Unchanged incidence of lower-limb amputations in a German City, 1990-1998

The diabetic foot

Diabetic foot problems are common throughout the world, resulting in major medical, social and economic consequences for the patients, their families, and society. Foot ulcers are more likely to be of neuropathic origin, and therefore eminently preventable. People at greatest risk of ulceration can easily be identified by careful clinical examination of the feet: education and frequent follow-up is indicated for these patients. When infection complicates a foot ulcer, the combination can be limb or life-threatening. Infection is defined clinically, but wound cultures assist in identifying the causative pathogens. Tissue specimens are strongly preferred to wound swabs for wound cultures. Antimicrobial therapy should be guided by culture results, and although such therapy may cure the infection, it does not heal the wound. Alleviation of the mechanical load on ulcers (offloading) should always be a part of treatment. Plantar neuropathic ulcers typically heal in 6 weeks with irremovable casting, because pressure at the ulcer site is mitigated and compliance is enforced. The success of other approaches to offloading similarly depends on the patients' adherence to the effectiveness of pressure relief.

The neuropathic diabetic foot

Diabetic foot problems are common throughout the world, and result in major medical, social and economic consequences for the patients, their families, and society. Foot ulcers are likely to be of neuropathic origin and, therefore, are eminently preventable. Individuals with the greatest risk of ulceration can easily be identified by careful clinical examination of their feet: education and frequent follow-up is indicated for these patients. When infection complicates a foot ulcer, the combination can be limb-threatening, or life-threatening. Infection is defined clinically, but wound cultures assist in identification of causative pathogens. Tissue specimens are strongly preferred to wound swabs for wound cultures. Antimicrobial therapy should be guided by culture results, and although such therapy may cure the infection, it does not heal the wound. Alleviation of the mechanical load on ulcers (offloading) should always be a part of treatment. Plantar neuropathic ulcers typically heal in 6 weeks with nonremovable casts, because pressure at the ulcer site is mitigated and compliance is enforced. The success of other approaches to offloading similarly depends on the patient's adherence to the strategy used for pressure relief.

Xerosis and callus formation as a key to the diabetic foot syndrome: Dermatologic view of the problem and its management

The diabetic foot syndrome is a major complication of diabetes mellitus. The two most important pathophysiologic factors are peripheral arterial occlusion and peripheral neuropathy. The cutaneous lesion is a plantar ulcer, often accompanied by soft tissue and bone infections which can require amputation. Triggers include poorly fitting shoes, poor foot care, or overlooked foreign bodies, often coupled with a structural foot deformity. Increased plantar pressure, especially beneath the metatarsal heads, and the resultant callus play an important role. The patients often already have xerosis of the plantar skin with scales, fissures, erosions and impaired barrier function, complicating the situation. Prompt neurologic and vascular diagnostic studies, coupled with routine examination of the feet and primary prophylactic measures are most important. The most important therapeutic goals are optimal control of the diabetes mellitus, relieving pressure points and avoiding or reducing callus formation.

Expression of matrix metalloproteinases and growth factors in diabetic foot wounds treated with a protease absorbent dressing

Wound healing in diabetes is impaired, and nonhealing ulceration represent clinically relevant complications. Persistently high levels of matrix metalloproteases (MMPs) contribute to wound chronicity. Thus, the topical use of protease inhibitors might influence wound healing and promote transition from a chronic to an acute wound.

METHODS

In this study, 33 patients with chronic diabetic foot lesions (stage 2a of the University of Texas Wound Classification system) were included. Fifteen patients received redundant "good standard wound care." In addition, 18 patients were treated with a protease inhibitory modulating matrix (the OCR/collagen Promogran matrix, Ethicon) with dressings changed on a daily basis. Prior to treatment and at 4 and 8 days after treatment, two 3-mm punch biopsies were taken from the center of the wounds and analyzed using ELISA techniques for MMPs, tissue inhibitor of MMP-2 (TIMP-2), and interleukin-1beta (IL-1beta) levels. In addition, mRNA levels of MMPs as well as IL-1beta and TNF-alpha were detected using quantitative real-time polymerase chain reaction (TaqMan, Applied Biosystems, Weiterstadt, Germany).

