The treatment of adult deformity has improved with the development and use of modern segmental instrumentation, including posterior instrumentation. However, the incidence of proximal junctional kyphosis (PJK) caused by the accelerated degeneration of the joint capsules and smaller articular processes in the proximal junctional region has also been noted.

One potential way of decreasing PJK is to decrease the structural rigidity of the construct at the top thereby providing a transition to the non-instrumented spine and allowing for less facet capsule and muscle disruption.