A safe zone for the passage of screws through the posterior tibial cortex in tibial tubercle transfer.

In tibial tubercle transfer, surgery drills and screws can put the popliteal vessels at risk if the posterior cortex is breached. This complication can be devastating. We have looked at arteriograms of 50 knees and identified a safe zone through which an instrument can be passed with more confidence. In our study we found no vessels directly posterior to the supero-medial aspect of the proximal metaphysis in any knee. Whilst care must still be taken, this area will allow surgeons greater confidence to obtain a stronger bicortical hold with any fixation device.