Shape Memory Implants

Basic Properties.- Bioperformance of Shape-Memory Alloys.- 1 Introduction.- 2 Medical Applications.- 2.1 Orthopedic Surgery.- 2.2 Cardiovascular Surgery.- 2.3 Gastroenterologic Surgery.- 2.4 Urologic Surgery.- 2.5 Other Medical Devices.- 2.6 FDA Status of NiTi Medical Devices.- 3 Biocompatibility of NiTi Alloys.- 3.1 Nickel Issue.- 3.2 In Vitro Biocompatibility (Cell Cultures).- 3.3 In Vivo Biocompatibility of NiTi (Animal Models).- 3.3.1 Soft-Tissue Response.- 3.3.2 Vascular-Tissue Response.- 3.3.3 Bone-Tissue Response.- 3.4 Clinical Studies of NiTi Orthopedic Devices.- References.- Processing and Quality Control of Binary NiTi Shape-Memory Alloys.- 1 Introduction.- 2 Production and Processing of NiTiNOL.- 3 Thermomechanical Treatment and Functional Properties.- 4 Quality Control of NiTiNOL Semi-Finished Shapes.- 4.1 Definition of Terms.- 4.2 Measurement of Relevant Functional Properties.- 5 Conclusions.- References.- Corrosion Resistance and Biocompatibility of Passivated NiTi.- 1 Introduction.- 2 Active Corrosion Testing.- 3 Passive Corrosion Behavior.- 4 Effect of Surface Layer on Corrosion Resistance.- 5 Nickel Release and Biocompatibility.- 6 Conclusions.- References.- The High Damping Capacity of Shape-Memory Alloys.- 1 Introduction.- 2 Internal Friction Behaviour of Shape-Memory Alloys.- 2.1 Internal Friction during Martensitic Transformation.- 2.2 Internal Friction in the Martensitic Phase.- 2.2.1 Frequency.- 2.2.2 The Temperature Rate.- 2.2.3 The Amplitude.- 2.2.4 Time Dependence.- 2.2.5 Relaxation Peaks in Ni-Ti and Cu-Based Martensites.- 2.2.6 How Large is the Damping Capacity?.- 2.3 Specific Results on Ni-Ti Shape-Memory Alloys.- 2.4 Energy Loss during Pseudoelastic Loading.- 2.5 Some Remarks on the Fatigue Life of SMA Devices.- 3 Conclusions.- References.- Physical and Biochemical Principles of the Application of TiNi-Based Alloys as Shape-Memory Implants.- 1 Introduction.- 2 Shape-Memory Effect and Pseudoelasticity in TiNi-Based Alloys.- 2.1 Role of the Chemical Composition.- 2.2 Role of the Phase Composition and the Thermomechanical Treatment.- 2.3 Pseudoelastic Behavior of TiNi-Based Alloys.- 2.3.1 Shape-Memory Effect.- 2.3.2 Ail-Round Shape-Memory Effects.- 2.3.3 Superelasticity.- 3 Corrosion Properties and Electrochemical Behavior of TiNi-Based Alloys.- References.- Porous NiTi as a Material for Bone Engineering.- 1 Introduction.- 2 Porous Biomaterials in Craniomaxillofacial Applications.- 3 NiTi Biocompatibility.- 3.1 Mechanisms of NiTi Biocompatibility.- 4 Authors’Experience with NiTi.- 5 NiTi Versus Other Biomaterials.- 5.1 Mechanical Considerations.- 5.2 Formation Considerations.- 5.3 Machining.- 5.4 Biocompatibility.- 6 Present and Future Advantages of Porous NiTi.- 7 Future Work.- 8 Conclusions.- References.- Ti-Ni-Mo Shape-Memory Alloys for Medical Applications.- 1 Introduction.- 2 Phase Transformation Behaviors of Ti-Ni-Mo Alloys.- 3 Deformation Characteristics of Ti-Ni-Mo Alloys.- 4 Shape-Memory Characteristics of Ti-Ni-Mo Alloys.- 5 Summary.- References.- Orthopaedic Applications.- Ti-Ni-Mo Shape-Memory Alloys for Medical Applications.- 1 Introduction.- 2 The Basic Principles and Requirements.- 2.1 Biocompatibility and Mechanical Properties.- 2.2 Transformation and Recovery Temperatures.- 2.3 The Recovery Force.- 3 Shape-Memory Implants in the Treatment of Transarticular Fracture.- 3.1 Compression Staples.- 3.2 Patellar Fixator Ill.- 3.3 The Shape-Memory Screw Ill.- 4 Shape-Memory Implants in the Treatment of Long-Bone Shaft Fractures.