The PITBULL® system is intended to be used to help provide immobilization and stabilization of spinal segments as an adjunct to fusion of the thoracic, lumbar, and/or sacral spine. The PITBULL® is a posterior, non-pedicle supple-mental fixation device intended for use with an interbody cage as an adjunct to fusion at a single level in the lumbar spine (LI - SI). It is intended for attachment to the spinous processes for the purpose of achieving stabilization to promote fusion in patients with degenerative disc disease -defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies -with up to Grade 1 spondy- lolisthesis. Note Due to device placement between the spinous processes, there is a risk for spinous process fracture or other adverse event at the device interface with the spinous process.