Spinal StenosisLumbar VertebraeSpinal CordDecompression, SurgicalSpinal CanalLaminectomySpondylolisthesisCarotid StenosisAortic Valve StenosisInjections, EpiduralSpinal Cord InjuriesRadiculopathyLigamentum FlavumSpinal FusionSpinal Nerve RootsCoronary StenosisIntervertebral Disc DisplacementLumbosacral RegionSpinal DiseasesSciaticaSciatic NerveTracheal StenosisSpinal Cord CompressionPolyradiculopathyMyelographyLow Back PainSpinal NervesPain MeasurementIntermittent ClaudicationSpondylosisPeripheral NervesTreatment OutcomePyloric StenosisMitral Valve StenosisDisability EvaluationConstriction, PathologicPulmonary Valve StenosisInjections, SpinalNerve FibersBack PainCervical VertebraeAnesthetics, LocalSteroidsOptic NerveMagnetic Resonance ImagingOrthopedic ProceduresNerve Compression SyndromesNeurosurgical ProceduresSacrumFailed Back Surgery SyndromeNerve BlockNerve RegenerationEpidural SpaceCauda EquinaProstheses and ImplantsFollow-Up StudiesSpineTissue AdhesionsProspective StudiesSpinal Cord DiseasesDura MaterFluoroscopyAnesthesia, SpinalSurgical Procedures, Minimally InvasiveRetrospective StudiesSeverity of Illness IndexTomography, X-Ray ComputedChronic PainSpinal Cord NeoplasmsPeripheral Nerve InjuriesPostoperative ComplicationsSaline Solution, HypertonicPainNerve EndingsSural NerveInternal FixatorsTibial NerveThoracic VertebraeMedian NerveNerve CrushRecovery of FunctionBetamethasoneFacial NerveSpinal NeoplasmsIntervertebral Disc DegenerationLidocaineRenal Artery ObstructionUlnar NerveOrthopedic Fixation DevicesTriamcinoloneDiskectomyAchondroplasiaAortic Stenosis, SubvalvularFemoral NerveDiagnostic Techniques, NeurologicalOsteoarthritis, SpineSpinal OsteophytosisPost-Dural Puncture HeadacheAortic Stenosis, SupravalvularLipomatosis