The increase in the vertical force under the metatarsals was strongly related (R=0.83, explained variance=70.1%) to the changes in the three above parameters.

INTERPRETATION

Thickening of plantar fascia and Achilles tendon in diabetics, more evident in the presence of neuropathy, concurs to develop a rigid foot, which poorly absorbs shock during landing (performs the physiological impact force absorption during landing). More generally, an overall alteration of the foot-ankle complex motion likely occurs throughout the whole gait cycle, which partly explains the abnormal loading under the forefoot.

Semiquantitative analysis of the histopathological features of the neuropathic foot ulcer: effects of pressure relief

OBJECTIVE

This study was designed to evaluate the histopathology of neuropathic ulcers and whether pressure relief could change such histological patterns.

RESEARCH DESIGN AND METHODS

We compared neuropathic plantar ulcers tissue excised from 10 diabetic patients (group A) with those taken from 10 patients with comparable lesions and glycemic control after 20 days in a total contact cast (group B). Tissue specimens were blindly examined by two independent pathologists for hyperkeratosis, fibrosis, cutaneous annexes, capillaries, inflammation, cellular debris, and granulating tissue. For each parameter, quantification was obtained according to an arbitrary score: 0, absent; 1, present in <33%; 2, present in 34-66%; and 3, present in >67% of the lesion.

RESULTS

Patients in group B showed a marked reduction in ulcer size after 20 days of casting (P < 0.01). The histopathological features of the two groups markedly differed. Group A patients showed a predominance of inflammatory elements as well as matrix alterations, vessel disruptions, inflammation, and debris. Group B ulcers showed a shift toward a reparative pattern with prevalence of neoformed capillaries and fibroblasts. Semiquantitative analysis confirmed the prevalence of hyperkeratosis, fibrosis, inflammation, and cellular debris in group A patients (P < 0.05), whereas cutaneous annexes, capillaries, and granulating tissue were more prevalent in group B lesions (P < 0.01).

CONCLUSIONS

These results indicate that pressure relief with a total contact cast is associated with changes in the histology of neuropathic foot ulcers, indicating reduction of inflammatory and reactive components and acceleration of reparative processes.

Clinical potential of insulin therapy in critically ill patients

Stress of critical illness is often accompanied by hyperglycaemia, whether or not the patient has a history of diabetes mellitus. This has been considered to be part of the adaptive metabolic response to stress. The level of hyperglycaemia in patients with acute myocardial infarction (MI) or stroke upon admission to the hospital has been related to the risk of adverse outcome. However, until recently, there was no evidence of a causal relationship and thus stress-induced hyperglycaemia was only treated with exogenous insulin when it exceeded 12 mmol/L (220 mg/dL). In patients with known diabetes, even higher levels were often tolerated. Recently, new data became available in support of another approach. In this review, we focus on the new evidence and the clinical aspects of managing hyperglycaemia with insulin in critically ill patients, drawing a parallel with diabetes management. Particularly, the 'Diabetes and Insulin-Glucose infusion in Acute Myocardial Infarction (DIGAMI) study' and the 'insulin in intensive care study' have provided novel insights. The DIGAMI study showed that in patients with diabetes, controlling blood glucose levels below 12 mmol/L for 3 months after acute MI improves long-term outcome. In the recent study of predominantly surgical intensive care patients, the majority of whom did not previously have diabetes, it was shown that an even tighter control of blood glucose with exogenous insulin, aiming for normoglycaemia, dramatically improved outcome. Indeed, in this large prospective, randomised, controlled study, 1548 intensive care patients had been randomly allocated to either the conventional approach, with insulin infusion started only when blood glucose levels exceeded 12 mmol/L, or intensive insulin therapy, with insulin infused to maintain blood glucose at a level of 4.5-6.1 mmol/L (80-110 mg/dL). Intensive insulin therapy reduced intensive care mortality by more than 40% and also decreased a number of morbidity factors including acute renal failure, polyneuropathy, ventilator-dependency and septicaemia. Future studies will be needed to further unravel the mechanisms that explain the beneficial effects of this simple and cost-saving intervention. Although available evidence supports implementation of intensive insulin therapy in surgical intensive care, the benefit for other patient populations, such as patients on medical intensive care units or hospitalised patients who do not require intensive care but who do present with stress-induced hyperglycaemia, remains to be investigated.

How should peripheral neuropathy be assessed in people with diabetes in primary care? A population-based comparison of four measures

AIMS

To test the accuracy of four measures of peripheral diabetic neuropathy in a primary care population.

METHODS

Type 2 diabetic (n = 544) and 544 non-diabetic participants aged 45-76 years were randomly selected from general practice registers. Neuropathy was assessed using vibration threshold (VT) and scores for light touch, thermal sense and modified Michigan Neuropathy Screening Instrument questionnaire. These measures were assessed for variation with diabetes status, age, diabetes duration, HbA1c, and presence of retinopathy and nephropathy. Light touch, thermal sense and questionnaire scores were assessed against VT using ROC curve analysis.

