The primary outcome was bone healing time and the secondary outcomes were the rates of delayed union and nonunion, the rates of venous thrombosis of lower limbs, Johner-Wruhs scores, Lysholm knee score, VAS scores, postoperative complications, serum BMP-2, osteocalcin (OC) and bone specific alkaline phosphatase (BS-ALP). This evidence concerns the gene BMP2 and deep vein thrombosis.