Multimodal approach of Foot & Ankle clinic on Diabetic Foot infections

Up until the last 5-8 years or so there was a little lack of attention to Diabetic Foot infections. But, now the entire scenario has changed dramatically. Diabetic foot care is teamwork that aims at detecting signs that could bring the diabetic foot at risk of Ulcerations’ The elements that can be quantified are Pressure on the feet, the planter blood flow, the sensitivity of feet. The role of this article is to bring to all about the recent update on the topic as the preventing efforts are well known to maintain an intact foot. There is evidence that appropriate footwear reduces plantar pressure and can help to heal the ulcer. The neuropathies are among the most common long-term complications of diabetes mellitus, affecting up to half of the patients. The socio-economic burden the diabetic foot causes on the country’s resources is tremendous.

In India point prevalence of foot ulcers in diabetes in the clinic population is 3%, which is much lower than reported in the western world. Younger age and shorter duration of Diabetes may be a possible reason for low prevalence here in our country. The peripheral vascular disease has been reported to be low among Asians ranging between 3 and 6 % as against 25 and 45 % in western patients. The prevalence also increases with increased duration of Diabetes, 15% at 10 years and 45% after 20 years. Although population-based data are not available, rough estimates indicate that in India approximately 45,000 legs are amputated every year, and the numbers are increasing each year.

The spectrum of disorders affecting the Diabetic Foot

1 Ischaemia

A. Non –specific atherosclerosis.

B. Specific diabetes microangiopathy

2 Neuropathy

A. Motor

B .Sensory

C. Autonomic – Sudomotor and Vasomotor

3 Infection-Increased Susceptibility to infection.

Fungal infection of the foot is also more common in diabetes; where this occurs it must be controlled, as the small epidermal erosions & fissures can provide a portal of entry to more virulent organisms leading to cellulitis and possible gangrene of the toes.

Classification of Diabetic Foot Ulcers

Many attempts have been made to classify diabetic foot ulcerations. Probably the most commonly used system was introduced by Wagner. This system, which originally addressed only the dysvascular foot, does not adequately address all diabetic foot ulcerations and infections. Most diabetic foot complications occur because of neuropathy, not ischemia. Wagner classification is based on the depth of ulcer. The University of Texas classification is the same as the depth-ischemia classification with consideration of infection.

Stage A- Ulcer which is neither infected ulcer nor ischemic.

Stage B- Infected ulcer but not ischemic.

Stage C- Ischemic but not infected.

Stage D-Both Ischemic and infected.

Actually, the outcome of Ulcer mainly depends on Ischemia & infection, not on Depth.

Wegeners Classification:

Grade 0: High-risk foot with no ulceration/ Impending Ulcer

Grade 1:superficial Ulcer

Grade 2: Deep ulceration penetrating up to tendon, bone, or even joint.

Grade 3:Osteomyelitis

Grade 4: Localized Gangrene of Toes/Forefoot/Hindfoot.

Grade5: Gangrene of Entire Foot

Two types of Diabetic Foot can be seen:

A Neuropathic foot-Here neuropathy dominates which may lead to fissures, bullae, neuropathic/charcot joint, or even simple neuropathic Oedema

B Neuroischaemic foot- Here along with neuropathy, occlusive vascular disease is the main factor.

Management:

A multidisciplinary team of Diabetologist, Orthopaedic surgeons, Podiatrists should be there for managing such cases. A perfect Medical & surgical approach should be planned.

Infectious Diseases Society of America(IDSA) has proposed Guidelines for the Diagnosis and Treatment of Diabetic Foot infections that clearly define the clinical and laboratory features that distinguish a mild infection from moderate /severe infection. This is a useful tool for grading foot infections. This classification is especially useful for predicting the organisms one can expect to find in a given situation thus allowing one to start appropriate empirical treatment before culture and sensitivity results are known.

Foot and Ankle Clinics are coming up very fast in our country. These clinics have a Diabetic Foot unit which comprises various subunits to take care of the evaluation part. Vascular evaluation can be done by Digital colour Doppler. Neurological evaluation for early neuropathic changes can be done by Biothesiometer. It helps us to quantitate the vibration perception threshold and at the same time can monitor the progressing neurological changes. Further for detecting changes in sensation of Heat, cold & Pain stimulus HCP sensitometer is used. Pressure point evaluation by Foot Scan can be done. Later according to the pressure points Off Loading Orthosis can be planned. Off LoadingDiabetic shoes are useful in the treatment of Ulcerative or pre ulcerative conditions of Foot. It is a good option when total contact casting is not an option. These shoes have a Tri-laminate IMPAX grid insole which is designed to redistribute load away from Ulcers.

