Factors affecting the results of below knee amputation in patients with and without diabetes

During a five year period, 113 below knee amputations were performed upon 100 patients. Multiple factors were examined for the effects on wound complication and reamputation rates. Healing without reamputation occurred in 91.9 per cent of those in the diabetic group and in 76.5 per cent of those in the nondiabetic group, p less than 0.05. Cellulitis of the foot did not significantly affect healing below the knee in patients with diabetes, 82.5 per cent with cellulitis versus 87.5 per cent without cellulitis, p greater than 0.05, but did affect healing in those in the nondiabetic group, 81.8 per cent success versus 66.7 per cent, p less than 0.05, and affected their minor wound complication rate, 50.0 per cent with cellulitis versus 26.5 per cent without cellulitis. Absence of femoral pulses uniformly predicted a nonhealing below the knee amputation in patients with cellulitis, whereas in patients without cellulitis, healing occurred in 85 per cent. Hemoglobin levels were inversely proportional to success rates only in patients with diabetes and cellulitis, 10.54 +/- 1.68 versus 12.85 +/- 2.30 grams per deciliter for failures, p = 0.016. Elevated white blood counts were predictive of failure to heal below the knee amputations only in those in the nondiabetic group without cellulitis, 10,110 +/- 3,200 cells per millimeter3 for success versus 13,750 +/- 3,300 cells per millimeter3 for failures, p = 0.018. Use of wound drains correlated with a 55.0 per cent wound complication rate versus 16.1 per cent when drains were not used. Wound complications were minimized when amputations were closed with subcuticular suture and skin tapes.