RESULTS

No differences were detected between both groups and at the three time points for the mRNA levels of MMPs as well as of IL-1beta and TNF-alpha. In addition, MMP levels in wound tissue (analyzed by ELISA) were also not significantly different between both groups. However, IL-1beta was increased on day 8 in the treatment group (P=.01) only. Interestingly, we found a significant reduction of the MMP-9/TIMP-2 ratio in the group being treated with the ORC/collagen. These wounds exhibited a more rapid healing rate when treated with the ORC/collagen matrix.

CONCLUSIONS

The local treatment with a protease inhibitor has a beneficial effect on wound healing. In contrast to the data on wound fluid, our study demonstrated for the first time the unaltered mRNA levels of MMPs during treatment with a protease inhibitory modulating matrix. At the cellular level, MMPs were also not statistically different. However, the more relevant ratio of MMP-9/TIMP-2 was decreased in the treatment group. An equally important finding was that we did not detect a compensatory increase in the MMP-RNA expression even though wound size was clearly reduced.

Diabetic foot screening: why is it neglected?

Understanding reasons for the neglect of foot screening during the annual review of people with diabetes enables the development of solutions for this omission. This study explores the reasons within the context of health care delivery systems in terms of the professional, social, political and economic aspects of this screening. Information was obtained through reviewing publications on diabetic foot and health care reform. The omission of annual foot examination for people with diabetes is attributed to the nature of diabetes-related foot problems, people with diabetes, health care professionals and the current structure of health care delivery systems. Increasing the adherence to foot screening for those with diabetes requires short- and long-term strategies. Short- and long-term strategies for reminding patients and staff about foot screening are suggested.

F. Fatores predisponentes para amputação de membro inferior em pacientes diabéticos internados com pés ulcerados no estado de Sergipe

OBJETIVO: Determinar os fatores predisponentes para a amputação de membros inferiores nos doentes internados com diabetes melito e úlceras nos pés. MÉTODOS: Foram acompanhados os pacientes diabéticos com úlceras nos pés internados no período de 6 meses e analisadas as amputações nesses doentes em relação à idade, sexo, amputação prévia, número de ulcerações, tempo de diagnóstico do diabete, tempo de ulceração, tempo médio de internação, gravidade das lesões, presença de pulso. RESULTADOS: Verificou-se que 55% (44/80) dos doentes evoluíram para algum tipo de amputação de membros inferiores; a mediana das idades foi de 61 anos, porém a ocorrência de amputação foi significativamente maior na faixa etária dos 60 aos 90 anos (P = 0,03). Não se observou uma variação significativa da mediana do tempo de diagnóstico do diabetes, do tempo de ulceração e do tempo médio de internação em relação ao grupo de pacientes que foram amputados. Entretanto, as lesões mais graves, quando avaliadas pela classificação de Wagner (P <0,001) e pela ausência de detecção dos dois pulsos distais (P <0,001) dos membros inferiores, revelaram-se bastante significativas com relação ao desfecho de amputação. CONCLUSÃO: Foram considerados fatores predisponentes para a ocorrência de amputação nesses doentes a gravidade das lesões, a ausência de pulsos e as idades acima de 60 anos.

The global burden of diabetic foot disease

Diabetic foot problems are common throughout the world, resulting in major economic consequences for the patients, their families, and society. Foot ulcers are more likely to be of neuropathic origin, and therefore eminently preventable, in developing countries, which will experience the greatest rise in the prevalence of type 2 diabetes in the next 20 years. People at greatest risk of ulceration can easily be identified by careful clinical examination of the feet: education and frequent follow-up is indicated for these patients. When assessing the economic effects of diabetic foot disease, it is important to remember that rates of recurrence of foot ulcers are very high, being greater than 50% after 3 years. Costing should therefore include not only the immediate ulcer episode, but also social services, home care, and subsequent ulcer episodes. A broader view of total resource use should include some estimate of quality of life and the final outcome. An integrated care approach with regular screening and education of patients at risk requires low expenditure and has the potential to reduce the cost of health care.

