vertical expandable prosthetic titanium rib vertical expandable prosthetic titanium rib vertical expandable prosthetic titanium ribs (veptr) is a product of synthes for the treatment of childhood deformities of the thorax. it is a special form of a lengthenable rod ("growing rod"). an alternative system is the uss pediatric for older children, also from synthes. thoracic scoliosis due to diastematomyelia and myelomeningocele (mmc) in a 10-year-old boy the instrument is used to dilate a too small or too narrow rib thorax in severe thoracic deformity. it consists of a telescopic "titanium rib" in curved form with several holes in a row for fixing in the desired length. a prolongation can be carried out after 6 months. the fixation takes place between two ribs or between a rib and the iliac crest. this results in an indirect erection of the deformed spine, resulting in an increase in the volume of the thoracic cavity along with the lung.