Medicine, Spinal Fusion - methods, Instrumented fusion, Coralline hydroxyapatite, Lumbar spinal stenosis, Lumbar Vertebrae - surgery, Spinal Stenosis - surgery, Hydroxyapatites - administration & dosage, Spinal Stenosis - radiography, Spinal Fusion - instrumentation, Spinal Stenosis - drug therapy, Bone Substitutes - administration & dosage