[Intramedullary nailing of the distal tibia. Does angular stable locking make a difference?]

Osteosynthesis of distal tibia fractures relies on stable fixation of the distal fragment. Modern intramedullary implants provide various fixation options for locking screws. These implants expand the indications for intramedullary nailing of tibia fractures towards more distally located fractures.

The most essential options which improve the fixation of the distal fragment include an increase in number, in size and in spacing of the distal locking screws. Further options for nailing of distal tibia fractures include interfragmentary compression and angular stability. Interfragmentary compression considerably increases mechanical stability in axially stable fracture situations. Angular stable fixation of the locking screws has recently become a popular feature in intramedullary nailing; however, the effect of angular stability on the mechanical properties of distal tibia osteosynthesis has been found to be limited.

The initial stability to provide sufficient load bearing capacity appears to be provided by the available locking options. With at least two screws, preferably in crossed configuration and spaced over the largest available distance of the distal fragment, secure and stable fixation can be achieved. Insertion of the locking screws in a free hand technique typically results in jamming of the locking screw with the nail and with cortical bone, providing inherent angular stability of the construct. Angular stable locking features of the nail itself do not appear to improve mechanical stability or to affect healing of distal tibia fractures.