Revision of below-knee amputation stumps to a higher level in patients with peripheral vascular disease

Abstract

Objective

To evaluate clinical and anatomical factors associated with failure of below-knee amputation (BKA) resulting in revision to a higher level amputation, with the aim of identifying predictors of stump healing and reducing the need for reoperation.

Methods

This retrospective single-center study included all patients who underwent a BKA between April 2014 and October 2021 for peripheral vascular disease excluding other etiologies, such as burns, trauma, or malignancy. Patients were stratified into two groups based on whether revision surgery was required. Demographic characteristics, clinical indications, prior revascularization, arterial imaging, laboratory parameters, and inpatient outcomes were compared between groups. The primary outcome was the need for revision surgery. Statistical analyses were performed using Fisher's exact test for categorical variables and Mann-Whitney U test or t test for continuous variables. Significance was set at a P value of <.05.

Results

A total of 212 patients underwent BKA during the study period using long posterior flaps. Of these, 48 patients (22.6%) required revision surgery, predominantly to above-knee amputation (73%). No significant differences in age, gender, comorbidities, or smoking status were observed between groups. Indications for initial BKA were comparable; however, patients with uncontrolled infection as the primary indication had a significantly lower revision rate (15% vs 30%; P = .04). Revascularization procedures were performed in 42% of patients but were not associated with revision risk. Arterial patency was a key differentiator. Patent profunda femoris artery (PFA) and common iliac artery were significantly more prevalent in the healed group (PFA, 73% vs 35% [P < .0001]; common iliac artery, 84% vs 58% [P = .0003]). A diseased or occluded PFA was significantly more common in patients requiring revision. Unexpectedly, superficial femoral artery occlusion was more common in the healed group (27% vs 8%; P = .006), suggesting collateral-dependent perfusion. Preoperative blood parameters did not correlate with healing. Length of hospital stay was significantly longer in the revision group (31 days vs 22 days; P = .0017).

Conclusions

Approximately one in four patients undergoing BKA required revision. Patency of the PFA emerged as the strongest predictor of stump healing, highlighting the importance of preoperative vascular assessment. Consideration should be given to performing profundoplasty before BKA in cases with compromised profunda flow to improve outcomes and reduce the need for higher-level amputations.