Review Question - QID 220482

The arrow is pointing to the anterolateral (Chaput) fragment, where the anterior inferior tibiofibular ligament (AITFL) originates on the tibia. (Answer 2)

Pilon fractures are common injuries typically associated with high-energy mechanisms involving an axial load applied to the foot, leading to comminuted fractures of the tibial plafond. The articular fractures often follow a predictable pattern, with the main fragments typically associated with attachment sites for ligamentous structures about the ankle. Namely, the posterior inferior tibiofibular ligament (PITFL) attaches to the posterolateral (Volkmann) fragment, while the AITFL attaches to the anterolateral (Chaput) fragment. Understanding the periarticular anatomy and common fracture planes encountered in these injuries is critical to accurate reduction and reconstructive efforts.

Tornetta et al. performed a study focusing on the use of CT scans for preoperative planning in 22 patients with pilon fractures. They found that CT scans provided critical additional details not evident on plain radiographs and could characterize the precise orientation of fracture lines and the presence of anterolateral and posterolateral fragments with the potential to influence surgical planning. As a result, the operative approach was altered in 64% of cases, with a lateral incision chosen based on a fracture angle less than 90 degrees. They concluded that potential surgical plan-altering information may be gleaned from preoperative CT scans in patients with pilon fractures.

Cole et al. aimed to define the fracture patterns and comminution zones in OTA/AO type 43C3 tibia pilon fractures using CT scan images from 38 patients. They found a consistent Y-shaped major fracture line pattern, with 95% of cases showing comminution primarily in the central and anterolateral regions. This consistent pattern suggests three main fracture fragments and highlights common areas of bone impaction. They concluded that their findings may improve surgical approaches and implant design by providing a predictable fracture map for preoperative planning.

Figure A is an axial CT image of a tibial plafond fracture with three distinct fragments (anterolateral, posterolateral, and medial) with evidence of central impaction.

Incorrect Answers:
Answer 1: The anterior talofibular ligament (ATFL) originates from the fibula and inserts on the talus
Answer 3: The interosseous ligament is a thickening of the distal tibiofibular syndesmosis and does not insert on the anterolateral tibial plafond
Answer 4: The inferior transverse ligament courses along the PITFL and inserts on the posterolateral tibial plafond
Answer 5: The tibionavicular ligament is a part of the deltoid ligament complex and originates from the medial malleolus