Using Blocking Screws to Improve Antegrade Interlocking Intra-medullary Nail′s Fixation Effect in the Treatment of Femoral Lower-middle Section Fracture

Objective To discuss the therapeutic effect of blocking screws, when they were used to improve femoral antegrade interlocking intra-medullary nail's fixation, and to compare different influence of the knee joint between femoral antegrade intra-medullary nail and retro-grade intra-medullary nail. Method From June 2009 to June 2012, we chosed 52 patients with femoral lower-middle section fracture. Among these patients, 28 cases were fixed with antegrade intra-medullary nails combined with blocking screws, some in one-stage operation and other in two-stage operation. 24 cases were fixed with retro-grade intra-medullary nails. All of these two groups' patients were followed up for 12-20 months. Furthermore, their knee joint Merchant scores were assessed after bone fractures cured. Result Fractures of first group, who were received the fixation of antegrade intra-medullary nails combined with blocking screws, were all cured completely during the follow-up. Some two-stage operation patients, their fracture fixation were improved obviously after adopting blocking screws in motorization. But there were 4 cases in another group, whose fractures were still not healed during the follow-up.1 cases with infection in the knee joint, another 2 case with joint loose bodies. Surgical complication rate was far higher than the previous group. When the knee Merchant scores were assessed, statistical meaning was found between two groups' difference(P0.05). Conclusion Blocking screws can improve antegrade intra- medullary nail fixation effect, increase the stability of fracture and promote the healing. Compared with retro-grade intra-medullary nail, antegrade intra- medullary nail can avoid the injury of knee normal structure and protect knee joint function.