The present invention relates to a medical fixation apparatus for a lesion. According to an embodiment, a medical cast comprises: an expansion band having a predetermined length; a pair of elastic fibers which are coupled to opposite widthwise edges of the expansion band, are coated with a water-curable synthetic resin, and can surround a body part; and a plurality of coupling units, which have a flat shape and, when the pair of elastic fibers surround a body part, are arranged at a predetermined interval along an edge at which the pair of elastic fibers face each other to connect the pair of elastic fibers.