Measurement of deep muscle temperature in ischemic limbs

Temperature profiles extending from the deep muscle out to the surface at points above and below the knee were measured using a 22 gauge thermistor probe in the form of a hypodermic needle in 15 ischemic limbs before amputation and 3 normal limbs before and elective surgery. Of the 15 ischemic limbs studied, 8 had below-knee and 7 above-knee amputations, all of which healed without requiring revision. The mean difference between the maximum deep muscle temperature measured 15 cm above and 10 cm below the knee was 1.01 degree C in the below-knee amputation group and 1.06 degree C in the normal group. The temperature difference in the below-knee and above-knee groups was statistically significant (p less than 0.027). This relatively simple and easily performed technique of measuring deep muscle temperature appears to be a useful adjunct in choosing the amputation level.