A novel shape memory plate osteosynthesis for noninvasive modulation of fixation stiffness in a rabbit tibia osteotomy model
Creators: name: Müller, Christian W.
name: Pfeifer, Ronny
name: Meier, Karen
name: Decker, Sebastian
name: Reifenrath, Janin
name: Gösling, Thomas
name: Wesling, Volker
name: Krettek, Christian
name: Hurschler, Christof
name: Krämer, Manuel
Publisher: name: New York, NY : Hindawi Publishing Corporation
Year: 2015
Subjects: subject: nickel
subject: titanium
subject: biomaterial
subject: titanium nickelide
subject: adult
subject: animal experiment
subject: animal model
subject: Article
subject: body temperature
subject: bone mass
subject: bone plate
subject: controlled study
subject: fracture healing
subject: in vitro study
subject: male
subject: nickel titanium shape memory alloy implant
subject: nonhuman
subject: osteotomy
subject: plate fixation
subject: rabbit model
subject: radiography
subject: randomized controlled trial
subject: rigidity
subject: shape memory effect
subject: temperature measurement
subject: tibia osteotomy
subject: wound closure
subject: Young modulus
subject: animal
subject: chemistry
subject: devices
subject: diagnostic imaging
subject: disease model
subject: osteosynthesis
subject: procedures
subject: rabbit
subject: surgery
subject: tibia
subject: Animalia
subject: Oryctolagus cuniculus
subject: Animals
subject: Biocompatible Materials
subject: Bone Plates
subject: Disease Models, Animal
subject: Fracture Fixation, Internal
subject: Male
subject: Nickel
subject: Osteotomy
subject: Rabbits
subject: Radiography
subject: Tibia
subject: Titanium
subject: Dewey Decimal Classification::600 | Technik::610 | Medizin, Gesundheit
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: Nickel-titanium shape memory alloy (NiTi-SMA) implants might allow modulating fracture healing, changing their stiffness through alteration of both elastic modulus and cross-sectional shape by employing the shape memory effect (SME). Hypotheses: a novel NiTi-SMA plate stabilizes tibia osteotomies in rabbits. After noninvasive electromagnetic induction heating the alloy exhibits the SME and the plate changes towards higher stiffness (inverse dynamization) resulting in increased fixation stiffness and equal or better bony healing. In 14 rabbits, 1.0 mm tibia osteotomies were fixed with our experimental plate. Animals were randomised for control or induction heating at three weeks postoperatively. Repetitive X-ray imaging and in vivo measurements of bending stiffness were performed. After sacrifice at 8 weeks, macroscopic evaluation, μCT, and post mortem bending tests of the tibiae were carried out. One death and one early implant dislocation occurred. Following electromagnetic induction heating, radiographic and macroscopic changes of the implant proved successful SME activation. All osteotomies healed. In the treatment group, bending stiffness increased over time. Differences between groups were not significant. In conclusion, we demonstrated successful healing of rabbit tibia osteotomies using our novel NiTi-SMA plate. We demonstrated shape-changing SME in-vivo through transcutaneous electromagnetic induction heating. Thus, future orthopaedic implants could be modified without additional surgery.