Clinical application of TiNi shape memory alloy bone fastener

Titanium-Nickel shape memory alloy (TiNi SMA) has great potential as a biomaterial in orthopaedic applications due to its unique thermal shape memory effects, superelasticity and high damping properties. We designed and manufactured bone fasteners using newly developed TiNi SMA wire (Af, 35±2.C). Several types of bone fastener designs were prepared for the application of orthopedic treatment of bone fracture. We applied this fastener to 82 fracture patients. Fracture types according to the anatomic location included distal fibular (21), femur shaft (periprosthetic fracture, 17), distal tibia (15), distal femur (10), metacarpal bone (9), and subtrochanter of femur (5), distal clavicle (5). Serial radiographs, complete blood count (CBC) and urine analysis were performed postoperatively. Radiological union was achieved without complications at due time after operation. There were no abnormal findings on follow-up CBC or urine analysis. On a subjective level, use and application of the TiNi SMA fastener was not as demanding as conventional fixation methods, such as circumferential wiring (cerclage) or the Dall-Miles technique. The efficacy of SMA bone fastener in this study is very excellent as demonstrated in this clinical study. It gives the new armament to orthopedic surgeon.