A new technique for the distal locking of solid AO unreamed tibial nails.

Proximally mounted distal aiming systems have failed primarily because of nail deformation during insertion. A mechanical aiming device for the insertion of distal locking screws for solid unreamed AO tibial nails was developed and was tested in twenty unreamed solid tibial nailing procedures in a video-documented prospective clinical study. The rate of accurate screw placement, time expended, complications, and outcome for each patient were recorded. Distal locking was performed successfully in all cases without image intensification. Although a high percentage (55%) of fractures were open, the total mean operative time was 108 minutes (range, 60 to 180 minutes) and the mean time for distal locking (three screws) was 15.5 minutes (range, 8.0 to 39.0 minutes). Notable drill-nail contact occurred in 15 percent of the distal screws placed, demonstrating accurate aiming and drilling. There were no major intra- or postoperative complications related to the distal aiming system.