Prospective Evaluation of the Society for Vascular Surgery (SVS) Wound, Ischemia, and Foot Infection (WiFi) Classification for Predicting Amputation Risk in Diabetic Foot Ulcers at a South Indian Tertiary Care Center

Background Diabetic foot ulcers (DFUs) are a major cause of limb loss. Early identification of high-risk cases is essential, especially in settings where patients often present late and specialized vascular care is limited. The Society for Vascular Surgery (SVS) Wound, Ischemia, and foot Infection (WIfI) classification - which grades severity of the wound, degree of ischemia, and extent of infection - offers a structured approach to assess limb threat and estimate amputation risk. This study aimed to prospectively evaluate the accuracy of the SVS WIfI classification system in predicting lower limb amputation risk among patients with DFUs at a tertiary care center in South India. Methodology In this prospective observational study, 50 adult patients presenting with DFUs were evaluated and categorized using the SVS WIfI classification. Patients were stratified into two groups: Group 1 (Stages 1-3) and Group 2 (Stage 4). Demographic, clinical, and laboratory data were collected. Amputation outcomes were assessed, and multivariate logistic regression was performed to identify independent predictors of amputation. Although the estimated sample size was 163, only 50 patients fulfilled eligibility criteria within the study period. Results Among the 50 participants, 32 (64%) were classified as WIfI Stage 4. The amputation rate was significantly higher in Group 2 compared with Group 1 (62.1% vs. 6.7%, p < 0.001). Multivariate analysis demonstrated that WIfI Stage 4 was the strongest independent predictor of amputation. Other significant predictors included symptom duration greater than 48 hours, leukocytosis, elevated C-reactive protein (CRP), and poor glycemic control (HbA1c > 8%). Conclusion The SVS WIfI classification is a robust and reliable tool for risk stratification in patients with DFUs. Incorporating WIfI staging into routine clinical practice can facilitate timely interventions and help reduce the burden of limb loss, especially in resource-constrained healthcare settings. A relatively small sample size is a limitation; however, the findings reinforce the system's clinical value and encourage larger-scale validation.