Summary Spinal decompression surgery (laminectomy) removes the compressive structures, including hypertrophic ligamentum flavum and lumbar facet joint osteophytes. The goals of surgical treatment are to alleviate neural compression and, in selected patients with a deformity or instability, to stabilize the spine (fusion), so as to prevent further spinal compression and recurrent symptoms.
Technique - Dissection Tissue planes are dissected along the spinous process and the laminae. Moving the paraspinal muscles laterally provides visualization of the laminae, thereby enabling exposure of the central canal and neural elements.
- Placement of Pedicle Screws In selected patients (eg, those with a deformity or spondylolisthesis), a spinal fusion with instrumentation is required. Spinal pedicle screws with connecting rods provide direct fixation into the vertebrae and increase spinal stability, thereby improving the chances of successful fusion. A successful spinal fusion requires osseous growth of the vertebrae and the bone graft together.
- Intraoperative Fluoroscopy Pedicle screws are localized by means of intraoperative fluoroscopy. The fluoroscopic image in the slide shows that the pedicle screws are in proper position.
- Triggered Electromyography (EMG) Intraoperative pedicle screw electrical stimulation is performed to confirm that the screws are not compressing or in contact with the neural elements. This facilitates identification and removal of the compression.
- Decompression Decompression of the central canal and the neural structures is begun with the rongeur, and the spinous process is removed.
- Confirmation of Screw Placement Visual inspection of the incision shows that the L4 and L5 pedicle screws are in position laterally and outside the canal.
- Rod Placement After decompression is complete, rods are placed into the pedicle screws to stabilize the spine, and set screws are tightened. Bone graft is placed laterally along the transverse process to allow an osseous fusion.
- Closure The retractors are removed and the decompression confirmed. The muscles are then brought back together, and the fascia is closed. The cutaneous layers of the incision are sutured closed.
Indications - Deteriorating neurological status - Caudal equina syndrome (Emergency) - Compression of the cord is evident on MRI - Penetrating cord injuries - Gunshot injuries - Bony fragments in the spinal canal - Unstable vertebral body
Contraindications - Severe Osteomalacia or Osteoporosis - Vertebral Fractures - Spondylolisthesis (Grade 2 or higher) - Spondylolysis - Unstable Post Surgical Conditions - Any kind of surgical hardware - Infection - Ankylosing Spondylitis - Dislocations, ligament tears or rupture - Pregnancy - Cauda Equina lesions - Neurological defecits