Ultrasound as Adjunct Therapy for Increasing Fusion Success After Lumbar Surgery

Inclusion Criteria: * The subject has a documented diagnosis of degenerative disc disease with up to Grade I spondylolisthesis at the target level * Requires spinal fusion of a single level disc space (L2 to S1) with the use of local bone graft. * Requires a posterolateral fusion procedure with or without an interbody fusion procedure using a posterior approach * The subject has failed non-operative treatment lasting at least 6 months. Exclusion Criteria: * Requires spinal fusion at more than one lumbar level. * Is pregnant, is lactating or plans to become pregnant before discontinuation of study treatment