Does Anterior Impaction Affect Radiographic Outcomes of Pilon Fractures?

The outcomes of pilon fractures are multifactorial. Anterior articular impaction requires sagittal plane correction (anterior distal tibia angle (ADTA)) with articular reduction. However, there is a risk of avascular necrosis of the articular fragments and postoperative tibiotalar arthritis. The purpose of this study was to determine if the presence of anterior impaction affects radiographic alignment after definitive fixation.

Retrospective cohort study of patients who underwent operative management for pilon fractures at two academic, level 1 trauma centers between September 2005-September 2016. Fractures were categorized as having anterior impaction or no anterior impaction after review of preoperative radiographic and computer tomography imaging. Patient demographics and postoperative time to union was recorded. Quality of reduction was measured using (ADTA) (degrees), lateral distal tibia angle (LDTA) (degrees), and lateral talar station (LTS) (millimeters) from postoperative radiographs. Statistical analysis compared fracture patterns with anterior impaction to those without.

208 patients met inclusion criteria. 132 fractures (63.4%) were determined to have anterior impaction. Cohorts were similar in demographics and medical comorbidities (p>0.05). Mean ADTA, LTDA, and LTS for the anterior impaction group 83.5°, 89.7°, and 2.4mm versus 84.6°, 89.9°, and 2.0mm in the group without anterior impaction. Cohorts significantly differed in ADTA(p=0.01), but not LDTA(p=0.12) or LTS(p=0.44). No significant differences were found between cohorts with infection (>0.05), nonunion(p=0.76), unplanned reoperation(p=0.56), or amputation(p=0.34).

This study demonstrated no significant differences in the coronal or sagittal plane alignment when comparing definitively fixed pilon fractures with and without anterior impaction. Additional studies are needed to evaluate the longterm clinical impact of failing to restore ADTA. Level of Evidence: III.