Abstract: The present invention describes a intramedullary nail that is useful in the repair of long bone fractures, wherein the nail has a flexible state, which allows for the insertion of the nail through any number of incisions that may be off center of the intramedullary canal, and a rigid state, which allows the nail to provide adequate support to mend the long bone. Several embodiments of an intramedullary nail are described, including a nail comprising a shape memory nickel-titanium alloy, which has an austenite start temperature of about 15° C. and an austenite finish temperature of about 35° C., and a nail comprising loosely fitting multiple links that can be tightened to provide rigidity when properly set in the intramedullary canal.