Compression Nailing of Long Bones

Biomechanics: The biomechanical concept of compression nailing consists of the use of an intramedullary device that is inserted into the medullary cavity without jamming and that allows a relative movement of the fragments after locking. First, the implant is firmly attached to the distal main fragment, using conventional locking screws at the nail tip. Next, the other main fragment, which contains the nail entry portal, is fixed via a locking screw in a longitudinal slot in the nail. The compression screw is inserted, and produces distraction between the proximal part of the nail and the locking screw in the slot. This distraction results in relative movement between the intramedullary nail and the proximal fragment, compressing the fixed distal fragment against the proximal. Indications: Whether or not compression nailing can be used depends on the axial stability of the fracture or osteotomy. Therefore, simple fracture patterns, nonunions and elective osteotomies are excellent indications. The same is true for fusions of the knee or the ankle joint, providing that there are no major bone defects. Benefits: The chief benefits of compression nailing are controlled fragment apposition, and superior stability, especially to rotational forces, as compared with conventional intramedullary nailing techniques. The favorable biomechanical conditions provided allow early full weight bearing, and ensure a high rate of bony union. With implants and instruments optimized for compression nailing, this technique should widen the scope and enhance the outcome of intramedullary nailing.