Multilevel Oblique Lumbar Interbody Fusion in Degenerative Lumbar Disc Disease with Instability

The surgical technique of L2- L5 Oblique Lumbar Interbody Fusion (OLIF), including the exposure of the surgical corridor, preparation of the disc space, and placement of the interbody cages, followed by pedicle screw fixation, is presented. To perform this technique, the patient is positioned in right lateral decubitus on a radiolucent table, and an oblique incision is made 3-5 cm anterior to the middle of the L3-L4 disc space. After dissecting the subcutaneous fat, the external oblique aponeurosis is cut along the line of the incision and the oblique muscles (external and internal), and the transversus abdominis muscles are split along the direction of the muscle fibers. Peritoneal fat is gently swept anteriorly until the psoas muscle is visualized. The psoas muscle is then retracted posteriorly to reveal the underlying disc space. A guide wire is inserted into the disc, followed by sequential dilators and placement of expandable retractors. After confirming the retractor position, annulotomy is performed, and the disc space is prepared using a combination of Cobb's elevator, curettes, and pituitary rongeurs, employing an orthogonal maneuver. Under the fluoroscopy guidance, serial trials are introduced, and an optimal-sized cage packed with bone graft substitutes is implanted into the disc space. The same steps are repeated at two adjacent levels (L2-L3, L4-L5), and the wound is closed in layers. The patient is turned into a prone position and pedicle screws are placed to complete the construct. The results of 30 patients who underwent this OLIF procedure were analyzed. The mean disc height was 7.47 ± 2.3 mm, which significantly increased to 10.9 ± 2.7 mm postoperatively (p < 0.0001). Similarly, the mean disc angle improved from 7.26° ± 6.2° to 9.81° ± 4.1° (p = 0.0065). At the final follow-up, both disc height and angle were maintained, along with satisfactory bony fusion, with no cases of pseudoarthrosis or implant failure.