Cylindrical biodegradable rods of self-reinforced polyglycolide were constructed for internal fixation of fractures in cancellous bone. The self-reinforced texture was achieved by embedding polyglycolide fibres in a polyglycolide matrix. In a prospective clinical study, 62 patients with displaced bimalleolar fractures were managed by open reduction and internal fixation using these rods. The results were assessed between 1.1 and 3.4 years from implantation. One wound infection occurred (1.6%). Five patients (8.1%) developed a sterile accumulation of fluid at the site of operation which required drainage: the final outcome was not affected. Minor displacement of the fracture (1-2 mm) occurred in nine patients (14.5%) but did not need further operation. The functional result was excellent in 39 patients (63%). This was considered acceptable given the severity of the fractures. Consequently, at our hospital, when a displaced malleolar fracture needs internal fixation biodegradable rods are now the treatment of choice. The psychological and financial advantages of avoiding implant removal are considerable.