Table 1.

A Step by Step Guide to Separation Surgery

Preparation	Insertion of a Foley catheter, a-line, connection to INM. The patient is positioned prone and fluoroscopy used to localize the skin incision. The surgical site is prepped and draped.
Exposure	Midline linear skin incision. Sub-periosteal muscle dissection exposing posterior spinal elements and the transverse processes laterally. Verification of proper level.
Instrumentation	Insertion of pedicle or lateral mass screws and connecting rods typically 2 levels above and 2 levels below the index level. This is usually performed prior to decompression.
Decompression	Posterior elements are drilled with a high-speed 3-mm match-stick burr to expose ligamentum flavum and dura.
Lateral exposure	The facet joints and bilateral pedicles are drilled until flush with vertebral body.
Dural exposure	Tenotomy scissors are used to dissect normal dural planes and resect ligament and tumor from the dura.
Resection of the PLL	The plane between the ventral dura and the PLL is clearly defined using Woodson dissector. The epidural venous plexus coagulated. The PLL is resected with care using tenotomy scissors to sharply divide the epidural ligament of Hoffman.
Ventral separation	Woodson dissector used to depress the epidural tumor component ventrally. When a large cavity is created in the vertebral body, intraoperative cement augmentation can provide anterior column support.
Confirmation	Ultrasound may be helpful in determining when adequate separation is achieved.
Closure	Meticulous hemostasis achieved, subfascial drain placed and the wound is sutured layer by layer.