Rapid healing of intractable diabetic foot ulcers with exposed bones following a novel therapy of exposing bone marrow cells and then grafting epidermal sheets

BACKGROUND

Diabetic foot ulcers with exposed bones commonly result in amputation.

OBJECTIVES

To determine whether exposure of bone marrow cells and subsequent grafting of epidermal sheets accelerates healing and reduces the need for amputation.

METHODS

Thirty-eight patients with chronic wounds caused by diabetes mellitus were enrolled in this study. Epidermal sheets obtained from suction blisters of each patient were grafted on to diabetic foot ulcers without exposed bones (n = 10) and were compared with the standard treatment of local wound care, debridement with a scalpel when indicated, bed rest and parenteral antibiotics (n = 8). In another group of patients, diabetic wounds with exposed bones were treated either with the standard procedure (n = 9) or with a newly developed experimental procedure (n = 11). In that new procedure, the affected bone was initially exposed by debridement with a scalpel, followed by partial excision with a bone scraper until fresh bleeding was observed from the exposed bone. The lesions were then immediately covered with an occlusive dressing, and finally the wound was covered with an epidermal graft of skin harvested from suction blisters. Patients in each group were matched with their counterparts by age, sex, wound size, wound infection and wound duration, to compare the time needed for total skin repair and rates of amputation.

RESULTS

Epidermal grafting significantly accelerated the healing of diabetic foot ulcers (P = 0.042) without exposed bones, with site-specific differentiation. The newly developed combination therapy resulted in the healing of all diabetic ulcers with exposed bones without the occurrence of osteomyelitis or the necessity for amputation (P < 0.0001).

CONCLUSIONS

Our study indicates that early aggressive debridement of diabetic foot ulcers with exposed bones down to a bleeding vascularized base and then grafting epidermal sheets significantly improves healing and reduces the rate of amputation.

[Diffusion of ulcers in the diabetic foot is promoted by stiffening of plantar muscular tissue under excessive bone compression]

The abnormally elevated plantar pressures under the bony prominences of the diabetic foot (mainly under the medial metatarsal heads and calcaneus) were associated with intensified internal stresses in the deep soft tissues padding these bones. In this study, we tested changes in mechanical properties of muscular tissue after exposure to the internal stress levels typically developing under the first and second metatarsal heads in the load bearing diabetic foot (40-80 KPa). The gracilis muscles of anesthetized rats were subjected to constant external pressures of 35 and 70 KPa for 2 h, which caused average internal compression stresses of 40 and 80 KPa, respectively, within the living gracilis. The animals were then killed and the tangent elastic moduli of the harvested gracilis were measured in uniaxial tension at strains of 2.5%, 5% and 7.5%. Tangent moduli of gracilis muscles exposed to internal compression of 40-80 KPa in vivo ( n=6) were 1.6-fold stiffer ( p<0.05) than those of controls ( n=6). These abnormally stiff mechanical properties were incorporated into a finite element (FE) model of the plantar tissue under the second ray of the foot, and were shown to increase the magnitude of deep internal stresses and project elevated stresses to larger regions. Hence, the integration of animal model data with FE simulations indicates a mechanism of plantar tissue deterioration in the diabetic foot, where muscles exposed to critical stresses respond with increased stiffness which then further intensifies the deep plantar stresses. This suggests a new positive feedback mechanism for the diffusion of ulcers and the atrophy of intrinsic plantar muscles in the diabetic foot, where the injury spreads from deep muscles to the skin surface by an evolving mechanical stress wave.

