A method for treating a complex fracture with a variable length nail is provided. The nail is configured for at least 5 mm of axial length change in each direction. The method involves making a first hole or incision in the skin of the patient in proximity to a fractured long bone and at least partially clearing a canal through the center of the long bone. The variable length nail is inserted into the canal and securing a distraction shaft and a housing of the nail to separate portions of the fractured long bone. The hole or incision is allowed or caused to close. An external adjustment device comprising at least one rotatable magnet is placed in proximity to the patient's skin. The external adjustment device is operated so that a magnetic field of the at least one rotatable magnet of the external adjustment device causes the rotatable permanent magnet of the variable length nail to rotate, causing either extension or retraction of the distraction shaft relative to the housing.
