ABSTRACT
Objective To study the biomechanics of simple locking proximal femoral plate (LPFP),LPFP combined with calcium phosphate cement (CPC) and proximal femoral nail antirotation (PFNA) in treatment of unstable intertrochanteric fractures.Methods Thirty-six femurs from 18 specimens with no pathological defects,fractures,malformations or neoplasms were enrolled in the study and were divided into three groups (Groups A,B and C),with 12 femurs per group.Intertrochanteric fractures were duplicated in accordance with Evans classification of type Ⅲ A.The fractures in Group A were treated by LPFP combined with CPC fixation,that in Group B treated with only LPFP fixation,while that in Group C fixed with PFNA.A comparative mechanical test of femoral specimens was performed in a special clamp.Results Axial compression test showed linear change of the load-displacement of three surgical fixations for intertrochanteric fractures under biological load.The measurement of torque-torsion angle of three fixations for intertrochateric fractures showed that the torque was enlarged with increase of torsion angle till the failure of internal fixation.Conclusion LPFP combined with CPC or PFNA can attain solid fixation of unstable intertrochanteric fractures.