A. Non Healing Diabetic ulcer

B. Same patient with Calcification of Anterior & Posterior Tibial Artery( Severe Peripheral Disease is the reason for nonhealing

Role of Pseudomonas aeruginosa and MRSA : In one of the largest studies of moderate -to severe diabetic foot infections, the study of Infections in Diabetic Feet comparing Efficacy, Safety, and Tolerability of Ertapenem versus Piperacillin/Tazobactum (SIDESTEP study), Lipsy and Colleagues recruited 576 patients to a randomized,double-blinded, multicenter trial.289 patients were assigned to receive 1gm of Ertapenam and 287 patients received 3.375 g four times daily of piperacillin/tazobactam. The clinical success rate after the end of therapy was 94.2% in the Ertapenam group and 92.2% for the piperacillin/tazobactam group. Based on this trial, Ertapenem received an FDA indication for treatment of Diabetic foot infections.

Inadequately diagnosed or treated osteomyelitis increases the risk for amputation. A thorough preoperative examination is necessary to maximize treatment outcomes. Optimal medical control of diabetes and associated comorbidities is essential before foot& ankle surgery is undertaken. The treatment of diabetic patients who have large ulcers and underlying osteomyelitis is not enough well described in the current Literature. However, currently, there are only a few reports describing salvage of diabetic foot with external fixation in the literature. Surgeons worldwide have been using external fixators for all types of fracture management, arthrodesis, complex deformities. In addition, procedures such as repeated debridements, skin grafting, dressing changes can be performed without disturbing the fixator. However the surgical technique differs in terms of the anatomical location of the ulcer, soft-tissue defect, and osteomyelitis for example a multiplaner illizarov /JESS external fixation can decrease the soft-tissue defect in the equines position of the ankle. Fixator is usually removed after between 6-8 weeks. Patients subsequently ambulate in a polypropylene splint with plastizote and foam filler in the region of heel defect.

Diabetic Foot unit can handle clinical orthopaedic problems as Infections, ulcerations, Charcot’s joint, and worst to worst amputation if mandatory. Three factors must be considered while managing such neuropathic ulcers which are –How deep are the Ulcers? Is it ischemic.? Is it infected? The most common operative procedure for neuropathic deformity is the removal of bony prominence (Ostectomy)on the medial, lateral, or plantar aspect of the foot that is creating recurrent ulcerations and difficulty with Footwear. Management of the diabetic wound has improved dramatically in the last decade. With the advent and clinical application of recombinant chemical and cellular mediators of wound healing, most foot wounds can be healed with little morbidity. Newer dressings materials for particular type of wounds are required such as hydrogels, hydrocolloids, alginate.

Newer therapies provide various growth factors topically, to promote and hasten wound healing. Newer dressings materials for a particular type of wound are required such as hydrogels, hydrocolloids, alginate. Often, the primary impediments to healing include inadequate blood flow to the wound, and impediments to healing include inadequate blood flow to the wound (as in above mentioned radiograph) and an alteration in the local biologic milieu. For these patients, advanced wound healing technologies, orthobiologics and bioengineered alternative tissues(BAT) may tilt the scales in the direction of definitive wound closure. BAT and topically applied platelet preparations are two of the newer technologies available. Both act to stimulate the conversion of a chronic wound to an acute wound and are used in the treatment of many problematic wound types and locations.

BAT products rely on an environment that has an adequate blood supply, therefore, vascular studies examining the level of ischemia to the affected limb should always be considered when treating a chronic wound and applying BAT products. Optimization of the wound environment before the application of the BAT products will ensure a successful wound closure. The growth factors are most commonly involved in wound healing, angiogenesis. Inflammatory cells and cells that make up the skin contain these growth factors as platelet-derived growth factor(PDGF), fibroblast growth actor (FGF), epidermal growth factor(EGF) and insulin-like growth factor(IGF). Living cell-based BAT products generally stimulate wound healing process or can deliver growth factors extrinsically when applied to the wound. Some BAT contains contain living fibroblasts and keratinocytes in addition to growth factors. When selecting a particular BAT product, it is important to keep in mind the different layers of tissue and their architecture.

