The Study will be conducted in another research center. The Sponsor has changed.

This study will be conducted at Research Institute of Traumatology and Orthopedics (NRITO) n.a. Ya.L.Tsivyan, Novosibirsk, Russia.

The current study is prospective pilot clinical study to demonstrate the possibility and effectiveness of performing modified technique of MIS TLIF, supplemented by segmental vertebrotomy, to correct segmental deformity of lumbar spine.

It is expected to enroll 10 patients aged 18-70 with segmental deformity of lumbar spine, caused by degenerative spondylolisthesis and/or degenerative stenosis.

Inclusion Criteria:

• Given written Informed Consent;
• Single-level segmental deformity caused by degenerative spondylolisthesis and/or degenerative stenosis at the one level of lumbar spine L4-L5 or L5-S1;
• Mono- and/or polyradicular leg pain and/or neurogenic claudication with or without back pain;
• Symptoms persisting for at least three months prior to surgery;
• Able and agree to fully comply with the clinical protocol and willing to adhere to follow-up schedule and requirements.

Exclusion Criteria:

• Lumbar deformation of non-degenerative etiology;
• Spondylolisthesis grade II or higher (25% slip or greater) of any etiology;
• Patient that has already undergone a lumbar fusion surgery;
• Other non-degenerative spinal conditions (e.g. infectious, traumatic, metabolic, inflammatory, neoplastic, structural or other pathology) that may have an impact on subject safety, wellbeing or the intent and conduct of the study
• Concurrent participation in another clinical study that may confound study results.