Surface coating to improve the metal-cement bonding in cemented femur stems

Introduction

Hydrolytic debonding of the metal-cement interface is one of the main reasons for aseptic loosening in cemented hip arthroplasty.

Materials and methods

BiContact femur stems (CoCrMo-/TiAl₆V₄-alloy) were coated by a silica/silane interlayer coating system. The stems were cemented into artificial femurs. The cyclical loading (DIN ISO 7206-4) was performed within a hip-simulator. Uncoated stems (CoCrMo-/TiAl₆V₄-alloy) were prepared and loaded the same way. After loading, the metal-cement and the bone-cement interfaces were analysed. Unloaded uncoated and unloaded coated BiContact stems served as a control.

Results

The coated loaded stems showed a significant reduction in debonding and cement failure (P ≤ 0.05). A high correlation was documented between debonding and cement failure (r _Spear ≥ 0.9). There was no significant difference between CoCrMo- and TiAl₆V₄-stems (P ≥ 0.05).

Conclusion

The silica/silane coating significantly decreased hydrolytic debonding at the metal-bone cement interface with consecutively less cement failure.