A systematic approach to diabetic foot infections

Evidence based review of literature on detriments to healing of diabetic foot ulcers

BACKGROUND

Diabetes mellitus places a substantial burden on society worldwide. Diabetic foot ulcers are a challenging problem for clinicians. Seven generally accepted detriments to healing of diabetic foot ulcers were identified: infection, glycaemic control, vascular supply, smoking, nutrition, deformity and offloading. The aim of this paper is to present a comprehensive evidence based review of the literature available on detriments to healing of diabetic foot ulcers.

METHOD

A research question was generated for each of the detriments to healing and a comprehensive review of the literature was performed using the Pubmed database in July 2014. All articles were assessed for relevancy and a level of evidence was assigned. An analysis of the total body of literature was used to assign a grade of recommendation to each detriment.

RESULTS

Grade A recommendation was assigned to offloading as there was good evidence supporting this intervention. Grade B recommendation was assigned to deformity as there was fair evidence consistent with the hypothesis. Infection and vascular supply had poor quality evidence supporting the research question and grade C recommendation was assigned. Grade I recommendation was assigned to glycaemic control, smoking and nutrition as there was insufficient and conflicting evidence available.

CONCLUSION

Our literature review revealed good evidence for some factors and insufficient literature on others. Further studies are needed to provide quality evidence regarding detriments to healing of diabetic ulcers.

Results of One-Stage or Staged Amputations of Lower Limbs Consequent to Critical Limb Ischemia and Infection

BACKGROUND

Amputations of lower limbs can be conducted as one-stage amputation (OSA) or staged amputation (SA) procedures. The objective of this study was to analyze technical success and mortality rates of both techniques, as well as factors that might influence outcomes in patients with critical limb ischemia (CLI).

METHODS

A retrospective study of 185 consecutive patients with CLI who underwent amputations in the period 2004-2011. Primary end points were rates of technical success (healing without dehiscence or reintervention) and mortality. The influence on outcomes of demographic data, clinical status, and comorbidities was also analyzed by logistic regression.

RESULTS

A total of 101 SA (91 patients) and 106 OSA (94 patients) were analyzed. SA had proportionally higher success rate (SA 77.2% vs. OSA 66.0%, P = 0.0253), lower perioperative mortality rate (SA, 10.9% vs. OSA, 20.7%, P = 0.0247), and lower 30-day mortality rate (SA, 12.2% vs. OSA, 23.8%, P = 0.0220) in spite of more cases with Rutherford classes 5 and 6 (SA, 87.1% vs. OSA, 72.6%, P = 0.0047), diabetes (71.2% vs. 55.6%, P = 0.0076), and infection (44.5% vs. 28.3%, P = 0.0061). Logistic regression demonstrated that in SA, success was more frequent in patients with diabetes who did not use insulin (P = 0.0072), in those with transfemoral amputations (P = 0.0392), with no coronary artery disease (P = 0.0053), and in foot infection (P = 0.0446), while for OSA success was more frequent in nondiabetic patients (P = 0.0077), limbs without infection (P = 0.0298), amputations at foot level (P = 0.0155), or transfemoral amputations (P = 0.0030).

CONCLUSIONS

SA had a higher rate of technical success and lower mortality rates than OSA, even with greater number of patients with diabetes and more severe cases of ischemia and infection. However, prospective studies comparing both techniques are needed for further evidence.

Diabetic foot infections with osteomyelitis: efficacy of combined surgical and medical treatment

Diabetic foot infections are a high risk for lower extremity amputation in patients with dense peripheral neuropathy and/or peripheral vascular disease. When they present with concomitant osteomyelitis, it poses a great challenge to the surgical and medical teams with continuing debates regarding the treatment strategy. A cohort prospective study conducted between October 2005 and October 2010 included 330 diabetic patients with osteomyelitis mainly involving the forefoot (study group) and 1,808 patients without foot osteomyelitis (control group). Diagnosis of osteomyelitis was based on probing to bone test with bone cultures for microbiological studies and/or repeated plain radiographic findings. Surgical treatment included debridement, sequestrectomy, resections of metatarsal and digital bones, or toe amputation. Antibiotics were started as empirical and modified according to the final culture and sensitivities for all patients. Patients were followed for at least 1 year after wound healing. The mean age of the study group was 56.7 years (SD = 11.4) compared to the control group of 56.3 years (SD = 12.1), while the male to female ratio was 3:1. At initial presentation, 82.1% (n=271) of the study group had an ulcer penetrating the bone or joint level. The most common pathogens were Staphylococcus aureus (33.3%), Pseudomonas aeruginosa (32.2%), and Escherichia coli (22.2%) with an almost similar pattern in the control group. In the study group, wound healing occurred in less than 6 months in 73% of patients compared to 89.9% in the control group. In the study group, 52 patients (15.8%) had a major lower extremity amputation versus 61 in the control group (3.4%) (P=0.001). During the postoperative follow-up visits, 12.1% of patients in each group developed wound recurrence. In conclusion, combined surgical and medical treatment for diabetic foot osteomyelitis can achieve acceptable limb salvage rate and also reduce the duration of time to healing along with the duration of antibiotic treatment and wound recurrence rate.

