Zugkraftmessungen beim knöchernen Segmenttransport – in vivo Untersuchungen am Menschen

Bone transport applying the principle of distraction osteogenesis
makes it possible to reconstruct long bone defects caused by trauma
or resection of bone tumors. The method employing a central cable,
developed in Munich, is especially suitable for such applications.
The main bone fragments are stabilized by an external fixateur, and
bone transport is effected with a single central cable fixed to the
tip of the segment, and driven by an external, programmable motor.
In 15 patients the tractive forces during the entire bone transport
were measured with a strain gauge incorporated within the cable. On
the basis of the force profiles characteristics normal bone
transport (forces between 150 - 250 N) can be distinguished from a
critical transport (forces > 250 N) with the risk of premature
consolidation. There is some evidence that at a very high level of
force, just before premature consolidation a very effective form of
bone transport with good bone neoformation can be achieved.
Transport systems employing a central cable allow this special form
of distraction osteogenesis, since there is continuous force
monitoring, and there is the option of employing the traction force
as a control factor in a loop.