The aim of this research is to study the capillary flow in the skin of the forearm in the process of distractional osteosynthesis in patients with congenital dysgenesis of the upper limb. 28 patients in the age of 4-18 years old were examined. The study of tissue blood flow in the skin of lengthened and intact forearms with LDF allows to reveal its definite dynamics testifying the absence of ischemic disorders in the skin of the lengthened forearm. The transosseous distractional osteosynthesis, used in the Center, provides favorable conditions for micro-flow processes, which do not interfere regulating mechanisms in the system of tissue blood circulation. An ischemic functional test proves lower reactivity of the micro-circular vascular bed in the skin of the injured forearm than of the intact segment.