Intramedullary nailing of metaphyseal fracturesThe medullary canal of femur and tibia has its lowest diameter in the middle third of the shaft. Proximal and distal of the isthmus, the medullary canal widens to reach its largest diameter near to the metaphysis. Nailing of fractures at the isthmus therefore differs from nailing of proximal or distal fractures. Whereas the nail is incarcerated in the isthmus, it is not in the more proximal and distal sections of the bone. In the middle third of the shaft, the nail is in close contact with the inner cortex. The proximal and distal bone segments are realigned due to nail insertion. In the proximal and distal third, some space between the nail and the inner cortex remains. The fracture segments are not automatically realigned during nail insertion. As there is more space for the implant, it can be located eccentrically, outside the longitudinal axis of the medullary canal. Axis deviation of the broken bone is the consequence. To prevent malalignment every fracture, which is localized closer to the joint, has to be reduced before the nailing procedure starts and this reduction needs to be secured during nail insertion. When a proximal or distal fracture is not reduced, the interlocked nail will fix the fracture and axis deviation (25).Reduction of the fracture and protection of reduction during nail insertion asks for preoperative planning. This planning involves understanding of the fracture through analysis of the fracture type and fracture plane in two X-rays, which are taken perpendicular to each other. The different steps of fracture reduction and nail insertion have to be planned including instruments and implants needed for each step (3). Nailing of fractures near to a joint therefore ask for individual solutions involving a whole armamentarium of surgical techniques.
Metaphyseal fractures of the femurProximal femur fractures represent a specific biomechanical challenge because of the center-column-diaphysis (CCD) angle, which moves the axis of load medial to the longitudinal axis of the femur. In this review, we exclude pertrochanteric and intracapsular femur fractures, as they need specific consideration. We here focus on fracture types, which start at the level of the lesser trochanter, the last regularly being involved in the