title: Intramedullary nailing of the cortical bone osteotomies in rabbits with self-reinforced poly-L-lactide rods manufactured by the fibrillation method.
abstract: Right femoral, cortical bone osteotomies of 42 rabbits were fixed with fibrillated, self-reinforced (SR) poly-L-lactide (PLLA) rods, 4.5 mm in diameter. Follow-up times were from 3 to 48 wk. None of the rods broke during this period. There was one non-union at three weeks and one non-union at 12 weeks. Radiographic, histologic, microradiographic and oxytetracyclic fluorescence studies showed normal healing. Shear load carrying capacity of the osteotomy plane was measured from 30 bone samples; the shear force at breaking increased during the follow-up time to 450 N, while the mean shear force of intact, left-side control femurs was 440 N. Before shear tests of the bones, the SR-PLLA rods were taken away from the medullary cavities of the femurs. The rods were also tested mechanically. About 25% of the initial 136 MPa shear-strength of the rods was left after 24 wk. The results show that fibrillated SR-PLLA rods are strong enough to be used in intramedullary nailing of femoral cortical bone osteotomies in rabbits.
authors: Department of Orthopaedics and Traumatology, Helsinki University Central Hospital, Finland.
authors: M J
authors: MJ
authors: Manninen
authors: T
authors: T
authors: Pohjonen
mesh_terms: D000818:Animals; D001858:Bone Nails; D005264:Femoral Fractures / Q000601:surgery*; D005269:Femur / Q000000981:diagnostic imaging; D005594:Fracture Fixation, Intramedullary; D017102:Fracture Healing; D007773:Lactates; D019344:Lactic Acid; D008856:Microscopy, Fluorescence; D010027:Osteotomy; D011091:Polyesters; D011108:Polymers; D019736:Prostheses and Implants; D011817:Rabbits; D011859:Radiography; D013314:Stress, Mechanical
chemical_list: D007773:Lactates; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide)