Fixation of Segmental Femoral fracture using Poller (Blocking) screws
- Advanced Technique
Segmental femoral fractures can be difficult to fix and heal. Antegrade nailing is probably the easiest method for segmental femoral fracture fixation although it has certain difficulties particularly if one of the fractures is in the subtrochanteric area (which usually is). Obliquity of the proximal fracture is adding an additional problem to the fixation.
Standard nailing will always push proximal fragment into VARUS (X-ray below). This will prevent conversion of share forces into compression forces. Failing to do so will very likely result in a non-union.
We certainly can say that one of the fractures (segmental configuration) will very likely anyway end in non-union.
My question is:" Why does one of the fractures in the segmental femur or tibia end in non-union?"
I believe that I understand why one of the segmental fractures will end in non-union (in my opinion everything is related to the energy involved during the fracturing (breaking) process). Suboptimal fixation certainly does not always help the healing process. So....
Standard nailing will always push proximal fragment into VARUS (X-ray below). This will prevent conversion of share forces into compression forces. Failing to do so will very likely result in a non-union.
We certainly can say that one of the fractures (segmental configuration) will very likely anyway end in non-union.
My question is:" Why does one of the fractures in the segmental femur or tibia end in non-union?"
I believe that I understand why one of the segmental fractures will end in non-union (in my opinion everything is related to the energy involved during the fracturing (breaking) process). Suboptimal fixation certainly does not always help the healing process. So....
X-rays of the fractures are not high quality. Would better imaging make any difference to the treatment? Probably not.
How I use Poller (Blocking) screw in antegrade nailing for segmental femoral fractures is presented below.
How I use Poller (Blocking) screw in antegrade nailing for segmental femoral fractures is presented below.
As you can see from the slideshow I had to put a second poller screw after the first one failed completely to reduce the fracture. Some surgeons would say that the position of the fracture after first poller screw and the nail was acceptable. This is very likely true but in my experiences vast majority of fractures fixed with such a displacement (in translation:"not neutralised share forces") will end up in non-union. Consequent revisions are possible but difficult.
If you do not want to use poller screw(s) than open reduction, clamp and cerclage wire or cable are be the option.
Two images below are depicting differences in reduction after first and after second poller screw insertion. Obvious difference.
It is also obvious that the first poller screw is not doing anything and this is how the fracture would look like even the screw had not been placed. Even the broader diameter of the top of the nail did not engage the poller screw.
If you do not want to use poller screw(s) than open reduction, clamp and cerclage wire or cable are be the option.
Two images below are depicting differences in reduction after first and after second poller screw insertion. Obvious difference.
It is also obvious that the first poller screw is not doing anything and this is how the fracture would look like even the screw had not been placed. Even the broader diameter of the top of the nail did not engage the poller screw.
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