Patient Positioning
- Prone: The patient is positioned prone with bolsters placed horizontally at the chest and iliac crests.
Surgical Approach
- Routine exposure of spine: Standard subperiosteal dissection is carried out with monopolar cautery, and the paraspinal muscles attaching to the lumbosacral spinous processes are dissected free.

- Single level laminotomy/laminectomy: An S1 laminectomy is performed with bone rongeurs, and bone wax is applied to the bony edges. A midline, longitudinal durotomy is then performed.
Intervention
- Cut filum: Transection of the filum terminale with bipolar cautery and scissors detethers the spinal cord.

Closure
- Dural closure: The dura is closed with a monofilament stitch. The authors prefer a running 5.0 PDS suture.
- Muscle and fascial closure: Routine per surgeon preference.
- Skin: An absorbable monofilament running suture is used.
- Drains: The authors do not use drains.