In case of fractures of smaller bones - particularly in case of the comminuted fracture dispositions - the optimal fixing direction can be diverse. In this case, neither the traditional AO-screws, nor the locking screws provide satisfactory result. Instead of these, polyaxial technique can be used.
Medimetal offers two different types of polyaxial plate systems.
As per the functioning method of the first-type polyaxial plate system, lamellas are designed to be located in the holes of the plate. The plates are relatively thin, thus they are suitable for fractures of smaller bones with low biomechanical loading (e.g. in case of hand-, arm- and shoulder surgeries). The linking of the lamellas and the screw allows the surgent to choose the screwing direction with +/- 15° degree of freedom. This polyaxial range ensures that the special screw head and the lamellas are linked, and that the lamellas – due to their deformation –safely hold the chosen direction of the screw. In case of some plates cannulated screwing technique can also be used.
The second-type polyaxial plate system offers a big portfolio of plates for the well-known small and large fragments. According to this, the plate thickness varies within a wide load-bearing range. The polyaxial fixation happens with the help of special threaded holes. The teething gaps in the hole-thread ensure that the special threaded screw-heads are fixed within the +/-15° axis evasion range.