Lateral Lumbar Interbody Fusion

Ankur S. Narain, Fady Y. Hijji, Philip K. Louie, Daniel D. Bohl, and Kern Singh

23.1 Case Presentation

A 55-year-old man presents to the clinic complaining of an 8-month history of gradually worsening low back pain. The patient notes bilateral lower extremity radiculopathy radiating to the anteromedial thigh. He has failed multiple trials of physical therapy and steroidal injections. On physical examination, the patient is noted to exhibit a sensory loss on the right anterior thigh. The patient’s radiographs and magnetic resonance imaging (MRI) findings are shown in Figs. 23.1 and 23.2. The surgeon schedules the patient for a lateral lumbar interbody fusion (LLIF).

23.2 Indications

• Lumbar nerve root compression above the level of the iliac crest.

• Lumbar instability.

• Tumors.

• Infection or anterior lumbar abscess.

23.3 Positioning

• Lateral decubitus position.

• Superficial landmarks include:

– Ribs and associated intercostal spaces.

– Pubic symphysis.

– Lateral border of rectus abdominis muscle:

∘ 5 cm lateral to midline.

– Spinous processes of desired levels.

Fig. 23.1 Anteroposterior (a) and lateral (b) lumbar radiographs. Significant spondylosis is apparent at the L2–L3 disk level with radial and anterior osteophyte formation. Note the concurrent retrolisthesis of L2 over L3.

Fig. 23.2 Sagittal (a) and axial (b) cuts of a T2-weighted lumbar MRI. There is significant degeneration of the L2–L3 disk with moderate bilateral foraminal stenosis.

23.4 Approach

• Superficial dissection:

– Skin incision made at the lateral aspect of the desired level:

∘ Fluoroscopy used to determine appropriate level.

– External oblique, internal oblique, and transversalis fascia are dissected (Fig. 23.3):

∘ No true internervous plane exists in this approach; the muscles of the abdominal wall being divided are segmentally innervated.

• Deep dissection:

– Transversalis fascia is opened and retroperitoneal fat is exposed and removed.

– The psoas muscle is then identified and retracted posteriorly or traversed with careful ongoing neuromonitoring (Fig. 23.4):

∘ The lumbar plexus lies within the psoas muscle and can be injured with excessive manipulation.

– The disk space is identified and prepared.

23.5 Implants and Hardware

• The intervertebral disk is completely removed and the end plates are prepared.

• The interbody cage is impacted into the prepared disk space.

• Supplemental percutaneous posterior fixation can be performed using a posterior lumbar approach.

23.6 Case Presentation: Postoperative Outcomes and Imaging

The patient underwent an L2–L3 LLIF procedure with placement of an interbody cage and supplemental fixation using unilateral pedicle screws. Postoperatively, the patient complained of new-onset hip flexion weakness with continuing sensory loss of the anterior thigh. However, at his 3-month visit, the patient noted complete resolution of his motor weakness and sensory loss. At his 9-month follow-up, the patient notes improved lower back pain and no new onset of neurologic symptoms. Postoperative radiographs are presented in Fig. 23.5.