Amputation as a marker of the quality of foot care in diabetes

Strategic targets for the management of foot ulcers focus on reducing the incidence of amputation. While data on the incidence of amputation can be obtained relatively easily, the figures require very careful interpretation. Variation in the definition of amputation, population selection and the choice of numerator and denominator make comparisons difficult. Major and minor amputation have to be distinguished as they are undertaken for different reasons and are associated with different costs and functional implications. Many factors influence the decision of whether or not to remove a limb. In addition to disease severity, co-morbidities, and social and individual patient factors, many aspects of the structure of care services affect this decision, including access to primary care, quality of primary care, delays in referral, availability and quality of specialist resources, and prevailing medical opinion. It follows that a high incidence of amputation can reflect a higher disease prevalence, late referral, limited resources, or a particularly interventionist approach by a specialist team. Conversely, a low incidence of amputation can indicate a lower disease prevalence or severity, good management of diabetes in primary and secondary care, or a particularly conservative approach by an expert team. An inappropriately conservative approach could conceivably enhance suffering by condemning a person to months of incapacity before they die with an unhealed ulcer. The reported annual incidence of major amputation in industrialised countries ranges from 0.06 to 3.83 per 10(3) people at risk. Some centres have documented that the incidence is falling, but this is often from a baseline value that was unusually high. Other centres have reported that the incidence has not changed. The ultimate target is to achieve not only a decrease in incidence, but also a low overall incidence. This must be accompanied by improvements in morbidity, mortality, and patient function and mood.

The diabetic foot: from art to science. The 18th Camillo Golgi lecture

Diabetic foot ulceration represents a major medical, social and economic problem all over the world. While more than 5% of diabetic patients have a history of foot ulceration, the cumulative lifetime incidence may be as high as 15%. Ethnic differences exist in both ulcer and amputation incidences, with both being less common in patients of Indian subcontinent origin living in the UK. Foot ulceration results from the interaction of several contributory factors, the most important of which is neuropathy. With respect to the management of acute Charcot neuroarthropathy in diabetes, recent studies suggest that bisphosphonates reduce disease activity as judged not only by differences in skin temperature, but also by assessing markers of bone turnover. The use of the total-contact cast is demonstrated in the treatment of acute Charcot feet and of plantar neuropathic ulcers. Histological evidence suggests that pressure relief results in chronic foot ulcers changing their morphological appearance by displaying some features of an acute wound. Thus, repetitive stresses on the insensate foot appear to play a major role in maintaining ulcer chronicity. It is hoped that increasing research activity in foot disease will ultimately result in fewer ulcers and less amputation in diabetes.

Treatment of diabetic foot lesions in hospital: results of 2 successive five-year periods, 1989-1993 and 1994-1998

OBJECTIVES

To assess the impact of an educational training program we initiated in 1994 for GPs about diabetic foot ulcer (DFU) management, we compared the rate and level of lower limb amputation (LLA) in diabetic patients performed in our unit between two consecutive five-year periods, 1989-1993 and 1994-1998.

PATIENTS AND METHODS

During the first period, 132 patients with 163 lesions (9.2% of the total admissions for diabetes) were compared with 176 with 183 lesions (10.5%) during the second period. Patients' mean age was the same in both periods: 59.6 +/- 11.7 in 1989-1993 and 58.3 +/- 13.1 in 1994-1998 [Not statistically significant, NS].

RESULTS

Patients age, sex ratio, type of diabetes and severity of the lesion (as assessed according to Wagner classification) were essentially the same during the two periods. Most of the foot lesions ( approximately 90%) were purely neuropathic or neuro-ischaemic, with no change in repartition between the two periods. Primary healing was 59.1% in the 1st period and 56.8% in the second. No change in minor and major amputation rate was observed between the 1st period (14.4 and 15.9%, respectively) and the second (11.4 and 16.5%, respectively). The in-hospital mortality rate was unchanged (9.1 vs 8.5%, NS), while the percentage of patients who left hospital against medical advice and dropped out of follow up increased from 1.5 to 6.8% (p<0.04). Mean length of hospitalisation was identical, about 43 days.

CONCLUSIONS

In spite of implementing educational program for GPs, no improvement in the DFU management was noted as emphasised by absence of any significant change in amputation rate before (1st period) and after initiating the program (2nd period). These disappointing results can be explained by several factors: weakness of our educational program, lack of motivation from GPs, absence of a structured multidisciplinary prevention approach. The main problem, common to developing countries, remains the insufficiency of financial resources. Moreover, civil disturbances can make the problem more difficult to manage, as in Algeria since 1991.

