[Pelvic girdle fractures--must they be stabilized?].

Osteosynthesis can only be successful in the pelvis if one has a biomechanical understanding of the physiological flux of force from the neck of the femur via the acetabular fossa to the sacroiliac joint. The sacroiliac ligaments have a particularly important support function here. For assessing stability and classifying the traumatic patterns it is helpful to use Pennal's classification, which takes the direction of the action of force into account. Three basic forms can be distinguished: anteroposterior compression, lateral compression and vertical avulsion. Depending on the extent of the traumatic pattern one can distinguish three subtypes. Type 1 is treated conservatively while types 2 and 3 require surgical treatment. The traumatic patterns and treatment techniques applied are described clearly and with good illustrations.