Biomechanics of implant augmentation

The rising incidence of osteoporotic fractures requires novel treatment strategies. Implant augmentation with bone cement is considered to be a promising approach but the benefits and risks need to be carefully evaluated. Experimental investigation of the biomechanical potential and the associated risks with special reference to the osteoporotic proximal femur and proximal humerus. Even small amounts of bone cement (3 ml) applied to the proximal femur in combination with intramedullary nailing led to more than a 50 % increase in the number of test cycles before failure. The heat and pressure generated in the bone did not exceed critical thresholds. Short to midterm effects of subchondral cement placement on the adjacent cartilage can be excluded. The risk for cement leakage needs to be considered. Implant augmentation offers high biomechanical potential to prevent mechanical complications after fracture fixation in osteoporotic bone. Early and confident mobilization of elderly patients therefore appears to be possible. With appropriate handling, associated risks seem controllable; however, implant augmentation cannot be applied as a routine concept for osteoporotic fracture management. The application requires careful evaluation on a case by case basis under comprehensive consideration of mechanical and biological factors.