Introduction: Operative management of displaced trimalleolar ankle fractures is indicated; however, controversy exists on the optimal strategy for the posterior malleolar (PM) fragment. Two common techniques for PM fixation include posterolateral buttress plating (PL) and fixation with anterior to posterior percutaneous lag screws (AP). To date no study has compared patient and surgical outcomes. Methods: Between October 2002 and January 2010, 45 patients sustained trimalleolar ankle fractures and underwent operative fixation of all three fragments. Twenty-five patients underwent PL plate fixation of the PM and 20 patients were treated with AP lag screws. These patients were asked to participate in an IRB approved study, in which they were recalled for functional and physical assessment. Results: Overall, study consent was successful for 29/45(64%) patients at a mean duration of 45months (range=15-99). The follow-up in the posterolateral (PL) group was 68% and AP lag screws was 60% (p=0.76). While the mean duration of follow-up was 54 months in the PL group and 32 months in the AP group (p=0.08).The PL cohort had significantly better scores for the SMFA bother index (p=0.05). There was also a trend toward improved outcomes for the PL cohort in the SMFA functional index (p=0.11), as well as, the mobility sub score (p=0.11). Conclusion: Both PL and AP fixation appears to be effective constructs for bony union; however, the PL technique resulted in a significantly better SMFA bother index score and a trend towards better SMFA functional index score and mobility sub score.