Chapter 24: Surgical Management of the Neuropathic Foot

Epidemiology of the Neuropathic Foot

In the United States, 1.3 million new cases of diabetes are diagnosed annually in people aged 20 and over.¹ The prevalence of diabetes in the United States for all ages is 6.3%. In the Medicare population (aged 65 and over), persons with diabetes incur 1.7 times the health-care expenditures of those without diabetes. Individuals with diabetes who are enrolled in private health insurance through their employers incur higher mean annual costs; $132 billion was spent in 2002, with direct medical expenditures of $91.8 billion and indirect costs of $23.2 billion. Inpatient days accounted for 43.9% of direct medical expenditures. Patients in this group incurred costs that were approximately 2.4 times higher than a similar group without diabetes ($7,778 versus $3,367).²

Neuropathic foot ulcers are a serious complication of diabetes.³ Of the over 20 million patients in the United States with this disease, 15% will develop foot ulcers, and 6% will be hospitalized with this condition.^4,5 Vascular disease is 20 times more prevalent in this group, and impaired blood flow impedes healing.⁶ Functional microangiopathy leads to many sequelae, including neuropathy; this condition is the most important factor leading to ulceration and is present in more than 80% of patients with diabetes and ulcerative lesions.⁷ Williams et al proved that neuropathy and microvascular complications increased the annual cost of care by 70%. Among the millions of patients in the United States with diabetes, there are an estimated 1200 amputations performed each week; 84% of these surgeries are preceded by a foot ulcer.^8,9 The direct costs of lower-extremity amputations in patients with diabetes range between $20,000 and $60,000¹⁰; however, when expenditures relating to rehabilitation and failed vascular procedures are coupled with the indirect cost of lost productivity, these amounts exceed these cited costs.¹¹

In a retrospective review of 186 amputations performed on 146 patients with diabetes, Van Damme et al determined that an aggressive control of infection and distal revascularization of calf or foot arteries,¹² when feasible, could improve the results of foot surgery in this patient group. Additionally, the poor functional recovery after major amputation (only 63% had autonomic gait with limb prosthesis) argued for foot-sparing surgery whenever possible. A retrospective study by Apelqvist et al involving treatment of patients with diabetes who had foot ulcers indicated the potential cost savings of preventative and multidisciplinary foot care.¹³

Persons with diabetes often develop a triad of neuropathy, including the sensory, autonomic, and motor systems. Insensate feet coupled with dry, ...