Nickel–titanium wire as a flexor tendon suture material: an ex vivo study

Nickel–titanium shape memory alloy (NiTi) is a new suture material that is easy to handle, is strong, and biocompatible. The purpose of this study was to evaluate the material properties and biomechanical behaviour of 150 µm and 200 µm NiTi wires in flexor tendon repair. Braided polyester (4-0 Ethibond®) was used as control. Fifty fresh-frozen porcine flexor tendons were repaired using the Pennington modification of the Kessler repair or a double Kessler technique. NiTi wires were stiffer and reached higher tensile strength compared to braided polyester suture. Repairs with 200 µm NiTi wire had a higher yield force, ultimate force and better resistance to gapping than 4-0 braided polyester repairs. Repairs made with 200 µm NiTi wire achieved higher stiffness and ultimate force than repairs made with 150 µm NiTi wire.