Reduction in diabetes-related lower-extremity amputations in The Netherlands: 1991-2000

OBJECTIVE

Lower-extremity amputation is a common complication among patients with diabetes throughout the world. However, few data exist on the actual impact of the recent moves to improve the management of diabetic foot ulcers to reduce the incidence of lower-extremity amputations. The aim was to determine the incidence of lower-extremity amputations among diabetic patients from 1991 to 2000 in The Netherlands.

RESEARCH DESIGN AND METHODS

A secondary database containing information regarding all hospital admissions in which a lower-extremity amputation occurred for the years 1991-2000 was obtained from the Dutch National Medical Register. Because a patient-unique identifier was included, multiple amputations and hospitalizations for a single individual could be identified. Furthermore, age- and sex-specific diabetes prevalence rates were calculated using a 3-year average for every year, calculating the total diabetic population in the Netherlands at risk for every year.

RESULTS

In 1991, a total of 1,687 patients with diabetes had been admitted 1,865 times for 2,409 amputations. In 2000, a total of 1,673 patients with diabetes were admitted 1,932 times for 2,448 amputations. The overall incidence rates of the number of patients who underwent lower-extremity amputation decreased over the years from 55.0 to 36.3 per 10,000 patients with diabetes (P < 0.05). Both in men (71.8 vs. 46.1, P < 0.05) and women (45.0 vs. 28.0, P < 0.05) with diabetes, a significant decrease could be observed. Mean duration of hospitalization decreased from 45.0 days (SD 44.4) in 1991 to 36.2 days (SD 38.4) in 2000; decreases were observed for both men and women.

CONCLUSIONS

Over the years observed in this study, the incidence rates of diabetes-related lower-extremity amputation in The Netherlands was found to decrease in both men (36%) and women (38%) with diabetes. Furthermore, the duration of hospitalization decreased over time.

Diabetic foot ulcers

Ulceration of the foot in diabetes is common and disabling and frequently leads to amputation of the leg. Mortality is high and healed ulcers often recur. The pathogenesis of foot ulceration is complex, clinical presentation variable, and management requires early expert assessment. Interventions should be directed at infection, peripheral ischaemia, and abnormal pressure loading caused by peripheral neuropathy and limited joint mobility. Despite treatment, ulcers readily become chronic wounds. Diabetic foot ulcers have been neglected in health-care research and planning, and clinical practice is based more on opinion than scientific fact. Furthermore, the pathological processes are poorly understood and poorly taught and communication between the many specialties involved is disjointed and insensitive to the needs of patients.

Amputations and diabetes: a case-control study

AIMS

Data concerning the relative risk of amputations in diabetic patients compared with the general population are scarce. Therefore, we carried out a case control study to quantify the relationship between diabetes and amputations.

METHODS

In 20 hospitals in seven German cities and counties we obtained complete lists of non-traumatic lower limb amputations performed in 1990 and 1991. CONTROLS were selected from patients of the same surgical departments operated on in the same years. We drew a random sample of patients with procedures not likely to be associated with diabetes. Diabetic status was determined from patients' records in both cases and controls. We calculated age- and sex-specific and, using logistic regression, adjusted odds ratios (OR) and attributable risks.

RESULTS

N = 2400, mean age 61.7 (SD 16.3) years.

CASES

n = 729; 486 (66.7%) of them had diabetes.

CONTROLS

n = 1671; 127 (7.6%) of them had diabetes. Adjusted OR: 18.2 (confidence interval (CI) 14.2-23.6). Adjusted attributable risk among exposed (ARE): 0.95 (CI 0.93-0.96). Adjusted population attributable risk (PAR): 0.62 (CI 0.57-0.66).

CONCLUSIONS

This study has demonstrated a strong association between the risk of amputation and diabetes. The odds ratios and attributable risks for diabetic individuals are higher in the younger than in the older age groups. Population attributable risks are great. We conclude that the reduction of amputations in the general population will be achieved by improving foot care in people with diabetes.