Anatomic reductions are rarely achieved for severely displaced pilon fractures and this portends severe osteoarthritis.

Abstract

To evaluate the association between initial articular displacement, postoperative residual articular displacement, and the development of severe osteoarthritis in pilon fractures. A retrospective review was performed of adults with operative pilon fractures (OTA/AO 43) at a level I trauma center. Three surgeons reviewed injury, postoperative, and follow-up radiographs to grade initial articular displacement as <2 mm, 2-5 mm, or >5 mm, postoperative residual articular displacement as 0 mm, ≤2 mm, or >2 mm, and the osteoarthritis (OA) grade as 0 (none), 1 (doubtful), 2 (minimal), 3 (moderate), and 4 (severe). The associations between initial displacement, residual displacement, and the development of severe OA were evaluated. There were 115 patients with pilon fractures included. Initial articular displacement on injury radiographs was associated with residual articular displacement with 100.0% (28/28) of patients with <2 mm of initial articular displacement having 0 mm of residual articular displacement, compared to 51.7% (15/29) and 17.2% (10/58) of patients with 2-5 mm and >5 mm of initial articular displacement (p<0.0001). The development of grade 4 OA was associated with both initial articular displacement (p<0.0001) and residual articular displacement (p<0.0001). All patients with an initial articular displacement <2 mm achieved anatomic reductions with no cases of grade 4 OA. In contrast, grade 4 OA developed in 66.7% (4/6) and 85.7% (18/21) of patients with an initial articular displacement of 2-5 mm and >5 mm that also had a residual articular displacement of >2 mm. Severely displaced articular injuries were less likely to receive anatomic reductions and more likely to develop severe OA.