Contained femoral defects: biomechanical analysis of pin augmentation in cement

Although in the proximal tibia the need for pin augmentation of cemented giant cell tumor defects depends on whether the defect is contained, there is controversy regarding the role for pins in the distal femur. The current study investigated whether Steinmann pin augmentation offers biomechanical advantages in cement reconstruction of contained defects of the lateral femoral condyle. Twelve pairs of human femurs were used. They were tested either with the bone intact, with a standardized contained defect in the lateral condyle, with a defect repaired with cement alone, and with a defect repaired with pins in the cement. Intact specimens had significantly higher load to failure than specimens with a defect. In the repaired specimens there were no significant differences in stiffness, peak load to failure, and energy to failure between the specimens repaired with just cement or augmented with pins. This study did not show any significant biomechanical advantage of this configuration of Steinmann pin reinforcement in cement for contained defects of the lateral femoral condyle.