Devices and methods for treating fractures using intramedullary nails and screws are provided. An intramedullary nail and fixation device can be capable of holding a bone out to length when it is broken in a manner that allows shortening of and/or compressing a bone to promote healing. The device can include a flexible nail with a first leading end and a second end, the nail having a threaded outer surface along at least a portion of a length of the nail. A method for treatment of fractures of long bones having a medullary canal can include creating a hole into an end of a bone to be compressed, inserting a leading end of such a flexible nail into the hole, and rotating the nail to advance the nail through the medullary canal.