[Minimally Invasive Extraforaminal Lumbar Interbody Fusion]

Objectives: The objective of the present study was to determine the indications, surgical technique, results, and complications of minimally invasive extraforaminal lumbar interbody fusion (ELIF).

Introduction: ELIF is characterized as removal of the superior articular process (SAP) to access the intra-canalicular root and disc through Kambin's triangle.

Methods: A retrospective study was conducted of 40 patients operated upon between 2013 and 2015. Patients with low back pain or root pain due to degenerative disc disease, spondylolisthesis grade 1 and 2, recurrent disc herniation, and recess-foraminal stenosis were included. A visual analogue scale (VAS), the Oswestry index, the Weiner scale and the modified MacNab criteria were used to assess pain, clinical and functional results and patient satisfaction one year after surgery. Complications were documented and rated according to their severity, in four degrees.

Results: We operated on 25 women and 15 men of average age 57 years. Of the forty, 47.5% were treated for spondylolisthesis, 25% by recess foraminal stenosis. In total, 54 interbody cages and 188 percutaneous pedicle screws were placed; and the mean duration of surgery was 245 (±25.4) minutes. The mean hospitalization time was 3.5 (±0.49) days. We observed nine Grade 1 and one Grade 2 complication. The mean preoperative ODI score was 51.9 ± 4.96, which improved to 12.2 ± 3.19 at one year ( < 0.0001). The mean VAS low back pain rating improved from 8.81 ± 0.62 to 2.12 ± 0.89 ( < 0.0001). By one year post-operatively, 77.5% of the patients had fusion (Bridwell grade 1 or 2).

Conclusions: ELIF is a safe and effective surgical approach. Satisfactory clinical outcomes, comparable to traditional techniques, can be achieved with facet resection limited to the superior articular process.