Abstract
Plaster cast immobilization treatment of isolated ulnar fractures is thought by many to be associated with a high incidence of nonunion (Grace and Witmer 1980; Brakenbury et al. 1981). Watsonjones (1934), while claiming to be in favor of nonsurgical treatment of fractures in general, stated that ulnar fractures were best treated by means of plate fixation as he believed that the above-the-elbow cast did not sufficiently immobilize the fracture fragments. Others have attempted to explain the alleged high nonunion rate on the grounds that its superficial placement under the skin deprives the injured bone of sufficient blood supply. Others suspect that its predominantly cortical composition predisposes to pseudoarthrosis or that the intact radius keeps the ulnar fragments distracted. For these and perhaps others reasons, internal plate osteosynthesis of isolated ulnar fractures is currently a widely and popularly accepted method of treatment.