Summary

Diabetic Foot should be managed using a multidisciplinary team approach which should comprise Diabetologist, Orthopaedic Surgeon, Podiatrist, Orthotist. Sometimes even the help of Vascular surgeon is taken. The motto of the team is to save the Foot, not to amputate it. A number of surgical techniques can maximize the success of wound healing. There is an urgent need to develop a Diabetic foot care team working in Diabetic Foot clinics where an integrated approach in managing varied clinical presentations of the diabetic foot should be made. A well organized Diabetic Foot clinic should provide consistent patient education as well as preventive and acute care of Diabetic Foot lesions

References

1 Stokes IAF ,Faris IB Hutton WC: The neuropathic ulcer and the loads on the foot in diabetic patients.Acta orthop scand 46: 839-847,1975.

2 valente LA,Nelson MS: patient Education for diabetic Patients.An integral part of quality health care.J Am Podiatr Med Assoc 85:177,1975

3 Pendsey SP ,Epidemiological aspects of diabetic foot .Int j Diab. Dev Counteries 1994;14:37-8

4 International consensus on the Diabetic Foot,by international working on the Diabetic Foot,1999.

5 Mohan V, Premlatha G.Sastry N G. Peripheral vascular disease in Noninsulin dependent diabetes mellitus in south India.Diab Res Clin Pract 1995 ; 27:235-40.

6 Pensey Sharad. Diabetic Foot. A clinical atlas. Jaypee Brothers,N Delhi;2003

7 Wagner FW. The dysvascular foot: a system for diagnosis and treatment.foot Ankle 1981;2(2):64-122

8 Michael E,Edmonds, Alethea VM Foster(Eds). Managing the Diabetic Foot. Blackwell Science:2000;123-5

9 Lipsy BA, Armstrong DG, Citron DM, etal. Ertapenem versus Piperacillin/Tazobactum (SIDESTEP ).Lancet 2005;366(9498):1695-703.

10 Attinger CE, Bulan EJ, Debridement: the Key initial step in wound healing.Foot Ankle Clinic 2001;6:627-60

11 Brem H, Sheehan P, Boulton AJM, Protocal for treatment of diabetic foot ulcers. AM J Surg 2004;187(suppl): IS-10S

Up until the last 5-8 years or so there was a little lack of attention to Diabetic Foot infections. But, now the entire scenario has changed dramatically. Diabetic foot care is teamwork that aims at detecting signs that could bring the diabetic foot at risk of Ulcerations’ The elements that can be quantified are Pressure on the feet, the planter blood flow, the sensitivity of feet. The role of this article is to bring to all about the recent update on the topic as the preventing efforts are well known to maintain an intact foot. There is evidence that appropriate footwear reduces plantar pressure and can help to heal the ulcer. The neuropathies are among the most common long-term complications of diabetes mellitus, affecting up to half of the patients. The socio-economic burden the diabetic foot causes on the country’s resources is tremendous.

In India point prevalence of foot ulcers in diabetes in the clinic population is 3%, which is much lower than reported in the western world. Younger age and shorter duration of Diabetes may be a possible reason for low prevalence here in our country. The peripheral vascular disease has been reported to be low among Asians ranging between 3 and 6 % as against 25 and 45 % in western patients. The prevalence also increases with increased duration of Diabetes, 15% at 10 years and 45% after 20 years. Although population-based data are not available, rough estimates indicate that in India approximately 45,000 legs are amputated every year, and the numbers are increasing each year.

The spectrum of disorders affecting the Diabetic Foot

1 Ischaemia

A Non –specific atherosclerosis.

B Specific diabetes microangiopathy

2 Neuropathy

A Motor

B Sensory

C Autonomic – Sudomotor and Vasomotor

3 Infection-Increased Susceptibility to infection.

Fungal infection of the foot is also more common in diabetes; where this occurs it must be controlled, as the small epidermal erosions & fissures can provide a portal of entry to more virulent organisms leading to cellulitis and possible gangrene of the toes.

Classification of Diabetic Foot Ulcers

Many attempts have been made to classify diabetic foot ulcerations. Probably the most commonly used system was introduced by Wagner. This system, which originally addressed only the dysvascular foot, does not adequately address all diabetic foot ulcerations and infections. Most diabetic foot complications occur because of neuropathy, not ischemia. Wagner classification is based on the depth of ulcer. The University of Texas classification is the same as the depth-ischemia classification with consideration of infection.

