[Single segment internal fixator device in treatment of thoracolumbar vertebral fractures].

Treatment of vertebral fractures by the fixed-angle system of the internal fixator allows fusion over a short area and is the form of treatment now in general use. A bisegmental construction is usual, which means that reduction and relief of the injured vertebral body is achieved indirectly by means of two intact vertebrae immediately adjacent on either side. As a result, both segments stiffen up or are permanently damaged in their function. We report on the possibility of single-segment fixation. The principle is the fusion of the injured segment itself only, i.e., the vertebra actually injured and the vertebra adjacent to the injured segment. Unnecessary fixation of a second healthy segment can thus be avoided. The characteristics of the fracture type in which single-segment stabilization is possible are explained. In a small study of the technique, we used the new AO classification of vertebral fractures of the thoracolumbar spine. The operation technique differs in some details from that applied with a multisegmental internal fixator. For example, the pedicle screws occasionally need to be inserted extremely close to the end-plates if the remaining part of the vertebral body has been destroyed and therefore cannot provide stability. Contraindications are broken pedicles and complete burst fractures of the body. With due consideration for these limitations fractures in all three main groups of the AO classification can, in principle, be stabilized in a single segment. In the years 1988-1990, 14 patients were operated on in this way (12 acute injuries, 2 secondary operations).(ABSTRACT TRUNCATED AT 250 WORDS)