Biocompatible Insert for Anchoring Intramedullary Rods



Our team was tasked with improving Derotational Femoral Osteotomies, a surgery usually performed on children with excessive in-toeing or out-toeing caused by a malrotated leg bone. During surgery, an intramedullary rod is placed in the femur to fix its angle of rotation, but many patients experience a relapse in malrotation after the surgery. Our team identified that this is largely due to a loose fit between the intramedullary rod and interlocking bone screw, which allows the rod to rotate inside the bone post-operatively.

Our solution is a biocompatible plastic insert in the hole in the intramedullary rod through which the interlocking screw passes. The screw threads into the insert instead of empty space, anchoring the lower femur to the rod and preventing unintended rotation.

Our biocompatible insert (blue) within the intramedullary rod.