Grafton

This technique was performed by the author (W.L.). The patient was placed in the right lateral decubitus position. The surgical approach was performed to reach the retroperitoneal corridor between the psoas muscle and great vessels. The self-retaining retractor was placed upon the operated disk level after sequential dilators were applied. Thorough discectomy and endplate preparation were performed using the orthogonal maneuver. The appropriate-sized cage (CLYDESDALE; Medtronic) filled with DBM (GRAFTON; Medtronic) was inserted orthogonally into the operated disk space. Percutaneous posterior instrumentation was placed in prone position after completion of the lateral procedure.

The surgical technique for OLIF25 has been published previously.6) (link) Briefly, patients were positioned in the right lateral decubitus position under general anesthesia. Using C-arm imaging, a 4–5 cm oblique skin incision was made from the anterior margin of the target disc. The external oblique, internal oblique, and transverse abdominis muscles were split along directions of muscle fibers. The target disc was approached anteriorly through the retroperitoneal space, and a cage (Clydesdale; Medtronic, Minneapolis, MN, USA) packed with a demineralized bone matrix (Grafton; Medtronic, Minneapolis, MN, USA) was inserted using an orthogonal maneuver after the disc was removed. In case of multilevel surgery, the operation was performed from the lowest disc and proceeded upward by the same way as mentioned herein.

OLIF involves minimally invasive lateral interbody fusion using a left-sided retroperitoneal approach and percutaneous pedicle screw fixation.
The intervertebral disc was exposed through an open corridor between the psoas muscle and aorta. The sympathetic chain and ureter were mobilized anteriorly. The procedure was performed using an OLIF system (Medtronic, Memphis, TN, USA), fusion material (Grafton, Medtronic, Memphis, TN, USA), and a percutaneous pedicle screw fixation system (Longitude system, Medtronic, Memphis, TN, USA). We determined the height of the cage to be inserted by using the presurgery CT scan. If the intervertebral disc space was < 6 mm, a 10-mm cage was inserted. If the intervertebral disc space was ≥ 6 mm, a cage 4 mm greater than the disc height was inserted. The indirect decompression effect on the constant disc height was evaluated. We did not perform posterior decompression on any of the patients.

The surgical technique used for OLIF has been previously described at our institute [13 (link),14 (link),20 (link)]. The patients were briefly placed in the right lateral decubitus position for the left-sided retroperitoneal approach. The surgical level of the disc was marked on the skin in true lateral view under C-arm fluoroscopy. An oblique skin incision was made 3–5 cm ventral to the anterior margin of the intervertebral disc. After dissecting the 3 layers of the abdominal wall muscles, the peritoneal fat was identified. The disc annulus was exposed through an open corridor between the psoas muscle and peritoneum. At the anterior border of the psoas muscle, the plane between the disc annulus and the psoas muscle was bluntly dissected using a peanut gauze ball to not injure the psoas muscle bundle. A slight dorsal retraction of the psoas muscle was applied during tubular retractor fixation. The entire surgery was performed using a Medtronic OLIF system (Medtronic, Memphis, TN, USA) with a minimally invasive tubular retractor, fusion material (Grafton, Medtronic), and a percutaneous pedicle screw fixation system (either Sextant or Longitude system, Medtronic) (Fig. 1). Posterior decompression was not performed on any of the patients included in this study.