Hoffa Fractures

Lag screws compress the fragment but do not neutralise shear, and the decision to add a plate is driven by the Letenneur fracture geometry. Types I and III have a near-vertical fracture line — the load across the condyle is largely shear, the fragment tends to slide proximally, and lag screws alone may fail — whereas type II is more transverse and is well controlled by interfragmentary lag screws alone. For the vertical types, a small posterior buttress (antiglide) plate applied along the posterior cortex converts shear into compression and resists proximal migration of the fragment, the same antiglide principle used for posterior malleolar and proximal-ulna fractures. A buttress plate is also added for comminution. The plate sits posteriorly (requiring posterior access) while lag screws provide interfragmentary compression.

The approach must deliver what the construct needs. A standard lateral or anterolateral (e.g. Swashbuckler) approach gives good articular visualisation and easily permits anterior-to-posterior or oblique screws, but it does NOT allow a true posterior-to-anterior screw or a posterior buttress plate. To place the biomechanically preferred P-A lag screws and a posterior antiglide plate, a dedicated posterior approach is required: a posterolateral approach (protecting the common peroneal nerve) for the lateral condyle, a posteromedial approach (protecting the saphenous nerve and vessels) for the medial condyle, or a direct posterior (Lobenhoffer) approach for posterior or bicondylar fragments, with lateral or prone positioning planned accordingly. The logic runs one way: decide whether the fracture geometry needs a posterior buttress, then let that decision drive the approach and patient position.

Q: What is a Hoffa fracture? A: A coronal plane fracture of the posterior femoral condyle. The fracture line runs in the coronal plane, separating the posterior condyle from the anterior condyle and shaft.

Q: Why are Hoffa fractures frequently missed on plain X-rays? A: The fracture occurs in the coronal plane, which is parallel to the X-ray beam on AP view and tangential on lateral view. CT with sagittal reconstructions is required for diagnosis.

Q: Why is the Hoffa fragment essentially avascular? A: The fragment has no anterior soft tissue attachments (capsule, ligaments) and only posterior periosteum. It is essentially a free bone fragment relying on fixation-mediated healing.

Q: Why should screws be placed posterior-to-anterior in Hoffa fracture fixation? A: P-A screw placement puts the threads in the well-vascularized intact bone rather than the avascular fragment, providing better purchase. The screw heads are also easier to countersink posteriorly.

Q: In a combined Hoffa and supracondylar fracture, which component should be fixed first? A: Fix the Hoffa fracture first. This reconstitutes the condyle anatomy, creating a solid block to which the shaft can then be reduced and fixed.