Summary

Tibial plateau fractures (TPF) are complex injuries, with no prior reports of associated posteromedial (PMC) or posterolateral corner (PLC) injuries. In this study of 359 patients, 61.3% had PMC or PLC injuries, and 7.02% required surgery. PLC injuries were linked to fracture-dislocations, while arcuate fractures were protective against PMC injuries. This is the first incidence rate report of PMC/

Abstract

Introduction

Tibial plateau fractures (TPF) are complex injuries that can lead to joint instability. Up to 63% of these fractures are associated with lateral collateral ligament injuries and up to 29.6% with medial collateral ligament injuries; however, no reports of posteromedial (PMC) or posterolateral corner (PLC) associated injuries have been found. The main objective was to determine the incidence rate (IR) of PMC and PLC injuries in TPF. The secondary objective were to identify risk factors for injury and the surgical intervention rate of PMC/PLC in TPF.

Methods

Retrospective cohort study of patients with TPF who underwent surgery between June 2016 and July 2023. Inclusion criteria: patients over 18 years old, TPF with preoperative X-ray, CT scan, and MRI, with at least 12 months of follow-up. Exclusion criteria: a history or presence of fractures around the knee or prior PMC/PLC injuries. TPF were classified according to Schatzker, AO, Frosch and Hohl & Moore criteria and concomitant arcuate and proximal fibula fractures were recorded. PMC and PLC injuries records included affected structures, location, severity and whether concomitant or deferred surgical intervention was performed. Lateral and medial plateau compression fracture patterns were analyzed as potential risk factors for PMC and PLC injuries, respectively. Statistical analysis was performed with type I error rate of 5%, using STATA 18.0.

Results

Out of 539 TPF cases, 359 met the selection criteria. Average patient age was 43.56 years old (17 - 7573), 54% were male. 220 patients (61.3%) had corner injuries, with 105 (29.3%) presenting PMC injuries, 172 (47.9%) PLC injuries, and 59 (16.4%) both. Of the corner injuries, 12 (7.02%) of PLC and 9 (8.65%) of PMC injuries required surgical intervention (SIR). A positive association was identified between fracture-dislocations and PLC injuries (OR 1.54, p=0.0002) and a negative association between PMC injuries and arcuate fractures (AF) (OR 0.18, p=0.02).

Discussion

The IR of PMC injury was 29.3% and 47.9% for PLC, with an overall surgical intervention required in 5.85% of cases. Fracture-dislocation cases had a higher risk of PLC injuries, and AF was a protective factor for PMC injuries. To the authors' knowledge, this is the first report of PMC or PLC injuries in TPF.

Conclusion

PMC and PLC injuries in the context of TPF have a high incidence rate, with PLC injuries increasing in cases associated with fracture-dislocations and PMC injuries decreasing in cases with arcuate fractures.