Biomechanical Evaluation Of Femoral Prosthesis Stability After Cemented Hip Arthroplasties With Femur Drilling

Objective: There was a high clinical loosening rate of a cemented femoral stem in artificial hip arthroplasties. To evaluate the biomechanical effects of prosthesis stability after cemented hip arthroplasties with femur drilling. To reduce the loosening rate of femoral component after artificial hip arthroplasties. Methods: Eight matched pairs of embalmed male upper femurs were used. All the specimens were implanted with cemented femoral stem. One femur from each pair was designated as non-drilled group, whereas the femur of the other side served as the drilled group. In the proximal femur, drill several channels in the anterolateral side and appropriate close them to ensure that bone cement could fill channels without spills. After 24 hours, within a servohydraulic testing machine (NWS-1000C& CSS-44020), femoral specimens were fixed to perform the biomechanical test which included the anti-sinking stiffness, anti-torsion stiffness and the greatest loading. Record and compare the femoral stems' displacement, turned angle, the biggest loading of each group separately. The statistical analysis was performed with SPSS 11.5 statistical software. Each group parameters were compared with paired t-test. Results: There was significant difference (P<0.05) of the biomechanical effects between the drilled team and the non-drilled one in anti-torsion stiffness test. With drilling of femur shaft, the anti-torsion stiffness increased by 159 percent, the greatest loading of torsion increased by 103 percent and the greatest loading increased by 67 percent. But there was no significant difference (P>0.05) of anti-sinking stiffness between the two groups. Conclusions: In artificial hip arthroplasty, drilling in shaft of femur increase the intensity through improving significantly overall stability of the prosthesis.