Seminar Review: A Review of the Basis of Surgical Treatment of Diabetic Foot Infections

Infection is an extremely challenging complication of foot ulcers in patients with diabetes. Surgery as part of a multidisciplinary approach is key in the management of many types of diabetic foot infections (DFIs). Unfortunately, the surgical treatment of DFIs is based more on clinical judgment and less on structured evidence, which leaves unresolved doubts. The clinical presentation of DFIs is varied. This review examines the basis of nonvascular surgical treatment of DFIs, emphasizing the importance of the anatomic concepts of the foot, the variety of its clinical presentations, and the concepts of timing surgery. Recent evidence and case reports based on the author’s experience are presented in 2 parts. The first part examines clinical presentation of infections, whereas the second part deals with imaging, foot anatomy, and some case reports.

Salvage of Charcot foot neuropathy superimposed with osteomyelitis: a case report

The risk of amputation is dramatically increased in diabetic patients with osteomyelitis of the foot complicated by Charcot neuroarthropathy. Antibiotic-impregnated cement beads have been widely reported in the treatment of deep soft tissue and bone infections. This case report demonstrates that this approach can also aid the management of infected, unstable diabetic Charcot foot.

Percutaneous flexor tenotomy for treatment of neuropathic toe ulceration secondary to toe contracture in persons with diabetes: a systematic review

Percutaneous flexor tenotomy has been proposed for treatment of neuropathic toe ulcerations secondary to toe contracture in persons with diabetes who have failed ongoing local wound care measures due to the perceived safety and efficacy. Because this patient population comprises a substantial proportion of the authors' practice, we undertook a systematic review of electronic databases and other relevant sources to identify material relating to the use of percutaneous flexor tenotomy for the treatment of neuropathic toe ulcerations secondary to toe contracture deformities in persons with diabetes. Information from peer-reviewed journals, as well as that from non-peer-reviewed publications, abstracts and posters, textbooks, and unpublished works, was considered. In an effort to procure the highest-quality studies available, studies were eligible for inclusion only if they involved consecutively enrolled patients undergoing the same percutaneous surgical treatment, evaluated patients at a mean follow-up of > or =12 months' duration, and included details of complications. Two studies were identified that met the inclusion criteria, both of which were retrospective case series of relatively poor methodological quality. Rather than providing strong evidence for or against the use of percutaneous flexor tenotomy for the treatment of neuropathic toe ulceration secondary to toe contracture in persons with diabetes, the results of this systematic review make clear the need for methodologically sound prospective cohort studies and randomized controlled trials that focus on the use of this form of surgical intervention.

LEVEL OF EVIDENCE

1.

A 1-piece shape-metal nitinol intramedullary internal fixation device for arthrodesis of the proximal interphalangeal joint in neuropathic patients with diabetes

A common complication associated with diabetes is the development of a rigid structural lesser toe contracture, which, when combined with peripheral sensory neuropathy, can lead to ulceration, infection, and amputation. Surgical correction of lesser toe contractures in persons with diabetes has been advocated to decrease the potential for ulceration and amputation. Lesser toe proximal interphalangeal joint arthrodesis employing myriad joint preparation and fixation methods is commonly performed to correct a rigid structural toe contracture. The author performed a retrospective, observational, cohort study involving 10 patients (30 toes) with diabetes, dense peripheral neuropathy, and rigid structural toe contracture treated with a 1-piece shape-memory Nitinol intramedullary internal fixation device for arthrodesis of the proximal interphalangeal joint. Successful fusion was achieved in 28 of 30 toes (93%), with a stable nonunion achieved in the remainder. Complications that arose occurred early in the author's experience with this implant and consisted of secondary contracture of the distal interphalangeal joint (23%), displaced fixation (13%), and malunion (7%). No patient developed ulceration, and no additional surgery has been required to date. When properly performed, the use of this implant for arthrodesis of the proximal interphalangeal joint in neuropathic patients with diabetes appears safe and reliable.

