Nail-based compliant hip fixation system

A method of hip fixation, the method comprising, in any order:

• placing an intramedullary nail longitudinally in a proximal femur of a subject, the nail containing a sleeve;
• and
• placing a fixation element into the proximal femur and through the sleeve, such that the fixation element is slideable along its long axis in the sleeve and extends out of the nail to a head of the proximal femur and is anchored in the head;
• wherein a compliant member is located in the nail and is configured to deform reversibly in response to a load applied to the head of the proximal femur by the subject, to reversibly change an angular orientation of the fixation element with respect to the nail, and
• wherein the angular orientation is defined as an angle formed between a long axis of the nail and the long axis of the fixation element.

A system for hip fixation, comprising:

• an intramedullary nail configured to be placed longitudinally into a proximal femur of a subject;
• a fixation element configured to be placed into the proximal femur and transversely through the nail, such that the fixation element is slideable along its long axis in the nail and extends out of the nail to a head of the proximal femur and is anchored in the head;
• and
• a compliant member located in the nail and configured to deform reversibly in response to a load applied to the head of the proximal femur by the subject after the nail and the fixation member have been implanted in the proximal femur of the subject, to reversibly change an angular orientation of the fixation element with respect to the nail;
• wherein the angular orientation is defined as an angle formed between a long axis of the nail and the long axis of the fixation element, and
• wherein the compliant member is formed of material selected from the group consisting of (a) metal and (b) a composite including a polymer matrix containing carbon fibers.