Observational prospective study to evaluate the feasibility, effectiveness and the rate of complications of the XLIF (Extreme Lateral Interbody Fusion) performed in prone position to treat spinal diseases of the lumbar region.

Inclusion Criteria:

• Age ≥ 18
• Patients suffering from lumbar spinal disease that requires a circumferential fusion
• Patients suitable to undergo spinal fusion with an XLIF technique (according to the label indication/contraindications)
• Patients who are willing and able to provide written informed consent to surgery and study

Exclusion Criteria:

• a congenital or post-traumatic vertebral abnormality at the target level
• patients with a previous abdominal retroperitoneal surgery
• patients that refuses/not suitable to undergo a XLIF surgery in prone position
• subjects that are unable to provide a written informed consent to surgery and study
• subjects that are unable to will or intend
• pregnant women (declared before surgery)

Patients affected by a lumbar spinal disease, indicated for surgery requiring a lateral XLIF approach to the lumbar spine, eligible to perform the approach in a prone position.