Short-term Clinical Outcome of Cortical Bone Trajectory Compared With the Traditional "Open" and Minimal Invasive Posterior Lumbar Interbody Fusion

Inclusion Criteria: * 18-75 years * Degenerative or spondylolytic spondylolisthesis * Neurogenic claudication and/or radicular leg pain * Low grade (Meyerding grade l and ll) * Persistent complaints for over 3 months Exclusion Criteria: * Previous spine fusion surgery at the same level * Osteoporosis * Active infection or prior infection at the surgical site * Active cancer * Spondylolisthesis grade lll or greater * More than one symptomatic level that needs fusion * Pregnancy * Contraindication for surgery * Severe mental or psychiatric disorder * Substance abuse * Inadequate knowledge of Dutch language * Morbid obesity (body mass index \>40)