- 4.1 Shape-Memory Sawtooth-Arm Embracing Internal Fixator.- 4.2 Fork-Like Shape-Memory Intramedullar Nail and Bow-Shaped Compressive Osteo-Connector.- 5 Hand Surgery.- 5.1 Shape-Memory Compression Plate.- 5.2 Clamping Plate.- 6 Spinal Surgery.- 6.1 O-Shaped Intravertebral Artificial Joint.- 6.2 Shape-Memory Expansion Clamp.- 6.3 Shape-Memory Device Used in Scoliosis.- 7 Arthroplasty.- 7.1 Shape-Memory Double-Cup Prosthesis of Hip.- 7.2 Other Applications.- 8 Future Studies.- References.- The Surgical Correction of Scoliosis with Shape-Memory Metal.- 1 Introduction.- 1.1 Scoliosis.- 1.2 The Current Surgical Treatment of Scoliosis.- 2 Biomechanical Aspects of the Correction of Scoliosis with Shape-Memory Metal.- 2.1 The Force System in the Scoliotic Spine.- 2.2 Force-Controlled Correction of Scoliosis with Shape- Memory Metal.- 3 Biocompatibility Aspects of the Shape-Memory Metal Scoliosis-Correction Device.- 3.1 The in Vitro Biocompatibility of Shape-Memory Metal.- 3.2 Animal Experience with Shape-Memory Metal Scoliosis Correction Device.- 4 Conclusions.- References.- Shape-Memory Implants in Spinal Surgery: Long-Term Results (Experimental and Clinical Studies).- 1 TiNi Device for the Anterior Fusion of the Spine.- 1.1 Introduction.- 1.2 Material, Method and Experimental Results.- 1.3 Clinical Results.- 1.4 Complications.- 1.5 Discussion.- 1.6 Conclusion.- 2 Porous TiNi Implants.- 2.1 Introduction.- 2.2 Material, Method and Experimental Results.- 2.3 Clinical Results.- 2.4 Conclusions.- References.- The Use of a Memory-Shape Staple in Cervical Anterior Fusion (about 100 Human Implantations).- 1 Introduction.- 2 Nitinol: Properties, Biocompatibility.- 3 Device Description.- 4 Surgical Technique.- 5 Material and Methods.- 6 Results.- 7 Other Complications.- 8 Discussion.- 9 Conclusions.- References.- The Double Compressive Nickel-Titanium Shape-Memory Staple in Foot Surgery.- 1 Introduction.- 2 The Doubly Compressive Nickel-Titanium Shape-Memory Staple.- 2.1 Description.- 2.2 Working Principles.- 3 Material and Methods.- Orthodontic Applications.- Corrosion Behavior of Ni-Ti Alloys in a Physiological Saline Solution.- 1 Introduction.- 2 Anodic Corrosion Behavior of the NiTi Alloy and Other Implant Alloys.- 3 Dissolution of Ni Ions from the NiTi Alloy.- 4 Characterization of the Surface Oxide Film on a Ni-Ti Alloy.- 5 Surface Structure and Corrosion Characteristics of the NiTi Alloy.- 6 Factors Affecting the Corrosion Behavior of the NiTi Alloys.- 6.1 Effects of Alloying.- 6.2 Effects of Surface Texture.- 6.3 Effect of Contact between Dissimilar Metals.- 6.4 Effect of Amino Acids and Serum Proteins.- 7 Surface Treatments for Improving the Corrosion Resistance of the NiTi Alloy.- 8 Summary.- References.- NiTi Alloys in Orthodontics.- 1 Introduction.- 2 Conventional Wires and their Problems.- 2.1 The High-Elasticity Module.- 2.2 The High Load/Deflection Rate.- 3 NiTi Wires.- 4 Thermal NiTi Wires.- 5 Clinical Application of Thermal NiTi Wires.- 6 Properties of NiTi Alloys in Orthodontics.- 6.1 The Great Ability to Deflect (Shape Memory).- 6.2 Small Load/Deflection Ratio.- 6.3 Superelasticity.- 6.4 Memory.- 7 Advantages of NiTi Wires in Orthodontics.- 8 Temperature Treatment of Orthodontic NiTi Wires.- 9 Memory Maker.- 10 Heat-Treated Archwires and Clinical Application.- 11 NiTi-Stainless Steel Combinations.- References.- Clinical Application of Shape-Memory Alloys in Orthodontics.- 1 Introduction.- 2 History.- 3 Basic Application Principles.- 4 When are Orthodontic Wires Superelastic?.