INTRAMEDULLARY NAILS FOR LONG BONE FRACTURE SETTING

摘要

An intramedullary nail has a proximal part for engagement with a proximal bone fragment and a distal part for engagement with a distal bone fragment. A motion assembly interconnects the parts and allows limited axial relative motion of the proximal and distal parts. This limited axial motion provides micromotion and in some embodiments also dynamization. The nail may comprise a stem for fastening to one bone fragment and an insert within the stem for fastening to the other bone fragment, the insert being adapted to guide insertion of a bone screw through the stem and to prevent relative rotation of the distal and proximal bone fragments. The motion assembly may include spring bias and/or damping means between the parts, possibly including one or more Belleville washers.