Biomechanical And Clinical Study On The Treatment Of Vertical Femoral Neck Fracture By The Technique Of Static Compression Screw With Medial Support

1.Purpose:The purpose of this study is to investigate the effect of a new configuration of cannulated compression screws on the treatment of vertical femoral fracture.Provide a new method and a new thinking for orthopedist to treat with these kinds of fractures.2.Methods:Ordinary cannulated compression screw has infinity ability of pull strength.And the headless cannulated compression screw has more sustainable ability.We combined the two kinds of screws to exert their superiority to achieve the purpose that optimizing the treatment of vertical femoral neck fracture.a.At first,clinical retrospective study is showed.The purpose is to investigate the clinical results of the existing cannulated compression on the treatment of vertical femoral neck fracture,and we found the deficiencies.b.Biomechanical study: 20 synthetic femur models of femoral neck fractures with 20° of VN angle were divided into two groups.Three ordinary cannulated compression screws with the configuration of equilateral triangle is defined as experimental group.An ordinary cannulated compression screw with two headless cannulated compression screws with the configuration of equilateral triangle is defined as control group.Each model was tested the maximum load to failure and the axial compressive load at loading rate of 2 mm/minutes.c.Clinical prospective study: 59 patients underwent vertical femoral neck fracture were completed the follow-up of anteroposterior pelvic and lateral radiographs.Of those 28 patients of experimental group;31 of control group.3.Results: a.The results of biomechanical study: the compressive strength of experimental group is 123.49±15.13N/mm,the maximum load to failure is446.85±76.25 N.The compressive strength of experimental group is109.92±10.81N/mm,the maximum load to failure is 302.92±80.46 N and have statistically significance.b.The results of clinical prospective study: 1fracture non-union and 5 fixation failure occurred in the experimental group.And the number of patients of control group were 7 and 13 respectively.4.Conclusion: The results of this study shows that using an ordinary cannulated compression screw plus two headless cannulated compression screws to treat vertical femoral neck fracture,no matter with biomechanical or clinical study performed its superiority.This fixation method could be introduced an effective method to treat with vertical femoral neck fracture and also provide a new thinking for orthopedist.