Relationship of Fracture Morphological Characteristics with Posterolateral Corner Injuries in Hyperextension Varus Tibial Plateau Fractures.

BACKGROUND Hyperextension varus tibial plateau fracture (HVTPF) is known to present with concomitant injuries to the posterolateral corner (PLC). However, the exact rate and characteristics of these injuries remain unclear. The primary objective of this study was to explore the rate and characteristics of PLC injuries in HVTPFs. The secondary objective was to investigate the relationship between the fracture morphological features and the associated PLC injuries. METHODS Patients with HVTPFs were subdivided into 2 groups: group I (without fracture of the posterior column cortex) and group II (with fracture of the posterior column cortex). Fracture characteristics were summarized qualitatively based on fracture maps and quantitatively based on the counts of morphological parameters. Knee ligamentous and meniscal injuries were assessed using magnetic resonance imaging. The association between fracture characteristics and PLC injuries was analyzed. RESULTS We included a total of 50 patients with HVTPFs in our study: 28 in group I and 22 in group II. The rate of PLC injuries was 28.6% in group I and 27.3% in group II. In group I, patients with PLC injuries showed fracture lines closer to the anterior rim of the medial plateau and had smaller fracture areas. Furthermore, 6 of the 8 patients with PLC injuries in group I also had posterior cruciate ligament injuries. CONCLUSIONS The rate of PLC injuries is relatively high in HVTPFs. In HVTPFs without fracture of the posterior column cortex, a small fracture area strongly suggests an accompanying PLC injury, and PLC injury is frequently combined with posterior cruciate ligament injury. LEVEL OF EVIDENCE Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.