Evaluation of Lauge-Hansen designation of Weber C fractures.

Associations between Weber C ankle fractures and pronation external rotation (PER) injuries of the Lauge-Hansen classification have often been incorrectly correlated. The purpose of the present study was to evaluate the Lauge-Hansen designation of Weber C fractures by establishing the proportion of Weber C fractures that are supination external rotation (SER), supination adduction (SA), pronation abduction (PA), PER, and hyperplantarflexion variant fractures. A clinical database of operative ankle fractures treated by the senior author (D.G.L.) was reviewed. The inclusion criteria were patient age older than 16 years, preoperative ankle radiographs, and Weber C fracture designation. A total of 132 patients met the inclusion criteria, and the proportion of PA, PER, SER, SA, and variant fractures among the Weber C fractures was analyzed. PA fractures accounted for 0.8% (n = 1), PER fractures 56.8% (n = 75), SER fractures 35.6% (n = 47), and hyperplantarflexion variant fractures 6.8% (n = 9) of the 132 Weber C fractures. Patients with Weber C-PER fractures were more commonly male (p = .005) and younger (p = .003) and demonstrated a greater fibular fracture height (p < .001) than those with Weber C-SER and Weber C-variant fractures. Our study quantitatively demonstrated that not all Weber C fractures occur secondary to pronation injuries. This distinction is important, because all pronation injuries will demonstrate medial ankle injury, but SER and variant fractures might not. We therefore recommend careful evaluation of the fibular fracture characteristics, including the direction of fracture propagation and the distance from the tibial plafond, when classifying Weber C fractures using the Lauge-Hansen system, because correct classification is vital in preparation for appropriate operative treatment.