A Case Report of a Double Advancement Flap Closure Combined With an Ilizarov Technique for the Chronic Plantar Forefoot Ulceration

Soft tissue closure of defects on the plantar surface of the foot continues to be a challenge for the reconstructive surgeon secondarily to the limited number of surgical options and often difficulty of replacing durable and similar soft tissue coverage. Primary closure and skin grafting may not be suitable for the weight-bearing surfaces of the plantar forefoot area, and closure may then be obtained by other means of plastic surgery techniques.

Surgical management of diabetic foot infections and amputations

The incidence of diabetes with severe foot infections (eg, necrotizing fasciitis, gas gangrene, ascending cellulitis, infection with systemic toxicity or metabolic instability) has risen significantly during the past decade. Foot infections are a major cause of hospitalization and subsequent lower extremity amputation among patients with diabetes mellitus who have a history of a preexisting ulceration. Surgical management often is required to address severe diabetic foot infections because they can be limb- or life-threatening. Critical limb ischemia, neuropathy, and an immunocompromised host, which often are associated with diabetic foot infections, complicate treatment and are associated with a poorer prognosis.

Plastic surgery reconstruction of the diabetic foot

Soft tissue reconstruction of the diabetic foot is a challenge for the perioperative team. Primary closure may not be an option and secondary healing may not be reliable. Therefore, surgery is vital and should be coordinated among a well-functioning multidisciplinary team that specializes in caring for patients with diabetes mellitus. Team members must have expertise in reconstructive surgery to ensure adequate wound healing. This article emphasizes the appropriate timing and staging of surgery, discusses the most common plastic surgery techniques, and underscores the importance of a team approach in the management of diabetic foot wounds.

Closure of major diabetic foot wounds and defects with external fixation

Amputation may become unavoidable in certain cases of severe ischemia, infection, or lower extremity ulcerations. When limb salvage procedures are indicated and available in diabetic patients, they will strongly support patient quality of life and prevent further complications when patients are educated appropriately. The authors describe their technique for limb salvage procedures based on a combination of an MRI-guided debridement of necrotic tissues, application of an antibiotic-impregnated bone cement, and closure of the soft tissue and bone defects with the use of an external fixation device.

Addressing psychosocial aspects of care for patients with diabetes undergoing limb salvage surgery

Surgeons provide a key role in improving the life of patients with diabetes-related foot complications who undergo limb salvage surgery as an alternative to amputation. An integrated multidisciplinary approach is essential to improve the emotional well-being of these patients to avoid potential complications that may prolong their convalescence and further degrade their psychosocial welfare. The authors attempt to increase awareness of critical preoperative risk factors that should be obtained by a thorough comprehensive psychosocial evaluation. In addition, this article discusses how to interact with the patient and his or her family throughout the perioperative period, assisting the patient in managing psychosocially and increasing the likelihood of an optimal outcome.

Advanced plastic surgery techniques for soft tissue coverage of the diabetic foot

Obtaining stable, durable, and functional wound closure of a diabetic foot wound or open pedal amputation through plastic surgical techniques is essential to limit the potential for repeated ulceration, infection, and "supra-pedal" amputation. Myriad conservative and surgical techniques can be used to obtain wound closure. The authors discuss their approach and present operative pearls for their most commonly employed plastic surgical techniques to provide adequate soft tissue coverage of diabetic foot wounds. Emphasis is placed on the techniques necessary to perform these procedures and the surgical thought process involved in closing diabetic foot wounds.

Diabetic Foot Disease

OBJECTIVE

To review the spectrum of foot problems in patients with diabetes and the underlying etiologic factors.

METHODS

In this review, the term "diabetic foot disease" (DFD) will be used (previously referred to as simply "diabetic foot"). The relevant anatomy of the foot is discussed, the clinical evaluation and severity of DFD are outlined, and the role of both systemic control and local measures in the management of DFD is addressed.

RESULTS

DFD is linked with a wide variety of etiologic associations, pathologic forms, and clinical severity. The causes of DFD include such factors as diabetic neuropathy, vascular insufficiency, and the presence of underlying bone deformity. The pathologic forms range from superficial skin lesions, soft tissue infections, joint swellings, and deformities to frank necrosis and gangrene. The clinical severity ranges from mild, self-resolving disease to fulminant, rapidly progressive disease that usually eventuates in amputation. The heterogeneity of patients whose illness is grouped collectively under the diagnosis of DFD has contributed to the persisting confusion and controversy regarding the optimal classification system for diabetes-related foot problems and their appropriate management.

CONCLUSION

Optimal management of DFD involves a multimodality approach directed at regular foot care, blood glucose control, and early recognition of foot problems. Appropriate surgical management, administration of systemic antibiotics, and off-loading techniques are necessary to prevent the progression of DFD.