Rationalising the use of distal fibula locking plates in ankle fracture fixation

P. Vaughan, G. Salt, V. Thorisdottir, S. Deakin

Introduction: Despite costing up to 5X more than a one-third tubular plate (TTP) and no absolute indications, distal fibula locking plates (DFLP) are becoming increasingly popular in the fixation of ankle fractures, particularly in the elderly. We reviewed all our distal fibula fracture fixations, over the course of one year, in order to rationalise DFLP use.

Methods: Patient demographics, Weber classification, use of DFLP or TTP and the mode of fixation were recorded. Open fractures and tibial plafond fractures were excluded.

Results: 51/84 (61%) of patients had DFLP fixation of their distal fibula fracture, the majority (44/51) of which were for Weber B fractures. The DFLP was used in bridge mode for 12 Weber B fractures and in neutralisation mode for remaining 32.
There was a significant difference in age between the DFLP and TTP groups for all fractures (p< 0.005) and for Weber B fractures treated in bridge mode (p=0.036), but not for Weber B fractures treated with a lag screw/ neutralisation plate (p=0.09).

Discussion: In 32/44 of our cases, we used the DFLP to neutralise a lag screw. However DFLP are only of mechanical benefit when adequate fracture compression is not obtained either due to fracture comminution or due to osteoperotic bone, often seen in the elderly. All 32 of these Weber B fractures were amenable to a lag screw and were not comminuted. There was also no significant age difference between this group and the group of Weber B fractures that were treated with a lag screw/ neutralisation plate. In these cases therefore, the DFLP did not offer any mechanical advantage.

Conclusion: We propose limiting the use of the DFLP to fibula fractures where intra-fragmentary compression cannot adequately be obtained, thus reducing our use by over 60% and significantly reducing our implant costs for such injuries.