[Proper and improper tension band fixation exemplified by patellar fracture].

The tension band, performed with rigid cerclage wire, is known worldwide as a standard operation technique for the patella fracture as well as for all fractures gaping under strong muscular tensile forces. Eccentricity of power input and transformation of tension into pressure forces are its theoretical rationale. This is a contradiction to the knowledge of engineers. Its disadvantages are: tilting and rolling-out, steps and gaps in the cartilage surface and distraction. Rigid cerclage wire is not a tensile instrument. Corresponding to this, the results are only mediocre. Here we describe a static tension band principle, consisting of axial power input by 2 lateral cables. The very good and good X-ray and functional results amount to 78%, far exceeding the rate with the conventional wire tension band.