This is a single center, hybrid retrospective and prospective (ambispective) study to evaluate the safety and efficacy of the Facet Fixation implant.

The main objective is to evaluate the efficacy of the Facet Fixation implant compared with pedicle screw fixation to determine successful fusion in radiographic assessment at more than two years. Fusion is mainly defined as any sign of bony fusion between the facet joints or transverse processes when viewing the postoperative CT-scan at over 2 years.

The primary endpoint is the successful fusion rate in radiographic assessment at more than 2 years.

Inclusion Criteria:

• Patient is ≥ 18 years old at the time of the surgery
• The first back operation in the patient's life was for degenerative lumbar spinal stenosis
• Surgical treatment of degenerative lumbar spinal stenosis by lumbar decompression with Pedicle Screw fixation or FACET FIXation implant.
• Patient is able to understand the information related to the study
• Patient consents to participate to the clinical investigation and agrees (non-objection) on the use of his/her personal data.

Exclusion Criteria:

• Patient received FACET FIXation implant or Pedicle Screw fixation with supplemental interbody cages.
• Unilateral Pedicle Screw or FACET FIXation implant.
• Preoperative grade ≥II spondylolisthesis
• Preoperative scoliotic deviations >25°.
• Protected patient (under legal protection, deprived of liberty by judicial or administrative decision).
• Patient not covered by a social security scheme.

The study population will consist of adult patients diagnosed with degenerative lumbar spinal stenosis who underwent their first spinal operation for lumbar decompression with pedicle screws fixation or FACET FIXation implant from 2015 to 2020 (2015-2016 with Pedicle Screw and starting November 2017 with more than 2 years postop at the date of the visit with FACET FIXation implant).