Open fixation of the posterior malleolus increases the morbidity of trimalleolar ankle fracture fixation.

purposeTo assess the morbidity of open reduction internal fixation (ORIF) of posterior malleolus fractures (PMFs) in the setting of trimalleolar ankle fractures.

methodsA retrospective review of 79 trimalleolar ankle fractures was performed to identify need for syndesmotic fixation, blood loss, operative/tourniquet time, complications, and reoperations. Patients with PMF ORIF (n = 38) were compared to those with no fixation (n = 41). A subanalysis of patients with small PMFs (< 25%) was performed.

resultsThe PMF ORIF group required less syndesmosis fixation (proportional difference (PD) - 44.6%, 95% confidence interval (CI) - 61.8 to - 23.0%), had more blood loss (MD 20 ml, CI 0-40), longer operative times (MD 53.0 min, CI 35.9-70.1), longer tourniquet times (MD 26 min, CI 4-33), and had no difference in postoperative joint step-off or concentrically reduced joints. The PMF ORIF group had more postoperative complications (PD 26.9%, CI 6.3-44.8%) and a trend for more reoperations (PD 13.6%, CI -3.4 to 29.6%). Wound complications were more common in the PMF ORIF group (PD 26.5%, CI 6.9-43.6%), resulting in 5 (16.1%) irrigation and debridement procedures. On analysis of patients with small PMFs (n = 42), PMF ORIF (n = 15) resulted in longer operative/tourniquet times and had no observed difference in postoperative joint step-off, concentrically reduced joints, need for syndesmotic fixation, blood loss, or complications/reoperations.

conclusionPMF ORIF in the setting of trimalleolar ankle fractures was associated with increased operative/tourniquet times, blood loss, wound complications, and did not eliminate the need for syndesmosis fixation.