Tibiofemoral axial rotation in tibial plateau fractures: A retrospective radiographic assessment of 203 tibial plateau fractures.

BACKGROUND

Defining the injury-force mechanism in tibial plateau fractures (TPFs) could help define implant type and position, as well as soft tissues at risk. The aim of this study was to provide an analysis of injury-force-mechanisms in TPFs, including axial rotation.

METHODS

The injury-force mechanism was determined for 203 fractures that presented over a period of 3.5 years. Fractures were classified as flexion-varus/valgus/neutral or (hyper)-extension-varus/valgus/neutral by observing articular depression area on CT/MRI. Fractures were subclassified into rotation-neutral, internal- or external-rotation according to the Gerdy-tibial-tuberosity-surgical-epicondylar-axis (GTT-SEA) angle. Soft-tissue injury was documented if MRI was performed.

RESULTS

Flexion-valgus was the most common injury-force mechanism (n = 85, 41.9%), followed by extension-valgus (n = 57, 28.1%). Other mechanisms were less common (9.4% extension-varus, 5.9% flexion-neutral, 4.9% flexion-varus, 3.9% hyperextension-valgus, 3.4% extension-neutral and 2.5% hyperextension-varus). The GTT-SEA angle could be measured in 194 (95.6%) of 203 classified patients, revealing internal rotation in 83 (42.8%) and external rotation in 53 (27.3%). No significant difference was found between injury-force mechanism type and axial rotation group (P = 0.964) or extent of rotation (H(8) = 7.116, P = 0.524). Only 41 (21.1%) of 194 fully classified fractures underwent MRI, all revealing soft-tissue injury to some extent. High-grade posterolateral injuries occurred mainly in rotated TPF.

CONCLUSION

Our results describe the common forms of axial rotation present in TPF and explore their association with injury-force mechanism and soft-tissue injury. Applying the injury-force mechanism patterns and addressing rotational forces could, together with preoperative MRI and intra-operative stability assessment, help determine the need to surgically address associated soft-tissue injury.