Schatzker IV tibial plateau fractures involving the posterolateral column: Higher incidence of lateral meniscus and anterior cruciate ligament injuries with suboptimal postoperative outcomes

Background: Current literature offers scant insights into Schatzker IV tibial plateau fractures (TPFs) that affect the posterolateral (PL) column. This study seeks to elucidate the prevalence of meniscal and ligamentous injuries in the knee, as well as the clinical outcomes, in Schatzker IV TPF cases, both with and without PL column involvement. Methods: We conducted a retrospective analysis of clinical and imaging data from patients with Schatzker IV TPFs who received surgical treatment at our institution between January 2018 and January 2022. Patient demographics and surgical details were meticulously documented. The study participants were categorized into two groups based on the involvement of the PL column in the Schatzker IV TPF. Group A comprised patients without PL column fractures, whereas Group B included those with such fractures. We compared soft tissue injuries affecting knee stability, namely meniscal and ligamentous injuries, between two groups using Magnetic Resonance Imaging (MRI) and surgical records. Further, Group B was divided into subgroups based on the presence or absence of knee subluxation. Within Group B, we measured the lateral plateau depression (LPD) and lateral plateau widening (LPW). Additionally, we investigated the frequency of meniscus entrapment in patients with PL column fractures. Clinical outcomes were assessed using The American Hospital for Special Surgery (HSS) and Rasmussen scores. Results: The study comprised 66 patients with Schatzker IV TPFs. Of these, 12 patients had no PL column fracture, while 54 had a PL column fracture. Group B demonstrated a 57.4 % and 64.8 % incidence of lateral meniscus (LM) and anterior cruciate ligament (ACL) injuries, respectively, significantly higher than that in Group A (25 %, 8.3 %) (p = 0.044, p < 0.001). Within Group B, those with knee subluxation showed a marked increase in LPD (14.5 +/- 5.3 mm) and LPW (9.3 +/- 4.9 mm), correlating with a higher rate of meniscus entrapment (76.0 %) (p < 0.001). Patients in Group B had lower HSS and Rasmussen scores compared to Group A (p = 0.048, p = 0.006). Conclusion: This investigation reveals that Schatzker IV TPFs involving the PL column are highly associated with increased rates of LM and ACL injuries. Additionally, these fractures correlate with a greater likelihood of knee subluxation and meniscus entrapment, ultimately leading to poorer prognostic outcomes.