In order to gain a better understanding of the healing processes after plat
e fixation and indirect reduction, Baumgaertel designed a reproducible frac
ture model for the sheep femur in 1992 so that the differences between anat
omical (rigid) and biological (bridging) fixation could be investigated. It
was demonstrated that indirect reduction and bridge plating was superior t
o direct fragment reduction and anatomical fixation in respect to radiology
, biomechanics and microangiography. in this study, it was shown that bony
bridging of the fracture gap and mineralization of callus occurred faster a
nd more efficiently after indirect than after direct and anatomical reducti
on. Bone healing was identified as beginning in the 2.-3. week after indire
ct and only in the sixth week after direct reduction. The increased breakin
g strength of the indirectly reduced femora at 8 weeks can be attributed to
this process. In addition, the consequences of applying the PC-Fix for bio
logical plating were investigated. The values for bone healing were improve
d by applying a plate with only point contact to the bone, thus conserving
the periosteal blood supply.