DESIGN FEATURES
The DynaNail TTC Fusion System maintains active compression across the joints using its proprietary internal NiTiNOL
Compressive Element that automatically responds to changes in loading due to bone resorption or settling. The stretching
and unloading of the Compressive Element can be visualized on fluoroscopy via translation of the screw holes in the
Sliding Element through the slot in the Outer Body.
Screw Hole in
Proximal Position
Out of the Package
The Compressive Element is in its unstretched position
with the calcaneal screw holes in the Sliding Element
positioned proximal in the Nail Body slot.
During Surgery
The Compressive Element is stretched using the Targeting
Frame causing the calcaneal screw holes to shift distally
in the Nail Body slot, a distance that corresponds to the
amount of desired compression. While the DynaNail Frame
holds the Compressive Element in the stretched position,
screws are placed in the calcaneus and tibia.
Stretching of
the Element
Screw Position
when Stretched
Immediate Post-Surgery
Once the Targeting Frame is removed, the Compressive
Element is now in its stretched activated position with the
calcaneal screws oriented in the distal end of the slot and
the Sliding Element extending plantarly from the Nail Body.
Post-Operatively
As the Compressive Element unloads (i.e., recovers
its stretched length) in response to bone resorption
or settling, the calcaneal screws will progressively
shift proximally. The amount of unloading can be
measured on radiograph by the position of the screws.
The Compressive Element has completely unloaded
back to its resting state when the calcaneal screws
are at the proximal end of the slot.
Screw Position
after Unloading
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