Summary

The incidence of associated hidden fractures involving the femoral condyles and proximal fibula in the setting of tibial plateau has been overlooked. A high incidence of these injuries has been identified in our series based on MRI evaluations, and its further clinical relevance should be investigated.

Abstract

The advent of three-dimensional imaging has revolutionized the decision-making and management of articular fractures. Magnetic resonance imaging (MRI), in particular, has added substantial information in detecting subtle bony abnormalities, like bone marrow edema and subchondral fractures. We reviewed 367 MRIs performed in the setting of tibial plateau fractures, aiming to detect associated injuries affecting either the femoral condyles or the proximal fibula. We collected demographic data standardizing the evaluation of the image database. We defined three proximal fibula regions: the head, neck, and shaft and seven injury patterns. Medial and lateral femoral condyles were divided into three thirds: anterior, middle and posterior. In each one we described four injury patterns. Statistical analysis was performed using SPSS 29, chi-square test, and student t-test. 51% of the cases of tibial plateau had a proximal fibular injury. In 39.6% of the cases the radiographs did not identity the associated proximal fibular injury. 94.4% of all fibular fractures involved the head, while 35.5% involved the neck and 8.1% the shaft, respectively. 55.9% of all fibular head fractures were comminuted, followed by 20.2% bone contusion, 12.2% avulsion, 7.4% transverse, 3.7% oblique, and 0.5% segmental. 50% of all fibular neck fractures were comminuted, followed by 27% transverse, 12.2% oblique, 6.8% avulsion, 2.7% segmental, and 1.5% bone contusion. 41.2% of fibular shaft fractures were comminuted, 23.5% transverse, 23.5% oblique, 5.9% avulsion, and 5.9% bone contusion. The most typical tibial plateau patterns associated with proximal fibular injurye were bicondylar fracture dislocations Schatzker VI and Schatzker V with a proximal fibular injury incidence of 78.4% and 68.6%, respectively. We detected femoral condyle injuries in 56% of the cases and, interestingly, in 93% of all cases, the lesion was not indentibiable by regular radiographs. Bony contusion was the most common injury pattern (62% lateral and 60% medial). Subchondral impaction was the second most common condylar injury (23.9% lateral and 20.3% medial). Half of the associated femoral condyle injuries were found in Schatzker type II and VI tibial plateau fractures (25.8% and 24.9% respectively). The lateral femoral condyle was more frequently involved compared to medial (75.6%vs38.5%; p<0.05) and was more frequently associated with type II (29.7%) and VI (27.1%) tibial plateau fractures. The incidence of hidden injuries, which were only detemined by MRI, The clinical relevance of these findings should be further investigated, such as the possible correlation between these injuries and the development of post-traumatic arthritic changes in the knee.