In this study the authors present a method of conversion of external fixations to closed intramedullary ones in the treatment of complicated diaphyseal fractures of the calf and femur. According to the conditions, the fixation is secured by a pin. The above mentioned procedure is advantageous especially in cases of patients with open fractures, in patients with polytraumas as well as in patients with a threatening or with a present compartment syndrome. Treatment of the above fractures is not always simple and represents a serious problem in everyday traumatological practice. Treatment of fractures using the above procedure has very good results with a minimum of complications. Although, nowadays, the skeletal defect can be solved and therefore the bearing capacity of the extremity be renewed, damages to the muscles are often irreparable and cause a permanent invalidity.

        Key words: conversion – external fixation – diaphysis – secured intramedullary pins