Spinal Disorders: Fundamentals of Diagnosis and Treatment Part 12. Spinal disorders are among the most common medical conditions with significant impact on health related quality of life, use of health care resources and socio-economic costs. Spinal surgery is still one of the fastest growing areas in clinical medicine. | Spinal Instrumentation Chapter 3 85 Corpectomy fusion technique. Spinal instability after corpectomy or after vertebrectomy in the lumbar spine often requires complex reconstructive procedures. The type and degree of instrumentation depend strongly on the number of involved levels and the retained functioning stabilizing structures. Generally after corpectomy anterior support is mandatory and long-term stability cannot be achieved with rod pedicle screw instrumentation alone. Furthermore the combination with an anterior tension band device still exhibits a certain instability in extension and rotation. Therefore from the biomechanical perspective substantial anterior instability requires front and back instrumentation. In the cervical spine however single-level cage stabilization is sufficiently supported by an anterior tension band device. Multiple-level cervical corpectomies are particularly unstable and anterior plating may be insufficient consequently additional pedi-cle lateral mass screw devices must be considered. Anterior tension band technique. Anterior rods plates act as tension bands in extension and function as buttress plates in flexion. For the cervical spine the latest generation of semi-constrained dynamic plates allow locked angle-stable monocortical screw fixation while axial compression of the graft is permitted. This offers increased stability combined with a minimized risk of stress-shielding. In the lumbar spine anterior rod double-rod instrumentation increases anterior stability after cage or graft implantation especially in extension. In flexion and lateral bending they are still inferior to pedicle screw devices. Biomechanics of the adjacent segment Unphysi-ologically long and stiff spinal segments increase motion and intradiscal pressure in the adjacent segments. However it is still unclear if adjacent segment degeneration after spinal fusion is resulting from the changed biomechanics or exhibits simply the progression of the natural .