Stage A- Ulcer which is neither infected ulcer nor ischemic.

Stage B- Infected ulcer but not ischemic.

Stage C- Ischemic but not infected.

Stage D-Both Ischemic and infected.

Actually, the outcome of Ulcer mainly depends on Ischemia & infection, not on Depth.

Wegeners Classification:

Grade 0: High-risk foot with no ulceration/ Impending Ulcer

Grade 1:superficial Ulcer

Grade 2: Deep ulceration penetrating up to tendon, bone, or even joint.

Grade 3:Osteomyelitis

Grade 4: Localized Gangrene of Toes/Forefoot/Hindfoot.

Grade5: Gangrene of Entire Foot

Two types of Diabetic Foot can be seen:

A Neuropathic foot-Here neuropathy dominates which may lead to fissures, bullae, neuropathic/ charcot joint, or even simple neuropathic Oedema

B Neuroischaemic foot- Here along with neuropathy, occlusive vascular disease is the main factor.

Management:

A multidisciplinary team of Diabetologist, Orthopaedic surgeons, Podiatrists should be there for managing such cases. A perfect Medical & surgical approach should be planned.

Infectious Diseases Society of America(IDSA) has proposed Guidelines for the Diagnosis and Treatment of Diabetic Foot infections that clearly define the clinical and laboratory features that distinguish a mild infection from moderate /severe infection. This is a useful tool for grading foot infections. This classification is especially useful for predicting the organisms one can expect to find in a given situation thus allowing one to start appropriate empirical treatment before culture and sensitivity results are known.

Foot and Ankle Clinics are coming up very fast in our country. These clinics have a Diabetic Foot unit which comprises various subunits to take care of the evaluation part. Vascular evaluation can be done by Digital colour Doppler. Neurological evaluation for early neuropathic changes can be done by Biothesiometer. It helps us to quantitate the vibration perception threshold and at the same time can monitor the progressing neurological changes. Further for detecting changes in sensation of Heat, cold & Pain stimulus HCP sensitometer is used. Pressure point evaluation by Foot Scan can be done. Later according to the pressure points Off Loading Orthosis can be planned. Off LoadingDiabetic shoes are useful in the treatment of Ulcerative or pre ulcerative conditions of Foot. It is a good option when total contact casting is not an option. These shoes have a Tri-laminate IMPAX grid insole which is designed to redistribute load away from Ulcers.

A. Non Healing Diabetic ulcer

B. Same patient with Calcification of Anterior & Posterior Tibial Artery( Severe Peripheral Disease is the reason for nonhealing

Role of Pseudomonas aeruginosa and MRSA : In one of the largest studies of moderate -to severe diabetic foot infections, the study of Infections in Diabetic Feet comparing Efficacy, Safety, and Tolerability of Ertapenem versus Piperacillin/Tazobactum (SIDESTEP study), Lipsy and Colleagues recruited 576 patients to a randomized,double-blinded, multicenter trial.289 patients were assigned to receive 1gm of Ertapenam and 287 patients received 3.375 g four times daily of piperacillin/tazobactam. The clinical success rate after the end of therapy was 94.2% in the Ertapenam group and 92.2% for the piperacillin/tazobactam group. Based on this trial, Ertapenem received an FDA indication for treatment of Diabetic foot infections.

Inadequately diagnosed or treated osteomyelitis increases the risk for amputation. A thorough preoperative examination is necessary to maximize treatment outcomes. Optimal medical control of diabetes and associated comorbidities is essential before foot& ankle surgery is undertaken. The treatment of diabetic patients who have large ulcers and underlying osteomyelitis is not enough well described in the current Literature. However, currently, there are only a few reports describing salvage of diabetic foot with external fixation in the literature. Surgeons worldwide have been using external fixators for all types of fracture management, arthrodesis, complex deformities. In addition, procedures such as repeated debridements, skin grafting, dressing changes can be performed without disturbing the fixator. However the surgical technique differs in terms of the anatomical location of the ulcer, soft-tissue defect, and osteomyelitis for example a multiplaner illizarov /JESS external fixation can decrease the soft-tissue defect in the equines position of the ankle. Fixator is usually removed after between 6-8 weeks. Patients subsequently ambulate in a polypropylene splint with plastizote and foam filler in the region of heel defect.

