Analysis on Mechanical Characteristics of Femoral Neck Fracture with Different Reduction Qualities / 医用生物力学

ABSTRACT

Objective To investigate biomechanical characteristics of femoral neck fracture with different reduction qualities. Methods Three cases of Sawbones artificial femoral models were selected, and two cases of Pauwel III femoral neck fracture were modeled. Three cannulated screws were inserted into the models in the form of inverted triangle to fix the fracture. Two cases maintained different reduction qualities (defined as Model 1 and Model 2). In the 3 third case, no modeling operation was performed (defined as intact model). Then the strain gauges were respectively pasted on regions of interest of the 3 femoral models. Finally, the femur model was applied with the vertical load on mechanical testing machine. Results When the displacement of femoral head reached 4 mm, the average load of intact model, Model 1 and Model 2 was (236.30±5.35), (196.57±3.56), (69.50±2.95) N, showing significant differences. When the displacement of femoral head reached 5 mm, the average load of intact model, Model 1 and Model 2 was (276.7±3.40)，(232.93±2.64)，(80.83±4.54) N, showing significant differences. Conclusions The lower the reduction quality of the femoral neck fracture, the weaker the ability of the femur to bear stress, the higher the probability of nonunion, re-fracture and femoral head necrosis in the process of postoperative rehabilitation.