Evaluation was done of 235 patients who had had 273 primary amputations
for gangrene. Measurements of local skin-perfusion pressure or systolic
blood pressure were made in 222 limbs (188 patients). For the other
fifty-one limbs, for which no measurements of pressure were available, the
surgeon elected to perform an above-the-knee amputation in nine of
seventeen diabetic limbs and a below-the-knee amputation in eight. An
above-the-knee amputation was selected by the surgeon for thirty-two of
thirty-four non-diabetic limbs and a below-the-knee amputation, for two for
which no measurements of pressure were available. Local skin-perfusion
pressure was measured distal to the knee before amputation, using a
standardized photoelectric technique in 203 limbs and systolic
blood-pressure measurements in nineteen. Skin-perfusion pressure was also
measured above the knee in seventy-six of the 222 limbs in which a pressure
was determined below the knee. These measurements were made available to
the surgeon for use as an adjuvant guide to clinical assessment in
selecting the appropriate level of amputation. Seventy-four patients
(ninety-two amputations) had diabetes and 114 patients (130 amputations)
did not. The limbs of the diabetic patients had a significantly higher
skin-perfusion pressure at the below-the-knee level (p less than 0.001)
than did those of the non-diabetic patients. The ratios of below-the-knee
to above-the-knee amputations for the diabetic and non-diabetic patients
were 3.8 to one and 1.3 to one (p less than 0.001).(ABSTRACT TRUNCATED AT
250 WORDS)