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

Area of Science:

• Biomaterials Science
• Orthopedic Surgery
• Materials Engineering

Background:

• Nickel-titanium shape memory alloy (NiTi) is a novel suture material offering ease of handling, strength, and biocompatibility.
• Evaluating advanced materials is crucial for improving surgical outcomes in tendon repair.

Purpose of the Study:

• To assess the material properties and biomechanical behavior of 150 µm and 200 µm NiTi wires in flexor tendon repair.
• To compare NiTi wire performance against braided polyester (4-0 Ethibond) as a control suture.

Main Methods:

• Fifty fresh-frozen porcine flexor tendons were repaired using either the Pennington modification of the Kessler repair or a double Kessler technique.
• Repairs were performed using 150 µm NiTi, 200 µm NiTi, or 4-0 braided polyester sutures.
• Material properties and biomechanical behavior, including stiffness, tensile strength, yield force, ultimate force, and resistance to gapping, were evaluated.

Main Results:

• NiTi wires demonstrated greater stiffness and higher tensile strength than braided polyester sutures.
• Repairs using 200 µm NiTi wire exhibited superior yield force, ultimate force, and resistance to gapping compared to 4-0 braided polyester.
• 200 µm NiTi wire repairs achieved higher stiffness and ultimate force than repairs with 150 µm NiTi wire.

Conclusions:

• Nickel-titanium shape memory alloy (NiTi) wires represent a promising advancement in flexor tendon repair materials.
• The 200 µm NiTi wire offers superior biomechanical properties, including enhanced strength and stiffness, compared to braided polyester and smaller diameter NiTi wires.