The management of lumbar instability has evolved over the past 20 years based on a better understanding of the biomechanics of the lumbar spine, the advent of computed tomography, and the development of improved internal spinal stabilization instrumentation. Surgical management presently allows for decompression of the neural elements from the anterior, posterior, or lateral aspects. The lumbar vertebral column may be stabilized by anterior and posterior lateral arthrodeses augmented with anterior instrumentation or posterior instrumentation, or both, which may be used to produce distraction or compression by using various hooks and rods and pedicle screw fixation. Bony arthrodesis of the unstable lumbar segment remains the cardinal principle of management.