A 63-year-old man with a comminuted spiral femoral shaft fracture was treated with closed reduction and internal fixation with a cephalomedullary nail. Two weeks postoperatively, one of the two static distal interlocking bolts began backing out and was removed. The nail ultimately migrated distally and perforated the knee joint at four months postoperatively. The patient was successfully treated with an exchange nail and percutaneous bone graft to the fracture site. A single static distal interlocking bolt may be inadequate to maintain length in a healing comminuted spiral femur shaft. Multiple distal interlocking bolts should be in place until the completion of fracture healing.