Nitinol Curve: Intramedullary Fixation for Small Bone Fractures

Reference #:

2008-014

Inventors/Contributors

Scott F.M. Duncan, M.D.

Description

A fracture fixation system particularly useful for bones of the hand and foot is disclosed. The system uses curved shape-memory alloy (e.g., Nitinol) wires that have a predetermined radius of curvature to accommodate different sized bones. These shape-memory alloy wire forms can be inserted into phalanx, metacarpal or metatarsal bones via a percutaneous technique. The technique uses small skin incisions; a specialized drill guide that has holding K-wires to maintain fixation of the drill guide to the bone so that it does not lose the insertion point; a specialized drill as well as a specialized wire cutter and advancement tool to make sure that the level of the wire is below the level of the outer cortical bone. Shape-memory alloy (e.g., Nitinol) based wires with a pre-bent curve have an advantage over the typical standard K-wire in that they can spring back to their predetermined memory shape when inserted into the intramedullary canal of the bone and heated, i.e., a more aggressive curve. By increasing their bending or flexion to increase the arc of curvature, this allows fixation points for the wire, essentially locking it to bone.

Patent Status

Pending