[Dorsal fixation of the thoracic and lumbar spine with grooved plates in combination with the Universal Spine Instrumentation System. A short stretch, angle-stable alternative].

In the Department of Surgery in the University Hospital "Bergmannsheil" in Bochum, 67 patients with unstable injuries of the thoracic and lumbar spine were analyzed in a retrospective study. The sagittal correction loss was greatest about 6 months after dorsal stabilization--6 degrees on the average--after stabilization with a plate alone. The correction loss after stabilization with plates combined with the Universal Spine Instrumentation System (USIS), which was developed for ventral derotational spondylodesis or after implantation of an internal fixation device, however, amounted to 3 degrees on the average. The clinical results show that by combining the plate and USIS the injuries can be stabilized for short stretches and without correction loss. The main advantage of this combination over internal fixation is the smaller amount of metal used, which means the soft tissue in loss compromised and there is a possibility of fitting the implant more directly. In 10 patients (15%) the implants broke at the place of maximum shear stress between 4 and 8 months postoperatively after consolidation of the fracture and without spoiling the result. This occurred equally often with all types of implants. Efficient use of the three systems is discussed with regard to the different pathomechanical modes of injury. A causative scheme of treatment is presented.