Lower Limb Amputation Rates in Patients With Diabetes and an Infected Foot Ulcer: A Prospective Observational Study

Lower extremity amputation is a serious complication of diabetes mellitus and occurs most commonly in persons who have a foot ulcer.

To examine variables that affect the rate of lower extremity amputation in patients with diabetes and infected foot ulcers.

A prospective observational study was performed including all consecutive patients who were 18 to 65 years, had a diagnosis of diabetes, and a foot ulcer showing clinical signs of infection. Patients were followed for 6 months or until ulcer healing, minor, or major amputation. A total of 81 persons were enrolled. Demographic variables were obtained, and clinical assessments, blood tests, and radiological investigations were performed. Ulcers were categorized using the Perfusion, Extent, Depth, Infection and Sensation classification system. Differences between variables and outcomes were assessed using the Wilcoxon test, Fisher's exact test, Chi-square test, and t-test.

Mean patient age was 54.58 ± 9.04 years, and the majority (61, 75%) were male. After 6 months, 33 (41%) were healed, 2 patients died, and 17 (21%) underwent major and 24 (30%) minor amputations. Major amputation rates were significantly higher in patients with a high Perfusion, Extent, Depth, Infection and Sensation score (6.92 ± 1.36; P = .005), elevated HbA1c (%) (9.43 ± 2.19; P = .049), presence of growth on wound culture (41 [64.1%]; P = .016), culture sensitivity to beta lactam (20 [31.2%]; P = .012), and presence of peripheral arterial disease seen on arterial Doppler ultrasound (P < .001). Minor amputation rates were higher in men (P = .02) and in the presence of peripheral arterial disease (P = .01).

The presence of the above factors in persons with diabetes and foot ulcer with clinical signs of infection should alert the clinician to the need for focused and individualized treatment to attempt to prevent amputation.