38. The Syme's amputation provides an end-bearing stump that in many circumstances allows ambulation without a prosthesis over short distances. It is an excellent amputation for children, in whom it preserves the physes at the distal end of the tibia and fibula (26). The Syme's amputation works well for tumors and trauma, assuming that the heel flap has been spared from the trauma. In the past, it has had a high failure rate in ischemic limbs because of failure of wound healing. Today, the success of amputation at this level has increased because local tissue perfusion is preoperatively determined with Doppler ultrasound measurement of blood pressures, with radioactive 133 Xe clearance tests, and with transcutaneous measurement of oxygenation.