Biomechanical Analysis of Trochanteric Fracture Fixations Using a Y-Shaped Locking Plate

Objectives:Clinical evidence suggests that the use of Y-shaped locking plates with anterior and lateral locking screws provide improved primary fixation stability over the use of straight locking plates in the treatment of greater trochanter (GT) fractures. However, it remains unclear how the use of cable cerclages, in replacement or addition to the locking screws, would impact the primary fixation stability.Methods:Nine surgical fixations were tested on a dynamic test bench through 27 sawbones experiments. These fixations on the GT and bone shaft (BS) included locking screws alone, cable cerclages alone, or 7 combinations of both. Migrations, defined as the remaining movements of the unloaded GT fragment, were measured for all 9 fixations submitted to dynamic stair climbing cycling after an experimental plan.Results:Under dynamic stair climbing conditions: (1) Y-shaped locking plates fixed by locking screws alone (vs cable cerclages alone) significantly reduced GT migrations, (2) adding cable cerclages to screws provided no significant reduction of migrations, and (3) cable cerclages alone can be used on the BS but is not recommended on the GT.Conclusions:Y-shaped locking plates with anterior and lateral locking screws improved primary stability of GT fractures over fixation with cable cerclages. Cable cerclages provided acceptable primary stability when screw fixations were unachievable but on the BS only.