A retrospective CT study characterizing the posteromedial fragment in bicondylar tibial plateau fractures. It quantifies how often the fragment occurs, how large it is, and how it is oriented. The goal is to inform surgical approach and fixation choices for this commonly overlooked fracture component.
When you see a bicondylar tibial plateau fracture, assume a posteromedial fragment is present until CT proves otherwise. It shows up in nearly 6 of 10 cases and involves a quarter of the joint surface.
The key mental model is shear. With a mean sagittal angle of 73 degrees, this fragment behaves like a vertical shear plane that slides distally under body weight, pulling the medial femoral condyle into posterior subluxation.
Lateral locking screws can sometimes cross the fracture line, but crossing it is not the same as buttressing it. A vertical shear surface needs a medial or posteromedial buttress plate to resist displacement.
The MAFA teaches when lateral fixation may fail: externally rotated fragments sit within screw reach, while internally rotated or directly posterior fragments escape lateral screws and demand a dedicated posteromedial approach.
Context for weighting: this is a descriptive retrospective series with unblinded review, but its morphology closely matches the Barei data, strengthening the case that this fragment is real and undertreated.
A retrospective CT study characterizing the posteromedial fragment in bicondylar tibial plateau fractures. It quantifies how often the fragment occurs, how large it is, and how it is oriented. The goal is to inform surgical approach and fixation choices for this commonly overlooked fracture component.
When you see a bicondylar tibial plateau fracture, assume a posteromedial fragment is present until CT proves otherwise. It shows up in nearly 6 of 10 cases and involves a quarter of the joint surface.
The key mental model is shear. With a mean sagittal angle of 73 degrees, this fragment behaves like a vertical shear plane that slides distally under body weight, pulling the medial femoral condyle into posterior subluxation.
Lateral locking screws can sometimes cross the fracture line, but crossing it is not the same as buttressing it. A vertical shear surface needs a medial or posteromedial buttress plate to resist displacement.
The MAFA teaches when lateral fixation may fail: externally rotated fragments sit within screw reach, while internally rotated or directly posterior fragments escape lateral screws and demand a dedicated posteromedial approach.
Context for weighting: this is a descriptive retrospective series with unblinded review, but its morphology closely matches the Barei data, strengthening the case that this fragment is real and undertreated.