Winquist-Hansen Classification of Femoral Comminution

A blocking (Poller) screw placed in the short metaphyseal fragment narrows the effective canal and re-establishes a cortical buttress, converting a metaphyseal type III/IV into a mechanically simpler pattern. It is the single most useful adjunct for comminuted proximal-third and distal-third femoral shaft fractures treated by antegrade or retrograde nailing.

Most femoral shaft fractures are nailed antegrade, and the entry point matters: the piriformis fossa is collinear with the canal but is technically harder and risks the medial femoral circumflex blood supply (and, in children, the capital epiphysis), whereas the trochanteric-tip entry is easier but - being lateral to the canal axis - risks varus/translation in proximal-third fractures unless a trochanteric-entry nail and correct start point are used. Retrograde nailing (entry through the intercondylar notch) is preferred for the distal-third fracture, the obese patient, the polytrauma patient (fast, supine, no traction table), the floating knee (one approach for femur and tibia), bilateral femurs, an ipsilateral femoral neck or acetabular fracture, and late pregnancy; it needs an intact knee and risks knee pain/stiffness/ sepsis and distal malalignment. Malalignment is highest for proximal-third fractures regardless of route (Ricci). Whatever the route, always exclude a (commonly-missed) ipsilateral femoral neck fracture.

Two choices sit alongside the locking plan and depend on the patient, not the comminution grade:

• Reamed vs unreamed: reamed nailing allows a larger, stronger nail and gives higher union rates (the standard for isolated femoral shaft fractures), but reaming raises intramedullary pressure and embolises marrow fat to the lungs - a theoretical "second hit" in the chest-injured polytrauma patient (though it is well tolerated in the isolated injury).
• Timing - early total care vs damage control: in the physiologically stable patient, early definitive nailing (within ~24 h) reduces pulmonary complications and is preferred. In the unstable or "borderline" polytrauma patient (hypothermia, coagulopathy, high lactate/base deficit, significant chest or head injury), damage-control orthopaedics - temporary spanning external fixation, converting to a nail once the physiology recovers - avoids the second hit and ARDS.

So the Winquist grade tells you how to build the construct; the patient's physiology tells you when (and whether to ream).