title: Optimization of intramedullary nailing by numerical simulation of fracture healing.
abstract: Due to the annular gap between intramedullary (IM) nails and the endosteal surface, high interfragmentary movement can occur under loading. This could prolong the healing time, particularly for thin IM nails that are often used for unreamed IM nailing. The aims of our study were to determine the influence of the nail diameter on the healing time of human tibial shaft fractures and to investigate whether the healing time could be shortened by increasing the stiffness of the implant material. Therefore, a corroborated numerical model for simulating the fracture healing process in humans was used to simulate the healing process of human tibial fractures treated with IM nails. The calculated healing time (up to 71 weeks) was longest for transverse fractures treated with thin IM nails made of titanium. That the healing time was disproportionately long depended on the nail diameter, and could be greatly reduced by using a thicker nail or using steel instead of titanium. To avoid a prolonged healing time, the nail should be thick, and the annular gap should be as narrow as possible. Alternatively, using steel instead of titanium may also help to avoid a prolonged healing time.
authors: Institute of Orthopaedic Research and Biomechanics, Center of Musculoskeletal Research, Ulm University, Helmholtzstrasse 14, 89081 Ulm, Germany. timwehner@web.de
authors: Tim
authors: T
authors: Wehner
authors: Lutz
authors: L
authors: Claes
authors: Anita
authors: A
authors: Ignatius
authors: Ulrich
authors: U
authors: Simon
mesh_terms: D000465:Algorithms; D001858:Bone Nails / Q000592:standards*; D003198:Computer Simulation; D017102:Fracture Healing / Q000502:physiology*; D017143:Fuzzy Logic; D006801:Humans; D008954:Models, Biological; D019637:Orthopedic Procedures / Q000295:instrumentation / Q000379:methods / Q000592:standards; D013232:Steel; D013978:Tibial Fractures / Q000503:physiopathology* / Q000601:surgery*; D014025:Titanium
chemical_list: D013232:Steel; D014025:Titanium