RESULTS

Only VT and light touch were different between diabetic and non-diabetic groups (P = 0.02 and < 0.0001, respectively). All measures were significantly associated with diabetes duration and retinopathy, and all except questionnaire score (P = 0.14) with age. None was associated with nephropathy and only questionnaire score was associated with HbA1c (P = 0.033). VT varied as expected across scores of light touch (chi2 = 41.65, P = 0.0001), thermal sense (chi2 = 15.86, P = 0.015) and questionnaire (chi2 = 21.22, P = 0.047). Area under the curve values for light touch, thermal and questionnaire scores were 0.72 (95% confidence interval (CI) 0.63, 0.82), 0.63 (95% CI 0.52, 0.73) and 0.64 (95% CI 0.53, 0.74), respectively.

CONCLUSIONS

All measures had associations with risk factors for neuropathy, but light touch score (monofilament) had the strongest association with vibration threshold (the chosen gold standard) and thus appeared the most appropriate tool for use in primary care, because of its validity and simplicity of use.

Sodium carboxyl-methyl-cellulose dressings in the management of deep ulcerations of diabetic foot

AIMS

To test the safety and effectiveness of carboxyl-methyl-cellulose dressing (Aquacel; ConvaTec, UK) in the management of deep diabetic foot ulcers, a group of consecutive out-patients attending the foot clinic of the Department of Metabolic Diseases was studied.

METHODS

Patients were selected according to the following inclusion criteria: a foot ulcer deeper than 1 cm for > 3 weeks, good peripheral blood supply (palpable peripheral pulses or ABPI > 0.9). Exclusion criteria were as follows: active infection, as evident from clinical signs (purulent discharge, redness, swelling, tenderness) and confirmed by culture exams, plasma creatinine > 2 mg/dl, recent episodes of ketoacidosis, malignancies, and any therapy or pathology which might interfere with the healing process. Twenty patients were enrolled in the study and having obtained their informed consent, their lesions were surgically debrided with the complete elimination of all necrotic tissue and debris up to the bleeding healthy tissue; then ulcers were staged and measured, and patients were randomly assigned to two different treatment groups. Patients in group A were dressed with saline-moistened gauze, while patients in group B were dressed with Aquacel according to the manufacturer's instructions. All patients in both groups received special post-operative shoes (Podiabetes; Zeno Buratto, Treviso, Italy) and crutches until complete re-epithelialization. Ulcers were all left to heal by secondary intent. After 8 weeks patients were blindly evaluated for: the rate of reduction of lesional volume (RLV), rate of granulation tissue (GT), number of infective complications (IC). Intralesional (ILTC) and perilesional (PLTC) temperatures were also recorded with a thermocouple surface digital thermometer, and the difference between the two values (Delta TC) was calculated. Healing time (HT, days), was then compared between the two groups. Data were compared by analysis of variance (ANOVA), linear regression, Kaplan-Meier survival analysis and Fisher's exact test.

RESULTS

HT was significantly shorter in Group B than in Group A (P < 0.001). RLV was significantly (P < 0.01) higher in Group B patients compared with Group A, as well as GT (P < 0.05). IC were in 1/10 Group B and in 3/10 Group A (P = 0.582). In addition, both ILTC and Delta TC were higher in Group B compared with Group A ones (P < 0.01).

CONCLUSIONS

Carboxyl-methyl-cellulose dressings were shown to be safe, effective and well tolerated in the management of non-ischaemic, non-infected deep diabetic foot ulcers.

Methods for assessing diabetic polyneuropathy: validity and reproducibility of the measurement of sensory symptom severity and nerve function tests

The usefulness of sensory symptoms in the assessment of diabetic polyneuropathy is unclear. In the present study, we studied the hypothesis that pain is associated with small nerve fibre function, and that sensory alteration is associated with large nerve fibre function. In addition, we assessed the reproducibility and the ability to detect changes in clinical status over time of the nerve function tests currently used in clinical trials. Patients (78) with stable diabetic polyneuropathy were examined on three separate occasions with a test-retest interval of 17 and 52 weeks. Small nerve fibre function was measured using temperature discrimination thresholds for warmth (TDTwarmth) and cold (TDTcold). Large nerve fibre function was measured by testing sensory and motor nerve conduction velocities (SNCV and MNCV) and vibration perception thresholds (VPT). Neuropathic pain was only significantly associated with TDTcold, and with the MNCV of the tibial nerve. Sensory alteration was associated with almost all nerve function tests except the SNCV and MNCV of the ulnar nerve. The measurements of symptom severity and the nerve function tests all proved to be sufficiently reproducible. The standardized smallest detectable difference on group level (SDD) of the measurement of sensory alteration and neuropathic pain were almost the same (9% and 12%, respectively). Among the nerve function tests, the SNCV and MNCV had the smallest SDD (3-4%), and were, therefore, potentially the most responsive instruments. The SDD of the TDT was greater than the VPT (9-14% vs 21-28%, respectively). In conclusion, neuropathic pain was not associated with small nerve fibre function, and sensory alteration was associated with both large and small fibre function. In addition, the standardized measurement of symptom severity, the SNCV and MNCV tests, and the VPT test appear to be useful for monitoring the course of polyneuropathy in clinical trials.

