Spinal DiseasesSpinal NeoplasmsIntervertebral Disc DegenerationSpondylitis, AnkylosingSpinal CordLumbar VertebraeSpinal Cord InjuriesInjections, SpinalSpinal NervesAnesthesia, SpinalSpinal Cord DiseasesSpinal Cord NeoplasmsSpinal Nerve RootsSpinal CanalSpinal Cord CompressionSpinal FusionSpinal StenosisPostoperative ComplicationsTreatment OutcomeBariatric Surgery