Pain arising from degenerative changes in the posterior elements has long been treated with decompression or decompression combined with fusion. While decompression alone may leave the spine at risk for instability, decompression with fusion leaves it incapable of allowing motion due to the rigid fixation. We have seen the expansion of total disc replacement to address disc-related pain without fusing the spine. Such treatment holds promise to reduce the patient’s pain while allowing normal movement of the spine and minimizing the potential problem of adjacent segment deterioration. We are now witnessing the development of various treatments to address pain arising from the posterior elements. Just as with the emerging option of nucleus replacement versus total disc replacement, the development of posterior dynamic stabilization devices is taking place, such as the Dynesys System and now a step further to total posterior element replacement. One such device is the Impliant TOPS™ Total Posterior Arthroplasty System.

The TOPS™ device is designed to completely replace the posterior elements and is comprised of a titanium construct with an interlocking polycarbonate urethane (PcU) articulating core (Figs. 25.1, 25.2, 25.3). It is a unitary device that is anchored to the spine with pedicle screws using a familiar surgical technique. Specialized instrumentation has been developed to direct optimal screw placement to properly accept the device. Within the core, there are stops designed to control the degree of motion in the various planes. It allows for dynamic, multiaxial, 3-column stabilization after complete neural decompression recreating near-normal spine biomechanics.

The primary indication for total posterior replacement is moderate to severe lumbar spinal stenosis, with or without spondylolisthesis (up to grade 1) and with or without facet
hypertrophy. The TOPS™ device can be viewed as a treatment option for late-stage posterior degeneration that requires a destabilizing decompression.