Predictors for Amputation in Patients with Diabetic Foot Wound

SLR - March 2019 - Andrew Olson

Reference: Kim SY1, Kim TH1, Choi JY1, Kwon YJ1, Choi DH1, Kim KC2, Kim MJ3, Hwang HK3, Lee KB1. Predictors for Amputation in Patients with Diabetic Foot Wound. Vasc Specialist Int. 2018 Dec. 31. 34(4):109–116.

Scientific Literature Review

Reviewed By: Andrew Olson, DPM
Residency Program: New York Presbyterian/Queens, Flushing, NY

Podiatric Relevance: This article delves into risk factors that patients with a diabetic foot ulcer have that increase the likelihood of amputation. This includes localized factors (such as grade of ulcer) and systemic factors (CHF, PAD, dementia, etc.). These risk factors should be evaluated by both the podiatric and vascular surgeon to help guide the treatment plan and develop a prognosis in regards to limb salvage.  

Methods: This is a retrospective study in which a total of 141 patients with a diabetic fool ulcer were enrolled, all who underwent CTA to assess for peripheral arterial disease. All wounds were then classified into the Wagner classification system, and each wound underwent debridement and/or aggressive wound care. Each patient was started on empiric IV antibiotics, which were then tailored after obtaining cultures. Each CTA was reviewed by two radiologists, and if PAD was diagnosed, the patient was placed into one of three groups based on the anatomic location of the disease.  Revascularization procedures were performed on patients if deemed appropriate. Demographic features and potential risk factors were investigated to predict major amputation in these patients, including age, gender, HTN, CAD, CKD, hemodialysis, HbA1c, DM medication, osteomyelitis, smoking status and dementia.  

Results: Major amputations were performed in 26.2 percent of patients. Major amputation rates in patients with diabetic foot gangrene was 47.1 percent, compared to 6.8 percent in those without gangrene. The major risk factors found to be statistically significant in regards to nonmajor and major amputation were Wagner classification grade, CAD, CHF, leukocytosis, dementia and PAD.  Furthermore, 53.9 percent of these patients were diagnosed with PAD, and 38.2 percent of those patients underwent major amputation. Of those with a diabetic foot ulcer without PAD (73 total patients), 38.4 percent underwent nonmajor amputation and 6.2 percent underwent major amputation. Statistically significant risk factors between these two groups were age and presence of OM.

Conclusion: Studies show that DM increase the risk of major nontraumatic amputation 20 fold. In these patients, other comorbidities are predictors for major amputation. In patients with a diabetic foot wound and PAD, a higher grade Wagner ulcer and leukocytosis were significant risk factors for major amputation. In this study, the overall rate of major amputation in patients with a diabetic foot wound was 26.4 percent. The significant risk factors for major amputation were Wagner classification grade, CHF, leukocytosis, dementia and PAD. Knowing these risk factors allows providers to better inform patients about the likelihood of success for limb salvage.