Diabetic Foot unit can handle clinical orthopaedic problems as Infections, ulcerations, Charcot’s joint, and worst to worst amputation if mandatory. Three factors must be considered while managing such neuropathic ulcers which are –How deep are the Ulcers? Is it ischemic.? Is it infected? The most common operative procedure for neuropathic deformity is the removal of bony prominence (Ostectomy)on the medial, lateral, or plantar aspect of the foot that is creating recurrent ulcerations and difficulty with Footwear. Management of the diabetic wound has improved dramatically in the last decade. With the advent and clinical application of recombinant chemical and cellular mediators of wound healing, most foot wounds can be healed with little morbidity. Newer dressings materials for particular type of wounds are required such as hydrogels, hydrocolloids, alginate.

Newer therapies provide various growth factors topically, to promote and hasten wound healing. Newer dressings materials for a particular type of wound are required such as hydrogels, hydrocolloids, alginate. Often, the primary impediments to healing include inadequate blood flow to the wound, and impediments to healing include inadequate blood flow to the wound (as in above mentioned radiograph) and an alteration in the local biologic milieu. For these patients, advanced wound healing technologies, orthobiologics and bioengineered alternative tissues(BAT) may tilt the scales in the direction of definitive wound closure. BAT and topically applied platelet preparations are two of the newer technologies available. Both act to stimulate the conversion of a chronic wound to an acute wound and are used in the treatment of many problematic wound types and locations.

BAT products rely on an environment that has an adequate blood supply, therefore, vascular studies examining the level of ischemia to the affected limb should always be considered when treating a chronic wound and applying BAT products. Optimization of the wound environment before the application of the BAT products will ensure a successful wound closure. The growth factors are most commonly involved in wound healing, angiogenesis. Inflammatory cells and cells that make up the skin contain these growth factors as platelet-derived growth factor(PDGF), fibroblast growth actor (FGF), epidermal growth factor(EGF) and insulin-like growth factor(IGF). Living cell-based BAT products generally stimulate wound healing process or can deliver growth factors extrinsically when applied to the wound. Some BAT contains contain living fibroblasts and keratinocytes in addition to growth factors. When selecting a particular BAT product, it is important to keep in mind the different layers of tissue and their architecture.

Summary

Diabetic Foot should be managed using a multidisciplinary team approach which should comprise Diabetologist, Orthopaedic Surgeon, Podiatrist, Orthotist. Sometimes even the help of Vascular surgeon is taken. The motto of the team is to save the Foot, not to amputate it. A number of surgical techniques can maximize the success of wound healing. There is an urgent need to develop a Diabetic foot care team working in Diabetic Foot clinics where an integrated approach in managing varied clinical presentations of the diabetic foot should be made. A well organized Diabetic Foot clinic should provide consistent patient education as well as preventive and acute care of Diabetic Foot lesions

References

1 Stokes IAF ,Faris IB Hutton WC: The neuropathic ulcer and the loads on the foot in diabetic patients.Acta orthop scand 46: 839-847,1975.

2 valente LA,Nelson MS: patient Education for diabetic Patients.An integral part of quality health care.J Am Podiatr Med Assoc 85:177,1975

3 Pendsey SP ,Epidemiological aspects of diabetic foot .Int j Diab. Dev Counteries 1994;14:37-8

4 International consensus on the Diabetic Foot,by international working on the Diabetic Foot,1999.

5 Mohan V, Premlatha G.Sastry N G. Peripheral vascular disease in Noninsulin dependent diabetes mellitus in south India.Diab Res Clin Pract 1995 ; 27:235-40.

6 Pensey Sharad. Diabetic Foot. A clinical atlas. Jaypee Brothers,N Delhi;2003

7 Wagner FW. The dysvascular foot: a system for diagnosis and treatment.foot Ankle 1981;2(2):64-122

8 Michael E,Edmonds, Alethea VM Foster(Eds). Managing the Diabetic Foot. Blackwell Science:2000;123-5

9 Lipsy BA, Armstrong DG, Citron DM, etal. Ertapenem versus Piperacillin/Tazobactum (SIDESTEP ).Lancet 2005;366(9498):1695-703.

10 Attinger CE, Bulan EJ, Debridement: the Key initial step in wound healing.Foot Ankle Clinic 2001;6:627-60

11 Brem H, Sheehan P, Boulton AJM, Protocal for treatment of diabetic foot ulcers. AM J Surg 2004;187(suppl): IS-10S

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