Cervical Vertebrae/surgery; Coated Materials, Biocompatible/therapeutic use; Internal Fixators/trends; Intervertebral Disc Displacement/surgery; Ketones/therapeutic use; Polyethylene Glycols/therapeutic use; Spinal Fusion/instrumentation; Spinal Fusion/methods; Adult; Aged; Benzophenones; Bone Regeneration/physiology; Bone Substitutes/adverse effects; Bone Substitutes/standards; Bone Substitutes/therapeutic use; Ceramics/adverse effects; Ceramics/standards; Ceramics/therapeutic use; Cervical Vertebrae/diagnostic imaging; Cervical Vertebrae/pathology; Coated Materials, Biocompatible/adverse effects; Coated Materials, Biocompatible/standards; Female; Humans; Hydroxyapatites/adverse effects; Hydroxyapatites/standards; Hydroxyapatites/therapeutic use; Internal Fixators/adverse effects; Internal Fixators/standards; Intervertebral Disc/pathology; Intervertebral Disc/surgery; Intervertebral Disc Displacement/diagnostic imaging; Intervertebral Disc Displacement/physiopathology; Ketones/adverse effects; Ketones/standards; Length of Stay; Male; Middle Aged; Neck Pain/etiology; Neck Pain/surgery; Patient Satisfaction; Polyethylene Glycols/adverse effects; Polyethylene Glycols/standards; Polymers; Postoperative Complications; Radiculopathy/etiology; Radiculopathy/surgery; Radiography; Retrospective Studies; Spinal Fusion/adverse effects; Treatment Outcome