In our case series of split and depression type of tibial plateau fractures, we were able to identify the wide heterogeneity under various subheadings. Therefore, with the available information, it would not be wrong to say that the knee injuries classified as Schatzker type-II fracture are a group of morphologically split and depression types of lateral tibial plateau fracture with variation in the pattern of displacement, fracture location, and associated injuries. Millar et al [7] in their recent systematic review proposed that it is imperative to evaluate the tibial plateau fracture morphologically, topographically, the pattern of displacement, and associated injury to ligaments for comprehensive understanding.
Morphologically all the Schatzker-II fractures are having a cortical split of the lateral tibial plateau and depression of the articular surface. McGonangle et al [10] using the fracture mapping identified that 72% of the lateral tibial plateau fracture has a fracture in the sagittal plane (±22⁰), amenable to fixation with lateral angle stable plate. On the contrary, looking in our series, the classical sagittal plane cortical split was seen in only 20% (n=4) of the cases. However, the other 5 cases having anterolateral quadrant split fracture were also amenable to anterolateral fixation. 55% of the cases were having a dual plane or multiplane split. Having multiple cortical splits involving the anterolateral and posterolateral quadrant, indicate the frequent need for multicolumn fixation or the need for a Hoop plate to stabilize such fracture [11,12, 13].
The possible reason could be explained by the higher velocity of injury in our series. As, classically split and depression fracture is a type of low-velocity trauma [14], whereas all our cases sustained this fracture as a consequence of road traffic accident (RTA) of varying severity, which explains a higher amount of comminution involving the depression fragment and frequent encounter of multiple cortical splits. However, with increasing road traffic accidents, it is a need for time to understand the multiple dimensions of the fracture. Similarly, 40% of the patients were having an injury to either lateral meniscus or grade III injury of the MCL also corroborative to higher velocity of injury [15].
Identification of injuries to meniscus and ligament can be missed in the fracture setting and having a checklist will draw obvious attention. Moreover, this could be helpful to overcome the limitations of the available classifications [7]. In the current study, we were having the intraoperative data to identify the injury to the ligament or meniscus. In the future wherever possible having a preoperative MRI would be more appropriate for detailed and pre-emptive surgical planning [15].
Moreover, the Depression of articular fracture was heterogeneous in regard to the pattern of displacement in the sagittal and coronal plane, comminution, and location in relation to the quadrants. The angular displacement of the articular surface in a sagittal plane not only identifies the varying pattern but also hints at the varying positions of the knee flexion in combination with valgus force leading to lateral tibial plateau fracture [3].
Our study has some limitations because of the retrospective study design and a lesser number of cases. However, our primary objective was limited to identify the heterogeneity of Schatzker type-II fracture. Our findings are very much corroborative to observations of Sun et al [13] they stated that careful study of multiplanar CT images is impeccable, and it would be inappropriate to generalize one scenario for all Schatzker type II fractures. However, to establish the clinical relevance of the fracture heterogeneity would be needing a prospective trial.