Interlocking nailing of complex fractures of the femur and tibia.

The interlocking nail widens the range of indications for medullary osteosynthesis of femoral and tibial shaft fractures. Stability is achieved by transverse threaded bolts in prefabricated holes in the nail, which anchor the implant directly to cortical bone, thereby controlling length, alignment, and rotation of the limb. Two hundred eighty-three femoral and 401 tibial fractures were treated with an interlocking nail and followed for an average of 20 months. Overall, 97% of the femurs and 94.3% of the tibias were judged to have an excellent or good result, based on both clinical and radiographic parameters. Delayed union or nonunion requiring bone grafts occurred in 2% of the femurs and 0.7% of the tibias following interlocking nailing. Deep infection developed in 2.4% of the femurs and 2.2% of the tibias. All of these patients eventually healed their fractures without evidence of chronic osteomyelitis. The main advantage of interlocking nails is that surgery can be performed using closed nailing techniques, allowing early protected weight-bearing and joint motion. The rates of nonunion and infection are very low, and there is little risk of refracture after implant removal.