Lower limb muscle dysfunction may contribute to foot ulceration in diabetic patients

OBJECTIVES

To investigate the relationship between in-shoe plantar foot pressure and the co-ordinated activity of five lower limb muscles of diabetic patients, who are known to have a higher risk of foot morbidity.

DESIGN

A portable six channel electromyographic system has been designed, developed and synchronised in real time with a 16 channel piezoelectric transducer in-shoe pressure measuring device, Gaitscan.

BACKGROUND

So far, no one has tried to establish a relationship between in-shoe foot pressure distribution and muscle activity of the lower limb in diabetes. The measurement of phasic muscle activity has been related to foot pressure and compared to a control group of normal volunteers.

METHODS

Twenty nine diabetic subjects and 22 healthy non-diabetic volunteers have been studied by recording electromyography of lower leg muscles and in-shoe foot pressure measurements simultaneously.

RESULTS

In diabetic subjects, the period of contact pressure was greater than in normal control subjects (P<0.003). The initial forefoot time to contact with the ground was shorter in diabetics when compared to controls, indicating a faster forefoot contact. Of the dorsiflexor muscles, the Anterior Tibialis, normally contracting eccentrically at heel strike, was subject to a measurable delay in the initiation of contraction, of mean difference of 180 ms (P<0.001), in diabetic subjects when compared to the normal controls.

CONCLUSIONS

The late firing of Tibialis Anterior means that its normal modulating role in lowering the foot to the ground after heel strike through eccentric contraction is disturbed. The result is that the foot reaches the foot flat stage in a less ordered manner, subjecting it to high plantar pressures.

RELEVANCE

The results obtained may assist in planning realignment procedures of the foot and help prevent development of ulcers on the sole of the foot in high risk diabetic subjects.

Hardness of plantar skin in diabetic neuropathic feet

To evaluate if skin hardness in diabetic neuropathic feet was increased and if its eventual modifications could be correlated to the severity of neuropathy, we studied a group of diabetic outpatients with and without neuropathy. Patients, selected among those who were attending their routine screening for diabetic neuropathy at our diabetologic clinic, were divided into two groups according to the presence (ND+) or absence (ND-) of diabetic neuropathy with the criteria of the S. Antonio Consensus Conference on Diabetic Neuropathy. Patients then underwent an evaluation of vibration perception threshold (VPT) by means of a biotesiometer, measurement of skin hardness (DMT) by means of a durometer, and transcutaneous oxygen tension (TcPO2) determination. VPT was determined at allux (VPT-A) and external malleolus (VPT-M), DMT was measured at heel (DMT-H), at medial (DMT-M) and lateral (DMT-L) midfoot, and at posterior midcalf (DTM-C) as a control site; TcPO2 was evaluated at dorsum (TcPO2-D) and at medial midfoot (TcPO2-M), respectively. All measurements were performed on the nondominant side with the patients supine. Patients were compared with age and gender-matched healthy volunteers (Controls), who underwent the same evaluations in the same order. ND+ patients showed higher values of VPT than ND- and Controls, both at first toe and at malleolus analysis of variance (ANOVA) p<0.01), as well of DMT in all the three sites explored (ANOVA, p<0.01). Moreover, ND+ showed no difference in DMT among the sites, while both in ND- and in controls DMT-M was significantly (p<0.05) lower than DMT-H and DMT-L. No difference among the three groups were observed in TcPO2 measurements, and no difference in DMT-C was observed either. A significant correlation was observed between DMT-H and VPT-M (r2 = 0.516) and between DMT-M and VPT-A (r2 = 0.624) in ND+ patients. Skin hardness was diffusely increased in ND+ patients, and this increase strongly correlates with the severity of neuropathy. Simple, noninvasive determination of skin hardness could identify patient at potential risk to develop neuropathic foot ulcers.

End-stage complications of diabetic neuropathy: foot ulceration

Diabetic polyneuropathy is a major complication of diabetes mellitus that frequently leads to foot ulceration. Because of economic impact of foot ulceration and subsequent amputation, major initiatives are under way in the United States and the United Kingdom to reduce their incidence by up to 50%. Although diabetic ulcers may have an ischemic and neuropathic component, the majority are neuropathic. Results from studies have shown a strong association between the neuropathy and the subsequent development of foot ulcers. However, other predisposing factors such as high foot pressures, inappropriate footwear, and other extrinsic pressure usually must be present, together with neuropathy, to cause foot ulcers. Therefore, the challenge to the physician is to identify the patient at risk and intervene so as to educate and prevent the occurrence of foot ulcers.