Factors Associated With Lower-Extremity Amputation in Patients With Diabetic Foot Ulcers

From Northwell Health System, Lake Success, NY.

Abstract

• Objective: To explore factors associated with lower-extremity amputation (LEA) in patients with diabetic foot ulcers using data from the Online Wound Electronic Medical Record Database.
• Design: Retrospective analysis of medical records.
• Setting and participants: Data from 169 individuals with previously diagnosed diabetes mellitus who received wound care for a 6-month period within a span of 2 years was analyzed. A baseline evaluation was obtained and wound(s) were treated, managed, and monitored. Treatment continued until the patient healed, required an LEA, or phased out of the study, neither healing nor undergoing an amputation. Of the 149 patients who completed the study, 38 had healed ulcers, 14 underwent amputation, and 97 neither healed nor underwent an amputation. All patients were treated under the care of vascular and/or podiatric surgeons.
• Measurements: Variables included wound status (healed, amputated, and unhealed/non-amputated); size of wound area; age, gender, race, and ethnicity; white blood cell (WBC) count, hemoglobin A1c (HbA1c), blood glucose, and body mass index (BMI); and presence of osteomyelitis, gangrene, and peripheral vascular disease.
• Results: As compared to the healed and unhealed/non-amputated group, the group of patients who underwent LEA was older and had higher percentages of males, Hispanics, and African Americans; had a higher WBC count, larger wound area, and higher rates of wound infection, osteomyelitis, and neuropathy; and had lower average values of HbA1c, blood glucose, and BMI and a lower rate of peripheral vascular disease.
• Conclusion: The association between HbA1c and LEA highlights a window of relative safety among an at-risk population. By identifying and focusing on factors associated with LEA, health care professionals may be able to decrease the prevalence of LEA in patients with diabetes.

Keywords: diabetic foot ulcer; lower-extremity amputation; risk factors; HbA1c.

An estimated 30.3 million people, or 9.4% of the US population, has diabetes. In 2014, approximately 108,000 amputations were performed on adults with diagnosed diabetes.¹ Furthermore, patients with diabetes have a 10-fold increased risk for lower-extremity amputation (LEA), as compared with patients without diabetes.² The frequency of amputations in the diabetic population is a public health crisis.

Amputation has significant, life-altering consequences. Patients who undergo LEA often face debilitation in their daily activities and must undergo intense rehabilitation to learn basic tasks. Amputations can also impact individuals’ psychological well-being as they come to terms with their altered body and may face challenges in self-perception, confidence, self-esteem, work life, and relationships. In addition, the mortality rate for patients with diabetes 5 years after undergoing LEA is 30%.² However, public health studies estimate that more than half of LEAs in patients with diabetes are preventable.³

Although studies have explored the relationship between diabetes and LEA, few have sought to identify factors directly correlated with wound care. In the United States, patients with diabetic ulcerations are typically treated in wound care facilities; however, previous studies have concentrated on the conditions that lead to the formation of an ulcer or amputation, viewing amputation and ulcer as 2 separate entities. Our study took into account systemic variables, patient demographics, and specific wound characteristics to explore factors associated with LEA in a high-risk group of patients with diabetes. This study was designed to assess ailments that are prevalent in patients who require a LEA.