- 5 Limiting the Force.- 6 Different Force Requirements for Different Teeth.- 7 Other Superelastic Elements in Orthodontics.- 8 Conclusions and Outlook.- References.- Orthodontic application of NiTi Shape-Memory Alloy in China.- 1 Introduction.- 2 Superelastic Archwire (SE Type).- 3 Memory Archwire (RTF Type).- 4 Rocking-Chair Archwire.- 5 Superelastic Orthodontic Springs.- References.- Progressive Damage Assessment of TiNi Endodontic Files.- 1 Introduction.- 2 Materials and Methods.- 3 Results and Discussion.- 4 Conclusions.- References.- Endovascular Applications.- Effects of Surface Modification Induced by Sterilization Processes on theThrombogenicity of Nickel-Titanium Stents.- 1 Introduction.- 2 Materials.- 3 Methods.- 3.1 Animal Preparation.- 3.2 Isolation and Labeling.- 3.3 Stent Insertion.- 3.4 Extracorporeal AV Shunt.- 3.5 Auger-Electron Spectroscopy.- 3.6 Scanning Electron Microscopy.- 4 Results.- 4.1 Surface Analyses of Electropolished NiTi Stents.- 4.2 Effect of Sterilization on Thrombogenicity of Electropolished NiTi Stents.- 4.3 Effect of Blood Flow on Platelet Adhesion of Electropolished NiTi Stents in Comparison to Stainless teel.- 4.4 Morphological Analyses of the Stents Post-Perfusion.- 5 Discussion.- 6 Conclusions.- References.- X-Ray Endostenting Surgery of Vessels and Hollow Organs.- 1 X-Ray Endovascular Stent Surgery.- 2 Stenting Surgery on Bile Ducts.- 3 Stenting Surgery on Oesophagus.- 4 The Endostenting Surgery on Trachea by NiTi Spiral.- 5 The Stenting Surgery on Cervical Canal of Uterus.- References.- Device for Extravasal Correction of the Function of Vein Valves Based on Nitinol Shape Memory and Its Clinical Application.- 1 Introduction.- 2 Anatomic Examination of Main Vein Valves and Grounds for Corrector Shape Selection.- 2.1 Methods of Anatomic Examination.- 2.2 Results of Anatomic Examinations and Discussion.- 3 Shape-Memory Nitinol Extravasal Correctors.- 4 Clinical Approving and Effectivity of the Nitinol Shape-Memory Extravasal Correctors.- References.- Large-Caliber NiTi SMA Stents and Stent Grafts.- 1 Introduction.- 2 Design Constraints.- 3 Review of NiTi SMA Stent Designs.- 4 Test Requirements.- 5 Clinical Applications.- 6 Future Development.- References.- Shape-Memory Alloy for Interventional Stenting in View of Its Development in China.- 1 Introduction.- 2 Structural and Material Considerations for the Stent Design.- 3 SMA Stent and Its Application in China.- 3.1 Nonvascular Applications.- 3.2 Vascular Applications.- 4 Discussion and Comments.- 4.1 Systematic Clinical Investigations.- 4.2 Stent Manufacture.- 4.2.1 Geometric Considerations.- 4.2.2 Mechanical Performance.- 4.3 Stent-Material Preparation.- 4.3.1 Bulk-Material Production.- 4.3.2 Surface Preparation.- 5 Summary.- References.- Other Medical Applications.- An Implantable Drug Delivery System Based on Shape-Memory Alloys.- 1 Introduction.- 2 Design of a Delivery System for Solid Drugs.- 2.1 Introduction.- 2.2 Design of a Drug-Delivery Device for Solid Drugs.- 2.3 Conclusion on Solid Drug Delivery.- 3 Design of a System for Delivery of Liquid Drugs.- 3.1 Introduction.- 3.2 Mechanical Design.- 3.2.1 First Prototype.- 3.2.2 Tube Characteristics.- 3.2.3 Valve Finite-Element Model.- 3.3 First Prototype Building.- 3.3.1 Introduction.- 3.3.2 Electrical Characteristics.- 3.3.3 Design of the Reservoirs and Refill Port.- 3.3.4 Prototype Drug Delivery System.- 4 Operational Tests.- 4.1 System Components.- 4.2 Total System.- 5 Possible Improvements.- 6 Conclusion.- References.