Osteonecrosis of the distal tibia after pilon fractures.

Background: Pilon fractures are devastating injuries with high complication rates. Osteonecrosis has been previously described after Weber C fracture-dislocations but has not been reported following fixation of pilon fractures.

Methods: All AO/OTA 43-C pilon fractures from 2007 to 2018 were reviewed. Injury factors and demographics were recorded. Computed tomography (CT) scans of the fracture pattern were analyzed to determine risk factors for ON.

Results: 71 pilon fractures in 69 patients were included. Mean follow-up was 21.6 months. 18 patients demonstrated ON at a mean 7.3 months' post-injury. Regression analysis demonstrated no differences between cohorts with respect to smoking status, open injury, or diabetic status. ON was associated with small anterolateral fragment less than 2.0cm (OR=19.47, p=0.012), higher comminution (OR=3.00, p=0.005), use of calcium phosphate bone substitute (OR=20.72, p=0.013).

Conclusions: ON of the distal tibia was not associated with patient factors but was associated with fracture characteristics.